JP6026154B2 - Solar heat utilization system and pump control method thereof - Google Patents

Description

  The present invention relates to a solar heat utilization system and a pump control method thereof.

  Conventionally, there is a solar heat utilization system that supplies a heat medium to a heat collector, heats cold water using a heat medium heated by receiving sunlight, and supplies hot water obtained by heating to the home or the like. It has been proposed (see Patent Documents 1 and 2).

  A solar heat utilization system has also been proposed in which a heat medium is circulated by driving a pump. In this solar heat utilization system, the pump operates when the heat medium temperature is lower than X ° C. (X is an arbitrary number), circulates the heat medium, and stops when the heat medium temperature exceeds X ° C. It has become. Thereby, the situation where a hot heat medium circulates and the electronic components in a pump, etc. are damaged can be prevented (refer to patent documents 3).

JP-A-63-213763 JP-A 63-207951 JP-A-60-207855

  However, in such a solar heat utilization system, the pump is stopped depending on whether or not the temperature of the heat medium is equal to or higher than X ° C. Therefore, when the ambient temperature is extremely low, the electronic components are more than usual due to the ambient atmosphere. Therefore, it is difficult to say that the control is appropriate. When the electronic parts are cooled more than usual, the pump is stopped regardless of the state in which the higher-temperature heat medium can be circulated, which is efficient in terms of collecting heat. It will cause a decline.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a solar heat utilization system and a pump control method thereof capable of improving the heat extraction efficiency. It is in.

  The solar heat utilization system of the present invention includes a heat collector that heats a heat medium by receiving sunlight, a heat exchanger that heats cold water using the heat medium heated by the heat collector, and heat exchange. A solar heat utilization system comprising a pump that circulates the heat medium from the heat exchanger to the heat exchanger again, and a heat medium temperature detection unit that detects the temperature of the heat medium, and a heat medium temperature detection unit. Based on the detected temperature of the heat medium, a control unit that stops the pump and an atmospheric temperature detection unit that detects the atmospheric temperature are provided. The control unit lowers the atmospheric temperature detected by the atmospheric temperature detection unit. According to the invention, the stop temperature for stopping the pump is increased.

  According to the solar heat utilization system of the present invention, as the ambient temperature becomes lower, the stop temperature for stopping the pump is increased. Since the medium can be circulated and heat exchange can be performed by the heat medium, the heat collecting efficiency is increased. Accordingly, the heat extraction efficiency can be improved.

  Moreover, in the solar heat utilization system of this invention, the cold water piping which introduces the cold water heated with a heat exchanger, the hot water supply pipe which supplies the hot water heated with the heat exchanger to a household side, cold water piping, and hot water And a heater provided on at least one of the supply pipes, and the controller preferably controls the heater on and off based on the ambient temperature detected by the ambient temperature detector.

  According to this solar heat utilization system, since the heater is turned on / off based on the ambient temperature detected by the ambient temperature detector, the heater is also turned on / off using a sensor for turning on / off the pump. To simplify the configuration.

  Further, the pump control method of the solar heat utilization system of the present invention includes a heat collector that heats a heat medium by receiving sunlight, and heat that heats cold water using the heat medium heated by the heat collector. A heat medium temperature for detecting a temperature of a heat medium, the pump control method of a solar heat utilization system comprising an exchanger and a pump for circulating the heat medium from the heat exchanger to the heat exchanger again through the heat collector A detection step; a control step for stopping the pump based on the temperature of the heat medium detected in the heat medium temperature detection step; and an atmosphere temperature detection step for detecting the ambient temperature. The stop temperature at which the pump is stopped is increased as the atmospheric temperature detected in the detection step decreases.

  According to the pump control method of this solar heat utilization system, in order to increase the stop temperature for stopping the pump as the ambient temperature decreases, the temperature is higher in an environment where electronic components are cooled by the ambient temperature such as in the cold season. Since the heat medium can be circulated and heat exchange can be performed with this heat medium, the heat collecting efficiency is increased. Accordingly, the heat extraction efficiency can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the solar heat utilization system which can improve the extraction | collection efficiency of calorie | heat amount, and its pump control method can be provided.

