JP4258426B2 - Refrigeration cycle equipment - Google Patents

Description

    The present invention relates to a refrigeration cycle apparatus such as a refrigeration apparatus, an air conditioner, a chiller, or a hot water supply apparatus that uses an ejector.

  Hereinafter, a control method of a refrigeration cycle apparatus using a conventional ejector will be described. A conventional refrigeration cycle apparatus using an ejector uses a combination of a first flow control valve and an ejector, and further includes a means for detecting the liquid level in the gas-liquid separator in the gas-liquid separator. In addition to controlling the amount of refrigerant, an appropriate refrigerant flow rate is controlled based on the degree of refrigerant superheating on the evaporator outlet side.

  In a conventional refrigeration cycle apparatus using an ejector, a compressor, a condenser, a first flow rate control valve, an ejector, a first evaporator, a second flow rate control valve, a second evaporator, and a gas-liquid separator are sequentially connected by piping. The gas-liquid separator is provided with a liquid level sensor as liquid level detecting means for detecting the height of the liquid level.

  This conventional refrigeration cycle apparatus using an ejector employs an electronic expansion valve for each of the first flow rate control valve and the second flow rate control valve, and the gas-liquid separator includes a liquid level sensor. Detects that the liquid level in the gas-liquid separator is not a predetermined amount, the first first flow rate adjustment control means adjusts the flow rate of the refrigerant flowing through the first flow rate adjustment valve, thereby Take control. Specifically, when the liquid level is lowered by the gas-liquid separator, the opening degree of the first flow rate control valve is increased, and the refrigerant amount is controlled so that the liquid level becomes higher. Conversely, when the liquid level is high, the opening of the first flow rate control valve is reduced to control the liquid level to be lowered. As a result, the amount of refrigerant can be controlled appropriately.

  Further, the refrigerant flow rate control of the second evaporator is performed by using, for example, a pressure sensor as a pressure detection means for detecting pressure and a temperature sensor as a temperature detection means for detecting the temperature of the evaporator, for example. The pressure P and temperature T at the outlet of the evaporator are detected, and the first second flow rate control valve control means controls the refrigerant flow rate with the second flow rate control valve so that the degree of superheat at the evaporator outlet becomes constant.

  When the liquid refrigerant is not present in the gas-liquid separator or when the liquid refrigerant is insufficient, such as during startup, the second second flow rate control valve control means fully closes the second flow rate control valve by detecting the liquid level sensor. Thus, only the first evaporator is operated. (For example, refer to Patent Document 1).

JP-A-9-318169 (pages 5-10, FIG. 1)

  As described above, a conventional refrigeration cycle apparatus using an ejector includes a means for detecting a liquid level in a gas-liquid separator, thereby appropriately controlling the amount of refrigerant and based on the degree of refrigerant superheat on the evaporator outlet side. Although it controls the appropriate refrigerant flow rate, it is necessary to provide a first flow rate adjustment valve for adjusting the amount of refrigerant in series with the ejector because the ejector has a fixed opening. The road resistance reduces the pressure difference before and after the ejector, that is, the adiabatic heat drop which is the driving force of the ejector, and the ejector efficiency is lowered. In addition, since it is necessary to provide the first flow rate control valve, there is a problem that an installation space for the first flow rate control valve is required and the apparatus becomes large. Moreover, the control method of a compressor and the switching method of the refrigerating cycle apparatus at the time of air_conditionaing | cooling operation and heating operation were not considered.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to provide a highly efficient refrigeration cycle apparatus. It is another object of the present invention to provide a small and lightweight refrigeration cycle apparatus. Another object of the present invention is to provide a refrigeration cycle apparatus that uses an ejector with a built-in variable throttle mechanism and can appropriately control the evaporation performance of two evaporators having different evaporation temperatures.

The refrigeration cycle apparatus of the present invention sequentially connects a compressor, a four-way valve, a heat source side heat exchanger, an ejector having a throttle mechanism, a first load side heat exchanger, and a gas-liquid separator, and the gas-liquid separation Connecting the compressor to the suction part side of the ejector via a second load side heat exchanger, and reversing the flow direction of the refrigerant in the heat source side heat exchanger by switching the four-way valve, When the first load side heat exchanger and the second load side heat exchanger are used as an evaporator for evaporating the refrigerant and when used as a condenser for condensing the refrigerant, the ejector can be switched during heating operation. A refrigeration cycle configured to operate as a simple throttle device is provided, and the medium to be cooled is allowed to flow in series in the order of the first load side heat exchanger and the second load side heat exchanger, and the first load side Heat exchanger cooling A medium outlet temperature and a cooled medium outlet temperature of the second load-side heat exchanger are detected, and a cooled medium outlet temperature of the first load-side heat exchanger and a cooled object of the second load-side heat exchanger are detected. The rotation speed of the compressor and the throttle opening of the throttle mechanism are controlled so that the medium outlet temperature becomes the target temperature .

  According to the present invention, it is possible to provide a refrigeration cycle apparatus capable of appropriately controlling the evaporation capacities of two evaporators having different evaporation temperatures with a simple configuration and simple control according to a load.

Embodiment 1 FIG.
Hereinafter, the refrigeration cycle apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic diagram showing a configuration of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the refrigeration cycle apparatus of the present embodiment includes an outdoor unit 100 and an indoor unit 101. The refrigerant circuit in the outdoor unit 100 includes a compressor 1, a heat source side heat exchanger 2, an ejector 3 whose throttle opening can be changed, a first load side heat exchanger 4, a gas-liquid separator 5, a throttle device 6, The two-load-side heat exchanger 7 and a pipe for connecting them are configured, and for example, R410A that is an HFC-based mixed refrigerant is enclosed as a refrigerant.

  The heat source side heat exchanger 2 is a plate fin tube type heat exchanger composed of plate fins and pipes, and includes a blower 11 that blows outside air to the outer surface of the heat exchanger. Moreover, the 1st load side heat exchanger 4 and the 2nd load side heat exchanger 7 are heat exchangers which perform heat exchange with the liquid (for example, water and brine) which is a to-be-cooled medium, for example, a double tube type A heat exchanger or a plate heat exchanger is used.

  Here, in this embodiment, the refrigeration cycle is configured in the order of the compressor 1, the heat source side heat exchanger 2, the ejector 3, the first load side heat exchanger 4, and the gas-liquid separator 5. The gas refrigerant separated by the separator 5 is returned to the suction side of the compressor 1. Further, the liquid refrigerant separated by the gas-liquid separator 5 is squeezed by the expansion device 6 and returned to the suction portion of the ejector 3 through the second load side heat exchanger 7.

  Further, a first temperature detecting means 21 is provided between the outlet portion of the first load side heat exchanger 4 and the inlet portion of the gas-liquid separator 5 (for example, piping), and the outlet portion of the expansion device 6 A second temperature detecting means 22 is provided between the inlet portion of the two load side heat exchanger 7 (for example, piping) and between the outlet portion of the second load side heat exchanger 7 and the suction portion of the ejector 3. The third temperature detection means 23 is provided in (for example, piping), and the temperature detection values detected by these temperature detection means 21, 22, 23 are taken into the control means 31.

  The control means 31 takes in the temperature detection values of the first temperature detection means 21, the second temperature detection means 22, and the third temperature detection means 23, and the temperature detection value ET2 of the second temperature detection means 22 and the third temperature detection means 23. Is calculated from the temperature detection value ET3 of the second load side heat exchanger, the temperature detection value ET1 of the first temperature detection means 21, the temperature detection value ET2 of the second temperature detection means 22, and the outlet superheat The degree SH is compared with each target value given from the outside, and the rotation speed of the compressor 1, the throttle opening of the ejector 3, and the output value of the throttle opening of the throttle device 6 are calculated. To the diaphragm device 6. Here, in the present embodiment, an example of capacity control based on the rotational speed using one inverter compressor whose rotational speed can be changed as the compressor 1 is shown, but the present invention is not limited to this, and the rotational speed is In the case of a fixed constant speed compressor, for example, simple ON / OFF control or bypass means via an opening / closing valve is provided on the suction side and the discharge side of the compressor 1, and mechanical capacity control is performed by opening / closing the opening / closing valve. Or, the number of compressors may be controlled. In the case of a constant speed compressor, the opening / closing output of the on-off valve may be transmitted from the control means 31, and in the case of a plurality of compressors, the output of the number of operating or stopped units may be transmitted from the control means 31. Therefore, in this embodiment, the compressor capacity control method has a high degree of freedom in selection, and a low-cost method can be selected according to the user's usage environment.

  The cycle of the medium to be cooled that exchanges heat with the liquid that is the medium to be cooled (for example, water or brine) includes the heat exchanger in the indoor unit 101, the first load side heat exchanger 4, and the second load side heat exchange. The units 7 are connected in series in the order.

