JP2002286288A - Heat pump hot-water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump hot-water supplier, contriving the improvement of an operating efficiency and the effective utilization of a hot-water volume in a hot-water storage tank. SOLUTION: The heat pump hot-water supplier is provided with a flow rate control means 10 for controlling the flow rate of a circulation pump 6 to make water temperature in the water side outlet port of a heat exchanger between refrigerant and water 2 or a heat-up temperature constant, an immediately before finishing of heat-up detecting means 12 for detecting the immediately before the condition of heat-up of the whole of hot-water storage tank 5 and a control means 11 for controlling the degree of opening of the valve of a pressure reducing device 3 when a signal from the detecting means 12 has become a predetermined signal. When the heating is approached to the finish of heat-up and the discharging pressure of a compressor 1 is increased, the valve of the pressure reducing device 3 is controlled so as to be opened whereby hot-water heating operation can be effected until a feed water temperature is raised to a high temperature thereby permitting the effective utilization of hot-water volume in the hot-water storage tank 5 and, further, permitting efficient supplying hot-water heating operation.

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. 20 is a configuration diagram of a conventional heat pump water heater. In FIG. 20, 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 in which a hot water tank 5, a circulation pump 6, the refrigerant / water heat exchanger 2, and an auxiliary heater 7 are connected, 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 and condenses the water sent from the circulation pump 6.

[0003] The condensed and liquefied refrigerant is depressurized 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. And
When the inlet water temperature of the refrigerant-to-water heat exchanger 2 reaches a set value, this is detected by the feedwater temperature detecting means 8 and the compressor 1
Is stopped, and the operation of the auxiliary heater 7 is switched to the independent operation.

[0004]

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. 21 shows a 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, as 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 winding of the motor The durability of the compressor 1 such as a rise in temperature becomes an issue.

In FIG. 22, the horizontal axis shows the temperature of the feedwater flowing into the refrigerant / water heat exchanger 2, and the vertical axis shows the discharge pressure of the compressor 1 at that time. It shows the relationship. 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. Pressure P
The supply water temperature at the time is T3 from the figure.

The lower limit of the effective hot water temperature is Tu (for example, 45
#C), and the aforementioned T3 and Tu are 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 conventional configuration, the operation must be stopped in a state where the temperature of the water flowing through the refrigerant / water heat exchanger 2 is low, so that the lower part of the hot water storage tank 5 is 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.

However, in this case, there is a problem that the installation area of the hot water storage tank 5 becomes large, the degree of freedom of installation is limited, and the cost becomes high. 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 or abnormal pressure of a compressor.
An object of the present invention is to provide a heat pump water heater in which the capacity of hot water can be effectively used.

[0011]

In order to solve the above-mentioned conventional problems, a heat pump water heater according to the present invention is provided with a means for detecting immediately before the completion of boiling of the entire hot water storage tank, and a means for immediately before the completion of boiling. Control means for controlling the opening degree of the pressure reducing device to be opened when it is detected. Therefore, when the completion of boiling is approached and the discharge pressure of the compressor rises, the opening of the pressure reducing device is controlled to be opened, and the discharge pressure is kept low, so that the hot water supply heating operation can be performed up to a high water supply temperature. Things.

[0012]

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 to which heat exchangers are sequentially connected, a heating completion detecting means for detecting immediately before the entire hot water tank is heated, and a pressure reducing device when a signal from the heating completion detecting means becomes a predetermined signal. And control means for controlling the opening of the pressure reducing device to control the opening of the valve of the pressure reducing device in the case where the boiling is completed and the discharge pressure of the compressor increases. And 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 can be effectively used.

According to a second aspect of the present invention, a control means for determining a change width of the valve opening of the pressure reducing device in accordance with an outside air temperature obtained from an outside air temperature detecting means for detecting an outside air temperature is provided. Since the valve opening of the decompression device is changed optimally according to the temperature, the hot water capacity of the hot water tank can be used effectively, and
An efficient hot water supply heating operation can be performed.

According to a third aspect of the present invention, there is provided a control device for changing a valve opening of the pressure reducing device for each of a plurality of predetermined water supply temperatures, so that an optimum pressure reducing device according to the water supply temperature is provided. Since the valve opening degree is changed, wasteful areas that cannot be used as effective hot water are reduced, so that the hot water capacity of the hot water storage tank can be effectively used, and an efficient hot water supply heating operation can be performed.

According to a fourth aspect of the present invention, there is provided a control means for increasing the change width of the valve opening of the pressure reducing device as the temperature of the water supply increases, so that the pressure reducing device is operated at a high temperature of the water supply where the rise of the discharge pressure is large. Since the discharge pressure is greatly reduced by increasing the amount of change in the valve opening and the valve opening of the decompression device is optimally changed in accordance with the supply water temperature, the hot water capacity of the hot water storage tank can be used effectively and the efficiency can be improved. A good hot water heating operation can be performed.

