JPH0260950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat pump water heater.

Conventional structure and its problems Conventionally, this type of heat pump water heater is shown in Figure 1.
The structure is as shown in Figure 2. In FIG. 1, 1 is a compressor, 2 is a condenser, 3 is an expansion valve, 4 is an evaporator, 5 is a heat source blower, and 6 is an accumulator, which constitute a refrigerant circuit of an air source heat pump. Further, 7 is a hot water storage tank, 8 is a water circulation outgoing pipe from the hot water storage tank 7 to the condenser 2 via a pump 9, 10 is an auxiliary heater disposed downstream of the condenser 2, and 11 is a condenser. 2 is a water circulation return pipe that flows into the upper part of the hot water storage tank 7 via the auxiliary heater 10.
12 is a hot water outlet pipe branched from the water circulation return pipe 11, and 13 is a water supply pipe. 14 is a temperature sensor that detects the hot water flowing into the hot water storage tank 7, which changes the number of revolutions of the pump and controls the amount of circulating water, so that the hot water tank This is to store hot water while keeping the temperature of the hot water flowing into the tank constant.

According to this configuration, when hot water is stored in the hot water storage tank 7, the heat pump and the pump are operated to heat the circulating water from the lower part of the hot water storage tank 7 in the condenser 2, convert it into hot water, and flow it into the top part to store hot water. When the outside temperature is low, such as in winter, the heating capacity of the condenser 2 decreases, resulting in insufficient capacity to guarantee hot water supply. In such a case, the auxiliary heater 10 is also operated. Also, even in winter, when the outside temperature is low and the humidity is relatively high, the evaporator 4
Frost forms on the evaporator 4 and the capacity of the evaporator 4 decreases, making efficient operation difficult. To prevent this, as shown in FIG. 2, the temperature at the outlet of the evaporator 4 is detected by the temperature detector 15, the solenoid valve 17 in the defrosting circuit 16 is opened, and the heat source blower 5 is stopped. The high temperature and high pressure gas refrigerant compressed by the compressor 1 is transferred to the evaporator 4.
to defrost. When defrosting is finished, solenoid valve 1
7 is closed and the heat source blower 5 is operated for normal operation. During defrosting, most of the refrigerant is in the evaporator 4.
Since the flow does not flow into the condenser 2, only the auxiliary heater 10 is operated during heating operation, resulting in insufficient heating capacity. In addition, since the rotation speed of the pump 9 is controlled by the temperature sensor 14, in order to obtain a predetermined temperature when the heating capacity decreases, the rotation speed of the pump must be extremely reduced, making control extremely difficult. It was hot. Particularly in the case of water heaters that use deep liquid electricity to boil water within a certain period of time, there is a problem in that it is not possible to secure a specified amount of water to a specified temperature.

OBJECTS OF THE INVENTION The present invention solves these conventional problems, and aims to provide a heat pump hot water supply device that ensures a predetermined heating capacity during defrosting and has high controllability.

Structure of the Invention In order to achieve this object, the present invention provides an auxiliary heater with a heating input control mechanism, and also includes a temperature difference detector that detects a temperature difference on the water side of the condenser and controls the input control mechanism. It is something that

With this configuration, during defrosting, when refrigerant does not flow to the condenser and the condenser does not function, the temperature difference detector detects the temperature difference between the water side entrance and exit of the condenser and controls the input of the auxiliary heater. The input control mechanism maximizes the auxiliary heater input. After defrosting, refrigerant flows into the condenser, and if a temperature difference occurs between the water side inlet and outlet of the condenser, the input control mechanism suppresses the input to the auxiliary heater.

This makes it possible to maintain the specified hot water supply temperature even during defrosting, cover the delay in boiling time due to defrosting time, and boil a specified amount to a specified temperature within a certain amount of time. Pump controllability is also improved because the pump rotation speed during frost can be controlled without drastically reducing it.

DESCRIPTION OF EMBODIMENTS The structure of an embodiment of the present invention will be described below with reference to FIGS. 3 and 4. Note that the same numbers as in FIGS. 1 and 2 indicate the same members.

In FIG. 3, 18 is a temperature difference detector that detects the temperature difference between the water side entrance and exit of the condenser 2, and 19 is an auxiliary first heater provided in the auxiliary heater 10'.
The first heater 19 is operated by an outside temperature sensor 20. Reference numeral 21 denotes an auxiliary second heater provided in the auxiliary heater 10, and the second heater 21 is turned on and off via a relay 22 in response to a signal from the temperature difference detector 18.

FIG. 4 shows an electric circuit diagram of the water side of the present invention, in which a temperature difference detector 18 is connected in parallel between the power supply lines 23 and 24.
A coil 25 of a relay 22 is connected in series with the temperature difference detector 18.
has been established. Similarly, an auxiliary second heater 21 is provided in parallel between the power lines 23 and 24, and a contact 26 of a relay 22 is provided in series with the second heater 21, and an auxiliary first heater 19 is similarly provided in parallel with the first heater 19. An outside temperature sensor 20 is provided. Contact point 26
is turned on and off by the coil 25. Similarly, a temperature sensor 14 is connected between the power lines 23 and 24, and a pump controller 27 and a pump 9 are connected in series with the temperature sensor 14.
has been established.

