JP2002340402A - 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 flow rate control means 10 for controlling the opening of a flow rate regulating valve 11 so that a boiling-up outlet water temperature at the water side of a refrigerant to water heat exchanger 2 is kept at a constant value; a means 13 for detecting the condition immediately before completion of boiling-up to detect right before boiling-up of the whole of the hot water storage tank 5; and a control means 12 to effect control such that the number of revolutions of a compressor is decreased when a signal from the means 13 is changed into a given signal. Since, in the case of boiling-up completion approaching and the discharge pressure of the compressor 1 being increased, control is effected such that the number of revolutions of the compressor is decreased, hot water supplying/heating operation is practicable to a high water supply temperature, hot water capacity of the hot water storage tank 5 can be effectively utilized, and further 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. 22 is a configuration diagram of a conventional heat pump water heater. In FIG. 22, a compressor 1, a refrigerant-to-water heat exchanger 2,
Refrigerant circulation circuit including decompression device 3, evaporator 4, hot water storage tank 5, circulation pump 6, refrigerant-to-water heat exchanger 2, auxiliary heater 7
, And the high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 1 flows into the refrigerant-to-water heat exchanger 2, where it heats the water sent from the circulation pump 6. 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. .

[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. 23 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, 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. 24 shows the relationship between the feed pressure of the compressor 1 and the feed water temperature, with the horizontal axis representing the temperature of the feed water 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 the above-mentioned T3 and T3
u 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 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 compressor so as to reduce the rotation speed of the variable capacity compressor when detecting the fact. Therefore, when the discharge pressure of the compressor nears the completion of boiling and the discharge pressure of the compressor rises, the heating capacity is controlled so as to decrease and the discharge pressure is kept low.
The hot water supply heating operation can be performed up to a high supply water temperature.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The invention according to a first aspect of the present invention is directed to a refrigerant circulation circuit in which a compressor, a refrigerant-to-water heat exchanger, a pressure reducing device, and an evaporator, which are sequentially connected, a hot water tank, a circulation pump, A hot water supply circuit in which refrigerant-to-water heat exchangers are sequentially connected, and a heating completion detecting means for detecting immediately before the entire hot water tank is boiling, and when a signal from the heating completion detecting means becomes a predetermined signal, By providing control means for controlling the rotation speed of the compressor to be small, when the boiling is completed and the discharge pressure of the compressor increases,
The heating capacity is controlled so as to be reduced, 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 can be used effectively.

According to a second aspect of the present invention, there is provided a control means for determining a change range of the number of revolutions of the compressor in accordance with an outside air temperature obtained from an outside air temperature detecting means for detecting an outside air temperature. Since the optimum heating capacity is changed according to the temperature, 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 third aspect of the present invention, a control means for changing the number of revolutions of the compressor for each of a plurality of predetermined feedwater temperatures is provided, so that an optimum heating capacity according to the feedwater temperature can be obtained. Since the change is made, 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 control means for increasing the change width of the number of revolutions of the compressor as the temperature of the water supply increases, so that the rotation of the compressor at the time of the high temperature of the water supply where the rise in discharge pressure is large. The amount of change in the number is increased and the discharge pressure is greatly reduced to change the optimal heating capacity according to the feedwater temperature, 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. You can do it.

According to a fifth aspect of the present invention, an optimal heating capacity is changed immediately before the completion of boiling, by providing a control means for changing the number of revolutions of the compressor at predetermined time intervals. Therefore, 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, there is provided a control means for shortening the time interval for changing the rotation speed of the compressor as the boiling is completed, so that the discharge pressure is increased as the boiling is completed. When the pressure is large, the number of revolutions of the compressor is increased and the discharge pressure is greatly reduced, and the optimal heating capacity is changed, so that the hot water capacity of the hot water tank can be used effectively and efficient hot water supply heating operation Can be done.

According to a seventh aspect of the present invention, there is provided a time measuring means for measuring the time when the flow passing through the flow control valve reaches the maximum flow rate when the flow rate reaches the maximum flow rate as the detection means immediately before the completion of boiling. As a result, it detects that the boiling flow rate has reached the maximum for a predetermined time, changes the rotation speed of the compressor, 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 the present invention, the discharge pressure detecting means is used as the detecting means immediately before the completion of the boiling, and the control means is provided for controlling the rotational speed of the compressor to be reduced when the set reference pressure is reached. As a result, the hot water capacity of the hot water storage tank can be effectively used and the pressure is directly controlled, so that the durability of the compressor is more reliably improved.

