JP5462007B2 - Solar water heater - Google Patents

Description

  The present invention relates to a solar water heater. In particular, the present invention relates to a solar water heater that can inspect the circulation state of a heat medium in a heat medium circulation pipe that circulates the heat medium between a solar heat collector and a hot water storage tank.

  Conventionally, a solar heat collector that heats a heat medium using solar heat, a hot water storage tank, a heat medium circulation conduit that circulates the heat medium between the solar heat collector and the hot water storage tank, and a downstream side of the hot water storage tank There is known a solar water heater equipped with an auxiliary heat source device such as a water heater for heating hot water discharged from a hot water storage tank to a predetermined temperature. In this type of solar water heater, a heat medium heated by a solar heat collector is guided to a hot water storage tank through a heat medium circulation pipe, and heat is exchanged between the water supplied in the hot water tank and the heated heat medium. If the temperature of the hot water in the hot water tank heated by the heat medium is low, the auxiliary heat source unit is activated during the hot water supply operation, and the hot water heated to a predetermined temperature is supplied to the outlet terminal. (For example, Patent Document 1).

JP 2003-148804 A

  By the way, in the above solar water heater, a circulation pump is provided in the heat medium circulation pipe and the circulation medium is driven to circulate the heat medium. However, the capacity of the circulation pump has decreased due to deterioration over time. It is desirable to periodically inspect the circulation state of the heat medium in the heat medium circulation pipe in preparation for cases or when the heat medium circulation pipe is clogged.

  When inspecting the circulation state of such a heat medium, a heat medium temperature detection unit such as a temperature sensor is provided in the solar heat collector or the heat medium circulation pipe, and within the inspection time detected by the heat medium temperature detection unit. It is conceivable to determine the circulation state of the heat medium by comparing the temperature difference between the two.

  However, the solar heat collector is low in heat collection efficiency, and therefore the temperature change of the heat medium is small, so that detection errors are likely to occur. Therefore, there is a problem that it is difficult to accurately determine the circulation state of the heat medium only by detecting the temperature of the heat medium in the solar heat collector or the heat medium circulation pipe. In addition, since the amount of heat collected by the solar heat collector depends on the amount of solar radiation, there is a problem that the temperature of the heat medium does not rise and the circulation state of the heat medium cannot be inspected when the amount of solar radiation is low, such as at night or in the rain. There is.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to circulate the heat medium in the heat medium circulation pipe that circulates the heat medium between the solar heat collector and the hot water storage tank. It is an object of the present invention to provide a solar water heater that can accurately determine the temperature of the heat medium and can periodically check the circulation state of the heat medium without depending on the amount of solar radiation.

The present invention includes a solar heat collector that heats a heat medium using solar heat,
A hot water storage tank for storing hot water by exchanging heat between the supplied water and a heat medium heated by the solar heat collector;
A heat medium circulation conduit for circulating the heat medium between the solar heat collector and the hot water storage tank;
A circulation pump that is provided in the heat medium circulation pipe, circulates the heat medium, and a heat medium temperature detection unit that detects the temperature of the heat medium;
An auxiliary heat source machine for heating hot water discharged from the hot water storage tank and an auxiliary heat medium;
An auxiliary heat medium circulation pipe that extends from the auxiliary heat source machine and circulates an auxiliary heat medium heated by the auxiliary heat source machine;
A control unit for performing a circulating state inspection operation of the heat medium in the heat medium circulation pipe,
In performing the circulating state inspection operation of the heating medium, the control unit,
Raise the temperature of the heat medium in the heat medium circulation line with the auxiliary heat medium heated by operating the auxiliary heat source machine,
It is a solar water heater which judges whether the temperature change of the heat medium of the said heat-medium circulation pipe line detected by the said heat-medium temperature detection part becomes more than predetermined temperature.

