JP6721116B2 - Heat medium circulation system - Google Patents

Description

The present invention relates to a heat medium circulation system.

A heating system is known in which a liquid heat medium heated by a heat pump having an air heat exchanger for exchanging heat between a refrigerant and air and a compressor for compressing the refrigerant is circulated to a heating terminal. If the heating operation is performed when the outside air temperature is low, frost may adhere to the air heat exchanger. In this case, it is necessary to temporarily suspend the heating operation and perform the defrosting operation for removing frost.

The system disclosed in Patent Document 1 below is performed as follows. When the operation is restarted after the defrosting operation is completed, the upper limit value of the temperature of the hot water supplied to the floor heating equipment is set to 55°C, 50°C, 45°C, or the like. The time at the upper limit of 55° C. is 5 minutes, and the time at the upper limit of 50° C. is 5 minutes.

Japanese Unexamined Patent Publication No. 2006-046703

If the temperature of the heating medium supplied to the heating terminal becomes too high, comfort may be impaired. Therefore, it is possible to stop the heating operation when the supply temperature exceeds the predetermined temperature. However, if the frequency of starting and stopping the compressor is high, there is a possibility that energy may be lost and the life of the compressor may be shortened.

The present invention has been made to solve the above problems, and provides a heat medium circulation system capable of reducing the frequency of starting and stopping a compressor included in a heating unit that heats a heat medium. With the goal.

A heat medium circulation system of the present invention includes an air heat exchanger that exchanges heat between a refrigerant and air, a compressor that compresses a refrigerant, a heating unit that heats a liquid heat medium, and a heating terminal. A pump that circulates the heat medium in a circulation circuit that passes through the heating means and the heating means; a heating operation that is electrically connected to the heating means and the pump and that supplies the heat medium heated by the heating means to the heating terminal; Control means configured to perform a defrosting operation for melting the frost adhering to the exchanger, and means for detecting a supply temperature that is the temperature of the heat medium supplied from the heating means to the heating terminal, The control means stops the compressor when the supply temperature exceeds the first stop temperature in the heating operation after a predetermined time has elapsed from the switching time from the defrosting operation to the heating operation, and the predetermined time has elapsed from the switching time. In the heating operation during the period after defrosting, which is the period until the operation, the compressor is not stopped even if the supply temperature exceeds the first stop temperature.

According to the present invention, it is possible to reduce the frequency of starting and stopping the compressor included in the heating unit that heats the heating medium.

FIG. 3 is a diagram showing a heat medium circulation system according to the first embodiment. FIG. 4 is a diagram showing a circulation circuit of a refrigerant and a heat medium during a heating operation of the heat medium circulation system according to the first embodiment. It is a figure which shows the circulation circuit of the refrigerant at the time of defrosting operation of the heat medium circulation system of Embodiment 1. It is a graph which shows the example of the time variation of an actual supply temperature when operation is switched in order of a heating operation, a defrosting operation, and a heating operation restart.

Hereinafter, embodiments will be described with reference to the drawings. In each drawing, common or corresponding elements are given the same reference numerals to simplify or omit redundant description.

Embodiment 1.
FIG. 1 is a diagram showing a heat medium circulation system 1 according to the first embodiment. As shown in FIG. 1, the heat medium circulation system 1 includes a heat pump device 100, a tank unit 200, and a control device 10. The heat medium circulation system 1 corresponds to a heat pump hot water supply/room heating system. The heat pump device 100 and the tank unit 200 are connected via the first passage 3, the second passage 9 and electric wiring (not shown). The heat pump device 100 is installed outdoors. The tank unit 200 may be installed outdoors or indoors.

The heat medium circulation system 1 according to the first embodiment has a configuration in which the heat pump device 100 and the tank unit 200 are separated. The configuration is not limited to such a configuration, and the heat pump device 100 and the tank unit 200 may be integrated.

