WO2012046461A1

WO2012046461A1 - Heat pump water heater

Info

Publication number: WO2012046461A1
Application number: PCT/JP2011/053374
Authority: WO
Inventors: 北村　哲也; 高木　純一; 宏太朗渡邊
Original assignee: 日立アプライアンス株式会社
Priority date: 2010-10-07
Filing date: 2011-02-17
Publication date: 2012-04-12
Also published as: KR101465572B1; JP2012082980A; KR20130041327A; CN103154630A; CN103154630B; JP5487067B2

Abstract

The purpose of the present invention is to provide a highly reliable heat pump water heater capable of detecting an abnormality of a liquid flow path by eliminating conditional factors of the liquid flow path that are different depending on the installation position. This heat pump water heater comprises: a variable capacity compressor (4); a liquid-refrigerant heat exchanger (5) for heating liquid to be heated with a high-temperature, high-pressure refrigerant discharged from the compressor; a liquid temperature detector (15) for detecting the temperature of the liquid to be heated that has been heat exchanged by the liquid-refrigerant heat exchanger; and a controller for controlling the capacity of the compressor. The heat pump water heater includes a liquid flow path through which the liquid to be heated flows from the liquid-refrigerant heat exchanger after being introduced into and then passed through the liquid-refrigerant heat exchanger. The controller controls the capacity of the compressor such that the temperature of the liquid to be heated that has been heat exchanged by the liquid-refrigerant heat exchanger becomes a target liquid temperature. The controller determines that the liquid flow path has an abnormality in the case where the temperature of the liquid to be heated that has been heat exchanged by the liquid-refrigerant heat exchanger is higher than the target liquid temperature when the compressor is operating at a capacity equal to or less than a preset standard capacity.

Description

Heat pump water heater

The present invention relates to a heat pump type water heater in which water boiled by a water-refrigerant heat exchanger is stored in a tank.

A heat pump water heater is known that has a boiling function that drives a heat pump cycle using midnight power or the like to heat low-temperature water and store hot water at a desired temperature in a tank.

In such a heat pump type water heater, a water-refrigerant heat exchanger provided in a heat pump cycle and a tank are connected by a pipe, and water in the tank is circulated in the connected pipe. Boiling is performed by exchanging heat between the water in the tank and the refrigerant of the heat pump cycle.

In heat pump water heaters that perform such boiling, clogged dirt in the water pipes and hardness components (for example, calcium carbonate) contained in the tap water deposit as scales and adhere to the pipes. There is a problem that the water for boiling cannot be circulated due to air clogging due to shortage and the operation is stopped due to equipment abnormality.

In order to cope with this problem, a method for detecting clogging in the water pipe from the relationship between the flow rate of water circulated by the pump and the temperature of the refrigerant flowing out of the water-refrigerant heat exchanger or the temperature of the water (for example, Patent Document 1). Have been proposed).

JP 2010-127574 A

However, the heat pump type hot water heater is different in the pressure of the liquid flowing through the liquid flow path, the flow rate of the liquid to be heated, and the pressure loss of the liquid flow path depending on the installation location. The range between the number of rotations and the minimum number of rotations depends on the installation location. In this case, there is a problem that abnormality detection accuracy varies depending on a place where the heat pump type hot water heater is installed.

For example, if the flow rate control range of the pump is close to the minimum rotation speed of the pump, the abnormality may not be detected even if it should be judged as abnormal, and may be overlooked. In addition, when the pump flow control range is close to the maximum rotation speed of the pump, there is a possibility that the rotation speed will immediately become the maximum rotation speed due to sudden flow fluctuations. There is a risk of detection.

Accordingly, an object of the present invention is to provide a highly reliable heat pump type hot water heater that can detect the abnormality of the liquid flow path by eliminating the factors of the state of the liquid flow path that differs depending on the installation location. To do.

The present invention performs heat exchange with a variable capacity compressor, a liquid-refrigerant heat exchanger that heats a liquid to be heated by a high-temperature, high-pressure refrigerant discharged from the compressor, and the liquid-refrigerant heat exchanger. A liquid temperature detector that detects the temperature of the liquid to be heated; and a controller that controls the capacity of the compressor, and the liquid to be heated is introduced into the liquid-refrigerant heat exchanger to exchange the liquid-refrigerant heat. A liquid flow path that flows out of the liquid-refrigerant heat exchanger after passing through the vessel, and the control unit has a preset target temperature of the heated liquid that has been heat-exchanged in the liquid-refrigerant heat exchanger The capacity of the compressor is controlled to be a liquid temperature, and the temperature of the liquid heat-exchanged by the liquid-refrigerant heat exchanger when the compressor is operating below a preset reference capacity is When the temperature is higher than the target liquid temperature, it is determined that the liquid flow path is abnormal. And wherein the door.

Alternatively, the present invention provides a variable capacity compressor, a liquid-refrigerant heat exchanger that heats a liquid to be heated by a high-temperature, high-pressure refrigerant discharged from the compressor, and heat exchange using the liquid-refrigerant heat exchanger. A liquid temperature detector for detecting the temperature of the heated liquid, a refrigerant temperature detector for detecting the temperature of the refrigerant heat-exchanged by the liquid-refrigerant heat exchanger, and a controller for controlling the capacity of the compressor; The liquid to be heated flows out of the liquid-refrigerant heat exchanger after being introduced into the liquid-refrigerant heat exchanger and passing through the liquid-refrigerant heat exchanger. Controls the capacity of the compressor such that the temperature of the heated liquid exchanged by the liquid-refrigerant heat exchanger becomes a preset target liquid temperature, and performs heat exchange by the liquid-refrigerant heat exchanger. The temperature of the cooled refrigerant is higher than a reference temperature determined based on the target liquid temperature. In the case of, characterized by determining an abnormality of the liquid flow path.

