JP2002340401A - Heat pump type hot water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type hot water supplier to improve operation efficiency and effectively utilize hot water capacity of a hot water storage tank. SOLUTION: The heat pump type hot water supplier comprises a means 13 for detecting the condition immediately before completion of boiling-up to detect just before boiling-up of the whole of a hot water storage tank 5; a means 14 for releasing the condition immediately before completion of boiling-up to release detection of right before boiling-up of the whole of the hot water storage tank 5; and a control means 12 to vary the valve opening of a pressure reducing device 3 by means of a signal from the means 13, and thereafter vary the valve opening of the pressure reducing device 3 by means of a signal from the means 14. Since in the case of boiling-up completion approaching and a discharge pressure being increased, the valve opening of the pressure reducing device 3 is varied, hot water supplying/heating operation is practicable to a high hot water supply temperature, thereby effectively utilizing hot water capacity of the hot water storage tank 5. Thereafter, since, when a water supply temperature is reduced due to supply of hot water, the valve opening of the pressure reducing device 3 is varied, hot water supplying/heating operation excellent in efficiency is practicable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply type heat pump water heater.

[0002]

2. Description of the Related Art A conventional heat pump water heater of this kind is disclosed in Japanese Patent Application Laid-Open No. 60-164157. FIG. 13 is a configuration diagram of a conventional heat pump water heater. In FIG. 13, a compressor 1, a refrigerant-to-water heat exchanger 2,
A refrigerant circulation circuit including a decompression device 3 and an evaporator 4 and a hot water supply circuit connecting a hot water storage tank 5, a circulation pump 6, the refrigerant-to-water heat exchanger 2, and an auxiliary heater 7 are discharged from the compressor 1. The high-temperature, high-pressure superheated gas refrigerant flows into the refrigerant-to-water heat exchanger 2, where it heats the water sent from the circulation pump 6. Then, the condensed and liquefied refrigerant is decompressed by the decompression device 3 and flows into the evaporator 4 where it absorbs atmospheric heat to evaporate and return to the compressor 1. On the other hand, the hot water heated by the refrigerant / water heat exchanger 2 flows into the upper portion of the hot water storage tank 5 and is gradually stored from above. Then, when the inlet water temperature of the refrigerant-to-water heat exchanger 2 reaches a set value, the feedwater temperature detecting means 8 detects it, stops the heat pump operation by the compressor 1 and switches to the independent operation of the auxiliary heater 7. Things.

[0003]

However, in the above-described configuration of the prior art, as the boiling operation time elapses, a hot-water mixed layer is formed at a portion where hot water and water in the hot-water storage tank 5 come into contact with each other, and the layer is gradually formed. Expand. FIG. 14 shows the temperature distribution of hot water in hot water storage tank 5. In the figure, T1 is the boiling temperature (high-temperature hot water), and T2 is the city water temperature (low-temperature hot water). The above-mentioned hot-water mixture layer is generated by heat conduction and convection between the high-temperature hot water and the low-temperature hot water, and is transferred from the high-temperature hot water to the low-temperature hot water. To rise. Therefore, when the boiling of the hot water storage tank 5 is nearly completed, the temperature of the feedwater flowing into the refrigerant-to-water heat exchanger 2 increases, so that the discharge pressure of the compressor 1 increases, and the compression pressure such as the motor winding temperature increases. The durability of the machine 1 becomes an issue.

FIG. 15 shows the relationship between the feed pressure of the compressor 1 and the feed water temperature, with the horizontal axis representing the feed water temperature flowing into the refrigerant / water heat exchanger 2 and the vertical axis representing the discharge pressure of the compressor 1 at that time. FIG. The pressure P in the figure is a normal upper limit pressure, and in order to guarantee the durability of the compressor 1, it is necessary to operate the compressor 1 at or below this pressure in normal operation. The supply water temperature at the time of the pressure P is T3 from the figure. Further, the lower limit of the effective hot water temperature is Tu (for example, 45 ° C.), and T3 and Tu
Is shown in FIG. In the cross-sectional view of the hot water storage tank 5 shown on the left side of the figure, a region below the hot water temperature T3 is a region that can be boiled, and a region above Tu is a region that can be used as effective hot water. However, the area between the hot water temperatures T3 and Tu (shaded area) is an area that cannot be used as effective hot water.

As described above, in the configuration of the conventional example, the operation must be stopped in a state where the water temperature flowing through the refrigerant-water heat exchanger 2 is low, so that the lower part of the hot water storage tank 5 is stopped in a state of low-temperature water. As a result, the hot water capacity of the hot water storage tank 5 cannot be used effectively. Therefore, the amount of hot water stored decreases, and the hot water supply load cannot be satisfied. As one method for solving this, it is conceivable to increase the capacity of the hot water storage tank 5. But,
In this case, there is a problem that the installation area of the hot water tank 5 is increased, the degree of freedom of installation is limited, and the cost is increased. Further, as another method, there is a method of increasing the amount of stored hot water by operating the auxiliary heater 7 alone after stopping the heat pump operation. However, in this case, there is a problem that power consumption is increased and efficiency is deteriorated because heating is performed by a heater or the like.

