JP2016151366A - Hot water heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water heating system capable of properly performing operation control for preventing hot water of a hot water circulation passage from freezing, with an outside air temperature sensor included in a heat pump device.SOLUTION: In an operation stop state of an air blower of a heat pump device, a controller determines whether a detection temperature of an outside temperature sensor is higher than an actual temperature; and when the detection result is affirmative, determines whether a temperature obtained by correcting the detection temperature of the outside temperature sensor satisfies a condition B on an outside temperature among freezing prevention conditions (STEP9).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hot water heating system including a heat pump device as a heat source device.

  2. Description of the Related Art Conventionally, a hot water heating system (for example, a hot water supply system, a heating system, etc.) that heats hot water circulated in a hot water circulation path by an operation of a circulation pump by a heat pump device is generally known. For example, Patent Documents 1 and 2 describe a system that heats hot water for hot water supply using a heat pump device.

  A heat pump device of this type of hot water heating system usually includes an outside air side heat exchanger (evaporator) that exchanges heat between outside air and refrigerant, a blower that blows outside air to the outside air side heat exchanger, and hot water and refrigerant. It includes a hot water side heat exchanger (condenser) that performs heat exchange. Then, the heat pump device circulates the refrigerant so that heat in the outside air is transferred to the refrigerant by the outdoor air side heat exchanger and heat of the refrigerant is radiated to the hot water by the hot water side heat exchanger. By doing so, the warm water circulating in the warm water circulation path is heated by the warm water side heat exchanger.

  Further, in this type of hot water heating system, in order to prevent the hot water in the hot water circulation path from freezing in winter, for example, as seen in Patent Document 2, the temperature of the hot water supplied to the heat pump device Operation control for freezing prevention such as circulating hot water in the hot water circulation path by forcibly operating the circulation pump in a situation where the temperature sensor detects that the outside air temperature is lower than a predetermined threshold temperature. Things to do are also known.

JP 2010-85004 A JP 2014-109422 A

  In the hot water heating system as described above, the heat pump device usually detects the temperature of the air (outside air temperature) supplied to the outside air side heat exchanger (evaporator) by the blower as a sensor for operation control and the like. A temperature sensor is provided.

  And the said outside temperature sensor adjoins to an outside air side heat exchanger on the air path of an air blower, for size reduction etc. of the housing | casing (case where an outside air side heat exchanger, an air blower, etc. are mounted) of a heat pump apparatus. In many cases, they are arranged to face each other.

  On the other hand, in a hot water heating system that appropriately performs operation control for preventing freezing of hot water in the hot water circulation path, the outside air temperature that is one index for determining whether or not to perform operation control for preventing freezing is usually used. The detected temperature of the outside air temperature sensor provided in the heat pump device is used.

  However, in this case, the following inconvenience has been found by the inventor's investigation.

  That is, the blower of the heat pump device is not always operating during operation of the hot water heating system (including the standby state), and the hot water is sufficiently heated and does not require further heating of the hot water by the heat pump device. Etc., the operation of the blower is stopped.

  In this case, since the air around the outside air temperature sensor stays in the state where the operation of the blower of the heat pump device is stopped, the outside air temperature is affected by the residual heat of the outside air heat exchanger for a certain period after the operation of the blower is stopped. The sensor is easy to warm up. As a result, the temperature detected by the outside air temperature sensor may be higher than the actual outside air temperature.

  In such a case, even if the actual outside air temperature satisfies the conditions for executing the operation control for preventing freezing, the detected temperature of the outside air temperature sensor does not satisfy the conditions. A situation occurs in which the operation control for preventing freezing is not executed.

  In order to eliminate such an inconvenience, it is conceivable to dispose the outside temperature sensor sufficiently away from the outside-side heat exchanger, but in this case, the overall configuration of the heat pump device is increased.

  The present invention has been made in view of such a background, and a warm water heating system capable of appropriately performing operation control for preventing freezing of warm water in a warm water circulation path using an outside air temperature sensor provided in the heat pump device. The purpose is to provide.

  In order to achieve the above object, a hot water heating system according to the present invention circulates a hot water circulation path for circulating hot water, an outside air heat exchanger for exchanging heat between the outside air and a refrigerant, and blows outside air to the outside air heat exchanger. A heat pump device for heating the hot water circulated in the hot water circulation path via the hot water side heat exchanger, and a hot water circulation including a blower that performs heat exchange between the hot water and the refrigerant A hot water temperature sensor for detecting the temperature of the hot water supplied to the heat pump device on the road, and facing the outside air heat exchanger on the air passage of the blower, and blown to the outside air heat exchanger by the blower An anti-freezing condition that includes at least an outside air temperature sensor that detects the temperature of the outside air, a condition A related to the detected temperature of the hot water temperature sensor, and a condition B related to the detected temperature of the outside air temperature sensor is established. A warm water heating system comprising a control device configured to perform operation control for preventing freezing of warm water in the warm water circulation path, wherein the control device is in an operation stop state of the blower, When the condition A regarding the temperature detected by the hot water temperature sensor is satisfied, it is determined whether or not the detected temperature of the outside air temperature sensor is higher than the actual temperature, and the determination result is When it is affirmative, it is configured to determine whether or not a temperature obtained by correcting the temperature detected by the outside air temperature sensor satisfies the condition B of the freeze prevention conditions. (First invention).

