KR101465572B1 - Heat pump water heater - Google Patents

Abstract

An object of the present invention is to provide a highly reliable heat pump type hot water heater capable of detecting an abnormality of a liquid flow path by eliminating factors of conditions of liquid flow paths other than the installation place. A liquid-refrigerant heat exchanger (5) for heating the liquid to be heated by the high-temperature, high-pressure refrigerant discharged from the compressor, and a liquid-refrigerant heat exchanger Refrigerant heat exchanger, and a control unit for controlling the capacity of the compressor. The liquid-refrigerant heat exchanger is provided with a liquid temperature detection unit 15 for detecting the temperature of the liquid refrigerant, And the control unit controls the capacity of the compressor so that the temperature of the liquid to be heat-exchanged in the liquid-refrigerant heat exchanger becomes a predetermined target liquid temperature, and when the compressor is operated at a preset reference capacity or less, When the temperature of the liquid heat exchanged in the unit is higher than the target liquid temperature, it is judged that the liquid flow path is abnormal.

Description

HEAT PUMP WATER HEATER

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type water heater in which boiling water is collected in a tank by a water-refrigerant heat exchanger.

There is known a heat pump type hot water boiler provided with a boiling function for heating a low temperature water to store hot water of a desired temperature in a tank by driving a heat pump cycle using nighttime power or the like.

Such a heat pump type hot water heater is configured such that a water-refrigerant heat exchanger installed in a heat pump cycle and a tank are connected by piping, water in the tank is circulated in the connected piping, and water in the tank and heat pump cycle And boiling is performed by performing heat exchange with the refrigerant.

In such a heat pump type hot water boiler that performs boiling, dust clogging in a water pipe, hardness components (e.g., calcium carbonate) contained in tap water are precipitated as scale, scale clogging adhered to the pipe, air clogging due to lack of air in the pipe, The circulation of the water for boiling can not be performed, and there is a problem that the operation stop due to the abnormality of the apparatus occurs.

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

Japanese Patent Application Laid-Open No. 2010-127574

However, since the heat pump type hot water heater differs from the installation site 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, The range between the minimum number of revolutions will depend on where it is installed. In this case, there is a problem that the detection accuracy is different depending on the place where the heat pump type hot water heater is installed.

For example, when the flow rate control range of the pump is close to the minimum number of revolutions of the pump, there is a fear that the abnormality can not be detected even though the abnormality can be detected. Further, when the flow rate control range of the pump is close to the maximum rotation number of the pump, it is feared that the rotation number may become the maximum rotation number immediately due to a sudden fluctuation of the flow, .

Therefore, it is an object of the present invention to provide a highly reliable heat pump type hot water heater which can detect an abnormality of a liquid flow path by eliminating factors of conditions of liquid flow paths other than the installation place.

The present invention relates to a liquid refrigerant heat exchanger, comprising: a compressor having a variable capacity; a liquid-refrigerant heat exchanger for heating the liquid to be heated by high-temperature and high-pressure refrigerant discharged from the compressor; Refrigerant heat exchanger, and a control unit for controlling the capacity of the compressor. The liquid-refrigerant heat exchanger is characterized in that the liquid-refrigerant heat exchanger And the control unit controls the capacity of the compressor so that the temperature of the liquid to be heat-exchanged in the liquid-refrigerant heat exchanger becomes a predetermined target liquid temperature, and when the compressor is operated at a preset reference capacity or less When the temperature of the liquid heat-exchanged in the liquid-refrigerant heat exchanger is higher than the target liquid temperature, It characterized in that the determination as to the least.

Alternatively, the present invention can be applied to a liquid-refrigerant heat exchanger which has a capacity variable compressor, a liquid-refrigerant heat exchanger which heats the liquid to be heated by the high-temperature and high-pressure refrigerant discharged from the compressor, A refrigerant temperature detection unit for detecting the temperature of the refrigerant heat-exchanged in the liquid refrigerant heat exchanger; and a control unit for controlling the capacity of the compressor, wherein the liquid to be heated is subjected to the liquid-refrigerant heat exchange Refrigerant heat exchanger and the liquid refrigerant flowing out of the liquid refrigerant heat exchanger after passing through the liquid refrigerant heat exchanger, wherein the control unit controls the temperature of the liquid-refrigerant heat exchanger so that the temperature of the heat- And the temperature of the refrigerant heat-exchanged in the liquid-refrigerant heat exchanger is controlled based on the target liquid temperature And judging that the liquid flow path is abnormal when the temperature is equal to or higher than the reference temperature determined by the liquid flow rate determination means.

