JPH0536245U - Electric water heater - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an electric water heater capable of supplying hot water even when cleaning a hot water storage tank. [Structure] A heater composed of a heating tank and an electric heater arranged inside the tank, an atmosphere open hot water storage tank for storing hot water from the heater, and hot water in the hot water storage tank to a hot water supply location. It is equipped with a hot water supply pump. A three-way valve is connected between the suction port of the hot water supply pump and the hot water storage tank, and the other inlet of this valve is connected to the heating tank by piping. With this configuration, the hot water in the heating tank can be supplied by switching the three-way valve, and as a result, the intended purpose can be achieved.

Description

[Detailed description of the device]

[0001]

TECHNICAL FIELD The present invention relates to an electric water heater used in a general house or the like.

[0002]

2. Description of the Related Art As an electric water heater, for example, hot water heated to a boiling temperature by a heater is supplied to an open-air hot water storage tank, and a predetermined volume of hot water is stored in the tank. There is something. In the electric water heater having such a structure, the hot water supply to the hot water storage tank, that is, the boiling operation is usually performed during the midnight electricity charge period (11 pm to 7 am).

[0003]

[Problems to be Solved by the Invention] In the electric water heater having the above structure, since the hot water storage tank is open to the atmosphere, the water in the tank is drained and washed about 2 to 4 times a year. There is a need to do. This cleaning work is started after supplying hot water to a place where the amount of hot water is used, for example, after filling the bathtub in the evening, but after the cleaning work is completed, there is no hot water in the hot water storage tank. Therefore, it is necessary to boil the water again by using the power at midnight, and therefore, the hot water cannot be used at all from the start of the cleaning work to the next morning (7:00 am).

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electric water heater capable of supplying hot water even when cleaning a hot water storage tank.

[0005]

Means for Solving the Problems A structure for achieving the above-mentioned object will be described with reference to FIG. 1 corresponding to an embodiment. The present invention has a heating tank 21 and an inside thereof. A heater 2 constituted by an electric heater 22, an open-air hot water storage tank 1 for storing hot water from the heater 2, and a hot water supply pump 31 for guiding the hot water in the hot water storage tank 1 to a predetermined hot water supply location. I have it. The three-way valve 4 is connected between the hot water supply pump 31 and the hot water storage tank 1, and the other inlet of the three-way valve 4 is connected to the heating tank 21.

[0006]

By switching the three-way valve 4, it is possible to selectively supply hot water from either the hot water storage tank 1 or the heating tank 21 to the hot water supply location. Therefore, even when the hot water storage tank 1 is washed, the hot water in the heating tank 21 can be used.

[0007]

Embodiment FIG. 1 is a piping system diagram showing a configuration of an embodiment of the present invention. The hot water storage tank 1 is a tank open to the atmosphere, and an overflow pipe 11 is connected to the upper portion thereof, and a drainage pipe 12 is connected to the bottom portion thereof. A flow switch 7 and a drain valve 12a are sequentially connected to the drain pipe 12. The capacity of the hot water storage tank 1 is about 350 to 1000 liters.

The heater 2 is composed of a hermetically sealed heating tank (capacity 50 liters) 21, an electric heater 22 arranged therein, a circulation pump 23 and the like. The discharge port of the circulation pump 23 communicates with a bottom position in the heating tank 21 via a check valve 25, and the suction port has an outgoing pipe 15 whose end communicates with the bottom position of the hot water storage tank 11. Are connected. In addition, an upper end of the heating tank 21 is connected to a return pipe 16 having an end communicating with an upper position in the hot water storage tank 1 and having a flow switch 6 in the middle thereof. By driving the pump 23, the water in the hot water storage tank 1 can be circulated through the heating tank 21.

Further, a water supply pipe 14 to which an electric valve 24, a flow rate sensor FS and a check valve 26 are sequentially connected is connected to a bottom position in the heating tank 21, and the water supply device 14 is connected to the water supply pipe 14. (Not shown) is connected. On the other hand, the hot water storage tank 1 is connected to a hot water supply pipe 13 which communicates with a bottom position inside thereof, and the hot water supply device 3 is connected to the hot water supply pipe 13.

The hot water supply device 3 has a structure in which a check valve 32, a pressure switch 33 and a flow switch 34 are sequentially connected to the discharge side of a pressurized water supply pump 31, and when a hot water supply tap (not shown) is opened. In addition, when the pressure switch 33 detects a pressure drop on the pump discharge side, the pump 31 is driven, and then the pressure switch 33 detects a pressure increase caused by closing the hot water tap, or the flow switch 34 It is configured to stop the drive of the pump when it is detected that the flow rate has fallen below the specified amount.

Further, in the hot water supply device 3, the electric three-way valve 4 is connected to the suction port of the pump 31, the hot water supply pipe 13 is connected to one connection port of the three-way valve 4, and the other connection port is connected to the other connection port. Is connected to an auxiliary hot water supply pipe 17 whose end communicates with the bottom position in the heating tank 21. Therefore, by switching the electric three-way valve 4, it is possible to selectively supply either the hot water in the hot water storage tank 1 or the hot water in the heating tank 21 to the hot water supply location.