According to a fifth aspect of the present invention, a control means for changing the valve opening of the pressure reducing device at predetermined time intervals is provided, so that the valve opening of the pressure reducing device is optimized just before the completion of boiling. Since the degree is changed, the hot water capacity of the hot water storage tank can be effectively used, and an efficient hot water supply heating operation can be performed.

According to a sixth aspect of the present invention, a control means for reducing the time interval for changing the valve opening of the pressure reducing device as the boiling is completed is provided, so that the discharge pressure is reduced as the boiling is completed. When the rise is large, the change in the valve opening of the pressure reducing device is increased to greatly reduce the discharge pressure, and the optimal valve opening of the pressure reducing device is changed. A good hot water supply heating operation is possible.

According to a seventh aspect of the present invention, as the detecting means immediately before the completion of the boiling, the time measuring means for measuring the time when the circulation pump reaches the maximum flow rate when the flow rate of the circulation pump reaches the maximum flow rate is provided. Detects that the capacity of the circulating pump has reached a maximum for a predetermined time, changes the valve opening of the pressure reducing device, keeps the discharge pressure low, and continues the heating operation. The hot water supply heating operation becomes possible, and the hot water capacity of the hot water storage tank can be used effectively.

According to an eighth aspect of the present invention, a discharge pressure detecting means is used as a means for detecting immediately before the completion of boiling, and when the detected discharge pressure reaches a set reference pressure, the valve opening of the pressure reducing device is opened. By having control means to control,
Since the hot water capacity of the hot water storage tank can be effectively used and the pressure is directly controlled by the discharge pressure, it is possible to more reliably improve the durability of the compressor.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same components as those described in the related art shown in FIG. 20 are denoted by the same reference numerals, detailed description thereof will be omitted, and different portions will be mainly described.

(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 diagram showing an operation state of a compressor and a valve opening degree of a pressure reducing device with respect to an operation time of the heat pump water heater. Explanatory diagram showing the discharge pressure and feed water temperature,
FIG. 3 is an explanatory diagram showing a temperature distribution of a hot water storage tank of the heat pump water heater.

In FIG. 1, a flow rate control means 10 controls a rotation speed of a circulating pump 6 by a signal from a boiling temperature detecting means 9 provided at a water-side outlet of the refrigerant-to-water heat exchanger 2 to control the refrigerant to water. The outlet water temperature (boiling temperature) of the heat exchanger 2 is raised so as to be substantially constant. In addition, the control means 11 detects immediately before the completion of the boiling.
The signal from 2 controls the valve opening of the pressure reducing device 3.

As the means for detecting immediately before the completion of boiling, for example, a feedwater temperature detecting means 8 for detecting a feedwater temperature which is a water-side inlet water temperature of the refrigerant-to-water heat exchanger 2 is used as an example. The pressure reducing device 3 includes an electric expansion valve (not shown) and the like.

Next, the operation and operation of the above embodiment will be described. FIG. 2 shows the operating time on the horizontal axis, the operating state of the compressor, the valve opening degree of the pressure reducing device, the discharge pressure, and the feedwater temperature on the vertical axis, and shows the operating state of the compressor and the valve of the pressure reducing device with respect to the operating time. It shows the relationship between the opening degree, the discharge pressure, and the feedwater 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 in the conventional example, as shown in FIG. When the feedwater temperature detecting means 8 as the detecting means 12 immediately before the completion of the boiling detects the detected temperature Th immediately before the completion of the boiling (which is lower than the boiling temperature T1), the control means 11 uses this detection signal to reduce the pressure. The valve opening of the device 3 is increased (opened).

At this time, the discharge pressure of the compressor decreases from P1 to P2. Thereafter, as the operation time elapses, the feedwater temperature further rises, and the discharge pressure rises accordingly. And
The water supply temperature at which the water supply temperature detection means 8 becomes the normal upper limit pressure P
When T3a is detected, the compressor is stopped and the heating operation ends. 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. The water temperature at the operating limit rises from T3 to T3a, which makes it clear that the operating range is large, and that an effective hot water layer is created, and the unusable hot water layer is less than the conventional example as shown in FIG. It becomes less and the hot water capacity of the hot water tank can be used effectively.

As described above, in the invention of this embodiment,
A refrigerant circulation circuit in which a compressor, a refrigerant-to-water heat exchanger, a pressure reducing device, and an evaporator are sequentially connected, a hot water tank, a circulation pump, and a hot-water supply circuit in which the refrigerant-water heat exchanger is sequentially connected, and the entire hot water tank boils up And a control means for controlling to open the valve opening of the pressure reducing device when a signal from the immediately before completion of the boiling becomes a predetermined signal. By this, when the boiling is approaching completion and the discharge pressure of the compressor rises, the discharge pressure is controlled to be low by controlling the opening of the pressure reducing device to open,
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 can be effectively used.

(Embodiment 2) FIG. 4 is a configuration diagram of a heat pump water heater in Embodiment 2 of the present invention, and FIG. 5 is an explanatory diagram showing discharge pressure with respect to valve opening of a pressure reducing device of the heat pump water heater. FIG. 6 is an explanatory diagram showing a change amount of a valve opening of the pressure reducing device with respect to an outside air temperature of the heat pump water heater and a detected temperature immediately before completion of boiling.

