JP3870951B2 - Refrigeration cycle apparatus and control method thereof - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus including an expander and a control method.

The ozone depletion coefficient is zero and the global warming coefficient is much smaller than chlorofluorocarbons.
In recent years, a refrigeration cycle apparatus using carbon dioxide (hereinafter referred to as CO ₂ ) as a refrigerant has attracted attention, but CO ₂ refrigerant has a critical temperature as low as 31.06 ° C., and uses a temperature higher than this temperature. Is in a supercritical state where the condensation of CO ₂ refrigerant does not occur on the high pressure side (compressor outlet-radiator-decompressor inlet) of the refrigeration cycle apparatus, and the operating efficiency (COP) of the refrigeration cycle apparatus compared to conventional refrigerants Has a characteristic of lowering. Therefore, in the refrigeration cycle apparatus using the CO ₂ refrigerant, it is important to maintain the optimum COP, and it is necessary to adjust the COP to the highest pressure at which the COP is optimal according to changes in the refrigerant temperature. is there.

  On the other hand, in order to improve the COP of the refrigeration cycle apparatus, a refrigeration cycle has been proposed in which an expander is provided instead of a decompressor and pressure energy during expansion is recovered as power. In a refrigeration cycle apparatus equipped with a conventional expander, the mass circulation amount of the circulating refrigerant is the same at any point in the refrigeration cycle, the suction density of the refrigerant flowing through the compressor is DC, and the suction density of the refrigerant flowing through the expander is When DE is used, operation is always performed with a constant DE / DC (density ratio). (Hereinafter, this is referred to as “constant density ratio constant”) For this reason, when an expander is provided in the refrigeration cycle apparatus and the power recovered by the expander is used as part of the driving force of the compressor It is difficult to maintain an optimal COP when the operating conditions change. Alternatively, the expander is often a positive displacement type, and since the compression ratio is substantially fixed, it is difficult to adjust the pressure to a high pressure side pressure that provides an optimum COP.

Thus, a configuration has been proposed in which an optimum COP is maintained by providing a bypass pipe that bypasses the expander and controlling the amount of refrigerant flowing into the expansion mechanism (see, for example, Patent Document 1 and Patent Document 2). .
JP 2000-234814 A JP 2001-116371 A

  However, as the amount of mass circulation flowing into the expander increases with the design optimum mass circulation amount, the mass circulation amount passing through the bypass increases, and as a result, sufficient power can be recovered. It has a problem that it cannot be done.

  Therefore, the present invention provides a refrigeration cycle apparatus and control capable of obtaining a high power recovery effect in a wide operating range without reducing the mass circulation amount flowing through the expander, and enabling efficient operation without impairing reliability. It aims to provide a method.

  In order to solve the above-described conventional problems, the present invention provides at least a compression mechanism for compressing a refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, and a power by depressurizing the refrigerant flowing out of the radiator. The expansion mechanism to be recovered, the auxiliary compression mechanism driven by the recovery power of the expansion mechanism, the expansion mechanism, the gas-liquid separator communicating with the auxiliary compression mechanism, and the liquid refrigerant flowing out from the gas-liquid separator is decompressed A first pressure reducer, and an evaporator for evaporating the refrigerant depressurized by the first depressurizer, and a medium-pressure refrigerant that is a refrigerant depressurized by the expansion mechanism and a pressure boosted by the auxiliary compression mechanism Is separated into gas refrigerant and liquid refrigerant by the gas-liquid separator, and the intermediate-pressure refrigerant is bypassed to the low-pressure side circuit until it is decompressed by the first decompressor and sucked into the auxiliary compression mechanism When Even in a refrigeration cycle apparatus that uses an expander that is difficult to maintain an optimal COP due to a constant density ratio restriction, the refrigerant is divided into two flows by a gas-liquid separator and expanded. By changing the ratio of the mass circulation amount that flows through each of the mechanism and the auxiliary compression mechanism, the restriction of a constant density ratio can be relaxed, and a high power recovery effect can be obtained within a wide operating range. Efficient operation is possible.

  The present invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. A bypass circuit that bypasses the low pressure side circuit until the pressure is reduced by the pressure reducer and sucked into the auxiliary compression mechanism, and the pressure at any position between the outlet of the compression mechanism and the inlet of the expansion mechanism The heat dissipation The opening of the first pressure reducer is adjusted so that the target high pressure side pressure is predetermined according to the temperature at any position between the outlet of the expansion mechanism and the inlet of the expansion mechanism. Even with a refrigeration cycle apparatus that uses an expander that is difficult to adjust to the high-pressure side pressure, which is the optimal COP, in the control method of the refrigeration cycle apparatus, the density ratio is constant by changing the intermediate pressure. The refrigeration cycle apparatus can be operated efficiently by adjusting the high-pressure side pressure while relaxing the above.

The present invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus including a bypass circuit that is bypassed to a low-pressure side circuit until the pressure is reduced by the pressure reducer and sucked into the auxiliary compression mechanism, the discharge temperature of the compression mechanism is set to a predetermined target discharge temperature. As described above, the refrigeration cycle apparatus control method is characterized by adjusting the opening of the first pressure reducer, and is a refrigeration cycle apparatus using an expander that is difficult to adjust to an optimum discharge temperature. However, it is possible to efficiently operate the refrigeration cycle apparatus by adjusting the discharge temperature while relaxing the restriction of the constant density ratio by changing the intermediate pressure.
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  The present invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus comprising a bypass circuit that is bypassed to a low-pressure side circuit from which the pressure is reduced by the pressure reducer until it is sucked into the auxiliary compression mechanism, the suction superheat degree of the auxiliary compression mechanism is a predetermined target superheat degree The refrigeration cycle apparatus control method is characterized in that the opening degree of the first pressure reducer is adjusted. Even in the refrigeration cycle apparatus using an expander, the density ratio is changed by changing the intermediate pressure. An efficient operation of the refrigeration cycle apparatus is possible by adjusting the degree of superheat of the auxiliary compressor while alleviating certain restrictions.

The present invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus comprising a bypass circuit for bypassing to a low-pressure side circuit until the pressure is reduced by a pressure reducer and sucked into the auxiliary compression mechanism, one of the outlet between the compression mechanism and the expansion mechanism Circulation that flows through the expansion mechanism so that the pressure at the position becomes a target high-pressure side pressure that is predetermined according to the temperature at any position between the outlet of the radiator and the inlet of the expansion mechanism This is a control method for a refrigeration cycle apparatus, characterized in that the ratio between the amount and the amount of circulation flowing through the auxiliary compression mechanism is adjusted, and an expander that is difficult to adjust to the high-pressure side pressure that is the optimum COP is used. Even in the conventional refrigeration cycle apparatus, it is possible to efficiently operate the refrigeration cycle apparatus by adjusting the high-pressure side pressure while relaxing the restriction of the constant density ratio by changing the intermediate pressure.
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  The present invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus including a bypass circuit that is bypassed to a low-pressure circuit until the pressure is reduced by the pressure reducer and sucked into the auxiliary compression mechanism, the discharge temperature of the compression mechanism becomes a predetermined target discharge temperature. As described above, it is difficult to adjust to the optimum discharge temperature with the control method of the refrigeration cycle apparatus characterized by adjusting the ratio of the circulation amount flowing through the expansion mechanism and the circulation amount flowing through the auxiliary compression mechanism. Even a refrigeration cycle apparatus using a certain expander can efficiently operate the refrigeration cycle apparatus by adjusting the discharge temperature while relaxing the restriction of the constant density ratio by changing the intermediate pressure. is there.

  The present invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus comprising a bypass circuit that is bypassed to a low-pressure side circuit from which the pressure is reduced by the pressure reducer until it is sucked into the auxiliary compression mechanism, the suction superheat degree of the auxiliary compression mechanism is a predetermined target superheat degree The refrigeration cycle apparatus using the expander is a control method for a refrigeration cycle apparatus, characterized in that the ratio of the circulation amount flowing through the expansion mechanism and the circulation amount flowing through the auxiliary compression mechanism is adjusted. However, it is possible to efficiently operate the refrigeration cycle apparatus by adjusting the superheat degree of the auxiliary compressor while relaxing the restriction of the constant density ratio by changing the intermediate pressure.

  According to the present invention, a refrigeration cycle apparatus capable of obtaining a high power recovery effect in a wide operation range without reducing the mass circulation amount flowing through the expander, and enabling efficient operation without impairing reliability, and A control method can be provided.

The first invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism driven by the recovery power of the expansion mechanism, the expansion mechanism, a gas-liquid separator communicating with the auxiliary compression mechanism, a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator, An evaporator for evaporating the refrigerant depressurized by the first depressurizer, and an intermediate pressure refrigerant, which is a refrigerant depressurized by the expansion mechanism or a pressure increased by the auxiliary compression mechanism, in the gas-liquid separator. The refrigerant is separated into a gas refrigerant and a liquid refrigerant, and the intermediate pressure refrigerant is bypassed to a low-pressure side circuit until it is decompressed by the first decompressor and sucked into the auxiliary compression mechanism. Certain system Even in a refrigeration cycle apparatus using an expander where it is difficult to maintain an optimum COP, the refrigerant is divided into two flows by the gas-liquid separator, and the mass flowing through each of the expansion mechanism and the auxiliary compression mechanism By changing the ratio of the circulation rate, it is possible to relax the restriction of a constant density ratio and to obtain a high power recovery effect within a wide operation range, so that the refrigeration cycle apparatus can be operated efficiently.

