JP2016125726A - Thermal apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of preventing a breaker from being operated due to a freezing preventive operation at a thermal apparatus capable of performing a freezing preventive operation for a tank unit and a freezing preventive operation for a heat pump unit.SOLUTION: A thermal apparatus disclosed in the specification of this invention includes a compressor, a condenser, a pressure reduction unit and an evaporator and there are provided a heat pump unit housing a heat pump for heating water through heat exchanging at the condenser and a tank unit housing a tank for storing water. In this thermal apparatus, the tank unit comprises a freezing preventive heater for heating a pipe where water flows in the tank unit. In the thermal apparatus, the number of rotation of the compressor during the freezing preventive operation is reduced as compared with that of a selection of the normal mode as the freezing preventive operation when the freezing preventive heater of the tank unit is ON under a case that the heat pump unit selects a low electrical power mode as the freezing preventive operation.SELECTED DRAWING: Figure 4

Description

  The technology disclosed in this specification relates to a thermal apparatus.

  Patent Document 1 includes a compressor, a condenser, a decompressor, and an evaporator, and a heat pump unit that houses a heat pump that heats water by heat exchange in the condenser, and a tank that stores water A thermal apparatus including the tank unit is disclosed. In this thermal apparatus, the tank unit includes a freeze prevention heater that heats a pipe through which water flows inside the tank unit. In this thermal apparatus, the freeze prevention operation can be executed in the tank unit.

JP 2014-231931 A

  In the above-described thermal equipment, not only the tank unit, but also the heat pump unit may freeze the pipe through which water flows, so it is preferable to perform the freeze prevention operation also in the heat pump unit. In the heat pump unit, even if a heater for preventing freezing is not provided, the heat pump can be used as a heat source for preventing freezing. However, if the freeze prevention operation in the tank unit and the freeze prevention operation in the heat pump unit are performed at the same time, a large amount of electric power is temporarily required for the entire thermal device. In this case, if a low-capacity breaker is used as a power source for supplying power to the tank unit and the heat pump unit, the breaker may be activated to cut off power supply to the thermal equipment.

  In this specification, the technique which solves said subject is provided. The present specification provides a technology capable of preventing a breaker from operating due to a freeze prevention operation in a thermal apparatus capable of performing a freeze prevention operation of a tank unit and a freeze prevention operation of a heat pump unit.

  The thermal equipment disclosed in this specification includes a compressor, a condenser, a decompressor, and an evaporator, and a heat pump unit that houses a heat pump that heats water by heat exchange in the condenser, and water. It is equipped with a tank unit that contains a tank to store. In the thermal device, the tank unit includes a freeze prevention heater that heats a pipe through which water flows inside the tank unit. In the thermal device, the heat pump unit can select either the normal mode or the low power mode as the freeze prevention operation. In the thermal equipment, when the low-power mode is selected as the freeze prevention operation for the heat pump unit, and when the freeze prevention heater of the tank unit is on, the normal mode is selected as the freeze prevention operation. In comparison, the rotation speed of the compressor in the freeze prevention operation is reduced. Here, “reducing the rotational speed of the compressor” includes both the case where the compressor is driven at a low rotational speed and the case where the compressor is stopped without being driven.

  According to the above thermal equipment, when the low power mode is selected as the freeze prevention operation of the heat pump unit, when the freeze prevention heater of the tank unit is on when the heat pump unit performs the freeze prevention operation, The rotational speed of the compressor is reduced as compared with the normal mode. Thereby, the electric power used in the freeze prevention operation of the heat pump unit can be suppressed to be small, and the thermal apparatus can be prevented from using large electric power as a whole. Even when a low-capacity breaker is used, it is possible to prevent the breaker from operating due to the freeze prevention operation.

  When the low-power mode is selected as the freeze prevention operation for the heat pump unit and the freeze prevention heater of the tank unit is on, the heat pump unit does not operate the compressor in the freeze prevention operation. When the freeze prevention heater of the unit is off, the compressor can be configured to operate in the freeze prevention operation.

  According to the above thermal equipment, when the freeze prevention heater of the tank unit is on, the compressor is not operated in the freeze prevention operation of the heat pump unit, and therefore the compressor is driven at a low rotation speed in the freeze prevention operation of the heat pump unit. Compared to the above, the power used can be made smaller. It is possible to reliably prevent the breaker from operating due to the freeze prevention operation.