According to the present invention, it is possible to provide a heat pump type hot water heater that can detect the abnormality of the liquid flow path by eliminating the factors of the state of the liquid flow path that differs depending on the installation location.

1 is a system configuration diagram of a heat pump type water heater according to Embodiment 1. FIG. FIG. 3 is a control flow diagram of the heat pump type hot water heater according to the first embodiment. 6 is a graph showing changes in compressor rotation speed and water-refrigerant heat exchanger outlet hot water temperature in a state where there is no clogging in the water pipe in the heat pump hot water supply apparatus according to Example 1. FIG. 6 is a graph showing changes in compressor rotation speed and water-refrigerant heat exchanger outlet hot water temperature in a state where clogging occurs in water piping in the heat pump hot water supply apparatus according to Example 1. FIG. It is a system configuration | structure figure of the heat pump type water heater which concerns on Example 2. FIG. It is a control flow figure of the heat pump type hot water heater concerning Example 2. 6 is a graph showing changes in compressor temperature, water-refrigerant heat exchanger outlet hot water temperature, and water-refrigerant heat exchanger outlet refrigerant temperature in a state where there is no clogging in the water pipe in the heat pump hot water supply apparatus according to Example 2. 6 is a graph showing changes in compressor temperature, water-refrigerant heat exchanger outlet hot water temperature, and water-refrigerant heat exchanger outlet refrigerant temperature in a state where clogging occurs in the water pipe in the heat pump type water heater according to Example 2. FIG. . FIG. 6 is a control flow diagram of a heat pump hot water supply apparatus according to a third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1
The first embodiment relates to a heat pump type water heater that can detect an abnormality (particularly, a decrease in flow rate) occurring in a water flow path with high accuracy.

FIG. 1 is a system configuration diagram of a heat pump type water heater according to the first embodiment. FIG. 2 is a control flow diagram during operation of the heat pump type hot water heater according to the first embodiment. FIG. 3 shows changes over time in the compressor rotation speed and the outlet water temperature of the water-refrigerant heat exchanger in the state where no abnormality has occurred in the water flow path of the heat pump type hot water heater according to the first embodiment. FIG. 4 shows changes over time in the compressor rotation speed and the outlet water temperature of the water-refrigerant heat exchanger when an abnormality (reduction in flow rate) occurs in the water flow path of the heat pump type hot water supply apparatus according to the first embodiment.

The heat pump type hot water supply apparatus according to the first embodiment includes a variable capacity compressor 4, a water-refrigerant heat exchanger 5 that heats water using a high-temperature, high-pressure refrigerant discharged from the compressor 4, and water-refrigerant heat exchange. The water temperature detection part 15 which detects the temperature of the water heat-exchanged with the container 5 and the control part 20 which controls the capacity | capacitance of a compressor are provided. The heat pump type water heater has a water flow path F through which water flows out of the water-refrigerant heat exchanger 5 after being introduced into the water-refrigerant heat exchanger 5 and passing through the water-refrigerant heat exchanger 5.

In addition, this heat pump type water heater includes a tank 9 for storing hot water heated by the water-refrigerant heat exchanger 5, a tank unit 2 for accommodating the tank 9, a compressor 4 and a water-refrigerant heat exchanger 5. A heat pump unit 1 to be housed. The water flow path F is provided across the tank unit 2 and the heat pump unit 1.

Specifically, this heat pump type water heater includes a heat pump unit 1 in which a refrigeration cycle including a water-refrigerant heat exchanger 5 shown on the left side of FIG. 1 is mounted inside a casing, and a tank 9 shown on the right side of the drawing. And a tank unit 2 in which the hot water supply circuit is mounted inside the box. And the heat pump unit 1 and the tank unit 2 have a structure connected using the connection piping 3 in the installation place of a heat pump type water heater. The tank 9 often stores hot water, and in this case is called a hot water storage tank.

The refrigeration cycle includes a compressor 4 that compresses refrigerant, a water-refrigerant heat exchanger 5 that exchanges heat between the high-temperature and high-pressure refrigerant discharged from the compressor 4 and water introduced from the tank 9, and water-refrigerant heat. The pressure reducing valve 6 for reducing the pressure of the refrigerant flowing out of the exchanger 5 and the evaporator 7 for exchanging heat with the air for the low-temperature and low-pressure pressure reduced by the pressure reducing valve 6 are connected in an annular manner via a refrigerant pipe. It has a configuration. The evaporator 7 has a structure in which outside air is ventilated by a fan 8. In this refrigeration cycle, carbon dioxide is used as a refrigerant.

The compressor 4 is capacity-controlled by the controller 20 so that the temperature of the hot water heat-exchanged by the water-refrigerant heat exchanger 5 becomes a preset target hot water temperature. Specifically, the compressor 4 is an inverter compressor whose capacity is controlled by controlling the rotation speed of the compressor. However, it is not limited to this, For example, the compressor which performs capacity control by returning the discharged refrigerant to the suction side may be used. The compression method of the compressor is a scroll method, but may be a rotary method or a reciprocating method.

