JP2743704B2 - Heat pump water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater using a heat pump, which achieves higher efficiency, shorter boiling time and smaller size.

[0002]

2. Description of the Related Art Conventionally, a water heater using a heat pump is shown in FIG.
As shown in the figure, a refrigerant circuit including a compressor 21, a refrigerant-to-water heat exchanger 23, a pressure reducing device 24, and an evaporator 25, a hot water storage tank 26 having a heater 29 for boiling water therein, and the refrigerant-to-water heat exchanger And a high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 21 flows into the refrigerant-to-water heat exchanger 23, where the heat of condensation is used to generate the circulation pump 27. Heats the water sent from. Then, the hot water having a high temperature is stored in the hot water storage tank 26. On the other hand, the condensed and liquefied refrigerant is depressurized by the decompression device 24,
It flows into the evaporator 25. Then, it absorbs atmospheric heat to evaporate and gaseous, and returns to the compressor 21.

[0003]

However, in the above configuration, when the heater 29 and the heat pump are operated in combination, the water temperature in the hot water storage tank 26 rises uniformly as shown in FIG. Therefore, the heated water flows into the refrigerant-to-water heat exchanger 23 via the circulation pump 27. Therefore, in order to secure the heat exchange amount in the refrigerant-to-water heat exchanger 23, the pressure of the refrigerant circuit increases. That is,
The discharge pressure of the compressor 21 will rise abnormally,
The reliability of the equipment such as the temperature of the compressor motor is an issue. Therefore, the time for the heat pump alone operation is reduced, and the efficiency of the entire system is reduced. It is also possible to boil the inside of the hot water storage tank 29 by an efficient heat pump operation and further boil the heater alone to a high temperature, but in this case, the operation time becomes long. Alternatively, the heater capacity must be increased to boil it in a short time. Therefore, the size of the device is increased and the cost is increased.

[0004] The present invention solves the above-mentioned conventional problems, and aims at efficient operation, reduction of boiling time, and downsizing of equipment.

[0005]

In order to solve the above-mentioned problems, the present invention provides a refrigerant circuit in which a compressor, a four-way valve, a refrigerant-to-water heat exchanger, a pressure reducing device, and an evaporator are sequentially connected;
A water heater having a refrigerant-to-water heat exchanger, a water heater having a heater, a hot water supply circuit in which a lower part is connected to the water circulating pump and an upper part connected to the water heater in the order of a hot water tank, and an amount of water in the hot water tank High
Hot water level detection that detects the water temperature at a position approximately in the middle in the vertical direction
An alarm device, a first temperature detector provided at a lower part of the hot water tank or at a water passage inlet of the water circulation pump, and a control unit, wherein the control unit detects the predetermined temperature by the hot water amount detector.
Until the compressor is operated independently until the hot water level detector
When the temperature is detected, both the compressor and the water heater
Operation, and the first temperature detector is operated at a predetermined temperature.
Is detected, the compressor is stopped and the heater
The control is switched to the single operation of the heater .

[0006]

