JP5359228B2 - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water heater requiring no attachment of a water stop valve to a pipe connecting a heating means to a tank. <P>SOLUTION: In this water heater 1, a cross valve 38 is switched over to any one of a first condition in which water in the tank 31 is not led to flow into both a forward pipe 36 and a drain pipe 39, a second condition in which water in the tank 31 is led to flow into the forward pipe 36 and is not led to flow into the drain pipe 39, and a third condition in which water in the tank 31 is led to flow into the drain pipe 39 and is not led to flow into the forward pipe 36. As a result, two water stop valves required in the existing water heater can be eliminated, to reduce time and effort for construction work. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a water heater that stores water heated by a heating means in a tank.

A heat pump unit used as heating means for a water heater and a tank in which heated water is stored are communicated with each other by an outward pipe and a return pipe (see, for example, Patent Document 1). In such a water heater, at the time of installation, a water stop valve is provided between the heat pump unit and the forward pipe and between the heat pump unit and the return pipe. The water shutoff valve is opened and closed together with the air vent plug when removing water that has entered the tank and piping after installation of the water heater, but it is left open when the water heater is properly used. The
Japanese Patent Application Laid-Open No. 2007-113836

  The water stop valve is attached by an operator at the installation site of the water heater, and the work for installing the water stop valve and the air venting operation using the water stop valve are troublesome operations for the operator.

  The subject of this invention is providing the water heater which does not need to attach a water stop valve to the forward pipe and return pipe which connect a heating means and a tank.

  A water heater according to a first aspect of the present invention is a water heater that stores water heated by a heating means in a tank, and includes a forward pipe, a drain pipe, and a three-way valve. The forward pipe directs the tank water to the heating means by means of a pump. The drain pipe guides the tank water to the drain outlet. The three-way valve has a first state in which the tank water does not flow to both the forward pipe and the drain pipe, a second state in which the tank water flows to the forward pipe and does not flow to the drain pipe, and the tank water flows to the drain pipe. It is switched to one of the third states that do not flow to the tube.

  In a conventional water heater in which the outgoing pipe extends directly from the tank, a water stop valve is required on each of the outgoing pipe and the return pipe connected to the tank from the heating means. However, in the water heater according to the first aspect of the invention, the first state in which the water in the tank does not flow to both the forward pipe and the drain pipe by the three-way valve, the second state in which the water in the tank flows to the forward pipe and does not flow to the drain pipe, In addition, the water can be switched to one of the third states in which the water of the tank flows into the drain pipe and does not flow into the forward pipe. As a result, two water stop valves can be abolished, and the labor of construction work is reduced. Furthermore, since the three-way valve also serves as a drain valve, the number of parts is reduced as a whole.

  The water heater according to the second invention is the water heater according to the first invention, further comprising a return pipe and a return three-way valve. The return pipe guides the water returning from the heating means to the lower part of the tank through the pipe joint. The return three-way valve is provided in the middle of the return pipe. The pump is disposed at a position lower than the uppermost part of the pipe connected to the bottom of the tank through the return three-way valve from the pipe joint in the return pipe.

  In this water heater, when water is poured into the tank during construction of the water heater, the air that was present in the piping moves to a higher position than the pump, so that the water enters the pump securely and the air Is prevented.

  An air venting method for a water heater according to a third aspect of the present invention is an air venting method for the water heater according to the first or second aspect of the present invention, wherein the water heater further includes an air vent plug. The air vent plug releases air that has moved with the water from the tank. When the tank is filled with water from the air, an air venting operation is performed to release air-mixed water from the air vent plug. Prior to the air venting operation, the three-way valve is switched to the first state.

  In a conventional water heater where the outgoing pipe extends directly from the tank, a stop valve is attached on the outgoing pipe and the return pipe connected from the heating means to the tank, and the stop valve on the outgoing pipe side is installed before the air venting operation. Close work was required. However, in the method for ventilating the hot water supply apparatus according to the third aspect of the invention, the water in the tank is switched to the first state in which the water does not flow through both the forward pipe and the drain pipe by a single operation of the three-way valve. As a result, the air venting operation can be reliably performed even after the stoppage of the water stop valve.