  The above-described thermal device further includes a burner unit that houses a burner that heats water, the burner unit includes a freeze prevention heater that heats a pipe through which water flows inside the burner unit, and the heat pump unit includes: When the low power mode is selected as the freeze prevention operation and at least one of the freeze prevention heater of the tank unit and the freeze prevention heater of the burner unit is on, the normal mode is selected as the freeze prevention operation As compared with the above, it can be configured to reduce the rotational speed of the compressor in the freeze prevention operation.

  According to the above thermal equipment, the burner unit is provided separately from the tank unit, and even if the burner unit is configured to perform the freeze prevention operation using the freeze prevention heater, it is caused by the freeze prevention operation. It is possible to prevent the breaker from operating.

  When the heat pump unit is selected in the low power mode as the freeze prevention operation, the thermal apparatus described above is freezing prevention when at least one of the tank unit freeze prevention heater and the burner unit freeze prevention heater is on. The compressor can be configured to operate in the freeze prevention operation when the compressor is not operated in the operation and both the freeze prevention heater of the tank unit and the freeze prevention heater of the burner unit are off.

  According to the above thermal equipment, when the freeze prevention heater of the tank unit or the freeze prevention heater of the burner unit is on, the compressor is not operated in the freeze prevention operation of the heat pump unit. Therefore, the compressor is not operated in the freeze prevention operation of the heat pump unit. Compared with the case of driving at a low rotational speed, the power used can be made smaller. It is possible to reliably prevent the breaker from operating due to the freeze prevention operation.

  According to the technology disclosed in the present specification, it is possible to prevent the breaker from operating due to the freeze prevention operation in the thermal equipment capable of performing the freeze prevention operation of the tank unit and the freeze prevention operation of the heat pump unit.

It is a figure which shows typically the structure of the hot water supply system 2 which concerns on an Example. 6 is a table illustrating the relationship between the outside air temperature detected by the tank unit 6 and the on time and off time of the freeze prevention heater of the tank unit 6 in the hot water supply system 2 according to the example. 5 is a table illustrating the relationship between the outside air temperature detected by the burner unit 8 and the on time and off time of the freeze prevention heater of the burner unit 8 in the hot water supply system 2 according to the example. 5 is a flowchart illustrating an example of processing performed by the HP controller 24 when the normal mode is selected as the freeze prevention operation of the HP unit 4 in the hot water supply system 2 according to the embodiment. 6 is a flowchart illustrating an example of processing performed by the HP controller 24 when the low power mode is selected as the freeze prevention operation of the HP unit 4 in the hot water supply system 2 according to the embodiment. 6 is a flowchart illustrating another example of processing performed by the HP controller 24 when the low power mode is selected as the freeze prevention operation of the HP unit 4 in the hot water supply system 2 according to the embodiment.

(Example)
As shown in FIG. 1, the hot water supply system 2 according to this embodiment includes an HP (heat pump) unit 4, a tank unit 6, and a burner unit 8. The hot water supply system 2 uses the HP unit 4, the tank unit 6, and the burner unit 8 installed outdoors to supply hot water to indoor hot water supply points. The HP unit 4, the tank unit 6 and the burner unit 8 all operate with power supplied from an outdoor outlet.

The HP unit 4 is a heat source that absorbs heat from outside air and heats water. The HP unit 4 includes a heat pump 17 including a compressor 10, a condenser 12, an expansion valve 14, and an evaporator 16. The heat pump 17 absorbs heat from the outside air by circulating a refrigerant (for example, an HFC refrigerant such as R32 or R410A or a CO ₂ refrigerant such as R744) in the order of the compressor 10, the condenser 12, the expansion valve 14, and the evaporator 16. Heat the water. The compressor 10 pressurizes the refrigerant to a high temperature and a high pressure. The condenser 12 cools the refrigerant by exchanging heat with water flowing through the circulation path 19. The circulation path 19 is a path for circulating water between the tank 30 in the tank unit 6 and the condenser 12 in the HP unit 4. The expansion valve 14 depressurizes the refrigerant to low temperature and low pressure. The evaporator 16 includes a fan (not shown), and heats the refrigerant by exchanging heat with the outside air blown by the fan. The HP unit 4 further includes a circulation pump 18 that circulates water in the circulation path 19 between the tank 30 and the condenser 12, a return thermistor 20 that detects the temperature of the water flowing into the condenser 12, and water flowing out of the condenser 12. A forward thermistor 22 for detecting the temperature of the outside air, an outside temperature thermistor 23 for detecting the outside air temperature, and an HP controller 24 for controlling the operation of each component of the HP unit 4. The HP controller 24 is provided with a dip switch (not shown) for selecting whether the freeze prevention operation of the HP unit 4 is performed in the normal mode or the low power mode.

