JPS6232378B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump water heater equipped with a heat pump cycle heating device and a hot water storage tank equipped with an auxiliary heating device.
The purpose is to improve the reliability of heat pump cycles.

In the conventional method, the water in the hot water storage tank is forcedly circulated to the heating heat exchanger of the heat pump cycle to store the condensed heat of the heat pump, and the inlet water temperature of the heating heat exchanger is detected and switched to the auxiliary heating device. Although the water temperature in the hot water storage tank is sufficiently high during operation of the heating device, the inlet water temperature of the heating heat exchanger cannot be detected for some reason, for example,
When the temperature drops below a predetermined temperature due to a drop in outside air temperature, etc., heat pump operation is restarted, but since the actual temperature of the water circulated to the heating heat exchanger is high, heat pump operation is immediately stopped. If such a phenomenon occurs frequently, it may cause a failure of the heat pump cycle.

The present invention solves the above conventional problems by regulating the operation of the auxiliary heating device from returning to heat pump heating operation.

EMBODIMENT OF THE INVENTION Hereinafter, the present invention will be described in detail based on drawings showing one embodiment thereof.

FIG. 1 shows a system configuration diagram of a heat pump water heater according to an embodiment of the present invention. Heat pump cycle heating device 2
The compressor 3, the heating heat exchanger 4, the throttle mechanism 5, and the evaporator 6 are connected in an annular manner through a refrigerant piping line, and has a blower 7 for the evaporator 6. Further, the water in the hot water storage tank 1 is sent to the heating heat exchanger 4 by a circulation pump 9 disposed in a pipe 8 connecting the lower part of the hot water storage tank 1 and the inlet of the heating heat exchanger 4. 4, the hot water is heated to a raised temperature, passed through the hot water temperature adjustment mechanism 10 disposed at the outlet of the heating heat exchanger 4, and returned to the hot water tank 1 from the outlet pipe 11 at the top of the hot water storage tank 1. Hot water is stored sequentially. and again,
A hot water tap 11 is provided with a hot water supply pipe 12 and a hot water tap 13, and a safety valve 14 is provided at the top of the piping system. 15 is the water supply pipe,
This water supply pipe 15 is provided with a pressure reducing check valve 16 . Further, an electric heater 17 as an auxiliary heating device is provided at the lower part of the hot water storage tank, and this electric heater 17 is used to obtain a hot water temperature higher than the hot water temperature heated by the heat pump cycle heating device 2. . Reference numeral 18 denotes a temperature detection section that detects the inlet water temperature of the heating heat exchanger 4, and is attached to the pipe 8. Reference numeral 19 denotes a temperature detection section for detecting the temperature of hot water in the hot water tank 1, which is attached to the wall of the hot water tank 1 near the electric heater 17.

FIG. 2 shows an embodiment of the electric circuit of the present invention for controlling the operation of the system shown in FIG.
In this figure 2, 3 is a compressor, 7 is a blower,
9 is a circulation pump, 17 is an electric heater, 20 is an earth leakage breaker connected to a late-night power source, 21 is a power relay having three interlocking opening/closing contacts, 2
2 is a temperature detection unit 19 that detects the temperature of hot water in the hot water storage tank 1;
With the on/off contacts, you can vary the temperature setting as needed. A first thermostat 23 controls the operation of the heat pump, and this first thermostat 23 detects, for example, the outside temperature. 24 is a temperature detection unit 1 that detects the inlet water temperature of the heating heat exchanger 4
8 is the opening/closing contact, 25 is the first timer relay,
The first timer relay 25 is configured such that the coil is excited and the contact 25a thereof is opened after a certain period of time has elapsed after energization. Reference numeral 26 denotes a second timer relay, and the second timer relay 26 is configured such that its coil is excited and its contact 26a is closed after a certain period of time has elapsed after energization. 2
Reference numerals 7 and 28 denote a pressure detection contact and an overfire prevention contact, which are connected in parallel to the safety circuit of the earth leakage breaker 20, respectively.

To explain the operation of the circuit configuration shown in Fig. 2 above, when the late-night power 1φ200V is turned on,
The contact 25a of the first timer relay 25 is closed, and if the outside temperature is high enough for heat pump operation, the first thermostat 23
The contact 2 of the temperature detection unit 18 is closed, and if the temperature detected by the temperature detection unit 18 that detects the inlet water temperature of the heating heat exchanger 4 is lower than the set temperature, the opening/closing contact 2 of the temperature detection unit 18 is closed.
4 is also closed, so the power relay 21 is energized. This causes the first timer relay 2
5 is stopped, its contacts 25a remain closed, and at the same time the circulation pump 9 is driven and water is circulated to the heating heat exchanger 4, the second
The timer relay 26 is energized. The time setting of the second timer relay 26 is set to an appropriate time necessary for the heating heat exchanger 4 to be sufficiently cooled. When the set time of the second timer relay 26 has elapsed, the contact 26a is closed, and as a result, the compressor 3 and the blower 7 are respectively energized and heated in the heat pump heating operation. At this time, since the heating heat exchanger 4 is sufficiently cooled, the rise of the high pressure of the heat pump cycle becomes gradual, and an abnormal rise in the high pressure can be prevented. During the heat pump heating operation, the circulation pump 9 heats the water in the lower part of the hot water tank 1 through the heat exchanger 4.
The hot water temperature adjustment mechanism 10 is then heated to raise the temperature.
Since the water is returned from the top of the hot water storage tank 1 as a nearly constant hot water (approximately 55℃), a slight boundary layer is formed in the hot water storage tank 1, with cold water at the bottom and hot water at the top, and this boundary layer While pressing down, the water in the hot water tank 1 is boiled up to hot water. Since the temperature of the water circulated to the heating heat exchanger 4 is approximately constant until the boundary layer reaches the lower part of the hot water storage tank 1, the heat pump cycle can operate stably. Further, as the boundary layer is pushed down to the lower part of the hot water storage tank 1, the temperature of the water circulated to the heating heat exchanger 4 gradually rises, and the high pressure of the heat pump cycle rises. When this high pressure rises above a certain limit, not only the efficiency of the heat pump cycle decreases, but also the load on the compressor 3 increases, which may eventually cause a failure.