  According to a second aspect of the present invention, there is provided a high pressure side pressure detecting means for detecting pressure at any position between the outlet of the compression mechanism and the inlet of the expansion mechanism, and between the outlet of the radiator and the inlet of the expansion mechanism. A radiator outlet temperature detecting means for detecting the temperature at any position, and the pressure detected by the high pressure side pressure detecting means is a target predetermined according to the detected temperature of the radiator outlet temperature detecting means An expander that is provided with first decompressor calculation operation means for adjusting the opening of the first decompressor so as to obtain a high pressure side pressure, and is difficult to adjust to a high pressure side pressure that provides an optimum COP. Even in the refrigeration cycle apparatus using the refrigeration cycle apparatus, it is possible to efficiently operate the refrigeration cycle apparatus by adjusting the high-pressure side pressure while relaxing the restriction of the constant density ratio by changing the intermediate pressure.

  According to a third aspect of the invention, there is provided discharge temperature detection means for detecting the temperature of the outlet of the compression mechanism, and the opening of the first pressure reducer so that the detection temperature of the discharge temperature detection means becomes a predetermined target discharge temperature. Even if it is a refrigeration cycle apparatus using an expander that is difficult to adjust to the optimum discharge temperature, the density ratio can be changed by changing the intermediate pressure. Efficient operation of the refrigeration cycle apparatus is possible by adjusting the discharge temperature while relaxing certain restrictions.

  According to a fourth aspect of the present invention, there is provided an evaporation temperature detecting means for detecting a temperature at any position between an inlet and an outlet of the evaporator, and an auxiliary compressor suction temperature detecting means for detecting the temperature of the inlet of the auxiliary compression mechanism. And adjusting the opening of the first decompressor so that the difference between the detected temperature of the auxiliary compressor suction temperature detecting means and the detected temperature of the evaporating temperature detecting means becomes a predetermined target superheat degree. 3Equipped with decompressor calculation operation means, even in a refrigeration cycle device using an expander, the degree of superheat of the auxiliary compressor is adjusted while relaxing the restriction of the constant density ratio by changing the intermediate pressure By doing so, efficient operation of the refrigeration cycle apparatus is possible.

  According to a fifth aspect of the present invention, the refrigerant between the gas side outlet of the gas-liquid separator and the inlet of the compression mechanism is bypassed to any position between the inlet of the first decompressor and the inlet of the auxiliary compression mechanism. Even if it is a refrigeration cycle apparatus using an expander with a bypass circuit, the restriction of the constant density ratio is relaxed by changing the mass circulation rate ratio flowing through the auxiliary compression mechanism and the expansion mechanism, and the refrigeration cycle Efficient operation of the device is possible.

  In a sixth aspect of the present invention, the refrigerant between the outlet of the expansion mechanism or auxiliary compression mechanism and the inlet of the gas-liquid separator is either between the liquid-side outlet of the gas-liquid separator and the inlet of the auxiliary compressor. A third bypass circuit is provided to bypass the position of the refrigeration cycle, and even in a refrigeration cycle apparatus using an expander, a constant density ratio is constrained by changing the mass circulation rate ratio flowing through the auxiliary compression mechanism and the expansion mechanism. And the refrigeration cycle apparatus can be operated efficiently.

The seventh invention is provided with a heating means for heating the refrigerant sucked into the compression mechanism. Even in the refrigeration cycle apparatus using the expander, the refrigerant is divided into two flows by the gas-liquid separator, By changing the ratio of the mass circulation rate that flows through each of the expansion mechanism and auxiliary compression mechanism, it is possible to relieve the restriction of a constant density ratio, to obtain a high power recovery effect within a wide operating range, and to be reliable The refrigeration cycle apparatus can be efficiently operated without impairing the performance.

  According to an eighth aspect of the invention, the heating means exchanges heat between the refrigerant between the gas side outlet of the gas-liquid separator and the inlet of the compression mechanism and the refrigerant between the outlet of the radiator and the inlet of the expansion mechanism. Therefore, even in a refrigeration cycle apparatus using an expander, the refrigerant is divided into two flows by the gas-liquid separator, and the ratio of the mass circulation amount flowing through each of the expansion mechanism and the auxiliary compression mechanism is changed. As a result, it is possible to alleviate the restriction of a constant density ratio, to obtain a high power recovery effect within a wide range of operation, and to perform efficient operation of the refrigeration cycle apparatus without impairing reliability.

  According to a ninth aspect of the invention, the heating means is configured to heat the refrigerant between the gas side outlet of the gas-liquid separator and the inlet of the compression mechanism, and even in a refrigeration cycle apparatus using an expander, By dividing the refrigerant into two flows by the gas-liquid separator and changing the ratio of the mass circulation amount that flows through each of the expansion mechanism and the auxiliary compression mechanism, the restriction of the constant density ratio can be relaxed, and within a wide operating range A high power recovery effect can be obtained, and an efficient operation of the refrigeration cycle apparatus can be performed without impairing reliability.

  In the tenth invention, at least the compression mechanism, the expansion mechanism, and the auxiliary compression mechanism are housed and disposed in one sealed container. Even in a refrigeration cycle apparatus using an expander, By dividing the refrigerant into two flows by the liquid separator and changing the ratio of the mass circulation amount that flows through each of the expansion mechanism and auxiliary compression mechanism, the restriction of constant density ratio can be relaxed, and it is high in a wide operating range A power recovery effect can be obtained, and an efficient operation of the refrigeration cycle apparatus can be performed without impairing reliability.

  The eleventh invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. A bypass circuit that bypasses the low pressure side circuit until the pressure is reduced by the pressure reducer and sucked into the auxiliary compression mechanism, and the pressure at any position between the outlet of the compression mechanism and the inlet of the expansion mechanism The heat dissipation The opening of the first pressure reducer is adjusted so that the target high pressure side pressure is predetermined according to the temperature at any position between the outlet of the expansion mechanism and the inlet of the expansion mechanism. Therefore, even in a refrigeration cycle apparatus using an expander that is difficult to adjust to a high pressure side pressure that is an optimal COP, while relaxing the restriction of a constant density ratio by changing the intermediate pressure, By adjusting the high-pressure side pressure, the refrigeration cycle apparatus can be operated efficiently.

  The twelfth invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus including a bypass circuit that is bypassed to a low-pressure side circuit until the pressure is reduced by the pressure reducer and sucked into the auxiliary compression mechanism, the discharge temperature of the compression mechanism is set to a predetermined target discharge temperature. As described above, the opening degree of the first pressure reducer is adjusted, and even if it is a refrigeration cycle apparatus using an expander that is difficult to adjust to an optimum discharge temperature, the intermediate pressure It is possible to operate the refrigeration cycle apparatus efficiently by adjusting the discharge temperature while relaxing the restriction of the constant density ratio by changing.

  The thirteenth invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus comprising a bypass circuit that is bypassed to a low-pressure side circuit from which the pressure is reduced by the pressure reducer until it is sucked into the auxiliary compression mechanism, the suction superheat degree of the auxiliary compression mechanism is a predetermined target superheat degree As described above, the opening degree of the first pressure reducer is adjusted. Even in a refrigeration cycle apparatus using an expander, the restriction of the density ratio is relaxed by changing the intermediate pressure. However, an efficient operation of the refrigeration cycle apparatus is possible by adjusting the degree of superheat of the auxiliary compressor.

  The fourteenth invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus comprising a bypass circuit for bypassing to a low-pressure side circuit until the pressure is reduced by a pressure reducer and sucked into the auxiliary compression mechanism, one of the outlet between the compression mechanism and the expansion mechanism Circulation that flows through the expansion mechanism so that the pressure at the position becomes a target high-pressure side pressure that is predetermined according to the temperature at any position between the outlet of the radiator and the inlet of the expansion mechanism The ratio of the amount and the amount of circulation flowing through the auxiliary compression mechanism is adjusted, and it is a refrigeration cycle apparatus using an expander that is difficult to adjust to a high-pressure side pressure that is an optimal COP. Even in such a case, it is possible to efficiently operate the refrigeration cycle apparatus by adjusting the high-pressure side pressure while relaxing the restriction of the constant density ratio by changing the intermediate pressure.

  The fifteenth aspect of the invention includes at least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus including a bypass circuit that is bypassed to a low-pressure circuit until the pressure is reduced by the pressure reducer and sucked into the auxiliary compression mechanism, the discharge temperature of the compression mechanism becomes a predetermined target discharge temperature. Thus, the ratio of the circulation amount flowing through the expansion mechanism and the circulation amount flowing through the auxiliary compression mechanism is adjusted, and an expander that is difficult to adjust to an optimum discharge temperature is used. Even in the conventional refrigeration cycle apparatus, it is possible to efficiently operate the refrigeration cycle apparatus by adjusting the discharge temperature while relaxing the restriction of the constant density ratio by changing the intermediate pressure.

