Heat pump device, air conditioner, heat pump water heater, refrigerator, and freezer

Abstract

A heat pump device (1) comprises a compressor (30) that compresses a refrigerant, an outdoor heat exchanger (33) that transfers heat of the refrigerant to air, a fan (5) that sends air by rotating blades of a rotor, and a controller (20) that applies voltage to the compressor (30) and the fan (5). When heating the refrigerant within the compressor (30) while the compressor (30) is in operation standby, in the case where refrigerant evaporation information, which corresponds to an electricity amount necessary for evaporating the refrigerant, is equal to or more than a reference value, the controller (20) determines to rotate the fan (5) and applies voltage to the fan (5) to cause the fan (5) to cool the controller (20).

Description

Heat pump devices, air conditioners, heat pump water heaters, refrigerators, and freezers

[0001] The present disclosure relates to a heat pump device, an air conditioner, a heat pump water heater, a refrigerator, and a freezer that vaporize a refrigerant in a compressor during standby.

[0002] There are techniques for preventing refrigerant from accumulating inside the compressor during standby of a heat pump device used in an air conditioner, etc. One such technique involves heating the compressor by passing current through the motor windings without driving the motor inside the compressor, thereby vaporizing the refrigerant inside the compressor and discharging it from the compressor.

[0003] For example, the heat pump device described in Patent Document 1, when heating the refrigerant inside the compressor while the compressor is in standby mode, energizes the motor using direct current when the amount of heat to be applied to the refrigerant is large, and energizes the motor using high frequency when the amount of heat to be applied is small. In this way, the heat pump device described in Patent Document 1 efficiently heats the refrigerant according to the required amount of heat.

[0004] Patent No. 5937619

[0005] However, in the technology of Patent Document 1, when a refrigerant that is difficult to vaporize is used, the increase in the amount of electricity used to heat the refrigerant causes the temperature of the controller that controls the heat pump device to rise, reducing the reliability of the controller.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a heat pump device that can prevent refrigerant from stagnating inside the compressor while preventing a decrease in the reliability of the controller, even when a refrigerant that is difficult to vaporize is used.

[0007] To solve the above-mentioned problems and achieve the object, the heat pump device of the present disclosure includes a compressor that compresses a refrigerant, a heat exchanger that transfers heat of the refrigerant to air, a fan that blows air by rotating blades of a rotor, and a controller that applies voltage to the compressor and the fan. When refrigerant evaporation information, which is information corresponding to the amount of power required to vaporize the refrigerant, is equal to or greater than a reference value when heating the refrigerant inside the compressor while the compressor is in standby mode, the controller determines to rotate the fan and applies voltage to the fan, thereby cooling the controller with the fan.

[0008] The heat pump device according to the present disclosure has the advantage of being able to prevent refrigerant from stagnating inside the compressor while preventing a decrease in the reliability of the controller, even when a refrigerant that is difficult to vaporize is used.

[0009] FIG. 1 is a diagram showing a configuration example of a heat pump device according to a first embodiment; FIG. 2 is a flowchart showing a processing procedure for a refrigerant heating operation process in a heat pump device according to a first embodiment; FIG. 3 is a diagram showing a configuration example of a processing circuit provided in a controller according to a first embodiment when the processing circuit is realized by a processor and a memory; FIG. 4 is a diagram showing an example of a processing circuit provided in a controller according to a first embodiment when the processing circuit is configured by dedicated hardware;

[0010] A heat pump device, an air conditioner, a heat pump water heater, a refrigerator, and a freezer according to embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0011] 1 is a diagram showing a configuration example of a heat pump device according to a first embodiment. The heat pump device 1 according to the first embodiment is connected to an AC power supply 4. The heat pump device 1 is applied to, for example, an air conditioner, a heat pump water heater, a refrigerator, or a freezer.

[0012] The following describes a case where the heat pump device 1 is applied to an air conditioner. The heat pump device 1 includes an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 includes a controller 20, a compressor 30, a four-way valve 36, an outdoor heat exchanger 33 that transfers heat of the refrigerant to air, and refrigerant piping 6.

[0013] The outdoor unit 2 also has a fan 5 that sends air to the controller 20 and the outdoor heat exchanger 33. The fan 5 has blades (rotating blades) 50 that serve as a blowing mechanism, and a fan motor 51 that drives the blades 50.

[0014] The outdoor unit 2 also has a cooler 40 that cools the controller 20, a temperature detector 41 that detects the temperature of the cooler 40, and a temperature detector 42 that detects the outside air temperature of the environment in which the outdoor unit 2 is installed. The outside air temperature in the first embodiment is the temperature outside the refrigerant circuit through which the refrigerant circulates. The cooler 40 is, for example, a heat sink arranged in contact with the controller 20.

