Heat source apparatus

Abstract

The present invention provides a heat source apparatus 2 including: a hot water storage tank 10; an internal heat source 20 that heats water in the hot water storage tank 10; a first temperature sensor 30 that detects the temperature of the water in the hot water storage tank 10; a circulation pipe 40 that is connected to a lower part and an upper part of the hot water storage tank 10; a circulation pump 50; a heat pump heat source machine 70; and a controller 52. The controller 52 is configured to be capable of executing first heating control for heating the water in the hot water storage tank 10 in a state where the internal heat source 20, the circulation pump 50, and the heat pump heat source machine 70 are operating, and second heating control for heating the water in the hot water storage tank 10 in a state where the internal heat source 20 is stopped and the circulation pump 50 and the heat pump heat source machine 70 are operating. The controller 52 executes switching between the first heating control and the second heating control based on the temperature detected by the first temperature sensor 30.

Description

heat source device

[0001] The technology disclosed herein relates to a heat source device.

[0002] Japanese Patent Publication No. 60-205149 discloses a heat source device. The heat source device comprises 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 plurality of temperature sensors positioned within the hot water storage tank to detect the temperature of the water in the hot water storage tank, a circulation pipe connected to the bottom and top of the hot water storage tank, a circulation pump that sends water from the bottom of the hot water storage tank to the circulation pipe and from the circulation pipe to the top of the hot water storage tank, a heat pump heat source unit that heats the water flowing through the circulation pipe, and a control unit that controls the operation of the internal heat source, the circulation pump, and the heat pump heat source 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, the circulation pump, and the heat pump heat source 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 the heat pump heat source are operating.

[0003] 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.

[0004] The heat source device according to the first aspect disclosed in this specification may include a hot water storage tank, an internal heat source disposed above the bottommost part of the hot water storage tank in the hot water storage tank 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, a circulation pipe connected to the lower and upper parts 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 the 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 may be configured to be capable of executing a first heating control for heating the 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 operating, and a second heating control for heating the 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 operating. The control unit may execute switching between the first heating control and the second heating control based on the detected temperature of the first temperature sensor.

[0005] According to the above configuration, for example, when the detected temperature of the first temperature sensor is low, it is considered that there is a shortage of high-temperature hot water in the hot water storage tank. Therefore, by performing the first heating control, the temperature of the water in the hot water storage tank can be rapidly increased. On the other hand, when the detected temperature of the first temperature sensor is high, it can be determined that a predetermined amount of high-temperature water is stored in the hot water storage tank, and thus the control is switched to the second heating control. Thereby, the heat pump heat source machine can be effectively operated, and the temperature of the water in the hot water storage tank can be efficiently increased.

[0006] In the second aspect, in the heat source device according to the first aspect, the control unit may execute switching from the first heating control to the second heating control when the first temperature sensor detects a temperature equal to or higher than a first switching temperature during the execution of the first heating control, and may execute switching from the second heating control to the first heating control when the first temperature sensor detects a temperature equal to or lower than a second switching temperature lower than the first switching temperature during the execution of the second heating control.

[0007] 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 heating control and the second heating control can be suppressed.

[0008] In a third embodiment, in the heat source device of 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.

[0009] 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.

[0010] 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.

[0011] 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 an appropriate time.

[0012] In a fifth embodiment, in a 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.

[0013] 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 with a heat pump heat source.

[0014] 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.

[0015] 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.

[0016] This is a diagram showing the configuration of the heat source device 2 of the embodiment. This is an example flowchart of the processing performed by the controller 52 in the heat source device 2 of the embodiment. This is an example flowchart of the processing performed by the controller 52 in the heat source device 2 of the embodiment. This is a diagram schematically showing the water temperature in the hot water storage tank 10 when the third heating control is being executed in the heat source device 2 of the embodiment. This is a diagram schematically showing the water temperature in the hot water storage tank 10 when the fourth heating control is being executed in the heat source device 2 of the embodiment. This is a diagram showing the configuration of the modified heat source device 4.

[0017] Representative and non-limiting examples of the present disclosure are described below in detail with reference to the drawings. This detailed description is intended simply to show those skilled in the art details for carrying out preferred examples of the teachings and is not intended to limit the scope of the present disclosure. In addition, the disclosed additional features and teachings may be used separately from or in conjunction with other features and teachings to provide further improved heat source devices and methods of using and manufacturing the same.