  Next, the structure of the ejector 3 of the present embodiment will be described. FIG. 2 is a diagram showing the relationship between the structure of the ejector used in the refrigeration cycle apparatus representing Embodiment 1 of the present invention and the pressure change, and FIG. 2 (a) shows the structure of the ejector. (B) has shown the pressure distribution corresponding to the refrigerant | coolant flow direction position of the ejector in Fig.2 (a). In FIG. 2B, the horizontal axis represents the refrigerant flow direction position of the ejector in FIG. 2A, and the vertical axis represents the pressure change at each position of the ejector. In the figure, the ejector 3 is composed of a needle part 42, an electromagnetic coil part 41 for driving the needle part 42, a nozzle part 43, a mixing part 44, and a diffuser part 45. The nozzle part 43 further includes a decompression part 43a and a nozzle throat part 43c. And the divergent portion 43b. Therefore, the ejector 3 of the present embodiment has a structure in which the needle portion 42 is driven (moved) in the axial direction by the electromagnetic coil portion 41 so that the flow passage area of the nozzle throat portion 43c can be varied. It is an ejector provided with a variable degree diaphragm mechanism.

  The ejector 3 decompresses and expands the liquid refrigerant E1 having a pressure P1, which is a driving flow, by the decompression unit 43a (X1 to X2) to obtain the sound velocity of the pressure P2 by the nozzle throat 43c (X2), and further the divergent part 43b (X2 to X3). To reduce the pressure to supersonic speed to pressure P3. At this time, the gas refrigerant E4 is sucked from the surrounding gas refrigerant suction part inlet 3a, and the sucked gas refrigerant flows out of the divergent part 43b in the suction mixing part (X3 to X4) and becomes supersonic. The mixed gas-liquid two-phase refrigerant E2 is mixed, and the mixed gas-liquid two-phase refrigerant E2 is recovered in pressure by the mixing unit 44 (X4 to X5) to be in a pressure P4 state, and further, the diffuser unit 45 (X5 to X6). ) To increase to a pressure P5 and flow out.

  Next, the operation of the refrigeration cycle apparatus configured as described above will be described with reference to FIGS. FIG. 3 is a diagram showing the relationship between the pressure and enthalpy of the refrigeration cycle apparatus representing Embodiment 1 of the present invention, where the horizontal axis represents enthalpy and the vertical axis represents pressure. Here, the refrigeration cycle apparatus of the present embodiment, for example, transports a medium to be cooled while exchanging heat from an outdoor unit 100 installed outdoors to an indoor unit 101 provided indoors, and cools the room. The high-temperature and high-pressure gas refrigerant R1 (I1, Pc1) discharged from the compressor 1 dissipates heat to the air in the heat source side heat exchanger 2, condenses and liquefies, and the high-pressure liquid refrigerant R2 (I2, Pc1) And flows into the ejector 3.

  The refrigerant that has flowed into the ejector 3 enters the state R3 (I3, Pe2) at the nozzle portion 43 outlet E2 (position X3 in FIG. 2) and flows into the mixing portion 44. After mixing with the refrigerant gas of R4 (I8, Pe2) flowing in from the state E4 in the mixing unit 44, the refrigerant in the state of R5 (I5, Pe2) is restored in pressure from Pe2 to Pe1 by the diffuser 45, and the state R6 The state is (I6, Pe1). The refrigerant depressurized by the ejector 3 flows into the first load-side heat exchanger 4, takes heat from the medium to be cooled, and part of the liquid refrigerant evaporates to be in the state R7 (I7, Pe1). Flows into the vessel 5. In the gas-liquid separator 5, the gas refrigerant and the liquid refrigerant are separated, the saturated gas refrigerant in the state R8 (I8, Pe1) is throttled to the suction portion of the compressor 1, and the liquid refrigerant in the state R9 (I9, Pe1) is throttled. The pressure is reduced by the device 6, flows into the second load side heat exchanger 7, evaporates and becomes a gas refrigerant in the state R 4 (I 8, Pe 2) and is sucked into the suction part E 4 of the ejector 3. As described above, in the present embodiment, since the ejector 3 is used in the refrigeration cycle, the suction pressure of the compressor 1 can be increased from Pe2 to Pe1, and the compressor is operated with a small compression ratio. Therefore, highly efficient operation is possible. In this embodiment, Pc1> Pc2> Pe1> Pe2 and I1> I8> I7> I6> I5> I2> I2 '> I3> I9.

  Here, the driving force of the ejector 3 is an enthalpy difference ΔH (= I2−I3) between the enthalpy I3 at the time of isentropic expansion and the enthalpy I2 at the time of isoenthalpy expansion. The larger the enthalpy difference ΔH, the greater the effect of introducing the ejector. Generally, the enthalpy difference ΔH increases as the pressure difference ΔPc (= Pc1−Pe2) between the high pressure Pc1 and the low pressure Pe2 increases. In the prior art, a first flow rate adjustment valve is provided on the upstream side of the ejector 3, and a pressure loss occurs in the valve portion of the first flow rate adjustment valve to reduce the pressure difference ΔPc. A certain enthalpy difference ΔH decreases.

  That is, in the prior art, it is necessary to provide a first flow rate control valve, and by providing this first flow rate control valve, the state changes from R2 (I2, Pc1) to R2 ′ (I2) due to pressure loss when flowing into the ejector. ', Pc2), the pressure difference ΔPc decreases from (Pc1-Pe2) to (Pc2-Pe2), and the enthalpy difference ΔH decreases from (I2-I3) to (I2'-I3). Become.

  Further, the ejector 3 of the present embodiment includes a throttle unit 43a that depressurizes the refrigerant flowing in the refrigeration cycle, a suction unit 3a that sucks the refrigerant in the refrigeration cycle due to a pressure difference, and a refrigerant that is depressurized by the throttle unit 43a. A mixing unit 44 that mixes the refrigerant sucked by the suction unit 3a, and the throttle opening of the throttle unit 43a can be variably controlled by the axial movement control of the needle 42. Since the configuration can be changed, it is not necessary to separately use a flow valve or the like as in the prior art, and highly efficient operation is possible without reducing the driving force of the ejector 3.

  Next, a method for controlling the compressor 1, the ejector 3, and the expansion device 6 will be described. First, the temperature detection values detected by the first temperature detection means 21, the second temperature detection means 22, and the third temperature detection means 23 are taken into the control means 31. The control means 31 calculates the rotational speed of the compressor 1 based on the deviation between the temperature detection value ET1 of the first temperature detection means 21 and the target evaporation temperature ET1m, and the temperature detection value ET2 of the second temperature detection means 22 and the target Based on the deviation from the evaporation temperature ET2m, the throttle opening of the ejector 3 is calculated, and the second load side heat exchanger outlet overheat calculated from the temperature detection value ET3 of the second temperature detection means 22 and the third temperature detection means 23. The throttle opening degree of the expansion device 6 is calculated based on the deviation between the degree SH and the target outlet superheat degree SHm, and is output to the compressor 1, the ejector 3, and the expansion device 6. The second load side heat exchanger outlet superheat degree SH is calculated by calculating the second load side heat exchanger outlet temperature (for example, the detected temperature of the third temperature detecting means 23) ET3 and the inlet temperature (for example, detecting the second temperature detecting means 22). Temperature) It may be calculated as a difference from ET2 (SH = ET3-ET2), or from a detected value P3 from pressure detecting means (for example, a pressure sensor) separately provided at the outlet portion of the second load side heat exchanger What is necessary is just to obtain | require as a difference (SH = ET3-ET2) of the saturation temperature ET3 calculated | required and the 2nd load side heat exchanger exit temperature (for example, detection temperature of the 2nd temperature detection means 22).

  FIG. 4 is a control flow diagram of the refrigeration cycle apparatus representing Embodiment 1 of the present invention. In the present embodiment, the rotational speed control of the compressor 1 determines the flow rate of refrigerant circulating through the refrigeration cycle apparatus, that is, the refrigeration capacity, so that the influence on the whole is large and the highest priority is given from the viewpoint of load followability. . Further, the throttle opening degree control of the ejector 3 determines the ratio of the heat exchange amount between the first load-side heat exchanger 4 and the second load-side heat exchanger 7, and therefore, the compressor rotational speed from the viewpoint of operating efficiency. Takes precedence over control. The throttle opening degree control of the expansion device 6 determines the refrigerant outlet state of the second load side heat exchanger 7, and is set to the lowest priority from the viewpoint of the operation efficiency of the second load side heat exchanger 7. Yes.

  In the figure, ST1 is a throttle device throttle opening setting step for setting the throttle opening of the throttle device 6 (only the initial value is given a preset value as a predetermined value), and ST2 is an ejector throttle for setting the throttle opening of the ejector 3 ST is an opening setting step (only the initial value is given as a predetermined value in advance), and ST3 is a compressor speed setting step (set only as the initial value is given as a predetermined value) for setting the rotational speed of the compressor. is there. ST4 is a first evaporating temperature determining step for determining a deviation by comparing the detected temperature ET1 of the first temperature detecting means 21 with the target evaporating temperature ET1m and determining whether the absolute value of the deviation is smaller than a predetermined value ε3. is there. In ST4, the detected temperature ET1 of the first temperature detecting means 21 is compared with the target evaporation temperature ET1m in ST4 to obtain a deviation, and when the absolute value of the deviation is smaller than a third predetermined value ε3, the compressor 1 ST6 is a step for determining the number of rotations of the compressor. ST6 compares the detected temperature ET2 of the second temperature detecting means 22 with the target evaporation temperature ET2m to determine whether the absolute value of the deviation is smaller than a predetermined value ε2. The second evaporating temperature determining step ST7 is a step ST6 where the detected temperature ET2 of the second temperature detecting means 22 is compared with the target evaporating temperature ET2m and the absolute value of the deviation is smaller than the second predetermined value ε2, the ejector 3 This is an ejector throttle opening degree setting step for setting the throttle opening degree.