The present embodiment differs from the first embodiment shown in FIG. 1 in that the outside air temperature detecting means 13 provided near the evaporator 4 for detecting the outside air temperature, and the valve opening of the pressure reducing device 3 for the outside air temperature. The first storage means 14 for storing the degree of change of the temperature is provided, and the control means 11a controls the outside air temperature detection means 13
And the signal of the first storage means 14 is fetched to control the pressure reducing device 3.

The first storage means 14 sets the amount of change of the valve opening of the pressure reducing device 3 with respect to the stored outside air temperature based on the following relationship. That is, FIG. 5 shows the valve opening of the pressure reducing device 3 on the horizontal axis, the outside air temperature as a parameter (for example, 5 # C in winter, 18 # C in the middle period, 18 # C in summer, for example), and the vertical axis. Shows the relationship between the discharge pressure and the valve opening of the pressure reducing device 3 at a certain feedwater temperature. As shown in the figure,
As the valve opening of the pressure reducing device 3 increases, the discharge pressure decreases. Therefore, if the amount of change in the valve opening of the pressure reducing device 3 is determined in order to reduce the discharge pressure from P1 to P2, winter (for example, 5
#S) in the middle period (for example, 18 # C).
2. In summer (for example, 18 # C), it is $ S3.

FIG. 6 shows the outside air temperature on the horizontal axis and the amount of change in the valve opening of the pressure reducing device 3 on the vertical axis, and detects the amount of change in the valve opening of the pressure reducing device 3 with respect to the outside air temperature and immediately before the completion of boiling. It shows the relationship with temperature. The relationship between the outside air temperature and the amount of change of the valve opening in the pressure reducing device 3 is determined by the outside air temperature (5 # C in winter, 18 # C in the middle period, 18 # in summer) obtained in FIG.
C) ($ S1 in winter, $ S2 in the middle period, $ S3 in summer). The relationship between the outside air temperature and the detected temperature immediately before the completion of boiling is as follows: each outside air temperature (for example, 5 # C in winter, 18 # C in the middle period, 18% in summer, for example).
In C), it can be determined by obtaining the feed water temperature at which the discharge pressure becomes P1 (the detected temperature Th immediately before the completion of boiling).
FIG. 6 shows these relationships, and the relationships (tables) in FIG. 6 are stored in the first storage unit 14 in advance. In the drawing, the same reference numerals as those in FIG. 1 of the first embodiment denote the same components, and a detailed description thereof will be omitted.

Next, the operation and operation of the above embodiment will be described. The control means 11a periodically detects the supply water temperature from the supply water temperature detection means 8, which is the detection means 12 immediately before the completion of boiling, and further detects the outside air temperature from the outside air temperature detection means 13. Then, from the table stored in the first storage means 14, the change amount of the valve opening of the pressure reducing device 3 with respect to the outside air temperature and the detected temperature Th immediately before completion of boiling are obtained. And
If the feed water temperature obtained from the feed water temperature detecting means 8 is lower than the detection temperature Th immediately before the completion of boiling, the valve opening of the pressure reducing device 3 is not changed. Conversely, if the feed water temperature is higher than the detection temperature Th immediately before the completion of boiling, The valve opening of the pressure reducing device 3 is changed (opened) by the change amount of the valve opening of the pressure reducing device 3 obtained from the table of the first storage means 14. When the valve opening of the pressure reducing device 3 is changed, the discharge pressure decreases from P1 to P2. Thereafter, as described in the first embodiment, the feedwater temperature further increases with the elapse of the operation time, and the discharge pressure increases accordingly. Then, when the feedwater temperature detecting means 8 detects the feedwater temperature T3a at which the normal upper limit pressure P shown in FIG. 2 is reached, the compressor is stopped and the heating operation is ended.

As described above, in the present invention,
By providing a control means for determining the amount of change in the valve opening of the pressure reducing device in accordance with the outside air temperature obtained from the outside air temperature detecting means for detecting the outside air temperature, the optimum valve opening of the pressure reducing device in accordance with the outside air temperature is provided. Therefore, the hot water capacity of the hot water storage tank can be used effectively, and an efficient hot water supply heating operation can be performed.

(Embodiment 3) FIG. 7 is a block diagram of a heat pump water heater according to a third embodiment of the present invention. FIG. 8 is a diagram showing the water supply temperature, discharge pressure, valve opening degree of the pressure reducing device and the operation time of the heat pump water heater. It is explanatory drawing which shows the operation state of a compressor. This embodiment is different from the first embodiment shown in FIG. 1 in that the water supply temperature storage means 15 is provided and the control means 11b
Is that the pressure reducing device 3 is controlled by taking in the signal of the feedwater temperature storage means 15 in addition to the signal of the detection means 12 immediately before the completion of boiling.