The sixteenth invention includes at least a compression mechanism for compressing the refrigerant, a radiator for cooling the refrigerant discharged from the compression mechanism, an expansion mechanism for recovering power by reducing the pressure of the refrigerant flowing out of the radiator, An auxiliary compression mechanism that is driven by the recovery power of the expansion mechanism, and a gas that separates the refrigerant that has been decompressed by the expansion mechanism and the intermediate-pressure refrigerant that has been pressurized by the auxiliary compression mechanism into gas refrigerant and liquid refrigerant. A liquid separator; a first pressure reducer that depressurizes the liquid refrigerant flowing out of the gas-liquid separator; an evaporator that evaporates the refrigerant depressurized by the first pressure reducer; and the intermediate pressure refrigerant as the first pressure reducer. In a refrigeration cycle apparatus comprising a bypass circuit that is bypassed to a low-pressure side circuit from which the pressure is reduced by the pressure reducer until it is sucked into the auxiliary compression mechanism, the suction superheat degree of the auxiliary compression mechanism is a predetermined target superheat degree The ratio of the circulation amount flowing through the expansion mechanism and the circulation amount flowing through the auxiliary compression mechanism is adjusted so that the intermediate pressure can be maintained even in a refrigeration cycle apparatus using an expander. It is possible to efficiently operate the refrigeration cycle apparatus by adjusting the superheat degree of the auxiliary compressor while relaxing the restriction of the constant density ratio by changing the value of.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

( Reference Example 1 )
Hereinafter, Reference Example 1 of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing a refrigeration cycle apparatus which is a premise for the control of the present invention. Note that the refrigeration cycle apparatus of this reference example will be described by taking an air conditioner as an example .

The refrigeration cycle apparatus of FIG. 1 has a compression mechanism 11 driven by a drive source (not shown) such as a motor, a radiator 12 that cools the refrigerant discharged from the compression mechanism 11, and decompresses the refrigerant that flows out of the radiator 12. In addition, the expansion mechanism 13 (expansion mechanism) that converts pressure energy into power, the expansion mechanism 13 and the shaft 14 are connected to each other, and the auxiliary compression mechanism 15 that is driven by the recovery power of the expansion mechanism 13 and the expansion mechanism 13 reduce the pressure. After the refrigerant and the refrigerant pressurized by the auxiliary compression mechanism 15 are mixed, the gas-liquid separator 16 that separates into the gas refrigerant and the liquid refrigerant, and the first that depressurizes the liquid refrigerant that flows from the gas-liquid separator 16 to the evaporator 18. A decompressor 17 and an evaporator 18 that absorbs heat by evaporating the refrigerant decompressed by the first decompressor 17 and the like. Carbon dioxide (CO ₂ ) is enclosed as a refrigerant.

  Moreover, the high pressure side pressure detection means 21 for detecting the pressure on the high pressure side (compression mechanism 11 outlet to radiator 12 to expansion mechanism 13 inlet) of the refrigeration cycle apparatus, the temperature between the radiator 12 outlet and the expansion mechanism 13 inlet. A first pressure reducer for calculating and operating the opening of the first pressure reducer 17 by calculating the values detected by the radiator outlet temperature detecting means 22, the high pressure side pressure detecting means 21, and the radiator outlet temperature detecting means 22 to be detected. And an operation device 23.

  In FIG. 1, the solid line arrows indicate the flow of the refrigerant. For the sake of simplicity, the mass circulation amount of the refrigerant flowing through the auxiliary compression mechanism 15 is referred to as G1, and the mass of the refrigerant flowing through the expansion mechanism 13 is described below. The amount of circulation is called G2.

  Next, the operation during normal operation of the refrigeration cycle apparatus configured as described above will be described.

  The compression mechanism 11 compresses the refrigerant to a pressure exceeding the critical pressure (high pressure side pressure). The compressed refrigerant enters a high-temperature and high-pressure state, and is cooled by releasing heat to air or water when flowing through the radiator 12. (At this time, heating or hot water supply can be performed using heated air or water.) Thereafter, the refrigerant is decompressed to an intermediate pressure by the expansion mechanism 13 to be in a gas-liquid two-phase state. The expansion mechanism 13 converts the pressure energy of the refrigerant into power, and the power is transmitted to the shaft 14. After the refrigerant whose pressure has been reduced to the intermediate pressure by the expansion mechanism 13 and the refrigerant whose pressure has been increased to the intermediate pressure by the auxiliary compression mechanism 15 are mixed, the refrigerant flows into the gas-liquid separator 16 through the inlet 161 and is In the liquid separator 16, it is separated into a gas refrigerant and a liquid refrigerant.

The liquid refrigerant separated by the gas-liquid separator 16 flows out from the liquid-side outlet 162, is depressurized to a low temperature and a low pressure (low-pressure side pressure) by the first pressure reducer 17, and again becomes a gas-liquid two-phase state and is supplied to the evaporator 18. The In the evaporator 18, the refrigerant is heated by air or the like. (At this time, cooling can be performed using the cooled air.) Thereafter, the refrigerant enters a gas-liquid two-phase or gas state and is sucked into the auxiliary compression mechanism 15 driven by the shaft 14. On the other hand, the gas refrigerant separated by the gas-liquid separator 16 flows out from the gas side outlet 163 and is sucked into the compression mechanism 11 again.

  In the refrigeration cycle apparatus having such a configuration, the mass circulation amounts flowing through the auxiliary compression mechanism 15 and the expansion mechanism 13 are not the same, and are G1 and G2, respectively. Here, assuming that the volume circulation amount of the refrigerant flowing through the auxiliary compression mechanism 15 is VC, the suction density is DC, the volume circulation amount of the refrigerant flowing through the expansion mechanism 13 is VE, and the suction density is DE, G1 = VC × DC, G2 = VE x DE. When these equations are modified, G1 / G2 = (VC / VE) × (DC / DE) = constant. Since the value of (VC / VE) is a constant determined from the cylinder volume of the expansion mechanism 13 and the auxiliary compression mechanism 15, it can be modified as G1 / G2 = DC / DE = constant. Therefore, if the mass flow rate ratio (G1 / G2) can be changed, the operation can be performed without being constrained by the constant density ratio constraint.

On the other hand, in the refrigeration cycle apparatus of this reference example , assuming that the gas and liquid separator 16 can completely separate the liquid and gas, the dryness of the refrigerant flowing into the gas and liquid separator 16 and the refrigerant before and after the gas and liquid separator 16 Since the mass flow ratio (G1 / G2) is determined by the enthalpy balance, the mass flow ratio cannot be arbitrarily adjusted. However, the actual gas-liquid separator 16 cannot completely separate the liquid and the gas, and is affected by the dryness, the density ratio of the liquid and the gas, etc., and the liquid refrigerant is discharged from the gas side outlet 163. Drops are mixed, or gas is mixed into the liquid refrigerant flowing out from the liquid side outlet 162. Therefore, in practice, the mass flow rate ratio (G1 / G2) can be changed, and the restriction of the constant density ratio can be relaxed.

As described above, in the refrigeration cycle apparatus of the present reference example, even if the refrigeration cycle apparatus using an expander that is difficult to maintain an optimal COP due to a constant density ratio constraint, the gas-liquid separator 16 By dividing the refrigerant into two flows and changing the ratio of the mass circulation amount flowing through each of the expansion mechanism 13 and the auxiliary compression mechanism 15, the restriction of the constant density ratio can be relaxed, and high power can be achieved in a wide operating range. Since a recovery effect can be obtained, an efficient operation of the refrigeration cycle apparatus is possible.

  Next, as a specific method of changing the mass flow rate ratio (G1 / G2), the control of the first pressure reducer 17 will be described based on the flowchart shown in FIG.

  During operation of the refrigeration cycle apparatus, the detected value (heat radiator outlet temperature) (100) from the radiator outlet temperature detecting means 22 is fetched, and the optimum high pressure side pressure corresponding to the fetched radiator outlet temperature is previously stored in the ROM. The selected pressure (hereinafter referred to as a target high-pressure side pressure) is stored in a memory such as a RAM (110). The detection value (high pressure side pressure) from the high pressure side pressure detecting means 21 is taken in (120), and the target high pressure side pressure is compared with the high pressure side pressure taken in (120) (130). When the target high pressure side pressure exceeds the high pressure side pressure, the opening degree of the first pressure reducer 17 is reduced (140). When the target high pressure side pressure is equal to or lower than the high pressure side pressure, the first pressure reducer The opening degree of 17 is increased (150). Then, the process returns to step 100, and thereafter steps 100 to 150 are repeated.

  With respect to the effect of such control, the case where the temperature of the air supplied to the evaporator 18 is reduced (for example, assuming a decrease in indoor load during cooling or a decrease in outside air temperature during heating) is taken as an example in FIG. This will be described with reference to a pressure / enthalpy diagram. When the temperature of the air supplied to the evaporator 18 decreases, the refrigerant temperature (evaporation temperature) of the evaporator 18 decreases, so the refrigerant density at the inlet of the auxiliary compression mechanism 15 decreases and the density ratio (DC / DE) increases. .

  Therefore, if the density ratio does not change due to the restriction of the constant density ratio, the high pressure side pressure is reduced to try to balance with a cycle in which the refrigerant density at the inlet of the expansion mechanism 13 is reduced. (Change from the solid line cycle in FIG. 3 to the one-dot chain line cycle) However, the high pressure side pressure of the cycle that achieves the optimum COP is the same as or higher than the high pressure side pressure before the evaporation pressure decreases. . (Cycle of the two-dot chain line in FIG. 3) That is, the cycle tries to balance in a state where the high-pressure side pressure is lower than the optimum high-pressure side pressure.

