JP2007212103A - Heat pump type hot water supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type hot water supply apparatus capable of securing reliability of a compressor by preventing sudden change of a refrigerating cycle even when there is sudden change of a hot water supply capacity and sudden change of a water supply temperature, and preventing an abnormal temperature rise and an abnormal pressure rise of the compressor. <P>SOLUTION: The heat pump type hot water supply apparatus is provided with a heat pump cycle comprised by annularly connecting the compressor 11, a hot water supply heat exchanger 12, a pressure reducing device 13, and a heat source heat exchanger 14 in sequence by a coolant pipe arrangement 15, a hot water supply cycle comprised by annularly connecting a hot water storage tank 16 storing liquid for hot water supply, a transfer means 17 for circulating the liquid of the hot water storage tank 16, and the hot water supply heat exchanger 12 in sequence by a liquid pipe arrangement 18, a thermistor 31 detecting a temperature of a coolant delivered from the compressor 11, and a control means 30 from controlling a valve opening of the pressure reducing device 13 such that the temperature detected by the thermistor 31 becomes a predetermined temperature. It is characterized by that, when there is sudden change of an operation frequency of the compressor 11, the valve opening of the pressure reducing device 13 is changed to a preset opening. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention prevents the sudden change of the refrigeration cycle even if the hot water supply capacity or the supply water temperature changes suddenly, and realizes an efficient hot water supply heating operation without an abnormal temperature rise and abnormal pressure rise of the compressor, thereby improving the reliability of the compressor. It is related with the heat pump type hot water heater which secured.

Conventionally, the opening degree of the decompression device is controlled so that the discharge refrigerant temperature of the compressor becomes a target discharge refrigerant temperature that is set in advance with respect to the outside air temperature, and the dead zone in which the opening degree of the decompression device is made constant at startup It had time (for example, refer to Patent Document 1).
JP 2000-346449 A

  However, heat pump water heaters can cause abnormal compressor temperature rises and pressure rises when the hot water supply capacity changes or the temperature of the water supplied to the hot water heat exchanger changes suddenly. However, has a problem that the predetermined temperature cannot be maintained.

  The present invention solves the above-mentioned conventional problems, and prevents a sudden change in the refrigeration cycle even during a sudden change in hot water supply capacity and a sudden change in feed water temperature, thereby preventing an abnormal temperature rise and abnormal pressure rise in the compressor. It aims at providing the heat pump type hot water heater which can ensure the reliability of a machine.

  In order to solve the above-described conventional problems, the heat pump type hot water heater of the present invention includes a heat pump cycle in which a compressor, a hot water heat exchanger, a pressure reducing device, and a heat source heat exchanger are sequentially connected in an annular manner through a refrigerant pipe. A hot water storage tank for storing liquid for hot water supply, a conveying means for circulating the liquid in the hot water storage tank, a hot water supply cycle in which the heat exchanger for hot water supply is sequentially connected in an annular manner by a liquid pipe, and discharged from the compressor Discharge refrigerant temperature detection means for detecting the temperature of the refrigerant, and control means for controlling the valve opening of the decompression device so that the temperature detected by the discharge refrigerant temperature detection means becomes a predetermined temperature, When is changed, the operating frequency of the compressor and the valve opening of the pressure reducing device are changed to a preset opening.

  As a result, even if the operating frequency of the compressor suddenly changes due to a change in hot water supply capacity, sudden changes in the refrigeration cycle can be prevented, abnormal temperature rise and abnormal pressure rise of the compressor can be prevented. While ensuring reliability, a predetermined boiling temperature can be maintained.