According to the present invention, there is provided a hot water detector having the above structure.
Detects that no increased to a constant temperature by a single compressor
Germany operated to heat the water through the refrigerant-water heat exchanger, heating
Hot water is stored from the top of the hot water storage tank through a water heater that is not energized . Then, the amount of hot water in the hot water tank increases with the operation time, and when the temperature of the hot water that has risen due to the operation of the compressor reaches the position of the hot water amount detector, the temperature of the hot water amount detector detects the temperature.
The heater of the water heater is energized, and the hot water flowing out of the refrigerant-to-water heat exchanger is further heated to a high temperature and stored in the upper part of the hot water storage tank. Then, when the hot water whose temperature has risen during the single operation of the compressor reaches the lower part of the hot water storage tank, the operation of the compressor is stopped by detecting the temperature of the first temperature detector, and the water heater energized to the heater is stopped.
And to perform a single operation of the heat sink, together make the most efficient heat-pump operation, and heat-pump operation
Alone heater pressurizes the highest water temperature that can not for example about 90 ° C. The
It is achieved by heat, and it is possible to improve economic efficiency , shorten boiling time and downsize equipment (reduction of heater capacity, etc.).
You . Also, place the hot water detector in the height direction of the water volume in the hot water tank.
By detecting the water temperature at a position approximately in the middle,
The initial compressor was not affected by the turbulence in the hot water temperature above the hot water tank.
Combined operation of the water heater and the compressor and the heater
Switching to power operation can be performed reliably.
And the compressor alone to approximately half the amount of water in the hot water tank
At the stage where hot water (for example, about 65 ° C) is obtained during operation, the compressor
Operates a water heater energized to the heater while continuing the operation of
From the top of the hot water tank
Storing starts and the lower half of the hot water tank is
Compressor operation and heater energization until filled with hot water
By continuing the operation of the water heater
Can improve heat resistance and shorten boiling time.
You.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, 1 is a compressor, 2 is a four-way valve,
3 is a refrigerant-to-water heat exchanger, 4 is a decompression device, and 5 is an evaporator. The compressor 1, the four-way valve 2, the refrigerant-to-water heat exchanger 3, the decompression device 4, and the evaporator 5 are sequentially arranged. They are connected to form a refrigerant closed circuit. 6 is a hot water storage tank, 7 is a variable-speed water circulation pump, 8 is a water heater having a heater 9, and the hot-water storage tank 6, the variable-speed water circulation pump 7, and the water heater 8 are sequentially connected. And constitute a hot water supply circuit. Reference numeral 10 denotes a first temperature detector, which is located at a lower portion of the hot water storage tank 6 or at a water passage inlet of the water circulation pump 7, and 11 is a second temperature detector, which is at a water passage outlet of the refrigerant-to-water heat exchanger 3. , 12 denotes a third temperature detector, are respectively provided on the water outlet side of the water heater 8. Reference numeral 13 denotes a hot water level detector, which is substantially intermediate in the height direction of the water volume in the hot water storage tank 6 .
The hot water tank 6 is provided to detect the water temperature of the section . The control unit 14 controls the energization of the compressor 1 or the heater 9 by detecting the temperature of the first temperature detector 10. The control unit 14 controls the rotation speed of the water pump 9 by detecting the temperatures of the second temperature detector 11 and the third temperature detector 12, and energizes the compressor 1 by detecting the temperature of the hot water detector 13. Control.

First, the operation of boiling water in the hot water storage tank 6 from a low temperature will be described. Hot water detector
13 compressor 1s are operated by the controller 14 and detects the cold temperature (e.g., 20 ° C.). The high-temperature and high-pressure refrigerant gas compressed by the compressor 1 flows into the refrigerant-to-water heat exchanger 3 and heats the water sent through the water circulation pump 7 by a condensing action. Then, the condensed and liquefied refrigerant is decompressed by the decompression device 4, flows into the evaporator 5, absorbs atmospheric heat, evaporates and gasifies, and returns to the compressor 1. On the other hand, it is heated by the refrigerant-to-water heat exchanger 3 to a predetermined temperature (for example, 65
° C.) since the hot water passes through the water heater 8 is not energized to the heater 9, will be stored gradually from the upper portion of the hot water storage tank 6. Then, it is stored up to the position of the hot water detector 13.
When the temperature is detected, the controller 14 can use the water heater
The heater 9 is energized. In this case, since the compressor 1 is operating, the water heated by the refrigerant-to-water heat exchanger 3 is further heated to a high temperature (for example, 90 ° C.) by the water heater 8, and the hot water storage tank 6 is heated. It accumulated from the top.

Therefore, the water temperature in the hot water storage tank 6 is such that hot water of the highest temperature is stored in the upper portion, hot water in the middle portion of the compressor when the compressor is operated alone, and initial low temperature water in the lower portion. . The operation is continued until the high-temperature hot water in the intermediate portion is stored in the lower portion, and the high-temperature hot water is detected by the first temperature detector 10, and an operation stop signal is sent from the controller 14 to the compressor 1. Therefore, in this case, the high-temperature hot water flowing out of the hot water storage tank 6 passes through the refrigerant / water heat exchanger 3 and is heated to the highest temperature by the water heater 8 and stored in the upper part of the hot water storage tank 6. . FIG. 2 shows the hot water temperature distribution in the hot water storage tank 6 at this time. FIG. 2 shows the operation of the compressor 1 and the heater 9 and the upper part of the hot water tank.
Shows the distribution of boiling water temperature in the middle and lower hot water storage tanks 6.
doing. In addition, the hot water level detector 13 is set to a high water level in the hot water tank 6.
To detect the water temperature by
Is affected by the disturbance of the hot water temperature in the upper part of the hot water storage tank 6.
From the initial operation of the compressor 1 to the compressor 1 and the heater 9
Ensure switching to combined operation with energized water heater 8
It can be carried out. Furthermore, almost the upper half of the water in the hot water tank 6
Up to about 65 ° C high-temperature hot water in single operation of compressor 1
On the floor, while operating the compressor 1, heat the water heater 8.
Energize the hot water tank 9 and the maximum hot water temperature of about 90 ° C from the top of the hot water tank 6
Hot water storage is started, and the lower half of hot water tank 6 is operated by compressor 1.
Compressor until filled with hot water of about 65 ° C obtained by rolling
For combined operation of operation 1 and water heater 8 energized to heater 9
Therefore, economic efficiency can be improved by efficient heat pump operation.
Above and shorten the boiling time to the maximum hot water temperature of about 90 ° C
Can be compatible.