[0015] The indoor unit 3 has an expansion device 34, an indoor heat exchanger 35 that transfers heat of the refrigerant to air, and refrigerant piping 6. The expansion device 34 controls the flow rate of the refrigerant by expanding and decompressing the refrigerant. Note that the expansion device 34 may be included in the outdoor unit 2 instead of the indoor unit 3.

[0016] The compressor 30 includes a compressor motor 32 and a compression element 31. That is, the compressor 30 includes the compression element 31, which is a compression mechanism that compresses the refrigerant, and the compressor motor 32 that operates the compression element 31.

[0017] The controller 20 includes a power converter 25 and a control unit (not shown). In the heat pump unit 1, a refrigerant circuit is configured in which a refrigerant circulates, with the compressor 30, four-way valve 36, outdoor heat exchanger 33, expansion device 34, indoor heat exchanger 35, four-way valve 36, and compressor 30 connected in this order by refrigerant piping 6. Thus, the refrigerant circuit in the heat pump unit 1 includes the compressor 30, four-way valve 36, outdoor heat exchanger 33, expansion device 34, indoor heat exchanger 35, and refrigerant piping 6. The four-way valve 36 is a valve that switches the path of the refrigerant circuit. Note that the configuration of the refrigerant circuit shown in FIG. 1 is an example, and the configuration of the refrigerant circuit of the heat pump unit 1 does not necessarily have to be the same as the configuration of the refrigerant circuit shown in FIG. 1.

[0018] The AC power supply 4 is connected to the controller 20, and supplies power to the controller 20. The controller 20 applies a voltage to the compressor 30 and the fan 5 to control them. Specifically, the controller 20 controls the compressor motor 32 of the compressor 30 and the fan motor 51 of the fan 5. The controller 20 also controls the refrigerant circuit. A control unit of the controller 20 outputs a drive signal to the power conversion device 25, causing the power conversion device 25 to drive the compressor motor 32 and the fan motor 51.

[0019] The power conversion device 25 has a converter (not shown) that converts AC power into DC power, a compressor drive inverter (not shown) that drives the compressor motor 32, and a fan motor drive inverter (not shown) that drives the fan motor 51. The converter of the power conversion device 25 converts AC power supplied from the AC power source 4 into DC power and supplies it to the compressor drive inverter and the fan motor drive inverter.

[0020] The compressor drive inverter of the power conversion device 25 outputs the three-phase AC voltage to the compressor motor 32 to rotate and drive the compressor motor 32. In addition, the fan motor drive inverter of the power conversion device 25 outputs the three-phase AC voltage to the fan motor 51 to rotate and drive the fan motor 51.

[0021] The compressor motor 32 is connected to the compression element 31. The compressor motor 32 is a three-phase motor having windings for three phases: U phase, V phase, and W phase. The compressor 30 compresses the refrigerant by the compressor motor 32 and the compression element 31.

[0022] A compressor drive inverter is electrically connected to the compressor motor 32. The compressor drive inverter is connected to a converter, and uses a DC voltage (bus voltage) supplied from the converter as a power source to apply a U-phase voltage, a V-phase voltage, and a W-phase voltage to the U-phase, V-phase, and W-phase windings of the compressor motor 32, respectively.

[0023] A fan motor drive inverter is electrically connected to the fan motor 51. The fan motor drive inverter is connected to a converter, and uses a DC voltage (bus voltage) supplied from the converter as a power source to apply a U-phase voltage, a V-phase voltage, and a W-phase voltage to the U-phase, V-phase, and W-phase windings of the fan motor 51, respectively.

[0024] A control unit is electrically connected to the compressor drive inverter and the fan motor drive inverter, and outputs a drive signal to the compressor drive inverter for driving the compressor drive inverter and a drive signal to the fan motor drive inverter for driving the fan motor drive inverter.

[0025] During standby (stopped operation), the heat pump device 1 vaporizes the refrigerant by heating the compressor 30 to prevent refrigerant stagnation, which is a state in which the refrigerant accumulates (stagnates) inside the compressor 30. That is, the heat pump device 1 heats the compressor 30 so that the refrigerant stagnation does not occur during standby.

[0026] The compressor motor 32 has motor windings (not shown), and the power conversion device 25 heats the compressor 30 by energizing (constrained energization) the motor windings. If the compressor 30 is not heated while the compressor 30 is in standby (stopped), a drop in the temperature within the compressor 30 can cause refrigerant oil and liquid refrigerant to accumulate within the compressor 30, resulting in a refrigerant stagnation state. When the compressor 30 is started after this refrigerant stagnation state occurs, the refrigerant is more easily supplied to the sliding parts (rolling piston parts) within the compressor 30, while the refrigerant oil is less easily supplied to the sliding parts. This can result in poor lubrication of the sliding parts and potentially damage to the compressor 30. Therefore, the heat pump device 1 heats the compressor 30 during standby to vaporize the refrigerant and prevent the refrigerant stagnation state.