The supply water temperature storage means 15 sets the stored supply water temperature based on the following relationship. That is, FIG. 8 shows the operation time on the horizontal axis, the feed water temperature, the discharge pressure, the valve opening of the pressure reducing device, and the operating state of the compressor on the vertical axis, and the feed water temperature, the discharge pressure, and the pressure reduction device with respect to the operation time. 4 shows the relationship between the valve opening and the operating state of the compressor. Th1, Th2 (Th1 <Th2) shown in FIG.
Is the detected temperature Th immediately before the completion of boiling, which is the first detected temperature immediately before the completion of boiling and the second detected temperature immediately before the completion of the boiling, respectively. Detected temperature Th immediately before completion of the first boiling
The first and second detected temperatures Th2 immediately before the completion of boiling are stored in the feedwater temperature storage means 15. In the figure, the same reference numerals as those in the first embodiment shown in FIG.
Detailed description is omitted.

Next, the operation and operation of the above embodiment will be described. As described above, 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. The control means 11b periodically detects the feed water temperature from the feed water temperature detecting means 8, which is the detecting means 12 immediately before the completion of the boiling, and further stores the first detected temperature Th1 immediately before the completion of the boiling stored in the feed water temperature storage means 15. Ask for. And
If the feed water temperature obtained from the feed water temperature detecting means 8 is lower than the first detected temperature Th1 immediately before the completion of the boiling, the valve opening of the pressure reducing device 3 is not changed. If it is higher than the detected temperature Th1, the valve opening of the pressure reducing device 3 is changed (opened). When the valve opening of the pressure reducing device 3 is changed in this manner, the discharge pressure decreases. After that, the control means 11
b, the feed water temperature is periodically detected from the feed water temperature detecting means 8 which is the detecting means 12 immediately before the completion of boiling, and the second detected temperature Th2 immediately before the completion of the boiling stored in the feed water temperature storage means 15 is obtained. . Then, the water supply temperature detecting means 8
Is the detected temperature T just before the completion of the second boiling.
If it is lower than h2, the valve opening of the pressure reducing device 3 is not changed, and conversely, the feedwater temperature is the detected temperature Th2 immediately before the completion of the second boiling.
If it is higher, the valve opening of the pressure reducing device 3 is changed (opened).
Further, when the valve opening of the pressure reducing device 3 is changed in this manner, the discharge pressure of the compressor is similarly reduced. Thereafter, as described in the first embodiment, the supply water temperature further increases with the elapse of the operation time, and the discharge pressure increases accordingly. Then, the feedwater temperature detecting means 8 detects the feedwater temperature T3 at which the service upper limit pressure P is reached.
When a is detected, the compressor is stopped and the heating operation is terminated.

As described above, in the invention of this embodiment,
By providing control means for changing the valve opening of the pressure reducing device for each of a plurality of predetermined water supply temperatures, the valve opening of the pressure reducing device is optimally changed according to the water supply temperature, so that it is effective. Since the useless area that cannot be used as hot water is reduced, the hot water capacity of the hot water storage tank can be effectively used, and an efficient hot water supply heating operation can be performed.

Further, in the present embodiment, two feed water temperatures are set as the detected temperature Th immediately before the completion of boiling, but even if three or more feed water temperatures are set, the same operation and effect as in the present embodiment can be obtained. .

(Embodiment 4) FIG. 9 is a block diagram of a heat pump water heater according to Embodiment 4 of the present invention, and FIG. 10 is an explanatory diagram showing discharge pressure and valve opening of a pressure reducing device with respect to water supply temperature of the heat pump water heater. FIG. 11 is an explanatory diagram showing the amount of change in the valve opening of the pressure reducing device with respect to the feed water temperature of the heat pump water heater.

The present embodiment is different from the third embodiment shown in FIG. 7 in that a second storage means 16 for storing the change amount of the valve opening of the pressure reducing device with respect to the feed water temperature is provided, and the control means 11c is provided with a boiler. Water supply temperature storage means 15 for storing the temperature immediately before the completion of the first boiling and the second detected temperature Th2 immediately before the completion of the first boiling.
In addition to the above signal, the signal of the second storage means 16 is fetched to control the pressure reducing device 3.

The second storage means 16 sets the amount of change of the valve opening of the pressure reducing device with respect to the stored feed water temperature based on the following relationship. That is, FIG. 10 shows the relationship between the discharge pressure and the valve opening of the pressure reducing device with respect to the water supply temperature, in which the horizontal axis shows the feed water temperature, the vertical axis shows the discharge pressure and the valve opening of the pressure reducing device. is there. In the figure, the dotted line indicates a case where the valve opening of the pressure reducing device 3 is constant. As can be seen from the figure, the discharge pressure sharply increases as the feedwater temperature increases. Th1 and Th shown in FIG.
2, Th3, Th4, Th5 (Th1 <Th2 <Th
3 <Th4 <Th5) is the detected temperature T immediately before the completion of boiling.
h is the feedwater temperature indicating the first, second, third, fourth, and fifth detected temperatures immediately before the completion of boiling, respectively. The first to fifth detected temperatures immediately before the completion of boiling are stored in the feedwater temperature storage means 15. Then, the feed water temperature detected by the feed water temperature detecting means 8 which is the detecting means 12 just before the completion of boiling is stored in the feed water temperature storing means 15 and the detected temperature immediately before the completion of the boiling Th (Th1, Th2, Th3, Th, Th)
4, Th5) or more, the valve opening of the pressure reducing device 3 is changed (△ S1, △ S2, △ S3, △ S4, △ S5, respectively).
Do (open). At this time, the change amount of the valve opening degree in the pressure reducing device 3 is made larger as the detected temperature immediately before the completion of the boiling is higher, as shown in FIG. That is, when the detected temperature immediately before the completion of boiling is Th1 <Th2 <Th3 <Th4 <Th5, the change amount of the valve opening of the pressure reducing device 3 is set to {S1 <{S2 <}.
It is assumed that S3 <△ S4 <△ S5. In this way, as shown by the solid line in FIG.