  The heat pump type hot water heater of the present invention includes a heat pump cycle in which a compressor, a heat exchanger for hot water supply, a pressure reducing device, and a heat exchanger for heat source are sequentially connected in an annular manner by a refrigerant pipe, and a hot water storage for storing a liquid for hot water supply. A tank, a conveying means for circulating the liquid in the hot water tank, a hot water supply cycle in which the hot water heat exchanger is sequentially connected in an annular manner by a liquid pipe, and a discharge refrigerant for detecting the temperature of the refrigerant discharged from the compressor Temperature detection means, control means for controlling the valve opening of the pressure reducing device so that the temperature detected by the discharged refrigerant temperature detection means becomes a predetermined temperature, and water supplied to the hot water supply heat exchanger A feed water temperature detecting means for detecting the temperature, and when the temperature detected by the feed water temperature detecting means changes more than a predetermined temperature within a predetermined time, the operating frequency of the compressor and the opening of the pressure reducing device are preset. It is characterized in that the change in opening degree.

  This makes it possible to prevent sudden changes in the refrigeration cycle even when the feed water temperature to the heat exchanger for hot water supply changes suddenly, to prevent abnormal temperature rises and abnormal pressure rises in the compressor, and the reliability of the compressor It is possible to maintain the predetermined boiling temperature while securing the property.

  A heat pump water heater that prevents the sudden change of the refrigeration cycle and prevents the abnormal temperature rise and abnormal pressure rise of the compressor even when the hot water supply capacity suddenly changes and the water supply temperature suddenly changes. Can be provided.

  A first aspect of the present invention is a heat pump cycle in which a compressor, a hot water supply heat exchanger, a decompression device, and a heat source heat exchanger are sequentially connected in an annular manner through a refrigerant pipe, a hot water storage tank for storing hot water supply liquid, and the hot water storage tank Conveying means for circulating the liquid therein, a hot water supply cycle in which the hot water supply heat exchanger is sequentially connected in an annular manner by liquid piping, and a discharge refrigerant temperature detection means for detecting the temperature of the refrigerant discharged from the compressor, Control means for controlling the valve opening of the pressure reducing device so that the temperature detected by the discharged refrigerant temperature detecting means becomes a predetermined temperature, and when the hot water supply capacity changes, the operating frequency of the compressor and the By changing the valve opening of the decompression device to a preset opening, even if the operating frequency of the compressor suddenly changes due to a change in hot water supply capacity, sudden changes in the refrigeration cycle can be prevented. By preventing the temperature rise and abnormal pressure increase, it is possible to ensure the reliability of the compressor can be maintained a predetermined boiling temperature.

  According to a second aspect of the present invention, there is provided a heat pump cycle in which a compressor, a hot water supply heat exchanger, a pressure reducing device, and a heat source heat exchanger are sequentially connected in an annular manner through a refrigerant pipe, a hot water storage tank for storing hot water supply liquid, and the hot water storage tank Conveying means for circulating the liquid therein, a hot water supply cycle in which the hot water supply heat exchanger is sequentially connected in an annular manner by liquid piping, and a discharge refrigerant temperature detection means for detecting the temperature of the refrigerant discharged from the compressor, Control means for controlling the valve opening of the decompression device so that the temperature detected by the discharged refrigerant temperature detection means becomes a predetermined temperature, and water supply for detecting the temperature of water supplied to the hot water supply heat exchanger A temperature detecting means, and when the temperature detected by the feed water temperature detecting means changes more than a predetermined temperature within a predetermined time, the operating frequency of the compressor and the opening of the pressure reducing device are set to a preset opening. To change Therefore, even if the feed water temperature to the hot water supply heat exchanger suddenly changes, it is possible to prevent a sudden change in the refrigeration cycle, and to ensure the reliability of the compressor by preventing the abnormal temperature rise and abnormal pressure rise of the compressor. At the same time, a predetermined boiling temperature can be maintained.

  In a third aspect of the invention, particularly in the first or second aspect of the invention, the valve opening of the pressure reducing device is kept constant for a predetermined time after the valve opening of the pressure reducing device is changed to a preset opening. And after the predetermined time has elapsed, the valve opening degree of the pressure reducing device is controlled so that the discharge refrigerant temperature of the compressor becomes a preset target discharge refrigerant temperature, so that the dead time of the valve opening degree of the pressure reducing device is reached. Therefore, it is possible to prevent overshoot of the refrigerant discharge pressure of the compressor by waiting for the delay of the temperature rise with respect to the pressure in the transient state, and to prevent the sudden change of the refrigeration cycle. An increase in temperature and abnormal pressure can be prevented more reliably, and the reliability of the compressor can be improved.