  According to the solar water heater, the heat in the heat medium circulation pipe connecting the solar heat collector and the hot water storage tank is circulated by circulating the auxiliary heat medium heated by the auxiliary heat source machine in the auxiliary heat medium circulation pipe. The temperature of the medium can be raised. The solar heat collector has a low heat collection energy, and therefore the temperature change of the heat medium is small in the heating by the solar heat collector, whereas the auxiliary heat source machine can heat the auxiliary heat medium to an arbitrary temperature. Therefore, by heating the heating medium in the heating medium circulation pipe with the auxiliary heating medium, the temperature change of the heating medium can be increased, and thereby the detection error can be reduced. In addition, since the auxiliary heat source machine can heat the auxiliary heat medium without depending on the amount of solar radiation, the solar heat water supply apparatus inspects the circulation state of the heat medium without being limited to the amount of solar radiation. be able to.

The solar water heater is
A first on-off valve that is provided in the heat medium circulation pipe and communicates / blocks the flow of the heat medium in the heat medium circulation pipe;
A bypass path that bypasses the heat medium circulation forward path and the heat medium circulation return path of the heat medium circulation pipe;
A second on-off valve that is provided in the bypass passage and communicates / blocks the flow of the heat medium in the bypass passage;
Provided adjacent to the bypass path, heat exchange between the heat medium in the heat medium circulation pipe and the auxiliary heat medium circulated from the auxiliary heat source machine through the auxiliary heat medium circulation pipe, A liquid-to-heat exchange section for heating the heat medium,
In performing the circulating state inspection operation of the heating medium, the control unit,
Closing the first on-off valve and opening the second on-off valve so that the heat medium does not flow through the solar heat collector but flows through the bypass path;
The liquid heat exchanger may be heated with the heated auxiliary heat medium by operating the auxiliary heat source unit, and the temperature of the heat medium in the heat medium circulation pipe may be increased.

  The solar water heater includes a bypass path that bypasses the heat medium circulation forward path and the heat medium circulation return path of the heat medium circulation pipe, a first on-off valve in the heat medium circulation pipe, and a second on-off valve in the bypass path. And when performing the circulating state inspection operation of the heat medium, the control unit closes the first on-off valve so that the heat medium does not flow through the solar heat collector but flows through the bypass path, Since the second on-off valve is opened, the auxiliary heat medium heated by the liquid heat exchanger and the heat medium are heat-exchanged without circulating the heat medium heated by the auxiliary heat medium to the solar heat collector. As a result, the temperature of the heating medium can be raised. For this reason, the heat radiation from the solar heat collector due to the circulation of the high-temperature heat medium can be prevented, and the temperature drop of the heat medium by the solar heat collector can be prevented. As a result, since the temperature of the heat medium is not affected by the heat radiation from the solar heat collector, the temperature of the heat medium can be efficiently raised by the auxiliary heat medium, and the circulation state of the heat medium can be checked more accurately. Can do.

In the above solar water heater,
The solar heat collector further includes a solar power generation unit,
The circulating pump can be driven by any of the electric power from the solar power generation unit and the commercial power source,
In performing the circulating state inspection operation of the heating medium, the control unit,
The driving source of the circulation pump may be switched from electric power from the solar power generation unit to electric power from the commercial power source.

  If the circulation pump is driven by electric power from a solar power generation unit included in the solar heat collector, energy saving can be achieved during use of the solar water heater. If the amount of solar radiation is insufficient at night or in the rain, the power generated by the solar power generation unit becomes low. As a result, the drive of the circulation pump becomes unstable, and the circulation of the heat medium in the heat medium circulation pipe However, according to the solar water heater, in the circulating state inspection operation of the heating medium, it is circulated with power from a commercial power source that can supply stable power. Since the pump is driven, the heat medium can be stably circulated in the heat medium circulation pipe, and thereby, the circulation state of the heat medium can be more accurately inspected.

  And according to the said solar thermal water heater, since the circulation state of a heating medium can be test | inspected without being influenced by the amount of solar radiation, the circulating state inspection operation of a heating medium can be performed regularly.