[0027] In the heat pump device 1, if the controller 20 becomes too hot, the reliability of the controller 20 decreases. Therefore, the heat pump device 1 cools the controller 20 by rotating the fan 5 (rotating the rotating shaft and blades 50 of the fan motor 51) before the controller 20 becomes too hot, thereby lowering the temperature of the controller 20.

[0028] The controller 20 in the first embodiment determines whether to rotate the fan 5 (whether to apply a voltage to the fan 5) based on information corresponding to the amount of power required to vaporize the refrigerant. The amount of power required to vaporize the refrigerant is the amount of power required to vaporize the refrigerant without causing the refrigerant to become stagnant. In the following description, information corresponding to the amount of power required to vaporize the refrigerant may be referred to as refrigerant vaporization information. The refrigerant vaporization information may be, for example, the amount of power required to heat the compressor 30 (hereinafter, sometimes referred to as heating power amount).

[0029] When the controller 20 outputs or converts electric power, a loss occurs in the controller 20, and this loss appears as heat. This heat generation by the controller 20 causes the temperature of the controller 20 to rise. In this case, the temperature of the controller 20 increases in proportion to the amount of electric power that the controller 20 provides to the compressor motor 32. For this reason, in the first embodiment, the controller 20 determines whether to rotate the fan 5 based on refrigerant vaporization information such as the amount of heating electric power.

[0030] When the refrigerant vaporization information is the amount of heating power, the refrigerant vaporization information is the amount of current supplied to the motor windings, i.e., the amount of power that the controller 20 outputs to the motor windings to vaporize the refrigerant so that the refrigerant does not become stagnant.

[0031] The amount of power required to vaporize the refrigerant (amount of current flowing through the motor windings) varies depending on the rate of rise in the outdoor air temperature in the ambient environment of the outdoor unit 2, even for the same air conditioner. In other words, the heating capacity required to vaporize the refrigerant (amount of current flowing through the motor windings) increases in proportion to the rate of rise in the outdoor air temperature. For this reason, the refrigerant vaporization information may be the rate of rise in the outdoor air temperature in the environment in which the outdoor unit 2 is located (the ambient environment of the outdoor unit 2). The rate of rise in the outdoor air temperature is the rate at which the outdoor air temperature rises per unit time. This outdoor air temperature is detected by the temperature detection unit 42.

[0032] The temperature of the refrigerant circuit easily follows the outside air temperature, but the temperature of the compressor 30 does not easily follow the outside air temperature. Therefore, when the outside air temperature changes suddenly, the temperature of the refrigerant circuit approaches the outside air temperature in a short time, but the temperature of the compressor 30 approaches the outside air temperature only slowly. For example, when the outside air temperature rises suddenly, the temperature of the refrigerant circuit approaches the outside air temperature in a short time, but it takes a long time for the temperature of the compressor 30 to approach the outside air temperature. In this case, the temperature of the compressor 30 becomes lower than the temperature of the refrigerant circuit. Because refrigerant collects in low-temperature areas, when the temperature of the compressor 30 is lower than the temperature of the refrigerant circuit, refrigerant collects in the compressor 30, making it more likely that refrigerant stagnation will occur. In other words, the faster the outside air temperature rises, the more likely that refrigerant stagnation will occur.

[0033] In this way, the rate of rise of the outside air temperature corresponds to the likelihood of the refrigerant stagnation state occurring. Furthermore, the magnitude of the amount of heating power corresponds to the likelihood of the refrigerant stagnation state occurring. In other words, the faster the rate of rise of the outside air temperature, the more likely the refrigerant stagnation state occurs, and the more likely the refrigerant stagnation state occurs, the greater the amount of heating power. Therefore, the refrigerant vaporization information for vaporizing the refrigerant to prevent it from becoming refrigerant stagnation may be the rate of rise of the outside air temperature. Note that if the refrigerant vaporization information is the amount of power required to vaporize the refrigerant, the heat pump device 1 does not need to be equipped with a temperature detection unit 42.

[0034] The temperature detection unit 42 detects the outside air temperature at specific intervals (for example, every minute). The controller 20 calculates the rate of rise of the outside air temperature based on the detected change in the outside air temperature. The controller 20 also calculates the amount of heating power based on the rate of rise of the outside air temperature. The controller 20 calculates a larger amount of heating power as the rate of rise of the outside air temperature increases.