According to a ninth aspect of the present invention, a hot water tank temperature detecting means for detecting a lower temperature of the hot water tank is used as a means for detecting immediately before completion of boiling, and when a predetermined hot water tank temperature is reached, the rotational speed of the compressor is reduced. The control means for controlling the temperature of the hot water storage tank can be effectively used, and the temperature is directly controlled by the temperature of the hot water storage tank. is there.

[0017]

(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 state of a hot water supply operation with respect to an operation time of the heat pump water heater, a rotation speed of a compressor and a discharge pressure. FIG. 3 is a graph showing the temperature distribution of the hot water tank of the heat pump water heater. Note that the same reference numerals are used for the same components as those in FIG.

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 / water heat exchanger 2,
The outlet water temperature (boiling temperature) of the refrigerant / water heat exchanger 2 is boiled almost constantly. Further, the control means 12 is a compressor driving means 14 for controlling the driving of the compressor 1 by a signal from the immediately before boiling completion detecting means 13 for detecting immediately before the completion of boiling.
The compressor drive means 14 has an inverter and varies the capacity of the compressor 1.
The flow regulating valve 11 includes an electric valve driven by a stepping motor. Here, as the detecting means 13 immediately before the completion of the boiling, the feed water temperature detecting means 8 for detecting the feed water temperature which is the water temperature at the water side inlet of the refrigerant / water heat exchanger 2 is used.

Next, the operation and operation will be described. In FIG. 2, the horizontal axis represents the operation time, and the vertical axis represents the state of the hot water supply operation, the number of revolutions of the compressor 1, the discharge pressure, and the temperature of the water supply. And the relationship between discharge pressure and feed 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, as shown in FIG. 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 (which is lower than the boiling temperature T1), the control means 12 starts the compressor driving means 1.
By sending a signal corresponding to a predetermined number of revolutions to 4,
The number of revolutions of the compressor 1 is reduced to lower the heating capacity. 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 detecting the feed water temperature T3a at which the service upper limit pressure P is reached, the compressor 1 is stopped, and the heating operation is terminated. It should be noted that the thick dotted line in the figure is the case of the conventional example in which the control of the rotation speed of the compressor 1 is not performed. Operation limit feedwater temperature from T3 to T
3a, which indicates that the operating range is increased.

FIG. 3 shows the temperature distribution of the hot water in the hot water storage tank 5.
In the sectional view of the hot water storage tank 5 shown on the left side of FIG.
The region below a is a region that can be boiled, and the region above Tu is a region that can be used as effective hot water. The area that cannot be used as effective hot water is the area between the hot water temperatures T3 and Tu in the case of the conventional example shown in FIG. 23, but the area between the hot water temperatures T3a and Tu (the hatched area) in the present embodiment. 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.

As described above, in this embodiment, the refrigerant circulating circuit in which the variable capacity compressor, the refrigerant / water heat exchanger, the pressure reducing device, and the evaporator are sequentially connected, the hot water tank, the circulation pump, the refrigerant A hot water supply circuit to which a water heat exchanger is sequentially connected; a heating completion detecting means for detecting immediately before the entire hot water tank is heated; and Control means for reducing the number of revolutions of the compressor, so that when the boiling is nearly completed and the discharge pressure of the compressor rises, the heating capacity is controlled to decrease, the discharge pressure is kept low, The hot water supply heating operation can be performed up to the supply water temperature, and the hot water capacity of the hot water storage tank can be effectively used.

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 regulating 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.

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 the critical point, as described in the conventional example of FIG. 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. 4 is a block diagram of a heat pump water heater according to Embodiment 2 of the present invention, FIG. 5 is a graph showing discharge pressure with respect to the number of revolutions of a compressor of the heat pump water heater, and FIG. It is a graph which shows the detection temperature just before completion of boiling with respect to the outside air temperature of a water heater, and the amount of change of the rotation speed of a compressor.

The present embodiment is different from the first embodiment in that an outside air temperature detecting means 15 for detecting the outside air temperature and a first storage means for storing a change amount of the rotation speed of the compressor 1 with respect to the outside air temperature. 16 is provided. The same reference numerals as in the first embodiment have the same configuration,
Description is omitted.

