Heat source device

Abstract

This technology provides the ability to effectively operate a heat pump heat source unit and efficiently raise the temperature of the water in the hot water storage tank. [Solution] The heat source device comprises a hot water storage tank, an internal heat source for heating the water in the hot water storage tank, a first temperature sensor for detecting the temperature of the water in the hot water storage tank, circulation piping connected to the lower and upper parts of the hot water storage tank, a circulation pump, a heat pump heat source unit, and a control unit. The control unit is configured to perform a first heating control, which heats the water in the hot water storage tank while the internal heat source, circulation pump, and heat pump heat source unit are operating, and a second heating control, which heats the water in the hot water storage tank while the internal heat source is stopped and the circulation pump and heat pump heat source unit are operating. The control unit switches between the first heating control and the second heating control based on the temperature detected by the first temperature sensor.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a heat source device.

Background Art

[0002] Patent Document 1 discloses a heat source device. The heat source device includes a hot water storage tank, an internal heat source disposed above the lowermost part of the hot water storage tank in the hot water storage tank for heating water in the hot water storage tank, a plurality of temperature sensors for detecting the temperature of water in the hot water storage tank in the hot water storage tank, a circulation pipe connected to the lower part and the upper part of the hot water storage tank, a circulation pump for sending water from the lower part of the hot water storage tank to the circulation pipe and sending water from the circulation pipe to the upper part of the hot water storage tank, a heat pump heat source machine for heating water flowing through the circulation pipe, and a control unit for controlling the operations of the internal heat source, the circulation pump, and the heat pump heat source machine. The control unit is configured to be capable of executing a first heating control for heating water in the hot water storage tank in a state where the internal heat source, the circulation pump, and the heat pump heat source machine are operated, and a second heating control for heating water in the hot water storage tank in a state where the internal heat source is stopped and the circulation pump and the heat pump heat source machine are operated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the heat source device described above, when performing the first heating control, which involves heating the water with an internal heat source, the water in the hot water storage tank can be heated more quickly than when performing the second heating control, which does not involve heating the water with an internal heat source. However, when performing the first heating control, which involves heating the water with an internal heat source, high-temperature water may be sent from the bottom of the hot water storage tank to the heat pump heat source unit. If high-temperature water flows into the heat pump heat source unit, it may reduce the energy efficiency of the heat pump heat source unit or cause the heat pump heat source unit to stop operating. In this case, the temperature of the water in the hot water storage tank will not reach the temperature desired by the user, so the temperature of the water in the hot water storage tank will be raised by the internal heat source alone. If the energy efficiency of the internal heat source is worse than the energy efficiency of the heat pump heat source unit, energy will be wasted. This specification provides a technology that enables the heat pump heat source unit to be operated effectively and the water in the hot water storage tank to be heated efficiently. [Means for solving the problem]

[0005] A heat source device according to a first embodiment disclosed herein may include: a hot water storage tank; an internal heat source positioned above the bottom of the hot water storage tank and heating the water in the hot water storage tank; a first temperature sensor for detecting the temperature of the water in the hot water storage tank; circulation piping connected to the bottom and top of the hot water storage tank; a circulation pump for sending water from the bottom of the hot water storage tank to the circulation piping and from the circulation piping to the top of the hot water storage tank; a heat pump heat source unit for heating the water flowing through the circulation piping; and a control unit for controlling the operation of the internal heat source, the circulation pump, and the heat pump heat source unit. The control unit may be configured to perform a first heating control for heating the water in the hot water storage tank while the internal heat source, the circulation pump, and the heat pump heat source unit are operating; and a second heating control for heating the water in the hot water storage tank while the internal heat source is stopped and the circulation pump and the heat pump heat source unit are operating. The control unit may switch between the first heating control and the second heating control based on the temperature detected by the first temperature sensor.

[0006] With the above configuration, for example, if the temperature detected by the first temperature sensor is low, it is assumed that there is insufficient high-temperature water in the hot water storage tank, and the first heating control is performed to quickly raise the temperature of the water in the hot water storage tank. On the other hand, if the temperature detected by the first temperature sensor is high, it is determined that a predetermined amount of high-temperature water is stored in the hot water storage tank, and the system switches to the second heating control. This allows the heat pump heat source to operate effectively and efficiently raise the temperature of the water in the hot water storage tank.