According to the present invention, it is possible to provide a heat pump type hot water heater capable of detecting an abnormality in the liquid flow path by eliminating factors of conditions of other liquid flow paths depending on installation places.

1 is a system configuration diagram of a heat pump type hot water heater according to Embodiment 1. Fig.
2 is a control flowchart of the heat pump type hot water heater according to the first embodiment;
3 is a graph showing changes in compressor rpm and water-refrigerant heat exchanger outlet hot water temperature in a state in which no clogging occurs in a water pipe in the heat pump type water heater according to Embodiment 1. Fig.
FIG. 4 is a graph showing changes in the compressor rotational speed and the water-refrigerant heat exchanger outlet hot water temperature in a state where clogging occurs in a water pipe in the heat pump type hot water heater according to Embodiment 1. FIG.
5 is a system configuration diagram of a heat pump type hot water heater according to Embodiment 2. Fig.
6 is a control flowchart of the heat pump type hot water heater according to the second embodiment;
7 is a graph showing changes in the compressor temperature, the water-refrigerant heat exchanger outlet hot water temperature, and the water-refrigerant heat exchanger outlet refrigerant temperature in a state where no clogging occurs in the water pipe in the heat pump type water heater according to Embodiment 2 .
8 is a graph showing changes in the compressor temperature, the water-refrigerant heat exchanger outlet hot water temperature, and the water-refrigerant heat exchanger outlet refrigerant temperature in the state where the clogging occurs in the water pipe in the heat pump type hot water heater according to Embodiment 2 .
9 is a control flowchart of the heat pump type hot water heater according to the third embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION 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 hot water heater capable of detecting an abnormality (particularly, a flow rate reduction) occurring in a water flow path with high accuracy.

1 is a system block diagram of a heat pump type hot water heater according to a first embodiment. Fig. 2 is a control flow chart of the operation of the heat pump type hot water heater according to the first embodiment. Fig. Fig. 3 shows a temporal change of the compressor rotational speed and the outlet hot water temperature of the water-refrigerant heat exchanger in a state in which no abnormality occurs in the water flow path of the heat pump type hot water heater according to the first embodiment. 4 shows changes over time in the compressor rotational speed and the outlet hot 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 heater according to the first embodiment.

The heat pump type hot water heater according to the first embodiment includes a compressor 4 having a variable capacity, a water-refrigerant heat exchanger 5 for heating water by high-temperature, high-pressure refrigerant discharged from the compressor 4, A water temperature detecting section 15 for detecting the temperature of water heat-exchanged in the refrigerant heat exchanger 5, and a control section 20 for controlling the capacity of the compressor. The heat pump type hot water heater is configured such that water is introduced into the water-refrigerant heat exchanger 5 and flows through the water-refrigerant heat exchanger 5, (Liquid flow path).

The heat pump type hot water heater includes a tank 9 for storing hot water heated by the water-refrigerant heat exchanger 5, a tank unit 2 for storing the tank 9, a compressor 4 And a heat pump unit (1) for receiving the water-refrigerant heat exchanger (5). The water flow path F is provided across the tank unit 2 and the heat pump unit 1. [

Specifically, the heat pump type hot water heater includes a heat pump unit 1 in which a refrigeration cycle including the water-refrigerant heat exchanger 5 shown in the left side of Fig. 1 is mounted in a housing, And a tank unit (2) in which a hot water supply circuit (9) is mounted in the casing. The heat pump unit 1 and the tank unit 2 are structured so as to be connected using the connection pipe 3 at the installation place of the heat pump type water heater. On the other hand, hot water is often stored in the tank 9, and in this case, it is called a hot water tank.

The refrigeration cycle includes a compressor 4 for compressing a refrigerant, a water-refrigerant heat exchanger 5 for exchanging heat with high-temperature and high-pressure refrigerant discharged from the compressor 4 and water introduced from the tank 9, A pressure reducing valve 6 in which the refrigerant flowing out of the refrigerant heat exchanger 5 is decompressed and an evaporator 7 in which the low temperature and low pressure refrigerant decompressed by the pressure reducing valve 6 exchanges heat with air, As shown in FIG. The evaporator (7) has a structure in which outside air is ventilated by the fan (8). On the other hand, in this refrigeration cycle, carbon dioxide is used as the refrigerant.