The water cycle includes a tank 9 for storing a necessary amount of hot water, a pump (circulation pump) 10 for guiding water at the bottom of the tank 9, and a water-refrigerant that exchanges heat discharged from the pump (circulation pump) 10 with refrigerant. The heat exchanger 5 is annularly connected by a circulation pipe, and the water discharged from the water-refrigerant heat exchanger 5 is returned to the top of the tank 9. In other words, in the first embodiment, the water flow path F has a portion where water is taken out from the tank 9 as a starting point and a portion where hot water is returned to the tank 9 as an end point. The bottom of the tank 9 is connected to a water supply source such as a water supply (not shown) via a water supply pipe 11, and a hot water supply pipe 12 for supplying hot water to a hot water supply terminal such as a faucet or a shower is connected to the top.

The compressor 4 is provided with a compressor temperature sensor 13 for measuring the casing temperature. Thereby, the temperature of the refrigerant discharged from the compressor 4 (refrigerant discharge temperature) can be detected. The refrigerant discharge temperature may be a temperature detected by a temperature sensor provided in the refrigerant discharge pipe. However, the detection of the casing temperature of the compressor 4 as the refrigerant discharge temperature can suppress the fluctuation of the refrigerant temperature and can control the compressor 4 more easily than the temperature of the refrigerant discharge pipe. Has merit.

A water-cycle refrigerant heat exchanger serving as a water temperature detecting unit 14 for detecting the temperature of water flowing into the water-refrigerant heat exchanger 5 is provided in a water cycle pipe provided before and after the water-refrigerant heat exchanger 5. An inlet water temperature sensor and a water-refrigerant heat exchanger outlet hot water temperature sensor are provided as a water temperature detector 15 for measuring the temperature of water flowing out of the water-refrigerant heat exchanger 5.

In the heat pump type hot water heater, when the compressor 4 is operating at a preset reference capacity or less, the temperature of the water exchanged by the water-refrigerant heat exchanger 5 is higher than the target hot water temperature. It is determined that the water flow path is abnormal. In this way, it is possible to detect an abnormality in the water flow path by eliminating factors of the state of the water flow path that differ depending on the installation location. Further, in the refrigeration cycle including the compressor, the pressure of the fluid, the pressure loss, and the like are not greatly different depending on the installation location of the heat pump type hot water heater, so that the abnormality of the water flow path F is detected based on the rotation speed of the pump Compared to the above, the detection accuracy can be increased.

Moreover, in this heat pump type water heater, since the water flow path F is provided across the tank unit 2 and the heat pump unit 1, the control of the first embodiment performs the abnormality of the water flow path F for the following reason. It is suitable for detecting with high accuracy. In a general heat pump type water heater, the tank 9 and the refrigeration cycle in which the water-refrigerant heat exchanger 5 is housed are configured as separate units. In this case, the state of the water flow path F (pipe resistance and the like) varies greatly depending on the heat pump type hot water heater, depending on the shape and length of the connection pipe 3 performed at the time of installation, the number of bent portions, and the like. In this respect, the heat pump type hot water heater is controlled not based on the flow rate of the water flow path F or the rotation speed of the pump 10, but based on the capacity of the compressor 4. Can be detected.

The reference capacity is set based on the minimum rotation speed of the compressor 4. The minimum rotational speed of the compressor 4 is set to a lower limit value of a rotational speed range determined in advance as a driving range of the compressor 4. Specifically, in order to prevent the malfunction or failure of the compressor 4, it is set slightly higher with a margin than the limit rotational speed at which the compressor 4 can be evaluated as performing refrigerant compression work. . In addition, although the magnitude | size of a margin can be made into arbitrary values according to the characteristic of the compressor 4, it may not give a margin especially.

Specifically, this heat pump type hot water heater is configured so that when the temperature of the water exchanged by the water-refrigerant heat exchanger 5 is higher than the target hot water temperature for a predetermined time or longer, Judge as abnormal. In this way, it is possible to improve the accuracy of the abnormality determination without determining that an accidental change in temperature is abnormal.

In addition, this heat pump type hot water heater determines that the flow rate of the water flowing through the water flow path F is decreased when it is determined to be abnormal by the above method. And the alerting | reporting relevant to the flow volume reduction of the water flow path F is performed. Specifically, an error is displayed on a display screen provided on a remote controller or the like.

Next, a control flow during operation according to the first embodiment will be described with reference to FIG.

During boiling operation, after setting the target hot water temperature and the compressor target temperature to the control unit 20 (S1 in FIG. 2), the boiling operation is started. From the start of the boiling operation, the opening degree of the pressure reducing valve 6 is corrected so that the compressor temperature obtained from the compressor temperature sensor 13 (S2 in FIG. 2) matches the compressor target temperature (S3 in FIG. 2).

Further, the control unit 20 corrects the rotational speed of the compressor 4 so that the outlet hot water temperature (S4 in FIG. 2) obtained by the water temperature detection unit 15 matches the target hot water temperature (S5 in FIG. 2). As a result of this operation, the number of rotations of the compressor that outputs the heating capacity increases or decreases with respect to the amount of circulating water, so that it is possible to accurately grasp the currently output heating capacity.

During the boiling operation in such an operation, when there is no clogging in the piping and the regular water circulation amount is secured, the compressor rotation speed is greatly increased in order to output the regular heating capacity. There is no decline.