[0007] In a second embodiment, in the heat source device of the first embodiment, the control unit may switch from the first heating control to the second heating control if the first temperature sensor detects a temperature of or above the first switching temperature while the first heating control is being executed, or may switch from the second heating control to the first heating control if the first temperature sensor detects a temperature of or below the second switching temperature, which is lower than the first switching temperature, while the second heating control is being executed.

[0008] With the above configuration, the second switching temperature, which is the threshold for switching from the second heating control to the first heating control, is set to a lower temperature than the first switching temperature, which is the threshold for switching from the first heating control to the second heating control. Therefore, frequent switching between the first and second heating controls can be suppressed.

[0009] In a third embodiment, in the heat source device according to any one of the first to second embodiments described above, the first temperature sensor may detect the temperature of the water in the hot water storage tank located above the internal heat source.

[0010] With the above configuration, the temperature of the water in the hot water storage tank, which is heated by both the internal heat source and the heat pump heat source unit, can be detected with high accuracy.

[0011] In a fourth embodiment, the heat source device according to any one of the first to third embodiments may further include a second temperature sensor for detecting the temperature of the water sent from the bottom of the hot water storage tank to the circulation piping. The control unit may terminate the first heating control or the second heating control if the second temperature sensor detects a temperature equal to or higher than the first termination temperature while the first heating control or the second heating control is being executed.

[0012] With the above configuration, the heating of the water in the hot water storage tank by the first heating control and the second heating control can be terminated at the appropriate timing.

[0013] In the fifth embodiment, in the heat source device according to any one of the first to fourth embodiments described above, the control unit may be configured to perform additional heating control, which involves operating the internal heat source and heating the water in the hot water storage tank after the first heating control or the second heating control has been completed and the heat pump heat source unit has been stopped.

[0014] With the above configuration, for example, if the water in the hot water storage tank has been heated to its full temperature but has not reached the temperature desired by the user, the water in the hot water storage tank can be heated to a higher temperature by performing additional heating control that does not involve heating the water by the heat pump heat source.

[0015] In the sixth embodiment, in the heat source device of the fifth embodiment, the control unit may terminate the additional heating control if the second temperature sensor detects a second termination temperature or higher that is higher than the first termination temperature while the additional heating control is being executed.

[0016] With the above configuration, the heating of the water in the hot water storage tank by additional heating control can be terminated at the appropriate time. [Brief explanation of the drawing]

[0017] [Figure 1] This diagram shows the configuration of the heat source device 2 in the embodiment. [Figure 2]This is an example of a flowchart of the processing performed by the controller 52 in the heat source device 2 of the embodiment. [Figure 3] This is an example of a flowchart of the processing performed by the controller 52 in the heat source device 2 of the embodiment. [Figure 4] This is a diagram schematically showing the temperature of the water in the hot water storage tank 10 when the third heating control is being executed in the heat source device 2 of the embodiment. [Figure 5] This is a diagram schematically showing the temperature of the water in the hot water storage tank 10 when the fourth heating control is being executed in the heat source device 2 of the embodiment. [Figure 6] This is a diagram showing the configuration of the heat source device 4 of the modified example.

Mode for Carrying Out the Invention

[0018] (Embodiment) As shown in FIG. 1, the heat source device 2 according to the embodiment includes a hot water storage tank 10, an internal heat source 20, a first temperature sensor 30, a second temperature sensor 32, a circulation pipe 40, a circulation pump 50, a controller 52, a hot water supply pipe 60, a water supply pipe 62, and a heat pump heat source machine 70. The hot water storage tank 10 is covered with a heat insulating material (not shown) on the outside and is a sealed container for storing water inside. The capacity of the hot water storage tank 10 in this embodiment is, for example, 100 liters.

[0019] The internal heat source 20 is installed in the middle part inside the hot water storage tank 10 and includes a heat generating part 22 that generates heat when power is supplied. The internal heat source 20 heats the water stored inside the hot water storage tank 10 by the heat generating part 22 generating heat. The first temperature sensor 30 is installed above the internal heat source 20 inside the hot water storage tank 10 and can detect the temperature of the water at the upper part of the hot water storage tank 10. The second temperature sensor 32 is installed below the internal heat source 20 inside the hot water storage tank 10 and can detect the temperature of the water at the lower part of the hot water storage tank 10.

[0020] The upstream end of the circulation pipe 40 is below the second temperature sensor 32 and is connected to the lower part of the hot water storage tank 10. The downstream end of the circulation pipe 40 is above the first temperature sensor 30 and is connected to the upper part of the hot water storage tank 10. The circulation pump 50 is provided in the circulation pipe 40 and pumps the water in the circulation pipe 40 from the upstream side to the downstream side. When the circulation pump 50 operates, water flows from the lower part of the hot water storage tank 10 into the circulation pipe 40 and water flows from the circulation pipe 40 into the upper part of the hot water storage tank 10.