  According to the first aspect of the invention, when the condition A relating to the detected temperature of the hot water temperature sensor is satisfied in the operation stop state of the blower, the control device detects that the detected temperature of the outside air temperature sensor is an actual temperature. It is determined whether the temperature is higher than that.

  In this case, in the state where the outside air temperature sensor is affected by the residual heat of the outside air side heat exchanger, the above determination result becomes affirmative and is influenced by the residual heat of the outside air side heat exchanger. If not, the above judgment result is negative.

  When the determination result is affirmative, that is, when the outside air temperature sensor is affected by the residual heat of the outside air heat exchanger, the control device detects the outside air temperature sensor. It is determined whether the temperature obtained by correcting the temperature satisfies the condition B of the antifreezing conditions. In this case, the temperature obtained by correcting the detected temperature of the outside air temperature sensor is lower than the detected temperature.

  As a result, even if the outside temperature sensor is affected by the residual heat of the outside air heat exchanger and is higher than the actual actual outside temperature, the actual outside temperature remains at the condition B. In a situation where the condition B is satisfied, it can be determined that the condition B is satisfied with high accuracy. As a result, it is possible to execute the anti-freezing operation control at an appropriate timing.

  Therefore, according to the warm water heating system of the 1st invention, operation control for prevention of freezing of warm water of a warm water circuit can be performed appropriately using the outside temperature sensor with which the heat pump device was equipped.

  In the said 1st invention, when the said heat pump apparatus is equipped with the compressor which compresses the said refrigerant | coolant supplied to the said warm water side heat exchanger, the said outside air side heat exchanger in the operation stop state of the said air blower Residual heat generally attenuates over time after the compressor has stopped operating.

  Therefore, in the first aspect of the invention, when the heat pump device includes the compressor, the control device determines that the detected temperature of the outside air temperature sensor is actually based on at least an elapsed time after the operation of the compressor is stopped. It is preferable to determine whether or not the temperature is higher than the temperature (second invention).

  According to this, it is possible to appropriately determine whether or not the detected temperature of the outside temperature sensor is higher than the actual temperature. As a result, it is possible to appropriately determine whether or not the condition B is satisfied.

The figure which shows the structure of the hot water heating system of one Embodiment of this invention. The flowchart which shows the control processing of the control apparatus with which the warm water heating system of FIG. 1 is equipped.

  An embodiment of the present invention will be described below with reference to FIGS. With reference to FIG. 1, the hot water heating system 1 of this embodiment is, for example, a hot water storage type hot water supply system. The hot water heating system 1 includes a hot water storage tank 2 for storing hot water (hot water) for hot water supply, a heat pump device 3 as a main heat source device for heating the hot water, and a combustion as an auxiliary heat source device for heating the hot water. The type heat source machine 4 is provided.

  In the hot water storage tank 2, the hot water supply path 11 for supplying water to the hot water storage tank 2, the hot water supply path 12 for discharging hot water in the hot water storage tank 2, and the hot water in the hot water storage tank 2 are circulated between the heat pump device 3. The hot water circulation path 13 is connected.

  The water supply path 11 has a downstream end connected to the lower part of the hot water storage tank 2 and an upstream side connected to a water supply source (not shown). A check valve 14 for preventing the backflow of water and a temperature sensor 15 for detecting the temperature of water supplied from the water supply path 11 to the hot water storage tank 2 are mounted on the water supply path 11.

  A water supply bypass 16 is branched from the water supply 11 on the upstream side of the check valve 14. The water supply bypass passage 16 is a flow passage for bypassing the hot water storage tank 2 from the water supply passage 11 and flowing water to the hot water supply passage 12, and its downstream end is connected to the hot water supply passage 12 via a mixing valve 21 described later. ing.

  A check valve 17 for preventing the backflow of water and a flow rate sensor 18 for detecting the flow rate of water flowing through the water supply bypass passage 16 to the hot water supply passage 12 are mounted on the water supply bypass passage 16.

  The hot water supply passage 12 is led out from the upper part of the hot water storage tank 2 and is disposed so as to reach one or a plurality of hot water supply target locations (for example, a kitchen, a washroom, etc.) after passing through the combustion heat source unit 4. .