However, in this reference example , when the actual high-pressure side pressure is lower than the target high-pressure side pressure, the first pressure reducer 17 is operated in the closing direction, so the low-stage side compression that is the ratio of the low-pressure side pressure to the intermediate pressure The ratio increases and the intermediate pressure increases. When the intermediate pressure changes, as shown in Table 1 below

気液分離器１６での冷媒の液とガスの密度比が小さくなり、気液分離器１６で完全な液とガスとの分離が難しくなる。すなわち、ガス側出口１６３から流出するガス冷媒に液滴が混入すること、あるいは、第一減圧器１７が閉方向に操作されることにより、液側出口１６２から液冷媒が流出しにくくなることにより、質量循環量Ｇ２が増加する。質量循環量Ｇ２が増加すると質量循環量比（Ｇ１／Ｇ２）は小さくなり、Ｇ１／Ｇ２＝ＤＣ／ＤＥ＝一定から密度比（ＤＣ／ＤＥ）も小さくなる。つまり、密度比一定の制約からバランスする高圧側圧力と目標高圧側圧力とのずれが小さくなる。すなわち、密度比一定の制約が緩和される。

The density ratio of the refrigerant liquid and gas in the gas-liquid separator 16 becomes small, and it becomes difficult to completely separate the liquid and gas in the gas-liquid separator 16. That is, when liquid droplets are mixed into the gas refrigerant flowing out from the gas side outlet 163 or the first decompressor 17 is operated in the closing direction, it becomes difficult for the liquid refrigerant to flow out from the liquid side outlet 162. The mass circulation amount G2 increases. When the mass circulation amount G2 increases, the mass circulation amount ratio (G1 / G2) decreases, and the density ratio (DC / DE) also decreases from G1 / G2 = DC / DE = constant. That is, the deviation between the high-pressure side pressure and the target high-pressure side pressure that are balanced due to the constraint of a constant density ratio is reduced. That is, the restriction of a constant density ratio is relaxed.

  Further, since the first pressure reducer 17 is operated in the closing direction and the intermediate pressure increases, even if the compression ratio is substantially fixed by the expansion mechanism 13, the intermediate pressure increases to increase the high-pressure side pressure, Ultimately, it can be adjusted to the target high pressure side pressure.

  Conversely, when the actual high-pressure side pressure is higher than the target high-pressure side pressure, the first decompressor 17 is operated in the opening direction, resulting in a phenomenon reverse to the above description, and the same effect is obtained.

As described above, in the refrigeration cycle apparatus of this reference example , the intermediate pressure can be changed even in a refrigeration cycle apparatus using an expander that is difficult to adjust to the high pressure side pressure that is the optimum COP. Thus, the refrigeration cycle apparatus can be operated efficiently by adjusting the high-pressure side pressure while relaxing the restriction on the constant density ratio.

Although the refrigerant of this reference example has been described as being carbon dioxide, the same effect can be obtained even when the high pressure side during operation exceeds the critical pressure of the refrigerant, such as ethane.

( Reference Example 2 )
A refrigeration cycle apparatus which is a premise relating to the control of the present invention will be described.

FIG. 4 is a configuration diagram showing a refrigeration cycle apparatus in Reference Example 2 . In the configuration diagram of FIG. 4, the same components as those in the reference example 1 of FIG. FIG. 5 is a flowchart showing a control method of the refrigeration cycle apparatus in Reference Example 2 .

The refrigeration cycle apparatus of this reference example calculates the opening of the first pressure reducer 17 based on the value detected by the discharge temperature detecting means 24 and the discharge temperature detecting means 24 for detecting the temperature (discharge temperature) at the outlet of the compression mechanism 11; And a second decompressor operating device 25 to be operated.

  The control of the first pressure reducer 17 will be described based on the flowchart shown in FIG. During the operation of the refrigeration cycle apparatus, the detected value (discharge temperature) (200) from the discharge temperature detecting means 24 is taken in. The target discharge temperature stored in advance in the ROM or the like is compared with the discharge temperature taken in (200) (210). If the target discharge temperature exceeds the discharge temperature, the opening of the first pressure reducer 17 is set. When the target discharge temperature is equal to or lower than the discharge temperature, the opening degree of the first pressure reducer 17 is increased (230). Then, the process returns to Step 200, and thereafter repeats Steps 200 to 230.

  The effect of such control will be described by taking, as an example, the case where the temperature of the air supplied to the evaporator 18 has decreased (for example, assuming a decrease in indoor load during cooling or a decrease in outside air temperature during heating). When the temperature of the air supplied to the evaporator 18 decreases, the refrigerant temperature (evaporation temperature) of the evaporator 18 decreases, so the refrigerant density at the inlet of the auxiliary compression mechanism 15 decreases and the density ratio (DC / DE) increases. . Therefore, if the density ratio does not change due to the restriction of the constant density ratio, the high pressure side pressure is reduced to try to balance the cycle with the refrigerant density at the inlet of the expansion mechanism 13 being reduced, and the discharge temperature is lowered.

However, the high-pressure side pressure in the cycle for achieving the optimum COP is the same as or higher than the high-pressure side pressure before the evaporation pressure is lowered, and the discharge temperature should be increased accordingly. That is, the cycle tries to balance in a state where the discharge temperature is lower than the optimum discharge temperature. However, in this reference example , when the actual discharge temperature is lower than the target discharge temperature, the first pressure reducer 17 is operated in the closing direction, so the low-stage compression ratio that is the ratio of the low-pressure side pressure to the intermediate pressure is The intermediate pressure increases. When the intermediate pressure changes, the liquid refrigerant flows out of the liquid side outlet 162 by mixing the droplets with the gas refrigerant flowing out of the gas side outlet 163 or by operating the first decompressor 17 in the closing direction. By becoming difficult, the mass circulation amount G2 increases. As the mass circulation rate G2 increases, the mass circulation rate ratio (G1 / G2) decreases, and since the density ratio (DC / DE) decreases from G1 / G2 = DC / DE = constant, the constraint on the constant density ratio is relaxed. The

  Further, since the first pressure reducer 17 is operated in the closing direction and the intermediate pressure increases, even if the compression ratio is substantially fixed by the expansion mechanism 13, the intermediate pressure increases to increase the high-pressure side pressure, Accordingly, the discharge temperature also rises, so that it can be finally adjusted to the target discharge temperature.

On the contrary, when the actual discharge temperature is higher than the target discharge temperature, the first decompressor 17 is operated in the opening direction. As a result, a phenomenon reverse to the above description occurs, and the same effect is obtained.

As described above, in the refrigeration cycle apparatus of this reference example , the density ratio is constant by changing the intermediate pressure even in the refrigeration cycle apparatus using an expander that is difficult to adjust to the optimum discharge temperature. Efficient operation of the refrigeration cycle apparatus is possible by adjusting the discharge temperature while relaxing the restrictions.

Although the refrigerant of this reference example has been described as being carbon dioxide, other refrigerants such as R410A can provide the same effect.

( Reference Example 3 )
A refrigeration cycle apparatus which is a premise relating to the control of the present invention will be described.

FIG. 6 is a configuration diagram showing a refrigeration cycle apparatus in Reference Example 3 . In the configuration diagram of FIG. 6, the same components as those of the reference example 1 of FIG. FIG. 7 is a flowchart showing a control method of the refrigeration cycle apparatus in Reference Example 3 .

The refrigeration cycle apparatus of the present reference example detects the temperature between the inlet and outlet of the evaporator 18 (evaporation temperature), and detects the inlet temperature (auxiliary compressor intake temperature) of the auxiliary compression mechanism 15. The superheat degree (auxiliary compressor intake temperature−evaporation temperature) is calculated from the values detected by the auxiliary compressor intake temperature detecting means 27, the evaporation temperature detecting means 26, and the auxiliary compressor intake temperature detecting means 27, and the first is based on the values. And a third decompressor operating device 28 for calculating and operating the opening degree of the decompressor 17.

  The control of the first pressure reducer 17 will be described based on the flowchart shown in FIG. The detection value (evaporation temperature) (300) from the evaporation temperature detection means 26 is taken in, and the detection value (auxiliary compressor suction temperature) (310) from the auxiliary compressor suction temperature detection means 27 is taken in. Calculate the degree of superheat, which is the difference between the intake temperature of the auxiliary compressor and the evaporation temperature, from the captured detection values (320), and compare the target degree of superheat stored in advance in the ROM with the degree of superheat calculated in (320) To do. (330) When the target superheat degree exceeds the superheat degree, the opening degree of the first pressure reducer 17 is reduced (340). When the target superheat degree is equal to or lower than the superheat degree, the first pressure reducer The opening degree of 17 is increased (350). Then, the process returns to step 300, and the subsequent steps 300 to 350 are repeated.

  The effect of such control will be described by taking, as an example, the case where the temperature of the air supplied to the evaporator 18 has decreased (for example, assuming a decrease in indoor load during cooling or a decrease in outside air temperature during heating). When the temperature of the air supplied to the evaporator 18 decreases, the refrigerant temperature (evaporation temperature) of the evaporator 18 decreases, so the refrigerant density at the inlet of the auxiliary compression mechanism 15 decreases and the density ratio (DC / DE) increases. . Therefore, if the density ratio does not change due to the restriction of the constant density ratio, the cycle tries to balance in a state where the high-pressure side pressure is lower than the optimum high-pressure side pressure.

  As a result, the amount of refrigerant held in the high-pressure side circuit (compression mechanism 11 outlet to radiator 12 to expansion mechanism 13 inlet) decreases, so the low-pressure side circuit (first decompressor 17 outlet to evaporator 18 to auxiliary compression). The amount of refrigerant to be held at the mechanism 15 inlet) increases, and the (intake) superheat degree of the auxiliary compression mechanism 15 decreases. However, in the present embodiment, when the actual superheat degree is lower than the target superheat degree, the first pressure reducer 17 is operated in the closing direction, so that the low stage side compression ratio, which is the ratio between the low pressure side pressure and the intermediate pressure. Increases and the intermediate pressure increases.