[0021] The upstream end of the water supply pipe 62 is connected to a water supply source (not shown) such as a water supply. The downstream end of the water supply pipe 62 is below the connection point between the upstream end of the circulation pipe 40 and the hot water storage tank 10 and is connected to the lower part of the hot water storage tank 10. Note that the downstream end of the water supply pipe 62 may be connected to the lower part of the hot water storage tank 10 at a height above or the same as the connection point between the upstream end of the circulation pipe 40 and the hot water storage tank 10. The upstream end of the hot water supply pipe 60 is above the connection point between the downstream end of the circulation pipe 40 and the hot water storage tank 10 and is connected to the upper part of the hot water storage tank 10. Note that the upstream end of the hot water supply pipe 60 may be connected to the upper part of the hot water storage tank 10 at a height below or the same as the connection point between the downstream end of the circulation pipe 40 and the hot water storage tank 10. The downstream end of the hot water supply pipe 60 is connected to a hot water supply location (not shown) such as a faucet or a shower. When the heat source device 2 supplies hot water, high-temperature water is sent from the upper part of the hot water storage tank 10 into the hot water supply pipe 60 and low-temperature water flows from the water supply pipe 62 into the lower part of the hot water storage tank 10.

[0022] In this embodiment, the connection point between the upstream end of the circulation pipe 40 and the hot water storage tank 10 and the connection point between the downstream end of the water supply pipe 62 and the hot water storage tank 10 are located above the lowermost part of the hot water storage tank 10. Also, the connection point between the downstream end of the circulation pipe 40 and the hot water storage tank 10 and the connection point between the upstream end of the hot water supply pipe 60 and the hot water storage tank 10 are located below the uppermost part of the hot water storage tank 10.

[0023] The heat pump heat source unit 70 uses electricity to absorb heat from the outside air and heat the water flowing through the circulation pipe 40. The specific configuration of the heat pump heat source unit 70 is not particularly limited. For example, the heat pump heat source unit 70 includes a compressor (not shown), a condenser, an expansion valve, and an evaporator. The heat pump heat source unit 70 heats the water flowing through the circulation pipe 40 by circulating a refrigerant (e.g., a fluorocarbon refrigerant) in the order of compressor, condenser, expansion valve, and evaporator, thereby absorbing heat from the outside air.

[0024] The controller 52 is equipped with a CPU, ROM, RAM, etc. The controller 52 controls the operation of the heat source device 2 by executing various processes according to the program stored in the ROM.

[0025] When power is supplied to the heat source device 2, the controller 52 executes the processes shown in Figures 2 and 3. In S8, the controller 52 waits until the first temperature sensor 30 detects a temperature below a predetermined heating start temperature (e.g., 45°C). When the first temperature sensor 30 detects a temperature below the heating start temperature (YES), the process proceeds to S10. Note that the process in S8 may be omitted. That is, when power is supplied to the heat source device 2, the processes from S10 onwards may be executed regardless of the heating start temperature.

[0026] In S10 shown in Figure 2, the controller 52 starts the operation of the circulation pump 50 and the heat pump heat source unit 70. As a result, water flows from the bottom of the hot water storage tank 10 into the circulation piping 40, and water heated by the heat pump heat source unit 70 flows from the circulation piping 40 into the top of the hot water storage tank 10.

[0027] In S12, the controller 52 starts the operation of the internal heat source 20. As a result, the water inside the hot water storage tank 10 is also heated by the internal heat source 20. This control by the controller 52 to operate the internal heat source 20, the circulation pump 50, and the heat pump heat source unit 70 to heat the water inside the hot water storage tank 10 is also called the first heating control.

[0028] In the first heating control, the heating element 22 of the internal heat source 20 generates heat, causing the water above the internal heat source 20 to heat up and its temperature to rise. On the other hand, the water below the internal heat source 20 remains unheated and is maintained at its original temperature. The heating of the water by the internal heat source 20 creates a temperature stratification inside the hot water storage tank 10, where a layer of high-temperature water is stacked on top of a layer of low-temperature water. Simultaneously, in the first heating control, the circulation pump 50 and the heat pump heat source unit 70 operate, causing the water from the lower part of the hot water storage tank 10 to flow into the upstream side of the circulation pipe 40 and be heated by the heat pump heat source unit 70. The heated water flows back into the upper part of the hot water storage tank 10 from the downstream side of the circulation pipe 40, mixing with the high-temperature water layer at the top of the hot water storage tank 10. As a result, the volume of the high-temperature water layer inside the hot water storage tank 10 increases and the volume of the low-temperature water layer decreases. By executing the first heating control, the heat source device 2 can rapidly raise the temperature of the water in the hot water storage tank 10.