The compressor (4) is capacity-controlled by the controller (20) so that the temperature of the hot water heat-exchanged in the water-refrigerant heat exchanger (5) becomes a preset target hot water temperature. Specifically, the compressor (4) is an inverter compressor in which the capacity is controlled by controlling the number of revolutions of the compressor. However, the present invention is not limited to this. For example, it may be a compressor that performs the capacity control by returning the discharged refrigerant to the suction side. 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 collecting a necessary amount of hot water, a pump (circulation pump) 10 for introducing water at the bottom of the tank 9, The water discharged from the water-refrigerant heat exchanger (5) is connected to the top of the tank (9) by a water-refrigerant heat exchanger (5) for exchanging water with the refrigerant in a ring- As shown in Fig. That is, the water flow path F has a portion where water is taken out from the tank 9 as a starting point in the first embodiment, and a portion where hot water is returned to the tank 9 as an end point. A bottom portion of the tank 9 is connected to a water supply source such as water not shown through 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 water heater, .

The compressor (4) is provided with a compressor temperature sensor (13) for measuring the housing temperature. Thus, the temperature (refrigerant discharge temperature) of the refrigerant discharged from the compressor 4 can be detected. On the other hand, the refrigerant discharge temperature may be a temperature which is detected by a temperature sensor provided on the discharge pipe of the refrigerant. However, it is more advantageous to detect the housing temperature of the compressor 4 as the refrigerant discharge temperature than to detect the temperature of the discharge pipe of the refrigerant, and to suppress the fluctuation of the refrigerant temperature to a low level, .

The water-refrigerant heat exchanger (5) is connected to the water-refrigerant heat exchanger (5) by a water-refrigerant heat exchanger inlet (14) serving as a water temperature detecting section (14) for detecting the temperature of water flowing into the water- A water temperature sensor, and a water-refrigerant heat exchanger outlet hot water temperature sensor serving as a water temperature detecting unit 15 for measuring the temperature of water flowing out of the water-refrigerant heat exchanger 5. [

When the temperature of the water heat-exchanged in the water-refrigerant heat exchanger (5) is higher than the target hot water temperature when the compressor (4) is operated at a preset reference capacity or less, the heat pump type hot water heater . In this way, it is possible to eliminate the factor of the state of the water flow path depending on the installation place, and to detect an abnormality in the water flow path. In the refrigeration cycle including the compressor, since the pressure or pressure loss of the fluid is not greatly different from place to place of the heat pump type water heater, when detecting the abnormality of the water flow passage F based on the number of revolutions of the pump The detection accuracy can be enhanced.

In this heat pump type hot 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 has the following advantages: It is suitable for highly accurate detection of the abnormality of the liquid F (F). In the general heat pump type hot water heater, the refrigeration cycle in which the tank 9 and the water-refrigerant heat exchanger 5 are housed is composed of different units separated from each other. In this case, the state (piping resistance, etc.) of the water passage F differs significantly for each heat pump type hot water heater depending on the shape and length of the connection pipe 3, the number of bent portions, and the like. In this respect, the heat pump type hot water heater is controlled based on the capacity of the compressor 4, not on the basis of the flow rate of the water flow path F or the rotational speed of the pump 10, It is possible to perform detection with high accuracy.

On the other hand, the reference capacity is set based on the minimum number of revolutions of the compressor (4). The minimum rotation number of the compressor (4) is set as a lower limit value of a predetermined rotation number range as a drive range of the compressor (4). Concretely, in order to prevent the occurrence of a failure or malfunction of the compressor 4, the compressor 4 is set to a slightly higher margin with a margin higher than the limit rotation speed which can be evaluated as the refrigerant compression operation. On the other hand, the size of the margin can be set to any value according to the characteristics of the compressor 4, but it is not necessary to provide any extra margin.

Specifically, when the temperature of the water heat-exchanged in the water-refrigerant heat exchanger 5 is higher than the target hot water temperature for a predetermined time or more, the heat pump type hot water heater is judged as abnormality of the water flow path F do. In this way, there is no case where the accidental fluctuation of the temperature is judged as abnormal, and the accuracy of the abnormality judgment can be further improved.

This heat pump type water heater determines that the flow rate of the water flowing through the water flow path F is reduced when it is determined in the above manner. Then, a notification related to the decrease in the flow rate of water in the water passage F is performed. Specifically, an error is displayed on a display screen provided on a remote controller or the like.

Next, a control flow at the time of operation according to the first embodiment will be described with reference to Fig.