The heat pump device 100 according to the first embodiment is an example of a heating unit that heats a liquid heat medium. The heat medium may be liquid water or a liquid heat medium other than water, such as calcium chloride aqueous solution, ethylene glycol aqueous solution, propylene glycol aqueous solution, or alcohol. The heat pump device 100 includes a compressor 13 that compresses a refrigerant, a heat exchanger 15, a decompression device 16 that decompresses the refrigerant, an air heat exchanger 17, and a refrigerant pipe 14 that annularly connects these devices. A refrigerant circuit is provided. The heat pump device 100 performs a heat pump cycle, that is, a refrigeration cycle, in this refrigerant circuit. The refrigerant sealed in the refrigerant circuit may be, for example, carbon dioxide, ammonia, propane, isobutane, CFCs such as HFC, HFO-1123, or HFO-1234yf. The heat exchanger 15 exchanges heat between the high-temperature and high-pressure refrigerant compressed by the compressor 13 and the heat medium. The decompression device 16 decompresses and expands the high-pressure refrigerant that has passed through the heat exchanger 15. The decompression device 16 may be an expansion valve whose opening can be electrically controlled. The refrigerant that has passed through the pressure reducing device 16 flows into the air heat exchanger 17. The air heat exchanger 17 exchanges heat between the outdoor air and the refrigerant. During the heating operation and the heat storage operation, the refrigerant absorbs the heat of the air in the air heat exchanger 17 to evaporate the refrigerant. The heat pump device 100 may include a blower (not shown) that sends outside air to the air heat exchanger 17.

The tank unit 200 includes the heat storage tank 2, the switching valve 6, and the circulation pump 11. A heat medium is stored in the heat storage tank 2. In the heat storage tank 2, it is possible to form a temperature stratification in which the upper side has a high temperature and the lower side has a low temperature due to the difference in specific gravity of the heat medium due to the difference in temperature. A lower inlet passage 18 is connected to the lower portion of the heat storage tank 2. The heat medium having a relatively low temperature flows into the heat storage tank 2 through the lower inlet passage 18. An upper outlet passage 19 is connected to the upper part of the heat storage tank 2. The heat medium stored in the heat storage tank 2 is supplied to the heat demand part (not shown) through the upper outlet passage 19. The heat demand unit may be a hot water supply heat exchanger that heats water by exchanging heat between the heat medium and water. A circulation circuit may be formed so that the heat medium that has passed through the heat demand part returns to the lower portion of the heat storage tank 2 through the lower inlet passage 18. When hot water is stored in the heat storage tank 2 as a heat medium, the hot water is directly supplied from the heat storage tank 2 through the upper outlet passage 19 to a heat demanding part such as a hot water tap, a bathtub, or a shower. Good.

The heat storage tank 2 has an outlet 25 and an inlet 26. The heat medium inside the heat storage tank 2 exits from the outlet 25. The heat medium heated by the heat pump device 100 enters the heat storage tank 2 through the inlet 26. The outlet 25 is at the bottom of the heat storage tank 2. The inlet 26 is located above the heat storage tank 2. The switching valve 6 has a first port 6a, a second port 6b, and a third port 6c. The switching valve 6 has a state in which the third port 6c communicates with the first port 6a and shuts off the second port 6b, and a state in which the third port 6c communicates with the second port 6b and shuts off the first port 6a. Can be switched.

The lower outlet passage 8 connects the outlet 25 of the heat storage tank 2 and the upstream end of the second passage 9. The downstream end of the second passage 9 is connected to the heat medium inlet of the heat exchanger 15 of the heat pump device 100. A circulation pump 11 is connected in the middle of the second passage 9. The operating speed of the circulation pump 11 is variable. The circulation pump 11 may include a pulse width modulation control type DC motor whose operation speed can be changed by a speed command voltage from the control device 10. In the illustrated configuration, the circulation pump 11 is installed in the tank unit 200. Instead of this configuration, the circulation pump 11 may be installed in the heat pump device 100. The first passage 3 connects between the heat medium outlet of the heat exchanger 15 of the heat pump device 100 and the third port 6c of the switching valve 6. The upper inlet passage 4 connects the first port 6 a of the switching valve 6 and the inlet 26 of the heat storage tank 2. In the configuration shown, the circulation pump 11 is connected in the middle of the second passage 9. Instead of this configuration, the circulation pump 11 may be connected in the middle of the first passage 3.

The heating terminal 12 includes at least one heating appliance 24. The heating appliance 24 warms the room by dissipating the heat of the heat medium. As the heating device 24, for example, at least one of a floor heating panel installed under the floor, a radiator or panel heater installed on an indoor wall surface, and a fan convector can be used. When the heating terminal 12 includes a plurality of heating appliances 24, the types thereof may be the same or different. When the heating terminal 12 has a plurality of heating appliances 24, the method of connecting the plurality of heating appliances 24 may be series, parallel, or a combination of series and parallel.