  ST8 compares the second load side heat exchanger outlet superheat degree SH with the target outlet superheat degree SHm, and determines whether the deviation is smaller than the first predetermined value ε1, ST9 In ST8, the second load side heat exchanger outlet superheat degree SH is compared with the target outlet superheat degree SHm, and when the absolute value of the deviation is smaller than the first predetermined value ε1, the throttle opening degree of the expansion device 6 This is a throttle device throttle opening setting step.

  In ST1, the initial opening of the expansion device 6 is set, in ST2, the initial throttle opening of the ejector 3 is set, and in ST3, the initial rotational speed of the compressor 1 is set. In ST4, the rotational speed of the compressor 1 is controlled so that the evaporation temperature ET1 of the first load side heat exchanger 4 becomes a preset target evaporation temperature ET1m (| ET1-ET1m | <ε3). Control. ). Specifically, when ET1−ET1m> ε3 (the third predetermined value ε3 is a positive number), the rotational speed of the compressor 1 is increased, and when ET1m−ET1> ε3, the compressor 1 is increased. And the process returns to ST3 and repeats until the absolute value of ET1-ET1m satisfies | ET1-ET1m | <ε3. As a result, the absolute value of ET1-ET1m satisfies | ET1-ET1m | <ε3, and the rotational speed of the compressor 1 at that time is determined as a set value (ST5).

  Similarly, in ST6, the throttle opening of the ejector 3 is controlled so that the evaporation temperature ET2 of the second load side heat exchanger 7 becomes the preset target evaporation temperature ET2m (the absolute value of ET2-ET2m is | ET2 -ET2m | <ε2 is controlled.) Specifically, when ET2−ET2m> ε2 (ε2 is a positive number), the throttle opening of the ejector 3 is decreased, and when ET2m−ET2> ε2, the throttle opening of the ejector 3 is increased. And return to ST2 and repeat until the absolute value of ET2-ET2m satisfies | ET2-ET2m | <ε2. As a result, the absolute value of ET2-ET2m satisfies | ET2-ET2m | <ε2, and the throttle opening of the ejector 3 at that time is determined as the throttle opening of the ejector 3 (ST7).

  Furthermore, in ST8, the throttle opening degree of the expansion device 6 is controlled so that the outlet superheat degree SH of the second load side heat exchanger 7 becomes a preset target outlet superheat degree SHm (the absolute value of SH-SHm is | SH-SHm | <ε1 is controlled). Specifically, when SH-SHm> ε1 (ε1 is a positive number), the opening degree of the expansion device 6 is decreased, and when SHm-SH> ε1, the opening amount of the expansion device 6 is increased. Then, return to ST1 and repeat until the absolute value of SH-SHm satisfies | SH-SHm | <ε1. As a result, the absolute value of SH-SHm satisfies | SH-SHm | <ε1, and the throttle opening of the expansion device 6 is determined (ST9).

  The rotation speed of the compressor 1, the throttle opening of the ejector 3, and the throttle of the throttle device 6 obtained from the deviation between the temperature detection values of the temperature detection means 21, 22, and 23 described above and the calculated values using them and the target value. For example, a PID control method is used to determine the opening degree.

  Next, a method for setting a target value will be described. The target evaporation temperature ET1m of the first load-side heat exchanger 4 is, for example, the suction temperature, the blowing temperature, the air volume of the indoor unit 101 (not shown), the load-side inlet temperature of the first load-side heat exchanger 4 of the medium to be cooled, the load side External information such as the outlet temperature, flow rate, outside air temperature, and rotation speed of the compressor is detected and determined from the necessary capacity of the first load side heat exchanger 4 calculated from the detected value based on the relationship shown in FIG. . FIG. 5 is a diagram showing the relationship between the evaporation capacity Q1 and the evaporation temperature ET1 in the first load-side heat exchanger 4 in the refrigeration cycle apparatus according to Embodiment 1 of the present invention. The flow rate Gw of the flowing medium to be cooled is a parameter, the horizontal axis indicates the evaporation capacity Q1 of the first load side heat exchanger 4, and the vertical axis indicates the evaporation temperature ET1. In FIG. 5, the magnitude relationship of the flow rate of the medium to be cooled flowing through the first load-side heat exchanger 4 is Gw1> Gw2> Gw3. In the figure, the evaporation temperature ET1 decreases as the evaporation capability Q1 increases, and with the same evaporation capability, the evaporation temperature ET1 increases as the flow rate of the medium to be cooled increases. For example, when the target value Q1m of the required evaporation capacity Q1 is determined from the external information including the flow rate Gw2 of the medium to be cooled as indicated by the arrows in the figure, the target evaporation temperature ET1m is determined from FIG.

  Next, the target evaporating temperature ET2m of the second load side heat exchanger 7 is, for example, the suction temperature, the blowing temperature, the air volume of the indoor unit 101 (not shown), the load side inlet temperature of the first load side heat exchanger 4 of the medium to be cooled. Based on the relationship shown in FIG. 7 based on the necessary capacity of the second load-side heat exchanger 7 that is detected from external information such as the load-side outlet temperature, the flow rate, the outside air temperature, and the rotational speed of the compressor. It is determined. FIG. 7 is a view showing the relationship between the suction flow rate (Gre) of the ejector and the pressure difference (ΔP) of the refrigeration cycle apparatus according to Embodiment 1 of the present invention, and the rotation speed (Hz) of the compressor 1 as a parameter. The horizontal axis represents the suction flow rate Gre sucked by the ejector 3, that is, the evaporation capacity Q2 of the second load side heat exchanger 7, and the vertical axis represents the saturation pressure Pe1 at the evaporation temperature ET1 of the first load side heat exchanger 4. The relationship of the difference ((DELTA) P = Pe1-Pe2) with the saturation pressure Pe2 at the time of evaporation temperature ET2 of the 2nd load side heat exchanger 7 is shown. In FIG. 7, the magnitude relationship of the rotation speed of the compressor 1 is set to Hz1> Hz2> Hz3. Since the ejector 3 functions as a gas pump that sucks and raises the refrigerant gas, as shown in FIG. 7, the suction flow rate (Gre) decreases as the pressure difference (ΔP) increases, and the compressor 1 rotates at the same suction flow rate. The larger the number, the greater the difference between the high and low pressures of the refrigeration cycle, and the greater the pressure difference (ΔP) that can be increased by the ejector.

  Therefore, when the target evaporation temperature ET2m of the second load side heat exchanger 7 is input based on external information, the target evaporation temperature ET1m of the first load side heat exchanger 4 and the target evaporation of the second load side heat exchanger 7 are input. A difference (ΔETm = ET1m−ET2m) from the temperature ET2m is obtained, and a target pressure difference (ΔPm) can also be obtained correspondingly. Therefore, by controlling the pressure difference ΔP to be the target pressure difference ΔPm, the suction flow rate Gre corresponding to the rotation speed (Hz) of the compressor 1 as shown by the arrow in the drawing, that is, the second load side heat exchange is shown. The target capacity Q2m of the vessel 7 can be obtained, and the evaporation temperature ET2 of the second load side heat exchanger 7 is also controlled to the target evaporation temperature ET2m. Here, how to obtain the target evaporation temperature ET2m will be described. When the target capacity Q2m is obtained, the target pressure difference ΔPm is obtained from the figure, and when the target pressure difference ΔPm is obtained, the target evaporation temperature difference ΔETm is obtained from the refrigerant physical property value, and when the target evaporation temperature difference ΔETm is obtained, ΔETm = The target evaporation temperature ET2m is obtained from the relationship ET1m-ET2m. Therefore, the target evaporation temperature ET2m can be obtained by back calculation from the target pressure difference ΔPm. The target outlet superheat degree (SHm) is determined regardless of external information and is fixed to a value of about 5 to 15 deg, for example.

Here, a method for calculating the capacity Q1 and the target capacity Q1m of the first load side heat exchanger 4 from external information will be described. The capacity Q1 of the first load side heat exchanger 4 is the load side inlet temperature, the load side outlet temperature, the flow rate (or the first load side heat exchanger 4 of the first load side heat exchanger 4) of the medium to be cooled (not shown). The total capacity deficiency ΔSQ (= ΔQ1 + ΔQ2) is obtained from the difference ΔT (= Tain−Tset) between the indoor set air temperature Tset and the intake air temperature Tain of the indoor unit 101, which is obtained from the load side inlet temperature, the evaporation temperature ET1, and the flow rate. ) Is calculated, and the capacity shortage amount ΔQ1 of the first load side heat exchanger 4 is calculated. Here, the relationship between ΔT and the capacity shortage ΔSQ and the relationship between ΔSQ and ΔQ1 may be stored in advance in, for example, a microcomputer in the control means 31. In this case, if ΔT is obtained, ΔSQ can be obtained. , ΔQ1 can also be obtained.
Further, since ΔQ1 is obtained, ΔQ2 is also obtained (ΔQ2 = ΔSQ−ΔQ1). Next, the target evaporation capacity Q1m is obtained as Q1m = Q1 + ΔQ1 from the capacity shortage amount ΔQ1 and the evaporation capacity Q1 of the first load side heat exchanger 4. The capacity Q2 of the second load-side heat exchanger 7 is determined by the load-side inlet temperature, the load-side outlet temperature, the flow rate (or the second load-side heat exchanger) of the second load-side heat exchanger 7 of the medium to be cooled (not shown). 7), the target capacity Q2m can be obtained as Q2m = Q2 + ΔQ2 = Q2 + (ΔSQ−ΔQ1).