  A downstream end of the water supply bypass passage 16 is connected to a middle portion of the hot water supply passage 12 on the upstream side of the combustion heat source device 4 via a mixing valve 21. The mixing valve 21 supplies water supplied from the water supply passage 11 via the water supply bypass passage 16 and hot water (hot water) supplied from the hot water storage tank 2 via the hot water supply passage 12 upstream of the mixing valve 21. It is a valve that can be mixed and its mixing ratio (flow rate ratio) can be variably controlled. By controlling the mixing ratio by the mixing valve 21, it is possible to adjust the temperature of the hot water flowing out from the mixing valve 21 to the downstream hot water supply passage 12.

  Instead of the mixing valve 21, for example, a flow rate control valve may be provided in the water supply bypass passage 16 and the hot water supply passage 12.

  A hot water supply path 12 between the mixing valve 21 and the hot water storage tank 2 (a hot water supply path 12 on the upstream side of the mixing valve 21) flows from the hot water storage tank 2 to the hot water supply path 12. A flow rate sensor 23 for detecting the flow rate of hot water is attached.

  A temperature sensor 24 for detecting the temperature of hot water flowing out from the mixing valve 21 to the downstream hot water supply passage 12 is mounted on the hot water supply passage 12 between the mixing valve 21 and the combustion heat source device 4.

  A hot water supply bypass path 25 is branched from the hot water supply path 12 between the mixing valve 21 and the combustion heat source unit 4. The hot water supply bypass path 25 is a flow path for allowing hot water flowing out from the mixing valve 21 to flow downstream to the combustion heat source unit 4 and flowing to the downstream side of the hot water supply path 12. It joins the hot water supply path 12 on the downstream side. The hot water supply bypass 25 is equipped with a bypass control valve 26 constituted by an electromagnetic valve capable of opening / closing control or an electromagnetic valve capable of flow control.

  Furthermore, in the hot water supply path 12 on the downstream side of the combustion type heat source unit 4, the temperature (hot water supply temperature) of hot water (hot water) supplied to the hot water supply target area is located on the downstream side of the joining part of the hot water supply bypass path 25. Is installed.

  The combustion type heat source unit 4 supplies hot water when the hot water storage tank 2 is out of hot water (a state where hot water of a predetermined temperature or more is insufficient), or when hot water cannot be heated by the heat pump device 3 or when the heating is insufficient. This is an auxiliary heat source device for heating hot water flowing from the hot water storage tank 2 to the hot water supply passage 12 when hot water is supplied to the target place.

  The combustion heat source unit 4 includes a burner 31 that burns fuel such as fuel gas or kerosene, and a heat exchanger 32 that is heated by the combustion heat of the burner 31. The hot water supply path 12 in the combustion heat source device 4 is disposed so as to pass through the heat exchanger 32. In addition, a hot water supply passage 12 in the combustion heat source unit 4 is equipped with a hot water supply control valve 33 constituted by an electromagnetic valve capable of opening / closing control or an electromagnetic valve capable of controlling flow rate.

  By controlling the hot water supply control valve 33 and the bypass control valve 26, the flow path of the hot water downstream from the mixing valve 21 is changed from one of the hot water supply path 12 and the hot water supply bypass path 25 on the combustion heat source machine 4 side. It is possible to switch to the other, or to adjust the ratio between the flow rate of hot water in the hot water supply passage 12 on the combustion heat source unit 4 side and the flow rate of hot water in the hot water supply bypass passage 25.

  The hot water circulation path 13 includes a hot water forward path 13 a that supplies hot water from the hot water storage tank 2 to the heat pump apparatus 3, and a hot water return path 13 b that returns the hot water from the heat pump apparatus 3 to the hot water storage tank 2.

  The hot water outgoing path 13 a is led out from the lower part of the hot water storage tank 2, and its downstream end is connected to a hot water inlet of a hot water side heat exchanger 43 described later of the heat pump device 3.

  The upstream end of the hot water return path 13 b is connected to the hot water outlet of the hot water side heat exchanger 43 of the heat pump device 3, and the downstream end is connected to the upper part of the hot water storage tank 2.

  A circulation pump 35 that circulates the warm water in the warm water circulation path 13 is attached to one of the warm water outbound path 13a and the warm water return path 13b, for example, the warm water outbound path 13a. By the operation of the circulation pump 35, the hot water in the hot water storage tank 2 returns to the hot water storage tank 2 from the hot water storage tank 2 through the hot water forward path 13a, the hot water side heat exchanger 43 of the heat pump device 3, and the hot water return path 13b in this order. It is like that.

  In this embodiment, the circulation pump 35 is mounted on the heat pump device 3, but the circulation pump 35 may be disposed outside the heat pump device 3.