  As described above, according to the present invention, it is possible to accurately determine the circulation state of the heat medium in the heat medium circulation pipe that circulates the heat medium between the solar heat collector and the hot water storage tank, and also depends on the amount of solar radiation. Therefore, it is possible to provide a solar water heater that can periodically inspect the circulation state of the heat medium.

FIG. 1 is a schematic configuration diagram showing an example of a solar hot water supply apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart showing an example of a control operation in the case of performing a circulating state inspection operation of the heat medium in the solar water heating apparatus according to the embodiment of the present invention.

Hereinafter, the solar water heating apparatus of the present embodiment will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an example of a solar hot water supply apparatus according to an embodiment of the present invention. A solar water heater of the present embodiment includes a solar heat collector 1, a hot water storage tank 2, an auxiliary heat source unit 3, an operation of the solar water heater and a remote controller 4 for setting the hot water temperature, and a hot water storage operation and a hot water supply operation of the solar water heater. And a control unit C for controlling the circulating state inspection operation of the heat medium and the like.

  The solar heat collector 1 is installed vertically on a veranda of an apartment house or installed on the roof of a building, etc., and includes a panel-shaped heat collecting plate (not shown) and a plurality of solar cells as solar power generation units. The solar cell panel 1a is composed of a power generation heat collecting unit in which the solar cell panels 1a are laminated and integrated, and has an internal flow path for circulating a heat medium therein. This internal flow path constitutes a part of the heat medium circulation conduit 7. The solar cell panel 1a disposed in the solar heat collector 1 is connected to the control unit C by electric wiring, and the power during power generation is always applied to the control unit C.

  The hot water storage tank 2 is a tank made of metal (for example, stainless steel) excellent in corrosion resistance, has a heat insulating material on the outer peripheral portion, and has a water supply port connected to a water supply pipe 5 for supplying water at the lower portion. The hot water storage tank 2 has a hot water outlet connected to a hot water discharge pipe 6, and four hot water storage tank thermistors 20 a, 20 b, 20 c, and 20 d are used as temperature detection means for detecting the temperature of hot water in the hot water storage tank 2. I have. The detection signals of the four hot water storage tank thermistors 20a, 20b, 20c, and 20d are output to the control unit C, and the detected temperatures are used for heating the water in the hot water storage tank 2, controlling the hot water temperature, calculating the heat storage amount, and the like. Is done.

  In the water supply pipe 5, a water supply source valve 51, a pressure reducing valve 52, an incoming water temperature thermistor 53 that detects the water supply temperature, a check valve 54, and a drain valve 55 are arranged in this order from the upstream side. The pressure reducing valve 52 is a valve that adjusts the water supply pressure to the hot water storage tank 2, and when the hot water in the hot water storage tank 2 decreases, the pressure on the downstream side of the pressure reducing valve 52 decreases, and the pressure in the hot water storage tank 2 accordingly. Therefore, water is supplied to the hot water storage tank 2.

  The hot water discharge pipe 6 is connected to a mixing valve M connected to a water supply branch pipe 9 branched from the water supply pipe 5. The hot water discharge pipe 6 includes a hot water temperature thermistor 61 that detects the temperature of hot water discharged from the hot water storage tank 2 in order from the upstream side between the hot water outlet of the hot water storage tank 2 and the mixing valve M, and the pressure in the hot water storage tank 2. A pressure relief valve 62 and a solenoid valve 63 are provided for discharging hot water when the pressure exceeds a predetermined pressure.

  The solar heat collector 1 and the hot water storage tank 2 are connected by a heat medium circulation pipe 7. The heat medium circulation pipe 7 is provided between the heat medium circulation forward path 7a for sending the heat medium heated by the solar heat collector 1 to the hot water storage tank 2, and the water supplied in the hot water storage tank 2 and the heated heat medium. The heat exchanging section 7b for exchanging heat and the heat medium circulation return path 7c for returning the heat medium cooled by the heat exchange to the solar heat collector 1 are connected to each other. The heat exchanging portion 7 b is configured by a pipe bent in a U shape or the like below the hot water storage tank 2. Further, the heat medium circulation outward path 7 a and the heat medium circulation return path 7 c outside the hot water storage tank 2 are communicated by a bypass path 14. As the heat medium, a conventionally known antifreeze containing propylene glycol or the like is used.