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

The controller 20 also corrects the number of rotations of the compressor 4 so that the outlet hot water temperature (S4 in FIG. 2) and the target hot water temperature are equal to each other (S5 in FIG. 2). With this operation, since the number of revolutions of the compressor that outputs the heating capacity is increased or decreased with respect to the amount of circulating water, the heating capacity currently outputting can be accurately grasped.

When the boiling operation is performed by this operation, there is no clogging in the piping, and when the regular water circulation amount is secured, the normal heating capacity is outputted, so that the compressor rotation speed is not greatly reduced.

However, when an abnormality such as clogging occurs in the piping and the regular water circulation amount can not be ensured, the amount of circulation of water as the liquid to be heated decreases, so that the required heating capacity is reduced. Therefore, since the outlet hot water temperature rises, the controller 20 lowers the number of revolutions of the compressor 4 so that the outlet hot water temperature and the target hot water temperature coincide with each other.

In this state, the amount of water circulation is greatly reduced, and the compressor 4 is operated at the minimum number of revolutions specified by the controller 20. [ In order to detect this phenomenon, in the present embodiment, a function (S6 in Fig. 2) for monitoring whether the number of revolutions of the compressor 4 is operating at a higher number of revolutions than the minimum number of revolutions is always provided during the boiling operation.

When the number of revolutions of the compressor 4 is operated at the number of revolutions higher than the minimum number of revolutions (S6? No in FIG. 2), the above described opening of the reduced pressure valve and the number of revolutions of the compressor are corrected. When the compressor rotational speed becomes equal to the prescribed minimum rotational speed (S6 → Yes in FIG. 2), the outlet hot water temperature is confirmed (S7 in the figure). When the determined outlet hot water temperature is equal to or lower than the target hot water temperature (S7 - > No in Fig. 2), the above described opening of the reducing valve and the number of revolutions of the compressor are corrected. When the outlet hot water temperature is higher than the target hot water temperature (S7 → Yes in FIG. 2), it is confirmed that the high temperature state is maintained even after a predetermined time elapses (S8 in the figure) S9) and the operation is stopped. On the other hand, the predetermined time may be called a flow decrease monitoring time.

Therefore, the circulation of water that boils by clogging of dust in a water pipe or clogging of scale attached to a pipe due to precipitation of a hard component (for example, calcium carbonate) contained in tap water as scale and air shortage due to shortage of air in the pipe It is possible to detect a problem with high accuracy and inexpensively and to respond promptly by an abnormality notification, thereby improving the reliability.

The time change of the compressor rotational speed and the outlet hot water temperature of the water-refrigerant heat exchanger 5 when an abnormality (reduction in flow rate) occurs in the water passage F will be described with reference to the experimental example of Fig. When the water flow path F has an abnormality after the start of the operation of the compressor 4 at time T1, the number of rotations of the compressor 4 gradually decreases. At time T2, the number of revolutions of the compressor 4 becomes the minimum number of revolutions. 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 predetermined time (flow decrease monitoring time) is continued after the state is set at time T2, abnormality is notified at time T3. In the experimental example of FIG. 4, the flow decrease monitoring time (time T2 to time T3) is about 15 minutes. However, the flow rate reduction monitoring time may be as short as about two minutes.

Generally, an abnormality such as scale clogging or small dust clogging is gradually progressed (that is, the flow rate is decreased). On the other hand, when the valve disposed in the water passage F is closed, or when a large dust clogging occurs, the flow suddenly stops. In this respect, in the abnormality detection according to the first embodiment, the time from the start of the control of the number of rotations of the compressor 4 to the minimum number of revolutions for the abnormality detection takes about 5 to 10 minutes, Since it is relatively gentle, it is suitable for abnormal detection of flow rate reduction which proceeds gradually.

By this control, the relationship between the outlet hot water temperature and the compressor rotational speed as shown in Fig. 3 (the state in which the normal water circulation amount is secured without clogging in the water pipe) and the outlet hot water temperature It is possible to detect an abnormality in the boiling operation when the relationship of the number of revolutions of the compressor is abnormal (the clogging in the water pipe occurs and the normal water circulation amount can not be ensured). Therefore, it is possible to send out abnormal water circulation without erroneous detection and stop boiling operation.

(Example 2)

The second embodiment relates to a heat pump type hot water heater capable of accurately detecting an abnormality (particularly, a flow stop) occurring in the water passage F '.