When the intermediate pressure changes, liquid droplets are unlikely to flow out from the liquid side outlet 162 due to mixing of liquid droplets with the gas refrigerant flowing out from the gas side outlet 163 or operating the first decompressor 17 in the closing direction. As a result, the mass circulation amount G2 increases. As the mass circulation rate G2 increases, the mass circulation rate ratio (G1 / G2) decreases, and since the density ratio (DC / DE) decreases from G1 / G2 = DC / DE = constant, the constraint on the constant density ratio is relaxed. The Further, since the first pressure reducer 17 is operated in the closing direction and the intermediate pressure increases, even if the compression ratio is substantially fixed by the expansion mechanism 13, the intermediate pressure increases to increase the high-pressure side pressure, Since the amount of refrigerant held in the high-pressure side circuit increases, the amount of refrigerant held in the low-pressure side circuit decreases and the (intake) superheat degree of the auxiliary compression mechanism 15 increases. Can be adjusted at any time.

  Conversely, when the actual degree of superheat is higher than the target degree of superheat, the first decompressor 17 is operated in the opening direction, resulting in a phenomenon opposite to that described above, and a similar effect is obtained.

As described above, in the refrigeration cycle apparatus of this reference example, even if the refrigeration cycle apparatus using an expander is used, the auxiliary compressor is overheated while relaxing the constant density ratio constraint by changing the intermediate pressure. By adjusting the degree, the refrigeration cycle apparatus can be operated efficiently.

Although the refrigerant of this reference example has been described as being carbon dioxide, other refrigerants such as R410A can provide the same effect.

( Embodiment 1 )
A refrigeration cycle apparatus according to a first embodiment of the present invention will be described. The present invention is not limited to the air conditioner of the present embodiment, and may be a hot water supply device or the like.

FIG. 8 is a configuration diagram showing the refrigeration cycle apparatus according to the first embodiment of the present invention. In the configuration diagram of FIG. 8, the same components as those in the reference example 1 of FIG.

  The refrigeration cycle apparatus of the present embodiment includes a first bypass circuit 31 and a first bypass that bypass the refrigerant between the gas side outlet 163 of the gas-liquid separator 16 and the inlet of the compression mechanism 11 to the inlet of the auxiliary compression mechanism 15. And a first electromagnetic valve 32 that controls whether or not the refrigerant flows through the circuit 31.

  About the operation | movement at the time of normal driving | operation of a refrigerating-cycle apparatus, and the control method of the 1st pressure reduction device 17, since it is the same as that of 1st to 3rd Embodiment, description is abbreviate | omitted and it is the added component 1st. The operation of the electromagnetic valve 32 will be described.

  When the high pressure side pressure and discharge temperature and the (compression) superheat degree of the auxiliary compression mechanism 15 are high and cannot be adjusted to the target high pressure side pressure, discharge temperature and superheat degree by the control of the first pressure reducer 17, the first electromagnetic The valve 32 is controlled to be opened, and the gas separated by the gas-liquid separator 16 is bypassed to the low pressure side circuit. As a result, the mass circulation rate G1 increases and the mass circulation rate G2 decreases, so that the mass circulation rate ratio (G1 / G2) increases and G1 / G2 = DC / DE = constant to density ratio (DC / DE). Also grows. That is, it is possible to reduce the high-pressure side pressure balanced from the restriction of the constant density ratio and the discharge temperature corresponding thereto. (By reducing the high-pressure side pressure, the refrigerant density at the inlet of the expansion mechanism 13 is reduced.) Therefore, in the refrigeration cycle apparatus of the present embodiment, even if the refrigeration cycle apparatus using an expander is used, the auxiliary By changing the mass circulation rate ratio flowing through the compression mechanism 15 and the expansion mechanism 13, the restriction of the constant density ratio is relaxed, and the refrigeration cycle apparatus can be operated efficiently.

In the description of the present embodiment, it has been described that the first electromagnetic valve 32 is operated when the first pressure reducer 17 cannot adjust, but a factor that greatly changes the cycle state, for example, switching between heating and cooling, load The first solenoid valve 32 may be operated according to changes in the outside air temperature.

  In addition, the first bypass circuit 31 is described as bypassing the inlet of the auxiliary compression mechanism 15 from the viewpoint of efficient use of the evaporator, but any one between the inlet of the first pressure reducer 17 and the inlet of the auxiliary compression mechanism 15 may be used. The same effect can be obtained even if it is bypassed. The first solenoid valve 32 may be an expansion valve capable of adjusting the flow rate, and the first pressure reducer 17 may be a capillary tube as a fixed throttle means. The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

( Reference Example 4 )
A refrigeration cycle apparatus in Reference Example 4 of the present invention will be described.

FIG. 9 is a block diagram showing a refrigeration cycle apparatus in Reference Example 4 of the present invention. In the configuration diagram of FIG. 9, the same components as those in the reference example 1 of FIG.

In the refrigeration cycle apparatus of this reference example, the refrigerant between the liquid side outlet 162 of the gas-liquid separator 16 and the inlet of the first decompressor 17 is exchanged between the gas side outlet 163 of the gas-liquid separator 16 and the inlet of the compression mechanism 11. A second bypass circuit 33 that bypasses the second bypass circuit 33, a second electromagnetic valve 34 that controls whether or not the refrigerant flows through the second bypass circuit 33, and a gas-side outlet 163 side to a liquid-side outlet 162 side of the gas-liquid separator 16 A check valve 35 for preventing the refrigerant from flowing back through the second bypass circuit 33 is provided.

  Since the operation of the refrigeration cycle apparatus during normal operation and the control method of the first pressure reducer 17 are the same as those in the first to third embodiments, the description is omitted and a second component which is an added component is omitted. The operation of the electromagnetic valve 33 will be described.

  When the high pressure side pressure and discharge temperature and the (intake) superheat degree of the auxiliary compression mechanism 15 are low and cannot be adjusted to the target high pressure side pressure, discharge temperature and superheat degree by the control of the first pressure reducer 17, the second electromagnetic The valve 33 is controlled to be opened, and the liquid separated by the gas-liquid separator 16 is bypassed to the high-pressure side circuit. As a result, the mass circulation amount G2 increases and the mass circulation amount G1 decreases, so the mass circulation amount ratio (G1 / G2) decreases, and G1 / G2 = DC / DE = constant to density ratio (DC / DE). Becomes smaller. That is, it is possible to increase the high-pressure side pressure balanced from the restriction of a constant density ratio and the discharge temperature corresponding thereto. (By increasing the high-pressure side pressure, the refrigerant density at the inlet of the expansion mechanism 13 is increased.) Therefore, in the refrigeration cycle apparatus of the embodiment of the present reference example, even if the refrigeration cycle apparatus using an expander, By changing the mass circulation rate ratio flowing through the auxiliary compression mechanism 15 and the expansion mechanism 13, the restriction of the constant density ratio can be relaxed, and the refrigeration cycle apparatus can be operated efficiently.

  In the description of the present reference example, it has been described that the second electromagnetic valve 34 is operated when the first pressure reducer 17 cannot be adjusted. However, factors that greatly change the state of the cycle, such as switching between heating and cooling, load, The second solenoid valve 34 may be operated according to changes in the outside air temperature. The second electromagnetic valve 34 may be an expansion valve capable of adjusting the flow rate, and the first pressure reducer 17 may be a capillary tube as a fixed throttle means. The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

( Embodiment 2 )
A refrigeration cycle apparatus according to the second embodiment of the present invention will be described. The present invention is not limited to the air conditioner of the present embodiment, and may be a hot water supply device or the like.

FIG. 10 is a block diagram showing a refrigeration cycle apparatus according to the second embodiment of the present invention. In the configuration diagram of FIG. 10, the same components as those in the reference example 1 of FIG.

The refrigeration cycle apparatus of the present embodiment has a third bypass circuit 41 that bypasses the refrigerant between the outlet of the expansion mechanism 13 or auxiliary compression mechanism 15 and the inlet 161 of the gas-liquid separator 16 to the inlet of the evaporator 18. And a second decompressor 42 that adjusts the mass circulation amount flowing in the third bypass circuit 41. Further, the first pressure reducer 17 in Reference Example 1 of FIG. 1 is changed to a capillary tube 40.

The operation of the refrigeration cycle apparatus during normal operation is the same as in Reference Examples 1 to 3, and the control method of the second pressure reducer 42 is the control of the first pressure reducer 17 in Reference Examples 1 to 3 . Since it is the same as the method, the description will be simplified. For example, when the high pressure side pressure is higher than the optimum high pressure side pressure, the second decompressor 42 is controlled in the opening direction in the present embodiment, The refrigerant flowing into the gas-liquid separator 16 is bypassed to the low pressure side circuit.

  As a result, the mass circulation rate G1 increases and the mass circulation rate G2 decreases, so that the mass circulation rate ratio (G1 / G2) increases and G1 / G2 = DC / DE = constant to density ratio (DC / DE). Also grows. That is, it is possible to reduce the high-pressure side pressure that is balanced from the constraint of a constant density ratio. (By reducing the high-pressure side pressure, the refrigerant density at the inlet of the expansion mechanism 13 is reduced.) Therefore, in the refrigeration cycle apparatus of the present embodiment, even if the refrigeration cycle apparatus using an expander is used, the auxiliary By changing the mass circulation rate ratio flowing through the compression mechanism 15 and the expansion mechanism 13, the restriction of the constant density ratio is relaxed, and the refrigeration cycle apparatus can be operated efficiently.