The present invention solves the above-mentioned conventional problems, and stores high-temperature hot water up to the lower portion of a hot water storage tank with low power consumption without an abnormal rise in temperature and abnormal pressure of a compressor.
It is an object of the present invention to provide a heat pump water heater capable of effectively utilizing a hot water capacity.

[0007]

In order to solve the above-mentioned conventional problems, a heat pump water heater according to the present invention comprises: means for detecting immediately before the completion of boiling of the entire hot water storage tank; Means for immediately before completion of boiling, which cancels the detection of immediately before, and a valve opening of the pressure reducing device when the signal from the means for immediately before completion of boiling becomes a predetermined first signal, and thereafter, the boiling And control means for controlling the valve opening of the pressure reducing device to be closed when the signal from the release means immediately before the completion of raising becomes a predetermined second signal. Therefore, when the boiling is near to completion and the discharge pressure of the compressor rises, the valve opening of the pressure reducing device is controlled to be open, and the discharge pressure is kept low. Further, when the supply water temperature becomes low after the hot water supply or the like, the valve opening of the pressure reducing device is controlled so as to be closed, so that the hot water supply heating operation can be performed efficiently.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a refrigerant circulation circuit in which a compressor, a refrigerant-to-water heat exchanger, a decompression device, and an evaporator are sequentially connected, a hot water tank, a circulation pump, and the refrigerant-to-water. A hot water supply circuit in which heat exchangers are sequentially connected, and a water-side inlet of the refrigerant-to-water heat exchanger for keeping a boiling temperature, which is a water-side outlet water temperature of the refrigerant-to-water heat exchanger, constant in the hot water supply circuit. Between the hot water tank, or, flow control means for controlling a flow regulating valve provided between the water side outlet of the refrigerant-to-water heat exchanger and the hot water tank, and immediately before the entire hot water tank boils A detection means for immediately before the completion of boiling, a detection means for immediately before the completion of boiling, and a signal from the detection means for immediately before the completion of boiling to a predetermined first signal. The valve opening of the pressure reducing device And thereafter, a control means for changing the valve opening of the decompression device when the signal from the release means immediately before the completion of the boiling becomes a predetermined second signal, whereby the completion of the boiling is approached, When the discharge pressure of the compressor rises, the valve opening of the pressure reducing device is changed, the discharge pressure is kept low, and the hot water supply heating operation can be performed up to the high feed water temperature, and wasteful areas that cannot be used as effective hot water are more increased. Since the amount of hot water is reduced, the hot water capacity of the hot water storage tank can be used effectively.Furthermore, when the temperature of the water supply becomes low due to hot water supply, the opening degree of the pressure reducing device is controlled to be closed. Good hot water supply heating operation becomes possible.

According to a second aspect of the present invention, since the discharge pressure detecting means is provided as the means for detecting immediately before the completion of boiling and the means for releasing immediately before the completion of boiling, the optimum discharge pressure is controlled by directly controlling the discharge pressure. Since the opening degree of the valve of the pressure reducing device is changed, the durability of the compressor is more reliably improved, and the hot water supply heating operation can be performed efficiently.

According to a third aspect of the present invention, there is provided a hot-water detecting means for detecting that hot water has been discharged from the hot water storage tank and a timer for measuring the hot-water tapping time as means for releasing immediately before completion, and a signal from the means for detecting immediately before boiling is completed. After controlling to open the valve opening of the pressure reducing device, when the tapping detecting means detects a predetermined tapping time, by providing control means for controlling to close the valve opening of the pressure reducing device, The valve opening of the pressure reducing device is changed immediately before the completion of boiling, so that the hot water capacity of the hot water tank can be used effectively and efficient hot water supply heating operation can be performed. When the detection immediately before the completion of boiling is released, the temperature of the water supply drops, so that the valve opening of the pressure reducing device is changed, so that the hot water supply heating operation can be performed efficiently.

According to a fourth aspect of the present invention, there is provided a tapping temperature detecting means for detecting a tapping temperature of the tapping water from the hot water storage tank as the tapping temperature detecting means. Is detected, the temperature of the water supply drops, so that the valve opening of the pressure reducing device is controlled to be closed, so that an efficient hot water supply heating operation can be performed.

