JPH05272812A - Heat pump type hot water feeder - Google Patents

Abstract

(57) [Summary] [Purpose] The present invention relates to a hot water storage type hot pump water heater, which prevents a decrease in hot water temperature during hot water discharge and a decrease in hot water temperature in a hot water storage tank during freeze prevention operation and defrost operation. [Structure] A hot water heat exchanger 3 and a hot water storage tank 7, a water supply circuit 9 via a pump 8, and a hot water discharge pipe 1 provided at the top of the hot water storage tank 7.
The hot water supply circuit 11 via 0 is connected. A three-way valve 17 is provided in the hot water supply circuit 11 and near the connection portion of the hot water supply pipe 10, and the branch of the three-way valve 17 and the lower part of the hot water storage tank 7 are connected by a water discharge circuit 18. Then, the flow rate detector 19 and the water supply circuit 9 are connected to the tap pipe 10.
A water supply temperature detector 13 and an evaporator 6 are provided with a frost detector 14. In addition, the three-way valve 17, by the signal from each of the detectors,
A controller 20 for controlling the pump 8 and the four-way valve 2 is provided. The controller 20 controls the flow rate detector 19 during hot water discharge, the water temperature detector 13 during freeze prevention operation, and the frost detector 14 during defrost operation so that the hot water supply circuit 11 and the water discharge circuit 18 communicate with each other. By switching 17 the low temperature water is guided to the lower part inside the hot water storage tank 7 by the water discharge circuit 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage type heat pump water heater.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional heat pump water heater comprises a compressor 1, a four-way valve 2, a heat exchanger 3 for hot water, a throttle mechanism 5 provided with a check valve 4 in parallel, and an evaporator 6. A heat pump cycle formed by coupling with an annular refrigerant pipe, a water supply circuit 9 from the lowermost portion of the hot water storage tank 7 to the heat exchanger 3 for hot water via the pump 8, and the heat exchanger 3 for hot water to the hot water storage tank 7 The hot water storage circuit 7 is connected to the heat pump cycle by the hot water supply circuit 11 that reaches the hot water outlet pipe 10 provided at the uppermost part. Further, 12 is a water temperature detector for detecting the water temperature in the hot water supply circuit 11, and 13 is a water supply temperature detector for detecting the water temperature in the water supply circuit 9. 14 is a frosting detector provided in the evaporator 6,
Reference numeral 15 is a blower. Reference numeral 16 is a water supply pipe provided in the hot water storage tank 7.

In the above structure, the operation of the heat pump cycle will be described first. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 enters the hot water heat exchanger 3 through the four-way valve 2. The gas refrigerant in the hot water heat exchanger 3 exchanges heat with the water sent from the hot water storage tank 7 through the water supply circuit 9 and the pump 8, and gives heat to the water to be condensed to become a liquid refrigerant. Then, it enters the throttling mechanism 5 and is decompressed, and the evaporator 6 takes heat from the outside air sucked by the blower 15 to evaporate and become a gas refrigerant. The gas refrigerant returns to the compressor 1.

Next, the operation of the water circuit will be explained.
The water is sent from the lowermost part of the pump to the hot water heat exchanger 3 through the water supply circuit 9 to exchange heat with the high-temperature and high-pressure gas refrigerant to heat the water. The hot water passes through the hot water supply circuit 11 and the hot water outlet pipe 10 and flows into the upper portion of the hot water storage tank 7, and is sequentially stored from the upper portion. Here, the rotation speed of the pump 8 is controlled by the water temperature detector 12 to keep the hot water temperature at the outlet of the hot water heat exchanger 3 constant.

Further, in winter, after the equipment is stopped, in order to prevent the heat exchanger 3 for hot water, the pump 8, the water supply circuit 9, and the hot water supply circuit 11 from freezing, the temperature detected by the water supply temperature detector 13 becomes below a predetermined value. Then, the pump 8 is rotated to circulate water. Further, when the evaporator 6 is frosted during operation of the device in winter, the frost detector 14 switches the four-way valve 2 as shown by the dotted line in the figure, and the gas refrigerant enters the evaporator 6 for defrosting and the check valve. The heat exchanger 3 for hot water enters from 4. At this time, the pump 8 is operated and the heat exchanger 3 for hot water acts as an evaporator. The refrigerant evaporated in the hot water heat exchanger 3 returns to the compressor 1. When the defrosting is completed, the four-way valve 2 is switched by the frosting detector 14 to return to the normal cycle.