[0035] The controller 20 calculates the amount of heating power using, for example, a formula that indicates the correspondence relationship between the rate of rise in the outside air temperature and the amount of heating power. Note that the controller 20 may also calculate the amount of heating power using a data table that indicates the correspondence relationship between the rate of rise in the outside air temperature and the amount of heating power.

[0036] The controller 20 determines to rotate the fan 5 when the amount of heating power is equal to or greater than a first reference value. In this case, the controller 20 may calculate the rotation speed of the fan 5 based on the amount of heating power and apply a voltage corresponding to the calculation result to the fan 5. In other words, the controller 20 may rotate the fan 5 at a rotation speed corresponding to the amount of heating power.

[0037] Note that the controller 20 may use, as the amount of heating power, an inverter output voltage value or an inverter output current value that can estimate the thermal load of the controller 20. In this case, the controller 20 determines whether to rotate the fan 5 based on the inverter output voltage value or the inverter output current value that can estimate the thermal load of the controller 20.

[0038] The inverter output voltage value is a voltage value output from the compressor drive inverter to the compressor 30, and the inverter output current value is a current value output from the compressor drive inverter to the compressor 30. The inverter output voltage value and the inverter output current value may be any of a detected value, a calculated value, and an output command value. In addition, the controller 20 may add the amount of power required to rotate the fan 5 to the amount of heating power.

[0039] Furthermore, the controller 20 may determine to rotate the fan 5 when the rate of rise of the outside air temperature is equal to or greater than a second reference value. In this case, the controller 20 may calculate the rotation speed of the fan 5 based on the magnitude of the rate of rise of the outside air temperature, and apply a voltage to the fan 5 based on the calculation result. In other words, the controller 20 may rotate the fan 5 at a rotation speed corresponding to the magnitude of the rate of rise of the outside air temperature.

[0040] The refrigerant vaporization information may be the temperature of the cooler 40 (cooler temperature) detected by the temperature detection unit 41. Because the cooler 40 is in contact with the controller 20, the temperature of the cooler 40 corresponds to the temperature of the controller 20. When the refrigerant vaporization information is the temperature of the cooler 40, the controller 20 can estimate the absolute temperature of the controller 20 based on the temperature of the cooler 40.

[0041] When the refrigerant evaporation information is the temperature of the cooler 40, the controller 20 determines to rotate the fan 5 when the temperature of the cooler 40 is equal to or higher than a third reference value. In this case, the controller 20 may calculate the rotation speed of the fan 5 based on the size of the cooler 40 and apply a voltage to the fan 5 based on the calculation result. In other words, the controller 20 may rotate the fan 5 at a rotation speed corresponding to the magnitude of the cooler temperature.

[0042] Since the controller 20 has multiple heat generation sources, the temperature of each component of the controller 20 may be measured, or the temperature of the cooler 40 may be measured, which corresponds to the temperature of the controller 20, as described above. The temperature of the cooler 40 increases in proportion to the heat generation temperature of the controller 20, so by cooling multiple heat generation sources together with a single cooler 40, the heat pump device 1 can be easily manufactured and manufacturing costs can be reduced.

[0043] The rotation speed of fan 5 required to cool controller 20 varies depending on the outdoor air temperature, which is the ambient environment of outdoor unit 2, and the heat generation state of controller 20, even for the same air conditioner. The heat generation state of controller 20 is the temperature of controller 20. The temperature of controller 20 corresponds to the temperature of cooler 40. Therefore, controller 20 may calculate the rotation speed of fan 5 based on the temperatures detected by temperature detection unit 41 and temperature detection unit 42, and calculate the drive voltage value of fan 5 corresponding to the rotation speed of fan 5. Note that controller 20 may calculate the rotation speed of fan 5 based on the temperature detected by temperature detection unit 41, without taking into account the temperature detected by temperature detection unit 42.

[0044] The refrigerant vaporization information may also be the absolute value of the outside air temperature detected by the temperature detection unit 42. When the refrigerant vaporization information is the absolute value of the outside air temperature, the controller 20 determines to rotate the fan 5 when the absolute value of the outside air temperature is equal to or greater than a fourth reference value. In this case, the controller 20 may calculate the rotation speed of the fan 5 based on the magnitude of the absolute value of the outside air temperature and apply a voltage to the fan 5 based on the calculation result. In other words, the controller 20 may rotate the fan 5 at a rotation speed corresponding to the magnitude of the absolute value of the outside air temperature.