  According to a fourth aspect of the present invention, in particular, in any one of the first to third aspects, since the compressor has a configuration without an accumulator, the main body of the heat pump type hot water heater can be reduced in size and weight.

According to a fifth aspect of the invention, in any one of the first to fourth aspects of the invention, the heat pump cycle is a supercritical heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure. Since the refrigerant is pressurized to a critical pressure or higher, it does not condense even if the temperature is lowered due to heat deprived by the water in the hot water heat exchanger, and the refrigerant and water are not condensed in the entire area of the hot water heat exchanger. It is easy to form a temperature difference between them, high-temperature hot water can be obtained, and heat exchange efficiency can be increased.

  According to a sixth invention, in particular, in any one of the first to fifth inventions, since the refrigerant is carbon dioxide, the product cost can be suppressed and the reliability can be improved, the ozone depletion coefficient is zero, the earth Since the global warming potential is very small, about 1700 of the alternative refrigerant HFC-407C, a product that is friendly to the global environment can be provided.

  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.

(Embodiment 1)
FIG. 1 and FIG. 2 are a configuration diagram and an operation control diagram of the heat pump type hot water heater in the first embodiment of the present invention. In FIG. 1, the heat pump type hot water heater of the present invention includes a heat pump cycle in which a compressor 11, a heat source machine heat exchanger 14, a pressure reducing device 13, and a hot water supply heat exchanger 12 are sequentially connected in an annular manner by a refrigerant pipe 15, and a conveying means A hot water supply cycle in which the water pump 17, the hot water supply heat exchanger 12, and the hot water storage tank 16 are sequentially connected in an annular manner by a liquid pipe 18, and discharge refrigerant temperature detection means for detecting the discharge refrigerant temperature of the refrigerant discharged from the compressor 11. A certain thermistor 31, a pressure reducing device control means 34 that is a control means for controlling the valve opening degree of the pressure reducing device 13 so that the thermistor 31 reaches a predetermined temperature, and the temperature of water supplied to the hot water supply heat exchanger 12 are set. Desired hot water supply capacity instructed from the hot water storage tank 16 by the thermistor 33 that is the detected water temperature detection means and the microcomputer 32 that is the hot water supply capacity instruction detection means. It controls the operating frequency of the compressor 11 so as to constituted the compressor operation frequency control means 35. The decompression device control means 34 and the compressor operating frequency control means 35 are constituted by a microcomputer 30. The decompression device 13 uses an electric expansion valve. Moreover, in the hot water supply heat exchanger 12, the refrigerant and water exchange heat with each other.

  The microcomputer 32 detects the optimum hot water supply capacity from the amount of hot water stored in the hot water tank, the amount used, the boiling temperature, and the like, and instructs the microcomputer 30 that controls the heat pump cycle of the hot water supply capacity. In the present embodiment, the microcomputer 32 that is the hot water supply capacity instruction detection means is described as a separate body from the microcomputer 30 that controls the equipment constituting the heat pump cycle, but is not limited thereto. For example, in an integrated heat pump cycle in which a hot water supply cycle and a heat pump cycle are integrally configured, the microcomputer 30 and the microcomputer 32 may be configured by the same microcomputer.

  The operation and action of the heat pump type water heater configured as described above will be described below.

  FIG. 3 is a flowchart showing the operation in the present embodiment. In FIG. 3, the microcomputer 32 detects a hot water supply capacity change instruction from the hot water storage tank 16, determines the operating frequency of the compressor 11 so that the changed hot water supply capacity is obtained, and the compressor operating frequency control means 35 The operating frequency is changed. Moreover, the valve opening degree of the decompression device 13 preset by the hot water supply capability is determined, and the valve opening degree is shifted. Then, after the shift, the valve opening degree of the decompression device 13 is further controlled by the decompression device control means 34 so that the desired discharge refrigerant temperature is obtained.