Therefore, the temperature detection section 18 attached to the pipe 8
detects a predetermined temperature and opens its contact 24, thereby returning the power relay 21 to the state shown in FIG. As a result, the power to the circulation pump 9, compressor 3, and blower 7 is cut off, and the heat pump operation is stopped.At the same time, the power relay 21
Since the back contact (the contact connected to the electric heater 17 and the first timer relay 25) is closed,
Electricity is supplied to the electric heater 17 and the first timer relay 25 as necessary. When the set time of the first timer relay 25 has elapsed, the coil is energized and its contact 25a is opened. Therefore,
Even if the temperature detection unit 18 that detects the inlet water temperature of the heating heat exchanger 4 detects a temperature below a predetermined temperature for some reason and its contact 24 closes, the contact 25a of the first timer relay 25 remains open. Therefore, the power relay 21 is not energized. That is, the contact 25a of the first timer relay 25 is
The circuit configuration connected in series to the excitation circuit of the power relay 21 forms a fixed switching circuit that restricts return to heat pump heating operation during heating operation by the auxiliary heating device of the electric heater 17. When the temperature of the hot water in the hot water storage tank 1 exceeds a predetermined value due to heating by the electric heater 17, the hot water temperature is detected by the hot water temperature detection unit 1.
9 is detected, its contact 22 is opened, and electricity supply to the electric heater 17 is stopped, and boiling is completed. At the same time, the power supply to the first timer relay 25 is also stopped, and its contact 25a is closed. However, since the inlet water temperature of the heating heat exchanger 4 is above the normal setting value at this point, the temperature detection section 1
The switching contact 24 of No. 8 is open, so the power relay 21 will not operate. If for some reason the temperature detection unit 18 that detects the inlet water temperature of the heating heat exchanger 4 detects a temperature below the set temperature and the opening/closing contact 24 closes, the power relay 2
1 is activated, the circulation pump 9 and the second timer relay 26 are energized, and the operation of the circulation pump 9 causes water to begin circulating from the lower part of the hot water storage tank 1 to the heating heat exchanger 4. When the water temperature at the bottom of the tank 1 is sufficiently higher than the set temperature of the temperature detection section 18, the opening/closing contact 24 of the temperature detection section 18 opens within the set time of the second timer relay 26.
The power relay 21 will return to the state shown in FIG. 2, and as a result, the compressor 3 will not start.

As described above, energy-saving operation is possible by giving priority to highly efficient heat pump heating operation using the power relay 21, and heating by the electric heater 17, which is an auxiliary heating device, as necessary after the heat pump heating operation is completed. In addition, since the heat pump and the electric heater 17 do not operate simultaneously, the power receiving capacity can be reduced.

In addition, by delaying the startup of the compressor 3 and the blower 7 using the timer relay 26 connected in parallel with the circulation pump 9, it is possible to prevent an abnormal rise in high pressure when the heat pump starts operating, and also to exchange heating heat. The inlet water temperature of the vessel 4 is detected by the temperature detection part 1.
If the temperature is sufficiently higher than the set temperature in step 8, the compressor 3 is not energized and switched to the electric heater 17, which prevents forced operation of the heat pump and improves the reliability of the heat pump.

Although the above embodiment has been described using the electric heater 17 as the auxiliary heating device, it is clear that the same effect can be obtained even if a heating device using kerosene, gas, etc. is used. .
In addition, the power supply is 1φ100V and late night power 1φ
Although the explanation has been made using 200V, it is obvious that any other power source may be used and the same effect can be obtained even if the control system is replaced with an electronic circuit.

As described above, the heat pump water heater of the present invention is equipped with a switching fixed circuit that restricts the return to heat pump operation during heating operation by the auxiliary heating device, so that the heat pump is frequently turned on and off.
OFF can be prevented, and as a result, the reliability of the heat pump cycle can be improved.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a heat pump water heater according to an embodiment of the present invention, and FIG. 2 is an electric circuit diagram of the same water heater. 1... Hot water storage tank, 2... Heat pump cycle heating device, 3... Compressor, 4... Heating heat exchanger, 5
... Throttle mechanism, 6... Evaporator, 7... Air blower, 8
... Inlet water pipe of heating heat exchanger 4, 9 ... Circulation pump, 17 ... Electric heater as auxiliary heating device, 21 ... Power relay, 25 ... First timer relay (switching fixed circuit).

Claims (1)

[Scope of Claims] 1. A heat pump cycle heating device comprising a compressor, a heating heat exchanger, a throttle mechanism, and an evaporator connected through an annular refrigerant piping line, and a hot water storage tank equipped with an auxiliary heating device. , in a heat pump water heater in which water in the hot water storage tank is forcibly circulated by a circulation pump and heated by the heating heat exchanger, after the heat pump heating operation is completed, the water is switched to the auxiliary heating device as necessary, and the heating by the auxiliary heating device is performed. A heat pump water heater characterized in that it is equipped with a fixed switching circuit that restricts return to heat pump heating operation during operation. 2 After the heating operation by the auxiliary heating device is completed,
The heat pump water heater according to claim 1, wherein the switching fixed circuit is released.