1 is a schematic configuration diagram of a solar heat utilization system according to an embodiment of the present invention. It is a graph which shows the relationship between atmospheric temperature and stop temperature. It is a basic flowchart which shows the pump control method of the solar heat utilization system which concerns on this embodiment. It is a sub-flowchart which shows the pump control method of the solar heat utilization system which concerns on this embodiment. It is a schematic block diagram of the solar heat utilization system which concerns on 2nd Embodiment. It is a flowchart which shows the heater control method of the solar-heat utilization system which concerns on 2nd Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a solar heat utilization system according to an embodiment of the present invention. As shown in FIG. 1, the solar heat utilization system 1 according to this embodiment obtains hot water using solar heat, and includes a heat collector 10, a hot water storage tank unit 20, and a pipe L that connects them. It has.

  The heat collector 10 heats the heat medium by receiving sunlight, and is installed at a position where it is easy to receive sunlight, such as on a roof.

  The hot water storage tank unit 20 heats the cold water using the heat medium heated by the heat collector 10 and sent through the pipe L, and supplies the hot water obtained by the heating to a home or the like. The hot water storage tank unit 20 stores hot water when hot water is not used at home or the like. The hot water storage tank unit 20 includes a cold water pipe 21, a can 22, a heat exchanger 23, a hot water pipe 24, a cistern 25, a pump P, and a control unit 26.

  The cold water pipe 21 is a pipe for supplying cold water into the can body 22. The can body 22 introduces cold water from the cold water pipe 21 and stores hot water obtained by heating. The heat exchanger 23 is provided in the can 22 and heats the cold water by performing heat exchange between the heat medium flowing through the pipe L and the cold water. The hot water pipe 24 is a pipe for supplying hot water obtained by heating the heat exchanger 23 to a home or the like.

  The cistern 25 is a device that accumulates the heat medium returning from the heat collector 10 and has a function of discharging the mixed air when it is mixed in the pipe L. Further, for example, when the circulation of the heat medium is stopped, the cistern 25 is heated and heated by the heat collector 10 to expand and evaporate, and the pressure in the pipe L is increased. It also has functions to prevent it.

  The pump P is provided on the pipe L, and circulates the heat medium from the heat exchanger 23 through the heat collector 10 to the heat exchanger 23 again by driving thereof. The control unit 26 performs valve opening / closing control of the hot water storage tank unit 20, on / off control of the pump P, and the like.

  Further, the solar heat utilization system 1 includes a high temperature sensor T1, a low temperature sensor T2, a heat medium thermistor (heat medium temperature detection unit) T3, and an atmosphere temperature sensor (atmosphere temperature detection unit) T4.

  The high temperature sensor T1 is provided in the heat collector 10 or in the vicinity of the outlet of the heat collector 10, and detects the temperature of the heat medium heated by the heat collector 10. The low temperature sensor T2 is installed on the lower outer wall of the can body 22 and detects the temperature of water (hot water during heating) in the vicinity of the heat exchanger 23.

  The heat medium thermistor T3 detects the temperature of the heat medium, and is provided on the downstream side of the pump P in this embodiment. For this reason, the heat medium thermistor T3 detects the temperature of the heat medium after the heat exchange sent from the pump P to the heat collector 10.

  The ambient temperature sensor T4 detects the ambient temperature in the hot water storage tank unit 20. In the present embodiment, the ambient temperature sensor T4 is provided in the vicinity of the pump P (particularly the electronic components of the pump P) and is configured to detect the ambient temperature around the pump P.

  Next, the outline of the pump control method of the solar heat utilization system 1 which concerns on this embodiment is demonstrated. First, it is assumed that the pump P is stopped. In this state, the control unit 26 detects the respective temperatures based on the signals from the high temperature sensor T1 and the low temperature sensor T2, and determines whether the temperature difference (T1-T2) is equal to or higher than A ° C. To do. When it is determined that the temperature difference (T1−T2) is equal to or higher than A ° C., the control unit 26 turns on the pump P.