According to a fifth aspect of the present invention, there is provided a hot water tank temperature detecting means for detecting a lower temperature of the hot water tank as a means for detecting immediately before the completion of boiling and a means for releasing immediately before the completion of boiling, so that the temperature of the hot water tank can be directly measured. It performs detection and changes the valve opening of the decompression device optimally according to this hot water tank temperature.
This more reliably improves the durability of the compressor, and also enables efficient hot water supply heating operation.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of a heat pump water heater according to Embodiment 1 of the present invention, and FIG. 2 is a detection just before the completion of boiling with respect to the operation time when the heat pump water heater is not released immediately before the completion. FIG. 3 is a graph showing the detection state of the means, the operation state of the compressor, the valve opening degree of the pressure reducing device, the discharge pressure, and the feed water temperature, FIG. 3 is an explanatory diagram showing the temperature distribution of the hot water tank of the heat pump water heater, and FIG. It is a graph which shows the detection state of the detection means just before completion of boiling, the operating state of a compressor, the valve opening degree of a decompression device, the discharge pressure, and the feed water temperature with respect to the operation time when there is a release immediately before completion of heating of a heat pump water heater. . Note that the same components as those in FIG. 13 described in the conventional example are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 1, a flow rate control means 10 controls an opening degree of a flow rate control valve 11 by a signal from a boiling temperature detecting means 9 provided at a water side outlet of the refrigerant-to-water heat exchanger 2,
The outlet water temperature (boiling temperature) of the refrigerant-to-water heat exchanger 2 is raised to be substantially constant. Further, the control means 12
The valve of the pressure reducing device 3 is provided by a signal from the immediately before boiling completion detecting means 13 for detecting immediately before the completion of boiling or a signal from the immediately before completion of boiling completion releasing means 14 for canceling the detection of immediately before the completion of boiling. It controls the opening.
Furthermore, the state storage means 15 stores whether or not the immediately before completion of boiling detection means 13 has detected immediately before the completion of boiling, and 16 is a water supply pipe.

As the means 13 for detecting immediately before the completion of boiling and the releasing means 14 for immediately before the completion of boiling, here, a feedwater temperature detecting means 8 for detecting a feedwater temperature which is a water-side inlet water temperature of the refrigerant / water heat exchanger 2 is used. Used. In addition, the flow control valve 1
1 includes an electric valve (not shown) driven by a stepping motor, and the pressure reducing device 3 includes an electric expansion valve (not shown).

Next, the operation and operation will be described. First,
A case where there is no cancellation immediately before the completion of boiling will be described. FIG. 2 shows the operation time on the horizontal axis, the detection state of the detection unit 13 immediately before completion of boiling, the operation state of the compressor 1, the valve opening degree of the pressure reducing device 3, the discharge pressure, and the feed water temperature on the vertical axis. 3 shows the relationship between the operating state, the state of detection by the detecting means 13 immediately before completion of boiling, the operating state of the compressor 1, the valve opening of the pressure reducing device 3, the discharge pressure, and the supply water temperature. As described in the conventional example, when the boiling of the hot water storage tank 5 is nearly completed, the temperature of the supply water flowing into the refrigerant-to-water heat exchanger 2 increases. That is,
When the water flowing into the refrigerant-to-water heat exchanger 2 becomes the portion of the hot-water mixture layer described above, the supply water temperature increases with the operation time, as shown in FIG. Then, the feedwater temperature detecting means 8 which is the detecting means 13 immediately before the completion of the boiling is turned on (the boiling temperature T1).
Lower than the temperature) is the detected temperature Th immediately before the completion of boiling.
Is detected, the control means 12 increases (opens) the valve opening of the pressure reducing device 3 and, based on the signal from the control means 12, the state storage means 15 causes the detection means 1 to detect immediately before the completion of boiling.
No. 3 is stored just before the completion of boiling. At this time, the discharge pressure decreases from P1 to P2. Thereafter, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. Then, the water supply temperature detecting means 8
However, when the supply water temperature T3a at which the service upper limit pressure P is reached is detected, the compressor is stopped, and the hot water supply heating operation ends. In addition,
The thick dotted line in the figure is the case of the conventional example in which the valve opening of the pressure reducing device 3 is not controlled. It can be seen that the water supply temperature at the operation limit increases from T3 to T3a, and the operation range increases. FIG. 3 shows a temperature distribution of hot water in hot water storage tank 5. In the cross-sectional view of the hot water storage tank 5 shown on the left side of the drawing, a region below the hot water temperature T3a is a region where boiling can be performed, and a region above Tu is a region that can be used as effective hot water. The area that cannot be used as an effective hot water is the area between the hot water temperatures T3 and Tu in the case of the conventional example shown in FIG. 14, but in the present embodiment, the area between the hot water temperatures T3a and Tu (the hatched area). Part). In other words, the area between the hot water temperatures T3 and T3a (the shaded area indicated by the dotted line) is the hot water area that has become effective according to the present embodiment.