However, when abnormalities such as clogging occur in the piping and the regular water circulation amount cannot be secured, the circulation amount of water, which is the liquid to be heated, decreases, and the required heating capacity becomes small. Therefore, since the outlet hot water temperature rises, the control unit 20 reduces the rotational speed of the compressor 4 so that the outlet hot water temperature matches the target hot water temperature.

And if this state progresses, the amount of water circulation will decrease significantly and the compressor 4 will drive | operate with the minimum rotation speed prescribed | regulated by the control part 20. FIG. In order to detect this phenomenon, in this embodiment, a function (S6 in FIG. 2) for monitoring whether or not the rotation speed of the compressor 4 is always operated at a rotation speed higher than the minimum rotation speed during the boiling operation. Provide.

When the compressor 4 is operated at a rotational speed higher than the minimum rotational speed (S6 → No in FIG. 2), the pressure reducing valve opening is changed and the compressor rotational speed is corrected. When the compressor rotational speed is the same as the minimum rotational speed defined (S6 → Yes in FIG. 2), the outlet hot water temperature is confirmed (S7 in the figure). When the confirmed outlet hot water temperature is equal to or lower than the target hot water temperature (S7 → No in FIG. 2), the above-described pressure reducing valve opening change and compressor rotation speed correction are performed. When the outlet hot water temperature is higher than the target hot water temperature (S7 → Yes in FIG. 2), after confirming that the high temperature is maintained even after a predetermined time has passed (S8 in the figure), water circulation error Is issued (S9 in FIG. 2) and the operation is stopped. The predetermined time can also be referred to as a flow rate reduction monitoring time.

Therefore, water clogged due to clogging of dirt in the water pipe, hardness component (for example, calcium carbonate) contained in the tap water deposited as scale, clogged in the pipe, air clogging due to insufficient air venting in the pipe, etc. When a problem that prevents the circulation of a problem occurs, it is possible to detect the problem with a highly accurate and inexpensive method and to promptly respond to the abnormality notification, thereby improving the reliability.

Referring to the experimental example of FIG. 4, the time variation of the compressor rotation speed and the outlet hot water temperature of the water-refrigerant heat exchanger 5 when an abnormality (flow rate decrease) occurs in the water flow path F will be described. After the operation of the compressor 4 is started at time T1, when the water flow path F is abnormal, the rotational speed of the compressor 4 gradually decreases. At time T2, the rotation speed of the compressor 4 becomes the minimum rotation speed. In the experimental example of FIG. 4, the time from time T1 to time T2 is about 5 to 10 minutes. Then, when it is confirmed that the abnormality continues for a predetermined time (flow rate reduction monitoring time) after the state is reached at time T2, the abnormality is notified at time T3. In the experimental example of FIG. 4, the flow rate reduction monitoring time (time T2 to time T3) is about 15 minutes. However, the flow rate reduction monitoring time may be as short as 2 minutes.

In general, abnormalities such as clogging of scales and clogging of small garbage progress gradually (that is, the flow rate decreases). On the other hand, when the valve arranged in the water flow path F is closed, or when a large garbage is clogged, the flow suddenly stops. In this respect, the abnormality detection according to the first embodiment takes about 5 to 10 minutes from the start of controlling the rotation speed of the compressor 4 to detect the abnormality until the minimum rotation speed is reached. Therefore, it is suitable for detecting abnormalities in the decrease in flow rate that progresses little by little.

By adopting such control, the relationship between the outlet hot water temperature and the compressor rotation speed shown in FIG. 3 in a normal state (there is no clogging in the water pipe and the normal water circulation amount is secured), FIG. It is possible to detect the difference in the relationship between the outlet warm water temperature and the compressor rotation speed shown in Fig. 4 during the boiling operation (a state where clogging in the water piping has occurred and the normal amount of water circulation cannot be secured). it can. Therefore, the water circulation abnormality can be reported without erroneous detection, and the boiling operation can be stopped.

(Example 2)
The second embodiment relates to a heat pump type water heater that can detect an abnormality (particularly, a flow stop) occurring in the water flow path F ′ with high accuracy.

FIG. 5 shows a system configuration diagram of a heat pump type water heater according to the second embodiment. FIG. 6 shows a control flow chart during operation of the heat pump type hot water heater according to the second embodiment. FIG. 7 shows temporal changes in the compressor temperature, the outlet refrigerant temperature of the water-refrigerant heat exchanger, and the outlet hot water temperature in a state where no abnormality has occurred in the water flow path of the heat pump type hot water heater according to the second embodiment. FIG. 8 shows temporal changes in the compressor temperature, the outlet refrigerant temperature of the water-refrigerant heat exchanger, and the outlet hot water temperature when an abnormality (flow stoppage) occurs in the water flow path of the heat pump type hot water heater according to the second embodiment. .

The heat pump type hot water heater according to the second embodiment includes a variable capacity compressor 104, a water-refrigerant heat exchanger 105 that heats water using a high-temperature, high-pressure refrigerant discharged from the compressor 104, and water-refrigerant heat exchange. Controls the capacity of the compressor 104, a water temperature detector 115 that detects the temperature of the water heat-exchanged by the condenser 105, a refrigerant temperature detector 116 that detects the temperature of the refrigerant heat-exchanged by the water-refrigerant heat exchanger 105, and the compressor 104 And a control unit 120. The heat pump type hot water heater has a water flow path F ′ that flows out from the water-refrigerant heat exchanger 105 after water is introduced into the water-refrigerant heat exchanger 105 and passes through the water-refrigerant heat exchanger 105.