The tank unit 200 and the heating terminal 12 are connected via an external passage 22 and an external passage 23. The tank unit 200 has an outlet 27 and an inlet 28. The heat medium supplied from the tank unit 200 to the heating terminal 12 exits the tank unit 200 from the outlet 27. The third passage 5 connects the second port 6 b of the switching valve 6 and the outlet 27 inside the tank unit 200. The upstream end of the external passage 22 is connected to the outlet 27 from the outside of the tank unit 200. The downstream end of the external passage 22 is connected to the inlet of the heating terminal 12. The upstream end of the external passage 23 is connected to the outlet of the heating terminal 12. The downstream end of the external passage 23 is connected to the inlet 28 from the outside of the tank unit 200. The fourth passage 7 connects the inlet 28 and the upstream end of the second passage 9 inside the tank unit 200. The heat medium returning from the heating terminal 12 to the tank unit 200 enters the tank unit 200 through the inlet 28.

In the illustrated configuration, the control device 10 is installed in the tank unit 200. The control device 10 and the terminal device 21 are connected by wire or wirelessly so that data communication can be performed bidirectionally. The terminal device 21 may be installed in a room provided with the heating appliance 24. The terminal device 21 has a function of receiving a user's operation regarding a driving operation command, a change in a set value, and the like. The terminal device 21 is an example of an operation display terminal or a user interface. The terminal device 21 may include a display that displays information such as the state of the heat medium circulation system 1, an operation unit such as a button or a key operated by the user, a speaker, a microphone, and the like. The heat medium circulation system 1 may include a plurality of terminal devices 21 installed in different places. The display may be any one of a liquid crystal display, an organic EL (Electro-Luminescence) display, and a touch screen having a function of an operation unit. The terminal device 21 may output voice guidance from the speaker. The terminal device 21 functions as a notification unit for the user by performing at least one of the display on the display and the voice guidance from the speaker.

A plurality of temperature sensors (not shown) may be attached to the surface of the heat storage tank 2 at intervals in the vertical direction. The control device 10 can calculate the heat storage amount in the heat storage tank 2 by detecting the temperature distribution in the vertical direction in the heat storage tank 2 with these temperature sensors.

A flow rate sensor 30 and a supply temperature sensor 31 are installed in the middle of the first passage 3. The flow rate sensor 30 detects the volumetric flow rate of the heat medium passing through the first passage 3. In the following description, the temperature of the heat medium flowing out from the heat pump device 100 will be referred to as “supply temperature”. The “supply temperature” during the heating operation corresponds to the temperature of the heat medium supplied from the heat pump device 100 to the heating terminal 12. The supply temperature can be detected by the supply temperature sensor 31. In the first embodiment, the flow rate sensor 30 and the supply temperature sensor 31 are installed in the tank unit 200. Instead of this configuration, the flow rate sensor 30 and the supply temperature sensor 31 may be installed in the heat pump device 100.

A return temperature sensor 32 is provided in the second passage 9. The return temperature sensor 32 detects the temperature of the heat medium flowing into the heat pump device 100. Hereinafter, the temperature of the heat medium flowing into the heat pump device 100 is also referred to as “return temperature”. In the illustrated configuration, the return temperature sensor 32 is installed in the tank unit 200. Instead of this configuration, the return temperature sensor 32 may be installed in the heat pump device 100.

The heating capacity of the heat pump device 100 may be variable. The heating capacity is the amount of heat given to the heat medium by the heat pump device 100 per unit time. The unit of heating capacity is, for example, “watt”. The control device 10 may control the heating capacity by changing the capacity of the compressor 13, for example. The control device 10 may control the capacity of the compressor 13 by changing the rotation speed of the compressor 13, for example. The control device 10 may change the rotation speed of the compressor 13 by inverter control, for example.

Next, the heat storage operation of the heat medium circulation system 1 will be described. The heat storage operation is as follows. The switching valve 6 is in a state where the third port 6c communicates with the first port 6a and the second port 6b is shut off. The heat pump device 100 and the circulation pump 11 are operated. The low-temperature heat medium in the lower part of the heat storage tank 2 is sent to the heat exchanger 15 through the outlet 25, the lower outlet passage 8 and the second passage 9. The high-temperature heat medium heated by the heat exchanger 15 passes through the first passage 3, the third port 6c of the switching valve 6, the first port 6a, the upper inlet passage 4, and the inlet 26, and passes through the upper portion of the heat storage tank 2. Flow into. In the heat storage operation, as the heat medium circulates as described above, the high temperature heat medium accumulates inside the heat storage tank 2 from top to bottom. As a result, the amount of heat stored in the heat storage tank 2 increases. The circulation circuit for the heat medium during the heat storage operation described above is referred to as a "heat storage circuit".