Next, a case where there is release immediately before completion of boiling will be described. 4, similarly to FIG. 2, the horizontal axis represents the operation time, and the vertical axis represents the detection state of the detection means 13 immediately before the completion of boiling, the operation state of the compressor 1, the valve opening degree of the pressure reducing device 3, and the discharge pressure. It shows the relationship between the operating state of the compressor 1, the operating state of the compressor 1, the valve opening degree of the pressure reducing device 3, the discharge pressure, and the operating temperature of the feed water by taking the feed water temperature. . As in the case described above, when the feed water temperature detecting means 8 as the detecting means 13 immediately before the completion of boiling detects the detected temperature Th immediately before the completion of boiling, the control means 12 increases the valve opening of the pressure reducing device 3 (opens). At the same time, the state storage means 15 stores the fact that the detection means 13 immediately before the completion of boiling has detected immediately before the completion of the boiling by a signal from the control means 12. At this time, the discharge pressure decreases from P1 to P2. Then, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. afterwards,
At the operation time t, when hot water is discharged from the hot water storage tank 5 and cold water flows into the hot water storage tank 5 from the water supply pipe 16, the water supply temperature detected by the water supply temperature detecting means 8 also decreases. When the supply water temperature finally reaches the release temperature Tr immediately before the completion of boiling, the control means 12 detects the contents of the state storage means 15. Then, if the contents of the state storage means 15 store that the state immediately before the completion of boiling is detected,
Is reduced (closed), and the state storage means 15 cancels the storage in which the detection unit 13 immediately before the completion of boiling has detected the state immediately before the completion of the boiling (if the contents of the state storage means 15 are the boiling state). The control of the valve opening of the pressure reducing device 3 is not performed unless the fact that the detection immediately before the completion of the raising is detected is stored.)

Thereafter, as the operation time elapses, the feedwater temperature further rises, and when the feedwater temperature detecting means 8, which is the detecting means 13 immediately before the completion of the boiling, detects the detected temperature Th immediately before the completion of the boiling again, the control means 12 starts the operation. , Again, the decompression device 3
Is increased, and the signal from the control means 12 causes the state storage means 15 to store the fact that the detection means 13 just before the completion of boiling has detected immediately before the completion of boiling.
Thereafter, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. Then, when the feedwater temperature detecting means 8 detects the feedwater temperature T3a, the compressor is stopped and the hot water heating operation is terminated.

As described above, in this embodiment, the means 13 for detecting immediately before the completion of boiling of the entire hot water tank 5 and the completion of boiling for canceling the detection of immediately before the entire hot water tank 5 is heated are described. Immediately before release means 14,
The valve opening of the pressure reducing device 3 is opened when the signal from the detecting means 13 immediately before the completion of boiling becomes a predetermined first signal, and then the signal from the releasing means 14 immediately before the completion of boiling is a predetermined second signal. And the control means 12 for controlling the valve opening of the pressure reducing device 3 to be closed when the pressure of the compressor 1 is reduced. The opening degree is controlled to be open, the discharge pressure is kept low, the hot water supply heating operation can be performed up to the high supply water temperature, and the hot water capacity of the hot water storage tank 5 can be used effectively. If it goes low,
Since the opening degree of the valve of the pressure reducing device 3 is controlled to be closed, an efficient hot water supply heating operation can be performed.

In this embodiment, the circulation pump 6 is provided between the water-side inlet of the refrigerant / water heat exchanger 2 and the hot water storage tank 5, and the flow control valve 11 is provided with the circulation pump 6 and the refrigerant / water heat exchanger. 2 is provided between the inlet of the circulating pump 6 and the hot water storage tank 5, but the position of the flow control valve 11 may be provided between the water-side outlet of the refrigerant and the water heat exchanger 2. The same operation and effect as those in the embodiment of FIG.

As described in the conventional example of FIG. 13, the refrigeration cycle may be a normal heat pump cycle in which the refrigerant-to-water heat exchanger 2 is used as a condenser and the discharge pressure is lower than a critical point. However, a supercritical heat pump cycle in which the refrigerant-to-water heat exchanger 2 is used as a gas cooler and the discharge pressure is higher than the critical point may be used.

(Embodiment 2) FIG. 5 is a block diagram of a heat pump water heater according to Embodiment 2 of the present invention, and FIG. 6 is a diagram showing a detection state of a means for detecting immediately before completion of boiling and an operation of a compressor with respect to an operation time of the heat pump water heater. It is a graph which shows a state, the valve opening degree of a decompression device, and discharge pressure.

This embodiment is different from the first embodiment in that a discharge pressure detecting means 17 for detecting the discharge pressure of the compressor 1 is provided as a means 13 for detecting immediately before completion of boiling and a means 14 for releasing immediately before completion of boiling. It is a configuration. Note that the portions denoted by the same reference numerals as those in the first embodiment have the same configuration, and description thereof will be omitted.