FIG. 4 is a diagram comparing the present embodiment with the prior art. In FIG. 4, the present embodiment is indicated by a solid line, and the prior art is indicated by a dotted line. According to this, it can be seen that the operating frequency of the compressor is suddenly changed when the hot water supply capacity is changed. At the same timing that this operating frequency suddenly changes,
The valve opening degree of the pressure reducing device is shifted to a valve opening degree set in advance according to the hot water supply capacity, and then the valve opening degree is controlled so as to reach a desired discharge refrigerant temperature. The desired discharge refrigerant temperature here is a target value of the discharge refrigerant temperature that is appropriately determined according to the boiling temperature (temperature discharged from the hot water supply heat exchanger), and is higher than the boiling temperature. It is preferable to set. As a result, in the prior art, overshoot of discharge refrigerant pressure, discharge refrigerant temperature, and boiling temperature occurred, but it can be seen that overshoot can be prevented by controlling as in this embodiment. . Therefore, it is possible to shift the hot water supply capacity while keeping the refrigeration cycle stable, and even if the hot water supply capacity changes and the operating frequency of the compressor 11 changes suddenly, the sudden change of the refrigeration cycle can be prevented. By preventing the abnormal temperature rise and the abnormal pressure rise, the reliability of the compressor 11 can be ensured and a predetermined boiling temperature can be maintained.

  Moreover, in this Embodiment, since the compressor 11 is set as the structure without an accumulator, size reduction and weight reduction of a heat pump type water heater main body are attained. Furthermore, carbon dioxide is used as the refrigerant of the heat pump cycle, and the refrigerant is pressurized to a critical pressure or higher in the hot water supply heat exchanger 12, so heat is taken away by the water in the hot water supply heat exchanger 12. Even if the temperature drops, it does not condense and it is easy to form a temperature difference between the refrigerant and water throughout the hot water supply heat exchanger, so that hot water is obtained and heat exchange efficiency is improved. Can be high. Furthermore, since carbon dioxide is relatively inexpensive and stable, it is possible to reduce product cost and improve reliability. In addition, since the ozone depletion coefficient is zero and the global warming coefficient is as low as about 1700 of the alternative refrigerant HFC-407C, a product that is friendly to the global environment can be provided.

(Embodiment 2)
Since the configuration of the heat pump type hot water heater in the second embodiment of the present invention is the same as that of the first embodiment, description thereof is omitted. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

FIG. 5 is an operation control diagram according to the second embodiment. In FIG. 5, when the value of the thermistor 33 that is a feed water temperature detecting means for detecting the temperature of the water flowing into the hot water supply heat exchanger changes more than a predetermined temperature within a predetermined time, the operating frequency of the compressor 11 is changed. While changing the valve opening, the valve opening is shifted to a predetermined opening according to the feed water temperature, and then the refrigerant discharge temperature detecting means 31 is controlled to a desired temperature.
FIG. 6 is a diagram comparing the present embodiment with the prior art. In FIG. 6, this embodiment is indicated by a solid line, and the prior art is indicated by a dotted line. This shows that the operating frequency of the compressor is suddenly changed when the feed water temperature changes. At the same timing when the operating frequency suddenly changes, the valve opening of the pressure reducing device is shifted to a valve opening set in advance according to the hot water supply capacity, and then the valve is opened so that the desired discharge refrigerant temperature is reached. Control the degree. As a result, in the prior art, overshoot of discharge refrigerant pressure, discharge refrigerant temperature, and boiling temperature occurred, but it can be seen that overshoot can be prevented by controlling as in this embodiment. . Therefore, it is possible to shift the hot water supply capacity while stabilizing the refrigeration cycle, and even when the hot water supply capacity changes and the operating frequency of the compressor 11 changes suddenly, the sudden change of the refrigeration cycle can be prevented. By preventing the abnormal temperature rise and the abnormal pressure rise, the reliability of the compressor 11 can be ensured and a predetermined boiling temperature can be maintained.