In addition, this heat pump type water heater includes a tank 109 that stores hot water heated by the water-refrigerant heat exchanger 105, a tank unit 102 that accommodates the tank 109, a compressor 104, and a water-refrigerant heat exchanger 105. A heat pump unit 101 to be housed. The water flow path F ′ is provided across the tank unit 102 and the heat pump unit 101.

Specifically, as shown in FIG. 5, the heat pump type hot water heater includes a heat pump unit 101 in which a refrigeration cycle including a water-refrigerant heat exchanger 105 shown on the left side of the drawing is mounted inside a box, and a right side of the drawing. And a tank unit 102 in which a hot water supply circuit including the tank 109 shown in FIG. The heat pump unit 101 and the tank unit 102 are connected to each other by using a connection pipe 103 at a place where the heat pump type hot water heater is installed.

The tank 109 often stores hot water, and in this case, it may be called a hot water storage tank. The water-refrigerant heat exchanger 105 generally heats water and may be called a water-refrigerant heat exchanger.

The refrigeration cycle includes a compressor 104 that compresses the refrigerant, a water-refrigerant heat exchanger 105 that exchanges heat between the high-temperature and high-pressure refrigerant discharged from the compressor 104 and water introduced from the tank 109, and water-refrigerant heat. A pressure reducing valve 106 for reducing the pressure of the refrigerant flowing out of the exchanger 105, and an evaporator 107 for exchanging heat with air for the low temperature / low pressure refrigerant pressure reduced by the pressure reducing valve 106 are connected in an annular manner via a refrigerant pipe. It has a configuration. The evaporator 107 has a structure in which outside air is ventilated by a fan 108. In this refrigeration cycle, carbon dioxide is used as a refrigerant.

The capacity of the compressor 104 is controlled by the controller 120 so that the temperature of the hot water heat-exchanged by the water-refrigerant heat exchanger 105 becomes a preset target hot water temperature. Specifically, the compressor 104 is an inverter compressor whose capacity is controlled by controlling the rotation speed of the compressor. However, it is not limited to this, For example, the compressor which performs capacity control by returning the discharged refrigerant to the suction side may be used. The compression method of the compressor is a scroll method, but may be a rotary method or a reciprocating method.

The water cycle consists of a tank 109 for storing a required amount of hot water, a pump (circulation pump) 110 to which water at the bottom of the tank 109 is guided, and water discharged from the pump (circulation pump) 110 to exchange heat with refrigerant. The refrigerant heat exchanger 105 is annularly connected by a circulation pipe, and water discharged from the water-refrigerant heat exchanger 105 is returned to the top of the tank 109. In other words, in the second embodiment, the water flow path F ′ has a portion where water is taken out from the tank 109 as a starting point and a portion where hot water is returned to the tank 109 as an end point. The bottom of the tank 109 is connected to a water supply source such as a water supply (not shown) via a water supply pipe 111, and a hot water supply pipe 112 for supplying hot water to a hot water supply terminal such as a faucet or a shower is connected to the top.

The compressor 104 is provided with a compressor temperature sensor 113 for measuring the casing temperature of the compressor 104. Thereby, the temperature of the refrigerant discharged from the compressor 104 (refrigerant discharge temperature) can be detected. The refrigerant discharge temperature may be detected by a temperature sensor provided in the refrigerant discharge pipe. However, detecting the casing temperature of the compressor 104 as the refrigerant discharge temperature can suppress the fluctuation of the refrigerant temperature lower than detecting the temperature of the refrigerant discharge pipe, and it is easier to control the compressor 104. Has merit.

In order to detect the temperature of the refrigerant flowing out of the water-refrigerant heat exchanger 105, the refrigerant pipe downstream of the water-refrigerant heat exchanger 105 has a refrigerant temperature at the outlet of the water-refrigerant heat exchanger as the refrigerant temperature detector 116. A sensor is provided. A water-cycle refrigerant heat exchanger serving as a water temperature detector 114 that detects the temperature of water flowing into the water-refrigerant heat exchanger 5 is provided in a water cycle pipe provided before and after the water-refrigerant heat exchanger 105. An inlet water temperature sensor and a water-refrigerant heat exchanger outlet hot water temperature sensor are provided as a water temperature detector 115 for detecting the temperature of water flowing out of the water-refrigerant heat exchanger 5.

The heat pump type hot water heater determines that the water flow path F ′ is abnormal when the temperature of the refrigerant heat-exchanged by the water-refrigerant heat exchanger 105 is equal to or higher than a reference temperature determined based on the target hot water temperature. In this way, it is possible to detect the abnormality of the water flow path F ′ by eliminating the factors of the state of the water flow path F ′ that differ depending on the installation location. In addition, the refrigeration cycle including the compressor 104 detects an abnormality in the water flow path F ′ based on the number of rotations of the pump because the fluid pressure, pressure loss, and the like do not differ greatly depending on the installation location of the heat pump type hot water heater. Compared with the case where it does, detection accuracy can be raised.

Note that the reference temperature is the same as the target hot water temperature. However, when the capacity of the compressor 104 is controlled so that the temperature of the hot water heat-exchanged in the water-refrigerant heat exchanger 105 becomes the target hot water temperature, the target hot water temperature is temporarily set in the process of increasing the water temperature. There is a case of exceeding (so-called overshoot). Considering this, in this heat pump type hot water heater, the reference temperature is set to be higher by about several degrees Celsius than the target hot water temperature. As a result, even when the temperature of the hot water temporarily exceeds the target hot water temperature, it is not immediately determined as abnormal.

