JP2010156495A - Water heater and method of air venting from water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water heater dispensing with a water stop valve disposed in a pipe communicating a heating means with a tank. <P>SOLUTION: This water heater 1 is switched to any of a first state for blocking off the circulation of water among the tank, a return pipe and a drain pipe, a second state for circulating the water between the tank and the return pipe, and blocking off the circulation of water between the tank and the drain pipe, and a third state for circulating the water between the tank and the drain pipe and blocking off the circulation of water between the tank and the return pipe by a three-way valve 38. As a result, two water stop valves necessary for a conventional water heater can be eliminated, and the labor hour for a construction work can be reduced. <P>COPYRIGHT: (C)2010,JPO&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 a heating means for a water heater and a tank in which heated water is stored are connected to each other by a communication pipe called an outgoing pipe and a return pipe. The forward pipe is provided with a pump, and further, a water stop valve is provided between the heating means and the pump (see, for example, Patent Document 1). The water stop valve is opened and closed together with the air vent plug during the operation of venting the air that has entered the tank and the piping, but is left open when the water heater is properly used.
JP 2004-20075 A

  Since the water shut-off valve as described above is attached at the time of installing the water heater, it takes time and labor, resulting in an increase in cost.

  The subject of this invention is providing the water heater which eliminated the effort which attaches a water stop valve to the connection piping which connects 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 return pipe, a drain pipe, and a first three-way valve. The return pipe guides the water returning from the heating means to the lower part of the tank via the pipe joint. The drain pipe guides the tank water to the drain outlet. The first three-way valve is a first state in which the flow of water between the tank and the return pipe and the drain pipe is blocked, the water is passed between the tank and the return pipe, and the water between the tank and the drain pipe It is switched to either the second state where the flow is blocked or the third state where the water is circulated between the tank and the drain pipe and the water is blocked between the tank and the return pipe.

  Conventionally, when a water heater is installed, a water stop valve is attached to the return pipe. However, in the water heater according to the first aspect of the invention, the first three-way valve causes the water to flow between the tank and the return pipe in the first state where the flow of water between the tank and the return pipe and the drain pipe is blocked. And a second state in which the flow of water between the tank and the drain pipe is blocked, and a third state in which the water is circulated between the tank and the drain pipe and the flow of water between the tank and the return pipe is blocked. Therefore, the conventional water stop valve can be abolished, and the labor required to install the water stop valve is not required.

  A water heater according to a second aspect of the present invention is the water heater according to the first aspect of the present invention, and further includes an outward pipe and a second three-way valve. The forward pipe directs the tank water to the heating means by means of a pump. The second three-way valve is arranged on the return pipe, and switches so that water from the pipe joint toward the tank flows to the branch pipe leading to the upper part of the tank. The pump is disposed at a position lower than the uppermost part of the pipe connected to the bottom of the tank from the pipe joint through the second three-way valve 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 pipe moves to a higher position than the pump, so the pump is surely filled with water, Air biting 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 first three-way valve is switched to the first state.

  Conventionally, a stop valve is attached to the return pipe, and it is necessary to close the stop valve before the air venting operation. However, in the hot water venting method according to the third aspect of the invention, the operation of the first three-way valve is switched to the first state in which the flow of water between the tank and the return pipe and the drain pipe is blocked by one operation. Even if the water stop valve is abolished, the air venting operation is performed reliably.

  An air venting method for a water heater according to a fourth aspect of the present invention is an air venting method for the hot water heater according to the first aspect of the present invention, wherein the water heater further includes a second three-way valve, a controller, and an air vent plug. The second three-way valve is arranged on the return pipe, and switches the water from the pipe joint toward the tank to flow to the branch pipe leading to the upper part of the tank. The control unit controls the second three-way valve. 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 and the controller is in a state where water is circulated to the branch pipe via the second three-way valve, an air vent operation is performed to release air-mixed water from the air vent plug. Prior to the air venting operation, the first three-way valve is switched to the first state.

  Conventionally, a stop valve is attached to the return pipe, and it is necessary to close the stop valve before the air venting operation. However, in the method for ventilating the hot water heater according to the fourth aspect of the invention, the operation is switched to the first state in which the flow of water between the tank, the return pipe and the drain pipe is blocked by one operation of the first three-way valve. Even if the water stop valve is abolished, the air venting operation is performed reliably. Moreover, since the water returned from the heating means is returned to the upper part of the tank during the air venting operation, the air is easily removed.

  An air vent method for a hot water heater according to a fifth aspect of the present invention is an air vent method for the hot water heater according to the second aspect of the present invention, wherein the hot water heater further includes a control unit and an air vent plug. The control unit controls the second three-way valve. 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 and the controller is in a state where water is circulated to the branch pipe via the second three-way valve, an air vent operation is performed to release air-mixed water from the air vent plug. Prior to the air venting operation, the first three-way valve is switched to the first state.