  The tank unit 6 includes a tank 30, a mixing valve 32, and a bypass control valve 34. The tank 30 is a sealed container that is covered with a heat insulating material and stores water therein. The capacity of the tank 30 of this embodiment is, for example, 100 liters. When the circulation pump 18 of the HP unit 4 is driven, water is sucked out from the bottom of the tank 30 to the circulation path 19 and sent to the condenser 12. The water heated by the condenser 12 and having a high temperature flows through the circulation path 19 and is returned from the top of the tank 30 into the tank 30. When the water heated by the HP unit 4 flows into the tank 30, a temperature stratification is formed in the tank 30 in which a high-temperature water layer is stacked on a low-temperature water layer. An upper thermistor 36 that detects the temperature of the upper water, an intermediate thermistor 37 that detects the temperature of the intermediate water, and a lower thermistor 38 that detects the temperature of the lower water are attached to the tank 30. In this embodiment, the upper thermistor 36 is disposed at a position 6 liters from the top of the tank 30, the intermediate thermistor 37 is disposed at a position 12 liters from the top of the tank 30, and the lower thermistor 38 is disposed at the tank 30. 30 liters from the top of the.

  Tap water is supplied to the tank unit 6 through the water supply path 40. In the water supply path 40, a pressure reducing valve 42 for reducing the water supply pressure and a water inlet thermistor 44 for detecting the water supply temperature are attached. The water supply path 40 branches into a tank water supply path 46 that communicates with the bottom of the tank 30 and a tank bypass path 48 that communicates with the mixing valve 32. Check valves 50 and 52 are attached to the tank water supply path 46 and the tank bypass path 48, respectively. Further, a water-side water amount sensor 54 that detects the flow rate of tap water flowing into the mixing valve 32 is attached to the tank bypass path 48. The top of the tank 30 and the mixing valve 32 communicate with each other via a tank hot water path 56. A check valve 58 and a hot water sensor 60 for detecting the flow rate of water from the tank 30 flowing into the mixing valve 32 are attached to the tank discharge path 56.

  The mixing valve 32 mixes the tap water flowing from the tank bypass passage 48 and the water from the tank 30 flowing from the tank discharge passage 56 and sends it out to the first hot water supply passage 62. The mixing valve 32 is driven by a stepping motor to adjust the opening degree on the tank bypass path 48 side (opening side on the water side) and the opening degree on the tank discharge path 56 side (opening side on the hot water side). A mixing thermistor 64 that detects the temperature of the water fed from the mixing valve 32 is attached to the first hot water supply path 62.

  Hot water is supplied from the tank unit 6 to hot water supply points such as a kitchen, a shower, and a currant through the second hot water supply path 66. A hot water supply outlet thermistor 68 that detects the temperature of water supplied to the hot water supply location and a check valve 70 are attached to the second hot water supply path 66. The first hot water supply path 62 and the second hot water supply path 66 communicate with each other through a hot water supply bypass path 72. A bypass control valve 34 is attached to the hot water supply bypass path 72.

  The tank unit 6 includes a tank controller 74 and a remote controller 76 that can communicate with the tank controller 74. The tank controller 74 controls the operation of each component of the tank unit 6. The remote control 76 is installed indoors and accepts various operation inputs from the user via switches, buttons, and the like. In addition, the remote controller 76 notifies the user of various types of information related to the settings and operations of the hot water supply system 2 by display and sound.

  The tank unit 6 further includes an outside air temperature thermistor 78 that detects the outside air temperature, and a plurality of freeze prevention heaters (not shown) provided in various pipes through which water flows inside the tank unit 6. The tank controller 74 performs the freeze prevention operation when the temperature detected by the outside air temperature thermistor 78 falls below a predetermined temperature (for example, 3 ° C.). In the freeze prevention operation in the tank unit 6, the tank controller 74 intermittently turns on / off the freeze prevention heater to heat the piping inside the tank unit 6. Thereby, it is possible to prevent water from freezing in the piping inside the tank unit 6. The ratio between the on time and the off time of the freeze prevention heater may be changed according to the outside temperature detected by the outside temperature thermistor 78. As shown in FIG. 2, in this embodiment, the lower the temperature detected by the outside air temperature thermistor 78, the longer the on time of the freeze prevention heater of the tank unit 6 and the shorter the off time. When the temperature detected by the outside temperature thermistor 78 exceeds a predetermined temperature (for example, 7 ° C.) during execution of the freeze prevention operation, the tank controller 74 ends the freeze prevention operation.