  In the heating medium circulation return path 7c of the heating medium circulation pipe 7, an open system cistern 8 for storing the heating medium, a circulation pump P, and a heating medium temperature detection unit for detecting the heating medium temperature are sequentially arranged from the upstream side. As shown, a heat medium thermistor 71 and a first thermal valve (first on-off valve) 72 are provided. The first thermal valve (first on-off valve) 72 is disposed closer to the solar heat collector 1 than the connection between the heat medium circulation return path 7c and the bypass path 14, and the heat medium circulation state inspection operation is performed. The on-off valve is normally open except during operation in which the heat medium in the heat medium circulation pipe is heated by the auxiliary heat medium (for example, hot water storage operation or hot water supply operation), and according to a signal from the control unit C, It is opened and closed, whereby the flow of the heat medium to the solar heat collector 1 is communicated / blocked. The first thermal valve (first on-off valve) 72 may be provided closer to the solar heat collector 1 than the connection with the bypass path 14 of the heating medium circulation path 7a, or the heating medium circulation path 7a, You may provide in both of the heat-medium circulation return paths 7c. The heat medium thermistor 71 is disposed closer to the hot water storage tank 2 than the connection portion between the heat medium circulation return path 7 c and the bypass path 14. The heat medium thermistor may also be provided in the heat medium circulation outward path 7a. The detection signal of the heat medium thermistor 71 is output to the control unit C.

  The bypass passage 14 is provided with a second thermal valve (second on-off valve) 142 that communicates / blocks the flow of the heating medium in the bypass passage 14 during the circulation state inspection operation of the heating medium. Is opened and closed in response to a signal from the heating medium, whereby the flow of the heat medium is communicated / blocked. The second thermal valve (second on-off valve) 142 is an on-off valve that is normally closed except during an operation in which the heat medium in the heat medium circulation pipe is heated by an auxiliary heat medium in a circulation state inspection operation or the like. In addition, a liquid-to-liquid heat exchanging portion 141 connected to the auxiliary heat source device 3 via the auxiliary heat medium circulation conduit 15 is disposed adjacent to the bypass passage 14. As the structure of the liquid-liquid heat exchanging unit 141, for example, a double pipe structure in which a pipe constituting the auxiliary heat medium circulation pipe 15 is provided so as to cover the circumference of the pipe constituting the bypass path 14, or through a partition wall. A structure in which the bypass passage 14 is connected to one chamber and the auxiliary heat medium circulation conduit 15 is connected to the other chamber can be employed.

  In the cistern 8, a high water level switch 81 for detecting the high water level of the heat medium, a low water level switch 82 for detecting the low water level of the heat medium, and a water level switch 83 for preventing the circulating pump P from idling are arranged. It is installed. In addition, an overflow pipe 84 for discharging the heat medium to the outside of the cis turn 8 when the heat medium overflows is disposed above the cis turn 8. The high water level switch 81 and the low water level switch 82 output a water level detection signal to the control unit C when touching the heat medium. Based on these water level detection signals, the control unit C determines whether the water level of the heat medium in the cistern 8 exceeds the high water level, is between the high water level and the low water level, or is lower than the low water level. To do.

  The circulation pump P is driven by electric energy when the power generation energy from the solar cell panel 1a disposed in the solar heat collector 1 is equal to or higher than a predetermined power during hot water storage operation or hot water supply operation. When the amount of solar radiation is insufficient at night or in rainy weather and the generated energy is less than a predetermined power, it is applied via a control board 33 connected to a power supply unit (not shown) that is a commercial power source. It is driven by electric power from the control unit C. In the circulating state inspection operation of the heat medium, the circulation pump P is driven by the electric power from the power supply unit. In this way, in the circulating state inspection operation of the heating medium, by driving the circulation pump P using electric power from a commercial power source, the heating medium can be stably stabilized in the heating medium circulation line 7 without depending on the amount of solar radiation. It can be circulated with.