The control device 10 may start the heat storage operation when the heat storage amount in the heat storage tank 2 becomes equal to or lower than a preset low level. When the heat storage operation increases the heat storage amount in the heat storage tank 2 and reaches a preset high level, the control device 10 may end the heat storage operation. The present invention is also applicable to a system that does not include the heat storage tank 2 as described above, that is, a system that does not perform heat storage operation.

Next, the heating operation of the heat medium circulation system 1 will be described with reference to FIG. FIG. 2 is a diagram showing a circulation circuit for the refrigerant and the heat medium during the heating operation of the heat medium circulation system 1 according to the first embodiment. The arrows in FIG. 2 indicate the directions in which the refrigerant and the heat medium flow. In heating operation, it becomes as follows. The switching valve 6 is in a state where the third port 6c communicates with the second port 6b and the first port 6a is shut off. The heat pump device 100 and the circulation pump 11 are operated. The heat medium heated by the heat exchanger 15 of the heat pump device 100 passes through the first passage 3, the third port 6c of the switching valve 6, the second port 6b, the third passage 5, the outlet 27, and the external passage 22. , To the heating terminal 12. The temperature of the heat medium is lowered by being deprived of heat by the room air or the floor while passing through the heating appliance 24 of the heating terminal 12. The heat medium having the lowered temperature passes through the external passage 23, the inlet 28, the fourth passage 7 and the second passage 9 and returns to the heat exchanger 15 of the heat pump device 100. The heat medium returned to the heat exchanger 15 is reheated and recirculated. The circulation circuit of the heat medium during the above heating operation is referred to as a "heating circuit". In the first embodiment, the switching valve 6 can switch between the heat storage circuit and the heating circuit.

An indoor terminal (not shown) including a room temperature sensor may be installed in the room where the heating appliance 24 is provided. The indoor terminal and the control device 10 are connected by wire or wirelessly so that bidirectional data communication is possible. The indoor terminal can transmit information on the room temperature detected by the room temperature sensor to the control device 10. When the terminal device 21 is installed in the room provided with the heating appliance 24, the terminal device 21 may include a room temperature sensor, and the terminal device 21 may transmit the room temperature information to the control device 10. The room temperature detected by the room temperature sensor is hereinafter referred to as “actual room temperature”. The user can set a desired “target room temperature” value using the terminal device 21 or the indoor terminal. The control device 10 may end the heating operation when the actual room temperature reaches the target room temperature based on the information received from the indoor terminal or the terminal device 21.

The supply temperature detected by the supply temperature sensor 31 is hereinafter referred to as "actual supply temperature". During the heating operation and the heat storage operation, the control device 10 can execute the feedback control so that the actual supply temperature becomes equal to the target supply temperature as follows. The control device 10 can control the actual supply temperature by increasing or decreasing the operating speed of the circulation pump 11, that is, by increasing or decreasing the circulation flow rate of the heat medium. When the actual supply temperature is higher than the target supply temperature, the control device 10 can increase the circulation flow rate of the heat medium to reduce the actual supply temperature and bring it closer to the target supply temperature. When the actual supply temperature is lower than the target supply temperature, the control device 10 can increase the actual supply temperature to approach the target supply temperature by reducing the circulation flow rate of the heat medium. The control device 10 may control the actual supply temperature by adjusting the heating capacity of the heat pump device 100 instead of the operating speed of the circulation pump 11. The value of the target supply temperature during the heating operation may be, for example, a value within the range of 25°C to 60°C. The value of the target supply temperature during the heat storage operation may be, for example, a value within the range of 60°C to 80°C.

The control device 10 may determine the target supply temperature in the heating operation by any of the following methods.
(1) The user can set the value of the target supply temperature using the terminal device 21 or the indoor terminal. The controller 10 may determine the value set by the user as the target supply temperature.
(2) The user can preset the relationship between the outside air temperature and the target supply temperature by using the terminal device 21 or the indoor terminal. The control device 10 may determine the target supply temperature based on the relationship and the outside air temperature detected by an outside air temperature sensor (not shown).
(3) The control device 10 uses two or more parameters of the actual room temperature, the target room temperature, the actual supply temperature, the outside air temperature, and the return temperature detected by the return temperature sensor 32 to perform a predetermined calculation or have been prepared beforehand An appropriate target supply temperature may be determined at that time based on a table value or the like.