  Conventionally, a stop valve is attached to the return pipe, and it is necessary to close the stop valve before the air venting operation. However, in the hot water venting method according to the fifth aspect of the invention, the operation is switched to the first state in which the flow of water between the tank, the return pipe and the drain pipe is blocked by one operation of the first three-way valve. Even if the water stop valve is abolished, the air venting operation is performed reliably. Moreover, since the water returned from the heating means is returned to the upper part of the tank during the air venting operation, the air is 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 water mixed with air only from the hot water side air vent plug after the first air venting operation. Prior to the second air vent operation, the first three-way valve is switched to the first state.

  Conventionally, a stop valve is attached to the return pipe, and it is necessary to close the stop valve before the air venting operation. However, in the hot water venting method according to the sixth aspect of the invention, the operation is switched to the first state in which the flow of water between the tank, the return pipe and the drain pipe is blocked by one operation of the first three-way valve. Even if the water stop valve is abolished, the air venting operation is performed reliably.

  An air venting method for a water heater according to a seventh aspect of the present invention is the air venting method for a hot water heater according to any one of the third to sixth aspects, wherein the first three-way valve switches to the second state after the air venting operation. It is done.

  Conventionally, a water stop valve is attached to the return pipe, and it is necessary to close the water stop valve before the air venting operation and open the water stop valve after the air vent operation. However, in the method for ventilating the water heater according to the seventh aspect of the invention, the water is circulated between the tank and the return pipe and the water is circulated between the tank and the drain pipe by one operation of the first three-way valve. Since it switches to the 2nd state which interrupts | blocks, even if it is the state where the water stop valve was abolished, the operation | work after air venting operation is performed without trouble.

  In the water heater according to the first aspect of the present invention, the conventional water stop valve can be abolished, and the labor required for mounting the water stop valve is not required.

  In the water heater according to the second invention, when water is poured into the tank at the time of construction of the water heater, the air present in the pipe moves to a position higher than the pump, so the pump is surely filled with water, Air biting during pump operation is prevented.

  In the method for ventilating the hot water supply apparatus according to the third aspect of the invention, the water is switched to the first state in which the flow of water between the tank, the return pipe and the drain pipe is blocked by one operation of the first three-way valve. Even if the valve is abolished, the air venting operation is performed reliably.

  In the method for ventilating the water heater according to the fourth or fifth aspect of the invention, the operation is switched to the first state in which the water flow between the tank, the return pipe and the drain pipe is blocked by one operation of the first three-way valve. Therefore, even if the water stop valve is abolished, the air venting operation is reliably performed. Moreover, since the water returned from the heating means is returned to the upper part of the tank during the air venting operation, the air is easily removed.

  In the air venting method for a water heater according to the sixth aspect of the present invention, the operation is switched to the first state in which the flow of water between the tank, the return pipe and the drain pipe is blocked by a single operation of the first three-way valve. Even if the valve is abolished, the air venting operation is performed reliably.

  In the air venting method for a water heater according to the seventh aspect of the present invention, the water is circulated between the tank and the return pipe and the water is circulated between the tank and the drain pipe by a single operation of the first three-way valve. Since it is switched to the second state, even after the water stop valve is abolished, the work after the air venting operation is performed without any trouble.

  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. 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 return pipe 37. Then, when the operator directs the operation lever 38 a directly below, the water in the tank 31 is not directed to either the return pipe 37 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.

  FIG. 2 is a schematic configuration diagram of the water heater according to the first embodiment. 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 refrigerant circuit 20 is provided.

  The refrigerant circuit 20 is provided with a liquid gas heat exchanger 26 for exchanging heat 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 that connects the hot water storage device of the water heater according to the first embodiment and a load. 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 forward pipe 36 communicates the bottom of the tank 31 and the heat pump unit 2. The auxiliary return pipe 35 a and the return pipe 37 communicate the heat pump unit 2 and the bottom of the tank 31. The auxiliary return pipe 35a and the return pipe 37 are connected via a three-way valve 38. That is, the auxiliary return pipe 35 a is connected to the inlet A of the three-way valve 38, and the return pipe 37 is connected to the outlet C of the three-way valve 38.

  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.

  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 return 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.

  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 turning 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 bottom of the tank 31, the common pipe 35, and the return pipe 37 are connected. A return three-way valve 52 is provided in the middle of the return pipe 37. A state in which the bottom of the tank 31, the common pipe 35, the return pipe 37, and the heat pump unit 2 are connected so that water can flow is referred to as a second state.

  By turning the operation lever 38a (see FIG. 1) to the right, 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 the first embodiment of the present invention. Hereinafter, the air venting operation will be described 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 an operation procedure S1, the operator turns the operation lever 38a of the three-way valve 38 to the left so that water can flow between the tank 31 and the return pipe 37.