  In the present embodiment, the control flow in the case where the evaporation temperature ET1 is controlled by the compressor 1 and the evaporation temperature ET2 is controlled by the ejector 3 is shown. However, the control object of the compressor 1 and the ejector 3 is controlled depending on the purpose of use and the cycle configuration. The evaporating temperatures (ET1, ET2) can be exchanged, and the same effect is exhibited even in this case. For example, as shown in FIG. 6, the rotation speed of the compressor 1 is controlled so that the evaporation temperature ET2 of the second load side heat exchanger 7 becomes the target evaporation temperature ET2m, and the throttle opening of the ejector 3 is set to the first load. It can also be controlled so that the evaporation temperature ET1 of the side heat exchanger 4 becomes the target evaporation temperature ET1m.

  FIG. 6 is another control flow diagram of the refrigeration cycle apparatus representing Embodiment 1 of the present invention. 4 and FIG. 1 to FIG. 5 are denoted by the same reference numerals, and description thereof is omitted. In the figure, ST11 to ST13 are the same as ST1 to ST3 described in FIG. ST14 compares the detected temperature ET2 of the second temperature detecting means 22 with the target evaporation temperature ET2m to obtain a deviation, and determines whether or not the absolute value of the deviation is smaller than a predetermined value ε2, ST15 is a step ST15. In ST14, the detected temperature ET2 of the second temperature detecting means 22 is compared with the target evaporation temperature ET2m to obtain a deviation. When the absolute value of the deviation is smaller than the second predetermined value ε2, the rotational speed of the compressor 1 is set. The compressor rotation speed determination step to be determined, ST16 compares the detected temperature ET1 of the first temperature detecting means 21 with the target evaporation temperature ET1m and determines whether or not the absolute value of the deviation is smaller than a predetermined value ε3. In the determination step, ST17, the detected temperature ET1 of the first temperature detecting means 21 is compared with the target evaporation temperature ET1m in ST16, and the absolute value of the deviation is smaller than the third predetermined value ε3. If have a ejector aperture opening setting step determines the throttle opening of the ejector 3. ST18 and ST19 are the same as described above.

  In ST14, the rotation speed of the compressor 1 is controlled so that the evaporation temperature ET2 of the second load side heat exchanger 7 becomes a preset target evaporation temperature ET2m, and in ST16, the throttle opening of the ejector 3 is set to the first load. Control is performed so that the evaporation temperature ET1 of the side heat exchanger 4 becomes a preset target evaporation temperature ET1m. At this time, the difference from FIG. 4 is that, when the determination condition in ST14 (| ET2-ET2m | <ε2) is not satisfied, the throttle opening degree of the expansion device 6 and the ejector 3 according to the rotational speed of the compressor 1 are different. The throttle opening is also changed, and when the determination condition in ST16 (| ET1-ET1m | <ε3) is not satisfied, the rotation speed of the compressor 1 and the throttle opening of the expansion device 6 according to the throttle opening of the ejector 3 Is also changed. This change also applies to ST18. When the determination condition of ST18 (| SH-SHm | <ε1) is not satisfied, the rotational speed of the compressor 1 and the ejector 3 The throttle opening is also changed. Further, the method for setting the target value is the same as described above, and therefore the description thereof is omitted. Furthermore, in the present embodiment, an example is shown in which priority is given in the order of the compressor 1, the ejector 3, and the expansion device 6, but control is appropriately performed according to the purpose of use and the configuration of the cycle (compressor). 1, the priority order of the ejector 3 and the expansion device 6) may be switched, and the same effect can be obtained by controlling the compressor 1, the ejector 3 and the expansion device 6 simultaneously.

  Further, the rotational speed of the compressor 1 is controlled so that the total capacity SQ of the evaporation capacity Q1 of the first load side heat exchanger 4 and the evaporation capacity Q2 of the second load side heat exchanger 7 becomes the target total capacity SQm. The throttle opening degree of the ejector 3 may be controlled so that the capacity Q2 of the second load side heat exchanger 7 becomes the target capacity Q2m. In this case, the current value of the total capacity SQ is obtained from the suction temperature (not shown) of the indoor unit 101, the inlet temperature of the indoor unit 101 of the medium to be cooled, and the air volume, and the difference ΔT between the indoor set temperature Tset and the suction temperature Tain of the indoor unit 101 is obtained. The ability shortage amount ΔSQ is obtained from (= Tain−Tset), and the target total ability SQm is obtained as SQm = SQ + ΔSQ. At this time, the relationship between ΔT and the capacity shortage amount ΔSQ and the relationship between ΔSQ and ΔQ1 may be stored in advance in a storage unit such as a microcomputer in the control unit 31, for example. The capacity Q2 of the second load-side heat exchanger 7 is determined by the load-side inlet temperature, the load-side outlet temperature, the flow rate (or the second load-side heat exchanger) of the second load-side heat exchanger 7 of the medium to be cooled (not shown). 7), the target capacity Q2m is obtained as Q2m = Q2 + (ΔSQ−ΔQ1).

  In the control flow of FIGS. 4 and 6 described in the present embodiment, an example in which an inverter compressor capable of changing the rotation speed is used as the compressor 1 is shown. However, the rotation speed cannot be changed. In the case of a high-speed compressor, for example, a bypass means via an on-off valve may be provided in the suction part and the discharge part of the compressor 1 so that mechanical capacity control can be performed by opening / closing the on-off valve. The opening / closing control of the bypass means of the compressor 1 is performed instead of the rotational speed control of the compressor 1. When a plurality of compressors 1 are provided, the number control may be performed instead of the rotation speed control of the compressor 1.

  In the present embodiment, the configuration in which the first temperature detection means 21 is provided at the outlet portion of the first load-side heat exchanger 4 is shown. However, since the refrigerant is in a gas-liquid two-phase state, the first temperature detection means is installed. The position is not limited to this. In other words, any of the piping between the ejector 3 and the first load side heat exchanger 4, the gas-liquid separator 5, and the piping between the gas-liquid separator 5 and the expansion device 6 may be provided. The same effect is demonstrated.

  As described above, in the present embodiment, the compressor 1, the heat source side heat exchanger 2, the throttle opening variable ejector 3, the first load side heat exchanger 4, and the gas-liquid separator 5 are sequentially connected. The gas-liquid separator 5 is connected to the suction portion side of the ejector 3 via the expansion device 6 and the second load side heat exchanger 7 to constitute a refrigeration cycle, and the capacity of the first load side heat exchanger 4 or Since the capacity of the second load side heat exchanger 7 is controlled by the control means 31 by the throttle opening of the ejector 3, there is no need to provide a separate throttle mechanism or the like upstream of the ejector, and the configuration is simple and low. A cost refrigeration cycle apparatus can be provided. Further, it is possible to provide a refrigeration cycle apparatus capable of appropriately controlling the evaporation capacities of two evaporators having different evaporation temperatures according to the load.

  In the present embodiment, by controlling the rotation speed of the compressor 1, the throttle opening of the ejector 3, and the throttle opening of the expansion device 6, the evaporation temperature ET1 of the first load side heat exchanger, the second load Since the evaporating temperature ET2 of the side heat exchanger and the outlet superheat degree SH of the second load side heat exchanger can be appropriately controlled, the capacities of the two evaporators having different evaporating temperatures are appropriately controlled according to the load. be able to.

  In particular, in the present embodiment, the compressor 1, the heat source side heat exchanger 2, the ejector 3 with a variable throttle opening, the first load side heat exchanger 4, and the gas-liquid separator 5 are sequentially connected, and the gas-liquid The separator 5 is connected to the suction unit side with the ejector 3 via the expansion device 6 and the second load side heat exchanger 7 to constitute a refrigeration cycle. The capacity of the first load side heat exchanger 4 is Since the control is performed by controlling the throttle opening, and the capacity of the second load-side heat exchanger 7 is controlled by the capacity control of the compressor 1, the first load-side heat exchanger 4 and the second Since the load side heat exchanger 7 can be individually controlled, the ability of two evaporators having different evaporation temperatures can be appropriately controlled according to the load while being simple control.

  Further, the capacity of the second load-side heat exchanger 7 is controlled by controlling the throttle opening of the ejector 3, and the capacity of the first load-side heat exchanger 4 is controlled by controlling the capacity of the compressor 1. Since the first load side heat exchanger 4 and the second load side heat exchanger 7 can be controlled individually, the ability of two evaporators having different evaporation temperatures according to the load can be easily controlled. Can be controlled appropriately.