  Instead of the capillary tube 40, the first pressure reducer 17 may be used as in the first embodiment. The third bypass circuit 41 has been described as bypassing to the evaporator 18 inlet, but the same effect can be obtained by bypassing to any one between the capillary tube 40 inlet and the auxiliary compression mechanism 15 inlet. The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

( Reference Example 5 )
A refrigeration cycle apparatus in Reference Example 5 of the present invention will be described.

FIG. 11 is a block diagram showing a refrigeration cycle apparatus in Reference Example 5 of the present invention. In the configuration diagram of FIG. 11, the same components as those in the reference example 1 of FIG.

In the refrigeration cycle apparatus of the present reference example, the refrigerant between the outlet of the expansion mechanism 13 or the auxiliary compression mechanism 15 and the inlet 161 of the gas-liquid separator 16 is exchanged with the gas-side outlet 163 of the gas-liquid separator 16 and the compression mechanism 11. A fourth bypass circuit 43 that bypasses to the inlet and a third decompressor 44 that adjusts the amount of mass circulation flowing through the fourth bypass circuit 43 are provided. Further, the first pressure reducer 17 in Reference Example 1 of FIG. 1 is changed to a capillary tube 40.

The operation of the refrigeration cycle apparatus during normal operation is the same as in Reference Examples 1 to 3, and the control method of the third pressure reducer 44 is the control of the first pressure reducer 17 in Reference Examples 1 to 3 . Since this is the same as the method, the description will be simplified. For example, when the high-pressure side pressure is lower than the optimum high-pressure side pressure, the third decompressor 44 is controlled in the opening direction in this reference example, The refrigerant flowing into the liquid separator 16 is bypassed to the high pressure side circuit.

As a result, the mass circulation amount G2 increases and the mass circulation amount G1 decreases, so the mass circulation amount ratio (G1 / G2) decreases, and G1 / G2 = DC / DE = constant to density ratio (DC / DE). Becomes smaller. That is, it is possible to increase the high-pressure side pressure that is balanced due to the constraint of a constant density ratio. (By increasing the high-pressure side pressure, the refrigerant density at the inlet of the expansion mechanism 13 is increased.) Therefore, in the refrigeration cycle apparatus of this reference example, even if the refrigeration cycle apparatus using an expander is used, auxiliary compression is performed. By changing the mass circulation rate ratio flowing through the mechanism 15 and the expansion mechanism 13, the restriction of the constant density ratio is relaxed, and the refrigeration cycle apparatus can be operated efficiently.

Instead of the capillary tube 40, the first pressure reducer 17 may be used as in Reference Example 1 . The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

(Reference Example 6)
A refrigeration cycle apparatus in Reference Example 6 of the present invention will be described.

FIG. 12 is a block diagram showing a refrigeration cycle apparatus in Reference Example 6 of the present invention. In the configuration diagram of FIG. 12, the same components as those in Reference Example 1 of FIG.

The refrigeration cycle apparatus of the present reference example has a mass circulation amount flowing through the fifth bypass circuit 51 and the fifth bypass circuit 51 that bypasses the refrigerant between the radiator 12 outlet and the expansion mechanism 13 inlet to the evaporator 18 inlet. And a fourth decompressor 52 to be adjusted. Further, the first pressure reducer 17 in Reference Example 1 of FIG. 1 is changed to a capillary tube 40.

The operation of the refrigeration cycle apparatus during normal operation is the same as in Reference Examples 1 to 3, and the control method of the fourth decompressor 52 is the control of the first decompressor 17 in Reference Examples 1 to 3 . Since this is the same as the method, the description will be simplified. For example, when the high-pressure side pressure is higher than the optimum high-pressure side pressure, the fourth decompressor 52 is controlled in the opening direction in this reference example to expand the pressure. The refrigerant flowing into the mechanism 13 is bypassed to the low pressure side circuit.

  As a result, the mass circulation rate G1 increases and the mass circulation rate G2 decreases, so that the mass circulation rate ratio (G1 / G2) increases and G1 / G2 = DC / DE = constant to density ratio (DC / DE). Also grows. That is, it is possible to reduce the high-pressure side pressure that is balanced from the constraint of a constant density ratio. (By reducing the high-pressure side pressure, the refrigerant density at the inlet of the expansion mechanism 13 is reduced.) Therefore, in the refrigeration cycle apparatus of this reference example, even if the refrigeration cycle apparatus using an expander is used, auxiliary compression is performed. By changing the mass circulation rate ratio flowing through the mechanism 15 and the expansion mechanism 13, the restriction of the constant density ratio is relaxed, and the refrigeration cycle apparatus can be operated efficiently.

Instead of the capillary tube 40, the first pressure reducer 17 may be used as in Reference Example 1 . The fifth bypass circuit 51 has been described as bypassing to the inlet of the evaporator 18, but the same effect can be obtained by bypassing to any one between the inlet of the capillary tube 40 and the inlet of the auxiliary compression mechanism 15. The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

( Reference Example 7 )
A refrigeration cycle apparatus in Reference Example 7 of the present invention will be described.

FIG. 13 is a block diagram showing a refrigeration cycle apparatus in Reference Example 7 of the present invention. In the configuration diagram of FIG. 13, the same components as those in Reference Example 1 of FIG.

The refrigeration cycle apparatus according to the present reference example bypasses the refrigerant between the outlet of the radiator 12 and the inlet of the expansion mechanism 13 between the gas side outlet 163 of the gas-liquid separator 16 and the inlet of the compression mechanism 11. And a fifth decompressor 54 that adjusts the mass circulation amount flowing in the circuit 53 and the sixth bypass circuit 53. Further, the first pressure reducer 17 in Reference Example 1 of FIG. 1 is changed to a capillary tube 40.

The operation during normal operation of the refrigeration cycle apparatus is the same as in Reference Examples 1 to 3, and the control method of the fifth decompressor 54 is the control of the first decompressor 17 in Reference Examples 1 to 3 . Since this is the same as the method, the description will be simplified. For example, when the high-pressure side pressure is lower than the optimum high-pressure side pressure, the fifth decompressor 54 is controlled in the opening direction in this reference example to expand The refrigerant flowing into the mechanism 13 is bypassed to the high-pressure side circuit.

  As a result, the mass circulation amount G2 increases and the mass circulation amount G1 decreases, so the mass circulation amount ratio (G1 / G2) decreases, and G1 / G2 = DC / DE = constant to density ratio (DC / DE). Becomes smaller. That is, it is possible to increase the high-pressure side pressure that is balanced due to the constraint of a constant density ratio. (By increasing the high-pressure side pressure, the refrigerant density at the inlet of the expansion mechanism 13 is increased.) Therefore, in the refrigeration cycle apparatus of this reference example, even if the refrigeration cycle apparatus using an expander is used, auxiliary compression is performed. By changing the mass circulation rate ratio flowing through the mechanism 15 and the expansion mechanism 13, the restriction of the constant density ratio is relaxed, and the refrigeration cycle apparatus can be operated efficiently.

Instead of the capillary tube 40, the first pressure reducer 17 may be used as in Reference Example 1 . The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

( Reference Example 8 )
A refrigeration cycle apparatus in Reference Example 8 of the present invention will be described.

FIG. 14 is a configuration diagram showing a refrigeration cycle apparatus in Reference Example 8 of the present invention. In the configuration diagram of FIG. 14, the same components as those in the reference example 1 of FIG.

In the refrigeration cycle apparatus of this reference example, the refrigerant between the outlet of the radiator 12 and the inlet of the expansion mechanism 13 is passed between the outlet of the expansion mechanism 13 or the auxiliary compression mechanism 15 and the inlet 161 of the gas-liquid separator 16. A seventh bypass circuit 55 for bypassing, and a sixth pressure reducer 56 for adjusting a mass circulation amount flowing in the seventh bypass circuit 55. Further, the first pressure reducer 17 in Reference Example 1 of FIG. 1 is changed to a capillary tube 40.

The operation of the refrigeration cycle apparatus during normal operation is the same as in Reference Examples 1 to 3, and the control method of the sixth pressure reducer 56 is the control of the first pressure reducer 17 in Reference Examples 1 to 3 . Since this is the same as the method, the description will be simplified. For example, when the high-pressure side pressure is higher than the optimum high-pressure side pressure, the sixth decompressor 56 is controlled in the opening direction in this reference example to expand The refrigerant flowing into the mechanism 13 is bypassed to a circuit having an intermediate pressure.

As a result, the mass circulation rate G2 decreases, so the mass circulation rate ratio (G1 / G2) increases, and the density ratio (DC / DE) also increases from G1 / G2 = DC / DE = constant. That is, it is possible to reduce the high-pressure side pressure that is balanced from the constraint of a constant density ratio. (By decreasing the high-pressure side pressure, an attempt is made to reduce the refrigerant density at the inlet of the expansion mechanism 13).
In the refrigeration cycle apparatus of this reference example, even in a refrigeration cycle apparatus using an expander, the restriction of the constant density ratio is relaxed by changing the mass circulation rate ratio flowing through the auxiliary compression mechanism 15 and the expansion mechanism 13, Efficient operation of the refrigeration cycle apparatus is possible.

Instead of the capillary tube 40, the first pressure reducer 17 may be used as in Reference Example 1 . The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

( Reference Example 9 )
A refrigeration cycle apparatus in Reference Example 9 of the present invention will be described.

FIG. 15 is a configuration diagram showing a refrigeration cycle apparatus in Reference Example 9 . In the configuration diagram of FIG. 15, the same components as those in the reference example 1 of FIG.