Next, the operation and operation will be described. In FIG. 5, the horizontal axis represents the rotation speed of the compressor 1, the outside air temperature is set as a parameter (for example, 5 ° C. in winter, 18 ° C. in the middle period, 29 ° C. in summer, for example), and the discharge pressure is plotted on the vertical axis. 4 shows the relationship between the rotation speed of the compressor 1 and the discharge pressure at a certain feedwater temperature. As shown in the figure, as the rotational speed of the compressor 1 decreases, the discharge pressure decreases. Therefore, if the amount of change in the rotation speed of the compressor 1 for reducing the discharge pressure from P1 to P2 is obtained, in winter (for example, 5 ° C.), ΔS1,
In the middle period (for example, 18 ° C.), ΔS2 and in the summer (for example, 29
° C), it becomes ΔS3.

FIG. 6 shows the outside air temperature on the horizontal axis, the detected temperature immediately before the completion of boiling and the change amount of the rotation speed of the compressor 1 on the vertical axis, and the detected temperature immediately before the completion of the boiling with respect to the outside air temperature and the compressor 1. 4 is a graph showing a relationship between the rotation speed and the amount of change. The relationship between the outside air temperature and the amount of change in the number of revolutions of the compressor 1 is determined by the outside air temperature (5 ° C. in winter, 18
° C, 29 ° C in the summer), and the amount of change (１S1 in the winter, △ S2 in the intermediate period, and △ S3 in the summer). The relationship between the outside air temperature and the detected temperature immediately before the completion of boiling is as follows: at each outside air temperature (for example, 5 ° C. in winter, 18 ° C. in the intermediate period, and 29 ° C. in summer, for example), the feedwater temperature (boiling up) at which the discharge pressure is P1 It can be determined by obtaining the detected temperature immediately before completion Th). FIG. 6 shows these relationships, and the relationships in FIG. 6 are stored in the first storage unit 16.

The control means 12 periodically detects the supply water temperature from the supply water temperature detection means 8 which is the detection means 13 immediately before the completion of boiling, and further detects the outside air temperature from the outside air temperature detection means 15. Then, the amount of change in the rotation speed of the compressor 1 with respect to the outside air temperature and the detected temperature Th immediately before the completion of boiling, which are stored in the first storage means 16, are obtained. If the feed water temperature determined by the feed water temperature detecting means 8 is lower than the detected temperature Th immediately before the completion of the boiling, the rotation speed of the compressor 1 is not changed.
If it is higher, the number of rotations of the compressor 1 is changed by sending a signal to the compressor driving means 14 by the change amount of the number of rotations of the compressor 1 obtained from the first storage means 16. Compressor 1
When the number of rotations 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. When the feedwater temperature detecting means 8 detects the feedwater temperature T3a at which the service upper limit pressure P is reached, the compressor 1
Is stopped and the heating operation is terminated.

As described above, in this embodiment, the control means for determining the amount of change in the rotational speed of the compressor in accordance with the outside air temperature obtained from the outside air temperature detecting means for detecting the outside air temperature is provided. Since the optimal heating capacity is changed according to the outside air 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.

(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 supply water temperature. The difference between the present embodiment and the first embodiment is that
7 is provided. Example 1
The portions denoted by the same reference numerals have the same configuration, and description thereof will be omitted.

Next, the operation and operation will be described. In FIG. 8, the horizontal axis represents the operation time, and the vertical axis represents the state of the hot water supply operation, the rotation speed of the compressor 1, the discharge pressure, and the temperature of the water supply. 4 is a graph showing the relationship between pressure, discharge pressure, and feedwater temperature. Th1 and Th2 (Th1 <Th2) shown in the figure are detected temperatures immediately before the completion of boiling, and are a detected temperature immediately before the completion of the first boiling and a second detected temperature immediately before the completion of the boiling, respectively. The detected temperature Th1 immediately before the completion of the first boiling and the detected temperature Th2 immediately before the completion of the second boiling are stored in the water supply temperature storage means 17.