Next, the operation and operation will be described. FIG.
Takes the operation time on the horizontal axis, the detection state of the detection means 13 immediately before completion of boiling, the operation state of the compressor 1, the valve opening degree of the pressure reducing device 3 and the discharge pressure on the vertical axis, and calculates the boiling time with respect to the operation time. 3 shows a relationship between a detection state of the immediately before completion of the raising operation, a detection state of the compressor 1, an operation state of the compressor 1, a valve opening of the pressure reducing device 3, and a discharge pressure. As described in the first embodiment, when the water flowing into the refrigerant-to-water heat exchanger 2 becomes a part of the hot and cold water mixing layer, the supply water temperature rises with the operation time, and accordingly, as shown in FIG. Also rises. When the discharge pressure detecting means 17 which is the detecting means 13 immediately before the completion of the boiling detects the detected pressure Ph immediately before the completion of the boiling, the controlling means 12
Is used to increase (open) the valve opening degree of the pressure reducing device 3 and, based on a signal from the control means 12, the state storage means 15
The fact that the immediately before the completion of boiling is detected by the detecting means 13 is stored. At this time, the discharge pressure decreases. Then, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. Thereafter, the operating time t, the cold water with the hot water from the hot water tank 5 when flowing into the hot water storage tank 5 from the water supply pipe 16, the discharge pressure of the discharge pressure detecting means 17 detects also decreases. And
When the discharge pressure finally reaches the release pressure Pr immediately before the completion of boiling, the control means 12 detects the contents of the state storage means 15. If the contents of the state storage means 15 store that the immediately preceding completion of the boiling is detected, the valve opening of the pressure reducing device 3 is reduced (closed), and the state storage means 15 stores The memory that immediately before the completion of the boiling is detected by the immediately preceding detection means 13 is released (if the contents of the state storage means 15 do not store the fact that the immediately before the completion of the boiling is detected, the valve of the pressure reducing device 3 is opened. Do not control the degree). Thereafter, as the operation time elapses, the feed pressure further increases as the feedwater temperature further increases. Then, the discharge pressure detecting means 1 which is the detecting means 13 immediately before the completion of boiling
7 again detects the detected pressure Ph immediately before the completion of boiling, the control means 12 increases the valve opening of the pressure reducing device 3 again, and the state storage means 15 The fact that the immediately before the completion of the heating is detected by the detection means 13 is stored. Thereafter, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. Then, the discharge pressure detecting means 17
However, when the service upper limit pressure P is detected, the compressor is stopped, and the hot water supply heating operation ends.

As described above, in the present embodiment, the discharge pressure detecting means is provided as the means for detecting immediately before the completion of boiling and the means for releasing immediately before the completion of boiling. Rises,
The opening degree of the pressure reducing device 3 is controlled to be open, the discharge pressure is kept low, the hot water supply heating operation can be performed up to a high supply water temperature, and the hot water capacity of the hot water storage tank 5 can be used effectively.
Thereafter, when the supply water temperature becomes low due to hot water supply or the like, the opening degree of the pressure reducing device 3 is controlled to be closed, so that an efficient hot water supply heating operation becomes possible. In addition, since the control is directly performed by the discharge pressure, the durability of the compressor 1 is more reliably improved.

(Embodiment 3) FIG. 7 is a block diagram of a heat pump water heater according to a third embodiment of the present invention. FIG. It is a graph which shows the valve opening degree of a decompression device, discharge pressure, and feed water temperature.

This embodiment is different from the first embodiment in that hot water detection means 18 for detecting that hot water has been supplied from the hot water storage tank 5 and for detecting that the hot water has been supplied is detected as the release means 14 immediately before the completion of boiling. And a timer 19 for measuring the time during which the operation is performed.
In addition, as the hot water detecting means 18, a flow detecting means 20 for detecting whether or not the hot water flows out is used here. The same reference numerals as in the first embodiment have the same configuration,
Description is omitted.

Next, the operation and operation will be described. FIG.
Takes the operating time on the horizontal axis, the detection state of the detection means 13 immediately before the completion of boiling, the presence or absence of hot water, the valve opening degree of the pressure reducing device 3, the discharge pressure, and the supply water temperature on the vertical axis, and calculates the boiling time with respect to the operating time. 3 shows a relationship between a detection state of the immediately before completion of the raising, a detection state of hot water, presence / absence of tapping, a valve opening degree of the pressure reducing device 3, a discharge pressure, and a water supply temperature. When the boiling of the hot water storage tank 5 is nearly completed, as described in the first embodiment, the supply water temperature rises with the operation time, and accordingly, the discharge pressure also rises as shown in FIG. Then, the detection means 1 immediately before the completion of boiling
When the feed water temperature detecting means 8 detects the detected temperature Th immediately before the completion of boiling, the control means 12 increases (opens) the valve opening of the pressure reducing device 3 and stores the state by a signal from the control means 12. The means 15 stores that the immediately before boiling completion detecting means 13 has detected immediately before the completion of boiling. At this time, the discharge pressure decreases. Then, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. Thereafter, when the hot water is discharged from the hot water storage tank 5 at the operation time t, the flow detecting means 20 as the hot water detecting means 18 detects the flow of the hot water, and the timer 19 measures the time of the hot water. When the time measured by the timer 19 reaches a predetermined tapping time to, the control means 12
Detects the contents of the state storage means 15. If the contents of the state storage means 15 store that the immediately preceding completion of the boiling is detected, the valve opening of the pressure reducing device 3 is reduced (closed), and the state storage means 15 stores The storage that the immediately preceding detection means 13 has detected immediately before the completion of the boiling is canceled (if the contents of the state storage means 15 do not store the fact that the immediately before the completion of the boiling was detected, the valve of the pressure reducing device 3 is removed. The opening is not controlled).