  Further, temperature sensors 36 and 37 for detecting the temperature of the hot water supplied from the hot water storage tank 2 to the heat pump device 3 are mounted on the hot water forward path 13a. In this case, in the present embodiment, the temperature sensors 36 and 37 are mounted at two locations, a location near the upstream end and a location near the downstream end of the warm water outgoing path 13a. These temperature sensors 36 and 37 correspond to the hot water temperature sensor in the present invention.

  The heat pump device 3 includes an outside air side heat exchanger 41 (evaporator) that performs heat exchange between outside air and the refrigerant, a compressor 42 that compresses the refrigerant, and hot water supplied from the hot water storage tank 2 by the hot water circulation path 13. A hot water side heat exchanger 43 (condenser) that performs heat exchange with the refrigerant, an expander 44 that adiabatically expands the refrigerant, the outside air side heat exchanger 41, the compressor 42, the hot water side heat exchanger 43, and the expansion A refrigerant circulation path 45 that circulates refrigerant so as to pass through the machine 44 in order, and a blower 46 that blows outside air (air) to the outside air side heat exchanger 41 are provided. As described above, the hot water side heat exchanger 43 is connected to the warm water circulation path 13a and the warm water return path 13b. Moreover, the air blower 46 is comprised by the rotation fan 46a and the electric motor 46b which rotationally drives this in this embodiment.

  Moreover, in order to defrost the outside air side heat exchanger 41, the heat pump device 3 can flow the refrigerant by bypassing the expander 44 between the hot water side heat exchanger 43 and the outside air side heat exchanger 41. Thus, a soot refrigerant bypass passage 47 connected to the refrigerant circulation passage 45 is provided. The refrigerant bypass passage 47 is provided with a defrost valve 48 constituted by an electromagnetic valve that can be controlled to open and close.

  Further, the heat pump device 3 includes a temperature sensor 49 that detects the temperature of the outside air (outside air temperature) blown to the outside air heat exchanger 41 by the blower 46, and a temperature sensor 50 that detects the temperature of the outside air heat exchanger 41. And are installed. The temperature sensor 49 corresponds to the outside air temperature sensor in the present invention, and is disposed in the housing of the heat pump device 3 so as to face the outside air side heat exchanger 41 on the air passage of the blower 46. Further, the temperature sensor 50 is attached to the outdoor air side heat exchanger 41 at any appropriate place, for example, in the vicinity of the refrigerant inlet of the outdoor air side heat exchanger 41.

  In the heat pump device 3 configured as described above, the blower 46 and the compressor 42 are operated in a state in which the defrost valve 48 is closed during the operation of heating the hot water flowing through the hot water circulation path 13. At this time, the refrigerant that has received heat in the outside air by the outside air heat exchanger 41 and is compressed by the compressor 42 (and thus pressurized and heated), the refrigerant that has been heated to a high temperature The hot water side heat exchanger 43 is supplied from the compressor 42. And the warm water which flows into this warm water side heat exchanger 43 will be heated by heat exchange with the said high temperature refrigerant | coolant.

  Moreover, at the time of the defrost operation which defrosts the external air side heat exchanger 41, the compressor 42 is operated in the state which opened the defrost valve 48 and stopped the operation | movement of the air blower 46. At this time, the refrigerant whose temperature is raised by the compressor 42 is supplied to the outside air side heat exchanger 41 via the hot water side heat exchanger 43 and the refrigerant bypass passage 47. As a result, the outside air heat exchanger 41 is warmed, and consequently, the outside air heat exchanger 41 and its surroundings are defrosted.

  During the defrosting operation, the operation of the circulation pump 35 is stopped in order to prevent the heat of the refrigerant from being taken away by the hot water in the hot water circulation path 13 by the hot water side heat exchanger 43.

  The hot water heating system 1 of the present embodiment further includes a control device 61 that controls the operation of the hot water heating system 1, an operation for starting and stopping the hot water heating system 1 (operation on / off operation), and a target value of the hot water supply temperature. And a remote controller 62 for performing the setting operation and the like. The control device 61 and the remote controller 62 are configured to be able to communicate with each other by wire or wirelessly.

  The control device 61 is configured by an electronic circuit unit including a CPU, RAM, ROM, interface circuit, and the like. In this case, the control device 61 may be configured by a plurality of electronic circuit units that can communicate with each other. For example, the control device 61 is configured by an electronic circuit unit mounted on the tank unit configured to include the hot water storage tank 2 and the mixing valve 21, the combustion heat source unit 4, and the heat pump device 3. Also good.