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 12 periodically detects the feed water temperature from the feed water temperature detecting means 8 which is the detecting means 13 immediately before the completion of the boiling, and further detects the temperature immediately before the completion of the first boiling stored in the feed water temperature storage means 17. The temperature Th1 is obtained. And if the feed water temperature obtained from the feed water temperature detecting means 8 is lower than the detected temperature Th1 immediately before the completion of the first boiling,
The rotation speed of the compressor 1 is not changed. Conversely, if the feedwater temperature is higher than the detected temperature Th1 immediately before the completion of the first boiling, the compressor 1
Reduce the number of rotations. When the number of revolutions of the compressor 1 is changed, the discharge pressure decreases. After that, the control means 12 periodically detects the feed water temperature from the feed water temperature detecting means 8 which is the detecting means 13 immediately before the completion of the boiling, and further stores the second boiling stored in the feed water temperature storing means 17. The detected temperature Th2 immediately before completion is obtained. Then, the feed water temperature obtained from the feed water temperature detecting means 8 is equal to the detected temperature Th immediately before the completion of the second boiling.
If it is lower than 2, the rotation speed of the compressor 1 is not changed, and conversely,
If the feedwater temperature is higher than the second detected temperature Th2 immediately before the completion of boiling, a signal is sent to the compressor drive means 14 to reduce the rotation speed of the compressor 1. Similarly, when the rotation speed of the compressor 1 is changed, the discharge pressure decreases. afterwards,
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. When the feedwater temperature detecting means 8 detects the feedwater temperature T3a at which the normal upper limit pressure P is reached, the compressor 1 is stopped,
The heating operation ends.

As described above, in the present embodiment, by providing the control means for changing the rotation speed of the compressor 1 for each of a plurality of predetermined feedwater temperatures, the optimum heating in accordance with the feedwater temperature is provided. Since the capacity 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.

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

(Embodiment 4) FIG. 9 is a configuration diagram of a heat pump water heater according to Embodiment 4 of the present invention. FIG. 10 is an explanatory diagram showing the number of revolutions of the compressor and the discharge pressure with respect to the water supply temperature of the heat pump water heater. FIG. 11 is a graph showing the amount of change in the number of revolutions of the compressor with respect to the water supply temperature of the heat pump water heater.

The present embodiment is different from the third embodiment in that a second storage means 18 is provided for storing the amount of change in the number of revolutions of the compressor with respect to the feed water temperature. Note that the portions denoted by the same reference numerals as in the third embodiment have the same configuration,
Description is omitted.

Next, the operation and operation will be described. FIG.
Shows the relationship between the rotation speed of the compressor 1 and the discharge pressure with respect to the water supply temperature, with the horizontal axis representing the feedwater temperature and the vertical axis representing the rotation speed and the discharge pressure of the compressor 1. In the figure, the dotted line indicates the case where the rotation speed of the compressor 1 is constant.
As can be seen from the figure, the higher the feedwater temperature, the more rapidly the discharge pressure increases. Also, Th shown in FIG.
1, Th2, Th3, Th4, Th5 (Th1 <Th2
<Th3 <Th4 <Th5) is the feedwater temperature indicating the detected temperature Th immediately before the completion of the boiling, and is the first, second, third, fourth, and fifth detected temperatures immediately before the completion of the boiling, respectively. The first to fifth detected temperatures immediately before the completion of boiling are stored in the feedwater temperature storage means 17. Then, the feed water temperature detected by the feed water temperature detecting means 8 which is the detecting means 13 just before the completion of the boiling is stored in the feed water temperature storage means 17 and the detected temperature Th immediately before the completion of the boiling (Th1, Th2, Th3,
(Th4, Th5) or more, the rotation speed of the compressor 1 is reduced (△ S1, △ S2, △ S3, △ S4, respectively).
ΔS5). As shown in the figure, the change amount of the rotation speed of the compressor 1 at this time is larger when the detected temperature immediately before the completion of the boiling is higher. That is, the detected temperature Th immediately before the completion of boiling is Th
When 1 <Th2 <Th3 <Th4 <Th5, the change amount of the rotation speed of the compressor 1 is set to {S1 <△ S2 <△ S3 <△ S4 <△.
S5. In this way, as shown by the solid line in FIG. FIG. 11 shows the relationship between the feedwater temperature and the amount of change in the number of revolutions of the compressor 1, with the horizontal axis representing the feedwater temperature and the vertical axis representing the change in the number of revolutions of the compressor 1. This relationship is stored in the second storage means 18.