  In addition, the pipe temperature can be detected using inexpensive temperature detection means (for example, a temperature thermistor or thermocouple) or pressure detection means (for example, a pressure sensor). A highly reliable refrigeration cycle apparatus can be obtained. Furthermore, since the ejector 3 has a built-in throttle mechanism, it is not necessary to separately use an expansion valve or the like on the upstream side of the ejector 3, and both the throttle effect and the ejector effect can be operated effectively only by the ejector 3. Moreover, since there is no need to use a separate expansion valve or the like, the installation space can be reduced, and a small and low-cost refrigeration cycle apparatus can be provided.

  Further, the refrigerant outlet state of the second load side heat exchanger 7 (for example, the refrigerant outlet superheat calculated by the pressure and temperature of the refrigerant outlet portion of the second load side heat exchanger 7 or the second load side heat exchanger 7 The refrigerant outlet superheat calculated by the refrigerant inlet temperature and the refrigerant outlet temperature is controlled by the throttle opening degree of the expansion device 6, so that the evaporation can be accurately performed by simple control with a low-cost measuring means. The capacities of the two evaporators having different temperatures can be appropriately controlled according to the load.

Embodiment 2. FIG.
FIG. 8 is a diagram showing a configuration of a refrigeration cycle apparatus representing Embodiment 2 of the present invention. In Embodiment 1, one indoor unit 101 is connected to the outdoor unit 100. However, in this embodiment, the outdoor unit 100 is connected to two indoor units 101 and 102 having different required temperatures. The case will be described. In the figure, the same parts as in FIGS. 1 to 7 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the first embodiment, the cycle of the medium to be cooled that exchanges heat with the liquid (for example, water or brine) that is the medium to be cooled includes the heat exchanger in the indoor unit 101, the first load-side heat exchanger 4, and the second. Although the load-side heat exchanger 7 is connected in series in this order, in the present embodiment, the first load-side heat exchanger 4 is connected to the indoor unit 101, and the second load-side heat exchange is connected to the indoor unit 102. The temperature of the to-be-cooled medium which flows out from two load side heat exchangers (the 1st load side heat exchanger 4 and the 2nd load side heat exchanger 7) is each detected. Then, the number of rotations of the compressor 1 and the opening degree of the ejector 3 are controlled. In this embodiment, two cases are described as loads having different required temperatures. However, the number of loads is not limited to two, and a plurality of loads may be provided. In this case, a plurality of load-side heat exchangers may be provided and the temperatures of the cooling medium flowing out from the plurality of load-side heat exchangers may be detected.

  In FIG. 8, the fourth temperature detecting means 24 is provided at the load side outlet portion of the first load side heat exchanger 4, and the fifth temperature detecting means 25 is provided at the load side outlet portion of the second load side heat exchanger 7. The second temperature detecting means 22 is provided in the pipe between the outlet portion of the expansion device 6 and the inlet portion of the second load side heat exchanger 7, and the outlet portion of the second load side heat exchanger 7 is provided. The temperature detection value detected by these temperature detection means is taken in by the control means 31 in the piping between the suction portion of the ejector 3 and the ejector 3.

  The control means 31 takes in the temperature detection values of the second temperature detection means 22, the third temperature detection means 23, the fourth temperature detection means 24, and the fifth temperature detection means 25, The outlet superheat degree of the second load side heat exchanger 7 is calculated from the temperature detection value of the third temperature detector 23, and the fourth temperature detector 24, the fifth temperature detector 25, and the outlet superheat degree are given from the outside. Compared with the respective target values, the output values of the rotational speed of the compressor 1, the throttle opening of the ejector 3 and the throttle opening of the throttle device 6 are calculated and output to the compressor 1, the ejector 3 and the throttle device 6. .

  Next, a method for controlling the compressor 1, the ejector 3, and the expansion device 6 will be described. The control means 31 calculates the throttle opening of the ejector 3 based on the deviation between the temperature detection value Tw1 of the fourth temperature detection means 24 and the target outlet temperature Tw1m, and the temperature detection value Tw2 of the fifth temperature detection means 25 and the target The second load side is calculated from the temperature detection value ET2 of the second temperature detection means 22 and the temperature detection value ET3 of the third temperature detection means 23, based on the deviation from the outlet temperature Tw2m. Based on the deviation between the heat exchanger outlet superheat degree SH and the target outlet superheat degree SHm, the throttle opening degree of the expansion device 6 is calculated and output to the compressor 1, the ejector 3, and the expansion device 6.

  Specifically, when the temperature detection value Tw1−target outlet temperature Tw1m> the fourth predetermined value ε4 (ε4 is a positive number) of the fourth temperature detection means 24, the throttle opening of the ejector 3 is increased, When the target outlet temperature Tw1m−the temperature detection value Tw1 of the fourth temperature detecting means 24> the fourth predetermined value ε4, the throttle opening of the ejector 3 is decreased so that the absolute value of TW1-TW1m is | TW1- Repeat until TW1m | <ε4 is satisfied. Further, when the temperature detection value Tw2−target outlet temperature Tw2m> the fifth predetermined value ε5 (ε5 is a positive number) of the fifth temperature detection means 25, the rotational speed of the compressor 1 is increased, and the target outlet temperature When Tw2m−the temperature detection value Tw2 of the fifth temperature detection means 25> the fifth predetermined value ε5, the value is decreased, and the process is repeated until the absolute value of TW2−TW2m satisfies | TW2−TW2m | <ε5. Here, in the control flow and the target value setting method, the target evaporation temperature ET1m of the first load-side heat exchanger 4 is replaced with the target outlet temperature Tw1m in the first embodiment, and the target of the second load-side heat exchanger 7 is set. Since this is the same as the case where the evaporation temperature ET2m is replaced with the target outlet temperature Tw2m, detailed description thereof is omitted.

  In the present embodiment, the capacity control is not performed indirectly from the refrigerant temperature, but the outlet temperature Tw1 of the cooled medium of the first load-side heat exchanger 4 and the cooled medium of the second load-side heat exchanger 7 are controlled. Since the load side temperature such as the outlet temperature Tw2 is directly detected to control the rotation speed of the compressor 1 and the throttle opening of the ejector 3, the two evaporations are different even when the evaporation temperatures of the two evaporators are different. The capacity of the vessel can be controlled appropriately. In addition, even when there are two loads having different required temperatures, it is possible to provide a refrigeration cycle apparatus that can be controlled to a required capacity.

Embodiment 3 FIG.
FIG. 9 is a schematic diagram showing a configuration of a refrigeration cycle apparatus according to Embodiment 3 of the present invention. 9, the same parts as those in the first embodiment, the second embodiment, and FIGS. 1 to 8 are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 9, the refrigeration cycle apparatus according to the present embodiment has a four-way valve 8, a first flow path switching valve 9, a second flow path switching valve 10, and an open / close so that a cooling operation and a heating operation can be switched. The valve 12 is added to the first and second embodiments, and the flow switching control of the four-way valve 8, the first flow switching valve 9, and the second flow switching valve 10 is performed by cooling and heating. Opening / closing control of the opening / closing valve 12 is performed. Here, in the present embodiment, the compressor 1, the four-way valve 8, the heat source side heat exchanger 2, the ejector 3 capable of changing the throttle opening, the first load side heat exchanger 4, and the first flow path switching valve 9 are used. (Having the first connection port 9a, the second connection port 9b, the third connection port 9c), the gas-liquid separator 5, the expansion device 6, the on-off valve 12, the second load-side heat exchanger 7, the second flow path switching It consists of a valve 10 (having a first connection port 10a, a second connection port 10b, and a third connection port 10c), and piping for connecting them. Here, in the present embodiment, an example in which a first three-way valve is used as the first flow path switching valve 9 and a second three-way valve is used as the second flow path switching valve 10 will be described.

  Here, in the present embodiment, the refrigerant flow paths (connection ports) of the four-way valve 8, the first flow path switching valve (first three-way valve) 9, and the second flow path switching valve (second three-way valve) 10 are switched. Thus, the refrigeration cycle is switched between cooling and heating. In the case of cooling, the on-off valve 12 is closed, and the compressor 1, the four-way valve 8, the heat source side heat exchanger 2, the ejector 3, the first load side heat exchanger 4, the first three-way valve 9 (first connection port) 9a is connected to the first load side heat exchanger 4, the second connection port 9b is connected to the gas-liquid separator 5, and the first connection port 9a and the second connection port 9b communicate with each other), The refrigeration cycle is configured in the order of the gas-liquid separator 5, and the gas refrigerant separated by the gas-liquid separator 5 is returned to the suction side of the compressor 1. In addition, the liquid refrigerant separated by the gas-liquid separator 5 is throttled by the expansion device 6 and then the second load side heat exchanger 7 and the second three-way valve 10 (the first connection port 10a is the second load side heat exchanger). 7, the second connection port 10 b is connected to the suction portion side of the ejector 3, and the first connection port 10 a and the second connection port 10 b are in communication with each other to the suction portion of the ejector 3. Returned.

  In the case of heating, the on-off valve 12 is opened, and the compressor 1, the four-way valve 8, the gas-liquid separator 5, the on-off valve 12, the second load side heat exchanger 7, the second three-way valve 10 (first connection). The port 10a is connected to the second load side heat exchanger 7, the third connection port 10c is connected to the third connection port 9c of the first three-way valve 9, and the first connection port 10a and the third connection port 10c are connected. The first three-way valve 9 (the first connection port 9a is connected to the first load-side heat exchanger 4 and the third connection port 9c is connected to the third connection port 10c of the second three-way valve 10). The first connection port 9a and the third connection port 9c communicate with each other), the first load side heat exchanger 4, the ejector 3, and the heat source side heat exchanger 2 are configured in this order. .