  When hot water storage operation is performed in the solar water heater of the present embodiment, if solar radiation is radiated to the solar heat collector 1 and the power generation energy of the solar cell panel 1a applied to the control unit C is equal to or higher than a predetermined power, control is performed. The part C drives the circulation pump P with the electric power. Thereby, the heated heat medium is sent to the hot water storage tank 2, the water supplied into the hot water storage tank 2 is heated, and hot water is stored. In the hot water storage operation, the electromagnetic valve 63 provided in the hot water discharge pipe 6 is closed so that hot water is not discharged from the hot water storage tank 2.

  The mixing valve M disposed between the hot water storage tank 2 and the auxiliary heat source unit 3 connects the hot water discharged from the hot water storage tank 2 and the water supply branch pipe 9 according to the temperature of the hot water discharged from the hot water storage tank 2. It is a valve that mixes the water supplied from the water supply pipe 5 through the valve, and its opening degree is adjusted according to the signal from the control unit C.

  The auxiliary heat source unit 3 is disposed on the downstream side of the hot water storage tank 2, and includes a hot water supply heating unit 31, an auxiliary heat medium heating unit 32, and a control board 33 that controls operations of the heating units 31 and 32. And. Each of the heating units 31 and 32 includes a hot water supply heat exchanger 311 and a hot water supply gas burner 312, an auxiliary heat medium heating heat exchanger 321, and an auxiliary heat medium heating gas burner 322.

  The hot water supply heat exchanger 311 is connected to the mixing valve M by the mixing pipe 10, and the mixed hot water mixed by the mixing valve M flows in. In the mixing pipe 10, a water amount sensor 11, a mixing thermistor 12, and a high cut thermistor 13 are arranged in this order from the upstream side. The water amount sensor 11 detects the flow rate of the mixed hot water flowing through the mixing pipe 10, and the detection signal is output to the control unit C. The mixing thermistor 12 and the high-cut thermistor 13 detect the temperature of the mixed hot water flowing out from the mixing valve M, and these detection signals are output to the control unit C. The mixed hot water heated by the hot water supply heat exchanger 311 is supplied from the hot water supply pipe L to a hot water outlet terminal such as a currant provided in a bathroom or kitchen.

  When the hot water supply operation is performed with the solar hot water supply apparatus of the present embodiment, when the hot water outlet terminal is opened, water is supplied from the water supply branch pipe 9 to the mixing pipe 10 through the mixing valve M. Then, when flowing water of a predetermined flow rate or more is detected by the water amount sensor 11, the control unit C opens the electromagnetic valve 63 provided in the tap water pipe 6. When the solenoid valve 63 is opened, hot water is discharged from the hot water storage tank 2 to the hot water discharge pipe 6, and the hot water temperature thermistor 61 detects the temperature of the hot water discharged and outputs the detected temperature to the control unit C. When the temperature of the hot water discharged from the hot water storage tank 2 is higher than the temperature required at the hot water terminal input to the control unit C by operating the hot water supply temperature setting switch of the remote controller 4, the control unit C controls the mixing valve. The opening of M is adjusted, hot water and water supplied from the water supply branch pipe 9 are mixed, and the hot water supply unit 31 is supplied with the mixed hot water at a predetermined temperature without operating the hot water supply heating unit 31. On the other hand, when the temperature of the hot water discharged from the hot water storage tank 2 is lower than the temperature required at the hot water terminal, the control unit C adjusts the opening of the mixing valve M to a predetermined ratio and operates the hot water supply heating unit 31. The hot water supply gas burner 312 is ignited. The hot water discharged from the hot water storage tank 2 is mixed with water by the mixing valve M and then heated by the heat exchanger 311 for hot water supply, and the mixed hot water at a predetermined temperature is supplied to the hot water terminal.