  The burner unit 8 includes a burner 80, a heat exchanger 82, a bypass servo 84, a water amount servo 86, and a hot water valve 88. The burner 80 is an auxiliary heat source machine that heats water flowing through the heat exchanger 82 by gas combustion. Water from the first hot water supply path 62 of the tank unit 6 flows into the heat exchanger 82 via the burner forward path 90. The water that has passed through the heat exchanger 82 flows out to the second hot water supply path 66 of the tank unit 6 through the burner return path 92. A water quantity servo 86 for adjusting the flow rate of water flowing through the burner forward path 90 and a water quantity sensor 91 for detecting the flow rate of water flowing through the burner forward path 90 are attached to the burner forward path 90. The burner forward path 90 and the burner return path 92 communicate with each other via a burner bypass path 94. A bypass servo 84 is attached to a connection portion between the burner forward path 90 and the burner bypass path 94. The bypass servo 84 adjusts the flow rate of water flowing from the burner forward path 90 to the burner bypass path 94. A burner hot water thermistor 96 that detects the temperature of water flowing out from the heat exchanger 82 is attached to the burner return path 92. A hot water path 98 branches off from the burner return path 92. A hot water valve 88 is attached to the hot water path 98. Hot water is poured from the burner unit 8 to the bathtub, which is a hot water supply location, via the hot water path 98. The burner unit 8 further includes a burner controller 100 that controls the operation of each component of the burner unit 8.

  The burner unit 8 further includes an outside temperature thermistor 99 that detects the outside air temperature, and a plurality of freeze prevention heaters (not shown) provided in various pipes through which water flows inside the burner unit 8. The burner controller 100 performs the freeze prevention operation when the temperature detected by the outside air temperature thermistor 99 falls below a predetermined temperature (for example, 3 ° C.). In the freeze prevention operation in the burner unit 8, the burner controller 100 intermittently turns on / off the freeze prevention heater to heat the piping inside the burner unit 8. This can prevent water from freezing in the piping inside the burner unit 8. The ratio between the on time and the off time of the freeze prevention heater may be changed according to the outside temperature detected by the outside temperature thermistor 99. As shown in FIG. 3, in this embodiment, the lower the temperature detected by the outside temperature thermistor 99, the longer the on time of the freeze prevention heater of the burner unit 8 and the shorter the off time. If the temperature detected by the outside air temperature thermistor 99 exceeds a predetermined temperature (for example, 7 ° C.) during execution of the freeze prevention operation, the burner controller 100 ends the freeze prevention operation.

  The HP controller 24 and the tank controller 74 can communicate with each other. The tank controller 74 and the burner controller 100 can communicate with each other. Therefore, the hot water supply system 2 can perform various operations such as a boiling operation and a hot water supply operation by the HP controller 24, the tank controller 74, and the burner controller 100 performing control in cooperation. Hereinafter, the HP controller 24, the tank controller 74, and the burner controller 100 are collectively referred to simply as a controller.

(Boiling operation)
In the boiling operation, the hot water supply system 2 drives the HP unit 4 to boil the water in the tank 30. The timing for starting the boiling operation can be set from various viewpoints. For example, the controller may determine the start timing of the boiling operation so that the boiling of the water in the tank 30 ends immediately before the time period in which cheap midnight power can be used ends. Alternatively, the controller determines the start timing of the boiling operation so that the boiling of the water in the tank 30 is completed immediately before the time when a large demand for hot water supply is expected based on the actual hot water supply results up to the previous day. Also good. Alternatively, the controller may start the boiling operation when the user instructs the boiling of water in the tank 30 via the remote controller 76.

  When the boiling operation is started, the controller drives the compressor 10 of the heat pump 17 to circulate the refrigerant in the order of the compressor 10, the condenser 12, the expansion valve 14, and the evaporator 16, and turns on the circulation pump 18. Driven to circulate water between the tank 30 and the condenser 12. As a result, the water sucked from the bottom of the tank 30 is heated to the boiling temperature in the condenser 12 and returned to the top of the tank 30. When all the water in the tank 30 is replaced with water heated to the boiling temperature, the controller ends the boiling operation.