Moreover, in this Embodiment, since the compressor 11 is set as the structure without an accumulator, size reduction and weight reduction of a heat pump type water heater main body are attained. Furthermore, carbon dioxide is used as the refrigerant of the heat pump cycle, and the refrigerant is pressurized to a critical pressure or higher in the hot water supply heat exchanger 12, so heat is taken away by the water in the hot water supply heat exchanger 12. Even if the temperature drops, it does not condense and it is easy to form a temperature difference between the refrigerant and water throughout the hot water supply heat exchanger, so that hot water is obtained and heat exchange efficiency is improved. Can be high. Furthermore, since carbon dioxide is relatively inexpensive and stable, it is possible to reduce product cost and improve reliability. In addition, since the ozone depletion coefficient is zero and the global warming coefficient is as low as about 1700 of the alternative refrigerant HFC-407C, a product that is friendly to the global environment can be provided.

(Embodiment 3)
Since the configuration of the heat pump type hot water heater in the third embodiment of the present invention is the same as that of the first embodiment, the description thereof is omitted. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Moreover, the flowchart which shows the operation | movement in this Embodiment is also the same as the heat pump type water heater in 1st Embodiment, and is shown in FIG.
In FIG. 3, the microcomputer 32 detects a hot water supply capacity change instruction from the hot water storage tank 16, determines the operating frequency of the compressor 11 so that the changed hot water supply capacity is obtained, and the compressor operating frequency control means 35 The operating frequency is changed. Moreover, the valve opening degree of the decompression device 13 preset by the hot water supply capability is determined, and the valve opening degree is shifted. Then, after the shift, the valve opening degree of the decompression device 13 is further controlled by the decompression device control means 34 so that the desired discharge refrigerant temperature is obtained.

  FIG. 7 is a diagram comparing the present embodiment with the prior art. In FIG. 7, the present embodiment is indicated by a solid line, and the prior art is indicated by a dotted line. According to this, it can be seen that the operating frequency of the compressor is suddenly changed when the hot water supply capacity is changed. At the same timing that the operating frequency suddenly changes, the valve opening of the pressure reducing device is shifted to a valve opening set in advance according to the hot water supply capacity, and the shifted valve opening is kept for a predetermined time. A dead-zone time that is kept constant is provided, and after a predetermined time has elapsed, the valve opening degree is controlled so as to reach a desired discharged refrigerant temperature. The desired discharge refrigerant temperature here is a target value of the discharge refrigerant temperature that is appropriately determined according to the boiling temperature (temperature discharged from the hot water supply heat exchanger), and is higher than the boiling temperature. It is preferable to set. As a result, in the prior art, overshoot of discharge refrigerant pressure, discharge refrigerant temperature, and boiling temperature occurred, but it can be seen that overshoot can be prevented by controlling as in the present embodiment. . Therefore, in order to control the valve opening degree of the pressure reducing device 13 so that the target discharge refrigerant temperature is reached after that, a dead zone time for controlling the valve opening degree to be constant is set, so that a delay in the temperature rise with respect to the pressure in the transient state is waited. Therefore, overshoot of the refrigerant pressure discharged from the compressor 11 can be prevented, and sudden change of the refrigeration cycle can be prevented. By preventing the abnormal temperature rise and abnormal pressure rise of the compressor 11 more reliably, the compressor 11 Reliability can be improved.

  Moreover, in this Embodiment, since the compressor 11 is set as the structure without an accumulator, size reduction and weight reduction of a heat pump type water heater main body are attained. Furthermore, carbon dioxide is used as the refrigerant of the heat pump cycle, and the refrigerant is pressurized to a critical pressure or higher in the hot water supply heat exchanger 12, so heat is taken away by the water in the hot water supply heat exchanger 12. Even if the temperature drops, it does not condense and it is easy to form a temperature difference between the refrigerant and water throughout the hot water supply heat exchanger, so that hot water is obtained and heat exchange efficiency is improved. Can be high. Furthermore, since carbon dioxide is relatively inexpensive and stable, it is possible to reduce product cost and improve reliability. In addition, since the ozone depletion coefficient is zero and the global warming coefficient is as low as about 1700 of the alternative refrigerant HFC-407C, a product that is friendly to the global environment can be provided.

