JP2017133727A - Heat pump type water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type water heater capable of cooling a control device effectively by using a refrigerant in a refrigerant flow passage even during a defrosting operation.SOLUTION: A compressor 11, a condensation heat exchanger 12, an expansion valve 13, and an evaporation heat exchanger 14 are communicated sequentially by refrigerant piping 15. A heat pump type water heater includes: a bypass passage 18 for guiding a high-temperature refrigerant discharged from the compressor 11 directly to an inlet of the evaporation heat exchanger 14 by detouring the condensation heat exchanger 12 and the expansion valve 13; and a solenoid valve 19 for defrosting for switching opening/closing of the bypass passage 18. As a control device 3, a heat sink constituted by a plurality of heat radiation fins is provided at a control board in which a power module is installed in a closely contacted manner. With respect to the refrigerant piping leading from the evaporation heat exchanger to the compressor, the heat sink is installed in a state of being in contact, so as to be able to exchange heat with the refrigerant in the refrigerant piping.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat pump type hot water supply apparatus configured to heat-exchange and heat hot water for hot water supply in a condensing heat exchanger constituting a refrigeration circuit, and in particular, to cool a control device for operation control to defrost an evaporative heat exchanger. It relates to a technique that can be effectively performed even during operation.

  2. Description of the Related Art Conventionally, an air conditioner for cooling a room or the like is provided with a refrigeration cycle in which a compressor, a condensation heat exchanger, an expansion valve, and an evaporative heat exchanger are connected in order by refrigerant piping, and the air conditioner is operated and controlled. Refrigeration cycle operating efficiency is improved by arranging a part of the refrigerant piping with respect to the control device, heating the refrigerant by exchanging heat with the heat generated from the circuit components constituting the control device, and promoting the evaporation of the refrigerant It has been proposed (see, for example, paragraphs 0001 and 0023 of Patent Document 1). That is, the control board to which the circuit components of the control device are attached is arranged with respect to the refrigerant pipe extending from the outdoor condensation heat exchanger to the expansion valve (see, for example, FIG. 1 of Patent Document 1).

Japanese Patent Laid-Open No. 10-73327

  By the way, unlike an air conditioner in which the evaporative heat exchanger constituting the refrigeration cycle is arranged indoors and the heat absorbed by the evaporative heat exchanger is used for cooling, the heat radiation from the condensing heat exchanger is used for heating hot water. In a heat pump type hot water supply apparatus, when the outside air is at a low temperature, the evaporative heat exchanger installed outside the room may be frosted. When the frost is formed, the original role of the evaporative heat exchanger cannot be performed, so that the defrosting operation is performed. Usually, the refrigerant which has been heated to a high temperature and high pressure by a compressor is bypassed by a condensation heat exchanger and an expansion device and led to an outdoor evaporating heat exchanger to melt frost attached to the evaporating heat exchanger.

  However, in the case of the above-described air conditioner, when such a defrosting operation is performed, not only the refrigerant does not flow into the refrigerant pipe disposed in the control device, but the heat generation from the control device cannot be recovered, Also, the cooling of the control device by heat exchange becomes impossible. For this reason, in order to implement | achieve a defrost operation, in order to cool a control apparatus at the time of a defrost operation, it will be necessary to install means, such as a cooling fan, auxiliary.

  The present invention has been made in view of such circumstances, and the object of the present invention is a heat pump type that can effectively cool the control device using the refrigerant in the refrigerant flow path even during the defrosting operation. The object is to provide a water heater.

  In order to achieve the above object, in the present invention, a compressor, a condensation heat exchanger, an expansion valve, and a refrigeration circuit in which an evaporative heat exchanger are sequentially communicated with each other through a refrigerant flow path, and the operation of the refrigeration circuit are controlled. And the following technical means for a heat pump type hot water supply apparatus configured to be capable of heat exchange heating of hot water for hot water supply with a refrigerant discharged from the compressor in the condensation heat exchanger Took.