[0029] In S14, the controller 52 determines whether the temperature detected by the second temperature sensor 32 is equal to or greater than a predetermined first termination temperature (e.g., 60°C). If the temperature detected by the second temperature sensor 32 is less than the predetermined first termination temperature (NO), the process proceeds to S16.

[0030] In S16, the controller 52 determines whether the temperature detected by the first temperature sensor 30 is equal to or greater than a predetermined first switching temperature (e.g., 60°C). If the temperature detected by the first temperature sensor 30 is less than the predetermined first switching temperature (NO), the process returns to S14.

[0031] In S16, if the temperature detected by the first temperature sensor 30 is above a predetermined first switching temperature (YES), the process proceeds to S20. At this time, a predetermined amount of high-temperature water desired by the user is formed in the upper part of the hot water storage tank 10 by the first heating control.

[0032] In S20, the controller 52 stops the operation of the internal heat source 20. Even after the operation of the internal heat source 20 stops in S20, the circulation pump 50 and the heat pump heat source unit 70 continue to operate. This control, in which the controller 52 stops the internal heat source 20 and operates the circulation pump 50 and the heat pump heat source unit 70 while heating the water in the hot water storage tank 10, is also called the second heating control. In other words, in S20, the controller 52 switches from the first heating control to the second heating control based on the temperature detected by the first temperature sensor.

[0033] In the second heating control, the circulation pump 50 and the heat pump heat source unit 70 operate, causing the water from the bottom of the hot water storage tank 10 to flow into the upstream side of the circulation pipe 40 and be heated by the heat pump heat source unit 70. The heated water then flows back into the top of the hot water storage tank 10 from the downstream side of the circulation pipe 40, mixing with the high-temperature water layer at the top of the hot water storage tank 10. As a result, the volume of the high-temperature water layer inside the hot water storage tank 10 increases while the volume of the low-temperature water layer decreases. In other words, the water below the first temperature sensor inside the hot water storage tank 10 can be heated more efficiently by effectively operating the heat pump heat source unit 70 than in the first heating control, which operates the internal heat source 20.

[0034] In S22, the controller 52 determines whether the temperature detected by the second temperature sensor 32 is equal to or greater than a predetermined first termination temperature. If the temperature detected by the second temperature sensor 32 is less than the predetermined first termination temperature (NO), the process proceeds to S26.

[0035] In S26, the controller 52 determines whether the temperature detected by the first temperature sensor 30 is below a predetermined second switching temperature (for example, 55°C). If the temperature detected by the first temperature sensor 30 exceeds the predetermined second switching temperature (NO), the process returns to S22.

[0036] In S26, if the temperature detected by the first temperature sensor 30 falls below a predetermined second switching temperature (YES), the process returns to S12, and the controller 52 starts the operation of the internal heat source 20. That is, in S12, the controller 52 switches from the second heating control to the first heating control based on the temperature detected by the first temperature sensor 30.

[0037] As described above, at the time of processing in S14, the controller 52 is executing the first heating control. If the temperature detected by the second temperature sensor 32 in S14 is equal to or greater than the predetermined first termination temperature (YES), the process proceeds to S18. In S18, the controller 52 stops the operation of the internal heat source 20. After that, the process proceeds to S24.

[0038] As described above, at the time of processing in S22, the controller 52 is executing the second heating control. If the temperature detected by the second temperature sensor 32 in S22 is equal to or greater than the predetermined first termination temperature (YES), the process proceeds to S24.

[0039] In S24, the controller 52 stops the operation of the circulation pump 50 and the heat pump heat source unit 70. This terminates the first or second heating control that the controller 52 was performing.

[0040] After S24, the process proceeds to S28 as shown in Figure 3. In S28, the controller 52 restarts the operation of the internal heat source 20. Note that when the operation of the internal heat source 20 is restarted in S28, the circulation pump 50 and the heat pump heat source unit 70 are stopped. This control, in which the controller 52 stops the circulation pump 50 and the heat pump heat source unit 70 and operates the internal heat source 20 to heat the water in the hot water storage tank 10, is also called the third heating control.