In the refrigeration cycle apparatus of Reference Example 9 in FIG. 15, the components different from Reference Example 1 in FIG. 1 are a capillary tube 40 instead of the first pressure reducer 17 and a gas-liquid with a flow rate adjusting valve instead of the gas-liquid separator 16. Separator 60. As shown in FIG. 16, the gas-liquid separator 60 with a flow rate adjusting valve penetrates through the bottom of the gas-liquid separation container 61 and the two-phase refrigerant pipe 62 inserted so as to penetrate from the top to the bottom of the gas-liquid separation container 61. The gas refrigerant pipe 63 reaching the upper part of the inside of the container is a main component.

  The two-phase refrigerant pipe 62 is provided with a branch pipe 64 through a flow rate adjusting valve 65 for allowing a part of the refrigerant flowing in the pipe to flow out into the gas-liquid separation container 61. Further, the two-phase refrigerant pipe 62 is also provided with a liquid return hole 66 for returning the liquid refrigerant staying at the bottom of the gas-liquid separation container 61 into the two-phase refrigerant pipe 62.

  When the flow rate adjustment valve 65 is fully closed, the gas-liquid separator 60 with a flow rate adjustment valve has a high dryness two-phase refrigerant flowing from the inlet 610 of the gas-liquid separator 60 with a flow rate adjustment valve. It flows out of the liquid side outlet 602 through the two-phase refrigerant pipe 62. When the flow rate adjustment valve 65 is operated in the opening direction, a part of the two-phase refrigerant flowing through the two-phase refrigerant pipe 62 flows into the gas-liquid separation container 61 and is separated into liquid refrigerant and gas refrigerant in the container. .

  The low-density gas refrigerant flows from the upper part of the container through the gas refrigerant pipe 63 and flows out from the gas-side outlet 603, and the high-density liquid refrigerant stays at the bottom of the container and then enters the two-phase refrigerant pipe 62 from the liquid return hole 66 again. It returns and flows out from the liquid side outlet 602 as a two-phase refrigerant having a low dryness together with the two-phase refrigerant that has not flowed into the container. That is, the amount of mass circulation flowing out from the liquid side outlet 602 and the gas side outlet 603 can be varied by adjusting the opening degree of the flow rate adjusting valve 65.

The operation during normal operation of the refrigeration cycle apparatus is the same as in Reference Examples 1 to 3, and the control method of the flow rate adjusting valve 64 is the control method of the first pressure reducer 17 in Reference Examples 1 to 3 . However, for example, when the high-pressure side pressure is lower than the optimum high-pressure side pressure, the flow rate adjusting valve 64 is controlled in the opening direction in this reference example, and the inlet 601 is used. The two-phase refrigerant that flows in from the gas flows out into the gas-liquid separation container 61, and the mass circulation amount of the refrigerant that flows out from the gas side outlet 603 is increased.

As a result, the mass circulation amount G2 increases and the mass circulation amount G1 decreases, so the mass circulation amount ratio (G1 / G2) decreases, and G1 / G2 = DC / DE = constant to density ratio (DC / DE). Becomes smaller. That is, it is possible to increase the high-pressure side pressure that is balanced due to the constraint of a constant density ratio. (By increasing the high-pressure side pressure, the refrigerant density at the inlet of the expansion mechanism 13 is increased.) Therefore, in the refrigeration cycle apparatus of this reference example, even if the refrigeration cycle apparatus using an expander is used, auxiliary compression is performed. By changing the mass circulation rate ratio flowing through the mechanism 15 and the expansion mechanism 13, the restriction of the constant density ratio is relaxed, and the refrigeration cycle apparatus can be operated efficiently.

Instead of the capillary tube 40, the first pressure reducer 17 may be used as in Reference Example 1 . Further, the gas-liquid separator 60 with the flow rate adjusting valve may be configured to vary the mass circulation amount flowing out from the liquid side outlet 602 and the gas side outlet 603 using a three-way valve or the like instead of the flow rate adjusting valve 65. good. Also, the two-phase refrigerant pipe 62 returns to the two-phase refrigerant pipe 62 the oil staying at the bottom of the gas-liquid separation container 61 among the lubricating oil discharged from the compression mechanism 11 and the auxiliary compressor 13. Alternatively, a lubricating oil return hole for returning to the auxiliary compression mechanism 15 may be provided. The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

( Reference Example 10 )
A refrigeration cycle apparatus in Reference Example 10 of the present invention will be described.

FIG. 17 is a configuration diagram showing a refrigeration cycle apparatus which is a premise regarding the configuration for heating the refrigerant sucked into the compression mechanism . In the configuration diagram of FIG. 17, the same components as those in the reference example 1 of FIG.

In the refrigeration cycle apparatus of the present embodiment in FIG. 17, the difference from the reference example 1 in FIG. 1 is from the refrigerant between the gas side outlet 163 of the gas-liquid separator 16 and the inlet of the compression mechanism 11 and the outlet of the radiator 12. The internal heat exchanger 70 for exchanging heat with the refrigerant up to the inlet of the expansion mechanism 13 is provided, a drive source (not shown) for driving the compression mechanism 11, the compression mechanism 11, the expansion mechanism 13, and the auxiliary The compression mechanism 15 is housed in one sealed container 80.

Since the operation and control method during normal operation of the refrigeration cycle apparatus are the same as the control method of the first pressure reducer 17 in Reference Examples 1 to 3 , description thereof will be omitted.

  By providing the internal heat exchanger 70, the refrigerant sucked into the compression mechanism 11 can be obtained even if liquid droplets are mixed into the refrigerant flowing out from the gas side outlet 163 of the gas-liquid separator 16 by the control of the first decompressor 17. Since it is heated by the internal heat exchanger, the risk of liquid compression in the compression mechanism 11 is avoided, and the reliability of the compression mechanism 11 is improved.

  In addition, by storing the compression mechanism 11, the expansion mechanism 13, and the auxiliary compression mechanism 15 in the sealed container 80, each mechanism can be properly lubricated without biasing the lubricating oil that lubricates these mechanisms. Reliability is improved.

Therefore, in the refrigeration cycle apparatus of this reference example, even in the refrigeration cycle apparatus using an expander, the refrigerant is divided into two flows by the gas-liquid separator 16, and each of the expansion mechanism 13 and the auxiliary compression mechanism 15 is separated. By changing the ratio of the circulating mass flow rate, the constant density ratio constraint can be relaxed, a high power recovery effect can be obtained within a wide operating range, and the efficiency of the refrigeration cycle system without compromising reliability A good driving is possible.

The internal heat exchanger 70 described in this reference example is an example of a heating unit that heats the refrigerant sucked into the compression mechanism 11, and as another heating unit, compression is performed from the gas side outlet 163 of the gas-liquid separator 16. Heat may be exchanged between the refrigerant up to the mechanism 11 inlet and air or water, or may be heated by a heater. The same effect can be obtained by using a refrigerant other than carbon dioxide, such as R410A.

In all of the first to second embodiments described above, a four-way valve or the like is added to reverse the flow of the refrigerant, thereby switching between the evaporator and the radiator and cooling (cooling side). It is good also as a heat pump refrigerating cycle device which can be used by switching between utilization) and heating (utilization on the heating side).

  The refrigeration cycle apparatus and its control method of the present invention are useful for a hot water supply apparatus (hot water heater), a home air conditioner, a vehicle air conditioner (car air conditioner), and the like.

The block diagram which shows the refrigerating-cycle apparatus in the reference example 1 of this invention. A flowchart showing a control method of the refrigeration cycle apparatus Pressure and enthalpy diagram showing changes in the refrigeration cycle The block diagram which shows the refrigerating-cycle apparatus in the reference example 2 of this invention. A flowchart showing a control method of the refrigeration cycle apparatus The block diagram which shows the refrigerating-cycle apparatus in the reference example 3 of this invention. A flowchart showing a control method of the refrigeration cycle apparatus The block diagram which shows the refrigerating-cycle apparatus in the 1st Embodiment of this invention. The block diagram which shows the refrigerating-cycle apparatus in the reference example 4 of this invention. The block diagram which shows the refrigerating-cycle apparatus in the 2nd Embodiment of this invention. The block diagram which shows the refrigerating-cycle apparatus in the reference example 5 of this invention. The block diagram which shows the refrigerating-cycle apparatus in the reference example 6 of this invention. The block diagram which shows the refrigerating-cycle apparatus in the reference example 7 of this invention. The block diagram which shows the refrigerating-cycle apparatus in the reference example 8 of this invention. The block diagram which shows the refrigerating-cycle apparatus in the reference example 9 of this invention. The block diagram which shows the gas-liquid separator with a flow regulating valve in the reference example 9 of this invention The block diagram which shows the refrigerating-cycle apparatus in the reference example 10 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Compression mechanism 12 Radiator 13 Expansion mechanism 15 Auxiliary compression mechanism 16 Gas-liquid separator 17 1st pressure reduction device 18 Evaporator 21 High pressure side pressure detection means 22 Radiator outlet temperature detection means 23 1st pressure reduction device arithmetic operation device 24 Discharge temperature Detection means 25 Second decompressor arithmetic operation unit 26 Evaporation temperature detection unit 27 Auxiliary compressor intake temperature detection unit 28 Third decompressor arithmetic operation unit 31 First bypass circuit 33 Second bypass circuit 41 Third bypass circuit 42 Second decompression Unit 43 fourth bypass circuit 44 third decompressor 51 fifth bypass circuit 52 fourth decompressor 53 sixth bypass circuit 54 fifth decompressor 55 seventh bypass circuit 56 sixth decompressor 60 gas-liquid separator with flow regulating valve 65 Flow control valve 70 Internal heat exchanger 80 Airtight container