As described above, in this embodiment, the water supply temperature detecting means 8 is provided as the means for detecting immediately before the completion of boiling, and the flow detecting means 20 is provided as the means for releasing immediately before the completion of boiling.
And the timer 19, when the boiling is almost completed and the discharge pressure of the compressor 1 rises, the valve opening of the pressure reducing device 3 is controlled to be opened, the discharge pressure is kept low, The hot water supply heating operation can be performed up to the water supply temperature, and the hot water capacity of the hot water storage tank 5 can be used effectively. Thereafter, when the hot water for a predetermined time is detected, the pressure reducing device 3
Is controlled so as to close the valve opening degree, so that the hot water supply heating operation can be performed efficiently. In addition, since the presence or absence of the flow of the hot water is detected and controlled, a more reliable operation is possible.

(Embodiment 4) FIG. 9 is a block diagram of a heat pump water heater according to a fourth embodiment of the present invention, and FIG. 10 is a diagram showing the detection state, tapping temperature, and depressurization of the heat pump water heater with respect to the operation time of the heat pump water heater. It is a graph which shows the valve opening degree of a device, discharge pressure, and feed water temperature. The present embodiment is different from the third embodiment in that a tapping temperature detecting unit 21 for detecting the temperature of hot water discharged from the hot water storage tank 5 is provided as the tapping detecting unit 18. Note that the portions denoted by the same reference numerals as in the third embodiment have the same configuration, and description thereof will be omitted.

Next, the operation and operation will be described. FIG.
Takes the operating time on the horizontal axis, and the vertical axis shows the detected state of the heating means 13 immediately before the completion of boiling, the tapping temperature, the valve opening degree of the pressure reducing device 3, the discharge pressure, and the supply water temperature, and calculates the boiling time with respect to the operating time. It shows the relationship between the detection state of the immediately before completion detecting means 13, the tap water temperature, the valve opening of the pressure reducing device 3, the discharge pressure, and the water supply temperature. As described in the third embodiment, when the water flowing into the refrigerant-to-water heat exchanger 2 becomes the portion of the hot and cold water mixing layer, the feedwater temperature rises with the operation time, and accordingly, as shown in FIG. Also rises. Then, when the feed water temperature detecting means 8 as the detecting means 13 immediately before the completion of the boiling detects the detected temperature Th immediately before the completion of the boiling, the controlling means 12
Is used to increase (open) the valve opening degree of the pressure reducing device 3 and, based on a signal from the control means 12, the state storage means 15
The fact that the immediately before the completion of boiling is detected by the detecting means 13 is stored. Then, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. Now, when the hot water is discharged from the hot water storage tank 5 at the operation time t, the hot water temperature detecting means 2 serving as the hot water detecting means 18.
1 detects hot water by detecting a temperature equal to or higher than the hot water reference temperature To. Then, the timer 19 measures the time of tapping. When the time measured by the timer 19 reaches a predetermined tapping time to, the control means 12 detects the contents of the state storage means 15. Then, the state storage means 15
If the contents of (1) store the detection immediately before the completion of boiling, the valve opening of the pressure reducing device 3 is reduced (closed).
At the same time, the state storage means 15 cancels the storage that the immediately before boiling completion detecting means 13 has detected immediately before the completion of boiling (if the contents of the state storage means 15 have detected immediately before the completion of boiling). If not, the control of the valve opening of the pressure reducing device 3 is not performed).

As described above, in this embodiment, the water supply temperature detecting means 8 is provided as the means for detecting immediately before the completion of boiling, and the tap water temperature detecting means 21 and the timer 19 are provided as the means for releasing immediately before the completion of boiling. When the discharge pressure of the compressor 1 approaches the completion of boiling and the discharge pressure of the compressor 1 rises, the valve opening of the pressure reducing device 3 is controlled to be opened, the discharge pressure is kept low, and the hot water supply heating operation to a high supply water temperature becomes possible. In addition, the hot water capacity of the hot water storage tank 5 can be effectively used.
Thereafter, when the hot water is detected for a predetermined time, the valve opening of the pressure reducing device 3 is controlled to be closed, so that the hot water supply heating operation can be performed efficiently. Further, since the tapping temperature is directly detected and controlled, more reliable operation is possible.