If the temperature of the heat medium flowing through the heating device 24 is too high during the heating operation, comfort may be impaired, or the temperature may exceed the heat resistant temperature of the heating device 24 and cause a failure. In the heating operation, the control device 10 stops the compressor 13 and the circulation pump 11 when the actual supply temperature exceeds the “first stop temperature”. Accordingly, it is possible to reliably prevent the heat medium having an excessively high temperature from flowing to the heating appliance 24. The control device 10 may determine the first stop temperature based on the target supply temperature. For example, the control device 10 may set a temperature higher than the target supply temperature by a predetermined value as the first stop temperature. For example, the control device 10 may set a temperature that is 2° C. higher than the target supply temperature as the first stop temperature.

When the heating operation is performed under the condition of low outside air temperature, frost may adhere to the air heat exchanger 17. When frost adheres to the air heat exchanger 17, the heat exchange efficiency of the air heat exchanger 17 decreases, and the heating capacity of the heat pump device 100 decreases. When frost adheres to the air heat exchanger 17, the control device 10 temporarily interrupts the heating operation and performs a defrosting operation for melting the frost adhered to the air heat exchanger 17.

The control device 10 determines whether the defrosting operation is required during the heating operation. In the present embodiment, it is possible to determine whether or not the defrosting operation is necessary based on the temperature detected by the defrosting temperature sensor 29. The defrosting temperature sensor 29 detects the temperature of the air heat exchanger 17. The control device 10 determines that the defrosting operation is necessary when the defrosting temperature sensor 29 continuously detects a temperature equal to or lower than a predetermined threshold value for a predetermined time or longer. The threshold may be −3° C., for example. The predetermined time may be, for example, 3 minutes.

FIG. 3 is a diagram showing a refrigerant circulation circuit during the defrosting operation of the heat medium circulation system 1 according to the first embodiment. The arrow in FIG. 3 indicates the direction in which the refrigerant flows. The defrosting operation is as follows. The control device 10 controls the hot gas, which is the high-temperature refrigerant gas compressed by the compressor 13, to flow into the air heat exchanger 17. The opening of the decompression device 16 is fully opened. As a result, it is possible to prevent the temperature of the hot gas from decreasing while passing through the heat exchanger 15 and the pressure reducing device 16. The heat of the hot gas flowing into the air heat exchanger 17 melts the frost. According to the present embodiment, the defrosting operation can be performed without switching the flow path of the refrigerant, so that the defrosting operation can be performed with a simple configuration.

The control device 10 stops the circulation pump 11 during the defrosting operation. As a result, the heat medium does not flow to the heat exchanger 15, so that it is possible to more reliably suppress the heat of the hot gas discharged from the compressor 13 from being taken by the heat medium. As a result, the amount of heat of the hot gas flowing into the air heat exchanger 17 can be further increased, and the defrosting capacity can be further increased.

The control device 10 determines whether or not the frost attached to the air heat exchanger 17 can be removed during the defrosting operation. In the present embodiment, it is possible to determine whether or not frost can be removed based on the temperature detected by defrosting temperature sensor 29. For example, the control device 10 determines that the frost can be removed when the defrosting temperature sensor 29 continuously detects a temperature equal to or higher than a predetermined threshold value for a certain period of time or longer. When it is determined that the frost can be removed, the control device 10 ends the defrosting operation and restarts the heating operation.

FIG. 4 is a graph showing an example of temporal changes in the actual supply temperature when the operation is switched in the order of the heating operation, the defrosting operation, and the heating operation restart. The features of the first embodiment will be described below with reference to FIG.

In the example of FIG. 4, it is as follows. The target supply temperature is 45°C. The first stop temperature is 47°C. In the heating operation until time t1 in FIG. 4, the actual supply temperature is stable at a temperature substantially equal to the target supply temperature. Frost adheres to the air heat exchanger 17 while the heating operation continues. When the control device 10 determines that the defrosting operation is necessary, the heating operation is switched to the defrosting operation. Time t1 corresponds to a switching time point from the heating operation to the defrosting operation. During the defrosting operation, the circulation pump 11 is stopped and the supply of the heat medium to the supply temperature sensor 31 and the heating terminal 12 is stopped. Therefore, from the time t1, the actual supply temperature detected by the supply temperature sensor 31 decreases.