  That is, the refrigerant discharged from the compressor is supplied to the refrigeration circuit directly to the inlet of the evaporation heat exchanger by bypassing the condensation heat exchanger and the expansion valve, thereby removing the evaporation heat exchanger. In order to perform the frost operation, a flow path for defrosting that can be switched is provided. And the said control apparatus is equipped with the heat generating element which generate | occur | produces heat | fever with the operation | movement, The heat generating element can be heat-exchanged with the refrigerant | coolant in the refrigerant flow path with respect to the refrigerant flow path from the said evaporative heat exchanger to a compressor. It was decided to arrange (claim 1).

  In the case of the present invention, the high-temperature refrigerant compressed by the compressor is allowed to flow through the condensation heat exchanger, the refrigerant after heating and heating the hot water for hot water supply is depressurized by the expansion valve, and the evaporative heat exchanger absorbs heat from the outside air. A normal operation control for performing a refrigeration cycle operation in which the evaporated refrigerant is returned to the compressor and compressed again is executed by the control device. In this normal operation control state, the heat generating element of the control device is sufficiently cooled by heat exchange with the refrigerant in the refrigerant flow path that is vaporized by the evaporation heat exchanger and then sent to the compressor. It is possible to further heat the refrigerant before it is introduced into the compressor by causing the refrigerant to absorb the generated heat. Furthermore, even when the defrosting operation control is executed by switching the flow path to the defrosting flow path, it is introduced directly into the evaporative heat exchanger from the compressor and defrosted to the compressor. It becomes possible to cool the heat generating element of the control device by heat exchange with the refrigerant to be sent. As a result, the cooling function for the heating element of the control device during the defrosting operation can be ensured only by heat exchange with the refrigerant in the refrigerant flow path without installing a cooling fan or the like, and the size of the apparatus can be reduced. Can also be achieved. Note that the heat generating element is an element constituting the control device, and is an element that generates heat in accordance with its operation, and corresponds to, for example, an inverter device.

  In the heat pump hot water supply apparatus of the present invention, the heat generating element is provided with a heat sink, and the heat sink is arranged so as to be able to exchange heat by being arranged in contact with the refrigerant flow path from the evaporating heat exchanger to the compressor. (Claim 2). By doing in this way, the cooling function with respect to the heat generating element based on heat exchange with the refrigerant in the refrigerant channel can be surely exhibited.

  Further, in this case, a first temperature sensor for detecting the temperature of the heat sink is provided, and the operation of the compressor is controlled as a control device so that the temperature of the heat sink detected by the first temperature sensor is lower than a predetermined temperature. (Claim 3). In this way, during the defrosting operation control, even if a high-temperature refrigerant is directly supplied from the compressor to the evaporative heat exchanger through the defrosting flow path, the cooling function for the heating element of the control device is ensured. It is possible to reliably avoid the risk of damage due to overheating of the heat generating element. Also, in this case, the temperature of the refrigerant coming out of the evaporating heat exchanger is equal to the heat sink temperature because of good heat conduction, and the first temperature sensor serves as the evaporating heat exchanger outlet temperature sensor. Thus, the evaporative heat exchanger outlet temperature sensor can be omitted.

  The heat pump type hot water supply apparatus of the present invention includes a second temperature sensor for detecting the temperature of the refrigerant led out from the outlet of the evaporative heat exchanger, and the refrigerant temperature detected by the second temperature sensor as the control device is predetermined. The operation of the compressor can be controlled so as to be equal to or lower than the temperature (Claim 4). In this way, during the defrosting operation control, even if a high-temperature refrigerant is directly supplied from the compressor to the evaporative heat exchanger through the defrosting flow path, the cooling function for the heating element of the control device is ensured. It is possible to reliably avoid the risk of damage due to overheating of the heat generating element.