  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 of 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 water side air vent plug 27a and opened only the hot water side air vent plug 27b as operation procedure S8. Put it in a state. As work procedure S <b> 9, the operation lever 38 a of the three-way valve 38 is directed directly below so that the water in the tank 31 does not flow into either the return pipe 37 or the drain pipe 39.

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

  After confirming that water is continuously discharged from the hot water side air vent plug 27b, the worker closes the hot water side air vent plug 27b 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 water can flow between the tank 31 and the return pipe 37.

<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 flow of water between the tank 31 and the return pipe 37 and the drain pipe 39 is blocked by the three-way valve 38, the water is passed between the tank 31 and the return pipe 37, and the tank 2nd state which interrupts | blocks the flow of the water between 31 and the drain pipe 39, and distribute | circulates the water between the tank 31 and the drain pipe 39, and interrupts | blocks the water flow between the tank 31 and the return pipe 37 Is switched to one of the third states. As a result, the water stop valve required for the conventional water heater can be abolished, and the labor required for installing the water stop valve is not required.

(2)
In the water heater 1, when the tank 31 is filled from empty water, the operator performs 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 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 hot water side air vent plug 27b after the first air venting operation. The operator operates the three-way valve 38 to switch to the first state before the second air venting operation, and operates the three-way valve 38 to switch to the second state after the second air venting operation. As a result, the air venting operation is reliably performed even when the water stop valve is abolished.

<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 an operation procedure S101, the operator turns the operation lever 38a of the three-way valve 38 to the left so that water can flow between the tank 31 and the return pipe 37.

  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 switch the return three-way valve 52 to the return branch pipe 37a side. Next, as work procedure S107, the hot water side air vent plug 27b 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 return pipe 37 or the drain pipe 39.

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

  After confirming that water is continuously discharged from the hot water side air vent plug 27b, the worker closes the hot water side air vent plug 27b as a work procedure S110. Finally, as a work procedure S111, the operation lever 38a of the three-way valve 38 is turned to the left so that water can flow between the tank 31 and the return pipe 37.

<Characteristics of modified air venting>
In the water heater 1, when the tank 31 changes 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 is performed to release air-mixed water from the side air vent plug 27b. 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 passes through 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. 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 useful for a water heater of a type that circulates water between a tank and a 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) The 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 part 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 return pipe (return pipe)
35b Auxiliary drain pipe (drain pipe)
36 Outward pipe 37 Return pipe 37a Return branch pipe 38 Three-way valve (first three-way valve)
39 Drain pipe 40 Drain port 52 Return three-way valve (second three-way valve)

Claims (7)

A water heater for storing water heated by the heating means (2) in a tank (31),
A return pipe (35a, 37) for guiding water returning from the heating means (2) to the lower part of the tank (31) via a pipe joint (28b);
Drain pipes (35b, 39) for guiding water from the tank (31) to the drain port (40);
A first state in which the flow of water between the tank (31) and the return pipe (37) and the drain pipe (39) is blocked; water between the tank (31) and the return pipe (37); And the second state in which the water flow between the tank (31) and the drain pipe (39) is blocked, and the water is passed between the tank (31) and the drain pipe (39). And a first three-way valve (38) that is switched to any one of the third states that block the flow of water between the tank (31) and the return pipe (37),
With
Water heater (1). A forward pipe (36) for directing water in the tank (31) to the heating means (2) by a pump (32);
A second three-way valve which is arranged on the return pipe (37) and switches the water from the pipe joint (28b) toward the tank (31) to flow to the branch pipe (37a) leading to the upper part of the tank (31). (52)
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 second three-way valve (52) in the return pipe (37). Placed in position,
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),
Before the air venting operation, the first three-way valve (38) is switched to the first state,
How to vent the water heater (1). A second three-way valve which is arranged on the return pipe (37) and switches the water from the pipe joint (28b) toward the tank (31) to flow to the branch pipe (37a) leading to the upper part of the tank (31). (52)
A control unit (4) for controlling the second 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 full of air and the control unit (4) is in a state where water is circulated to the branch pipe (37a) via the second three-way valve (52), An air venting operation for releasing air-mixed water from the air vent plug (27) is performed,
Before the air venting operation, the first three-way valve (38) is switched to the first state,
How to vent the water heater (1). A control unit (4) for controlling the second 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 full of air and the control unit (4) is in a state where water is circulated to the branch pipe (37a) via the second three-way valve (52), An air venting operation for releasing air-mixed water from the air vent plug (27) is performed,
Before the air venting operation, the first 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 hot water side air vent plug (27b);
Including
Before the second air venting operation, the first three-way valve (38) is switched to the first state,
How to vent the water heater (1). After the air venting operation, the first three-way valve (38) is switched to the second state,
The method for ventilating the water heater (1) according to any one of claims 3 to 6.

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