When the control device 10 determines that the frost has been removed by the defrosting operation, the defrosting operation is switched to the heating operation. That is, the heating operation is restarted, the operation of the circulation pump 11 is restarted, and the heat medium is supplied to the supply temperature sensor 31 and the heating terminal 12. Time t2 in FIG. 4 corresponds to a switching time point from the defrosting operation to the heating operation. During the defrosting operation, hot gas from the compressor 13 is supplied to the air heat exchanger 17 through the heat exchanger 15. As a result, the temperature of the heat exchanger 15 during the defrosting operation is higher than the temperature of the heat exchanger 15 before the start of the heating operation. Therefore, the actual supply temperature immediately after switching from the defrosting operation to the heating operation rises faster than the actual supply temperature immediately after the start of the heating operation. As a result, in the feedback control for making the actual supply temperature equal to the target supply temperature, the adjustment of the operating speed of the circulation pump 11 or the adjustment of the heating capacity of the heat pump device 100 cannot keep up with the actual supply temperature, so that the actual supply temperature becomes equal to Easy to overshoot. In the example of FIG. 4, the actual supply temperature rises above the target supply temperature of 45° C. to 49° C., and then changes to stabilize at 45° C.

At time t3 in FIG. 4, the actual supply temperature reaches 47° C. which is the first stop temperature. Assuming that the control device 10 stops the compressor 13 and the circulation pump 11 when the actual supply temperature exceeds the first stop temperature, the compressor 13 and the circulation pump 11 are stopped at time t3. In the example of FIG. 4, the time t3 is about 9 minutes after the time t2 when the defrosting operation is switched to the heating operation. At time t3, it is considered that the actual room temperature has not yet reached the target room temperature, so it is not preferable to stop the compressor 13 and the circulation pump 11.

In view of the above matters, in the present embodiment, control device 10 stops compressor 13 and circulation pump 11 in the heating operation during the post-defrost period even if the actual supply temperature exceeds the first stop temperature. It is configured not to. The “period after defrosting” is a period from the time of switching from the defrosting operation to the heating operation until a predetermined time elapses. In the example shown in FIG. 4, the period from time t2 to time t4 corresponds to the “post-defrost period”. In the example shown in FIG. 4, the length of the predetermined time period, that is, the period after defrosting is 15 minutes. The length of the post-defrost period is not limited to this, and may be, for example, a time in the range of 10 minutes to 1 hour. According to this embodiment, the following effects can be obtained, for example. At time t3 in FIG. 4, the heating operation is continued without stopping the compressor 13 and the circulation pump 11. In this way, it is possible to prevent the compressor 13 and the circulation pump 11 from being stopped when the actual supply temperature sharply rises after the defrosting operation, and thus it is possible to reduce the frequency of starting and stopping the compressor 13 and the circulation pump 11. .. Therefore, in the operation of the heat medium circulation system 1, it is possible to reduce energy loss caused by starting and stopping the compressor 13 and prevent the life of the compressor 13 from being shortened.

It is considered that the actual supply temperature stabilizes in the vicinity of the target supply temperature when a sufficient time has elapsed from the time of switching from the defrosting operation to the heating operation. That is, in the example of FIG. 4, in the heating operation after the time t4, the actual supply temperature is considered to be stable near the target supply temperature. Therefore, in the heating operation after the post-defrost period, it is not necessary to relax the condition of the stop temperature at which the compressor 13 and the circulation pump 11 are stopped. Therefore, in the heating operation after the post-defrost period, when the actual supply temperature exceeds the first stop temperature, the control device 10 stops the compressor 13 and the circulation pump 11. Accordingly, it is possible to reliably prevent the heat medium having a temperature higher than the user's expectation from flowing into the heating terminal 12 in the heating operation after the post-defrost period.

In the present embodiment, control device 10 stops compressor 13 and circulation pump 11 when the actual supply temperature exceeds the “second stop temperature” during the heating operation during the post-defrost period. The “second stop temperature” is higher than the “first stop temperature”. The control device 10 may determine the second stop temperature based on the target supply temperature. For example, the control device 10 may set a temperature higher than the target supply temperature by a predetermined value as the second stop temperature. For example, the control device 10 may set a temperature that is 5° C. higher than the target supply temperature as the second stop temperature. In the example of FIG. 4, the second stop temperature is 50° C. According to the present embodiment, the following effects can be obtained. In the heating operation in the post-defrost period, it is possible to reliably prevent the heat medium having a temperature higher than the second stop temperature from flowing into the heating terminal 12.

The heat medium circulation system 1 may include means for allowing the user to set the value of the parameter for determining the second stop temperature. For example, the following may be done. The control device 10 determines the value obtained by adding the parameter Y to the target supply temperature as the second stop temperature. The value of the parameter Y may be set by the user using the terminal device 21. By doing so, the second stop temperature can be determined more appropriately according to the conditions such as the length of the pipes of the external passages 22 and 23, the number of heating appliances 24, the installation environment, and the like, so that the convenience is improved.