  As described above, according to the heat pump type hot water supply apparatus of the present invention, when the normal operation control for performing the refrigeration cycle operation is executed in the refrigeration circuit, the refrigerant sent to the compressor after being vaporized by the evaporative heat exchanger. Heat exchange with the refrigerant in the flow path can sufficiently cool the heat generating element of the control device, and the heat generated by the heat generating element is absorbed by the refrigerant to further heat the refrigerant before being introduced into the compressor. Will be able to. Furthermore, even when the defrosting operation control is executed by switching the flow path to the defrosting flow path, it is introduced directly into the evaporative heat exchanger from the compressor and defrosted to the compressor. Through heat exchange with the refrigerant to be sent, the heat generating element of the control device can be cooled. Thereby, the cooling function with respect to the heat generating element of the control device during the defrosting operation can be ensured only by heat exchange with the refrigerant in the refrigerant flow path without installing a cooling fan or the like. At the same time, the installation of means such as a cooling fan is omitted, so that compactness can be achieved.

It is a schematic diagram of the heat pump type hot water supply apparatus which concerns on embodiment of this invention. FIG. 2 is a partially enlarged perspective view in which a part of the control device of the heat pump hot water supply device of FIG. It is a related figure of heat sink temperature or the outlet temperature of an evaporative heat exchanger, and time controlled by temperature management control in defrost operation control.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a heat pump type hot water supply apparatus according to an embodiment of the present invention. This heat pump type hot water supply apparatus is a combination of a heat pump unit 1 using a refrigeration cycle and a hot water supply circuit 2, and heat exchange heats the water in the hot water supply circuit 2 using heat radiation from a condensation heat exchanger of the refrigeration cycle. It has come to be able to do. The heat pump unit 1 includes a compressor 11, a condensation heat exchanger (condenser) 12, an expansion valve 13 as a decompression means, and an evaporating heat exchanger (evaporator) 14, a refrigerant pipe constituting a refrigerant flow path. 15 are connected in order. As the refrigerant to be circulated in the heat pump unit 1, an appropriate HC refrigerant such as propane or CO 2 can be employed. The hot water supply circuit 2 includes a hot water storage tank 21, a water circulation pipe 22 for circulating hot water stored in the hot water storage tank 21 between the condensation heat exchanger 12, and water from the bottom of the hot water storage tank 21 through the water circulation pipe 22. Is supplied to the condensing heat exchanger 12 and is provided with a feed water pump 23 that leads from the condensing heat exchanger 12 to the top of the hot water storage tank 21 after heating. The operation of the heat pump unit 1 and the hot water supply circuit 2 is controlled by the control device 3 so that the water is heated to the target boiling temperature in the condensation heat exchanger 12 and stored in the hot water storage tank 21.

  The compressor 11 is operated by an electric motor, and the operation of the compressor 11 is controlled by the control device 3 with the rotation speed as an operation control amount. The number of revolutions is changed and controlled by changing the operating frequency given from the control device 3. In order to compress to a higher pressure, the rotational speed is increased, and to lower the pressure, the rotational speed is decreased. By being compressed by the compressor 11, high-temperature and high-pressure refrigerant is discharged from the compressor 11 to the refrigerant pipe 15, the discharge temperature is detected by the discharge temperature sensor 16, and the detected discharge temperature is output to the control device 3. Will be.

  The condensation heat exchanger 12 is configured such that a part of the refrigerant pipe 15 is passed through the interior, and a part of the water circulation pipe 22 is passed through the interior from the opposite direction to exchange heat therebetween. That is, the high-temperature refrigerant discharged from the compressor 11 to the refrigerant pipe 15 and the water supplied from the bottom of the hot water storage tank 21 by the water supply pump 23 are subjected to heat exchange, and the water is converted into hot water by heat exchange heating. The refrigerant whose heat has been removed by the exchange condenses.

  The expansion valve 13 depressurizes the refrigerant from the condensation heat exchanger 12. The operation of the expansion valve 13 is controlled by the control device 3 using the opening degree as an operation control amount.

