JP2004271102A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater capable of draining water in a hot water storage tank even when any of antifreezing heaters are not functioned to cause any of pipes to be frozen, free of breakage due to frozen water in the hot water storage tank, and highly reliable with lower cost. <P>SOLUTION: The heat pump water heater utilizing a heat pump cycle for boiling up hot water in the hot water storage tank comprises an outside air temperature sensor 30 for detecting the outside air, temperature antifreezing heaters 27a-27e, 28a-28c, 29a for heating pipe portions connected to the hot water storage tank 2, and a control part 13 for controlling the energization of the antifreezing heaters 27a-27e, 28a-28c, 29a in accordance with a temperature detected by the outside air temperature sensors 30. The antifreezing heaters 27a-27e, 28a-28c, 29a are mounted at least on individual pipes connected to the lower part of the hot water storage tank 2 so that the individual pipes are independently energized. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat pump water heater that uses a heat pump cycle to heat hot water into a hot water storage tank.
[0002]
[Prior art]
In conventional heat pump water heaters, if the heat pump hot water supply operation cannot maintain the hot water temperature due to equipment failure in winter, the water in the hot water storage tank may freeze, so circulation between the water heater main body and the heat pump main body may occur. By operating the pump to flow the water in the hot water storage tank, freezing was prevented even at a temperature lower than the freezing temperature. (For example, see Patent Document 1)
[0003]
[Patent Document 1]
JP-A-11-63661 (page 3-5, FIG. 2)
[0004]
[Problems to be solved by the invention]
As described above, conventional heat pump water heaters operate by operating the circulation pump to flow water in the hot water storage tank to prevent freezing.If the circulation pump breaks down, it becomes impossible to prevent freezing. The water in the water supply pipe or drain pipe connected to the lower part of the hot water storage tank or the circulation pipe with the heat pump body freezes, and the water in the hot water storage tank cannot be drained, and the hot water storage tank is damaged. There was a problem.
[0005]
The present invention has been made in order to solve the above problems, and even when freezing prevention cannot be performed, an inexpensive and highly reliable heat pump that does not break due to freezing in the hot water storage tank. It is an object of the present invention to provide a water heater.
[0006]
[Means for Solving the Problems]
A heat pump water heater according to the present invention includes a water heater body and a heat pump body as a heating source, and includes a hot water storage tank provided in the water heater body and a hot water storage heat exchanger provided in the heat pump body. A circulating circuit is formed by annularly connecting the cold water pipe and the hot water pipe to form a circulation circuit, and a circulation pump provided in the cold water pipe of the circulation circuit is operated to take out low-temperature water from the lower part of the hot water storage tank, and the heat pump is passed through the cold water pipe. A heat pump type water heater configured to send the hot water heated by the hot water storage heat exchanger to a hot water tank through the hot water pipe and return the hot water to an upper portion of the hot water storage tank. Or a temperature detecting means for detecting the internal temperature of the heat pump body, or the outside air temperature, or the temperature of the piping, and freezing for heating the piping connected to the hot water storage tank. Stopping heater, and control means for controlling energization to the anti-freezing heater based on the temperature detected by the temperature detecting means, wherein the anti-freezing heater is provided at least for each pipe connected to the lower part of the hot water storage tank. It is configured to be attached and to operate independently for each pipe.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a heat pump water heater according to Embodiment 1 of the present invention.
In FIG. 1, a hot water storage tank 2, a water supply pipe 3 connected to a lower portion of the hot water storage tank 2, a pressure reducing valve 4 provided in the water supply pipe 3, A hot water supply pipe 5 connected to the upper part of the water supply and a relief valve 6 are provided. The temperature sensor A7 is attached to the outer wall surface of the hot water storage tank 2 and detects the temperature of water in the hot water storage tank 2. The temperature sensor A7 is attached to a position having a predetermined capacity on the outer wall surface of the hot water storage tank 2, so that the amount of remaining hot water in the hot water storage tank 2 is also detected from the detected temperature at the mounting position. The heat pump body 8 is connected to upper and lower portions of the hot water storage tank 2 by a cold water pipe 9 and a hot water pipe 10 so as to form a circulation circuit. The circulation pump 11 is provided in the cold water pipe 9, and circulates water in the hot water storage tank 2 between the heat pump body 8 through the cold water pipe 9 and the hot water pipe 10. Further, a bypass pipe 26 connects the middle of the hot water pipe 10 and the upstream side of the circulation pump 11 of the cold water pipe 9 via a three-way valve 25 for antifreeze operation. The temperature sensor B12 detects a temperature for stopping the heating operation of the heat pump main body 8.