[0045] In the first embodiment, it is sufficient to prevent failure of the controller 20 due to overheating, so the rotation speed required under strict estimated conditions (such as a state in which the amount of output power to the compressor 30 is large and the outside air temperature is high) may be used. Therefore, the controller 20 may rotate the fan 5 at a specific rotation speed that can reduce the temperature of the controller 20 to a specific value or less even under strict conditions.

[0046] There are a normal operation mode and a heating operation mode as operation modes executed by the heat pump device 1. In the normal operation mode, the controller 20 generates a PWM (Pulse Width Modulation) signal (drive signal) for driving the compressor motor 32 to rotate, and outputs the PWM signal to the compressor motor 32.

[0047] Furthermore, in the heating operation mode, unlike the normal operation mode, the controller 20 heats the compressor motor 32 by energizing the compressor motor 32 during standby so as not to drive the compressor motor 32 in rotation, and heats, vaporizes, and discharges the liquid refrigerant accumulated inside the compressor 30. That is, in the heating operation mode, the power conversion device 25 passes current through the compressor motor 32, thereby utilizing the heat generated by the compressor motor 32 to heat the refrigerant accumulated inside the compressor 30. In this way, in the heating operation mode, heating is performed by energizing the compressor motor 32 so as not to drive the compressor motor 32 in rotation.

[0048] Here, the cooling operation, which is the operation of the air conditioner, will be described. Prior to the cooling operation, the four-way valve 36 switches the flow path in advance so that the refrigerant discharged from the compressor 30 flows toward the outdoor heat exchanger 33, and the refrigerant flowing out of the indoor heat exchanger 35 flows toward the compressor 30. Note that although a detailed description of the heating operation will be omitted here, the cooling operation and the heating operation are switched by switching the flow path in the four-way valve 36.

[0049] In the heat pump device 1, the power conversion device 25 drives the compressor motor 32 to rotate, causing the compression element 31 connected to the compressor motor 32 to compress the refrigerant, and the compressor 30 to discharge a high-temperature, high-pressure refrigerant. The high-temperature, high-pressure refrigerant discharged from the compressor 30 flows into the outdoor heat exchanger 33 via the four-way valve 36, where it exchanges heat with outside air supplied (blowed) by the fan 5, thereby releasing heat.

[0050] The refrigerant flowing out of the outdoor heat exchanger 33 is expanded and decompressed by the expansion device 34, becoming a low-temperature, low-pressure, two-phase gas-liquid refrigerant, which flows into the indoor heat exchanger 35, exchanges heat with the air in the space to be air-conditioned, evaporates, and becomes a low-temperature, low-pressure gas refrigerant, which flows out of the indoor heat exchanger 35. The gas refrigerant flowing out of the indoor heat exchanger 35 is drawn into the compressor 30 via the four-way valve 36 and compressed again. The heat pump unit 1 performs cooling operation by repeating the above operations.

[0051] Next, a description will be given of an example of a refrigerant used by the heat pump device 1. The heat pump device 1 uses, for example, a fluorine-based refrigerant or a hydrocarbon-based refrigerant having a low global warming potential (GWP).

[0052] The heat pump device 1 uses, for example, a low GWP refrigerant whose polytropic index is smaller than that of an HFC (hydrofluorocarbon) refrigerant. An HFC refrigerant is a chlorofluorocarbon (CFC) alternative. An HFC is a compound in which at least a portion of the hydrogen contained in an HC (hydrocarbon, a hydrocarbon compound) is replaced with fluorine. An example of an HFC refrigerant is R (Refrigerant) 32.

[0053] The heat pump device 1 uses, for example, an HC refrigerant, which is a non-fluorocarbon gas. An example of the HC refrigerant is R290, which is a single refrigerant.

[0054] The heat pump device 1 is not limited to using R290, and may use R32 as a single refrigerant. The heat pump device 1 may also use R1234yf as a single refrigerant or R1234ze as a single refrigerant.

[0055] Furthermore, the heat pump device 1 may use a mixed refrigerant of any two or more of R1234yf, R1234ze, R32, and R290, or a mixed refrigerant of at least one of these with another refrigerant.

[0056] The heat pump device 1 may also use a mixed refrigerant containing an HFO (hydrofluoroolefin) refrigerant. HFO refrigerants are non-chlorofluorocarbon gases. Examples of HFO refrigerants include R1234yf, R1234ze, R1123, and R1123(E).

[0057] The heat pump device 1 may use, for example, a mixed refrigerant of an HFC refrigerant and an HFO refrigerant, such as R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, or R459A as the mixed refrigerant of an HFC refrigerant and an HFO refrigerant.