[0018] Furthermore, the combinations of features and processes disclosed in the following detailed description are not essential for implementing this disclosure in the broadest sense, and are included solely to illustrate typical examples of this disclosure. Moreover, the various features of the following typical examples, as well as the various features of the various independent and dependent claims, do not necessarily have to be combined in the same way as the examples described herein, or in the order listed, to provide additional and useful embodiments of this teaching.

[0019] All features described herein and / or in the claims are intended to be disclosed individually and independently of each other, as limitations to the specific matters described in the original disclosure and in the claims, separate from the features described in the examples and / or in the claims. Furthermore, all descriptions of numerical ranges and groups or clusters are intended to disclose intermediate configurations as limitations to the specific matters described in the original disclosure and in the claims.

[0020] (Example) As shown in Figure 1, the heat source device 2 according to this example comprises a hot water storage tank 10, an internal heat source 20, a first temperature sensor 30, a second temperature sensor 32, circulation piping 40, circulation pump 50, controller 52, hot water supply piping 60, cold water supply piping 62, and a heat pump heat source unit 70. The hot water storage tank 10 is a sealed container that stores water inside and is covered on the outside with an insulating material (not shown). The capacity of the hot water storage tank 10 in this example is, for example, 100 liters.

[0021] The internal heat source 20 is installed in the middle section of the inside of the hot water storage tank 10 and is equipped with a heating element 22 that generates heat when electricity is supplied to it. The internal heat source 20 heats the water stored inside the hot water storage tank 10 by generating heat in the heating element 22. The first temperature sensor 30 is installed inside the hot water storage tank 10 above the internal heat source 20 and can detect the temperature of the water in the upper part of the hot water storage tank 10. The second temperature sensor 32 is installed inside the hot water storage tank 10 below the internal heat source 20 and can detect the temperature of the water in the lower part of the hot water storage tank 10.

[0022] The upstream end of the circulation pipe 40 is below the second temperature sensor 32 and connected to the bottom of the hot water storage tank 10. The downstream end of the circulation pipe 40 is above the first temperature sensor 30 and connected to the top of the hot water storage tank 10. The circulation pump 50 is installed in the circulation pipe 40 and pumps water in the circulation pipe 40 from the upstream side to the downstream side. When the circulation pump 50 operates, water flows from the bottom of the hot water storage tank 10 into the circulation pipe 40, and water also flows from the circulation pipe 40 to the top of the hot water storage tank 10.

[0023] The upstream end of the water supply pipe 62 is connected to a water source (not shown), such as a public water supply. The downstream end of the water supply pipe 62 is connected to the bottom of the hot water storage tank 10, below the connection point between the upstream end of the circulation pipe 40 and the hot water storage tank 10. Alternatively, the downstream end of the water supply pipe 62 may be connected to the bottom of the hot water storage tank 10, above or at the same height 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 connected to the top of 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. Alternatively, the upstream end of the hot water supply pipe 60 may be connected to the top of the hot water storage tank 10, below or at the same height 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 point (not shown), such as a faucet or shower. When the heat source device 2 supplies hot water, high-temperature water is sent from the top of the hot water storage tank 10 to the hot water supply piping 60, and low-temperature water flows from the water supply piping 62 to the bottom of the hot water storage tank 10.

[0024] 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 lowest part of the hot water storage tank 10. Furthermore, 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 highest part of the hot water storage tank 10.

[0025] 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 (for example, a fluorocarbon refrigerant) in the order of compressor, condenser, expansion valve, and evaporator, thereby absorbing heat from the outside air.

[0026] The controller 52 includes 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.

[0027] 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 (for example, 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.

[0028] 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.

[0029] 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.

[0030] 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 at its original temperature without being heated. 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.

[0031] 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 (for example, 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.

[0032] 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 (for example, 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.

[0033] 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.

[0034] 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 to heat 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] As shown in FIG. 3, in S30, the controller 52 continues the third heating control until the temperature detected by the first temperature sensor 30 becomes equal to or higher than a predetermined third switching temperature (for example, 65° C.) that is higher than the first switching temperature. When the temperature detected by the first temperature sensor 30 becomes equal to or higher than the third switching temperature (when it is YES), the process proceeds to S32.

[0045] In S32, the controller 52 restarts the operation of the circulation pump 50. As a result, 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. At the time of executing the process of S32, the internal heat source 20 is operating and the heat pump heat source machine 70 is stopped. Thus, the control for heating the water in the hot water storage tank 10 with the controller 52 stopping the heat pump heat source machine 70 and operating the circulation pump 50 and the internal heat source 20 is also referred to as the fourth heating control. That is, in S32, the controller 52 executes the switching from the third heating control to the fourth heating control. Also, both the third heating control and the fourth heating control are heating controls additionally performed after the first heating control or the second heating control is ended in S24. The third heating control and the fourth heating control together are also referred to as additional heating control.