  The evaporative heat exchanger 14 includes a fan 14a that blows outside air by its rotation operation, and heat exchange is performed between the outside air and the refrigerant decompressed by the expansion valve 13, thereby evaporating the refrigerant and converting it into a gas phase state. (Vaporization). The refrigerant temperature leaving the evaporating heat exchanger 14 is detected by a heat sink temperature sensor 17 described later, and the detected heat sink temperature (= evaporating heat exchanger outlet temperature) is output to the control device 3. Then, the refrigerant exiting the evaporative heat exchanger 14 exchanges heat with the control device 3 and then returned to the compressor 11, and is again compressed by the compressor 11 to become a high-temperature / high-pressure state refrigerant, thereby condensing heat. It will be sent to the exchanger 12.

  Further, the heat pump unit 1 is provided with means for defrosting operation of the evaporating heat exchanger 14. That is, a bypass 18 is provided for supplying the refrigerant discharged from the compressor 11 and entering the condensation heat exchanger 12 directly to the evaporation heat exchanger 14 by bypassing the condensation heat exchanger 12 and the expansion valve 13. It is installed. A defrost valve 19 is provided in the bypass 18 as an opening / closing control valve for defrosting operation, and this defrosting electromagnetic valve 19 is kept closed during normal operation, while open conversion control is performed during defrosting operation described later. Thus, the refrigerant discharged from the compressor 11 can be directly supplied to the evaporating heat exchanger 14. Further, the outside air temperature is detected by the outside air temperature sensor 20 and is output to the control device 3. The bypass channel 18 and the defrosting electromagnetic valve 19 constitute a defrosting channel.

  On the other hand, in the hot water supply circuit 2, when the water in the hot water storage tank 21 is pumped to the condensation heat exchanger 12 by the operation of the water supply pump 23, before the heat exchange heating is performed by the incoming water temperature sensor 24 in front of the inlet of the condensation heat exchanger 12. So that the boiling temperature is detected by the tapping temperature sensor 25 on the outlet side of the condensing heat exchanger 12 when the hot water is heated by heat exchange by passing through the condensing heat exchanger 12 and discharged. It has become. These detected incoming water temperature and detected boiling temperature are output to the control device 3. The hot water heated by the condensation heat exchanger 12 is returned to the top side of the hot water storage tank 21 and stored, and is used for subsequent hot water supply. If the amount of hot water in the hot water storage tank 21 is reduced by hot water supply, water is supplied accordingly.

  The control device 3 includes a control unit and an inverter device that constitutes a heat generating element, and is installed so as to be able to exchange heat with the refrigerant pipe 15 a extending from the evaporating heat exchanger 14 to the compressor 11. Specifically, as illustrated in FIG. 2, one surface of the power module 31 including the inverter device or the like is installed in close contact with one surface of the control board 32 while being in contact with the other surface of the power module 31. Is attached with a heat sink 33 provided with a plurality of radiating fins 331, 331,. These radiating fins 331, 331,... Constitute a heat sink 33, and a heat sink temperature sensor 17 for detecting the temperature of the heat sink 33 (hereinafter referred to as "heat sink temperature") is installed at a predetermined position of the heat sink 33. Yes. Then, the refrigerant pipe 15 a is piped in contact with the heat sink 33 (radiation fin 331), thereby heat conduction between the refrigerant flowing in the refrigerant pipe 15 a and the power module 31 of the control device 3. The heat exchange is possible. Therefore, the heat generated by the power module 31 is absorbed and the refrigerant is heated, while the power module 31 is cooled by taking heat away from the refrigerant. In this case, since the heat conductivity is good, the refrigerant temperature in the refrigerant pipe 15a (= evaporation heat exchanger outlet temperature) and the heat sink temperature are equal to each other. It is possible to output either the evaporative heat exchanger outlet temperature sensor installed or the heat sink temperature sensor 17 installed on the heat sink 33. In the present embodiment, an example is shown in which the installation of the evaporative heat exchanger outlet temperature sensor is omitted and the heat sink temperature sensor 17 plays the role of the evaporative heat exchanger outlet temperature sensor.