  An air venting method for a water heater according to a fourth invention is an air venting method for the water heater according to the first invention, wherein the water heater includes a return pipe, a return three-way valve, a return branch pipe, a controller, and an air vent. And a stopper. The return pipe guides the water returning from the heating means to the lower part of the tank. The return three-way valve is provided in the middle of the return pipe. The return branch pipe guides water from the return three-way valve to the upper part of the tank. The control unit controls the return three-way valve. The air vent plug releases air that has moved with the water from the tank. When the tank changes from an empty state to a full state, and the controller is in a state where water is circulated to the return branch pipe via the return three-way valve, an air release operation for releasing air-mixed water from the air release plug is performed. Done. Prior to the air venting operation, the three-way valve is switched to the first state.

  In this air venting operation, the air returning from the heating means is returned to the upper part of the tank, so that the air is more easily removed.

  An air venting method for a hot water heater according to a fifth aspect of the present invention is an air venting method for the hot water heater according to the second aspect of the present invention, wherein the hot water heater further includes a return branch pipe, a controller, and an air vent plug. The return pipe guides the water returning from the heating means to the lower part of the tank. The return three-way valve is provided in the middle of the return pipe. The return branch pipe guides water from the return three-way valve to the upper part of the tank. The control unit controls the return three-way valve. The air vent plug releases air that has moved with the water from the tank. When the tank changes from an empty state to a full state, and the controller is in a state where water is circulated to the return branch pipe via the return three-way valve, an air release operation for releasing air-mixed water from the air release plug is performed. Done. Prior to the air venting operation, the three-way valve is switched to the first state.

  In this air venting operation, the air returning from the heating means is returned to the upper part of the tank, so that the air is more easily removed.

  An air venting method for a hot water heater according to a sixth aspect of the present invention is an air venting method for the hot water heater according to the first or second invention, wherein the hot water heater further includes an air vent plug. The air vent plug releases air that has moved with the water from the tank. The air vent plug includes a water side air vent plug and a hot water side air vent plug. The water side air vent plug is provided on the water inlet side of the heating means. The hot water side air vent plug is provided on the water outlet side of the heating means. When the tank is filled with water from the air, an air venting operation is performed to release air-mixed water from the air vent plug. The air vent operation includes a first air vent operation and a second air vent operation. The first air venting operation is an operation of releasing air-mixed water from both the water side air vent plug and the hot water side air vent plug. The second air venting operation is an operation of releasing air-mixed water only from the water-side air vent plug after the first air venting operation. Prior to the second air vent operation, the three-way valve is switched to the first state.

  In a conventional water heater where the outgoing pipe extends directly from the tank, a stop valve is attached on the outgoing pipe and the return pipe connected from the heating means to the tank, and the stop valve on the outgoing pipe side is installed before the air venting operation. Close work was required. However, in the air venting method for a water heater according to the sixth aspect of the invention, the water in the tank is switched to the first state in which the water does not flow to both the forward pipe and the drain pipe by a single operation of the three-way valve. As a result, the air venting operation can be reliably performed even after the stoppage of the water stop valve.

  An air vent method for a water heater according to a seventh aspect of the present invention is the air vent method for a water heater according to any one of the second to sixth aspects, wherein the three-way valve is switched to the second state after the air vent operation.

  In a conventional water heater where the outgoing pipe extends directly from the tank, a stop valve is attached on the outgoing pipe and the return pipe connected to the tank from the heating means, and the stop valve on the outgoing pipe side is closed at the start of operation. It needed work to open. However, in the method for ventilating the hot water supply apparatus according to the seventh aspect of the invention, the operation is switched to the second state in which the water in the tank flows to the forward pipe and does not flow to the drain pipe by a single operation of the three-way valve. As a result, the air venting operation can be reliably performed even after the stoppage of the water stop valve.

  In the water heater according to the first aspect of the present invention, the first state in which the water of the tank does not flow to both the forward pipe and the drain pipe, the second state in which the water of the tank flows to the forward pipe and does not flow to the drain pipe by the three-way valve, and the tank Is switched to one of the third states where the water is allowed to flow to the drain pipe and not to the forward pipe. As a result, two water stop valves can be abolished, and the labor of construction work is reduced. Furthermore, since the three-way valve also serves as a drain valve, the number of parts is reduced as a whole.

  In the water heater according to the second aspect of the invention, when water is poured into the tank during construction of the water heater, water is surely introduced into the pump, so that air pumping of the pump is prevented.