  Further, the load-side heat medium (cooled medium or heated medium) flows in series through the first load-side heat exchanger 4 and the second load-side heat exchanger 7, and the load side of the first load-side heat exchanger 4. Fourth temperature detecting means 24 for detecting the outlet temperature (load side inlet temperature of the second load side heat exchanger), fifth temperature detecting means 25 for detecting the load side outlet temperature of the second load side heat exchanger 7, Sixth temperature detecting means 26 for detecting the load side inlet temperature of the one load side heat exchanger 4 is provided. These temperature detection values are taken into the control means 31.

  Here, the description of the operation parts equivalent to those in the first embodiment and the second embodiment is omitted, and only differences from the first embodiment and the second embodiment will be described. In the present embodiment, the four-way valve 8 is connected to the discharge part of the compressor 1, and the first three-way valve 9 is connected to the pipe between the outlet part of the first load side heat exchanger 4 and the gas-liquid separator 5, A second three-way valve 10 is provided between the outlet portion of the second load side heat exchanger 7 and the suction portion of the ejector 3, and between the gas-liquid separator 5 and the inlet portion of the second load side heat exchanger 7. Is provided with an on-off valve 12 (for example, an electromagnetic valve) for bypassing the expansion device 6 during heating operation.

  The operation of the refrigeration cycle apparatus configured as described above will be described. The refrigeration cycle apparatus according to the present embodiment, for example, connects an outdoor unit installed indoors and an indoor unit by piping or the like, and sends cold water or hot water from an outdoor unit installed outdoors to an indoor unit installed indoors. , It operates as a heat pump type cold / hot water supply device for cooling or heating the room.

  In the cooling operation, the four-way valve 8, the first three-way valve 9, and the second three-way valve 10 are connected as indicated by solid arrows, and the on-off valve 12 is closed. At this time, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the heat source side heat exchanger 2 through the four-way valve 8. The liquid refrigerant condensed and liquefied by the heat source side heat exchanger 2 is decompressed by the ejector 3 to become a low temperature / low pressure gas / liquid two-phase refrigerant and flows into the first load side heat exchanger 4. A part of the liquid refrigerant evaporates in the first load-side heat exchanger 4, and the gas-liquid two-phase refrigerant having increased dryness passes through the first three-way valve 9 (first connection port 9a, second connection port 9b). It flows into the gas-liquid separator 5. Of the gas-liquid two-phase refrigerant that has flowed into the gas-liquid separator 5, the gas refrigerant is sucked into the compressor 1 through the four-way valve 8, and the liquid refrigerant is depressurized by the expansion device 6, and the second load side heat exchanger 7. Flow into. The gas refrigerant evaporated in the second load side heat exchanger 7 is sucked into the suction portion of the ejector 3 through the second three-way valve 10 (first connection port 10a, second connection port 10b).

  Control operations of the compressor 1, the ejector 3, and the expansion device 6 during the cooling operation will be described. Based on the detection value of each temperature detection means taken into the control means 31, the compressor 1, the ejector 3, and the expansion device 6 are controlled. The rotation speed of the compressor 1 is controlled such that the detection value Tw2 of the fifth temperature detection means 25 becomes the target outlet temperature Tw2m, and the throttle opening degree of the ejector 3 is determined by the detection value Tw1 of the fourth temperature detection means 24. It is controlled to be Tw1m.

  FIG. 10 is a diagram showing the relationship between the coefficient of performance (COP) of the refrigeration cycle apparatus according to Embodiment 3 of the present invention and the load-side outlet temperature of the first load-side heat exchanger 4. In the figure, the horizontal axis represents the load-side outlet temperature Tw1 of the first load-side heat exchanger 4, the vertical axis represents the coefficient of performance COP, and represents the result of the simulation. For example, as simulation conditions, the total capacity SQ of the first load side heat exchanger 4 and the second load side heat exchanger 7 is constant, the evaporation temperature ET2 of the second load side heat exchanger 7 is 3 ° C., the first load The load side inlet temperature Tw0 of the side heat exchanger 4 = 12 ° C., the load side outlet temperature Tw2 = 7 ° C. of the second load side heat exchanger 7, and the load side outlet temperature Tw1 of the first load side heat exchanger 4 The temperature difference with the evaporation temperature ET1 of the first load side heat exchanger 4 may be 4 deg. From the figure, the COP shows that the load side outlet temperature Tw1 of the first load side heat exchanger 4 is equal to the load side inlet temperature Tw0 of the first load side heat exchanger 4 and the load side outlet temperature Tw2 of the second load side heat exchanger 7. It shows that the maximum value (maximum value) A is reached when the arithmetic average value is obtained. This is because when the load side outlet temperature Tw1 of the first load side heat exchanger 4 is increased, the evaporation temperature ET1 of the first load side heat exchanger 4 is increased and the COP is increased. This is because the heat exchange amount of the heat exchanger 4 is reduced, and the COP of the entire system is controlled by the evaporation temperature ET2 of the second load side heat exchanger 7. Therefore, the target value Tw1m of the load side outlet temperature of the first load side heat exchanger 4 is the load side inlet temperature Tw0 of the first load side heat exchanger 4 and the load side outlet temperature Tw2 of the second load side heat exchanger 7. If the arithmetic average value Tw1m = ((Tw0 + Tw2) / 2), it indicates that efficient operation is possible.

  In the heating operation, the four-way valve 8, the first three-way valve 9, and the second three-way valve 10 are connected as indicated by dotted lines, and the on-off valve 12 is opened. Further, the ejector 3 does not perform the power recovery operation unlike the cooling operation, and functions as a simple throttle device. At this time, the refrigerant discharged from the compressor 1 passes through the gas-liquid separator 5 and the on-off valve 12 through the four-way valve 8 (the throttle device 6 is bypassed at this time), and the refrigerant that has passed through the on-off valve 12 is By radiating heat with the second load side heat exchanger 7, the medium to be heated (water or the like) is heated and cooled / liquefied to become a gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant passes through the second three-way valve 10 (first connection port 10a, second connection port 10c), and the first three-way valve 9 (third connection port 9c, second connection port 9a). By flowing into the load-side heat exchanger 4 and radiating heat from the first load-side heat exchanger 4, the medium to be heated (such as water) is heated and cooled / liquefied to become a liquid refrigerant. The liquid refrigerant that has flowed out of the first load side heat exchanger 4 is depressurized by the ejector 3, evaporates in the heat source side heat exchanger 2, and returns to the compressor 1 through the four-way valve 8.

  During the heating operation, the control means 31 controls the rotation speed of the compressor 1 so that the load-side outlet temperature Tw2 of the second load-side heat exchanger 7 becomes the target temperature Tw2m, and the outlet superheat degree of the heat-source-side heat exchanger 2 The throttle opening degree of the ejector 3 is controlled so that SH becomes the target outlet superheat degree SHm. The outlet superheat degree SH of the heat source side heat exchanger 2 is the same as that of the first embodiment if temperature detecting means (not shown) and pressure detecting means (not shown) installed at the outlet of the heat source side heat exchanger 2 are used. The same calculation can be performed. That is, the calculation of the outlet superheat degree SH of the heat source side heat exchanger 2 is performed by calculating the outlet temperature of the heat source side heat exchanger 2 (for example, a temperature detecting means provided at the outlet of the heat source side heat exchanger 2 and detecting the temperature of this temperature detecting means. ) And the inlet temperature (for example, a temperature detecting means is provided at the inlet of the heat source side heat exchanger 2 and the temperature detected by the temperature detecting means) (SH = outlet temperature−inlet temperature), or A temperature detection means and a pressure detection means (for example, a pressure sensor) are provided at the outlet portion of the heat source side heat exchanger 2, and the saturation temperature ETP obtained from the detected value P from the pressure sensor and the outlet portion of the heat source side heat exchanger 2 What is necessary is just to obtain | require as a difference (SH = ET-ETp) with the exit temperature ET detected by the temperature detection means.

  Although the first three-way valve 9 is used as the first flow path switching valve 9 and the second three-way valve 10 is used as the second flow path switching valve 10 in the present embodiment, the present invention is not limited to this. As a flow path switching valve, two on-off valves may be used in place of the three-way valves 9 and 10, or a combination of one on-off valve and one check valve 1 has the same function. And effects can be obtained.

  As mentioned above, in this Embodiment, the flow direction of the refrigerant | coolant in the heat source side heat exchanger 2 is changed by providing the four-way valve 8 between the compressor 1 and the heat source side heat exchanger 2, and switching a refrigerant flow path. When the first load side heat exchanger 4 and the second load side heat exchanger 7 are used as evaporators for evaporating the refrigerant (cooling operation or refrigeration operation) by reversing, they are used as a condenser for condensing the refrigerant. Since it is possible to switch between the cases of heating (such as heating operation), the cooling (or freezing) operation and the heating operation can be switched with a simple configuration.