  In the heat pump type hot water supply apparatus described above, normal operation control for controlling the water on the hot water supply circuit 2 side to be heated by the condensing heat exchanger 12 with the target boiling temperature as the target temperature, and evaporation when the defrost operation start condition is satisfied. The control device 3 executes defrosting operation control for controlling the heat exchanger 14 to melt frost.

  The normal operation control is based on, for example, the detected outside air temperature by the outside air temperature sensor 20 at the time of the current operation, the detected incoming water temperature by the incoming water temperature sensor 24, the detected discharge temperature by the discharge temperature sensor 16, the target boiling temperature, etc. The rotational speed of the compressor 11 is changed and controlled so that the boiling temperature detected by the tapping temperature sensor 25 becomes the target boiling temperature, the opening degree of the expansion valve 13 is changed or controlled, or the circulation flow rate of the feed water pump 23 is changed. It is designed to change or control.

  The defrosting operation control monitors whether or not the defrosting operation start condition is satisfied. When the defrosting operation start condition is satisfied, the defrosting operation control is started, and when the return condition to the normal operation is satisfied, Return control for returning to operation control is executed. As a defrosting operation start condition, for example, the temperature of the evaporative heat exchanger 14 (for example, can be grasped by the heat sink temperature detected by the heat sink temperature sensor 17) is lowered to a predetermined set temperature that requires defrosting due to frost formation. Can be set.

  In the defrosting operation control, the defrosting electromagnetic valve 19 is subjected to open conversion control, and the compressed high-temperature refrigerant discharged from the compressor 11 is directly introduced into the evaporating heat exchanger 14 through the bypass path 18. Try to melt the frost. At this time, the higher the temperature of the high-temperature refrigerant discharged from the compressor 11, the higher the defrosting efficiency. However, if the temperature is too high, the controller 3 may be adversely affected. For this reason, during the defrosting operation control, as shown in FIG. 3, the compressor 11 is configured so that the heat sink temperature detected by the heat sink temperature sensor (first temperature sensor) 17 does not become higher than a predetermined allowable upper limit temperature Ta. Temperature management control for controlling the operation is also performed. That is, by controlling the compression operation amount of the compressor 11, the discharge temperature of the refrigerant supplied as a heat source for defrosting to the evaporative heat exchanger 14 is adjusted, and the evaporative heat exchanger outlet temperature (= heat sink temperature) Therefore, the allowable upper limit temperature Ta is not exceeded. The allowable upper limit temperature Ta is lower than the upper limit temperature at which the inverter device or the like of the control device 3 is not damaged, and the heat generation from the power module 31 is absorbed through the heat sink 33 to maintain the cooling action on the power module 31. An upper limit temperature within the temperature range to be obtained, for example, 90 ° C. can be set. As described above, the cooling function for the power module 31 can be reliably ensured, and at the same time, the possibility of damage due to overheating of the power module 31 can be surely avoided.