(Hot water operation)
In the hot water supply operation, the hot water supply system 2 supplies hot water at a hot water supply set temperature to the hot water supply location. When the temperature of the upper part of the tank 30 detected by the upper thermistor 36 is equal to or higher than the hot water supply set temperature, the hot water supply system 2 performs a non-combustion hot water supply operation. In the non-combustion hot water supply operation, the controller prohibits the combustion operation of the burner 80 and adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 becomes the hot water supply set temperature. In this case, the high temperature water supplied from the upper part of the tank 30 and the low temperature water supplied from the water supply path 40 are mixed in the mixing valve 32, and the water adjusted to the hot water supply set temperature is supplied to the hot water supply location. The When the temperature of the upper part of the tank 30 detected by the upper thermistor 36 is less than the hot water supply set temperature, the hot water supply system 2 performs the combustion hot water supply operation. In the combustion hot water supply operation, the controller permits the burner 80 to perform the combustion operation, and mixes so that the temperature detected by the mixing thermistor 64 is lower than the hot water supply set temperature by the minimum heating capacity of the burner 80. The opening degree of the valve 32 is adjusted. In this case, the high temperature water supplied from the upper part of the tank 30 and the low temperature water supplied from the water supply path 40 are mixed in the mixing valve 32 and then heated to the hot water supply set temperature by the burner 80, so Supplied to.

(Freezing prevention operation of HP unit 4)
The HP unit 4 performs a freeze prevention operation in order to prevent the piping through which water flows such as the circulation path 19 and the condenser 12 from freezing.

  When the normal mode is selected as the freeze prevention operation of the HP unit 4, the HP controller 24 executes the process shown in FIG.

  In step S2, the HP controller 24 determines whether or not the circulation anti-freezing operation should be started. The circulation antifreeze operation is an operation in which the circulation pump 18 is driven to replace the water in the circulation path 19 and the condenser 12 with the water in the tank 30. In this embodiment, the detected temperature of the outside temperature thermistor 23 is lower than a predetermined temperature (for example, 5 ° C.), and the temperature of water in the circulation path 19 detected by the return thermistor 20 is lower than the predetermined temperature (for example, 10 ° C.). If it falls below, the HP controller 24 determines that the circulating antifreeze operation should be started.

  In step S4, the HP controller 24 drives the circulation pump 18 to perform the circulation antifreeze operation. As a result, the water inside the circulation path 19 and the condenser 12 is replaced with the water inside the tank 30. When a predetermined time (for example, 4 minutes) elapses after the circulation pump 18 is driven, the HP controller 24 ends the circulation antifreezing operation.

  In step S <b> 6, the HP controller 24 determines whether or not the heat defrosting operation should be started following the circulation defrosting operation. The heat defrosting operation is an operation of driving the circulation pump 18 and further driving the heat pump 17 to heat the water flowing through the circulation path 19 and the condenser 12. In this embodiment, when the temperature of the water in the circulation path 19 detected by the forward thermistor 22 is lower than a predetermined temperature (for example, 13 ° C.), the HP controller 24 determines that the heating defrosting operation should be started.

  If water of a certain degree of high temperature is supplied from the tank 30 to the circulation path 19 during the circulation antifreeze operation in step S4, the circulation path 19 and the condenser 12 are not likely to freeze for a while. Heated frost protection is not required. However, when low-temperature water is supplied from the tank 30 to the circulation path 19 during the circulation freeze protection operation in step S4, the circulation path 19 and the condenser 12 may continue to freeze. Therefore, in this embodiment, after the circulation antifreeze operation is performed, when the water temperature detected by the forward thermistor 22 is low, the heat antifreeze operation is executed.

  In step S8, the HP controller 24 drives the circulation pump 18 and further drives the heat pump 17 to perform the heat defrosting operation. At this time, the rotational speed of the compressor 10 is adjusted to the rotational speed set in the HP controller 24 as the rotational speed of the compressor 10 in the normal mode. As a result, the water flowing from the tank 30 to the circulation path 19 is heated by the condenser 12 and returned to the tank 30 via the circulation path 19. When the temperature detected by the outside air temperature thermistor 23 is equal to or higher than a predetermined temperature (for example, 7 ° C.) during execution of the heat defrosting operation, or the temperature of the water in the circulation path 19 detected by the return thermistor 20 is predetermined. When the temperature becomes equal to or higher than the temperature (for example, 13 ° C.), the HP controller 24 finishes the heat defrosting operation.