[0058] The heat pump device 1 can vaporize a refrigerant that has a polytropic index smaller than that of an HFC refrigerant and is difficult to vaporize sufficiently by sufficiently heating the compressor 30. In this case, even if the compressor 30 is sufficiently heated, the heat pump device 1 can maintain the controller 20 below a specific temperature by rotating the fan 5, thereby maintaining the reliability of the controller 20. This prevents liquid refrigerant from accumulating inside the compressor 30, suppressing damage to the compressor sliding parts, while maintaining the reliability of the controller 20.

[0059] Here, the polytropic exponent will be explained. The relationship between the pressure and volume of a gas can be approximately expressed by the following equation (1).

[0060] pV n =Const...(1)

[0061] Here, p is the pressure of the gas, V is the volume of the gas, and n is the polytropic index. For example, when the state of a gas changes from state C1 to state C2, the characteristics of this change can be expressed by the value of the polytropic index. For example, a refrigerant (gas) changes as follows for each value of the polytropic index: n=0: isobaric change n=1: isothermal change n=γ: adiabatic change n=∞: isovolumetric change

[0062] As can be seen from these relationships, when the polytropic index is relatively small, pressure does not change easily even when the volume is compressed. Furthermore, when pressure does not change easily, temperature generally does not increase easily. That is, with an HC refrigerant, which has a relatively small polytropic index, the refrigerant temperature does not increase easily even when compressed by the compressor 30, making it difficult to eliminate refrigerant stagnation. In the first embodiment, the controller 20 is maintained below a specific temperature by rotating the fan 5 while sufficiently heating the compressor 30 to vaporize the HC refrigerant. This prevents HC refrigerant from accumulating inside the compressor 30, suppressing damage to the compressor sliding parts and maintaining the reliability of the controller 20.

[0063] Next, the refrigerant heating operation process in the heat pump device 1 according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the procedure of the refrigerant heating operation process in the heat pump device according to the first embodiment.

[0064] During standby, the controller 20 determines whether heating of the compressor 30 is necessary (step S10). The controller 20 determines whether heating of the compressor 30 is necessary based on, for example, the rate of increase in the outside air temperature. In this case, the controller 20 determines that heating of the compressor 30 is necessary when the rate of increase in the outside air temperature is equal to or greater than a specific value.

[0065] In addition, if the heat pump device 1 is equipped with a detection device that detects the amount of refrigerant stagnation inside the compressor 30, the controller 20 may determine whether or not heating to the compressor 30 is necessary based on the amount of refrigerant stagnation detected by the detection device.

[0066] When the controller 20 determines that heating of the compressor 30 is not necessary (No in step S10), the controller 20 continues to determine whether heating of the compressor 30 is necessary (step S10). That is, the controller 20 repeatedly executes the process of determining whether heating is necessary until it determines that heating of the compressor 30 is necessary.

[0067] When the controller 20 determines that the compressor 30 needs to be heated (Yes in step S10), the controller 20 acquires refrigerant vaporization information (step S20). When the controller 20 determines that the refrigerant is stagnating inside the compressor 30 or when it is estimated that the refrigerant is stagnating inside the compressor 30, the controller 20 determines that the compressor 30 needs to be heated.

[0068] The refrigerant vaporization information acquired by the controller 20 is the amount of heating power required to vaporize the refrigerant, the rate of rise of the outside air temperature, or the temperature of the cooler 40. The controller 20 determines whether the refrigerant vaporization information is equal to or greater than a reference value (step S30). If the refrigerant vaporization information is equal to or greater than the reference value, the controller 20 determines to rotate the fan 5.

[0069] For example, when the refrigerant vaporization information is the amount of heating power, the controller 20 determines to rotate the fan 5 if the amount of heating power is equal to or greater than a first reference value.

[0070] Furthermore, when the refrigerant evaporation information is the rate of rise of the outside air temperature, the controller 20 determines to rotate the fan 5 if the rate of rise of the outside air temperature is equal to or greater than a second reference value.

[0071] Furthermore, when the refrigerant evaporation information is the temperature of the cooler 40, the controller 20 determines to rotate the fan 5 if the temperature of the cooler 40 detected by the temperature detection unit 41 is equal to or higher than a third reference value.

[0072] When the controller 20 determines that the refrigerant evaporation information is equal to or greater than the reference value (Yes in step S30), the controller 20 cools the refrigerant ...

[0073] When the controller 20 determines that the refrigerant evaporation information is less than the reference value (No in step S30), the controller 20 stops the fan 5 (step S50). Note that the reference value used to determine whether to rotate the fan 5 and the reference value (specific value) used to determine whether to stop the fan 5 may be different values.

[0074] Here, a hardware configuration of the controller 20 according to the first embodiment will be described. The controller 20 is realized by a processing circuit. The processing circuit may be a processor and memory that executes a program stored in a memory, or may be dedicated hardware.