  In the air venting method for a water heater according to the third aspect of the invention, the water in the tank is switched to the first state in which the water does not flow to both the forward pipe and the drain pipe by a single operation of the three-way valve. As a result, the air venting operation can be reliably performed even after the stoppage of the water stop valve.

  In the method for ventilating the hot water supply apparatus according to the fourth or fifth aspect of the invention, returning the water returning from the heating means to the upper part of the tank makes it easier for air to escape.

  In the air venting method for a water heater according to the sixth aspect of the invention, the operation is switched to the first state in which the water in the tank does not flow through both the forward pipe and the drain pipe by a single operation of the three-way valve. As a result, the air venting operation can be reliably performed even after the stoppage of the water stop valve.

  In the air venting method for a water heater according to the seventh aspect of the present invention, the operation is switched to the second state in which the water in the tank flows into the forward pipe and does not flow into the drain pipe by a single operation of the three-way valve. As a result, the air venting operation can be reliably performed even after the stoppage of the water stop valve.

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

[First Embodiment]
<Configuration of water heater 1>
FIG. 1 is an external perspective view of a water heater according to the first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of the water heater. In FIG. 1, a water heater 1 includes a heat pump unit (heating means) 2 and a hot water storage device 3, and a vapor compression refrigeration circuit is housed in a casing 120 of the heat pump unit 2. A tank 31 is accommodated in the casing 130.

  The heat pump unit 2 and the hot water storage device 3 are connected to each other by an outward pipe 36 and a return pipe 37 so that water can flow. Water in the tank 31 enters the heat pump unit 2 through the forward pipe 36. The water heated by the heat pump unit 2 returns to the tank 31 through the return pipe 37.

  A water-side air vent plug 27 a is provided at a connection portion between the heat pump unit 2 and the forward pipe 36, and a hot water-side air vent plug 27 b is provided at a connection portion between the heat pump unit 2 and the return pipe 37. For convenience, the water side air vent plug 27a and the hot water side air vent plug 27b are collectively referred to as the air vent plug 27. The air vent plug 27 is used for venting air that has entered the tank 31 and the piping when the tank 31 is filled from an empty state.

  Below the hot water storage device 3, an operation lever 38 a and a drain port 40 of the three-way valve 38 are provided. As seen from the front of FIG. 1, the operator turns the operation lever 38 a to the right side, so that the water in the tank 31 is directed to the drain port 40. When the operator turns the operation lever 38 a to the left side, the water in the tank 31 is directed to the forward pipe 36. Then, when the operator directs the operation lever 38 a directly below, the water in the tank 31 is not directed to either the forward pipe 36 or the drain port 40.

  An operation lever 75 a of the relief valve 75 is provided on the upper part of the hot water storage device 3. When supplying water into the tank 31, the operator opens the relief valve 75 with the operation lever 75a facing upward. The inside of the tank 31 is full, and the water overflowing from the tank 31 flows to the drainage hose 140 through the relief valve 75.

  In FIG. 2, the heat pump unit 2 includes a muffler 21 a, a compressor 21, a refrigerant pipe 22 a in the water heat exchanger 22, an expansion valve 23 as a decompression unit, and an air heat exchanger 24 connected in a ring shape by a refrigerant pipe 25. The vapor compression refrigeration circuit 20 is provided.

  The refrigeration circuit 20 is provided with a liquid gas heat exchanger 26 for heat exchange between the high-pressure and high-temperature refrigerant coming out of the water heat exchanger 22 and the low-pressure and low-temperature refrigerant coming out of the air heat exchanger 24. Has been. Specifically, heat exchange is performed between the refrigerant passage connecting the water heat exchanger 22 and the expansion valve 23 and the refrigerant passage connecting the air heat exchanger 24 and the compressor 21.

  The hot water storage device 3 includes a water circulation circuit 30 in which a tank 31, a water pipe 22 b in the water heat exchanger 22, and a water circulation pump 32 are annularly connected by a water circulation pipe 34. The control unit 4 controls the operation of the heat pump unit 2 and the hot water storage device 3.

<Hot water storage device 3>
FIG. 3 is a circuit diagram of piping for connecting a hot water storage device of a water heater and a load according to an embodiment of the present invention. In addition, the load described here refers to hot water supply and a bath. The hot water supply pipe 71 communicates the head of the tank 31 with the hot water supply mixing valve 73. The hot water supply pipe 71 has a first hot water supply branch pipe 71a and a second hot water supply branch pipe 71b. The first hot water supply branch pipe 71a connects the hot water supply pipe 71 and the hot water beam mixing valve 74, and the second hot water supply branch pipe. 71 b communicates the hot water supply pipe 71 and the relief valve 75.