[0011]

As described above, the heat pump water heater according to the present invention comprises a refrigerant circuit in which a compressor, a four-way valve, a refrigerant-to-water heat exchanger, a pressure reducing device, and an evaporator are sequentially connected; a water circulation pump; A water heat exchanger, a water heater having a heater,
Connect the lower part to the water circulation pump and the upper part to the water heater
A hot water supply circuit sequentially connecting a savings tundish was, the hot water storage tank water
Of hot water to detect the temperature of water at almost the middle in the height direction
A first temperature detector provided at a lower portion of the hot water storage tank or at an inlet of a water passage of the water circulation pump, and a controller,
The control unit operates until the hot water detector detects a predetermined temperature.
Operates the compressor independently, and the hot water detector detects the predetermined temperature.
When detected, the combined operation of the compressor and the water heater energized to the heater
And the first temperature detector detects a predetermined temperature.
Water heater that turned off the compressor and turned on the heater
The one that independent operation to switching control, with leverage efficient heat-pump operation to maximize heat pump
The maximum hot water temperature of about 90 ° C, which cannot be
Achieved by heater heating to improve economic efficiency and reduce boiling time
And miniaturization of equipment (reduction of heater capacity, etc.)
it can. In addition, the hot water detector is positioned in the height direction of the water volume in the hot water tank.
By detecting the water temperature at approximately the middle of the
The initial temperature of the hot water tank 6
Water heating by energizing the compressor and heater from the compressor alone operation
Switching to combined operation of the heaters
In both cases, the compressor is further reduced to almost the upper half in the hot water tank.
For example, at the stage where hot water of about 65 ° C was obtained in the single operation of
The operation of the water heater that energized the heater while the
Storage of hot water with the maximum hot water temperature of about 90 ° C from the top of the hot water storage tank
And the lower half of the hot water tank was obtained by running the compressor.
Operate the compressor and turn on the heater until it is filled with hot water.
By continuing the operation of the heated water heater,
Can improve heat resistance and shorten boiling time.
You.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a heat pump water heater according to one embodiment of the present invention.

FIG. 2 is a diagram of the temperature distribution of hot water in a hot water storage tank of the water heater.

FIG. 3 is a refrigerant circuit diagram of a conventional heat pump water heater.

FIG. 4 is a distribution diagram of the temperature of hot water in a hot water tank of a conventional heat pump water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Refrigerant-water heat exchanger 4 Decompression device 5 Evaporator 6 Hot water storage tank 7 Water circulation pump 8 Water heater 9 Heater 10 1st temperature detector 11 2nd temperature detector 12 3rd temperature detector 13 Hot water detector

Claims (1)

(57) [Claims] A refrigerant circuit in which a compressor, a four-way valve, a refrigerant-to-water heat exchanger, a pressure reducing device, and an evaporator are sequentially connected, a water circulation pump, the refrigerant-to-water heat exchanger, a water heater having a heater,
Connect the lower part to the water circulation pump and the upper part to the water heater
A hot water supply circuit sequentially connecting a savings tundish was, the hot water storage tank water
Of hot water to detect the temperature of water at almost the middle in the height direction
A first temperature detector provided at a lower portion of the hot water storage tank or at an inlet of a water passage of the water circulation pump, and a controller,
The control unit operates until the hot water detector detects a predetermined temperature.
Operates the compressor independently, and the hot water detector detects the predetermined temperature.
When detected, the combined operation of the compressor and the water heater energized to the heater
And the first temperature detector detects a predetermined temperature.
Water heater that turned off the compressor and turned on the heater
A heat pump water heater that controls to switch to single operation .