  The control device 61 receives detection signals from the sensors described above. And the control apparatus 61 performs operation control of the warm water heating system 1 with the mounted program and hardware constitutions. In this case, the control device 61 performs the operation control of the heat pump device 3, the circulation pump 35, the mixing valve 21, the bypass control valve 26, and the hot water supply control valve 33 and the combustion operation control of the burner 31 of the combustion heat source unit 4. Then, operation control of the hot water heating system 1 is performed.

  Next, the operation of the hot water heating system 1 of the present embodiment will be described. First, an operation of heating hot water by the heat pump device 3, an operation of supplying hot water to a hot water supply target place, and a defrosting operation of the heat pump device 3 will be described.

  The control device 61 monitors the amount of hot water above a predetermined temperature in the hot water storage tank 2 based on a detection signal of a temperature sensor (not shown) mounted on the hot water storage tank 2, and in a situation where it is determined that the amount of hot water is small. The heat pump device 3 and the circulation pump 35 are operated so as to heat the hot water in the hot water storage tank 2.

  In this case, more specifically, the control device 61 operates the blower 46 and the compressor 42 of the heat pump device 3 while operating the circulation pump 35. Thereby, the hot water in the hot water storage tank 2 is heated by the hot water side heat exchanger 43 while circulating through the hot water circulation path 13 via the hot water side heat exchanger 43 of the heat pump device 3.

  And the control apparatus 61 will stop operation | movement of the heat pump apparatus 3 and the circulation pump 35, if the amount of hot water more than predetermined temperature reaches more than predetermined amount.

  In addition, when water flow through the hot water supply path 12 is started by opening the currant at a hot water supply target location, the control device 61 detects the water flow based on the detection signals of the flow sensors 18 and 23. At this time, the control device 61 appropriately controls the operation of the mixing valve 21, the bypass control valve 26, the hot water supply control valve 33 of the combustion type heat source unit 4, and the burner 31 of the combustion type heat source unit 4, thereby the temperature sensor 27. The temperature adjustment control is performed so that the hot-water supply temperature detected by the above is substantially equal to the target value set by the remote controller 62.

  In this case, when the temperature of the hot water flowing downstream from the mixing valve 21 can be made to substantially match the target value of the hot water supply temperature by the operation control of the mixing valve 21, the burner 31 of the combustion heat source unit 4 is used. No combustion operation is performed. If the temperature of the hot water flowing out from the mixing valve 21 does not reach the target value of the hot water supply temperature even if the operation of the mixing valve 21 is controlled due to running out of hot water in the hot water storage tank 2, the combustion type The combustion operation of the burner 31 is controlled while water is passed through the hot water supply passage 12 in the heat source unit 4.

  Further, the control device 61 is in a situation where it is determined that the frost formation of the outside heat exchanger 41 of the heat pump device 3 is progressing to some extent based on the detection signals of the temperature sensors 49 and 50 of the heat pump device 3. The defrosting operation of the heat pump device 3 is performed.

  In this defrosting operation, the control device 61 operates the compressor 42 with the defrost valve 48 opened as described above. Further, the control device 61 puts the circulation pump 35 into an operation stop state. Thereby, the outside air side heat exchanger 41 is warmed by the refrigerant heated by the compressor 42, and the outside air side heat exchanger 41 and its surroundings are defrosted.

  Next, operation control for preventing freezing of warm water in the warm water circulation path 13 will be described. First, the outline will be described. The control device 61 satisfies a predetermined antifreezing condition for preventing freezing of hot water in the hot water circulation path 13 during operation of the hot water heating system 1 (power-on state). Whether or not the anti-freezing condition is satisfied, the anti-freezing operation control is executed.

  In the present embodiment, the control device 61 causes the hot water to flow through the hot water circulation path 13 by operating the circulation pump 35 in the operation control for preventing freezing. Thereby, freezing of warm water in warm water circulation way 13 is prevented.

  The anti-freezing condition includes the condition A relating to the actual hot water temperature of the hot water circulation path 13 detected by the temperature sensors 36 and 37 provided in the hot water outgoing path 13 a of the hot water circulation path 13 and the actual temperature detected by the temperature sensor 49. And the condition B related to the outside air temperature.

  In the present embodiment, the condition A is a predetermined threshold temperature TH1 (for example, one of the actual hot water temperatures detected by the temperature sensors 36 and 37 (hereinafter referred to as the hot water temperature sensors 36 and 37) is determined in advance. The condition B that is lower than 10 ° C. is a predetermined threshold temperature TH2 (for example, 3 ° C.) in which the actual outside temperature detected by the temperature sensor 49 (hereinafter referred to as the outside temperature sensor 49) is predetermined. It is a condition that the temperature is lower than that.

  In the present embodiment, since the operation control for preventing freezing is the operation control for operating the circulation pump 35, the condition for preventing freezing further includes the condition C that the circulation pump 35 is not operating, and the heat pump device 3. And the condition D that the defrosting operation is not being performed.