Further, in this heat pump type water heater, since the water flow path F ′ is provided across the tank unit 102 and the heat pump unit 101, the control of the second embodiment is performed for the following reason. It is suitable for detecting anomalies with high accuracy. In a general heat pump type hot water heater, the tank 109 and the refrigeration cycle in which the water-refrigerant heat exchanger 105 is housed are configured as separate units. In this case, the state (pipe resistance, etc.) of the water flow path F ′ varies greatly for each heat pump hot water heater depending on the shape and length of the connection pipe 103 performed at the time of installation, the number of bent portions, and the like. In this respect, this heat pump type hot water heater is controlled based on the capacity of the compressor 104, not based on the flow rate of the water flow path F ′, so that highly accurate detection can be performed regardless of the installation location. Can do.

Specifically, in this heat pump type hot water heater, when the state where the temperature of the refrigerant heat-exchanged by the water-refrigerant heat exchanger 105 is equal to or higher than the target hot water temperature continues for a predetermined time or longer, Judge as abnormal. In this way, it is possible to improve the accuracy of the abnormality determination without determining that an accidental change in temperature is abnormal.

Further, when it is determined that the heat pump type hot water heater is abnormal by the above method, it is determined that the flow of water flowing through the water flow path F ′ is stopped. And the alerting | reporting relevant to the flow of the water of the water flow path F 'having stopped is performed. Specifically, an error is displayed on a display screen provided on a remote controller or the like.

Next, a control flow during operation according to the second embodiment will be described with reference to FIG.

During boiling operation, after setting the target hot water temperature and the compressor target temperature to the control unit 120 (S101 in FIG. 6), the boiling operation is started. From the start of the boiling operation, the opening degree of the pressure reducing valve 106 is corrected so that the compressor temperature obtained from the compressor temperature sensor 113 (S102 in FIG. 6) matches the compressor target temperature (S103 in FIG. 6).

Further, the control unit 120 corrects the rotational speed of the compressor 104 so that the outlet hot water temperature (S104 in FIG. 6) obtained from the water temperature detection unit 115 matches the target hot water temperature (S105 in FIG. 6). As a result of this operation, the number of rotations of the compressor that outputs the heating capacity increases or decreases with respect to the amount of circulating water, so that it is possible to accurately grasp the currently output heating capacity.

During the boiling operation in such an operation, when there is no clogging or the like in the piping and a regular water circulation amount is secured, heat exchange is performed between the water and the refrigerant in the water-refrigerant heat exchanger 105. Since the refrigerant dissipates the stored thermal energy to water, the refrigerant temperature at the outlet of the water-refrigerant heat exchanger becomes lower than the boiling target temperature as shown in FIG.

However, when an abnormality such as clogging occurs in the piping and a normal water circulation amount cannot be secured, the refrigerant cannot radiate heat to the water to be heated in the water-refrigerant heat exchanger 105, so that FIG. As shown, the outlet refrigerant temperature of the water-refrigerant heat exchanger 105 approaches the boiling target temperature.

In order to detect this phenomenon, in this embodiment, the outlet refrigerant temperature of the water-refrigerant heat exchanger 105 is constantly monitored during the boiling operation (S106 in FIG. 6), and the outlet refrigerant temperature is higher than the boiling target temperature. A function for monitoring whether the temperature is lower (S107 in FIG. 6) is provided.

When the outlet refrigerant temperature is lower than the boiling target temperature (S107 → No in FIG. 6), the opening of the pressure reducing valve 106 is changed and the compressor rotational speed is corrected. When the outlet refrigerant temperature becomes higher than the boiling target temperature (S7 → Yes in FIG. 6), after confirming that the high temperature state is maintained even after a predetermined time has elapsed (FIG. 6 during S108 → Yes), a water circulation error is issued (S109 in FIG. 6) and the operation is stopped. The predetermined time can also be referred to as a flow stop monitoring time.

Referring to the experimental example of FIG. 8, the time change of the compressor rotation speed and the outlet refrigerant temperature of the water-refrigerant heat exchanger when abnormality (flow stoppage) occurs in the water flow path F ′ will be described. At time T11, after the operation of the compressor 104 is started, if the water flow path F ′ is abnormal, the outlet refrigerant temperature gradually increases. At time T <b> 12, the outlet refrigerant temperature exceeds the casing temperature of the compressor 104. In the experimental example of FIG. 4, the time from time T11 to time T12 is about 1 to 2 minutes. Then, when it is confirmed that the abnormality continues for a predetermined time (flow stop monitoring time) after the state is reached at time T12, the abnormality is notified at time T13. In the experimental example of FIG. 8, the flow stop monitoring time (time T12 to time T13) is about 2 minutes.

In general, abnormalities such as clogging of scales and clogging of small garbage progress gradually (that is, the flow rate decreases). On the other hand, when the valve disposed in the water flow path F ′ is closed or when a large garbage is clogged, the flow suddenly stops. In this regard, in the abnormality detection according to the second embodiment, the time from the start of heating in the abnormal state until the outlet hot water temperature exceeds the casing temperature of the compressor 104 is about 1 to 2 minutes, and the change is relatively Since it is steep, it is suitable for detecting abnormalities in sudden flow stoppage.