[0046] FIG. 5 illustrates the temperature distribution of the water inside the hot water storage tank 10 when the controller 52 is executing the fourth heating control. In the fourth heating control, as the heat generating part 22 of the internal heat source 20 generates heat, the water above the internal heat source 20 is heated, and the water in the lower part of the hot water storage tank 10 flows into the upper part of the hot water storage tank 10 via the circulation pipe 40 and mixes with the water layer in the upper part of the hot water storage tank 10. For this reason, inside the hot water storage tank 10, the capacity of the high-temperature water layer increases and the capacity of the low-temperature water layer decreases, and the temperature of the high-temperature water layer decreases. After the first heating control and the second heating control are ended, the water in the lower part of the hot water storage tank 10 is at a certain high temperature, and in the fourth heating control, water at a certain high temperature is sent from the lower part of the hot water storage tank 10 to the circulation pipe 40. However, in the fourth heating control, since the heat pump heat source machine 70 is stopped, the operation of the heat pump heat source machine 70 is not adversely affected by the inflow of high-temperature water.

[0047] As shown in FIG. 3, in S34, the controller 52 determines whether or not the temperature detected by the first temperature sensor 30 is equal to or lower than a predetermined fourth switching temperature (for example, 62° C.) that is lower than the third switching temperature. If the temperature detected by the first temperature sensor 30 exceeds the fourth switching temperature (in the case of NO), the process proceeds to S36.

[0048] In S36, the controller 52 determines whether or not the temperature detected by the second temperature sensor 32 is equal to or higher than a predetermined second end temperature (for example, 65° C.) that is higher than the first end temperature. If the temperature detected by the second temperature sensor 32 is lower than the second end temperature (in the case of NO), the process returns to S34.

[0049] In S34, if the temperature detected by the first temperature sensor 30 is equal to or lower than the fourth switching temperature (in the case of YES), the process proceeds to S38. In S38, the controller 52 stops the circulation pump 50. After S38, the process returns to S30.

[0050] In S36, if the temperature detected by the second temperature sensor 32 is equal to or higher than the second end temperature (in the case of YES), the process proceeds to S40. In S40, the controller 52 determines whether or not the temperature detected by the first temperature sensor 30 is equal to or higher than the second end temperature. Usually, 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. Therefore, in this embodiment, in S40, a confirmation determination using the first temperature sensor 30 is also performed. If the temperature detected by the first temperature sensor 30 is lower than the second end temperature (in the case of NO), the process returns to S34. If the temperature detected by the first temperature sensor 30 is equal to or higher than the second end temperature (in the case of YES), the process proceeds to S42.

[0051] In S42, the controller 52 stops the operation of the circulation pump 50.

[0052] In S44, the controller 52 stops the operation of the internal heat source 20. After S44, the processes of FIGS. 2 and 3 end.

[0053] (Modification) 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).

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] (Relationship) Controller 52 is an example of a control unit.

Claims

1. The system comprises a hot water storage tank, an internal heat source positioned above the bottom of the hot water storage tank for heating the water in the tank, a first temperature sensor for detecting the temperature of the water in the 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 tank to the circulation piping and from the circulation piping to the top of the 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, wherein the control unit is 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, wherein 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 heat source device according to claim 1, wherein the control unit, while executing the first heating control, switches from the first heating control to the second heating control when the first temperature sensor detects a temperature equal to or higher than the first switching temperature, and while executing the second heating control, switches from the second heating control to the first heating control when the first temperature sensor detects a temperature equal to or lower than the second switching temperature, which is lower than the first switching temperature.

3. The heat source device according to claim 1 or 2, wherein the first temperature sensor detects the temperature of the water in the hot water storage tank above the internal heat source.

4. The heat source device according to any one of claims 1 to 3, further comprising a second temperature sensor for detecting the temperature of water sent from the bottom of the hot water storage tank to the circulation piping, wherein the control unit terminates the first heating control or the second heating control if the second temperature sensor detects a temperature equal to or higher than a first termination temperature during the execution of the first heating control or the second heating control.

5. The heat source device according to any one of claims 1 to 4, wherein the control unit is 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.

6. The heat source device according to claim 5, wherein the control unit terminates the additional heating control when the second temperature sensor detects a second termination temperature or higher, which is higher than the first termination temperature, during the execution of the additional heating control.

Images