  The auxiliary heat medium heating heat exchanger 321 is connected to the liquid heat exchanger 141 provided in the bypass path 14 described above and the auxiliary heat medium circulation pipe 15 extending from the auxiliary heat source unit 3. The auxiliary heat medium circulation pipe 15 is connected to the auxiliary heat medium circulation forward path 15a for sending the auxiliary heat medium heated by the auxiliary heat medium heating heat exchanger 321 to the liquid-to-liquid heat exchanging unit 141 by the auxiliary heat medium circulation pump. The auxiliary heat medium circulating return path 15b returns the auxiliary heat medium cooled by the auxiliary heat medium to the auxiliary heat medium heating heat exchanger 321. The auxiliary heat medium circulation forward path 15a communicates / blocks the flow of the auxiliary heat medium. A thermal valve 151 is provided. The auxiliary heat medium circulation pump is driven by electric power from a commercial power source. As the auxiliary heat medium, hot water (which may contain an antifreeze liquid) heated by the heat exchanger 321 for heating the auxiliary heat medium can be used.

  The heating unit 32 for heating the auxiliary heat medium is normally used as a heating unit for heating the heating device W or the like. In the present embodiment, this auxiliary heat medium is used when performing the circulating state inspection operation of the heat medium. The heating unit 32 for heating the medium is operated to heat the auxiliary heat medium, and the temperature of the heat medium in the heat medium circulation pipe 7 is forcibly raised by the heated auxiliary heat medium. The auxiliary heat medium heating unit 32 has less heat collection energy collected by the solar heat collector 1, and the amount of solar radiation is insufficient, so that hot water of a predetermined temperature is not stored in the hot water storage tank 2. When the solar water heater is not used for a long time, the hot water in the hot water storage tank 2 is not replaced, and there is a possibility that various germs may propagate, so that the heating medium circulation line 7 is reheated and the hot water in the hot water storage tank 2 is reheated. You may use as a heating unit for raising temperature.

  The control unit C is configured mainly with a microcomputer, and includes a ROM in which an inspection operation program for executing a circulating state inspection operation of a heating medium (not shown) is stored, and an inspection detected by the heating medium thermistor 71. Storage unit for storing the temperature of the initial heat medium, comparison unit for comparing the temperature of the heat medium detected by the heat medium thermistor 71 within the inspection time and the initial temperature, and the heat medium within the inspection time compared by the comparison unit A determination unit for determining whether or not the temperature change is equal to or higher than a predetermined temperature, a notification unit for notifying the abnormality of the circulation state of the heating medium from the remote controller 4 when the temperature change is lower than the predetermined temperature, and an inspection time or heat A timer for measuring a predetermined periodic time for periodically performing the circulating state inspection operation of the medium is provided. In addition, the control unit C includes the solar heat collector 1, the control board 33 in the auxiliary heat source unit 3, the circulation pump P, the water amount sensor 11, and the respective thermistors 12, 13, 20a, 20b, 20c, 20d, 53, 61, 71, thermal valves 72, 142, 151, electromagnetic valve 63, mixing valve M, etc. are connected via remote control 4 and control board 33 in auxiliary heat source unit 3 arranged in a bathroom or kitchen. It is connected.

  Next, in the solar hot water supply apparatus of the present embodiment, a control operation for performing the heat medium circulation state inspection operation of the heat medium circulation pipe 7 will be specifically described with reference to the flowchart of FIG. In the present embodiment, this inspection operation program is set to be started every 720 hours.

  First, the control unit C determines whether or not a predetermined period of time has elapsed since the previous circulating state inspection operation of the heating medium (ST1).

  When the predetermined period of time has elapsed (YES in ST1), the storage unit stores the initial temperature of the heat medium detected by the heat medium thermistor 71 at the start of the inspection operation (ST2). Next, the control unit C operates the auxiliary heat medium heating unit 32 of the auxiliary heat source unit 3 to ignite the auxiliary heat medium heating gas burner 322 to start heating the auxiliary heat medium, and the auxiliary heat medium circulation pipe The thermal valve 151 of the passage 15 is opened (ST3). Thereby, the auxiliary heat medium heated by the auxiliary heat medium circulation line 15 is circulated.

