JPS6129649A - Heat-pump hot-water supply device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a heat pump water heater.

Conventional Structure and Problems Conventionally, this type of heat pump water heater is shown in FIGS. 1 and 2. In Figure 1, 1 is a compressor, 2
1 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 the air source heat pump. Also, 7 is a hot water tank, 8
1 is a water circulation outgoing pipe leading from the hot water storage tank 7 to the condenser 2 via the pump 9, 10 is an auxiliary heater disposed downstream of the condenser 2, and 11 is an auxiliary heater 10 located downstream of the condenser 2. This is a return pipe for water circulation that flows into the upper part of the hot water tank 7 through the water tank.

12 is a hot water outlet pipe branched from the water circulation return pipe 11;
13 is a water supply pipe. 14 is a temperature detector that detects hot water flowing into the hot water storage tank 7, which changes the rotation speed of the pump and controls the amount of circulating water when the heat pump is operating independently.
When operated in combination with the auxiliary heater, hot water is stored while keeping the temperature of hot water flowing into the hot water storage tank 7 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, and the circulating water from the lower part of the hot water storage tank 7 is heated by the condenser 2, and the hot water is made to flow into the top and stored. . 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. Furthermore, even in winter, when the outside temperature is low and the humidity is relatively high, frost forms on the evaporator 4, reducing the capacity of the evaporator 4, making it difficult to operate efficiently. In order 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. Then, the high-temperature, high-pressure gas refrigerant compressed by the compressor 1 is guided to the evaporator 4 for defrosting. When defrosting is completed, the solenoid valve 17 is closed and the heat source blower 5 is operated for normal operation. During defrosting, most of the refrigerant flows to the evaporator 4 and does not flow to the condenser 2, so only the auxiliary heater 10 is operated during the 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 difficult. Particularly in the case of a late-night electric water heater that boils water within a certain period of time, there is a problem in that it is not possible to ensure a specified amount of water up 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 To achieve this object, the present invention provides an auxiliary heater with a heating input control mechanism and 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 the refrigerant does not flow to the condenser and the condenser does not function, the temperature difference between the water side entrance and exit of the condenser is detected by the temperature difference detector, and the input control mechanism of the auxiliary heater is activated. and maximize the auxiliary heater input through the input control mechanism. 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 a predetermined hot water supply temperature even during defrosting, and to compensate for the delay in boiling time caused by the defrosting time, making it possible to boil a predetermined amount to a predetermined temperature within a certain amount of time. The controllability of the pump is also improved because the pump rotation speed can be controlled without drastically reducing it.

DESCRIPTION OF THE 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 inlet and outlet of the condenser 2, and 19 is the auxiliary heater 10'.
an auxiliary first heater provided within the first heater 19;
is activated by the 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 a water-〇 electrical circuit diagram of the present invention, in which a temperature difference detector 18 and a temperature difference detector 18 are connected in parallel between power lines 23 and 24.
A coil 25 of a relay 22 is provided in series with the relay 22. Similarly, the auxiliary second heater 21 is connected in parallel between the power lines 23 and 24,
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, and an outside temperature sensor 20 is provided in series with the first heater 19. Contact 26
is turned off by the coil 25. Similarly, a temperature detector 14 is provided between the power lines 23 and 24, and a pump controller 27 and a pump 9 are provided in series with the temperature sensor 14.

Next, to explain the operation, during hot water supply operation at medium to high outside temperatures, water is circulated from the lower part of the hot water storage tank 7 via the pump 9 to the outgoing pipe 8.
The water is sent to the condenser 2, where it exchanges heat with the high-temperature, high-pressure gas refrigerant sent from the compressor 1. 7. The water is led to the northern part and stored in sequence. Here, the rotation speed of the pump 9 is controlled by the pump controller 27 so that the temperature of the hot water at the outlet of the auxiliary heater 10' is kept constant by the temperature sensor 4.

At this time, neither the auxiliary cylinder 1 nor the second heater 19.21 is energized. Next, when the outside temperature drops like in winter, the outside temperature sensor 2
When the temperature falls below the set temperature of 0, 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 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 from No. 1 is introduced into 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 the refrigerant does not flow 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 does not become small. When the coil 25 is energized, the contact 26 is turned on, and the auxiliary second heater 21 is energized. Therefore, during defrosting, the auxiliary first and second heaters 19.
211C) 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 the gas refrigerant discharged from the compressor 1 flows into the condenser 2, creating a temperature difference between the inlet and outlet on the water side.
Temperature difference detection? i? According to r18 I) relay 22 carp) v
25 is turned off, the contact 26 is opened, and the auxiliary second heater 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 2
By turning on the auxiliary second heater 21 via 6,
By ensuring the amount of heating by the auxiliary heater 10', it is possible to obtain the specified hot water supply temperature even during defrosting, and to compensate for the delay in boiling time due to the defrosting time, it is possible to supply the specified amount within a certain amount of time. You can do this by boiling it up to a certain temperature. 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 input to the auxiliary heater and maintain the specified hot water temperature even during defrosting, thereby delaying the boiling time due to the defrosting time. It is possible to boil a predetermined amount to a predetermined temperature within a certain 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 drawings]

Figure 1 shows the h″44 configuration of a conventional heat pump water heater.
FIG. 3 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 an electric circuit diagram of the same heat pump water heater. 1... Compressor, 2... Condenser, 3... Throttle groove, 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] A compressor, a condenser, a throttle mechanism, and an evaporator are connected by an annular refrigerant pipe, and the condenser and hot water storage tank of a heat pump are comprised of a defrosting circuit that connects a compressor discharge to an 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 for control.