  Then, basically, when all of the above conditions A to D are satisfied, the control device 61 executes the operation control for anti-freezing as the anti-freezing condition is satisfied (activates the circulation pump 35). ).

  Here, in the operation stop state of the blower 46 immediately after the end of the heating operation of the hot water by the heat pump device 3, the outside air that faces the outside air side heat exchanger 41 due to the influence of the residual heat of the outside air side heat exchanger 41. In some cases, the detected value (detected temperature) of the outside air temperature by the temperature sensor 49 is higher than the actual outside temperature.

  Therefore, in the operation stop state of the blower 46, the control device 61 causes the outside air temperature sensor 49 to be higher than the actual outside air temperature due to the influence of the residual heat of the outside air heat exchanger 41 when at least the condition A is satisfied. It is determined whether or not it is in the state. If the determination result is affirmative, one of the detected temperature of the outside temperature sensor 49 and the threshold temperature TH2 (3 ° C.), for example, a threshold temperature obtained by correcting the threshold temperature TH2, It is determined whether or not the condition B is satisfied.

  Based on the above outline, a process for determining whether or not the anti-freezing condition is satisfied (hereinafter referred to as an anti-freezing determination process) will be specifically described with reference to FIG.

  Whether or not the detected temperature (detected value of the hot water temperature of the hot water circulation path 13) of any one of the hot water temperature sensors 36 and 37 is lower than a predetermined threshold temperature TH1 (for example, 10 ° C.) in STEP1. It is determined whether or not (the condition A is satisfied). If the determination result is negative, the anti-freezing condition is not satisfied, and the control device 61 continuously repeats the determination process of STEP1.

  If the determination result in STEP 1 is affirmative (when condition A is satisfied), the control device 61 further determines a predetermined temperature (detected value of the outside air temperature) detected by the outside air temperature sensor 49 in STEP 2. It is determined whether the temperature is lower than the threshold temperature THx1.

  Here, the threshold temperature THx1 is set to a temperature (for example, 18 ° C.) sufficiently higher than the threshold temperature TH2 related to the condition B. For this reason, the situation in which the determination result of STEP 2 is negative (the situation where the detected value of the outside air temperature ≧ THx1), even if the outside air temperature sensor 49 is affected by the residual heat of the outside air side heat exchanger 41 ( Even if the temperature detected by the outside air temperature sensor 49 is higher than the actual outside air temperature), the actual outside air temperature is sufficiently high, and it is impossible for the hot water to freeze. .

  If the determination result in STEP 2 is negative, the freeze prevention condition is not satisfied, and the control device 61 repeats the processing from STEP 1.

  If the determination result in STEP 2 is positive, the control device 61 further determines whether or not the blower 46 of the heat pump device 3 is operating in STEP 3 prior to determining whether or not the condition B is satisfied. Determine whether.

  When the blower 46 is operating, such as during the heating operation of the hot water by the heat pump device 3, and the determination result in STEP 3 is affirmative, the control device 61 then detects the outside air temperature sensor 49 in STEP 4. It is determined whether or not the temperature (the detected value of the outside air temperature) is lower than the predetermined threshold temperature TH2 (whether or not the condition B is satisfied).

  In this case, since the blower 46 is operating, the detected temperature of the outside air temperature sensor 49 matches or substantially matches the actual outside air temperature. Further, since the determination process of STEP4 is performed in a situation where the determination result of STEP1 is affirmative, when the determination result of STEP4 is affirmative, both of the condition A and the condition B are satisfied. . In this case, if the operation of the circulation pump 35 is stopped, the hot water in the hot water circulation path 13 may be frozen.

  Therefore, the control device 61 is operating the circulation pump 35 when the determination result of STEP 4 is affirmative (when both the condition A and the condition B are satisfied) while the blower 46 is operating. (Whether the condition C is satisfied) and whether the heat pump device 3 is being defrosted while the circulation pump 35 is deactivated (whether the condition D is satisfied). ) Are determined in STEP 5 and 6, respectively.

  And the control apparatus 61 is the said condition D that the said condition C that the determination result of both STEP5 and 6 is negative, ie, the said circulating pump 35 is not operating, is satisfied, and it is not in defrost operation. In step 7, it is determined that the anti-freezing condition for performing the anti-freezing operation control for operating the circulation pump 35 is satisfied. In response to this, the control device 61 operates the circulation pump 35 as operation control for preventing freezing.

  Further, when the determination result of any one of STEPs 5 and 6 is affirmative, that is, when the circulation pump 35 is in operation or the heat pump device 3 is in the defrosting operation, the antifreezing condition is Since the situation is not established, the control device 61 repeats the processing from STEP1. When the defrosting operation of the heat pump device 3 is being performed in STEP 6, if the conditions A and B are continuously satisfied after the defrosting operation is completed, the antifreezing condition is satisfied.