  The water supply pipe 72 connects the water supply source and the hot water supply mixing valve 73. The water supply pipe 72 has a first water supply branch pipe 72a and a second water supply branch pipe 72b. The first water supply branch pipe 72a communicates the water supply pipe 72 and the hot water mixing valve 74, and the second water supply branch. The pipe 72 b connects the water supply pipe 72 and the bottom of the tank 31. A pressure reducing check valve 76 is connected upstream of the first water supply branch pipe 72a and the second water supply branch pipe 72b. Further, a water temperature sensor 41 is provided at a position away from the tank 31 of the second water supply branch pipe 72 b, so that the water temperature sensor 41 is not affected by the temperature from the tank 31.

  The hot water circulation pipe 77 communicates the top of the tank 31 and the bottom of the tank 31, and a memorial heat exchanger 78 and a circulation pump 79 are connected midway.

  The second hot water supply pipe 81 connects the hot water supply mixing valve 73 and the hot water supply port 82, and a hot water supply water amount sensor 42a is disposed on the way. The third hot water supply pipe 83 communicates the hot water beam mixing valve 74 and the bath water circulation pipe 91, and a composite water valve 84 is disposed in the middle. The composite water valve 84 includes a hot water solenoid valve 84a, a drain valve 84b, and a hot water volume sensor 42b.

  The bath water circulation pipe 91 exits from the bathtub 92 and returns to the bathtub 92, and a bath water circulation pump 93 is connected on the way. It should be noted that heat is exchanged between the bath water circulation pipe 91 and the hot water circulation pipe 77 in the memory heat exchanger 78.

  The auxiliary forward pipe 35 a and the forward pipe 36 communicate the bottom of the tank 31 with the heat pump unit 2. The auxiliary forward pipe 35a and the forward pipe 36 are connected via a three-way valve 38. That is, the auxiliary forward pipe 35 a is connected to the inlet A of the three-way valve 38, and the forward pipe 36 is connected to the outlet C of the three-way valve 38.

  The auxiliary drain pipe 35 b and the drain pipe 39 communicate the bottom of the tank 31 and the drain port 40. The auxiliary drain pipe 35b and the drain pipe 39 are connected via a three-way valve 38. That is, the auxiliary drain pipe 35 b is connected to the inlet A of the three-way valve 38, and the drain pipe 39 is connected to the outlet B of the three-way valve 38. Since the auxiliary forward pipe 35a and the auxiliary drain pipe 35b are connected to the inlet A of the three-way valve 38, they may be shared by one pipe. In this embodiment, it is shared by one common pipe 35.

  The return pipe 37 communicates the heat pump unit 2 and the bottom of the tank 31. A return three-way valve 52 is provided in the middle of the return pipe 37. The return three-way valve 52 is controlled by the control unit 4. The return branch pipe 37 a communicates the return three-way valve 52 with the head of the tank 31. The control unit 4 causes the water in the return pipe 37 to flow to the head of the tank 31 via the return three-way valve 52.

  On the side wall of the tank 31, temperature sensors 44a to 44e are provided as a remaining hot water amount detecting means at a constant interval from the head to the bottom. The temperature of the hot water and the amount of remaining hot water are calculated by detecting the hot water temperature at each height position of the tank 31 with the temperature sensors 44a to 44e. In addition, the tank 31 is covered with a heat insulating material on the entire periphery of the side portion, the head portion, and the bottom portion.

<Operation of three-way valve 38 and direction of water flow>
Here, how the water flows by the operation of the operation lever 38a of the three-way valve 38 will be described with reference to FIGS. When the operation lever 38a (see FIG. 1) is directed directly below, the inlet A of the three-way valve 38 (see FIG. 3) is not connected to either the outlet B or the outlet C, and the water in the tank 31 passes through the common pipe 35. It will be in a stopped state. This state is referred to as a first state.

  By directing the operation lever 38a (see FIG. 1) to the left, the inlet A and the outlet C of the three-way valve 38 (see FIG. 3) are connected, and the water in the tank 31 flows from the common pipe 35 to the forward pipe 36. A water circulation pump 32 is provided in the middle of the forward pipe 36, and water in the forward pipe 36 is directed to the heat pump unit 2 by the water circulation pump 32. This state is called a second state.