Further, the hot water storage tank 1 and the heating tank 21 are provided with temperature sensors TH1 and TH2 for detecting the respective internal water temperatures. These sensors and the flow sensor FS of the preceding water supply pipe and the return pipe are provided. The output signals of the flow switches 6 and 7 of the drainage pipe are input to the control device 5. The control device 5 is configured to perform the drive control of the electric heater 22 and the circulation pump 23, the opening / closing control of the electric valve 24, the switching control of the electric three-way valve 4 and the like, which will be described later, based on these input signals. Has been done.

Next, the operation of the controller 5 and the operation of the embodiment of the present invention will be described. First, the control device 5 opens the electric valve 24 and calculates the supply amount to the heating tank 21 based on the detection value of the flow rate sensor FS, and the calculated value corresponds to the capacity of the heating tank 21, that is, 50 liters. When the temperature sensor TH2 detects that the water temperature of the heating tank 21 has reached the boiling temperature (85 ° C) due to this heating, the electric valve 24 is closed and the electric heater 22 is then driven. Then, the drive of the electric heater 22 is stopped, the electric valve 24 is opened again, and such an operation is repeated. As a result, the hot water boiled in the heating tank 21 is sequentially supplied to the hot water storage tank 1, and when the set volume of hot water is stored in the hot water storage tank 1, the boiling operation is completed. The boiling operation is performed during the midnight electricity rate.

Further, the control device 5 controls the drive of the electric heater 22 based on the output of the temperature sensor TH2 of the heating tank even after the above boiling operation is completed (after 7:00 am). Then, the water temperature in the heating tank 21 is maintained at the boiling temperature, and when the output of the temperature sensor TH1 on the hot water storage tank side shows the boiling temperature or less, the circulation pump 23 is driven and the sensor output is boiled. Stop the pump drive when the temperature rises. As a result, the temperature of the hot water in the hot water storage tank 1 is always kept at the boiling temperature.

Note that the circulation pump is stopped when the flow switch 6 is turned off even though the circulation pump is being driven. Here, during the above boiling and when using normal hot water, the flow path of the electric three-way valve 4 is set so as to connect the suction port of the pump 31 of the hot water supply device 3 and the outgoing pipe 13. Therefore, when using normal hot water, opening the hot water tap causes hot water from the hot water tank 1 to flow out from the hot water tap.

When the hot water storage tank 1 is washed, first, the drain valve 12a is opened to drain the water from the hot water storage tank 1. By this drainage, the flow switch 7 of the drain pipe 12 is removed. When is turned on, the control device 5 interlocks the drive of the circulation pump 23 and switches the electric three-way valve 4. By this valve switching, the suction port of the pump 31 of the water supply device 3 is communicated with the inside of the heating tank 21 through the auxiliary hot water supply pipe 17, and when the hot water tap of the hot water storage tank 1 is opened after the cleaning of the hot water storage tank 1 is started, the heating tank is heated. Hot water from 21 flows out from the hot water tap. Therefore, the hot water (50 liters) of the capacity of the heating tank 21 can be used even while the hot water storage tank 1 is being washed. Here, the washing of the hot water storage tank 1 is usually started after finishing filling the bathtub, so the amount of hot water used after the filling is not so large, and it is possible to use about 50 liters of hot water. It can respond sufficiently.

It should be noted that the drain valve 12 a is an electric valve, and when the controller 5 is instructed to wash the tank, the electric valve is configured to be opened and the washing water is supplied to the hot water tank 1. If it is configured to be controlled by the controller 5, it is possible to automate the tank cleaning. In this case, the flow switch 7 of the drainage pipe 12 need not be provided.

[0018]

As described above, according to the present invention, a three-way valve is connected between the hot water storage tank and the pump of the water heater, and the other inlet of this three-way valve is connected to the heating tank of the heater. Therefore, the hot water from the heating tank can be supplied to the hot water supply location by switching the three-way valve at the start of cleaning the hot water storage tank, which allows the hot water to be used even when cleaning the hot water storage tank. It becomes possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, showing a piping system diagram and a block diagram of a control system together.

[Explanation of symbols]

 1 ... ・ Hot water storage tank 11 ・ ・ ・ Overflow pipe 12 ・ ・ ・ ・ Drainage pipe 12a ・ ・ ・ ・ Drainage valve 2 ・ ・ ・ ・ ・ ・ Heating device 21 ・ ・ ・ ・ ・ ・ Heating tank 22 ・ ・ ・ ・ ・ ・ Electric heater 3 ··· Hot water supply device 31 ··· Pressurized water supply pump 4 ··· Electric three-way valve 5 ··· Control device

Claims (1)

[Scope of utility model registration request] 1. A heater comprising a heating tank and an electric heater arranged inside the tank, an atmosphere open type hot water storage tank for storing hot water from the heater, and a predetermined amount of hot water in the hot water storage tank. Is equipped with a hot water supply pump that leads to the hot water supply location, and a three-way valve is connected between the hot water supply pump and the hot water storage tank, and the other inlet of the three-way valve is connected to the heating tank. Water heater.