  In STEP 3, when the blower 46 is not in operation, such as the situation after the heating operation of the hot water by the heat pump device 3, the control device 61 determines that the detected temperature of the outside air temperature sensor 49 is the outside air side heat exchange in STEP 8. It is determined whether or not the temperature is higher than the actual outside air temperature due to the influence of the residual heat of the vessel 41. In this embodiment, this determination is made based on whether or not the elapsed time after the operation of the compressor 42 of the heat pump device 3 has stopped reaches a predetermined time Ta (for example, 60 minutes) or more.

  For the predetermined time Ta, after the operation of the compressor 42 is stopped, the residual heat of the outside air side heat exchanger 41 is sufficiently eliminated within the period of the predetermined time Ta, and the residual heat becomes the detected temperature of the outside air temperature sensor 49. The time when there is no influence is set in advance based on experiments and the like.

  Therefore, in STEP 8, when the elapsed time after the operation of the compressor 42 of the heat pump device 3 is stopped exceeds the predetermined time Ta (when the determination result in STEP 8 is affirmative), the detected temperature of the outside air temperature sensor 49 is detected. However, it is not affected by the residual heat of the outside air side heat exchanger 41, and is in a state that matches or substantially matches the actual outside air temperature.

  In this case, the control device 61 executes the processing from STEP4. In this case, in STEP 4, the detected temperature of the outside air temperature sensor 49 is directly compared with the threshold temperature TH2, and it is determined whether or not the condition B is satisfied.

  On the other hand, when the elapsed time after the operation of the compressor 42 of the heat pump device 3 has not exceeded the predetermined time Ta in STEP 8 (when the determination result in STEP 8 is negative), the detected temperature of the outside air temperature sensor 49 is detected. Can be regarded as a situation where the temperature is higher than the actual outside air temperature due to the influence of the residual heat of the outside air side heat exchanger 41.

  In this case, next, in STEP 9, the control device 61 sets the temperature detected by the outside air temperature sensor 49 to the threshold temperature TH2 (for example, 3 ° C.) according to the condition B of the antifreezing conditions. It is determined whether the temperature is lower than a corrected threshold temperature (= TH2 + α) obtained by adding the temperature correction value α (for example, 3 ° C.).

  In this case, the temperature correction value α is obtained from the detected temperature of the outside air temperature sensor 49 that is affected by the residual heat of the outside air side heat exchanger 41 when the actual outside air temperature is lower than the threshold temperature TH2. The temperature obtained by subtracting the temperature correction value α (the temperature obtained by correcting the detected temperature to the low temperature side) is set in advance based on experiments or the like so that the temperature is surely lower than the threshold temperature TH2.

  Supplementally, in STEP 9, the process of determining whether or not the detected temperature of the outside air temperature sensor 49 is lower than TH2 + α is a temperature obtained by correcting the detected temperature of the outside air temperature sensor 49 with the temperature correction value α (= detection). This is equivalent to the process of determining whether or not the temperature −α) is lower than the threshold temperature TH2.

  When the determination result in STEP 9 is negative, it can be considered that the actual outside air temperature is higher than the threshold temperature TH2 (3 ° C.) according to the condition B of the antifreezing conditions. In this case, the control device 61 repeats the processing from STEP 1 assuming that the freeze prevention condition is not satisfied.

  Further, when the determination result in STEP 9 is affirmative, it can be considered that the actual outside air temperature is lower than the threshold temperature TH2 (3 ° C.) according to the condition B of the antifreezing conditions. . In this case, the control device 61 determines that the condition B is satisfied, and determines whether or not the conditions C and D among the freeze prevention conditions are satisfied in STEPs 5 and 6.

  According to the embodiment described above, the operation of the blower 46 is stopped, and the detected temperature of the outside air temperature sensor 49 becomes higher than the actual outside air temperature due to the influence of the residual heat of the outside air side heat exchanger 41. When the temperature detected by the outside air temperature sensor 49 is compared with the threshold temperature corrected by the temperature correction value α (= TH2 + α) (when the determination result of STEP 8 is negative) ( In other words, by comparing the temperature obtained by correcting the detected temperature of the outside air temperature sensor 49 with the temperature correction value α (detected temperature −α) with the temperature threshold value TH2, the condition B among the antifreezing conditions is A determination is made as to whether or not it is established.

  For this reason, it is possible to appropriately determine whether or not the anti-freezing condition is satisfied, and the operation control is not performed even though the operation control for anti-freezing is necessary or desirable. Can be prevented.