  Even during operation of the pump P, the control unit 26 detects the respective temperatures based on signals from the high temperature sensor T1 and the low temperature sensor T2. And the control part 26 judges whether these temperature differences (T1-T2) are below B degreeC. When it is determined that the temperature difference (T1−T2) is equal to or lower than B ° C., the control unit 26 turns off the pump P.

  Furthermore, the control unit 26 forcibly turns off the pump P according to the heat medium temperature so that the pump P does not break down due to the high temperature heat medium. Here, in the conventional solar heat utilization system, for example, when the heat medium temperature is detected based on a signal from the heat medium thermistor and it is determined that this temperature is equal to or higher than X ° C., the pump is forcibly turned off, The pump is kept off until the time is reached.

  However, since the pump is stopped depending on whether the heat medium temperature is equal to or higher than X ° C., consideration is given to the case where the electronic components of the pump P are cooled more than usual by the ambient atmosphere, such as when the ambient temperature is low. It is hard to say that it is appropriate control. When the electronic parts are cooled more than usual, the pump is stopped regardless of the state in which the higher-temperature heat medium can be circulated, which is efficient in terms of collecting heat. It will cause a decline.

  Therefore, the solar heat utilization system 1 according to the present embodiment increases the stop temperature at which the pump P is stopped as the ambient temperature detected by the ambient temperature sensor T4 decreases. That is, the control unit 26 does not uniformly determine whether the heat medium temperature is equal to or higher than X ° C., but determines whether the heat medium temperature is equal to or higher than X + Δt ° C. as the ambient temperature becomes lower. When the temperature is equal to or higher than X + Δt ° C., the pump P is stopped. Here, Δt is a temperature increase corresponding to the ambient temperature, and is a positive value.

FIG. 2 is a chart showing the relationship between the ambient temperature and the stop temperature. In FIG. 2, Y ₁ <Y ₂ <Y ₃ <Y ₄ <Y ₅ and X ₁ <X ₂ <X ₃ <X ₄ <X ₅ .

As shown in FIG. 2, when the atmospheric temperature is lower than Y ₁ ° C, the stop temperature of the pump P is set to X ₅ ° C. Also, if the ambient temperature is less than Y ₁ ° C. or more Y ₂ ° C., stop temperature of the pump P is the X ₄ ° C.. Similarly, when the ambient temperature is Y ₂ ° C or more and less than Y ₃ ° C, the stop temperature of the pump P is set to X ₃ ° C, and when the ambient temperature is Y ₃ ° C or more and less than Y ₄ ° C, Is X ₂ ° C. When the atmospheric temperature is Y ₄ ° C or higher and lower than Y ₅ ° C, the stop temperature of the pump P is set to X ₁ ° C.

  Thus, in the solar heat utilization system 1 according to the present embodiment, in order to increase the stop temperature at which the pump P is stopped as the ambient temperature becomes lower, in an environment where electronic components are cooled by the ambient temperature such as in the cold season, A higher temperature heat medium is circulated. Then, heat extraction efficiency is increased by performing heat exchange with a heat medium having a higher temperature.

  Next, detailed operation | movement of the solar-heat utilization system 1 which concerns on this embodiment is demonstrated with reference to a flowchart. FIG. 3 is a basic flowchart showing a pump control method of the solar heat utilization system 1 according to the present embodiment. First, in FIG. 3, it is assumed that the pump P is stopped. In this state, the control unit 26 detects the respective temperatures from the signals of the high temperature sensor T1 and the low temperature sensor T2 (S1).

  Next, the control unit 26 determines whether or not these temperature differences (T1−T2) are equal to or higher than A ° C. (S2). When it is determined that the temperature difference (T1−T2) is not equal to or higher than A ° C. (S2: NO), the process proceeds to step S1.

  When it is determined that the temperature difference (T1−T2) is equal to or higher than A ° C. (S2: YES), the control unit 26 turns on the pump P (S3). Then, the control part 26 detects each temperature again from the signal of the high temperature sensor T1 and the low temperature sensor T2 (S4). Next, the control unit 26 determines whether or not these temperature differences (T1−T2) are equal to or lower than B ° C. (S5). When it is determined that the temperature difference (T1−T2) is equal to or lower than B ° C. (S5: YES), the control unit 26 turns off the pump P (S6). Then, the process shown in FIG. 3 ends.