Next, to explain the operation, in hot water supply operation at medium to high outside temperatures, water is sent from the lower part of the hot water storage tank 7 via the pump 9 to the condenser 2 through the water circulation outgoing pipe 8.
It exchanges heat with the high-temperature, high-pressure gas refrigerant sent from the compressor 1, becomes high-temperature water, and passes through the auxiliary heater 10'.
The hot water is led to the upper part of the hot water storage tank 7 by a water circulation return pipe 11 and is stored in sequence. Here, the auxiliary heater 1 is detected by the temperature sensor 14.
The rotation speed of the pump 9 is controlled by the pump controller 27 so that the water temperature at the 0' outlet is constant.

At this time, neither the first auxiliary heater nor the second auxiliary heater 19, 21 is energized. Next, as in winter, the outside temperature drops,
When the temperature falls below the set temperature of the outside air temperature sensor 20, the auxiliary first heater 19 is turned on to compensate for the lack of heating capacity in the condenser 2 due to the drop in outside air temperature. Furthermore, if the outside air humidity is relatively high and frost forms on the evaporator 4, the temperature at the outlet of the evaporator 4 is detected by the temperature detector 15, the solenoid valve 17 in the defrosting circuit 16 is opened, and the compressor The refrigerant discharge gas of No. 1 is led to the inlet of the evaporator 4 to melt the frost attached to the evaporator 4. Further, the heat source blower 5 is in an off state. At this time, since no refrigerant flows to the condenser 2 side, heating operation is not performed, and the temperature difference between the water side entrance and exit of the condenser 2 becomes small, the temperature difference detector 18 works, and the coil 25 of the relay 22 is energized. 25 turns on the contact 26, and the auxiliary second heater 21 is energized. Therefore, during defrosting, the auxiliary first and second heaters 19,
21, a heating operation is performed. When defrosting is completed, the solenoid valve 17 is closed and the heat source blower 5 is operated to perform normal heating operation. Here, all of the gas refrigerant discharged from the compressor 1 flows into the condenser 2 and a temperature difference is created between the water side inlet and outlet, so the coil 25 of the relay 22 is turned off by the temperature difference detector 18, and the contact 26 is opened and the auxiliary second heater is turned off. 21 is turned off. At this time, the auxiliary first heater 19 is in the on state.

In this way, when the refrigerant does not flow into the condenser 2 during defrosting and the condenser 2 does not function, the temperature difference between the water side entrance and exit of the condenser 2 is detected by the temperature difference detector 18, and the relay coil 25 and contact By turning on the auxiliary second heater 21 via the auxiliary heater 26, the amount of heating by the auxiliary heater 10' can be ensured, and a predetermined hot water supply temperature can be obtained even during defrosting. It can cover time delays and boil a predetermined amount to a predetermined temperature within a certain amount of time.
In addition, compared to the conventional heating operation of the auxiliary heater 10 during defrosting, the capacity of the auxiliary heater 10' is increased and the rotation speed of the pump 9 can be controlled without extremely decreasing, so the controllability of the pump is improved. It also improves.

Effects of the Invention According to the heat pump water heater of the present invention, the following effects can be obtained.

(1) A heating input control mechanism is provided in the auxiliary heater, and a temperature difference detector is provided to detect the temperature difference on the water side of the condenser and control the input control mechanism, and when the condenser does not operate during defrosting, The input control mechanism of the auxiliary heater is controlled by the temperature difference detector to maximize the auxiliary heater input and ensure the specified hot water temperature even during defrosting, thereby covering the delay in boiling time due to the defrosting time. A predetermined amount can be boiled to a predetermined temperature within a predetermined amount of time.

(2) Compared to the conventional heating operation of the auxiliary heater during defrosting, the heating capacity of the auxiliary heater is increased, so the pump rotation speed can be controlled without drastically decreasing, and the controllability of the pump is also improved. improves.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional heat pump water heater, Fig. 2 is a block diagram of another conventional heat pump water heater, Fig. 3 is a block diagram of a heat pump water heater according to an embodiment of the present invention, and Fig. 4 is a block diagram of a heat pump water heater according to an embodiment of the present invention. It is an electric circuit diagram of the same heat pump water heater. 1... Compressor, 2... Condenser, 3... Throttle mechanism, 4... Evaporator, 7... Hot water storage tank, 8, 11...
Water circulation circuit (water circulation, forward and return pipes), 10'... Auxiliary heater, 18... Temperature difference detector, 22... Heating input control mechanism (relay).

Claims (1)

[Claims] 1 The condenser and hot water storage tank of a heat pump, which consists of a compressor, a condenser, a throttling mechanism, and an evaporator connected through an annular refrigerant pipe, and a defrosting circuit that runs from the compressor discharge to the evaporator inlet via a solenoid valve. are connected by a water circulation circuit, and an auxiliary heater having a heating input control mechanism is disposed downstream of the condenser in the water circulation circuit, and a temperature difference on the water side of the condenser is detected to control the heating input control mechanism. A heat pump water heater equipped with a temperature difference detector to control the temperature.