(Embodiment 5) FIG. 11 is a block diagram of a heat pump water heater according to a fifth embodiment of the present invention, and FIG. 12 is a diagram showing detection of the heat pump water heater immediately before the completion of boiling with respect to the operation time when there is a release immediately before the completion of the heating. It is a graph which shows the detection state of a means, the operation state of a compressor, the valve opening degree of a decompression device, discharge pressure, and the lower temperature of a hot water tank. The present embodiment is different from the first embodiment in that a hot water tank temperature detecting means 22 for detecting a lower temperature of the hot water tank 5 is provided as a means 13 for immediately before completion of boiling and a releasing means 14 for immediately before completion of heating. It is that you are. Note that the portions denoted by the same reference numerals as those in the first embodiment have the same configuration, and description thereof will be omitted.

Next, the operation and operation will be described. A case where there is a release immediately before completion of boiling will be described. FIG.
Is the operating time on the horizontal axis, and the vertical axis shows the detection state of the detection means 13 immediately before completion of boiling, the operation state of the compressor 1, the valve opening degree of the pressure reducing device 3, the discharge pressure, and the lower temperature of the hot water tank 5. Thus, it shows the relationship between the operation time, the detection state of the detection means 13 immediately before completion of boiling, the operation state of the compressor 1, the valve opening of the pressure reducing device 3, the discharge pressure, and the lower temperature of the hot water tank 5. . When the hot water tank temperature detecting means 22 as the detecting means 13 immediately before the completion of the boiling detects the detected temperature Th immediately before the completion of the boiling, the control means 12 increases (opens) the valve opening degree of the pressure reducing device 3 and simultaneously controls the control means 12. , The state storage means 15 stores that the immediately before the completion of boiling is detected by the state detecting means 13. At this time, the discharge pressure decreases from P1 to P2. Then, as the operation time elapses, the lower temperature of the hot water tank further rises, and the discharge pressure rises accordingly. Thereafter, when the hot water is discharged from the hot water storage tank 5 and the cold water flows into the hot water storage tank 5 from the water supply pipe 16 at the operation time t, the hot water tank temperature detecting means 2
2 also lowers the lower temperature of the hot water tank. Then, finally, the lower temperature of the hot water storage tank rises immediately before completion of the release temperature Tr.
Then, the control means 12 detects the contents of the state storage means 15. If the contents of the state storage means 15 store that the immediately preceding completion of the boiling is detected, the valve opening of the pressure reducing device 3 is reduced (closed), and the state storage means 15 stores The memory that immediately before the completion of the boiling is detected by the immediately preceding detection means 13 is released (if the contents of the state storage means 15 do not store the fact that the immediately before the completion of the boiling is detected, the valve of the pressure reducing device 3 is opened. Do not control the degree). Thereafter, as the operating time elapses, the lower temperature of the hot water tank further rises, and when the hot water tank temperature detecting means 22 as the detecting means 13 immediately before the completion of boiling again detects the detected temperature Th immediately before the completion of boiling, the control means 12 Again,
The valve opening of the pressure reducing device 3 is increased, and the control means 1
In response to the signal from 2, the state storage means 15 stores that the detection means 13 immediately before the completion of boiling has detected immediately before the completion of boiling. Thereafter, as the operation time elapses, the lower temperature of the hot water tank further rises, and the discharge pressure rises accordingly. Then, when the hot water tank temperature detecting means 22 detects the lower temperature T3a of the hot water tank, the compressor is stopped and the hot water supply heating operation ends.

As described above, in the present embodiment, the hot water tank temperature detecting means 22 for detecting the lower temperature of the hot water tank 5 is provided as the means for detecting immediately before the completion of boiling and the means for releasing immediately before the completion of boiling. When the discharge pressure of the compressor 1 rises near the completion of the raising, the valve opening of the pressure reducing device 3 is controlled to be opened, the discharge pressure is kept low, and the hot water supply heating operation can be performed up to a high supply water temperature. The hot water capacity of the tank 5 can be used effectively. Thereafter, when the supply water temperature becomes low due to hot water supply or the like, the valve opening of the pressure reducing device 3 is controlled to be closed, so that an efficient supply water heating operation can be performed. Further, since the temperature is directly controlled by the lower temperature of the hot water storage tank 1, the durability of the compressor 1 is more reliably improved.

[0037]

As described above, according to the first to fifth aspects of the present invention, the valve opening degree of the pressure reducing device is changed when the discharge pressure of the compressor approaches when the boiling is completed and the discharge pressure of the compressor increases. In addition, since the discharge pressure is kept low and the hot water supply heating operation can be performed up to a high supply water temperature, a wasteful area that cannot be used as effective hot water is reduced, and the hot water capacity of the hot water storage tank can be effectively used. As a result, a hot water tank of the same size as the conventional one can satisfy a larger hot water supply load, and conversely, to satisfy a hot water supply load of the same size as the conventional one, a smaller hot water tank can be used. The degree is large and the cost is reduced. Furthermore, an efficient hot water supply heating operation can be performed. After that, when the water supply temperature decreases due to hot water, etc.,
Since the valve opening of the pressure reducing device 3 is changed, an efficient hot water supply heating operation can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a heat pump water heater according to a first embodiment of the present invention.