Embodiment 2.
Next, the second embodiment will be described, but the description will focus on the differences from the first embodiment described above, and the description of the same or corresponding parts will be simplified or omitted. Since the hardware configuration of the heat medium circulation system 1 of the second embodiment is the same as that of the first embodiment, the illustration thereof is omitted.

In the second embodiment, the following is done. The "second stop temperature" as in the first embodiment is not set. The control device 10 does not stop the compressor 13 and the circulation pump 11 in the heating operation in the period after defrosting, regardless of the actual supply temperature. As a result, the following effects are obtained. It is possible to more reliably prevent the compressor 13 and the circulation pump 11 from being stopped during the heating operation in the period after defrosting. Therefore, the frequency of starting and stopping the compressor 13 and the circulation pump 11 can be made lower than that in the first embodiment.

In at least one of the first and second embodiments, the heat medium circulation system 1 may include means for allowing the user to set the length of the post-defrost period, that is, the value of the above-mentioned predetermined time. For example, the length of the post-defrost period may be set by the user using the terminal device 21. By doing so, the length of the post-defrost period can be more appropriately determined according to the conditions such as the pipe lengths of the external passages 22 and 23, the number of heating appliances 24, the installation environment, and the like, which is convenient. improves.

In at least one of the first and second embodiments, the control device 10 may stop the compressor 13 regardless of the actual supply temperature when the actual room temperature reaches the target room temperature. That is, when the actual room temperature reaches the target room temperature, the control device 10 stops the compressor 13 even if the actual supply temperature does not exceed the first stop temperature. As a result, it is possible to reliably prevent the room temperature from rising too high and maintain comfort.

The control device 10 may limit the first stop temperature and the second stop temperature so as not to exceed a predetermined upper limit temperature. The upper limit temperature is, for example, a temperature corresponding to the heat resistant temperature of the external passage 22 or the heat resistant temperature of the heating terminal 12. Thereby, the external passage 22 and the heating terminal 12 can be protected more reliably.

In at least one of the first and second embodiments, the heat medium circulation system 1 may include means for notifying the user that the supply temperature may be higher than usual in the post-defrost period. For example, the following may be done. During the heating operation during the period after defrosting, the phrase “high temperature caution” is displayed on the display of the terminal device 21. As a result, the user pays attention not to touch the heating appliance 24, which facilitates active avoidance of discomfort.

In at least one of the first and second embodiments, the control device 10 performs circulation so that the circulation flow rate of the heat medium immediately after the defrosting operation is higher than the circulation flow rate of the heat medium immediately before the defrosting operation. The pump 11 may be operated. As a result, the following effects are obtained. When the circulation flow rate of the heating medium immediately after the defrosting operation is increased, the amount of the heating medium that takes heat from the heat exchanger 15 increases, and thus the actual supply temperature is hard to rise. Therefore, the rise of the actual supply temperature in the heating operation during the post-defrost period can be delayed, and the compressor 13 can be more reliably prevented from being stopped.

In at least one of the first and second embodiments, the following may be done. The control device 10 stores the abnormal heating temperature. The abnormal heating temperature may be 75° C., for example. The abnormal heating temperature is a value for determining an abnormality such as a failure of the heat pump device 100 or a failure of the circulation pump 11 in the heating operation. When the actual supply temperature exceeds the heating abnormal temperature in the heating operation after the defrosting period, the control device 10 stops the compressor 13 and notifies the user of the abnormality by using the terminal device 21. .. On the other hand, in the heating operation in the post-defrost period, the control device 10 does not stop the compressor 13 and does not notify the user of the abnormality even when the actual supply temperature exceeds the heating abnormal temperature. By doing so, it is possible to more reliably prevent the compressor 13 from unnecessarily stopping in the heating operation in the period after defrosting. Further, in the heating operation in the period after defrosting, the control device 10 causes the heat medium from the heat pump device 100 to flow into the heat storage tank 2 instead of the heating terminal 12 when the actual supply temperature exceeds the heating abnormal temperature. Alternatively, the switching valve 6 may be switched. There is no problem even if the temperature of the heat medium flowing into the heat storage tank 2 exceeds the abnormal heating temperature. Therefore, in the heating operation, if the actual supply temperature exceeds the heating abnormal temperature, the heat storage operation is temporarily switched to the heat storage operation without losing the comfort and without wasting the heat of the high-temperature heat medium. Can be stored in 2.