The control means 12 periodically detects the feed water temperature from the feed water temperature detecting means 8, which is the detecting means 13 immediately before the completion of boiling. Then, the detected temperature Th (Th1, Th1) immediately before the completion of the boiling stored in the feedwater temperature storage means 17 is stored.
2, Th3, Th4, Th5). If the feed water temperature determined by the feed water temperature detecting means 8 is lower than the detected temperature Th immediately before the completion of boiling, the rotation speed of the compressor 1 is not changed, and conversely, the feed water temperature is higher than the detected temperature Th immediately before the completion of boiling. For example, by sending a signal to the compressor driving means 14, the amount of change in the number of revolutions of the compressor 1 with respect to the feed water temperature stored in the second storage means 18 (１８S1, １S, respectively)
(2, ΔS3, ΔS4, ΔS5) The rotational speed of the compressor 1 is reduced.

As described above, in the present embodiment, the control means for increasing the change in the number of revolutions of the compressor as the feed water temperature becomes higher is provided. Since the discharge pressure is greatly reduced by increasing the amount of change in the number of rotations, and the optimal heating capacity is changed in accordance with the feed water temperature, the hot water capacity of the hot water tank can be used effectively, and the hot water heating can be performed efficiently You can drive.

In the present embodiment, five feed water temperatures are set as the detected temperature Th immediately before the completion of boiling. However, even if six or more feed water temperatures are set, the same operation and effect as those of the present embodiment can be obtained. Can be

(Embodiment 5) FIG. 12 is a diagram showing the configuration of a heat pump water heater according to Embodiment 5 of the present invention, and FIG. 13 shows the discharge pressure, the number of rotations of the compressor, and the water supply temperature with respect to the operation time of the heat pump water heater. FIG. This embodiment is different from the first embodiment in that a timer 19 is provided. 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.
Is a graph showing the relationship between the discharge pressure, the number of rotations of the compressor, and the temperature of the water supply with respect to the operation time, taking the operation time degree on the horizontal axis and the discharge pressure, the number of rotations of the compressor, and the water supply temperature on the vertical axis. It is. As described above, the feedwater temperature rises with the operation time in the hot water / water mixture layer. In the figure, the dotted line indicates the case where the rotation speed of the compressor 1 is 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 rotation speed of the compressor 1 is reduced at every predetermined time interval ΔT set in advance. By doing so, the discharge pressure can be reduced as compared with the case where the rotation speed of the compressor 1 is constant as shown in FIG.

That is, the control means 12 periodically supplies the feedwater temperature detecting means 8 which is the detecting means 13 immediately before the completion of boiling.
From the water supply temperature. Then, the water supply temperature detecting means 8
If the feedwater temperature obtained from the above is higher than the detected temperature Th immediately before the completion of boiling, a signal from the timer 19 sends a signal to the compressor driving means 14 at a predetermined time interval ΔT, so that the rotation speed of the compressor 1 is increased. Smaller.

As described above, in the present embodiment, the control means 12 for changing the number of revolutions of the compressor 1 at predetermined time intervals is provided, so that the optimum heating capacity is obtained immediately before the completion of boiling. 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 6) FIG. 14 is a block diagram of a heat pump water heater according to Embodiment 6 of the present invention, and FIG. 15 shows discharge pressure, compressor rotation speed and water supply temperature with respect to the operation time of the heat pump water heater. It is a graph.

The present embodiment is different from the fifth embodiment in that a time interval storage means 20 is provided. Note that the portions denoted by the same reference numerals as those of the fifth embodiment have the same configuration,
Description is omitted.

Next, the operation and operation will be described. FIG.
Shows the relationship between discharge pressure, compressor rotation speed, and feedwater temperature with respect to operation time, with the horizontal axis representing the degree of operation time and the vertical axis representing discharge pressure, compressor rotation speed, and feedwater temperature. It is. As described above, the feedwater temperature rises with the operation time in the hot water / water mixture layer. In the figure, the dotted line indicates the case where the rotation speed of the compressor 1 is constant, and the discharge pressure increases rapidly as the operation time elapses and the feedwater temperature increases. Therefore, when the supply water temperature becomes the detected temperature Th1 immediately before the completion of the first boiling, the rotation speed of the compressor 1 is reduced at every predetermined first time interval ΔT1. Then, when the feedwater temperature rises and the feedwater temperature becomes the detected temperature Th2 immediately before the completion of the second boiling, a predetermined second time interval ΔT2 smaller than the first time interval ΔT1.
Each time (△ T2 <△ T1), the rotation speed of the compressor 1 is reduced. As described above, when the time interval for correcting the rotation speed of the compressor 1 is shortened at a high supply water temperature at which the discharge pressure sharply increases, as shown in the figure, compared with the case where the rotation speed of the compressor 1 is constant, As a result, the discharge pressure can be reduced, and in particular, a sharp rise in the discharge pressure can be eliminated, so that the range of the hot water supply heating operation can be expanded. By the way, the first time interval ΔT1 and the second time interval ΔT2 are stored in the time interval storage means 20.