  In the present embodiment, in the refrigeration cycle apparatus capable of switching between the cooling operation and the heating operation, the number of rotations of the compressor 1, the throttle opening of the ejector 3, and the throttle opening of the expansion device 6 are adjusted during the cooling operation. Thus, the state of the evaporation capacity Q1 of the first load side heat exchanger 4, the evaporation capacity Q2 of the second load side heat exchanger 7, and the outlet superheat degree (SH) of the second load side heat exchanger are appropriately controlled. It is possible to appropriately control the evaporation capacities of the two evaporators having different evaporation temperatures. In addition, during the heating operation, the ejector 3 can be operated as a simple expansion device, and a refrigerating cycle device capable of switching between the cooling operation and the heating operation with a simple configuration without requiring a separate expansion device for the heating operation is provided. be able to.

  From the above, in the present embodiment, the compressor 1, the four-way valve 8, the heat source side heat exchanger 2, the throttle opening variable ejector 3, the first load side heat exchanger 4, the gas-liquid separator 5, and the four-way valve. Refrigeration cycle in which the gas-liquid separator 5 is connected to the suction part side of the ejector 3 via the expansion device 6 and the second load side heat exchanger 7, A first flow path switching valve 9 having a connection port 9a, a second connection port 9b, and a third connection port 9c, and a second flow path switching having a first connection port 10a, a second connection port 10b, and a third connection port 10c. The first connection port 9a of the first flow path switching valve 9 is connected to the first load-side heat exchanger 4, and the second connection port 9b of the first flow path switching valve 9 is gas-liquid separated. The third connection port 9c of the first flow path switching valve 9 is connected to the third connection port 10c of the second flow path switching valve 10, and the second flow path switching valve 10 is connected. The first connection port 10 a is connected to the second load side heat exchanger 7, the second connection port 10 b of the second flow path switching valve 10 is connected to the suction portion side of the ejector 3, and the second flow path switching valve 10 The third connection port 10c is connected to the third connection port 9c of the first flow path switching valve 9, and during the cooling operation, the first flow path switching valve 9 communicates the first connection port 9a and the second connection port 9b, The second flow path switching valve 10 communicates the first connection port 10a and the second connection port 10b. During heating operation, the first flow path switching valve 9 communicates the first connection port 9a and the third connection port 9c, Since the second flow path switching valve 10 communicates the first connection port 10a and the third connection port 10c, the four-way valve 8, the first flow path switching valve 9, and the second flow path switching valve 10 can be switched. It is possible to provide a refrigeration cycle apparatus capable of easily switching between cooling operation and heating operation.

  FIG. 11 is a schematic diagram showing another configuration of the refrigeration cycle apparatus according to Embodiment 3 of the present invention. In FIG. 11, the same parts as those in the first embodiment, the second embodiment, and FIGS. 1 to 10 are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 11, the refrigeration cycle apparatus in the present embodiment is a refrigeration cycle apparatus that can be switched between a cooling operation and a heating operation, and includes a compressor 1, a four-way valve 8, a heat source side heat exchanger 2, a throttle opening degree. Changeable ejector 3, first load side heat exchanger 4, gas-liquid separator 5, expansion device 6, second load side heat exchanger 7, first three-way valve 9 (first connection port 9a, second connection Port 9b and third connection port 9c), second three-way valve 10 (having first connection port 10a, second connection port 10b and third connection port 10c), and piping for connecting them. ing.

  In the refrigeration cycle apparatus in the present embodiment, a refrigeration cycle that can be used as an accumulator that stores excess refrigerant during heating of the gas-liquid separator 5 is configured, and the liquid refrigerant returns to the compressor 1 without providing an additional accumulator. A phenomenon (liquid back) can be suppressed, and a low-cost and highly reliable refrigeration cycle apparatus can be obtained. In the figure, a four-way valve 8 is connected to the discharge part of the compressor 1, and during cooling operation, the first flow path switching valve 9 (first three-way valve 9) has a first connection port 9a connected to the four-way valve 8, and a second The connection port 9b is connected to the outlet portion of the first load side heat exchanger 4, and the second flow path switching valve 10 (second three-way valve 10) has the first connection port 10a as the outlet of the second load side heat exchanger 7. The second connection port 10 b is connected to the suction part of the ejector 3. For heating operation, the first flow path switching valve 9 (first three-way valve 9) has a first connection port 9a connected to the four-way valve 8, and a third connection port 9c connected to the expansion device 6 and the first load side. The second flow path switching valve 10 (second three-way valve 10) is connected to the outlet portion of the second load side heat exchanger 7, and is connected to the outlet portion of the heat exchanger 7. The third connection port 10 c is connected between the first load side heat exchanger 4 and the second connection port 9 b of the first flow path switching valve 9. Accordingly, during the heating operation, the gas-liquid separator 5 is connected to the suction side of the compressor 1, so that the gas-liquid separator 5 functions as an accumulator (excess refrigerant reservoir).

  Next, the driving operation will be described. The refrigeration cycle apparatus according to the present embodiment is installed outside a room, for example, and operates as a heat pump type cold / hot water supply apparatus that feeds cold water or hot water to indoor units provided indoors and cools or heats the room. In the cooling operation, the four-way valve 8, the first three-way valve 9, and the second three-way valve 10 are connected as indicated by solid line arrows. At this time, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows through the four-way valve 8 as shown by a solid line and flows into the heat source side heat exchanger 2. The liquid refrigerant condensed and liquefied by the heat source side heat exchanger 2 is decompressed by the ejector 3 to become a low temperature / low pressure gas / liquid two-phase refrigerant and flows into the first load side heat exchanger 4. The gas-liquid two-phase refrigerant in which a part of the liquid refrigerant has evaporated in the first load side heat exchanger 4 passes through the first three-way valve 9 (second connection port 9b, first connection port 9a) and the four-way valve 8, It flows into the gas-liquid separator 5. Of the gas-liquid two-phase refrigerant that has flowed into the gas-liquid separator 5, the gas refrigerant is sucked into the compressor 1, and the liquid refrigerant is decompressed by the expansion device 6 and flows into the second load-side heat exchanger 7, and the second The three-way valve 10 (first connection port 10a, second connection port 10b) is sucked into the suction portion of the ejector 3. Since the control operations of the compressor 1, the ejector 3, and the expansion device 6 during the cooling operation are the same as those in FIGS. 1 and 9, detailed description thereof is omitted.

  In the heating operation, the four-way valve 8, the first three-way valve 9, and the second three-way valve 10 are connected as indicated by dotted arrows, and the expansion device 6 is fully closed. Further, the ejector 3 does not perform a power recovery operation and functions as a simple throttle device. At this time, the refrigerant discharged from the compressor 1 flows in the order of the four-way valve 8 and the first three-way valve 9 (first connection port 9a, second connection port 9c), and the expansion device 6 is fully closed. It flows into the second load side heat exchanger 7. The refrigerant that has flowed into the second load side heat exchanger 7 radiates heat in the second load side heat exchanger 7 to heat the medium to be heated, and is cooled and liquefied to be in a gas-liquid two-phase state. This gas-liquid two-phase refrigerant flows into the first load side heat exchanger 4 through the second three-way valve 10 (first connection port 10a, third connection port 10c), and in the first load side heat exchanger 4, The medium to be heated is radiated to heat the medium to be heated, cooled and liquefied to become liquid refrigerant. The liquid refrigerant that has flowed out of the first load side heat exchanger 4 is decompressed by the ejector 3, evaporates in the heat source side heat exchanger 2, and returns to the compressor 1 through the four-way valve 8 and the gas-liquid separator 5.

  As described above, in the present embodiment, the compressor 1, the four-way valve 8, the heat source side heat exchanger 2, the throttle opening variable ejector 3, the first load side heat exchanger 4, the four-way valve 8, the gas-liquid separator. Refrigeration cycle in which the gas-liquid separator 5 is connected to the suction portion side of the ejector 3 via the expansion device 6 and the second load side heat exchanger 7, A first flow path switching valve 9 having a connection port 9a, a second connection port 9b, and a third connection port 9c, and a second flow path switching having a first connection port 10a, a second connection port 10b, and a third connection port 10c. A first connection port 9a of the first flow path switching valve 9 is connected to the four-way valve 8, and a second connection port 9b of the first flow path switching valve 9 is connected to the first load side heat exchanger. 4, the third connection port 9 c of the first flow path switching valve 9 is connected between the expansion device 6 and the second load side heat exchanger 7, and the second flow path switching valve 1 is connected. The first connection port 10a is connected to the second load side heat exchanger 7, the second connection port 10b of the second flow path switching valve 10 is connected to the suction portion side of the ejector 3, and the second flow path switching valve 10 is connected. The third connection port 10c is connected between the first load side heat exchanger 4 and the second connection port of the first flow path switching valve 9, and during the cooling operation, the first flow path switching valve 9 is connected to the first connection port 10c. The port 9a communicates with the second connection port 9b, the second flow path switching valve 10 communicates with the first connection port 10a and the second connection port 10b, and the first flow path switching valve 9 is connected to the first connection during heating operation. Since the port 9a communicates with the third connection port 9c, and the second flow path switching valve 10 communicates with the first connection port 10a and the third connection port 10c, the four-way valve 8, the first flow path switching valve 9 A refrigeration cycle apparatus that can easily switch between the cooling operation and the heating operation by switching the second flow path switching valve 10 can be provided.