[0075] 3 is a diagram illustrating an example of the configuration of a processing circuit when the processing circuit included in the controller according to the first embodiment is realized by a processor and a memory. The processing circuit 90 illustrated in FIG. 3 includes a processor 91 and a memory 92.

[0076] When the processing circuit 90 is composed of a processor 91 and a memory 92, each function of the processing circuit 90 is realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a data processing program and stored in the memory 92. In the processing circuit 90, each function is realized by the processor 91 reading and executing the data processing program stored in the memory 92. That is, the processing circuit 90 includes the memory 92 for storing a data processing program that results in the processing of the controller 20 being executed. This data processing program can also be said to be a program that causes the controller 20 to execute each function realized by the processing circuit 90. This data processing program may be provided by a storage medium on which the data processing program is stored, or by other means such as a communication medium.

[0077] Here, the processor 91 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor), etc. The memory 92 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disc).

[0078] FIG. 4 is a diagram illustrating an example of a processing circuit provided in the controller according to the first embodiment, configured with dedicated hardware. The processing circuit 93 illustrated in FIG. 4 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The processing circuit 93 may be partially implemented with dedicated hardware and partially implemented with software or firmware. In this way, the processing circuit 93 can realize each of the above-described functions by dedicated hardware, software, firmware, or a combination thereof.

[0079] As described above, the heat pump apparatus 1 of the first embodiment rotates the fan 5 when the refrigerant evaporation information is equal to or greater than the reference value during preheating control before the compressor is driven. This makes it possible to suppress heat generation in the controller 20 that accompanies an increase in the amount of current flow, without increasing the size of the cooler 40 or adding a new cooler. This allows the heat pump apparatus 1 to prevent refrigerant from accumulating inside the compressor 30 without reducing the reliability of the controller 20. Therefore, the heat pump apparatus 1 can prevent damage to the sliding parts of the compressor 30 that occurs when the liquid refrigerant cannot be sufficiently evaporated after the compressor 30 is started, without reducing the reliability of the controller 20.

[0080] Furthermore, the heat pump unit 1 of the first embodiment rotates the fan 5 when the temperature of the cooler 40, which corresponds to the heat generation temperature of the controller 20, is equal to or higher than the third reference value, so that the fan can be driven at a minimum level regardless of the outside air temperature. This allows the heat pump unit 1 to reduce standby power consumption while suppressing damage to the sliding parts and preventing a decrease in the reliability of the controller 20.

[0081] The fan 5 of the heat pump unit 1 does not have to be an inverter-driven fan driven by a fan motor drive inverter. That is, the fan 5 may be an AC voltage input-driven fan driven by an AC (Alternating Current) voltage.

[0082] In this way, when the heat pump device 1 of the first embodiment heats the refrigerant inside the compressor 30 while the compressor 30 is in standby mode, if the refrigerant evaporation information is equal to or greater than the reference value, it determines to rotate the fan 5 and applies voltage to the fan 5, thereby cooling the controller 20 with the fan 5. In this way, even when a refrigerant that is difficult to evaporate is used, the heat pump device 1 can prevent the reliability of the controller 20 from decreasing and prevent the refrigerant from stagnating inside the compressor 30.

[0083] Second Embodiment Next, a second embodiment will be described with reference to Fig. 5. In the second embodiment, an air conditioner, a heat pump water heater, a refrigerator, and a freezer to which the heat pump device 1 described in the first embodiment is applied will be described. The specific configurations and operations of the refrigeration cycles of the air conditioner, the heat pump water heater, the refrigerator, and the freezer according to the second embodiment will be described below.

[0084] 5 is a diagram showing a configuration example of a refrigeration cycle according to embodiment 2. The refrigeration cycle 7 according to embodiment 2 includes a compressor 71, a heat exchanger 72, an expansion mechanism 73, a receiver 74, an internal heat exchanger 75, an expansion mechanism 76, and a heat exchanger 77, which are sequentially connected by refrigerant piping to form a main refrigerant circuit 78 through which the refrigerant circulates.

[0085] In the main refrigerant circuit 78, a four-way valve 79 is provided on the discharge side of the compressor 71, allowing the direction of circulation of the refrigerant to be switched. A fan 60 is provided near the heat exchanger 77. A compression mechanism (not shown) that compresses the refrigerant and a compressor motor (not shown) that operates the compression mechanism are provided inside the compressor 71.

[0086] The refrigeration cycle 7 further includes an injection circuit 62 that connects the receiver 74 and the internal heat exchanger 75 to an injection pipe of the compressor 71 via a refrigerant piping. The injection circuit 62 is connected to the expansion mechanism 61 and the internal heat exchanger 75 in this order.