FIG. 11 shows the feed water temperature on the horizontal axis, the amount of change in the valve opening of the pressure reducing device 3 on the vertical axis, and the relationship between the amount of change in the valve opening of the pressure reducing device 3 and the water supply temperature. This relationship is stored in the second storage means 16. In the drawing, the same reference numerals as in the third embodiment denote the same components, and a detailed description thereof will be omitted.

Next, the operation and operation of the above embodiment will be described. The control means 11c periodically detects the feed water temperature detected by the feed water temperature detecting means 8, which is the detecting means 12 immediately before the completion of boiling. Then, the detected temperature Th (Th1, Th1) immediately before the completion of the boiling stored in the water supply temperature storage means 15 is stored.
2, Th3, Th4, Th5). If the feed water temperature obtained from the feed water temperature detecting means 8 is lower than the detection temperature Th immediately before the completion of boiling, the valve opening of the pressure reducing device 3 is not changed, and conversely, the feed water temperature is lower than the detection temperature Th immediately before the completion of boiling. If it is higher, the change amount of the valve opening degree of the pressure reducing device with respect to the feed water temperature stored in the second storage means 16 (△ S1,
The valve opening of the pressure reducing device 3 is changed (opened) by ΔS2, ΔS3, ΔS4, ΔS5).

As described above, in the invention of this embodiment,
By providing control means for increasing the amount of change in the valve opening of the pressure reducing device as the water supply temperature becomes higher, the discharge pressure is increased by increasing the amount of change in the valve opening of the pressure reducing device at a high water supply temperature where the discharge pressure rises greatly. Is greatly reduced, and the valve opening of the decompression device is optimally changed in accordance with the feed water temperature, so that the hot water capacity of the hot water storage tank can be effectively used, and an efficient hot water supply heating operation can be performed.

In the present embodiment, five feed water temperatures are set as the detected temperature Th immediately before the completion of the boiling.
Even if two or more supply water temperatures are set, the same operation and effect as in the present embodiment can be obtained.

(Embodiment 5) FIG. 12 is a block diagram of a heat pump water heater according to Embodiment 5 of the present invention, and FIG. 13 is a diagram showing the water supply temperature, the valve opening degree and discharge pressure of the pressure reducing device with respect to the operation time of the heat pump water heater. FIG. This embodiment is different from the first embodiment shown in FIG.
And the controller 11d controls the pressure reducing device 3 by taking in the signal of the timer 17 in addition to the signal of the detection unit 12 immediately before the completion of boiling. That is, when the supply water temperature reaches the detected temperature Th immediately before the completion of boiling, the control unit 11d performs control to increase the valve opening of the pressure reducing device 3 at a predetermined time interval ΔT preset by the timer 17. Things.

That is, in FIG. 13, the horizontal axis shows the degree of operation time, and the vertical axis shows the water supply temperature, the valve opening degree of the pressure reducing device, and the discharge pressure. It shows the relationship with the discharge pressure. As described above, the water supply temperature rises with the operation time in the hot water tank 5 at the hot water mixing layer. In the figure, the dotted line indicates the case where the valve opening of the pressure reducing device 3 is kept constant, and the discharge pressure increases rapidly as the operation time elapses and the feedwater temperature increases. Therefore, when the supply water temperature reaches the detection temperature Th immediately before the completion of boiling, the valve opening of the pressure reducing device 3 is increased at every predetermined time interval ΔT preset by the timer 17. By doing so, the discharge pressure (the portion indicated by the solid line) can be lower than in the case where the valve opening of the pressure reducing device 3 is constant as shown in FIG. In the figure, the same reference numerals as in the first embodiment shown in FIG. 1 denote the same components, and a detailed description thereof will be omitted.

Next, the operation and operation of the above embodiment will be described. That is, the control means 11d periodically detects the feed water temperature from the feed water temperature detecting means 8 which is the detecting means 12 just before the completion of boiling. Then, if the feed water temperature obtained from the feed water temperature detecting means 8 is higher than the detected temperature immediately before the completion of boiling, a predetermined time interval に よ っ て
The valve opening of the pressure reducing device 3 is opened step by step every T.