5 is a system block diagram of the heat pump type hot water heater according to the second embodiment. FIG. 6 is a control flow chart at the time of operation of the heat pump type hot water heater according to the second embodiment. Fig. 7 shows a temporal change of the compressor temperature in a state in which no abnormality occurs in the water flow path of the heat pump type water heater according to the second embodiment, the outlet refrigerant temperature of the water-refrigerant heat exchanger, and the outlet hot water temperature. 8 shows time changes of the compressor temperature when the abnormality (flow stop) occurs in the water passage of the heat pump type water heater according to the second embodiment, the outlet refrigerant temperature of the water-refrigerant heat exchanger, and the outlet hot water temperature.

The heat pump type hot water heater according to the second embodiment includes a compressor 104 having a variable capacity, a water-refrigerant heat exchanger 105 for heating water by high-temperature, high-pressure refrigerant discharged from the compressor 104, A water temperature detection unit 115 for detecting the temperature of the water heat exchanged in the refrigerant heat exchanger 105, a refrigerant temperature detection unit 116 for detecting the temperature of the refrigerant heat-exchanged in the water-refrigerant heat exchanger 105, And a control unit 120 for controlling the capacity of the battery. The water heat exchanger 105 is connected to the water-refrigerant heat exchanger 105 through a water-refrigerant heat exchanger 105. The water-refrigerant heat exchanger 105 is connected to the water- ).

The heat pump type hot water heater includes a tank 109 for storing hot water heated by the water-refrigerant heat exchanger 105, a tank unit 102 for storing the tank 109, a compressor 104, - a heat pump unit (101) for receiving the refrigerant heat exchanger (105). The water passage F 'is provided across the tank unit 102 and the heat pump unit 101.

Specifically, as shown in Fig. 5, this heat pump type hot water heater includes a heat pump unit 101 in which a refrigeration cycle including the water-refrigerant heat exchanger 105 shown in the left side of the figure is mounted in the casing, And a tank unit 102 in which a hot water supply circuit including a tank 109 shown on the right side of the drawing is mounted inside the casing. The heat pump unit 101 and the tank unit 102 are structured so as to be connected using the connection pipe 103 at the installation place of the heat pump type water heater.

On the other hand, in many cases, hot water is stored in the tank 109, and in this case, the tank 109 may be referred to as a storage tank. Further, the water-refrigerant heat exchanger 105 generally heats water and is sometimes referred to as a water-refrigerant heat exchanger.

The refrigeration cycle includes a compressor 104 for compressing refrigerant, a water-refrigerant heat exchanger 105 for exchanging heat with the water introduced from the tank 109 by high-temperature and high-pressure refrigerant discharged from the compressor 104, A decompression valve 106 in which the refrigerant flowing out of the refrigerant heat exchanger 105 is decompressed and an evaporator 107 in which the low temperature and low pressure refrigerant decompressed by the decompression valve 106 exchanges heat with air, As shown in FIG. The evaporator 107 has a structure in which outside air is ventilated by the fan 108. [ On the other hand, in this refrigeration cycle, carbon dioxide is used as the refrigerant.

The compressor (104) is controlled in capacity by the controller (120) so that the temperature of the hot water heat-exchanged in the water-refrigerant heat exchanger (105) becomes a predetermined target hot water temperature. Specifically, the compressor 104 is an inverter compressor whose capacity is controlled by controlling the number of revolutions of the compressor. However, the present invention is not limited to this. For example, it may be a compressor that performs the capacity control by returning the discharged refrigerant to the suction side. 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 109 for collecting a required amount of hot water, a pump (circulation pump) 110 for introducing water at the bottom of the tank 109, and water discharged from the pump (circulation pump) And the water-refrigerant heat exchanger 105 for heat exchange is annularly connected by a circulation pipe, and the water discharged from the water-refrigerant heat exchanger 105 is returned to the tank 109 have. That is, the water passage 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 in the second embodiment. The bottom of the tank 109 is connected to a water supply source such as water not shown through 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 water heater or a shower is connected to the water supply source.

The compressor 104 is provided with a compressor temperature sensor 113 for measuring the housing temperature of the compressor 104. Accordingly, the temperature (refrigerant discharge temperature) of the refrigerant discharged from the compressor 104 can be detected. On the other hand, the refrigerant discharge temperature may be detected by a temperature sensor provided on the discharge pipe of the refrigerant. However, by detecting the housing temperature of the compressor 104 as the refrigerant discharge temperature, it is possible to suppress the fluctuation of the refrigerant temperature to a lower level and to control the compressor 104 more easily than to detect the temperature of the discharge pipe of the refrigerant .