[0008]
The control unit 13 starts and stops the heating operation to the heat pump body 8 and the circulation pump 11 based on the detection values of the temperature sensors A7 and B12 and the input values from the operation unit 14 for setting the boiling temperature and the like. Control the operation of The water stopcock 15 is provided in the water supply pipe 3 and is opened and closed by manual operation. Further, the water stopcock 16 is provided in the drain pipe 17 and is also opened and closed by manual operation. The supply of water to the water supply pipe 3, the hot water supply pipe 4, the cold water pipe 9, the hot water pipe 10, and the drain pipe 17 connected to the hot water storage tank 2 is controlled independently for each pipe based on the temperature detected by the outside air temperature sensor C30. The antifreezing heaters 27a to 27e, 28a to 28c, 29a are mounted at appropriate places. The cold water pipe 9 is provided with an air vent plug 31 for discharging air accumulated in the circulation pump 11. Further, the water supply pipe 3 is provided with an emergency water tap 32 for taking out and using the water in the hot water storage tank 2 when the supply of tap water is stopped in a disaster or the like.
[0009]
FIG. 2 is a configuration diagram of the heat pump main body showing the first embodiment of the present invention.
In FIG. 2, the heat pump cycle of the heat pump main body 8 is configured by connecting a compressor 18, a hot-water storage heat exchanger 19, an expansion valve 20, an outdoor heat exchanger 21, and an accumulator 22 in order by a refrigerant pipe 23.
Here, a blower fan 24 is attached to the outdoor heat exchanger 21 to absorb heat, and the hot water storage heat exchanger 19 exchanges heat between the high-pressure gas refrigerant discharged from the compressor 18 and water for hot water supply. It has a refrigerant passage 19a through which the refrigerant flows and a hot water storage water passage 19b through which the hot water flows.
[0010]
In the heat pump water heater having the above configuration, the water supply into the hot water storage tank 2 is reduced by the pressure reducing valve 4 from the water supply pipe 3 to a constant pressure and filled. The water supplied into the hot water storage tank 2 is sent from the cold water pipe 9 to the heat pump body 8 by the circulation pump 11 and is heated. The heated hot water that has been heated to a high temperature is returned to the upper portion of the hot water storage tank 2 through the hot water pipe 10 and stored. The water in the hot water storage tank 2 expands when heated, and the expanded amount is discharged from the relief valve 6 to prevent the internal pressure of the hot water storage tank 2 from rising. A temperature sensor A7 attached to a predetermined position on the outer wall surface of the hot water storage tank 2 detects the temperature of the hot water in the hot water storage tank 2, and the control unit 13 receives a detection signal from the temperature sensor A7, and Judge the amount of hot water. The temperature sensor B12 detects the temperature of water passing through the cold water pipe 9 connected to the lower part of the hot water storage tank 2, and the control unit 13 receives the detection signal from the temperature sensor B11 and all the water in the hot water storage tank 2 is heated. When the determination is made, the heating operation of the heat pump body 8 is stopped.
[0011]
In winter, when the outside air temperature becomes 5 ° C. or less and there is a possibility that the piping may freeze, the temperature sensor C30 detects the outside air temperature at which there is a risk of freezing, and a heater for preventing freezing attached to each piping. Electricity is applied to 27a to 27e, 28a to 28c, and 29a to heat the pipes, thereby preventing freezing. Further, in order to prevent freezing of the cold water pipe 9 and the hot water pipe 10, the flow path is switched by the three-way valve 25 for freezing prevention operation, and the hot water storage of the cold water pipe 9 and the heat pump body 8 through the bypass pipe 26 without passing through the hot water storage tank 2. By circulating between the heat exchanger 19 and the hot water pipe 10 and heating with the heat pump main body 8, the cold water can be used without using hot water in the hot water storage tank 2 and without installing a separate anti-freezing heater. Freezing of the pipe 9 and the hot water pipe 10 can be prevented.
[0012]
FIG. 3 is a block diagram of a control circuit of the anti-freezing heater.
As shown in FIG. 3, the anti-freezing heaters 27a to 27e, 28a to 28c, and 29a are grouped for each pipe, and the energization is controlled. That is, energization to the freeze prevention heaters 27a to 27e attached to the water supply pipe 3 and the hot water supply pipe 5 is controlled as a first group, and a freeze prevention heater attached to the cold water pipe 9 and the hot water pipe 10 as a second group. The energization to 28a to 28c is controlled, and the energization to the anti-freezing heater 29a attached to the drain pipe 17 as a third group is controlled. These three groups of anti-freezing heaters are independently controlled by wiring in parallel or performing control separately. As a result, even if one of the freeze prevention heaters fails and the piping of the group freezes, if at least one of the other groups is functioning normally, the emergency intake water provided in the water supply piping 3 is provided. The water in the hot water storage tank 2 can be drained by opening one of the plug 32, the water stop valve 16 provided in the drain pipe 17 and the air vent plug 31 provided in the cold water pipe 9, and the water in the hot water storage tank 2 can be drained. Can be prevented from freezing and damaging the hot water storage tank 2.