  When the low power mode is selected as the freeze prevention operation of the HP unit 4, the HP controller 24 executes the process shown in FIG.

  The processing performed by the HP controller 24 in steps S10, S12, and S14 is the same as steps S2, S4, and S6 in FIG.

  In step S <b> 16, the HP controller 24 determines whether or not the freeze prevention heater is turned on in the tank unit 6. If the freeze prevention heater is off in tank unit 6 (NO in step S16), the process proceeds to step S18.

  In step S18, the HP controller 24 determines whether or not the freeze prevention heater is on in the burner unit 8. If the freeze prevention heater is off in burner unit 8 (NO in step S18), the process proceeds to step S20.

  In step S20, the HP controller 24 drives the circulation pump 18 and further drives the heat pump 17 to perform the heat defrosting operation. At this time, the rotational speed of the compressor 10 is adjusted to the same rotational speed as that set in the HP controller 24 as the rotational speed of the compressor 10 in the normal mode. As a result, the water flowing from the tank 30 to the circulation path 19 is heated by the condenser 12 and returned to the tank 30 via the circulation path 19. When the temperature detected by the outside air temperature thermistor 23 is equal to or higher than a predetermined temperature (for example, 7 ° C.) during execution of the heat defrosting operation, or the temperature of the water in the circulation path 19 detected by the return thermistor 20 is predetermined. When the temperature becomes equal to or higher than the temperature (for example, 13 ° C.), the HP controller 24 finishes the heat defrosting operation.

  If the freeze prevention heater is turned on in the tank unit 6 (YES) in step S16, or if the freeze prevention heater is turned on in the burner unit 8 in step S18 (YES), the process proceeds to step S22. move on.

  In step S <b> 22, the HP controller 24 drives the circulation pump 18 and further drives the heat pump 17 to perform the heat defrosting operation. At this time, the rotational speed of the compressor 10 is adjusted to the rotational speed set in the HP controller 24 as the rotational speed of the compressor 10 in the low power mode. The rotation speed of the compressor 10 in the low power mode is set to be lower than the rotation speed of the compressor 10 in the normal mode. As a result, the water flowing from the tank 30 to the circulation path 19 is heated by the condenser 12 and returned to the tank 30 via the circulation path 19. When the temperature detected by the outside air temperature thermistor 23 is equal to or higher than a predetermined temperature (for example, 7 ° C.) during execution of the heat defrosting operation, or the temperature of the water in the circulation path 19 detected by the return thermistor 20 is predetermined. When the temperature becomes equal to or higher than the temperature (for example, 13 ° C.), the HP controller 24 finishes the heat defrosting operation.

  When the freeze prevention operation is performed in the tank unit 6 or the burner unit 8, the pipes are heated by the respective freeze prevention heaters. While these freeze prevention heaters are on, relatively large power is used. For this reason, if the freeze prevention operation is also performed in the HP unit 4 while the freeze prevention heater is on in the tank unit 6 or the burner unit 8, a large amount of electric power is temporarily used as the entire hot water supply system 2. . In this case, if a low-capacity breaker is used as a power source for supplying power to the HP unit 4, the tank unit 6, and the burner unit 8, there is a possibility that the breaker operates and the power supply to the hot water supply system 2 is interrupted. is there. Therefore, in the hot water supply system 2 of the present embodiment, it is possible to select whether the freeze prevention operation of the HP unit 4 is performed in the normal mode or the low power mode by the dip switch of the HP controller 24. The user can select in advance whether the freeze prevention operation of the HP unit 4 is performed in the normal mode or the low power mode according to the capacity of the breaker of the house where the hot water supply system 2 is installed.

  According to the processing shown in FIG. 5, when the low power mode is selected as the freeze prevention operation of the HP unit 4, the freeze prevention heater of the tank unit 6 and the freeze prevention of the burner unit 8 are performed during the heating antifreeze operation. When the heater is on, the heat defrosting operation is performed with the rotation speed of the compressor 10 set to be lower than that in the normal mode. Thereby, the electric power used in the freeze prevention operation of the HP unit 4 can be suppressed to be small, and the hot water supply system 2 can be prevented from using large electric power as a whole. Even when a low-capacity breaker is used, it is possible to prevent the breaker from operating due to the freeze prevention operation.

  When the low power mode is selected as the freeze prevention operation of the HP unit 4, the process of FIG. 6 may be performed instead of the process of FIG.