[0006]

However, in the above-mentioned conventional configuration, when hot water in the hot water storage tank 7 is discharged from the hot water discharge pipe 10, low temperature water flows into the hot water storage tank 7 from the water supply pipe 16 and the low temperature water is discharged. However, there is a problem in that the water flows through the water supply circuit 9, the pump 8, the hot water heat exchanger 3, and the hot water supply circuit 11 into the hot water discharge pipe 10 to lower the hot water temperature.

In winter, when the pump 8 is operated to prevent freezing, the low temperature water in the hot water tank 7 is supplied with the water supply circuit 9,
After passing through the pump 8, the heat exchanger 3 for hot water, and the hot water supply circuit 11, the hot water flows into the hot water outlet pipe 10, and this action causes heat radiation to lower the temperature of the hot water stored in the hot water storage tank 7, and the defrosting operation. There was also the problem of lowering the temperature of the hot water as in the above.

The present invention has been made to solve the above problems, and an object of the present invention is to prevent the temperature of hot water from decreasing when tapping hot water and to prevent the temperature of hot water in the hot water tank 7 from decreasing during freeze prevention operation and defrosting operation. It is a thing.

[0009]

In order to achieve the above-mentioned object, the present invention provides a three-way valve in the hot water supply circuit and near the connection with the hot water outlet pipe, and branches from this three-way valve to the lower part of the hot water tank. A controller that controls the three-way valve, the pump, and the four-way valve by the signals from the above-mentioned outlet circuits, the flow rate detector in the hot water outlet pipe, the feed water temperature detector in the water supply circuit, and the frost detector in the evaporator. Is provided.

[0010]

According to the present invention, the flow rate detector is used when hot water is discharged, and the three-way valve is switched so that the hot water supply circuit and the water discharge circuit are communicated with each other.
The low-temperature water is stored in the water discharge circuit by controlling the pump to the minimum flow rate and switching the three-way valve in the same way as when tapping hot water, and by starting the defrosting operation by switching the four-way valve by the frost detector and the three-way valve as in hot water tapping. By guiding the water to the lower part of the bath, it is possible to prevent the temperature of the hot water from lowering during hot water discharge and to prevent the temperature of hot water in the hot water storage tank from decreasing during freeze prevention operation and defrosting operation.

[0011]

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

In FIG. 1, the same reference numerals as those in FIG. 4 denote the same members and have the same functions, and therefore, detailed description thereof will be omitted, and different points will be mainly described.

In FIG. 1, reference numeral 17 denotes a three-way valve provided in the hot water supply circuit 11 and near the connection with the hot water supply pipe 10.
Reference numeral 8 is a water discharge circuit branched from the three-way valve 17 and connected to the lower portion of the hot water storage tank 7, and 19 is a flow rate detector provided in the hot water discharge pipe 10. Reference numeral 20 is a controller for controlling the three-way valve 17, the pump 8 and the four-way valve 2 as will be described later on the basis of signals from the flow rate detector 19, the feed water temperature detector 13, and the frost detector 14.

The operation of the above configuration is shown in FIGS.
The control flow will be described. The operation after the device is stopped will be described with reference to FIG. 2. First, the flow rate detector 19 determines whether hot water is being discharged, and if hot water is not discharged, the three-way valve 17 is closed to bring the hot water supply circuit 11 and the hot water pipe 10 into a communication state,
On the contrary, if hot water is flowing in the hot water supply pipe 10, the flow rate detector 19 is activated, the three-way valve 17 is opened, the hot water supply circuit 11 is disconnected from the hot water supply pipe 10, and the hot water supply circuit 18 is communicated. The low-temperature water that has flowed to the circuit 11 is the water discharge circuit 1
It will be returned to the lower part of the hot water storage tank 7 via 8. Next, the feed water temperature detector 13 determines whether the antifreezing operation is necessary. The temperature detected by the water temperature sensor 13 and T _1, the temperature required freeze prevention operation and T _S, T _1> T if _S pump 8 remains stopped three-way valve 17 before leaving water determination The state (open / closed state) continues. On the contrary, if T ₁ <T _S , the pump 8 is driven at the minimum flow rate, and the three-way valve 17 is opened unless hot water is being discharged at this time. Then, in the hot water discharge state, the three-way valve 17 is kept open, and the low temperature water is returned to the lower part of the hot water storage tank 7 through the water discharge circuit 18 as described above.