To detect the temperature of refrigerant flowing out of the water-refrigerant heat exchanger 105, a refrigerant temperature sensor 116 as a refrigerant temperature detecting unit 116 is connected to a refrigerant pipe downstream of the water-refrigerant heat exchanger 105, Respectively. The water-refrigerant heat exchanger (105) is provided at the front and rear of the piping of the water cycle with a water-refrigerant heat exchanger inlet (112) as a water temperature detecting section (114) for detecting the temperature of water flowing into the water- A water temperature sensor and a water-refrigerant heat exchanger outlet hot water temperature sensor serving as a water temperature detecting unit 115 for detecting the temperature of water flowing out from the water-refrigerant heat exchanger 5 are provided.

The heat pump type hot water heater is judged to be abnormal in the water flow path F 'when 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. In this way, it is possible to eliminate the factor of the state of the water passage F 'depending on the installation place, and to detect an abnormality in the water passage F'. The refrigerating cycle including the compressor 104 does not differ greatly in the pressure or the pressure loss of the fluid depending on the installation place of the heat pump type hot water supply device and therefore the abnormality of the water flow path F ' The detection accuracy can be improved.

On the other hand, the reference temperature becomes equal to 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, when the temperature of the water temporarily rises , Overshoot). Taking this into consideration, in this heat pump type hot water heater, the reference temperature is set higher than the target hot water temperature by several degrees Celsius. Accordingly, even when the temperature of the hot water temporarily exceeds the target hot water temperature, it is not immediately judged as abnormal.

In this heat pump type hot 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 has the following advantages: It is suitable to detect abnormality of the flow path F 'with high accuracy. In the general heat pump type hot water heater, the refrigeration cycle in which the tank 109 and the water-refrigerant heat exchanger 105 are housed is composed of different units separated from each other. In this case, the state (piping resistance, etc.) of the water passage F 'differs significantly for each heat pump type hot water heater depending on the shape and length of the connection pipe 103 to be installed at the time of installation and the number of bent portions. In this respect, since this heat pump type hot water heater is controlled based on the capacity of the compressor 104, not on the basis of the flow rate of the water flow path F ', it is possible to perform highly accurate detection .

Specifically, when the temperature of the refrigerant heat-exchanged in the water-refrigerant heat exchanger 105 continues to be equal to or higher than the target hot water temperature for a predetermined time or longer, the heat-pump type hot water heater is heated to an abnormality of the water flow path F ' . In this way, there is no case where the accidental fluctuation of the temperature is judged as abnormal, and the accuracy of the abnormality judgment can be further improved.

The heat pump type water heater determines that the flow of the water flowing through the water passage F 'is stopped when it is judged as abnormal as described above. Then, a notification is issued to the effect that the water flow of the water passage F 'is stopped. Specifically, an error is displayed on a display screen provided on a remote controller or the like.

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

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

Further, the control unit 120 corrects the number of rotations of the compressor 104 so that the outlet hot water temperature (S104 in Fig. 6) and the target hot water temperature are equal to each other (S105 in Fig. 6). With this operation, since the number of revolutions of the compressor that outputs the heating capacity is increased or decreased with respect to the amount of circulating water, the heating capacity currently outputting can be accurately grasped.

In the water-refrigerant heat exchanger (105), heat exchange is carried out by water and a refrigerant when the water circulation amount is secured without clogging or the like during the boiling operation by this operation, 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 the normal water circulation amount can not be ensured, the refrigerant in the water-refrigerant heat exchanger 105 can not be radiated as water to be heated, 8, the outlet refrigerant temperature of the water-refrigerant heat exchanger 105 approaches the boiling target temperature.

In order to detect this phenomenon, in the present embodiment, the outlet refrigerant temperature of the water-refrigerant heat exchanger 105 is always monitored (S106 in FIG. 6) during the boiling operation so that the outlet refrigerant temperature is lower than the boiling target temperature (S107 in FIG.

When the outlet refrigerant temperature is lower than the boiling target temperature (S107 → No in FIG. 6), the opening degree of the pressure reducing valve 106 described above and the number of revolutions of the compressor are corrected. When the outlet refrigerant temperature becomes higher than the boiling target temperature (S7 → Yes in FIG. 6), it is confirmed that the high temperature state is maintained even after a predetermined time (S108 → Yes in FIG. 6) An error is notified (S109 in Fig. 6), and the operation is stopped. On the other hand, the predetermined time may be called a flow stop monitoring time.

Therefore, the circulation of water that boils by clogging of dust in a water pipe or clogging of scale attached to a pipe due to precipitation of a hard component (for example, calcium carbonate) contained in tap water as scale and air shortage due to shortage of air in the pipe It is possible to detect a problem with high accuracy and inexpensively and to respond promptly by an abnormality notification, thereby improving the reliability.