As described above, in the invention of this embodiment,
By providing the control means 11d for changing the valve opening of the pressure reducing device 3 at predetermined time intervals, the valve opening of the pressure reducing device is optimally changed immediately before the completion of boiling. The hot water supply can be used effectively, and an efficient hot water supply heating operation can be performed.

(Embodiment 6) FIG. 14 is a block diagram of a heat pump water heater according to Embodiment 6 of the present invention. FIG. 15 is a diagram showing water supply temperature, valve opening degree and discharge pressure of a pressure reducing device with respect to operation time of the heat pump water heater. FIG. The present embodiment is different from the fifth embodiment shown in FIG. 12 in that a time interval for changing the valve opening of the pressure reducing device 3 is set to be smaller as the boiling is completed, and the time interval storing means 18 is provided. The control means 11e includes a detection means 12 immediately before the completion of boiling.
In addition to the above signal, the signal of the timer 17 based on the signal of the time interval storage means 18 is fetched, and the time interval for changing the valve opening of the pressure reducing device 3 is controlled to be smaller as the boiling is completed. It is that you are.

That is, in FIG. 15, the horizontal axis shows the operation time, the vertical axis shows the water supply temperature, the valve opening of the pressure reducing device and the discharge pressure, and the water supply temperature and the valve opening of the pressure reducing device with respect to the operation time. It shows the relationship with the discharge pressure. As described above, the water supply temperature rises as the operation time elapses in the hot water tank 5 in the hot water / water mixture layer. In the figure, the dotted line indicates the case where the valve opening of the pressure reducing device 3 is kept constant, and the discharge pressure (the portion indicated by the dotted line) increases rapidly as the operation time elapses and the feedwater temperature increases. Therefore, when the supply water temperature becomes the detection temperature Th1 immediately before the completion of the first boiling, the valve opening of the pressure reducing device 3 is increased stepwise at every predetermined first time interval ΔT1. Then, the feedwater temperature further rises, and the feedwater temperature becomes equal to the detected temperature T just before the completion of the second boiling.
h2, the pressure reducing device 3 is provided at every predetermined second time interval ΔT2 (ΔT2 <ΔT1) smaller than the first time interval ΔT1.
Of the valve is gradually increased.

As described above, if the time interval for correcting the valve opening of the pressure reducing device 3 is shortened at the time of high supply water temperature at which the discharge pressure rises sharply, the valve opening of the pressure reducing device 3 is reduced as shown in FIG. As compared with a fixed case, the discharge pressure (solid line portion) can be reduced, and in particular, a sharp increase in the discharge pressure can be prevented, so that the range of the hot water supply heating operation can be expanded. Therefore, the above-described first time interval ΔT1 and second time interval ΔT2 are stored in the time interval storage means 18. In the figure, the parts denoted by the same reference numerals as those in the fifth embodiment shown in FIG. 12 have the same configuration, and the detailed description is omitted.

Next, the operation and operation of the above embodiment will be described. That is, the control means 11e periodically detects the feed water temperature from the feed water temperature detecting means 8 which is the detecting means 12 immediately before the completion of boiling. Then, the feed water temperature obtained from the feed water temperature detecting means 8 is equal to the detected temperature Th1 immediately before the completion of the first boiling.
If it is higher, the first time interval ΔT1 is detected by the signal from the time interval storage means 18. Then, according to a signal from the timer 17, the valve opening of the pressure reducing device 3 is opened stepwise at first time intervals ΔT1. Further, if the feedwater temperature rises and the feedwater temperature obtained from the feedwater temperature detecting means 8 is higher than the second detected temperature immediately before the completion of boiling Th2, the second time interval ΔT2
Is detected. Then, the valve opening of the pressure reducing device 3 is gradually opened at every second time interval ΔT2 by a signal from the timer 17.

As described above, in the present embodiment,
By providing a control means that makes the time interval for changing the valve opening of the pressure reducing device smaller as the boiling time approaches the completion,
When the discharge pressure rises more as the boiling is completed, the change in the valve opening of the pressure reducing device is increased and the discharge pressure is greatly reduced, and the optimal valve opening of the pressure reducing device is changed. The capacity can be used effectively, and an efficient hot water supply heating operation can be performed.

In this embodiment, two time intervals (ΔT1, ΔT1) are used as time intervals for changing the valve opening of the pressure reducing device.
2) is set, but even if three or more time intervals are set,
The same operation and effect as the embodiment can be obtained.

(Embodiment 7) FIG. 16 is a block diagram of a heat pump water heater according to Embodiment 7 of the present invention. FIG. 17 is a diagram showing water supply temperature, rotation speed, flow rate, and discharge pressure of a circulation pump with respect to the operation time of the heat pump water heater. It is explanatory drawing which shows the valve opening degree of a decompression device. This embodiment is different from the first embodiment shown in FIG. 1 in that a time measurement in which the flow rate of the circulation pump 6 reaches the maximum flow rate through the flow rate detection means 10 is performed as the detection means 12 immediately before the completion of boiling. Means 1
9 and the control means 11f is provided with the time measuring means 19
Is received, and the pressure reducing device 3 is controlled. In the drawing, the same reference numerals as in the first embodiment denote the same components, and a detailed description thereof will be omitted.