[0041] Figure 4 illustrates the temperature distribution of the water inside the hot water storage tank 10 when the controller 52 is performing the third heating control. In the third heating control, the heating element 22 of the internal heat source 20 generates heat, causing the water above the internal heat source 20 to heat up and its temperature to rise. On the other hand, the water below the internal heat source 20 is not heated and remains at its original temperature.

[0042] As shown in Figure 3, in S30, the controller 52 continues the third heating control until the temperature detected by the first temperature sensor 30 reaches a predetermined third switching temperature (e.g., 65°C) or higher, which is higher than the first switching temperature. When the temperature detected by the first temperature sensor 30 reaches or exceeds the third switching temperature (YES), the process proceeds to S32.

[0043] In S32, the controller 52 restarts the operation of the circulation pump 50. This causes water to flow from the bottom of the hot water storage tank 10 into the circulation pipe 40, and from the circulation pipe 40 to the top of the hot water storage tank 10. At the time the process in S32 is executed, the internal heat source 20 is operating, and the heat pump heat source unit 70 is stopped. This control, in which the controller 52 stops the heat pump heat source unit 70 and operates the circulation pump 50 and internal heat source 20 to heat the water in the hot water storage tank 10, is also called the fourth heating control. In other words, in S32, the controller 52 switches from the third heating control to the fourth heating control. Both the third and fourth heating controls are additional heating controls performed after the first or second heating control is completed in S24. The third and fourth heating controls together are also called additional heating controls.

[0044] Figure 5 illustrates the temperature distribution of the water inside the hot water storage tank 10 when the controller 52 is performing the fourth heating control. In the fourth heating control, the heating element 22 of the internal heat source 20 generates heat, heating the water above the internal heat source 20, while the water from the bottom of the hot water storage tank 10 flows into the top of the hot water storage tank 10 via the circulation pipe 40 and mixes with the water layer at the top of the hot water storage tank 10. As a result, the volume of the high-temperature water layer increases and the volume of the low-temperature water layer decreases inside the hot water storage tank 10, and the temperature of the high-temperature water layer decreases. After the first and second heating control are completed, the water at the bottom of the hot water storage tank 10 is at a certain temperature, and in the fourth heating control, water at a certain temperature is sent from the bottom of the hot water storage tank 10 to the circulation pipe 40. However, since the heat pump heat source unit 70 is stopped in the fourth heating control, the inflow of high-temperature water does not adversely affect the operation of the heat pump heat source unit 70.

[0045] As shown in Figure 3, in S34, the controller 52 determines whether the temperature detected by the first temperature sensor 30 is below a predetermined fourth switching temperature (e.g., 62°C), which is lower than the third switching temperature. If the temperature detected by the first temperature sensor 30 exceeds the fourth switching temperature (NO), the process proceeds to S36.

[0046] In S36, the controller 52 determines whether the temperature detected by the second temperature sensor 32 is higher than the first termination temperature, specifically a predetermined second termination temperature (e.g., 65°C). If the temperature detected by the second temperature sensor 32 is lower than the second termination temperature (NO), the process returns to S34.

[0047] In S34, if the temperature detected by the first temperature sensor 30 is below the fourth switching temperature (YES), the process proceeds to S38. In S38, the controller 52 stops the circulation pump 50. After S38, the process returns to S30.

[0048] In S36, if the temperature detected by the second temperature sensor 32 is equal to or greater than the second end temperature (YES), the process proceeds to S40. In S40, the controller 52 determines whether the temperature detected by the first temperature sensor 30 is equal to or greater than the second end temperature. Normally, a temperature stratification is formed inside the hot water storage tank 10, so the temperature detected by the first temperature sensor 30 should be higher than the temperature detected by the second temperature sensor 32. However, if the temperature stratification of the water inside the hot water storage tank 10 is disturbed for some reason, the temperature detected by the first temperature sensor 30 may be lower than the temperature detected by the second temperature sensor 32. For this reason, in this embodiment, a confirmation determination is also made using the first temperature sensor 30 in S40. If the temperature detected by the first temperature sensor 30 is lower than the second end temperature (NO), the process returns to S34. If the temperature detected by the first temperature sensor 30 is equal to or greater than the second end temperature (YES), the process proceeds to S42.

[0049] In S42, the controller 52 stops the operation of the circulation pump 50.

[0050] In S44, the controller 52 stops the operation of the internal heat source 20. After S44, the processes shown in Figures 2 and 3 are completed.