The time change of the compressor rotational speed when the abnormality (flow stop) occurs in the water passage F 'and the outlet refrigerant temperature of the water-refrigerant heat exchanger will be described with reference to the experimental example of Fig. At time T11, when the operation of the compressor 104 is started and there is an abnormality in the water passage F ', the outlet refrigerant temperature gradually rises. At time T12, the outlet refrigerant temperature exceeds the housing temperature of the compressor (104). In the experimental example of Fig. 8, the time from time T11 to time T12 is about 1 to 2 minutes. Then, when it is confirmed that the predetermined time (flow stop monitoring time) or more continues after the state is set at the 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.

Generally, an abnormality such as scale clogging or small dust clogging is gradually progressed (that is, the flow rate is decreased). On the other hand, in the case where the valve disposed in the water passage F 'is closed, or when large dust clogging occurs, the flow suddenly stops. In this regard, the abnormality detection according to the second embodiment is based on the fact that the time from the start of heating in the abnormal state to the time when the outlet hot water temperature exceeds the housing temperature of the compressor 104 is about 1 to 2 minutes, Therefore, it is suitable for abnormal detection of sudden flow stop.

With this control, the relationship between the outlet refrigerant temperature and the outlet hot water temperature of the water-refrigerant heat exchanger 105 shown in Fig. 7 (the state in which the normal water circulation amount is secured without clogging in the water pipe) and , The change in the relationship between the outlet refrigerant temperature and the outlet hot water temperature of the water-refrigerant heat exchanger 105 shown in Fig. 8 (the state in which clogging in the water pipe occurs and the regular water circulation amount can not be ensured) Can be detected during boiling operation. Therefore, it is possible to send out abnormal water circulation without erroneous detection and stop boiling operation. Further, since the determination of the abnormality detection is performed at the boiling target temperature, even if the boiling target temperature is set to any value, the water circulation abnormality can be emitted without erroneous detection and the boiling operation can be stopped.

(Example 3)

Since the heat pump type hot 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. 5, the description of the piping structure and the like is omitted by omitting the same reference numerals.

The third embodiment is a heat pump capable of detecting both an abnormality of the flow rate reduction occurring in the water passage F described in the first embodiment and an abnormality of the flow stoppage occurring in the water passage F ' The present invention relates to a water heater.

That is, in the heat pump type hot water heater according to the third embodiment, when the temperature of the water heat-exchanged in the water-refrigerant heat exchanger 105 is higher than the target hot water temperature while the compressor 104 is operating at the preset reference capacity or less, When the temperature of the refrigerant heat-exchanged in the water-refrigerant heat exchanger 105 is equal to or higher than the target hot water temperature, it is determined that the flow of water in the water passage F ' It is judged that it is stopped.

Since the abnormality detection of the flow rate reduction in the third embodiment is described in the first embodiment and the abnormality detection of the flow stop is described in the second embodiment, the detailed description of the control is omitted.

On the other hand, steps S201 to S205 in Fig. 9 correspond to steps S1 to S5 in the first embodiment and steps S101 to S105 in 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 in the second embodiment. Step S210 corresponds to step S9 of the first embodiment and step S109 of the second embodiment, respectively.

Generally, an abnormality such as scale clogging or small dust clogging gradually proceeds (that is, the flow rate decreases). On the other hand, when the valve disposed in the water passage F 'is closed or an abnormality such as large dust clogging occurs, the flow suddenly stops. In this respect, the abnormality detection in which the temperature of the water heat-exchanged in 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 is required to detect abnormality Since the time is comparatively long, it is suitable for the abnormality detection of the flow rate decrease progressing gradually. On the other hand, in 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 the reference temperature determined based on the target hot water temperature, the time required for the abnormality detection is relatively short, It is suitable for abnormal detection of stopping.

Therefore, according to the heat pump type hot water heater according to the third embodiment, even if any one of the flow reduction or the flow stop occurs, it can be accurately detected. Even if the flow is not stopped but a sudden drop in flow rate occurs (for example, when a medium-sized dust blockage occurs), it is possible to reliably detect have.

On the other hand, the heat pump type hot water heater according to the present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the invention.