  By directing the operation lever 38a (see FIG. 1) to the right side, the inlet A and the outlet B of the three-way valve 38 (see FIG. 3) are connected, and the water in the tank 31 flows from the common pipe 35 to the drain pipe 39. The water in the drain pipe 39 flows out through the drain port 40. This state is referred to as a third state.

<Air venting>
When the water heater 1 is installed, the air must be vented. FIG. 4 is a flow of the air venting operation of the water heater according to one embodiment of the present invention, and the air venting operation will be described below with reference to FIG. The worker performs the air venting operation according to the 12 work procedures from S1 to S12. The workers referred to here include installation workers and general users of the water heater 1.

  First, as a work procedure S <b> 1, the operator sets the operation lever 38 a of the three-way valve 38 to the left so that the water in the tank 31 flows into the forward pipe 36.

  Next, as operation procedure S2, the operation lever 75a of the relief valve 75 is turned upward, and the relief valve 75 is opened. As work procedure S3, water is supplied from the water supply pipe 72 to the bottom of the tank 31. As work procedure S4, it is determined whether or not the tank 31 is full.

  Since the water rises from the bottom of the tank 31 toward the head, the water that overflows when the tank 31 is full flows out from the relief valve 75 through the drain hose 140 to the outside. Therefore, the operator confirms that water is continuously discharged from the outlet of the drainage hose 140, and determines that the tank 31 is full. After confirming that water is continuously discharged from the outlet of the drainage hose 140, the worker turns the operation valve 75 of the relief valve 75 downward and closes the relief valve 75 as a work procedure S5.

  Next, as work procedure S6, the water side air vent plug 27a and the hot water side air vent plug 27b are opened to discharge water. As work procedure S7, it is confirmed that water is continuously discharged from the water side air vent plug 27a and the hot water side air vent plug 27b. When air is mixed in the tank 31 and the pipe, water mixed with air comes out from the water side air vent plug 27a and the hot water side air vent plug 27b. The work procedure S7 is called a first air vent operation.

  After confirming that water is continuously discharged from the water side air vent plug 27a and the hot water side air vent plug 27b, the worker closed the hot water side air vent plug 27b and opened only the water side air vent plug 27a as operation procedure S8. Put it in a state. As work procedure S9, the operation lever 38a of the three-way valve 38 is directed directly below so that the water in the tank 31 does not flow into either the forward pipe 36 or the drain pipe 39.

  Next, as work procedure S10, it is confirmed that water is continuously discharged from the water-side air vent plug 27a. When air is still mixed in the tank 31 and the pipe, water mixed with air comes out from the water-side air vent plug 27a. The work procedure S10 is called a second air vent operation.

  After confirming that water is continuously discharged from the water-side air vent plug 27a, the worker closes the water-side air vent plug 27a as a work procedure S11. Finally, as work procedure S12, the operation lever 38a of the three-way valve 38 is turned to the left so that the water in the tank 31 flows into the forward pipe 36.

<Drainage work>
When the water heater 1 is not used for a long period of time, it is preferable to drain all the water in the tank 31. FIG. 5 is a flow of the drainage operation of the water heater according to one embodiment of the present invention. Hereinafter, the drainage operation will be described with reference to FIG. The worker performs the drainage work according to the four work procedures from S21 to S24. The workers referred to here include installation workers and general users of the water heater 1.

  First, as an operation procedure S21, the operator turns the operation lever 75a of the relief valve 75 upward and opens the relief valve 75 to prevent the inside of the tank 31 from becoming negative pressure. Next, as operation procedure S22, the operation lever 38a of the three-way valve 38 is turned to the right so that the water in the tank 31 flows into the drain pipe 39, and the water in the tank 31 is discharged from the drain port 40.

  As work procedure S23, it is confirmed that water is not discharged from the drain port 40 and drainage is completed. After confirming that the drainage is completed, the operator connects the inlet A and the outlet C of the three-way valve 38 with the operation lever 38a of the three-way valve 38 facing left as a work procedure S24.