Claims (16)

At least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the heat radiator, and recovery power of the expansion mechanism An auxiliary compression mechanism to be driven; an expansion mechanism; a gas-liquid separator communicating with the auxiliary compression mechanism; a first decompressor that decompresses liquid refrigerant flowing out from the gas-liquid separator; and the first decompressor. An evaporator for evaporating the decompressed refrigerant, and the intermediate-pressure refrigerant, which is the refrigerant decompressed by the expansion mechanism and the refrigerant pressurized by the auxiliary compression mechanism, is gas and liquid refrigerant in the gas-liquid separator. And a bypass circuit configured to bypass the intermediate-pressure refrigerant to a low-pressure side circuit until the refrigerant is decompressed by the first decompressor and sucked into the auxiliary compression mechanism. High pressure side pressure detecting means for detecting pressure at any position between the outlet of the compression mechanism and the inlet of the expansion mechanism; and at any position between the outlet of the radiator and the inlet of the expansion mechanism. A radiator outlet temperature detecting means for detecting the temperature, so that the pressure detected by the high pressure side pressure detecting means becomes a target high pressure side pressure predetermined according to the detected temperature of the radiator outlet temperature detecting means. The refrigeration cycle apparatus according to claim 1, further comprising first decompressor calculation operation means for adjusting an opening degree of the first decompressor. Discharge temperature detection means for detecting the temperature of the outlet of the compression mechanism, and a second pressure reduction that adjusts the opening of the first pressure reducer so that the detected temperature of the discharge temperature detection means becomes a predetermined target discharge temperature. The refrigeration cycle apparatus according to claim 1, further comprising a storage unit operation means. The auxiliary compressor comprising: an evaporation temperature detecting means for detecting a temperature at any position between the inlet and the outlet of the evaporator; and an auxiliary compressor suction temperature detecting means for detecting the temperature of the inlet of the auxiliary compression mechanism. Third decompressor calculation operation means for adjusting the opening degree of the first decompressor so that the difference between the detected temperature of the suction temperature detecting means and the detected temperature of the evaporation temperature detecting means becomes a predetermined target superheat degree. The refrigeration cycle apparatus according to claim 1, further comprising: A first bypass circuit is provided for bypassing the refrigerant between the gas side outlet of the gas-liquid separator and the inlet of the compression mechanism to any position between the inlet of the first pressure reducer and the inlet of the auxiliary compression mechanism. Claim 1
The refrigeration cycle apparatus described. The refrigerant between the outlet of the expansion mechanism or auxiliary compression mechanism and the inlet of the gas-liquid separator is bypassed to any position between the liquid-side outlet of the gas-liquid separator and the inlet of the auxiliary compressor. The refrigeration cycle apparatus according to claim 1, further comprising a three bypass circuit. The refrigeration cycle apparatus according to claim 1, further comprising heating means for heating the refrigerant sucked into the compression mechanism. The heating means is configured to exchange heat between the refrigerant between the gas side outlet of the gas-liquid separator and the inlet of the compression mechanism and the refrigerant between the outlet of the radiator and the inlet of the expansion mechanism. Refrigeration cycle equipment. The refrigeration cycle apparatus according to claim 7, wherein the heating means is configured to heat the refrigerant between the gas side outlet of the gas-liquid separator and the inlet of the compression mechanism. The refrigeration cycle apparatus according to any one of claims 1 to 9, wherein at least the compression mechanism, the expansion mechanism, and the auxiliary compression mechanism are housed and disposed in one sealed container. At least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the heat radiator, and recovery power of the expansion mechanism An auxiliary compression mechanism that is driven, a gas-liquid separator that separates a refrigerant having an intermediate pressure, which is a refrigerant decompressed by the expansion mechanism and a refrigerant that has been pressurized by the auxiliary compression mechanism, into a gas refrigerant and a liquid refrigerant; A first decompressor for decompressing the liquid refrigerant flowing out from the gas-liquid separator; an evaporator for evaporating the refrigerant decompressed by the first decompressor; and the intermediate pressure refrigerant being decompressed by the first decompressor, In the refrigeration cycle apparatus including a bypass circuit that bypasses the low-pressure side circuit until the auxiliary compression mechanism is sucked, the pressure at any position between the outlet of the compression mechanism and the inlet of the expansion mechanism is Adjusting the opening of the first pressure reducer so that a target high-pressure side pressure is predetermined according to the temperature at any position between the outlet of the radiator and the inlet of the expansion mechanism. A control method for a refrigeration cycle apparatus. At least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the heat radiator, and recovery power of the expansion mechanism An auxiliary compression mechanism that is driven, a gas-liquid separator that separates a refrigerant having a reduced pressure by the expansion mechanism and a medium-pressure refrigerant that is a pressure increased by the auxiliary compression mechanism into a gas refrigerant and a liquid refrigerant, and the gas A first decompressor for decompressing the liquid refrigerant flowing out from the liquid separator; an evaporator for evaporating the refrigerant decompressed by the first decompressor; and the intermediate pressure refrigerant being decompressed by the first decompressor and the auxiliary In the refrigeration cycle apparatus including a bypass circuit that bypasses the low-pressure circuit until it is sucked into the compression mechanism, the discharge temperature of the compression mechanism is set to a predetermined target discharge temperature. The method of the refrigeration cycle apparatus characterized by adjusting the opening of the decompressor. At least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the heat radiator, and recovery power of the expansion mechanism An auxiliary compression mechanism that is driven, a gas-liquid separator that separates a refrigerant having a reduced pressure by the expansion mechanism and a medium-pressure refrigerant that is a pressure increased by the auxiliary compression mechanism into a gas refrigerant and a liquid refrigerant, and the gas A first decompressor for decompressing the liquid refrigerant flowing out from the liquid separator; an evaporator for evaporating the refrigerant decompressed by the first decompressor; and the intermediate pressure refrigerant being decompressed by the first decompressor and the auxiliary In a refrigeration cycle apparatus comprising a bypass circuit for bypassing to a low-pressure side circuit until being sucked into the compression mechanism, the suction superheat degree of the auxiliary compression mechanism is set to a predetermined target superheat degree. The method of the refrigeration cycle apparatus characterized by adjusting the opening of one pressure reducer. At least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the heat radiator, and recovery power of the expansion mechanism An auxiliary compression mechanism that is driven, a gas-liquid separator that separates a refrigerant having a reduced pressure by the expansion mechanism and a medium-pressure refrigerant that is a pressure increased by the auxiliary compression mechanism into a gas refrigerant and a liquid refrigerant, and the gas A first decompressor for decompressing the liquid refrigerant flowing out from the liquid separator; an evaporator for evaporating the refrigerant decompressed by the first decompressor; and the intermediate pressure refrigerant being decompressed by the first decompressor and the auxiliary In the refrigeration cycle apparatus including a bypass circuit that bypasses the low pressure side circuit until it is sucked into the compression mechanism, the pressure at any position between the outlet of the compression mechanism and the inlet of the expansion mechanism is The amount of circulation flowing through the expansion mechanism and the auxiliary compression mechanism so that a target high-pressure side pressure is predetermined according to the temperature at any position between the outlet of the heat radiator and the inlet of the expansion mechanism A control method for a refrigeration cycle apparatus, characterized by adjusting a ratio with a circulation amount flowing through the refrigeration cycle. At least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the heat radiator, and recovery power of the expansion mechanism An auxiliary compression mechanism that is driven, a gas-liquid separator that separates a refrigerant having a reduced pressure by the expansion mechanism and a medium-pressure refrigerant that is a pressure increased by the auxiliary compression mechanism into a gas refrigerant and a liquid refrigerant, and the gas A first decompressor for decompressing the liquid refrigerant flowing out from the liquid separator; an evaporator for evaporating the refrigerant decompressed by the first decompressor; and the intermediate pressure refrigerant being decompressed by the first decompressor and the auxiliary In the refrigeration cycle apparatus including a bypass circuit that bypasses the low-pressure side circuit until it is sucked into the compression mechanism, the expansion is performed so that the discharge temperature of the compression mechanism becomes a predetermined target discharge temperature. The method of the refrigeration cycle apparatus characterized by the ratio of the circulation amount flowing circulation amount flowing a configuration of the auxiliary compression mechanism, for adjusting. At least a compression mechanism that compresses the refrigerant, a radiator that cools the refrigerant discharged from the compression mechanism, an expansion mechanism that recovers power by reducing the pressure of the refrigerant flowing out of the heat radiator, and recovery power of the expansion mechanism An auxiliary compression mechanism that is driven, a gas-liquid separator that separates a refrigerant having a reduced pressure by the expansion mechanism and a medium-pressure refrigerant that is a pressure increased by the auxiliary compression mechanism into a gas refrigerant and a liquid refrigerant, and the gas A first decompressor for decompressing the liquid refrigerant flowing out from the liquid separator; an evaporator for evaporating the refrigerant decompressed by the first decompressor; and the intermediate pressure refrigerant being decompressed by the first decompressor and the auxiliary In a refrigeration cycle apparatus comprising a bypass circuit for bypassing to a low-pressure side circuit until being sucked into the compression mechanism, the suction superheat degree of the auxiliary compression mechanism is set to a predetermined target superheat degree. The method of the refrigeration cycle apparatus characterized by the ratio of the circulation amount flowing through the circulation amount and the auxiliary compression mechanism through the Zhang mechanism, adjusts.

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