  In the case of the above embodiment, when the normal operation control is being executed, the control device 3 (particularly the inverter) is obtained by heat exchange with the refrigerant that is vaporized by the evaporative heat exchanger 14 and then sent to the compressor 11 through the refrigerant pipe 15a. Apparatus) can be sufficiently cooled, and the refrigerant before being introduced into the compressor 11 can be further heated by causing the refrigerant to absorb heat generated by the control device 3. Furthermore, even when the defrosting operation control is being executed, heat exchange with the refrigerant that is directly introduced from the compressor 11 into the evaporative heat exchanger 14 and defrosted and then sent to the compressor 11 is performed. Thus, the control device 3 (particularly the inverter device) can be cooled. Thereby, the cooling function to the control apparatus 3 at the time of a defrost operation is securable only by heat exchange with the refrigerant | coolant in the refrigerant | coolant piping 15a, without installing means, such as a cooling fan. For this reason, it becomes possible to achieve downsizing.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Other various embodiment is included. That is, in the said embodiment, although the example (refer FIG. 2) which arrange | positioned the refrigerant | coolant piping 15a between the radiation fins 331 and 331 which comprise the heat sink 33 was shown, not only this but a heat radiation part other than a radiation fin is provided. The refrigerant pipe 15a can be piped in contact with the heat sink, and a hole portion (refrigerant flow path) corresponding to the refrigerant pipe 15a is formed through the plate-like portion constituting the heat sink. It can also be made to pass. In such a case as well, the control device is disposed so as to be able to exchange heat with the refrigerant in the refrigerant flow path, and the control device is disposed in contact with the refrigerant pipe that is the refrigerant flow path.

  In the above embodiment, the evaporative heat exchanger outlet temperature sensor is omitted, and the heat sink temperature sensor (first temperature sensor) 17 plays a role thereof. It is possible to omit the evaporative heat exchanger outlet temperature sensor (second temperature sensor) and to determine the heat sink temperature from the evaporative heat exchanger outlet temperature detected by the second temperature sensor. In other words, the temperature control executed in conjunction with the defrosting operation control controls the operation of the compressor so that the evaporative heat exchanger outlet temperature detected by the evaporative heat exchanger outlet temperature sensor does not exceed the allowable upper limit temperature Ta. It is.

1 Heat pump unit (refrigeration circuit)
2 Hot water supply circuit 3 Control device 31 Power module (heating element)
33 Heat sink 11 Compressor 12 Condensation heat exchanger 13 Expansion valve 14 Evaporation heat exchanger 15 Refrigerant piping (refrigerant flow path)
15a Refrigerant piping (refrigerant flow path) from the evaporation heat exchanger to the compressor
17 Heat sink temperature sensor (first temperature sensor)
18 Bypass path (flow path for defrosting)
19 Defrosting solenoid valve (flow path for defrosting)

Claims (4)

A compressor, a condensing heat exchanger, an expansion valve, and a refrigerating circuit in which the evaporating heat exchanger is sequentially communicated with the refrigerant flow path; and a control device for controlling the operation of the refrigerating circuit, the condensing heat exchanger In the heat pump type hot water supply apparatus configured to be capable of heat exchange heating with hot water for hot water supply using the refrigerant discharged from the compressor,
The refrigeration circuit defrosts the evaporative heat exchanger by directly supplying the refrigerant discharged from the compressor to the inlet of the evaporative heat exchanger, bypassing the condensation heat exchanger and the expansion valve. A flow path for defrosting that can be switched to perform
The control device is provided with a heating element that generates heat upon operation thereof,
The heat generating element is disposed so as to be able to exchange heat with the refrigerant in the refrigerant flow path with respect to the refrigerant flow path from the evaporation heat exchanger to the compressor.
A heat pump type hot water supply apparatus characterized by that. The heat pump type hot water supply apparatus according to claim 1,
The heat generating element includes a heat sink, and the heat pump is provided so as to be able to exchange heat by being disposed in contact with a refrigerant flow path from the evaporative heat exchanger to the compressor. . The heat pump type hot water supply device according to claim 2,
A first temperature sensor for detecting the temperature of the heat sink;
The said control apparatus is a heat pump type hot water supply apparatus comprised so that the action | operation of the said compressor may be controlled so that the temperature of the heat sink detected by the 1st temperature sensor may become below predetermined temperature. The heat pump type hot water supply apparatus according to claim 1 or 2,
A second temperature sensor for detecting the temperature of the refrigerant derived from the outlet of the evaporative heat exchanger;
The said control apparatus is a heat pump type hot water supply apparatus comprised so that the action | operation of the said compressor may be controlled so that the refrigerant | coolant temperature detected by the said 2nd temperature sensor may be below predetermined temperature.

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