[0013]
Therefore, according to the configuration shown in the first embodiment, according to the first embodiment, the anti-freezing heater is attached to each pipe connected to the lower part of the hot water storage tank 2, and By allowing the heaters to operate independently, even if some of the freeze prevention heaters do not function and some of the pipes are frozen, the water in the hot water storage tank 2 is discharged from other unfrozen pipes. It is possible to provide an inexpensive and highly reliable heat pump water heater that can drain water and does not damage the inside of the hot water storage tank 2 due to freezing.
[0014]
In the first embodiment, energization to the anti-freezing heater is controlled based on the outside air temperature detected by the outside air temperature sensor 30. However, the internal temperature of the water heater main body 1 and the heat pump main body 8, or The temperature of the water supply pipe 3, the cold water pipe 9, the drain pipe 17 and the like may be detected to control the energization to the anti-freezing heater.
[0015]
【The invention's effect】
As described above, according to the heat pump water heater according to the present invention, the water heater includes the water heater main body, the heat pump main body as a heating source, the hot water storage tank provided in the water heater main body, and the hot water storage provided in the heat pump main body. A heat exchanger and a cold water pipe and a hot water pipe are connected in a loop to form a circulation circuit, and a circulation pump provided in the cold water pipe of the circulation circuit is operated to take out low-temperature water from the lower part of the hot water storage tank, A heat pump water heater configured to send the hot water heated by the hot water storage heat exchanger to the hot water storage heat exchanger in the heat pump main body through the cold water pipe and return the hot water to the upper part of the hot water storage tank through the hot water pipe; , A temperature detecting means for detecting an internal temperature of the water heater main body or the heat pump main body, or an outside air temperature, or a temperature of a pipe portion, and the hot water storage tank is connected to the temperature detecting means. A freeze prevention heater for heating the pipe portion, and control means for controlling energization to the freeze prevention heater based on a temperature detected by the temperature detection means, wherein the freeze prevention heater is provided at least below the hot water storage tank. Since it is configured to be attached to each connected pipe and operate independently for each pipe, even if some of the anti-freeze heaters do not function and some of the pipes freeze, Inexpensive and highly reliable heat pump that can open the water stopcock, air vent plug, emergency intake plug, etc. provided in the piping of, and drain the water in the hot water storage tank without freezing and damaging the hot water storage tank A hot water heater can be provided.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a heat pump water heater according to Embodiment 1 of the present invention.
FIG. 2 is a configuration diagram of a heat pump main body according to the first embodiment of the present invention.
FIG. 3 is a block diagram of a control circuit of the anti-freezing heater according to the first embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hot-water heater main body, 2 hot-water storage tank, 3 water supply piping, 5 hot-water supply piping, 8 heat pump main body, 9 cold-water piping, 10 hot-water piping, 13 control part, 16 water stopcock, 17 drainage pipe, 27a-27e, 28a-28c, 29a Freezing prevention heater, 30 Outside air temperature sensor, 31 Air vent plug, 32 Emergency intake plug.

Claims (1)

A water heater main body and a heat pump main body as a heating source are provided, and a hot water storage tank provided in the water heater main body and a hot water storage heat exchanger provided in the heat pump main body are annularly connected by a cold water pipe and a hot water pipe. Forming a circulation circuit, and operating a circulation pump provided in the cold water pipe of the circulation circuit to take out low-temperature water from the lower part of the hot water storage tank and send it to the hot water storage heat exchanger in the heat pump main body through the cold water pipe. A heat pump water heater configured to return hot water heated by the heat exchanger for hot water storage to a high temperature in the hot water storage tank through the hot water pipe;
Temperature detecting means for detecting the internal temperature of the water heater main body or the heat pump main body, or the outside air temperature, or the temperature of the pipe portion; a freeze prevention heater for heating a pipe portion connected to the hot water storage tank; and the temperature detecting means. Control means for controlling energization to the anti-freezing heater based on the detected temperature of the anti-freezing heater, wherein the anti-freezing heater is attached to at least each pipe connected to the lower part of the hot water storage tank, and is independent for each of the pipes. A heat pump water heater characterized in that the heat pump water heater is configured to operate.

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