<Features>
(1)
In the water heater 1, a first state in which the water in the tank 31 does not flow to both the forward pipe 36 and the drain pipe 39 by the three-way valve 38, and the second state in which the water in the tank 31 flows to the forward pipe 36 and does not flow to the drain pipe 39. The state is switched to one of the third state where the water in the tank 31 flows into the drain pipe 39 and does not flow into the forward pipe 36. As a result, it is possible to eliminate the two water stop valves that are necessary for the conventional water heater, and the labor of construction work is reduced. Furthermore, since the three-way valve also serves as a drain valve, the number of parts is reduced as a whole.

(2)
In the water heater 1, when the tank is filled with water from the air, the operator performs the first air vent operation and the second air vent operation. The first air venting operation is an operation of releasing air-mixed water from both the water side air vent plug 27a and the hot water side air vent plug 27b. The second air venting operation is an operation of releasing water mixed with air only from the water-side air vent plug 27a after the first air venting operation. Before the second air venting operation, the operator operates the three-way valve 38 to switch to the first state, and after the second air venting operation, operates the three-way valve 38 to switch to the second state. As a result, the air venting operation can be reliably performed even after the stoppage of the water stop valve.

<Modification of air venting>
In the said embodiment, although 1st air venting operation and 2nd air venting operation are performed as air venting operation, an air venting operation can be carried out once and labor can be reduced. FIG. 6 is a flow of a modified example of the air venting operation of the water heater according to the present embodiment. Hereinafter, the air venting operation will be described with reference to FIG. 6. The worker performs the air venting operation according to the nine operation procedures from S101 to S111.

  First, as a work procedure S101, the worker turns the operation lever 38a of the three-way valve 38 to the left so that the water in the tank 31 flows into the forward pipe 36.

  Next, as the operation procedure S102, the operation lever 75a of the relief valve 75 is turned upward to open the relief valve 75. As work procedure S103, water is supplied from the water supply pipe 72 to the bottom of the tank 31. As work procedure S104, it is determined whether or not the tank 31 is full.

  Since the water rises from the bottom of the tank 31 toward the head, the water that overflows when the tank 31 is full flows out from the relief valve 75 through the drain hose 140 to the outside. Therefore, the operator confirms that water is continuously discharged from the outlet of the drainage hose 140, and determines that the tank 31 is full.

  After confirming that water is continuously discharged from the outlet of the drainage hose 140, the operator turns the operation valve 75 of the relief valve 75 downward and closes the relief valve 75 as an operation procedure S105.

  As a work procedure S106, the operator operates the control unit 4 to forcibly operate the return three-way valve 52 so that the water in the return pipe 37 flows into the return branch pipe 37a. Next, as work procedure S107, the water-side air vent plug 27a is opened to discharge water. Then, as the work procedure S108, the operation lever 38a of the three-way valve 38 is directed directly below so that the water in the tank 31 does not flow into either the forward pipe 36 or the drain pipe 39.

  The worker confirms that water is continuously discharged from the water-side air vent plug 27a as the work procedure S109. When air is still mixed in the tank 31 and the pipe, water mixed with air comes out from the water-side air vent plug 27a. The work procedure S109 is called an air bleeding operation.

  After confirming that water is continuously discharged from the water-side air vent plug 27a, the worker closes the water-side air vent plug 27a as a work procedure S110. Finally, as work procedure S111, the operation lever 38a of the three-way valve 38 is turned to the left so that the water in the tank 31 flows into the forward pipe 36.

<Characteristics of modified air venting>
In the water heater 1, when the tank 31 is changed from an empty water state to a full water state and the control unit 4 is in a state where water is circulated to the return branch pipe 37 a via the return three-way valve 52, An air venting operation for releasing water-mixed water from the side air vent plug 27a is performed. Further, the operator operates the three-way valve 38 to switch to the first state before the air bleeding operation. As a result, it becomes easier for air to escape.

[Second Embodiment]
As described in the description of the air venting operation, when the water heater 1 is installed, water is supplied from the water supply pipe 72 to the bottom of the tank 31 and becomes full. In the water heater 1 according to the second embodiment, the water circulation pump 32 sets the return three-way valve 52 from the return pipe joint 28b so that air does not stay in the water circulation pump 32 when water is supplied to the tank 31. Then, it is arranged at a position lower than the uppermost part of the pipe connected to the bottom of the tank 31. Hereinafter, the difference between the case where the water circulation pump 32 is located higher than the uppermost part of the pipe and the case where the water circulation pump 32 is located lower than the uppermost part of the pipe will be described with reference to the drawings.