[0051] (modified version) The heat source device 2 may be equipped with a third temperature sensor 34 inside the hot water storage tank 10, above the connection point between the downstream end of the circulation pipe 40 and the hot water storage tank 10, as shown in the heat source device 4 in Figure 6. When such a heat source device 4 performs heating control as shown in Figures 2 and 3, the controller 52 may make the decision in S26 (or S34) based on whether the temperature detected by the third temperature sensor 34 is below a predetermined second switching temperature (or fourth switching temperature).

[0052] The second temperature sensor 32 inside the hot water storage tank 10 may be installed in the circulation piping 40, as shown in the heat source device 4 in Figure 6.

[0053] The heat source device 2 may further include a heat source unit installed in the circulation piping 40 in addition to the heat pump heat source unit 70. For example, the heat source device 2 may further include a gas heat source unit or a solar heat source unit installed in the circulation piping 40.

[0054] The internal heat source 20 does not have to be configured to generate heat through power supply. For example, the internal heat source 20 may be a heat exchanger through which a high-temperature heat transfer medium flows. In this case, the heat exchanger is positioned to pass through the inside of the hot water storage tank 10 and heats the water inside the hot water storage tank 10 through heat exchange with the high-temperature heat transfer medium.

[0055] The first termination temperatures in S14 and S22 in Figure 2 may be the same as or different from the first switching temperature in S16. Similarly, the second termination temperatures in S36 and S40 in Figure 3 may be the same as or different from the third switching temperature in S30. The first switching temperature or the third switching temperature may be a fixed value or not. For example, the first switching temperature or the third switching temperature may be a temperature that is a predetermined value lower than the first or second termination temperature.

[0056] The process shown in Figure 3 may be configured to be executed when the heating capacity of the heat pump heat source is insufficient to reach the user's desired set temperature.

[0057] (Correspondence) Controller 52 is an example of a control unit.

[0058] The technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of Symbols]

[0059] 2, 4: Heat source device 10: Hot water storage tank 20: Internal heat source 22: Heat-generating part 30: First temperature sensor 32: Second temperature sensor 34: Third temperature sensor 40: Circulation piping 50: Circulation pump 52: Controller 60: Hot water piping 62: Water supply piping 70: Heat pump heat source unit

Claims

1. Hot water storage tank and Within the hot water storage tank, an internal heat source is positioned above the lowest part of the hot water storage tank and heats the water in the hot water storage tank, A first temperature sensor for detecting the temperature of the water in the hot water storage tank, The circulation piping connected to the lower and upper parts of the aforementioned hot water storage tank, A circulation pump that sends water from the bottom of the hot water storage tank to the circulation piping and from the circulation piping to the top of the hot water storage tank, A heat pump heat source unit that heats the water flowing through the aforementioned circulation pipe, It comprises the internal heat source, the circulation pump, and a control unit that controls the operation of the heat pump heat source unit. The control unit, With the internal heat source, the circulation pump, and the heat pump heat source unit in operation, a first heating control is performed to heat the water in the hot water storage tank, The system is configured to perform a second heating control, which involves stopping the internal heat source and operating the circulation pump and the heat pump heat source unit while heating the water in the hot water storage tank. The control unit switches between the first heating control and the second heating control based on the temperature detected by the first temperature sensor. Heat source device.

2. The control unit, During the execution of the first heating control, if the first temperature sensor detects a temperature above the first switching temperature, a switch from the first heating control to the second heating control is performed. During the execution of the second heating control, if the first temperature sensor detects a second switching temperature or lower than the first switching temperature, the system will switch from the second heating control to the first heating control. The heat source device according to claim 1.

3. The first temperature sensor detects the temperature of the water in the hot water storage tank above the internal heat source. The heat source device according to claim 1.

4. The system further includes a second temperature sensor for detecting the temperature of the water sent from the bottom of the hot water storage tank to the circulation piping, The control unit, If the second temperature sensor detects a temperature equal to or higher than the first termination temperature while the first heating control or the second heating control is being executed, the first heating control or the second heating control is terminated. The heat source device according to claim 1.

5. The control unit, After the first heating control or the second heating control has been completed, the system is configured to perform an additional heating control, which involves operating the internal heat source to heat the water in the hot water storage tank while the heat pump heat source unit is stopped. The heat source device according to claim 4.

6. The control unit, During the execution of the additional heating control, if the second temperature sensor detects a second termination temperature or higher than the first termination temperature, the additional heating control is terminated. The heat source device according to claim 5.

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