That is, the control means 12 periodically supplies the feedwater temperature detecting means 8 which is the detecting means 13 immediately before the completion of boiling.
From the water supply temperature. Then, the water supply temperature detecting means 8
If the supply water temperature obtained from the above is higher than the first detected temperature Th1 immediately before the completion of boiling, the first time interval ΔT1 is detected by the signal from the time interval storage means 20. And
With the signal from the timer 19, at every first time interval ΔT1,
By sending a signal to the compressor driving means 14, the rotation speed of the compressor 1 is reduced. In addition, the feedwater temperature rises,
If the feed water temperature obtained from the feed water temperature detecting means 8 is higher than the second detected temperature immediately before the completion of boiling, the second time interval ΔT 2 is detected by the signal from the time interval storing means 20. Then, by transmitting a signal from the timer 19 to the compressor driving means 14 at every second time interval ΔT2, the rotation speed of the compressor 1 is reduced.

As described above, in this embodiment, the control means for shortening the time interval for changing the rotational speed of the compressor as the boiling is completed is provided, so that the discharge pressure becomes smaller as the boiling is completed. When the rise in pressure is large, the change in the number of revolutions of the compressor is increased to greatly reduce the discharge pressure,
Since the optimum heating capacity is changed, the hot water capacity of the hot water storage tank can be used effectively, and the hot water supply heating operation can be performed efficiently.

In this embodiment, two time intervals (ΔT1, ΔT1) are used as time intervals for changing the number of revolutions of the compressor.
2) was set, but even if three or more time intervals were set,
The same operation and effect as in the present 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, and FIG. 17 is a diagram showing a rotational speed of a compressor, a discharge pressure, a flow rate, and a flow control valve with respect to an operation time of the heat pump water heater. 4 is a graph showing the opening degree and the supply water temperature of the circulating water.

This embodiment is different from the first embodiment in that the flow control valve 1 is used as the detection means 13 immediately before the completion of boiling.
1 is provided with a time measuring means 21 for measuring the time during which the flow rate passing through 1 is the maximum flow rate. 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 operation time degree on the horizontal axis, the rotation speed of the compressor 1, the discharge pressure, the flow rate, the opening degree of the flow control valve 11 and the feed water temperature on the vertical axis, and the rotation speed of the compressor 1 with respect to the operation time. 3 shows a relationship among a discharge pressure, a flow rate, an opening degree of the flow control valve 11, and a supply water temperature. As described above, the refrigerant-to-water heat exchanger 2
The flow control means 10 controls the opening degree of the flow control valve 11 by a signal from the boiling temperature detecting means 9 provided at the water side outlet of the refrigerant, and the outlet water temperature of the refrigerant-to-water heat exchanger 2 (boiling temperature).
Boil so that it is almost constant. Now, in the part of the hot and cold water mixing layer, the feed water temperature rises with the operation time, so the opening degree of the flow control valve 11 is increased so that the water flow rate of the refrigerant to the water heat exchanger 2 increases. However,
The opening of the flow control valve 11 is the maximum opening (that is, the maximum flow rate)
The water supply temperature may still rise even when the temperature reaches 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 opening of the flow control valve reaches the maximum opening continuously for a predetermined operation time, if the rotation speed of the compressor 1 is controlled to decrease, the discharge pressure decreases as shown in FIG. It becomes possible to continue the hot water supply heating operation.

That is, the control means 12 periodically detects the time during which the opening of the flow regulating valve 11 is at the maximum from the time measuring means 21 which is the detecting means 13 immediately before completion of boiling. If the detected time is longer than a predetermined operation time set in advance, a signal corresponding to a predetermined number of revolutions is transmitted to the compressor drive means 14 by a signal from the time measurement means 21 so that the compressor 1 Reduce the number of rotations.