  On the other hand, when it is determined that the temperature difference (T1−T2) is not equal to or lower than B ° C. (S5: NO), the process proceeds to step S4.

  FIG. 4 is a sub-flowchart showing a pump control method of the solar heat utilization system 1 according to the present embodiment. The solar-heat utilization system 1 which concerns on this embodiment is performing the characteristic process shown in FIG. The process shown in FIG. 4 is executed when the pump P is operating.

  As shown in FIG. 4, first, the control unit 26 detects the ambient temperature from the signal of the ambient temperature sensor T4 (S11). Next, the control unit 26 determines the stop temperature of the pump P from the ambient temperature detected in step S11 (S12). At this time, the control unit 26 determines the stop temperature from data as shown in FIG. The method for determining the stop temperature is not limited to the above, and for example, a predetermined arithmetic expression having the ambient temperature as a variable may be used.

  Next, the control unit 26 detects the heat medium temperature from the signal of the heat medium thermistor T3 (S13). And the control part 26 judges whether the heat-medium temperature detected in step S13 is more than the stop temperature determined in step S12 (S14). When it is determined that the temperature is equal to or higher than the stop temperature (S14: YES), the control unit 26 forcibly turns off the pump P (S15), and maintains the pump P in an off state until a predetermined time is reached. . Then, the process shown in FIG. 4 ends.

  On the other hand, if it is determined that the temperature is not equal to or higher than the stop temperature (S14: NO), the control unit 26 ends the process shown in FIG.

  Thus, according to the solar heat utilization system 1 and the pump control method according to the present embodiment, as the ambient temperature becomes lower, the stop temperature for stopping the pump P is increased. In a cooled environment, a heat medium having a higher temperature can be circulated, and heat exchange can be performed by this heat medium, so that the heat extraction efficiency is increased. Accordingly, the heat extraction efficiency can be improved.

  Next, a second embodiment of the present invention will be described. The solar heat utilization system according to the second embodiment is the same as that of the first embodiment, but the configuration and processing contents are partially different. Hereinafter, differences from the first embodiment will be described.

FIG. 5 is a schematic configuration diagram of the solar heat utilization system 2 according to the second embodiment. As shown in FIG. 5, in the solar heat utilization system 2 according to the second embodiment, the first heater 27 is attached to the cold water pipe 21 and the second heater 28 is attached to the hot water pipe 24. . These heaters 27 and 28 are for heating the pipes 21 and 24 so as not to be damaged by cooling in a cold season or the like. For example, the heaters 27 and 28 are turned on when Z ₁ ° C. or lower and turned off when Z ₂ ° C. or higher. ing.

  Here, conventionally, in order to prevent the pipes 21 and 24 from being damaged, a bimetal switch is provided along with the heaters 27 and 28, and the heaters 27 and 28 are turned on and off according to the detected temperature of the bimetal switch.

However, the solar heat utilization system 2 according to the second embodiment includes the ambient temperature sensor T4 as in the first embodiment. In the second embodiment, the control unit 26 detects the ambient temperature from the signal from the ambient temperature sensor T4. When the ambient temperature is equal to or lower than Z ₁ (Z ₁ is an arbitrary number) ° C., the heaters 27 and 28 are turned on. When the ambient temperature becomes Z ₂ (Z ₂ is an arbitrary number exceeding Z ₁ ) ° C. or higher, the heaters 27 and 28 are turned off.

  This eliminates the need for a bimetal switch as in the prior art, and simplifies the configuration.

FIG. 6 is a flowchart showing a heater control method of the solar heat utilization system 2 according to the second embodiment. First, as shown in FIG. 6, the control unit 26 detects the ambient temperature from the signal of the ambient temperature sensor T4 (S21). Next, the control unit 26 determines whether or not the ambient temperature detected in step S21 is equal to or lower than Z ₁ ° C (S22).

When it is determined that the temperature is not lower than Z ₁ ° C (S22: NO), the process proceeds to step S21. On the other hand, when it is determined that the temperature is equal to or lower than Z ₁ ° C (S22: YES), the control unit 26 turns on the heaters 27 and 28 (S23).