By adopting such control, the normal relationship between the outlet refrigerant temperature and the outlet hot water temperature of the water-refrigerant heat exchanger 105 shown in FIG. 7 (there is no clogging in the water pipe, and a normal water circulation amount is ensured. 8) and the relationship between the outlet refrigerant temperature and outlet hot water temperature of the water-refrigerant heat exchanger 105 shown in FIG. 8 at the time of abnormalities (clogging in the water piping, etc. has occurred, making it impossible to secure a regular amount of water circulation) Change in the state) can be detected during boiling operation. Therefore, the water circulation abnormality can be reported without erroneous detection, and the boiling operation can be stopped. Further, since the abnormality detection is determined at the boiling target temperature, the water circulation abnormality can be reported without erroneous detection and the boiling operation can be stopped regardless of what value the boiling target temperature is set to.

(Example 3)
Since the heat pump type water heater according to the third embodiment has a structure that is basically the same as that of the heat pump type hot water heater according to the second embodiment shown in FIG. I will omit it.

The third embodiment is a heat pump that can detect both the abnormality in the flow rate decrease that occurs in the water flow path F described in the first embodiment and the abnormality in the flow stop that occurs in the water flow path F ′ described in the second embodiment. It relates to a water heater.

That is, in the heat pump type hot water heater according to the third embodiment, the temperature of water heat-exchanged by the water-refrigerant heat exchanger 105 when the compressor 104 is operating below a preset reference capacity is the target hot water temperature. If the temperature is higher than the target hot water temperature, it is determined that the flow rate of the water flowing through the water flow path F ′ is decreasing, and the temperature of the refrigerant exchanging heat in the water-refrigerant heat exchanger 105 is equal to or higher than the target hot water temperature. It is determined that the water flow in the path F ′ is stopped.

Since the abnormality detection of the flow rate reduction in the third embodiment is the same as that described in the first embodiment and the abnormality detection of the flow stop is the same as that described in the second embodiment, the description of the specific control contents is omitted.

Note that steps S201 to S205 in FIG. 9 correspond to steps S1 to S5 of the first embodiment and steps S101 to S105 of the second embodiment, respectively. Step S206 corresponds to step S106 of the second embodiment. Steps S207 to S209 correspond to steps S6 to S8 of the first embodiment. Steps S211 to S212 correspond to steps S107 to S108 of the second embodiment. Step S210 corresponds to step S9 of the first embodiment and step S109 of the second embodiment.

In general, abnormalities such as clogging of scales and clogging of small garbage progress gradually (that is, the flow rate decreases). On the other hand, an abnormality such as a valve disposed in the water flow path F 'being closed or a large clogging of dust is one in which the flow suddenly stops. In this respect, abnormality detection for detecting that the temperature of water heat-exchanged by the water-refrigerant heat exchanger 105 is higher than the target hot water temperature when the compressor 104 is operating at a preset reference capacity or less. Since the time required for detecting an abnormality is relatively long, it is suitable for detecting an abnormality of a flow rate decrease that progresses gradually. On the other hand, the abnormality detection for detecting that the temperature of the refrigerant heat-exchanged in the water-refrigerant heat exchanger 105 is equal to or higher than a reference temperature determined based on the target hot water temperature is abrupt because the time required for abnormality detection is relatively short. Suitable for detecting abnormalities in the flow stop that occurs.

Therefore, according to the heat pump type water heater according to the third embodiment, any abnormality of flow rate decrease or flow stoppage can be detected with high accuracy. In addition, even if the flow rate is suddenly reduced (for example, when medium-sized debris is clogged), the flow rate is reduced or the flow is stopped. It can be detected reliably.

In addition, the heat pump type water heater according to the present invention is not limited to the configuration of the above embodiment, and various modifications can be made without departing from the spirit of the invention.

For example, in the above embodiment, water has been described as an example of the liquid to be heated (liquid to be heated). However, the present invention is not limited to this, and the liquid to be heated (liquid to be heated) is a liquid other than water (for example, , Heat storage liquid, etc.). As such a heat pump type hot water supply device, for example, there is a system in which a high temperature liquid heated by a heat pump is stored in a tank, and hot water is indirectly heated using this high temperature liquid to supply hot water. It is done. In this case, the water-refrigerant heat exchanger can be read as a liquid-refrigerant heat exchanger, the hot water temperature and the water temperature can be read as the liquid temperature, and the water flow path is read as the liquid flow path. be able to.

Moreover, in the said embodiment, although the heat pump type hot water heater which stores the high temperature water heated with the heat pump in the tank was demonstrated to the example, this invention is the hot water heated with the heat pump as it is to the hot water supply terminal. The present invention can also be applied to a heat pump type water heater of the supply type.

In the above embodiment, the heat pump type hot water heater that heats the water stored in the tank by introducing it into the water-refrigerant heat exchanger has been described as an example. However, the present invention uses the water from the water supply source as it is. -It can also be applied to heat pump water heaters that are heated by introduction into a refrigerant heat exchanger.

In the above embodiment, the tank unit 2 that accommodates the tank 9 and the heat pump unit 1 that accommodates the compressor 4 and the liquid-refrigerant heat exchanger 5 are described as examples. However, the present invention is not limited thereto, and a tank, a compressor, and a liquid-refrigerant heat exchanger may be integrally provided in one unit.