Next, the operation and operation of the above embodiment will be described. FIG. 17 shows the degree of operation time on the horizontal axis, the feedwater temperature, the rotation speed and flow rate of the circulation pump 6, the discharge pressure, and the valve opening degree of the pressure reducing device 3 on the vertical axis. 6 shows the relationship among the rotation speed and flow rate, the discharge pressure, and the valve opening of the pressure reducing device 3. As described above, the flow rate control means 10 controls the rotation speed of the circulation pump 6 based on the signal from the boiling temperature detection means 9 provided at the water-side outlet of the refrigerant-to-water heat exchanger 2, and The outlet water temperature (boiling temperature) of the exchanger 2 is raised so as to be substantially constant. Since the temperature of the water supply rises with the operation time in the hot and cold water mixing layer in the hot water storage tank 5, the circulation pump 6 increases the water flow rate of the refrigerant-to-water heat exchanger 2.
Increase the number of revolutions. However, even when the rotation speed of the circulation pump 6 reaches the maximum rotation speed, the water supply temperature may still rise. In this case, the boiling temperature, which is the outlet water temperature of the refrigerant-to-water heat exchanger 2, rises, and the discharge pressure also rises sharply. Therefore, if the rotation speed of the circulation pump 6 reaches the maximum rotation speed for a predetermined operation time and is controlled to open the valve opening of the pressure reducing device 3, the discharge pressure decreases as shown in FIG. It is possible to continue the heating operation.

That is, the control means 11f periodically detects the time during which the flow rate of the circulation pump 6 reaches the maximum flow rate from the time measurement means 19, which is the detection means 12 immediately before the completion of boiling. If the detected time is longer than a predetermined operation time set in the control means 11f in advance, the valve opening of the pressure reducing device 3 is opened by a signal from the time measuring means 19.

As described above, in the invention of this embodiment, the time measuring means for calculating the time during which the flow rate of the circulating pump reaches the maximum flow rate when the flow rate of the circulation pump has reached the maximum flow rate is used as the detection means immediately before the completion of boiling. With this arrangement, it is detected that the capacity of the circulating pump has reached a maximum for a predetermined time, the valve opening of the pressure reducing device is changed, the discharge pressure is kept low, and the heating operation is continued. The hot water supply heating operation can be performed up to the temperature, and the hot water capacity of the hot water storage tank can be used effectively.

(Eighth Embodiment) FIG. 18 is a block diagram of a heat pump water heater according to an eighth embodiment of the present invention, and FIG. 19 is a diagram showing the water supply temperature, discharge pressure, valve opening degree of the pressure reducing device and the operation time of the heat pump water heater. FIG. This embodiment is different from the first embodiment shown in FIG. 1 in that a discharge pressure detection unit 12 is connected to the discharge side of the compressor 1 in a refrigerant circulation circuit of a heat pump as a detection unit 12 immediately before completion of boiling to detect a discharge pressure. A means 20 is provided, and the control means 11g receives the output signal of the discharge pressure detecting means 20 and controls the pressure reducing device 3. In the drawing, the same reference numerals as in the first embodiment denote the same components, and a detailed description thereof will be omitted.

Next, the operation and operation of the above embodiment will be described. 19 shows the degree of operation time on the horizontal axis, the feed water temperature, discharge pressure, and the valve opening of the pressure reducing device on the vertical axis, and the relationship between the water supply temperature, discharge pressure, and the valve opening of the pressure reducing device with respect to the operation time. It is shown. As described above, when the temperature reaches the portion of the hot water tank in the hot water tank, the water supply temperature increases with the operation time, and the discharge pressure also increases accordingly. Therefore,
When the discharge pressure reaches the reference pressure P, the valve opening of the pressure reducing device 3 is increased. As a result, the discharge pressure can be reduced.

That is, the control means 11g periodically controls the discharge pressure detecting means 2 which is the detecting means 12 immediately before the completion of boiling.
From 0, the discharge pressure is detected. If the discharge pressure obtained from the discharge pressure detecting means 20 is higher than the reference pressure P preset in the control means 11g, the valve opening of the pressure reducing device 3 is opened by the signal from the discharge pressure detecting means 20. Such control is repeatedly performed by the control means 11g so that the discharge pressure does not exceed the reference pressure P.

As described above, in the invention of this embodiment,
Using the discharge pressure detection means as the detection means immediately before the completion of boiling, if the detected discharge pressure reaches the set reference pressure,
Equipped with control means for opening the valve opening of the decompression device, the hot water capacity of the hot water tank can be used effectively, and the discharge pressure is controlled directly, so the more reliable durability of the compressor is improved. It becomes something.