FIG. 2 shows the detection state of the detection means immediately before the completion of boiling, the operating state of the compressor, the operating state of the compressor, the valve opening degree of the pressure reducing device, the discharge pressure, the feed water temperature, and the operation time when the heat pump water heater does not release immediately before the completion of boiling. Graph showing

FIG. 3 is an explanatory diagram showing a temperature distribution of a hot water storage tank of the heat pump water heater.

FIG. 4 shows the detection state of the detection unit immediately before the completion of boiling, the operating state of the compressor, the valve opening degree of the pressure reducing device, the discharge pressure, the feed water temperature, and the operation time when the heat pump water heater has a release immediately before the completion of boiling. Graph showing

FIG. 5 is a configuration diagram illustrating a heat pump water heater according to a second embodiment of the present invention.

FIG. 6 is a graph showing a detection state of a detection unit immediately before completion of boiling, a compressor operation state, a valve opening degree of a pressure reducing device, and a discharge pressure with respect to an operation time of the heat pump water heater.

FIG. 7 is a configuration diagram illustrating a heat pump water heater according to a third embodiment of the present invention.

FIG. 8 is a graph showing a detection state of a detection unit immediately before completion of boiling, a presence or absence of hot water, a valve opening degree of a pressure reducing device, a discharge pressure, and a water supply temperature with respect to an operation time of the heat pump water heater.

FIG. 9 is a configuration diagram illustrating a heat pump water heater according to a fourth embodiment of the present invention.

FIG. 10 is a graph showing a detection state of a detecting means immediately before completion of boiling, a tapping temperature, a valve opening degree of a pressure reducing device, a discharge pressure, and a feedwater temperature with respect to an operation time of the heat pump water heater.

FIG. 11 is a configuration diagram illustrating a heat pump water heater according to a fifth embodiment of the present invention.

FIG. 12 shows a detection state of the means for detecting immediately before completion of boiling, a compressor operation state, an operation state of the compressor, a valve opening degree of the pressure reducing device, a discharge pressure, and a temperature of the hot water tank when the heat pump water heater has a release immediately before completion of boiling. Graph showing lower temperature

FIG. 13 is a configuration diagram showing a conventional heat pump water heater.

FIG. 14 is an explanatory diagram showing a temperature distribution of a hot water tank of the heat pump water heater.

FIG. 15 is a graph showing discharge pressure with respect to feed water temperature of the heat pump water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Refrigerant-water heat exchanger 3 Decompression device 4 Evaporator 5 Hot water storage tank 6 Circulation pump 10 Flow control means 11 Flow control valve 12 Control means 13 Detecting means immediately before completion of boiling 14 Release means immediately before completion of boiling

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Matsumoto 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A refrigerant circulation circuit in which a compressor, a refrigerant-to-water heat exchanger, a pressure reducing device for controlling a flow rate of a refrigerant, and an evaporator are sequentially connected, a hot water tank, a circulation pump, and the refrigerant-to-water heat exchanger are sequentially arranged. A connected hot water supply circuit, and a water-side inlet of the refrigerant-to-water heat exchanger and the hot water storage tank in order to make a boiling temperature that is a water-side outlet water temperature of the refrigerant-to-water heat exchanger in the hot water supply circuit constant. A flow control means for controlling a flow regulating valve provided between the water-side outlet of the refrigerant-to-water heat exchanger and the hot water storage tank, and a boiler for detecting immediately before the entire hot water storage tank is boiled. Immediately before completion detection means, immediately before completion of the boiling water storage tank, and immediately before the completion of boiling, and when the signal from the immediately before boiling completion detection means becomes a predetermined first signal, Change the valve opening of the pressure reducing device, and And a control means for changing a valve opening of the pressure reducing device when a signal from the release means immediately before the completion of boiling becomes a predetermined second signal. 2. The heat pump water heater according to claim 1, further comprising discharge pressure detecting means as means for detecting immediately before completion of boiling and means for canceling immediately before completion of boiling. 3. A dewatering device comprising a tapping detector for detecting tapping from a hot water storage tank and a timer for measuring tapping time, wherein the valve of the pressure reducing device is opened by a signal from the detecting unit immediately before boiling. After changing the degree, when the tapping detecting means detects a predetermined tapping time, the control unit changes the valve opening of the pressure reducing device so as to close the valve opening of the pressure reducing device. The heat pump water heater according to claim 1, characterized in that: 4. The heat pump water heater according to claim 3, further comprising a tapping temperature detecting means for detecting a tapping temperature of the tapping water from the hot water tank as the tapping detection means. 5. A hot water tank temperature detecting means for detecting a lower temperature of the hot water tank as a means for detecting immediately before the completion of boiling and a means for releasing immediately before the completion of boiling.
The heat pump water heater as described.