As described above, in this embodiment, as the detection means immediately before the completion of boiling, when the opening of the flow control valve 11 reaches the maximum opening (that is, the maximum flow), the time during which the maximum flow is reached is obtained. , The opening degree of the flow regulating valve 11 is detected to be the maximum opening degree for a predetermined time, and the rotation speed of the compressor is changed. And keep the heating operation 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 can be effectively used.

(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 shows the number of rotations of the compressor, the discharge pressure, and the water supply temperature with respect to the operation time of the heat pump water heater. It is a graph.

The present embodiment is different from the first embodiment in that a discharge pressure detecting means 22 for detecting a discharge pressure is provided as the detecting means 13 immediately before the completion of boiling. 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.
The horizontal axis indicates the operating time, and the vertical axis indicates the rotational speed of the compressor, the discharge pressure, and the feedwater temperature, and indicates the relationship between the rotational speed of the compressor, the discharge pressure, and the feedwater temperature with respect to the operating time. is there. As described above, in the hot and cold water mixing layer, the feed water temperature increases with the operation time, and the discharge pressure also increases accordingly. Therefore, when the discharge pressure reaches the reference pressure P, the rotation speed of the compressor 1 is reduced. As a result, the discharge pressure can be reduced.

That is, the control means 12 periodically controls the discharge pressure detecting means 2 as the detecting means 13 immediately before the completion of boiling.
2, the discharge pressure is detected. If the discharge pressure obtained from the discharge pressure detecting means 22 is higher than the preset reference pressure P, a signal corresponding to a predetermined rotation speed is sent to the compressor driving means 14 by a signal from the discharge pressure detecting means 22. Thereby, the rotation speed of the compressor 1 is reduced. And
This is repeated.

As described above, in this embodiment, the discharge pressure detecting means is used as the detecting means immediately before the completion of boiling,
When the set reference pressure is reached, the control means for controlling the rotation speed of the compressor to be low is provided, so that the capacity of the hot water in the hot water tank can be used effectively and the pressure is directly controlled by the pressure. This will surely improve the durability of the machine.

(Embodiment 9) FIG. 20 is a block diagram of a heat pump water heater according to a ninth embodiment of the present invention, and FIG. 21 is a diagram showing a state of a hot water supply operation with respect to an operation time of the heat pump water heater, a rotation speed of the compressor, a discharge pressure, and the like. It is a graph which shows the lower part temperature of a hot water storage tank.

This embodiment is different from the first embodiment in that a hot water tank temperature detecting means 23 for detecting the lower temperature of the hot water tank 5 is provided as the means 13 for detecting immediately before the completion of boiling. 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 hot water supply operation state, the rotation speed of the compressor 1, the discharge pressure, and the lower temperature of the hot water storage tank 5 on the vertical axis. It shows the relationship between the rotation speed, the discharge pressure, and the lower temperature of the hot water storage tank 5. When the water flowing into the refrigerant-to-water heat exchanger 2 becomes the portion of the hot and cold water mixing layer, as shown in the figure, the lower temperature of the hot water storage tank 5 increases with the operation time. When the hot water tank temperature detecting means 23, 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 (which is lower than the boiling temperature T1), the control means 12 controls the compressor driving means. By sending a signal corresponding to a predetermined number of revolutions to 14, the number of revolutions of the compressor 1 is reduced and the heating capacity is reduced. At this time, the discharge pressure decreases from P1 to P2. Thereafter, as the operation time elapses, the lower temperature of the hot water tank 5 further rises, and the discharge pressure rises accordingly. Then, when the hot water tank temperature detecting means 23 detects the lower temperature T3a of the hot water tank 5 at which the normal upper limit pressure P is reached, the compressor 1 is stopped, and the heating operation ends. It should be noted that the thick dotted line in the figure is the case of the conventional example in which the control of the rotation speed of the compressor 1 is not performed. The lower temperature of the hot water storage tank 5 at the operation limit is from T3 to T3a.
To a high, it can be seen that the operating range is large.

As described above, in this embodiment, the hot water tank temperature detecting means 2 is used as the detecting means 13 immediately before the completion of boiling.
3, the control means for controlling the rotation speed of the compressor to be reduced when the temperature becomes equal to or higher than the predetermined lower temperature of the hot water storage tank 5 enables the hot water capacity of the hot water storage tank 5 to be used effectively.
Further, since the lower temperature of the hot water storage tank 5 is directly detected and controlled, the durability of the compressor is more reliably improved.