  When heating of the auxiliary heat medium is started in the auxiliary heat source unit 3, the controller C closes the first thermal valve (first on-off valve) 72 and the second thermal valve (second on-off valve) 142. And the circulation path of the heat medium is switched so that the heat medium does not flow through the solar heat collector 1 but flows through the bypass 14 (ST4). Thereby, since a heat medium does not distribute | circulate the solar-heat collector 1 at the time of test | inspection driving | operation, even if it circulates a high-temperature heat medium, heat radiation does not arise from the solar-heat collector 1, and the amount of heat exchanged by the auxiliary heat medium Only by this, the temperature of the heating medium can be raised. Therefore, it is not necessary to consider the temperature drop of the heat medium by the solar heat collector 1 in measuring the temperature change of the heat medium. Furthermore, for the purpose of reducing false detection of temperature change, even if a high temperature auxiliary heat medium is used and the heat medium is heated to a high temperature, the heat medium is not circulated through the solar heat collector 1. Is not overheated. Moreover, the control part C switches the drive source of the circulation pump P from the electric power by the solar cell panel 1a to the electric power by a commercial power supply, and drives the circulation pump P (ST4). As a result, the circulation pump P can be driven at a stable drive speed.

  Next, the control unit C compares the initial temperature of the heat medium stored in the storage unit with the temperature of the heat medium detected by the heat medium thermistor 71 in the comparison unit, and determines the initial temperature of the heat medium in the determination unit. It is determined whether the temperature change from the temperature to the temperature of the heat medium detected by the heat medium thermistor 71 during the inspection operation is equal to or higher than a predetermined temperature (for example, 3 ° C.) (ST5). At this time, in consideration of the case where the circulation state of the heat medium during the inspection operation varies, it is further determined whether or not the temperature of the heat medium during the inspection operation continues for a certain time (for example, 1 second). Also good.

  When the temperature change of the heat medium detected by the heat medium thermistor 71 is equal to or higher than the predetermined temperature (YES in ST5), the control unit C determines that the circulation state of the heat medium is normal, and the first heat valve (first heat valve) 1 on-off valve) 72, and the second thermal valve (second on-off valve) 142 is closed so that the heat medium does not flow through the bypass 14 but flows through the solar heat collector 1. While switching the circulation path of the heat medium, the drive source of the circulation pump P is switched from the power from the commercial power source to the power from the solar cell panel 1a (ST6). Then, the operation of the auxiliary heat source unit 3 is terminated (ST7), and the timer is reset to perform the next periodic inspection operation (ST8).

  On the other hand, when the difference between the initial temperature of the heat medium and the temperature of the heat medium detected by the heat medium thermistor 71 during the inspection operation is small and the temperature change of the heat medium is less than a predetermined temperature (NO in ST5), control is performed. Part C further determines whether or not a predetermined inspection time (for example, 3 minutes) has elapsed (ST9). If the temperature change of the heat medium is less than the predetermined temperature even after the inspection time has elapsed (YES in ST9), the determination unit determines whether the heat medium in the heat medium circulation pipe 7 has fallen due to a failure of the circulation pump P or the like. It is determined that the circulation is abnormal, and an error signal is transmitted from the error notification unit to the remote controller 4 to notify the abnormality from the speaker or display unit of the remote controller 4 (ST10).

  According to the solar water heater, the heat medium circulating through the heat medium circulation pipe 7 can be heated with the auxiliary heat medium that can be heated to an arbitrary temperature by the auxiliary heat source device 3 during the circulation state inspection operation of the heat medium. Thus, the heating medium can be heated to a higher temperature than when the heating medium is heated by the solar heat collector 1 having low heat collecting energy. Thereby, since the temperature change of a heating medium can be enlarged, the erroneous detection of the temperature difference of a heating medium can be reduced, and the circulation state of a heating medium can be judged correctly.