[0087] A water circuit 63 through which water circulates is connected to the heat exchanger 72. The water circuit 63 is connected to devices that use water, such as a water heater (not shown), a radiator (not shown), and a radiator (not shown) for floor heating or the like.

[0088] During heating operation, the refrigeration cycle 7 sets the four-way valve 79 in the direction of the solid line in Fig. 5. This heating operation includes not only the heating operation of an air conditioner, but also the hot water supply operation of a heat pump hot water heater in which heat is applied to water to produce hot water.

[0089] During cooling operation, the refrigeration cycle 7 sets the four-way valve 79 in the direction of the dashed line in Fig. 5. This cooling operation includes not only the cooling operation of an air conditioner, but also the production of chilled water by removing heat from water in a refrigerator, and the freezing operation of a refrigerator.

[0090] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0091] REFRIGERATION MECHANISM 1 Heat pump device, 2 Outdoor unit, 3 Indoor unit, 4 AC power supply, 5, 60 Fan, 6 Refrigerant piping, 7 Refrigeration cycle, 20 Controller, 25 Power conversion device, 30, 71 Compressor, 31 Compression element, 32 Compressor motor, 33 Outdoor heat exchanger, 34 Expansion device, 35 Indoor heat exchanger, 36, 79 Four-way valve, 40 Cooler, 41, 42 Temperature detection unit, 50 Blade, 51 Fan motor, 61, 73, 76 Expansion mechanism, 62 Injection circuit, 63 Water circuit, 72, 77 Heat exchanger, 74 Receiver, 75 Internal heat exchanger, 78 Main refrigerant circuit, 90, 93 Processing circuit, 91 Processor, 92 Memory.

Claims

1. A heat pump device comprising: a compressor that compresses a refrigerant; a heat exchanger that transfers heat of the refrigerant to air; a fan that blows air by rotating blades of a rotor; and a controller that applies a voltage to the compressor and the fan, wherein when refrigerant evaporation information, which is information corresponding to the amount of power required to vaporize the refrigerant when heating the refrigerant inside the compressor while the compressor is in standby for operation, is equal to or greater than a reference value, the controller determines to rotate the fan and applies a voltage to the fan, thereby cooling the controller with the fan.

2. The heat pump device of claim 1, wherein the refrigerant vaporization information is the amount of heating power applied by the controller to heat the refrigerant inside the compressor, the reference value is a first reference value that is a reference value for the amount of heating power, and the controller applies voltage to the fan if the amount of heating power is equal to or greater than the first reference value.

3. The heat pump device of claim 1, wherein the refrigerant evaporation information is the rate of rise of the outside air temperature outside the refrigerant circuit through which the refrigerant circulates, the reference value is a second reference value that is a reference value for the rate of rise of the outside air temperature, and the controller applies voltage to the fan if the rate of rise of the outside air temperature is equal to or greater than the second reference value.

4. The heat pump device of claim 1, further comprising a cooler that cools the controller, the refrigerant evaporation information being a cooler temperature of the cooler, the reference value being a third reference value that is a reference value for the cooler temperature, and the controller applying voltage to the fan if the cooler temperature is equal to or higher than the third reference value.

5. The heat pump device of claim 1, wherein the refrigerant evaporation information is an absolute value of the outside air temperature outside the refrigerant circuit through which the refrigerant circulates, the reference value is a fourth reference value that is a reference value for the absolute value of the outside air temperature, and the controller applies voltage to the fan if the absolute value of the outside air temperature is equal to or greater than the fourth reference value.

6. The heat pump device according to any one of claims 1 to 5, wherein the controller calculates a rotation speed of the fan based on the refrigerant evaporation information, and applies a voltage corresponding to the calculation result to the fan.

7. The heat pump apparatus according to any one of claims 1 to 6, wherein the refrigerant has a polytropic index smaller than that of a hydrofluorocarbon refrigerant.

8. The heat pump apparatus according to any one of claims 1 to 7, wherein the refrigerant is a hydrocarbon refrigerant.

9. The heat pump device according to any one of claims 1 to 8, wherein the refrigerant is R290.

10. The heat pump device according to any one of claims 1 to 9, wherein the controller stops rotation of the fan when the refrigerant evaporation information becomes smaller than a specific value.

11. An air conditioner comprising a heat pump device according to any one of claims 1 to 10.

12. A heat pump water heater comprising a heat pump device according to any one of claims 1 to 10.

13. A refrigerator comprising a heat pump device according to any one of claims 1 to 10.

14. A refrigerator comprising a heat pump device according to any one of claims 1 to 10.

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