[0065]

As described above, according to the first to ninth aspects of the present invention, when the completion of boiling is approached and the discharge pressure of the compressor rises, the rotational speed of the compressor with variable capacity is increased. Control, the discharge pressure is kept low, and the hot water supply heating operation can be performed up to the high water supply temperature.Therefore, there is less wasted area that cannot be used as effective hot water, so the hot water capacity of the hot water storage tank is effective. Available to 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.

[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 a graph showing a hot water supply operation state, a compressor rotation speed, a discharge pressure, and a water supply 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 a graph showing a discharge pressure with respect to a rotation speed of a compressor of the heat pump water heater.

FIG. 6 is a graph showing the detected temperature immediately before the completion of boiling and the amount of change in the number of revolutions of the compressor with respect to the outside air temperature 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 the state of hot water supply operation with respect to the operation time of the heat pump water heater, the number of rotations of the compressor, the discharge pressure, and the water supply temperature.

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 the rotation speed of the compressor and the discharge pressure with respect to the water supply temperature of the heat pump water heater.

FIG. 11 is a graph showing the amount of change in the number of revolutions of the compressor with respect to the water supply 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 a graph showing the discharge pressure, the number of revolutions of the compressor, and the feed water temperature with respect to the 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 a graph showing the discharge pressure, the number of revolutions of the compressor, and the feed water temperature with respect to the 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 a graph showing the number of revolutions of the compressor, the discharge pressure, the flow rate, the opening of the flow control valve, and the feed water temperature 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 a graph showing the rotation speed of the compressor, the discharge pressure, and the feed water temperature with respect to the operation time of the heat pump water heater.

FIG. 20 is a configuration diagram showing a heat pump water heater according to a ninth embodiment of the present invention.

FIG. 21 is a graph showing the state of hot water supply operation with respect to the operation time of the heat pump water heater, the rotation speed of the compressor, the discharge pressure, and the lower temperature of the hot water tank.

FIG. 22 is a configuration diagram showing a heat pump water heater in a conventional example.

FIG. 23 is an explanatory diagram showing a temperature distribution of a hot water storage tank of the heat pump water heater.

FIG. 24 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 just before completion of boiling

Claims (9)

[Claims] 1. A variable capacity compressor, a refrigerant-to-water heat exchanger,
A refrigerant circuit in which a pressure reducing device and an evaporator are sequentially connected; a hot water supply circuit in which a hot water tank, a circulation pump, and the refrigerant-to-water heat exchanger are sequentially connected; and a water-side outlet of the refrigerant-to-water heat exchanger in the hot water supply circuit. In order to keep the boiling temperature that is the water temperature constant between the water-side inlet of the refrigerant-to-water heat exchanger and the hot water storage tank, or, the water-side outlet of the refrigerant-to-water heat exchanger and the hot water storage tank, A flow control means for controlling a flow control valve provided between the first and second hot water storage tanks; 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 signal. A control means for controlling the rotation speed of the compressor to be reduced when the heat pump water heater is turned on. 2. The heat pump hot water supply according to claim 1, further comprising control means for determining the amount of change in the rotational speed of the compressor in accordance with the outside air temperature obtained from the outside air temperature detecting means for detecting the outside air temperature. Machine. 3. A water supply temperature detection means for detecting a water supply temperature which is a water-side inlet water temperature of a refrigerant-to-water heat exchanger as a detection means immediately before the completion of boiling, wherein the water supply temperature detection means comprises a plurality of predetermined water supply waters. 2. The heat pump water heater according to claim 1, further comprising control means for controlling so as to reduce the rotation speed of the compressor every time the temperature is detected. 4. The heat pump water heater according to claim 3, wherein the amount of change in the number of revolutions of the compressor is increased as the feedwater temperature is increased. 5. The heat pump water heater according to claim 1, further comprising control means for changing the rotation speed of the compressor at predetermined time intervals. 6. The heat pump water heater according to claim 5, wherein the time interval of the change in the number of revolutions of the compressor is reduced as the boiling is completed. 7. A time measuring means for calculating a time when the flow rate passing through the flow rate control valve reaches a maximum flow rate and calculating a time when the flow rate is the maximum flow rate is provided as a detection means immediately before completion of boiling. Item 2. The heat pump water heater according to Item 1. 8. The heat pump water heater according to claim 1, further comprising a discharge pressure detecting means as the detecting means immediately before the completion of the heating. 9. The heat pump water heater according to claim 1, further comprising 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.