As described above, the heat pump water heater according to the present invention includes an integrated heat pump water heater in which a heat pump cycle and a hot water cycle are integrally formed, a separate heat pump water heater configured separately, and heat exchange for hot water supply. The present invention can also be applied to a direct hot water heat pump type hot water heater that can discharge hot water heated by a bath as it is, and can also be applied to a heat pump device having a hot water bath function, a heating function, and a drying function in addition to a hot water supply function.

The block diagram of the heat pump type water heater in Embodiment 1 of this invention Operation control diagram in the same embodiment Control flow chart of heat pump type water heater in the same embodiment Comparison diagram of heat pump type water heater and conventional technology in the same embodiment Operation control diagram in Embodiment 2 of the present invention Comparison diagram of heat pump type water heater and conventional technology in the same embodiment Comparison diagram of heat pump type water heater and conventional technology in Embodiment 3 of the present invention

Explanation of symbols

11 Compressor 12 Heat exchanger for hot water supply 13 Pressure reducing device (electric expansion valve)
14 Heat exchanger for heat source 15 Refrigerant piping 16 Hot water storage tank 17 Pump (water pump)
18 Liquid piping 30 Microcomputer 31 Discharge refrigerant temperature detection means (thermistor)
32 microcomputer 33 feed water temperature detection means (thermistor)
34 Pressure reducing device control means (microcomputer 30)
35 Compressor operating frequency control means (microcomputer 30)

Claims (6)

A heat pump cycle in which a compressor, a hot water supply heat exchanger, a pressure reducing device, and a heat source heat exchanger are sequentially connected in an annular manner through a refrigerant pipe, a hot water storage tank for storing hot water supply liquid, and a liquid in the hot water storage tank are circulated Conveying means, a hot water supply cycle in which the hot water supply heat exchanger is sequentially connected in an annular manner by liquid piping, a discharge refrigerant temperature detection means for detecting the temperature of the refrigerant discharged from the compressor, and the discharge refrigerant temperature detection means Control means for controlling the valve opening of the pressure reducing device so that the temperature detected at the predetermined temperature becomes a predetermined temperature, and when the hot water supply capacity changes, the operating frequency of the compressor and the valve opening of the pressure reducing device Is changed to a preset opening, a heat pump type hot water heater. A heat pump cycle in which a compressor, a hot water supply heat exchanger, a pressure reducing device, and a heat source heat exchanger are sequentially connected in an annular manner through a refrigerant pipe, a hot water storage tank for storing hot water supply liquid, and a liquid in the hot water storage tank are circulated Conveying means, a hot water supply cycle in which the hot water supply heat exchanger is sequentially connected in an annular manner by liquid piping, a discharge refrigerant temperature detection means for detecting the temperature of the refrigerant discharged from the compressor, and the discharge refrigerant temperature detection means Control means for controlling the valve opening degree of the pressure reducing device so that the temperature detected in step 1 becomes a predetermined temperature, and water supply temperature detection means for detecting the temperature of the water supplied to the hot water supply heat exchanger. When the temperature detected by the feed water temperature detecting means changes more than a predetermined temperature within a predetermined time, the operating frequency of the compressor and the opening of the pressure reducing device are changed to a preset opening. To do Toponpu water heater. After changing the valve opening of the decompression device to a preset opening, the valve opening of the decompression device is controlled to be constant for a predetermined time, and after the predetermined time has elapsed, the discharge refrigerant temperature of the compressor The heat pump type water heater according to claim 1 or 2, wherein the valve opening degree of the pressure reducing device is controlled so as to be a preset target discharge refrigerant temperature. The heat pump type hot water heater according to any one of claims 1 to 3, wherein the compressor has a configuration without an accumulator. The heat pump water heater according to any one of claims 1 to 4, wherein the heat pump cycle is a supercritical heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure. The heat pump type hot water heater according to any one of claims 1 to 5, wherein the refrigerant is carbon dioxide.

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