Thereafter, the control unit 26 detects the ambient temperature again from the signal of the ambient temperature sensor T4 (S24). Next, the control unit 26 determines whether or not the ambient temperature detected in step S21 is equal to or higher than Z ₂ ° C (S25).

When it is determined that the temperature is not higher than Z ₂ ° C (S25: NO), the process proceeds to step S24. On the other hand, when it is determined that the temperature is equal to or higher than Z ₂ ° C (S25: YES), the control unit 26 turns off the heaters 27 and 28 (S23). Then, the process of FIG. 6 ends.

  In addition, although illustration is abbreviate | omitted in 2nd Embodiment, the solar-heat utilization system 2 which concerns on 2nd Embodiment also performs also about the process shown in FIG.3 and FIG.4.

  Thus, according to the solar-heat utilization system 2 and pump control method which concern on 2nd Embodiment, the extraction | collection efficiency of calorie | heat amount can be improved similarly to 1st Embodiment.

  Further, since the heaters 27 and 28 are controlled to be turned on and off based on the atmospheric temperature detected by the atmospheric temperature sensor T4, the heaters 27 and 28 are also turned on and off using a sensor for turning on and off the pump P. It can be shared to simplify the configuration.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention.

  For example, in the present embodiment, the ambient temperature sensor T4 is provided in the vicinity of the electronic component of the pump P, but is not limited thereto, and may be provided in other locations as long as it is within the unit 20.

  The heat medium thermistor T3 is provided on the downstream side of the pump P, but is not limited thereto, and may be provided on the upstream side of the pump P, or provided on the upstream side of the heat exchanger 23. Also good. Note that it is desirable that the heat medium thermistor T3 is provided closer to the pump P from the viewpoint of preventing the electronic components of the pump P from malfunctioning.

DESCRIPTION OF SYMBOLS 1 ... Solar heat utilization system 10 ... Collector 20 ... Hot water storage tank unit 21 ... Cold water piping 22 ... Can body 23 ... Heat exchanger 24 ... Hot water piping 25 ... Systern 26 ... Control part 27, 28 ... Heater L ... Piping P ... Pump T1 ... High temperature sensor T2 ... Low temperature sensor T3 ... Heat medium thermistor (heat medium temperature detector)
T4 ... Atmosphere temperature sensor (atmosphere temperature detector)

Claims (3)

A heat collector that heats the heat medium by receiving sunlight, a heat exchanger that heats cold water using the heat medium heated by the heat collector, and the heat collector from the heat exchanger A solar heat utilization system provided with a pump that circulates the heat medium again in the heat exchanger via
A heat medium temperature detector for detecting the temperature of the heat medium;
Based on the temperature of the heat medium detected by the heat medium temperature detection unit, a control unit that stops the pump;
An ambient temperature detector for detecting the ambient temperature,
The said control part raises the stop temperature which stops the said pump as the atmospheric temperature detected by the said atmospheric temperature detection part becomes low. The solar-heat utilization system characterized by the above-mentioned. Cold water piping for introducing cold water heated in the heat exchanger;
A hot water supply pipe for supplying hot water heated by the heat exchanger to the household side;
A heater provided in at least one of the cold water pipe and the hot water supply pipe,
The solar heat utilization system according to claim 1, wherein the control unit performs on / off control of the heater based on the ambient temperature detected by the ambient temperature detection unit. A heat collector that heats the heat medium by receiving sunlight, a heat exchanger that heats cold water using the heat medium heated by the heat collector, and the heat collector from the heat exchanger And a pump for circulating a heat medium again in the heat exchanger, and a solar heat utilization system pump control method comprising:
A heat medium temperature detecting step for detecting the temperature of the heat medium;
A control step of stopping the pump based on the temperature of the heat medium detected in the heat medium temperature detection step;
An ambient temperature detecting step for detecting the ambient temperature,
In the said control process, the stop temperature which stops the said pump is raised as the atmospheric temperature detected in the said atmospheric temperature detection process becomes low. The pump control method of the solar heat utilization system characterized by the above-mentioned.

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