[0064]

As described above, according to the first to eighth aspects of the present invention, the valve opening degree of the pressure reducing device is increased when the completion of boiling is approached and the discharge pressure of the compressor increases. , The discharge pressure is kept low, and the hot water supply heating operation can be performed up to a high supply water temperature, so that there is less wasteful area that cannot be used as effective hot water, and the hot water capacity of the hot water storage tank can be used effectively. Therefore, in order to satisfy a larger hot water supply load with a hot water tank of the same size as the conventional one, and conversely, in order to satisfy a hot water supply load of the same size as the conventional one, the hot water tank can be made smaller than the conventional one. Flexibility and cost reduction. Further, 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 is an explanatory diagram showing an operating state of a compressor, a valve opening degree of a pressure reducing device, a discharge pressure, and a feed water temperature with respect to an operation time of the heat pump water heater.

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

FIG. 4 is a configuration diagram illustrating a heat pump water heater according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a discharge pressure with respect to a valve opening degree of a pressure reducing device of the heat pump water heater.

FIG. 6 is an explanatory diagram showing a change amount of a valve opening of a pressure reducing device with respect to an outside air temperature of the heat pump water heater and a detected temperature immediately before completion of boiling.

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

FIG. 8 is an explanatory diagram showing a feed water temperature, a discharge pressure, a valve opening degree of a pressure reducing device, and an operation state of a compressor 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 an explanatory diagram showing a discharge pressure and a valve opening degree of a pressure reducing device with respect to a water supply temperature of the heat pump water heater.

FIG. 11 is an explanatory diagram showing a change amount of a valve opening degree of a pressure reducing device with respect to a feed water temperature of the heat pump water heater.

FIG. 12 is a configuration diagram illustrating a heat pump water heater according to a fifth embodiment of the present invention.

FIG. 13 is an explanatory diagram showing a feed water temperature, 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. 14 is a configuration diagram showing a heat pump water heater according to Embodiment 6 of the present invention.

FIG. 15 is an explanatory diagram showing a feed water temperature, 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. 16 is a configuration diagram showing a heat pump water heater according to a seventh embodiment of the present invention.

FIG. 17 is an explanatory diagram showing the feed water temperature, the rotation speed and flow rate of the circulation pump, the discharge pressure, and the valve opening of the pressure reducing device with respect to the operation time of the heat pump water heater.

FIG. 18 is a configuration diagram illustrating a heat pump water heater according to an eighth embodiment of the present invention.

FIG. 19 is an explanatory diagram showing a water supply temperature, a discharge pressure, and a valve opening degree of a pressure reducing device with respect to an operation time of the heat pump water heater.

FIG. 20 is a configuration diagram showing a heat pump water heater in a conventional example.

FIG. 21 is an explanatory view showing a temperature distribution of a hot water storage tank of the heat pump water heater.

FIG. 22 is an explanatory diagram showing a discharge pressure with respect to a water supply 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 8 Supply water temperature detection means 10 Flow rate control means 11, 11a, 11b, 11c Control means 11d, 11e, 11f, 11g Control means 12 Detecting means immediately before completion of boiling 13 External temperature detecting means 14 First storing means 15 Water supply temperature storing means 16 Second storing means 17 Timer 18 Time interval storing means 19 Time measuring means 20 Discharge pressure detecting means

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

Claims (8)

[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. The connected hot water supply circuit, flow control means for controlling the flow rate of the circulation pump in order to keep the boiling temperature, which is the water-side outlet water temperature of the refrigerant-to-water heat exchanger, constant, and immediately before the entire hot water storage tank is heated A heat pump water heater comprising: means for detecting immediately before the completion of boiling and a control means for controlling a valve opening of the pressure reducing device to be opened when a signal from the means for immediately before the completion of boiling becomes a predetermined signal. . 2. The heat pump water heater according to claim 1, wherein the control means controls a change amount of a valve opening of the pressure reducing device according to the outside air temperature detected by the outside air temperature detection means. 3. As a means for detecting immediately before the completion of boiling,
A feedwater temperature detecting means for detecting a feedwater temperature that is a water-side inlet water temperature of the refrigerant / water heat exchanger; and each time the feedwater temperature detecting means detects a plurality of predetermined feedwater temperatures, the valve opening of the pressure reducing device is increased. The heat pump water heater according to claim 1, further comprising control means for controlling to open the heat pump. 4. The heat pump water heater according to claim 3, wherein the control means controls the amount of change of the valve opening of the pressure reducing device to be larger as the temperature of the water supply becomes higher. 5. The heat pump water heater according to claim 1, wherein the control means changes the valve opening of the pressure reducing device at predetermined time intervals. 6. The heat pump water heater according to claim 5, wherein the control means makes the time interval of the change of the valve opening in the pressure reducing device smaller as the boiling is completed. 7. The apparatus according to claim 1, further comprising a time measuring means for calculating a time when the circulation pump reaches the maximum flow rate when the flow rate of the circulation pump reaches the maximum flow rate as the detection means immediately before the completion of boiling. The heat pump water heater described. 8. The heat pump water heater according to claim 1, further comprising a discharge pressure detecting means as a detecting means immediately before the completion of boiling.