  Further, during the cooling operation, by controlling the rotation speed of the compressor 1, the throttle opening of the ejector 3, and the throttle opening of the expansion device 6, the evaporation capacity ET1 and the second load side of the first load side heat exchanger 4 are controlled. By properly controlling the evaporation capacity ET2 of the heat exchanger 7 and the state of the outlet superheat degree SH of the second load side heat exchanger, the evaporation capacity of the two evaporators having different evaporation temperatures is appropriately controlled according to the load. can do. Further, during heating operation, the ejector 3 can be operated as a simple expansion device, and a simple refrigeration cycle device that does not require a separate expansion device for heating operation can be provided.

  In addition, by switching the refrigerant flow paths of the four-way valve 8, the first three-way valve 9, and the second three-way valve 10 and reversing the flow direction of the refrigerant in the heat source side heat exchanger 2, the gas-liquid separator 5 during heating operation. Is used as an accumulator that suppresses liquid back to the compressor 1, so the gas-liquid separator 5 can be used as an accumulator during heating, and the liquid back strength to the compressor 1 is improved without providing a separate accumulator. In addition, a highly reliable refrigeration cycle apparatus can be obtained at low cost.

  Although the first three-way valve 9 is used as the first flow path switching valve 9 and the second three-way valve 10 is used as the second flow path switching valve 10 in the present embodiment, the present invention is not limited to this. As a flow path switching valve, two on-off valves may be used in place of the three-way valves 9 and 10, or a combination of one on-off valve and one check valve 1 has the same function. And effects can be obtained. FIG. 12 is a view for explaining another embodiment of the first flow path switching valve 9, and FIG. 12 (a) is a schematic view when two on-off valves (solenoid valves) are used, and FIG. ) Is a schematic view when one on-off valve and one check valve are used in combination. The first connection port 9a, the second connection port 9b, and the third connection port 9c in FIG. 12 are the first connection ports 9a of the first flow path switching valve (first three-way valve) 9 described in FIG. 9 and FIG. It corresponds to the second connection port 9b and the third connection port 9c, respectively.

  In FIG. 12A, the first connection port 9a, the second connection port 9b, and the third connection port 9c are connected by a branch portion 9d, and the on-off valve (electromagnetic valve) 51 is connected to the second connection port 9b. 9d, and an open / close valve (solenoid valve) 52 is provided between the third connection port 9c and the branching portion 9d. In FIG. 12B, the first connection port 9a, the second connection port 9b, and the third connection port 9c are connected by a branch portion 9d, and the check valve 53 is connected to the second connection port 9b and the branch portion 9d. An on-off valve (solenoid valve) 52 is provided between the third connection port 9c and the branching portion 9d. Even in this case, the same functions and effects as those of the first flow path switching valve 9 can be obtained by performing the opening / closing control of the opening / closing valves 51, 52. In addition, when the check valve 53 is used instead of the solenoid valve 51, an electromagnetic coil portion of the solenoid valve 51 is not required, and the cost can be reduced. Here, the example in which the on-off valves 51 and 52 and the check valve 53 in FIG. 12 are used instead of the first flow path switching valve 9 has been described, but the on-off valve 51 in FIG. 12 is used in place of the second flow path switching valve. , 52, and the use of the check valve 53, the same function and effect can be obtained.

  In the present embodiment, an example in which R410A that can use a large pressure difference between a high pressure and a low pressure is used as the HFC-based refrigerant has been shown, but the same effect is exhibited even if R407C or R404A is used. It is also effective for propane (R290) and isobutane (R600a), which are hydrocarbon (HC) refrigerants, and particularly for carbon dioxide (CO2), adiabatic heat drop (enthalpy during isentropic expansion and enthalpy during isoenthalpy expansion) Difference) and a great effect when using the ejector, and an energy-saving refrigeration cycle apparatus can be provided.

It is a schematic diagram which shows the structure of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a figure showing the structure of the ejector used for the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention, and the relationship of a pressure change. It is a figure showing the relationship between the pressure of the refrigeration cycle apparatus showing Embodiment 1 of this invention, and enthalpy. It is a control flow figure of the refrigerating cycle device showing Embodiment 1 of the present invention. It is a figure which shows the relationship between the evaporation capability and evaporation temperature in the 1st load side heat exchanger in the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is another control flowchart of the refrigeration cycle apparatus showing Embodiment 1 of this invention. It is a figure which shows the relationship between the suction | inhalation flow volume and pressure difference of the ejector of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the refrigerating-cycle apparatus showing Embodiment 2 of this invention. It is a schematic diagram which shows the structure of the refrigerating-cycle apparatus which concerns on Embodiment 3 of this invention. It is a figure showing the relationship between the coefficient of performance (COP) of the refrigerating-cycle apparatus which concerns on Embodiment 3 of this invention, and the load side exit temperature of the 1st load side heat exchanger. It is a schematic diagram which shows another structure of the refrigerating-cycle apparatus which concerns on Embodiment 3 of this invention. It is a figure for demonstrating another Example of the flow-path switching valve of the refrigerating-cycle apparatus which concerns on Embodiment 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Heat source side heat exchanger, 3 Ejector, 1st load side heat exchanger, 5 Gas-liquid separator, 6 Throttle device, 7 2nd load side heat exchanger, 8 Four-way valve, 9 1st flow Path switching valve, 10 second flow path switching valve, 11 outdoor fan, 12 on-off valve, 21 first temperature detection means, 22 second temperature detection means, 23 third temperature detection means, 24 fourth temperature detection means, 25 5 temperature detection means, 26 6th temperature detection means, 31 control means, 41 electromagnetic coil section, 42 needle section, 43 nozzle section, 43a decompression section, 43b divergent section, 44 pressure recovery section, 45 diffuser section, 51, 52 open / close Valve, 53 Check valve, 100 Outdoor unit, 101, 102 Indoor unit.

Claims (5)

A compressor, a four-way valve, a heat source side heat exchanger, an ejector equipped with a throttle mechanism, a first load side heat exchanger, and a gas-liquid separator are connected in order, and the gas-liquid separator is connected to a throttle device and a second load. Connected to the suction part side of the ejector via a side heat exchanger, by reversing the flow direction of the refrigerant in the heat source side heat exchanger by switching the four-way valve, the first load side heat exchanger, The second load side heat exchanger can be switched between the case where it is used as an evaporator for evaporating the refrigerant and the case where it is used as a condenser for condensing the refrigerant, and the heater is operated as a simple throttle device during heating operation. A refrigeration cycle is provided, and the cooling medium flows in series in the order of the first load side heat exchanger and the second load side heat exchanger, and the cooling medium outlet of the first load side heat exchanger. Temperature, second load The cooling medium outlet temperature of the heat exchanger is detected, and the cooling medium outlet temperature of the first load side heat exchanger and the cooling medium outlet temperature of the second load side heat exchanger are the target temperatures. The refrigeration cycle apparatus is characterized in that the number of rotations of the compressor and the throttle opening of the throttle mechanism are controlled. Compressor, the heat source-side heat exchanger, et injectors, the first load-side heat exchanger, the gas-liquid separator, sequentially with connecting the gas-liquid separator throttle device, via a second load-side heat exchanger The cooling medium flows in series in the order of the refrigeration cycle configured to be connected to the suction portion side of the ejector, the first load side heat exchanger, and the second load side heat exchanger, and the first load A temperature detecting means for detecting a cooling medium inlet temperature of the side heat exchanger, a temperature detecting means for detecting a cooling medium outlet temperature of the first load side heat exchanger, and a temperature detection means of the second load side heat exchanger. Temperature detection means for detecting a cooling medium outlet temperature, and a target temperature of a cooling medium outlet temperature of the first load side heat exchanger is set to a cooling medium inlet temperature of the first load side heat exchanger and the first temperature. Arithmetic average value of the cooling medium outlet temperature of the two load side heat exchanger and the first load Refrigerating cycle apparatus characterized by the coolant outlet temperature of the heat exchanger is so controlled to be the target temperature. When the refrigerant flowing in the refrigeration cycle is depressurized, the ejector includes a suction unit that sucks the refrigerant in the refrigeration cycle due to a pressure difference, a refrigerant decompressed by the throttling unit, and a refrigerant sucked by the suction unit. comprising a mixing unit to be mixed, the refrigeration cycle apparatus according to claim 1 or claim 2, characterized in that to enable changing the throttle opening degree. By switching the refrigerant flow path by providing a four-way valve between the compressor and the heat source side heat exchanger, by reversing the flow direction of the refrigerant in the heat source side heat exchanger, the first load side heat exchanger, the second load-side heat exchanger, according to claim 2 or claims, characterized in that to enable switching between the case of using as a condenser for condensing the refrigerant when used as an evaporator for evaporating the refrigerant Item 4. The refrigeration cycle apparatus according to Item 3 . The gas-liquid separator is used as an accumulator for suppressing liquid back to the compressor during heating operation by switching the refrigerant flow path by the four-way valve and reversing the flow direction of the refrigerant in the heat source side heat exchanger. The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein the refrigeration cycle apparatus is configured as described above.

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