1,101 Heat pump unit 2,102 Tank unit 3,103 Connection pipe 4,104 Compressor 5,105 Water-refrigerant heat exchanger 6,106 Pressure reducing valve 7,107 Evaporator 8,108 Fan 9,109 Tank 10,110

Pump

11, 111

Water supply pipe

12, 112 Hot

water supply pipe

13, 113

Compressor temperature sensor

14, 15, 114, 115 Water temperature detection unit 116 Refrigerant temperature detection unit

Claims

A compressor having a variable capacity, a liquid-refrigerant heat exchanger that heats the liquid to be heated by a high-temperature and high-pressure refrigerant discharged from the compressor, and a liquid to be heated that is heat-exchanged by the liquid-refrigerant heat exchanger A liquid temperature detection unit for detecting the temperature, and a control unit for controlling the capacity of the compressor,
A liquid channel that flows out of the liquid-refrigerant heat exchanger after the liquid to be heated is introduced into the liquid-refrigerant heat exchanger and passes through the liquid-refrigerant heat exchanger;
The controller controls the capacity of the compressor so that the temperature of the liquid to be heated exchanged by the liquid-refrigerant heat exchanger becomes a preset target liquid temperature;
If the temperature of the liquid heat exchanged by the liquid-refrigerant heat exchanger is higher than the target liquid temperature when the compressor is operating below a preset reference capacity, A heat pump type water heater characterized by being judged to be abnormal.
When the temperature of the liquid heat-exchanged in the liquid-refrigerant heat exchanger is higher than the target liquid temperature continues for a predetermined time or longer when the compressor is operating below a preset reference capacity The heat pump type hot water heater according to claim 1, wherein it is determined that the liquid flow path is abnormal.
The capacity of the compressor is controlled so that the temperature of the liquid to be heated exchanged by the liquid-refrigerant heat exchanger becomes a target liquid temperature, and the compressor is operating below a preset reference capacity. When the temperature of the liquid heat exchanged by the liquid-refrigerant heat exchanger is higher than the target liquid temperature, a notification related to a decrease in the flow rate of the liquid to be heated in the liquid flow path is performed. The heat pump type water heater according to claim 1.
A compressor having a variable capacity, a liquid-refrigerant heat exchanger that heats the liquid to be heated by a high-temperature and high-pressure refrigerant discharged from the compressor, and a liquid to be heated that is heat-exchanged by the liquid-refrigerant heat exchanger A liquid temperature detection unit for detecting temperature, a refrigerant temperature detection unit for detecting the temperature of the refrigerant heat-exchanged by the liquid-refrigerant heat exchanger, and a control unit for controlling the capacity of the compressor,
A liquid channel that flows out of the liquid-refrigerant heat exchanger after the liquid to be heated is introduced into the liquid-refrigerant heat exchanger and passes through the liquid-refrigerant heat exchanger;
The controller controls the capacity of the compressor so that the temperature of the liquid to be heated exchanged by the liquid-refrigerant heat exchanger becomes a preset target liquid temperature;
A heat pump type water heater characterized by determining that the liquid flow path is abnormal when the temperature of the refrigerant heat-exchanged by the liquid-refrigerant heat exchanger is equal to or higher than a reference temperature determined based on the target liquid temperature. .
If the state where the temperature of the refrigerant heat-exchanged by the liquid-refrigerant heat exchanger is equal to or higher than a reference temperature determined based on the target liquid temperature continues for a predetermined time or more, it is determined that the liquid flow path is abnormal. The heat pump type water heater according to claim 4, wherein
When the temperature of the refrigerant heat-exchanged by the liquid-refrigerant heat exchanger is equal to or higher than a reference temperature determined based on the target liquid temperature, the flow of the liquid to be heated in the liquid channel is stopped. The heat pump type hot water heater according to claim 4, wherein notification is performed.
A compressor having a variable capacity, a liquid-refrigerant heat exchanger that heats the liquid to be heated by a high-temperature and high-pressure refrigerant discharged from the compressor, and a liquid to be heated that is heat-exchanged by the liquid-refrigerant heat exchanger A liquid temperature detection unit for detecting temperature, a refrigerant temperature detection unit for detecting the temperature of the refrigerant heat-exchanged by the liquid-refrigerant heat exchanger, and a control unit for controlling the capacity of the compressor,
A liquid flow path for removing the liquid to be heated from the liquid-refrigerant heat exchanger after introducing the liquid to be heated into the liquid-refrigerant heat exchanger and passing through the liquid-refrigerant heat exchanger;
The controller controls the capacity of the compressor so that the temperature of the liquid to be heated exchanged by the liquid-refrigerant heat exchanger becomes a preset target liquid temperature;
If the temperature of the liquid heat-exchanged by the liquid-refrigerant heat exchanger is higher than the target liquid temperature when the compressor is operating below a preset reference capacity, Judge that the flow rate of the liquid to be heated is decreasing,
When the temperature of the refrigerant that has exchanged heat with the liquid-refrigerant heat exchanger is equal to or higher than a reference temperature determined based on the target liquid temperature, it is determined that the flow of the liquid to be heated in the liquid channel is stopped. A heat pump type water heater characterized by that.
A tank for storing a liquid to be heated heated by the liquid-refrigerant heat exchanger;
A tank unit for housing the tank;
A heat pump unit that houses the compressor and the liquid-refrigerant heat exchanger;
The heat pump type hot water supply apparatus according to any one of claims 1, 4, and 7, wherein the liquid flow path is provided across the tank unit and the heat pump unit.