For example, although water has been described as an example of the liquid to be heated (liquid to be heated) in the above embodiment, the liquid to be heated (liquid to be heated) is not limited to this, , Storage liquid, etc.). As such a heat pump type hot water heater, for example, a system in which hot liquid heated by a heat pump is stored in a tank, and the hot water is indirectly heated and hot water is supplied by using this high temperature liquid. In this case, the water-refrigerant heat exchanger can be replaced with a liquid-refrigerant heat exchanger, and the hot water temperature and water temperature can be replaced with liquid temperature, and the water flow path can be replaced with a liquid flow path.

In the above embodiment, a heat pump type hot water heater for storing high temperature water heated by a heat pump is described as an example. However, the present invention is applicable to a system in which high temperature water heated by a heat pump is supplied to a hot water tank terminal The present invention is also applicable to a heat pump type hot water heater.

In the above embodiment, a heat pump type hot water heater for introducing and heating water stored in a tank into a water-refrigerant heat exchanger has been described as an example. However, the present invention is not limited to this, The present invention is also applicable to a heat pump type hot water heater of a heating type.

In the above embodiment, the tank unit 2 for storing the tank 9 and the heat pump unit 1 for accommodating the compressor 4 and the liquid-refrigerant heat exchanger 5 are separately provided However, the present invention is not limited to this, and a tank, a compressor, and a liquid-refrigerant heat exchanger may be integrally installed in one unit.

1, 101: Heat pump unit
2, 102: tank unit
3, 103: Connection piping
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 piping
13, 113: Compressor temperature sensor
14, 15, 114, 115: a water temperature detection unit
116: Refrigerant temperature detection unit

Claims (8)

A liquid-refrigerant heat exchanger for heating the liquid to be heated by the high-temperature, high-pressure refrigerant discharged from the compressor, and a liquid temperature detector for detecting the temperature of the liquid to be heat-exchanged in the liquid-refrigerant heat exchanger, And a control unit for controlling the capacity of the compressor,
The liquid-refrigerant heat exchanger according to claim 1, wherein the liquid-refrigerant heat exchanger is a liquid-refrigerant heat exchanger,
The control unit controls the capacity of the compressor so that the temperature of the liquid to be heat-exchanged in the liquid-refrigerant heat exchanger becomes a predetermined target liquid temperature,
Wherein when the temperature of the liquid heat-exchanged in the liquid-refrigerant heat exchanger is higher than the target liquid temperature while the compressor is operating at a preset capacity or less, it is determined that the liquid flow path is abnormal (abnormal) Pump type water heater. The method according to claim 1,
When the state in which 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 operated at a preset capacity or less, Wherein said heat pump type hot water heater is a heat pump type hot water heater. The method according to claim 1,
Wherein the controller controls the capacity of the compressor so that the temperature of the liquid to be heat-exchanged in the liquid-refrigerant heat exchanger becomes the target liquid temperature, and when the compressor is operated at a preset capacity or less, Is notified of a decrease in the flow rate of the liquid to be heated of the liquid flow path when the temperature of the liquid flow path is higher than the target liquid temperature. A liquid-refrigerant heat exchanger for heating the liquid to be heated by the high-temperature, high-pressure refrigerant discharged from the compressor, and a liquid temperature detector for detecting the temperature of the liquid to be heat-exchanged in the liquid-refrigerant heat exchanger, A refrigerant temperature detection unit for detecting the temperature of the refrigerant heat-exchanged in the liquid-refrigerant heat exchanger, and a control unit for controlling the capacity of the compressor,
And a liquid flow path for introducing the liquid to be heated into the liquid-refrigerant heat exchanger and passing through the liquid-refrigerant heat exchanger,
The control unit controls the capacity of the compressor so that the temperature of the liquid to be heat-exchanged in the liquid-refrigerant heat exchanger becomes a predetermined target liquid temperature,
When the temperature of the liquid heat-exchanged in the liquid-refrigerant heat exchanger is higher than the target liquid temperature when the compressor is operating at a preset capacity or less, it is judged that the flow rate of the liquid to be heated flowing through the liquid flow path is decreased and,
Wherein when the temperature of the refrigerant heat-exchanged in the liquid-refrigerant heat exchanger is equal to or higher than a temperature determined based on the target liquid temperature, it is determined that the flow of the liquid to be heated in the liquid flow path is abnormal Water heater. 5. The method according to any one of claims 1 to 4,
A tank for storing the heated liquid heated by the liquid-refrigerant heat exchanger,
A tank unit for containing the tank,
And a heat pump unit for receiving the compressor and the liquid refrigerant heat exchanger,
Wherein the liquid flow path is provided across the tank unit and the heat pump unit. delete delete delete

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