Each function of the controller 10 included in the heat medium circulation system 1 of the first and second embodiments may be realized by a processing circuit. In the illustrated example, the processing circuit of the control device 10 includes at least one processor 10a and at least one memory 10b. When the processing circuit includes at least one processor 10a and at least one memory 10b, each function of the control device 10 may be realized by software, firmware, or a combination of software and firmware. At least one of software and firmware may be written as a program. At least one of software and firmware may be stored in at least one memory 10b. At least one processor 10a may realize each function of the control device 10 by reading and executing a program stored in at least one memory 10b. The at least one memory 10b may include a non-volatile or volatile semiconductor memory, a magnetic disk, or the like.

The processing circuit of the control device 10 may include at least one dedicated hardware. If the processing circuit comprises at least one dedicated hardware, the processing circuit may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-). A Programmable Gate Array) or a combination thereof may be used. The function of each unit of the control device 10 may be realized by a processing circuit. Further, the functions of the respective units of the control device 10 may be collectively implemented by the processing circuit. Part of each function of the control device 10 may be realized by dedicated hardware, and the other part may be realized by software or firmware. The processing circuit may implement each function of the control device 10 by hardware, software, firmware, or a combination thereof.

The configuration is not limited to the configuration in which the operation of the heat medium circulation system 1 is controlled by a single control device, and the configuration may be such that the operation of the heat medium circulation system 1 is controlled by cooperation of a plurality of control devices. ..

1 heat medium circulation system, 2 heat storage tank, 6 switching valve, 10 control device, 11 circulation pump, 12 heating terminal, 13 compressor, 14 refrigerant pipe, 15 heat exchanger, 16 pressure reducing device, 17 air heat exchanger, 21 Terminal device, 24 heating appliances, 29 defrosting temperature sensor, 30 flow rate sensor, 31 supply temperature sensor, 100 heat pump device, 200 tank unit

Claims (9)

An air heat exchanger that exchanges heat between the refrigerant and air, and a compressor that has a compressor that compresses the refrigerant, and heating means that heats a liquid heat medium,
A pump for circulating the heat medium in a circulation circuit passing through a heating terminal and the heating means,
Heating operation electrically connected to the heating means and the pump, supplying the heating medium heated by the heating means to the heating terminal, and defrosting for melting frost adhering to the air heat exchanger. Control means configured to perform driving and
A means for detecting a supply temperature which is a temperature of the heating medium supplied from the heating means to the heating terminal,
Equipped with
The control unit stops the compressor when the supply temperature exceeds a first stop temperature in the heating operation after a predetermined time has elapsed from the switching time from the defrosting operation to the heating operation, and the switching is performed. A heat transfer medium configured not to stop the compressor even when the supply temperature exceeds the first stop temperature in the heating operation in the post-defrosting period, which is a period from the time point until the predetermined time period elapses. Circulation system. The second stop temperature is higher than the first stop temperature,
The heat medium circulation system according to claim 1, wherein the control unit is configured to stop the compressor when the supply temperature exceeds the second stop temperature in the heating operation during the post-defrost period. .. The heat medium circulation system according to claim 1, wherein the control unit is configured not to stop the compressor regardless of the supply temperature during the heating operation during the post-defrost period. The heat medium circulation system according to any one of claims 1 to 3, further comprising a unit that allows a user to set the value of the predetermined time. The heat medium circulation system according to claim 2, further comprising means for allowing a user to set a value of a parameter for determining the second stop temperature. A means for detecting the actual room temperature, which is the temperature of the space in which the heating terminal is installed,
The heat medium according to any one of claims 1 to 5, wherein the control means is configured to stop the compressor regardless of the supply temperature when the actual room temperature reaches a target room temperature. Circulation system. The heat medium circulation system according to any one of claims 1 to 6, further comprising: a unit configured to notify a user that the supply temperature may be higher than usual in the post-defrosting period. The control means is configured to operate the pump so that the circulation flow rate of the heat medium immediately after the defrosting operation is higher than the circulation flow rate of the heat medium immediately before the defrosting operation. The heat medium circulation system according to any one of claims 1 to 7. Equipped with informing means to inform the user of information,
In the heating operation after the period after the defrosting, the control means performs a stop of the compressor and a notification of an abnormality using the notification means when the supply temperature exceeds a heating abnormal temperature, and the defrosting is performed. The device is configured such that, in the heating operation in the latter period, even if the supply temperature exceeds the heating abnormal temperature, the stop of the compressor and the notification of the abnormality using the notification unit are not executed. The heat medium circulation system according to any one of 8 above.

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