  Moreover, in the circulating state inspection operation of the heat medium, the temperature of the heat medium in the heat medium circulation pipe 7 can be raised by the auxiliary heat medium heated by the auxiliary heat source unit 3, which is influenced by the amount of solar radiation. The inspection operation can be performed periodically without any problems.

  In the above-described embodiment, the solar heat water heater having a gas water heater has been described as an example of the auxiliary heat source unit 3. However, the auxiliary heat source unit 3 of the present embodiment is not limited to this. For example, a conventionally known auxiliary heat source device such as a heat pump may be used.

1 Solar collector 1a Solar panel (solar power generation unit)
2 Hot-water storage tank 3 Auxiliary heat source machine 7 Heat medium circulation pipe 7a Heat medium circulation forward path 7b Heat exchange part 7c Heat medium circulation backward path 14 Bypass path 15 Auxiliary heat medium circulation pipe 15a Auxiliary heat medium circulation forward path 15b Auxiliary heat medium circulation backward path 71 Heat medium thermistor (heat medium temperature detection part)
72 First thermal valve (first on-off valve)
141 Liquid heat exchanger 142 Second thermal valve (second on-off valve)
C Control part P Circulation pump

Claims (4)

A solar collector that uses solar heat to heat the heating medium;
A hot water storage tank for storing hot water by exchanging heat between the supplied water and a heat medium heated by the solar heat collector;
A heat medium circulation conduit for circulating the heat medium between the solar heat collector and the hot water storage tank;
A circulation pump that is provided in the heat medium circulation pipe, circulates the heat medium, and a heat medium temperature detection unit that detects the temperature of the heat medium;
An auxiliary heat source machine for heating hot water discharged from the hot water storage tank and an auxiliary heat medium;
An auxiliary heat medium circulation pipe that extends from the auxiliary heat source machine and circulates an auxiliary heat medium heated by the auxiliary heat source machine;
A control unit for performing a circulating state inspection operation of the heat medium in the heat medium circulation pipe,
In performing the circulating state inspection operation of the heating medium, the control unit,
Raise the temperature of the heat medium in the heat medium circulation line with the auxiliary heat medium heated by operating the auxiliary heat source machine,
The solar water heater which judges whether the temperature change of the heat medium of the said heat-medium circulation pipe line detected by the said heat-medium temperature detection part becomes more than predetermined temperature. A first on-off valve that is provided in the heat medium circulation pipe and communicates / blocks the flow of the heat medium in the heat medium circulation pipe;
A bypass path that bypasses the heat medium circulation forward path and the heat medium circulation return path of the heat medium circulation pipe;
A second on-off valve that is provided in the bypass passage and communicates / blocks the flow of the heat medium in the bypass passage;
Provided adjacent to the bypass path, heat exchange between the heat medium in the heat medium circulation pipe and the auxiliary heat medium circulated from the auxiliary heat source machine through the auxiliary heat medium circulation pipe, A liquid-to-heat exchange section for heating the heat medium,
In performing the circulating state inspection operation of the heating medium, the control unit,
Closing the first on-off valve and opening the second on-off valve so that the heat medium does not flow through the solar heat collector but flows through the bypass path;
2. The solar water heating apparatus according to claim 1, wherein the liquid heat exchanger is heated by the heated auxiliary heat medium by operating the auxiliary heat source unit to raise the temperature of the heat medium in the heat medium circulation pipe. . The solar heat collector further includes a solar power generation unit,
The circulating pump can be driven by any of the electric power from the solar power generation unit and the commercial power source,
In performing the circulating state inspection operation of the heating medium, the control unit,
The solar thermal water heater according to claim 1 or 2, wherein a driving source of the circulation pump is switched from electric power by the solar power generation unit to electric power by the commercial power source. The solar control hot water supply apparatus according to any one of claims 1 to 3, wherein the control unit periodically performs a circulating state inspection operation of the heat medium.

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