  The processing performed by the HP controller 24 in steps S24, S26, and S28 is the same as steps S2, S4, and S6 in FIG.

  In step S30, the HP controller 24 determines whether or not the freeze prevention heater is turned on in the tank unit 6. If the freeze prevention heater is turned on in tank unit 6 (YES in step S30), the process returns to step S30 without proceeding to step S32. If the freeze prevention heater is off in tank unit 6 (NO in step S30), the process proceeds to step S32.

  In step S <b> 32, the HP controller 24 determines whether or not the freeze prevention heater is on in the burner unit 8. If the freeze prevention heater is on in the burner unit 8 (YES in step S32), the process returns to step S30 without proceeding to step S34. If the freeze prevention heater is off in burner unit 8 (NO in step S32), the process proceeds to step S34.

  In step S34, the HP controller 24 drives the circulation pump 18 and further drives the heat pump 17 to perform the heat defrosting operation. At this time, the rotational speed of the compressor 10 is adjusted to the same rotational speed as that set in the HP controller 24 as the rotational speed of the compressor 10 in the normal mode. As a result, the water flowing from the tank 30 to the circulation path 19 is heated by the condenser 12 and returned to the tank 30 via the circulation path 19. When the temperature detected by the outside air temperature thermistor 23 is equal to or higher than a predetermined temperature (for example, 7 ° C.) during execution of the heat defrosting operation, or the temperature of the water in the circulation path 19 detected by the return thermistor 20 is predetermined. When the temperature becomes equal to or higher than the temperature (for example, 13 ° C.), the HP controller 24 finishes the heat defrosting operation.

  According to the processing shown in FIG. 6, when the low power mode is selected as the freeze prevention operation of the HP unit 4, the freeze prevention heater of the tank unit 6 and the freeze prevention heater of the burner unit 8 when performing the heating antifreeze operation. When is turned on, the anti-freezing operation is performed after waiting for both of these anti-freezing heaters to be turned off. As a result, when the tank unit 6 or the burner unit 8 is using a large amount of power in the freeze prevention operation, the HP unit 4 can also be prevented from performing a heating / frost protection operation using a large amount of power. Even when a low-capacity breaker is used, it is possible to prevent the breaker from operating due to the freeze prevention operation.

  In the above embodiment, when the low power mode is selected as the freeze prevention operation of the HP unit 4, one or both of the freeze prevention heater of the tank unit 6 and the freeze prevention heater of the burner unit 8 are on. The configuration for reducing the number of rotations of the compressor 10 in the heat defrosting operation has been described. On the other hand, when the low power mode is selected as the freeze prevention operation of the HP unit 4, only when both the freeze prevention heater of the tank unit 6 and the freeze prevention heater of the burner unit 8 are on, It is good also as a structure which reduces the rotation speed of the compressor 10 in a prevention operation.

  In the above embodiment, the configuration in which the tank unit 6 that accommodates the tank 30 and the burner unit 8 that accommodates the burner 80 are configured as separate units has been described. It is also possible to accommodate the components in the tank unit 6 and configure the tank unit 6 and the burner unit 8 as an integral unit.

  In the above embodiment, the configuration in which the present invention is embodied as the hot water supply system 2 that stores the water heated by the HP unit 4 in the tank unit 6 and uses it for hot water supply to the hot water supply location has been described. You may embody this invention as a heating system which stores the water heated by the unit 4 in the tank unit 6, and uses it for the heating to a heating location.

  As shown in FIG. 1, a hot water supply system 2 (corresponding to a thermal device) of the present embodiment includes a compressor 10, a condenser 12, an expansion valve 14 (corresponding to a decompressor), and an evaporator 16. And an HP unit 4 that houses a heat pump 17 that heats water by heat exchange in the condenser 12 and a tank unit 6 that houses a tank 30 for storing water. The tank unit 6 includes a freeze prevention heater that heats a pipe through which water flows inside the tank unit 6. The HP unit 4 can select either the normal mode or the low power mode as the freeze prevention operation. As shown in FIGS. 5 and 6, when the low power mode is selected as the freeze prevention operation, the HP unit 4 is in the normal mode as the freeze prevention operation when the freeze prevention heater of the tank unit 6 is on. Compared with the case where it is selected, the rotation speed of the compressor 10 in the freeze prevention operation is reduced.