  Next, some modifications related to the above-described embodiment will be described. In the embodiment, in the determination process of STEP 8 for determining whether the detected temperature of the outside air temperature sensor 49 is higher than the actual outside air temperature due to the influence of the residual heat of the outside air heat exchanger 41, The predetermined time Ta was set to a certain time. However, in order to further improve the reliability of the determination whether the detected temperature of the outside air temperature sensor 49 is higher than the actual outside air temperature due to the influence of the residual heat of the outside air side heat exchanger 41, the predetermined time Ta is used. Is variable depending on, for example, the temperature detected by the temperature sensor 50 (the temperature of the outside air-side heat exchanger 41) and the temperature detected by the outside air temperature sensor 49 when the operation of the compressor 42 is stopped (when the operation is stopped). You may make it set to.

  In the embodiment, the temperature correction value α is a constant value. However, the temperature correction value α may be variably set in accordance with the elapsed time after the operation of the compressor 42 is stopped, taking into account, for example, the temporal change of the residual heat of the outside air heat exchanger 41. . Alternatively, by using an appropriate heat transfer model or the like, the increase amount of the detected temperature of the outside air temperature sensor 49 due to the residual heat of the outside air side heat exchanger 41 is sequentially estimated, and the increase amount is used as the temperature correction value α. May be.

  Moreover, in the said embodiment, in the operation stop state of the air blower 46, it is made to perform the process of said STEP8, 9 only in the condition where the condition A regarding warm water temperature is materialized (under the condition where the judgment result of STEP1 becomes affirmative). However, the processing of STEPs 8 and 9 may be performed in the operation stop state of the blower 46 regardless of whether or not the condition A is satisfied.

  In the embodiment, the determination process in STEP 2 is performed. However, the determination process may be omitted.

  In the above embodiment, the operation control for preventing freezing is performed by operating the circulation pump 35. However, for example, the heater provided in the hot water circulation path 13 is operated, for example, by other methods. Freezing prevention may be performed.

  In the above embodiment, the two hot water temperature sensors 36 and 37 are provided, but only one of the hot water temperature sensors may be provided. The hot water temperature sensor may be attached to the hot water return path 13 b of the hot water circulation path 13.

  Further, the condition A related to the hot water temperature among the freeze prevention conditions is not limited to the condition that the hot water temperature is lower than the predetermined threshold temperature TH1. Similarly, the condition B relating to the outside air temperature is not limited to the condition that the outside air temperature is lower than the predetermined threshold temperature TH2. For example, the condition A or B may be set in consideration of a change with time of these temperatures within a certain time.

  Moreover, in the said embodiment, although the hot water heating system 1 is a hot water supply system, the hot water heating system in this invention is not restricted to a hot water supply system, For example, even if it is hot water heating systems, such as a heating system and a hot water supply heating system, etc. Good.

DESCRIPTION OF SYMBOLS 1 ... Warm water heating system, 3 ... Heat pump apparatus, 13 ... Warm water circuit, 36, 37 ... Warm water temperature sensor, 41 ... Outside air side heat exchanger, 42 ... Compressor, 43 ... Warm water side heat exchanger, 46 ... Blower, 49 ... Outside air temperature sensor, 61 ... Control device.

Claims (2)

A hot water circulation path for circulating hot water, an outdoor air side heat exchanger for exchanging heat between the outside air and the refrigerant, a blower for blowing outside air to the outside air side heat exchanger, and hot water for exchanging heat between the hot water and the refrigerant A heat pump device including a side heat exchanger for heating the hot water circulated in the hot water circulation path through the hot water side heat exchanger, and hot water for detecting a temperature of the hot water supplied to the heat pump device in the hot water circulation path A temperature sensor, an outside air temperature sensor provided on the air path of the blower facing the outside air heat exchanger, and detecting a temperature of the outside air blown to the outside air heat exchanger by the blower; and the hot water temperature sensor When the anti-freezing condition including at least the condition A related to the detected temperature of the outdoor air and the condition B related to the detected temperature of the outside air temperature sensor is satisfied, the operation control for preventing freezing of the hot water in the hot water circulation path is executed. A water heating system comprising a controller configured to,
The controller is in a state where the detected temperature of the outside air temperature sensor is higher than the actual temperature when the condition A related to the detected temperature of the hot water temperature sensor is satisfied in the operation stop state of the blower. If the result of the determination is affirmative, whether or not the temperature obtained by correcting the detected temperature of the outside air temperature sensor satisfies the condition B of the anti-freezing conditions A hot water heating system, characterized in that it is configured to determine. The hot water heating system according to claim 1,
The heat pump device includes a compressor that compresses the refrigerant to be supplied to the hot water side heat exchanger,
The control device is configured to determine whether or not the detected temperature of the outside air temperature sensor is higher than an actual temperature based on at least an elapsed time after the operation of the compressor is stopped. A hot water heating system characterized by being.