  Fig.7 (a) is a schematic block diagram of the water heater which has a pump in the position higher than the uppermost part of piping connected to the bottom part of a tank through a return three-way valve from a return pipe joint. (B) is a schematic block diagram of a water heater having a pump at a position lower than the uppermost part of the pipe connected to the bottom of the tank through the return three-way valve from the return pipe joint. 7 (a) and 7 (b), the black painted portion of the pipe in the figure means the presence of water, and the white painted portion of the pipe means the presence of air. In addition, since the component of 2nd Embodiment is the same as that of 1st Embodiment, the code | symbol similar to 1st Embodiment is used for a component, and description is abbreviate | omitted.

  In FIG. 1, FIG. 3, FIG. 7A and FIG. 7B, the pipe inside the hot water storage device 3 and the pipe outside the hot water storage device 3 among the forward pipes 36 are connected by the forward pipe joint 28a. Of the return pipe 37, the pipe inside the hot water storage device 3 and the pipe outside the hot water storage device 3 are connected by a return pipe joint 28b. When the water heater 1 is installed, the return three-way valve 52 is open to the side where the water is returned to the bottom of the tank 31.

  As shown in FIG. 7A, if the water circulation pump 32 is located at a position higher than the uppermost part of the pipe connected to the bottom of the tank 31 through the return three-way valve 52 from the return pipe joint 28b, the water supply pipe 72 is provided. The water supplied to the bottom of the tank 31 from the bottom flows into the forward pipe 36 and the return pipe 37 from the bottom of the tank 31 toward the heat pump unit 2. The air existing in the forward pipe 36 and the return pipe 37 before water supply is pushed by the water flowing from the forward pipe 36 and the return pipe 37 and gathers in the water circulation pump 32 at the uppermost position of the circulation path. As a result, the water circulation pump 32 is sandwiched between air. Even if the water level of the tank 31 rises and becomes full, air cannot move because both ends of the water circulation pump 32 have the same water pressure. When the water circulation pump 32 is operated in this state, the water circulation pump 32 is engaged with air and cannot normally feed water, and water cannot circulate in the pipe.

  However, in the water heater 1 according to the second embodiment, as shown in FIG. 7B, the water circulation pump 32 is connected to the bottom of the tank 31 via the return three-way valve 52 from the return pipe joint 28b. When the position is lower than the upper part, the water supplied from the water supply pipe 72 to the bottom of the tank 31 flows into the forward pipe 36 and the return pipe 37 from the bottom of the tank 31 and travels toward the heat pump unit 2. The air existing in the forward pipe 36 and the return pipe 37 before the water supply is pushed by the water flowing from the forward pipe 36 and the return pipe 37 and gathers in the return three-way valve 52 at the uppermost position of the circulation path. As a result, the return three-way valve 52 is sandwiched between air. Even if the water level of the tank 31 rises and becomes full, air cannot move because both ends of the return three-way valve 52 have the same water pressure. When the water circulation pump 32 operates in this state, the water circulation pump 32 can feed water normally because it does not bite air. As a result, water sufficiently circulates in the piping, so that the air is pushed by the water, moves to the head of the tank 31 through the bottom of the tank 31, and finally escapes into the atmosphere.

  Even if air remains in the pipe after the air venting operation, the air is finally released into the atmosphere by preventing the air from being collected in the water circulation pump 32 as in the second embodiment. .

<Features of Second Embodiment>
In the water heater 1, the water circulation pump 32 is disposed at a position lower than the uppermost portion of the pipe connected to the bottom of the tank 31 through the return three-way valve 52 from the return pipe joint 28 b. As a result, when water is supplied into the tank 31 at the time of construction, water reliably enters the water circulation pump 32, thereby preventing air from being pumped.

  As described above, according to the present invention, it is not necessary to provide a water stop valve on the pipe that communicates between the heating unit that heats water and the tank that stores the water heated by the heating unit. This is useful for a water heater of the type that circulates water between the heating means.

1 is an external perspective view of a water heater according to a first embodiment of the present invention. The schematic block diagram of a water heater. The circuit diagram of the piping which connects the hot water storage apparatus and load of a water heater. The flow of air venting work for a water heater. Flow of water heater drainage work. The flow of the modification of the air venting work of a water heater. (A) The schematic block diagram of the water heater which has a pump in the position higher than the uppermost part of piping connected to the bottom part of a tank through a return three-way valve from a return pipe joint. (B) It is a schematic block diagram of the water heater which has a pump in the position lower than the uppermost part of piping connected to the bottom part of a tank through a return three-way valve from a return pipe joint.