  As shown in FIG. 6, when the low power mode is selected as the freeze prevention operation, the HP unit 4 operates the compressor 10 in the freeze prevention operation when the freeze prevention heater of the tank unit 6 is on. If the freeze prevention heater of the tank unit 6 is off, the compressor 10 is operated in the freeze prevention operation.

  As shown in FIG. 1, the hot water supply system 2 further includes a burner unit 8 that houses a burner 80 that heats water. The burner unit 8 includes a freeze prevention heater that heats a pipe through which water flows inside the burner unit 8. As shown in FIGS. 5 and 6, in the HP unit 4, at least one of the freeze prevention heater of the tank unit 6 and the freeze prevention heater of the burner unit 8 is turned on when the low power mode is selected as the freeze prevention operation. If this is the case, the rotational speed of the compressor 10 in the freeze prevention operation is reduced as compared with the case where the normal mode is selected as the freeze prevention operation.

  As shown in FIG. 6, when the low power mode is selected as the freeze prevention operation, the HP unit 4 has at least one of the freeze prevention heater of the tank unit 6 and the freeze prevention heater of the burner unit 8 turned on. Furthermore, when the compressor 10 is not operated in the freeze prevention operation and both the freeze prevention heater of the tank unit 6 and the freeze prevention heater of the burner unit 8 are off, the compressor 10 is operated in the freeze prevention operation.

  Each embodiment has been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: Hot water supply system 4: HP unit 6: Tank unit 8: Burner unit 10: Compressor 12: Condenser 14: Expansion valve 16: Evaporator 17: Heat pump 18: Circulation pump 19: Circulation path 20: Return thermistor 22: Outward Thermistor 23: Outside temperature thermistor 24: HP controller 30: Tank 32: Mixing valve 34: Bypass control valve 36: Upper thermistor 37: Intermediate thermistor 38: Lower thermistor 40: Water supply path 42: Pressure reducing valve 44: Incoming thermistor 46: Tank Water supply path 48: Tank bypass path 50: Check valve 52: Check valve 54: Water side water quantity sensor 56: Tank hot water path 58: Check valve 60: Hot water side water quantity sensor 62: First hot water supply path 64: Mixing thermistor 66 : Second hot water supply path 68: Hot water supply outlet thermistor 70: Check valve 72: Hot water bypass path 74: Tank controller 76: Remote controller 78: Outside temperature thermistor 80: Burner 82: Heat exchanger 84: Bypass servo 86: Water quantity servo 88: Hot water valve 90: Burner forward path 91: Water quantity sensor 92: Burner return path 94: Burner bypass path 96: Burner hot water supply thermistor 98: Hot water path 99: Outside temperature thermistor 100: Burner controller

Claims (4)

A heat pump unit including a compressor, a condenser, a decompressor, and an evaporator, and containing a heat pump that heats water by heat exchange in the condenser;
It has a tank unit that contains a tank for storing water,
The tank unit is equipped with a freeze prevention heater that heats the piping through which water flows inside the tank unit.
The heat pump unit can select either normal mode or low power mode as freeze prevention operation,
When the low-power mode is selected as the freeze prevention operation, the heat pump unit has the freeze prevention operation when the tank unit freeze prevention heater is on compared to when the normal mode is selected as the freeze prevention operation. Thermal equipment that reduces the number of compressor revolutions in   When the low power mode is selected for the freeze prevention operation and the freeze prevention heater of the tank unit is on, the heat pump unit does not operate the compressor in the freeze prevention operation and the freeze prevention heater of the tank unit The thermal device of claim 1, wherein when it is off, the compressor is operated in a freeze prevention operation. It further comprises a burner unit containing a burner for heating water,
The burner unit is equipped with a freeze prevention heater that heats the piping through which water flows inside the burner unit.
When the low-power mode is selected as the freeze prevention operation, the heat pump unit selects the normal mode as the freeze prevention operation when at least one of the freeze prevention heater of the tank unit and the freeze prevention heater of the burner unit is on. The thermal apparatus according to claim 1, wherein the number of rotations of the compressor in the freeze prevention operation is reduced as compared with a case where the operation is performed.   The heat pump unit operates the compressor in the freeze prevention operation when at least one of the freeze prevention heater of the tank unit and the freeze prevention heater of the burner unit is on when the low power mode is selected as the freeze prevention operation. The thermal apparatus according to claim 3, wherein the compressor is operated in the freeze prevention operation when both the freeze prevention heater of the tank unit and the freeze prevention heater of the burner unit are off.

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