The defrosting operation during the operation of the equipment will be described with reference to FIG.
It is judged whether there is frost on the four-way valve 2
Is closed (solid line in FIG. 1), the three-way valve 17 is closed.
On the contrary, if frost is formed, the four-way valve 2 is opened by the frost detector 14 (dotted line in FIG. 1) and the three-way valve 17 is opened to defrost the frost adhering to the evaporator 6. to go into. When the frost attached to the evaporator 6 is completely defrosted by the defrosting operation, the four-way valve 2 is closed by the frost detector 14 (solid line in FIG. 1).
The three-way valve 17 is closed and the normal operation is restored. The above operation is performed by the controller 20.

According to the construction of this embodiment, the hot water supply circuit 11 is switched from the hot water supply pipe 10 by connecting the hot water supply circuit 11 by switching the three-way valve 17 at the time of hot water discharge. Therefore, it is possible to prevent the hot water mixing in the hot water discharge pipe 10 and prevent the decrease of the hot water temperature. Similarly to the above, during the anti-freezing operation and the defrosting operation, the three-way valve 17 is switched and the low temperature water is guided to the lower part of the hot water storage tank 7 by the water discharge circuit 18 to prevent the temperature of the hot water in the hot water storage tank 7 from decreasing.

[0017]

As described above, the heat pump hot water supply apparatus of the present invention is provided with a three-way valve in the hot water supply circuit and near the connection with the hot water outlet pipe, and a water discharge circuit that branches from this three-way valve to reach the lower part of the hot water tank. A flow rate detector on the hot water supply pipe, a feed water temperature detector on the water supply circuit, a frost detector on the evaporator, and a controller for controlling the three-way valve, the pump and the four-way valve according to the signals from the detectors. When tapping hot water, the flow detector switches the three-way valve so that the hot water supply circuit and the tap water circuit communicate with each other, and during freeze prevention operation, the feed water temperature detector controls the pump to the minimum flow rate and switches the three-way valve as when tapping hot water. At the start of the defrosting operation, the frosting detector controls the switching of the four-way valve and the three-way valve in the same manner as when tapping hot water, and the above-mentioned controller controls the cold water to the lower part of the hot water storage tank by means of a water discharge pipe.

As a result, it is possible to prevent lowering of the hot water temperature when the hot water is discharged, and to prevent lowering of the hot water temperature in the hot water storage tank during the antifreezing operation and the defrosting operation.

[Brief description of drawings]

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

FIG. 2 is a control flow chart during hot water discharge and freeze prevention operation of FIG.

FIG. 3 is a control flowchart of the defrosting operation of FIG.

FIG. 4 is a circuit configuration diagram of a conventional heat pump water heater.

[Explanation of symbols]

 1 Compressor 2 Four-way valve 3 Heat exchanger for hot water 4 Check valve 5 Throttle mechanism 6 Evaporator 7 Hot water storage tank 8 Pump 9 Water supply circuit 10 Hot water supply pipe 11 Hot water supply circuit 13 Water temperature detector 14 Frost detector 17 Three-way valve 18 Water discharge circuit 19 Flow rate detector 20 Controller

Claims (2)

[Claims] 1. A compressor, a four-way valve, a heat exchanger for hot water, a throttle mechanism provided with a check valve in parallel, a heat pump formed by connecting an evaporator with an annular refrigerant pipe, and a pump from the bottom of a hot water storage tank. A water supply circuit leading to the heat exchanger for hot water via the hot water supply circuit, a hot water supply circuit extending from the heat exchanger for hot water to the hot water discharge pipe provided at the top of the hot water storage tank, and a water supply circuit provided near the connection part with the hot water discharge pipe. A three-way valve, a water outlet circuit that branches from the three-way valve to the bottom of the hot water tank, a flow rate detector in the hot water outlet pipe, a water temperature detector in the water supply circuit,
A heat pump hot water supply apparatus comprising an evaporator provided with a frosting detector, and a controller for controlling a three-way valve, a pump, and a four-way valve according to signals from the detectors. 2. When the flow rate detector is operating, the three-way valve is switched so that the hot water supply circuit and the water discharge circuit are in communication with each other, and when the water temperature detector is operating, the pump is controlled to the minimum flow rate and the three-way valve is operated in the same manner as when the flow rate detector is operating. A controller for switching the valve and switching the three-way valve and the four-way valve when the frost detector is activated.
The heat pump water heater described.