Explanation of symbols

1 Water heater 2 Heat pump unit (heating means)
4 Control unit 27 Air vent plug 27a Water side air vent plug 27b Hot water side air vent plug 28b Return pipe joint 31 Tank 32 Water circulation pump 35a Auxiliary forward pipe 35b Auxiliary drain pipe 36 Outward pipe 37 Return pipe 37a Return branch pipe 38 Three-way valve 39 Drain pipe 40 Drain port 52 Return three-way valve

Claims (7)

A water heater for storing water heated by the heating means (2) in a tank (31),
Forward pipes (35a, 36) for directing water from the tank (31) to the heating means (2) by a pump (32);
Drain pipes (35b, 39) for guiding water from the tank (31) to the drain port (40);
The first state in which the water of the tank (31) does not flow to both the forward pipe (36) and the drain pipe (39), the water of the tank (31) flows to the forward pipe (36) and the drain pipe ( 39), and a three-way valve that can be switched to either the second state that does not flow to the drainage pipe (39) and the third state that does not flow the water from the tank (31) to the drain pipe (39). 38)
With
Water heater (1). A return pipe (37) for guiding water returning from the heating means (2) to the lower part of the tank (31) via a pipe joint (28b);
A return three-way valve (52) provided in the middle of the return pipe (37);
Further comprising
The pump (32) is lower than the uppermost part of the pipe connected to the bottom of the tank (31) from the pipe joint (28b) through the return three-way valve (52) in the return pipe (37). Located in the
The water heater (1) according to claim 1. The water heater (1) according to claim 1 or 2, further comprising an air vent plug (27) for releasing air that has moved with water from the tank (31).
The air venting method of
When the tank (31) is filled from empty water, an air venting operation is performed to release air-mixed water from the air vent plug (27),
Prior to the air venting operation, the three-way valve (38) is switched to the first state,
How to vent the water heater (1). A return pipe (37) for guiding water returning from the heating means (2) to the lower part of the tank (31);
A return three-way valve (52) provided in the middle of the return pipe (37);
A return branch pipe (37a) for guiding water from the return three-way valve (52) to the upper part of the tank (31);
A control unit (4) for controlling the return three-way valve (52);
An air vent plug (27) for releasing air that has moved with the water from the tank (31);
The water heater (1) according to claim 1, further comprising:
The air venting method of
When the tank (31) is filled with water from the water and the control unit (4) is in a state where water is circulated to the return branch pipe (37a) via the return three-way valve (52), An air venting operation for releasing air-mixed water from the air vent plug (27) is performed,
Prior to the air venting operation, the three-way valve (38) is switched to the first state,
How to vent the water heater (1). A return branch pipe (37a) for guiding water from the return three-way valve (52) to the upper part of the tank (31);
A control unit (4) for controlling the return three-way valve (52);
An air vent plug (27) for releasing air that has moved with the water from the tank (31);
The water heater (1) according to claim 2, further comprising:
The air venting method of
When the tank (31) is filled with water from the water and the control unit (4) is in a state where water is circulated to the return branch pipe (37a) via the return three-way valve (52), An air venting operation for releasing air-mixed water from the air vent plug (27) is performed,
Prior to the air venting operation, the three-way valve (38) is switched to the first state,
How to vent the water heater (1). The water heater (1) according to claim 1 or 2, further comprising an air vent plug (27) for releasing air that has moved with water from the tank (31).
The air venting method of
The air vent plug (27)
A water-side air vent plug (27a) provided on the water inlet side of the heating means (2);
A hot water side air vent plug (27b) provided on the water outlet side of the heating means (2);
Including
When the tank (31) is filled from empty water, an air venting operation is performed to release air-mixed water from the air vent plug (27),
The air venting operation is
A first air vent operation for releasing air-mixed water from both the water side air vent plug (27a) and the hot water side air vent plug (27b);
After the first air venting operation, a second air venting operation that releases air-mixed water only from the water side air vent plug (27a);
Including
Prior to the second air venting operation, the three-way valve (38) is switched to the first state,
How to vent the water heater (1). After the air venting operation, the three-way valve (38) is switched to the second state,
The method for ventilating the water heater (1) according to any one of claims 2 to 6.

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