JP2014178084A - Hot water storage type electric water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make water in a tank easily usable in an emergency when water is not supplied in unexpected suspension of water supply, disaster and the like.SOLUTION: A hot water storage type electric water heater includes: a hot water storage tank in which an electric heater is provided; a water supply pipe for guiding water from a water supply source to the hot water storage tank; a hot water tapping pipe for guiding hot water and water in the hot water storage tank to a water discharge part; a first check valve provided at the hot water tapping pipe; a by-pass pipe for connecting a bottom part of the hot water storage tank and the hot water tapping pipe which is on further downstream side than the first check valve; a pump provided in the by-pass pipe and conveying the hot water and water to the hot water tapping pipe; pressure measurement means for measuring pressure on the downstream side of the pump; and a control unit for controlling the pump. The control unit operates in such a manner that, when a measurement value of the pressure measurement means is below a predetermined pressure, it operates the pump, and when the measurement value of the pressure measurement means is equal to or greater than the predetermined pressure, it stops the operation of the pump.

Description

  The present invention relates to a hot water storage type electric water heater for a faucet installed in a washroom or the like.

2. Description of the Related Art Conventionally, it is known that there is a technique for taking out water stored in a tank in order to use water in a water storage tank for drinking water or various uses in an emergency.
For example, the water supply system of Patent Document 1 includes water storage means such as a water storage tank, and is used to supply tap water supplied from a water supply pipe to a water tap in a house. The water supply pipe is provided with a check valve for preventing tap water from flowing back to the water supply pipe. The first water distribution pipe supplies tap water downstream from the check valve to the first water faucet. Further, the second water distribution pipe supplies tap water downstream of the check valve to the second water faucet. The first water faucet is normally used as a normal water faucet, but is also used as an emergency water intake faucet in an emergency when the feed water pressure does not act on tap water. Moreover, a connection port is formed in the second water faucet, and a pressurizing device is attached to the connection port. And the tap water stored by the water storage means can be taken out from the emergency water tap by operating the pressurizing device to pressurize the water storage means.

JP 2010-185272 A

  However, in the technique of Patent Document 1, in order to take out the tap water stored in the water storage means in an emergency, the pressurizing device is carried to the vicinity of the second water tap, and the pressurizing device is connected to the connection port of the second water tap. It is necessary to perform the attachment work by connecting the water and pressurize the water storage means. For this reason, in a situation where there is no room for emergency, there is a problem in practicality because complicated work must be performed.

  In order to achieve the above object, a first invention provides a hot water storage tank provided with an electric heater, a water supply pipe for guiding water from a water supply source to the hot water storage tank, and guides hot water in the hot water storage tank to a water discharge section. A hot water pipe, a first check valve provided in the hot water pipe, a bypass pipe connecting the bottom of the hot water storage tank and the hot water pipe downstream from the first check valve, and provided in the bypass pipe A bypass pipe pump for conveying hot water to the outlet pipe, pressure measuring means for measuring the pressure on the downstream side of the bypass pipe pump, and a control unit for controlling the bypass pipe pump. Activates the bypass pipe pump if the measured value of the pressure measuring means is less than a predetermined pressure, and stops the operation of the bypass pipe pump if the measured value of the pressure measuring means is equal to or greater than a predetermined pressure. Control A hot water storage type electric water heater according to claim.

  According to the first invention, even in the case of an emergency when water is not supplied unexpectedly, such as in the event of an unexpected water outage or a disaster, if the water tap is discharged during water outage, the bypass pipe pump is activated and pumps up hot water in the hot water storage tank Therefore, the hot water in the hot water storage tank can be discharged by a normal water discharge operation without requiring a complicated operation. That is, until the hot water in the hot water storage tank runs out, the hot water can be used by a normal water discharge operation. Further, the water pumped up by the bypass pipe pump by the first check valve does not return into the tank. Therefore, water is supplied to the faucet and discharged from the water faucet in both cases of normal time and water outage.

  According to a second invention, in the first invention, the bypass pipe pump includes a first pump and a second pump provided in parallel with the bypass pipe, and the first pump and the second pump Is a hot water storage type electric water heater characterized in that one is a non-rotating pump and the other is a rotating pump.

  According to the second invention, the rotary pump and the non-rotary pump are installed in parallel, so that the head (flow rate) is secured with the rotary pump, and the pressure is secured with the non-rotary pump, so that it is compact. The water in the hot water storage tank can be taken out with a simple structure and low power consumption. Note that either the rotary pump or the non-rotary pump alone is large and consumes a large amount of power.

  A third invention is the hot water storage type electric water heater according to the first or second invention, wherein the hot water storage type electric water heater has an internal power source for moving the bypass pipe pump.

  According to the third invention, in an emergency such as a water outage, the supply of electricity for operating the pump may stop. At that time, the remaining water in the hot water storage tank can be taken out by operating the pump using the internal power supply built in the hot water storage type electric water heater.

  According to the aspect of the present invention, the water in the hot water storage tank can be easily used in an emergency in which water is not supplied, such as in the event of unexpected water interruption or disaster.

It is a lineblock diagram of a hot water storage type electric water heater concerning one embodiment of the present invention. It is a figure which shows the detection pressure in the pressure measurement means which concerns on one Embodiment of this invention. It is a flowchart figure which concerns on one Embodiment of this invention. It is a block diagram of the hot water storage type electric water heater which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of a hot water storage type electric water heater 1 according to an embodiment of the present invention.
As shown in FIG. 1, the hot water storage type electric water heater 1 includes a water supply pipe 19 that supplies water from a water supply source (not shown) to a hot water storage tank 2 through a water supply port 15, and an upstream in the middle of the water supply pipe 19. A third check valve 13 and a pressure reducing valve 6 provided in order from the side (water supply port 15 side), a water discharge pipe 21 branched from the water supply pipe 19 on the downstream side of the pressure reducing valve 6, and connected to the water outlet 17. It has.

  The third check valve 13 is for preventing the hot water in the hot water storage tank 2 from flowing backward to the water supply source when the water is shut down, and the pressure reducing valve 6 reduces the water pressure flowing into the hot water storage tank 2 to a substantially constant value (for example, , 0.08 MPa or less).

  The hot water storage type electric water heater 1 includes a hot water pipe 20 that connects the upper part of the hot water storage tank 2 and the hot water outlet 16, a first check valve 11 provided in the middle of the hot water pipe 20, and a first check valve. 11, an expansion water discharge pipe 22 branched from the hot water discharge pipe 20 on the upstream side of the hot water storage tank 2 and connected to the expansion water discharge port 18, and a negative pressure valve provided in the middle of the expansion water discharge pipe 22 And a relief valve 7.

  Further, the relief valve 7 with a negative pressure valve discharges the expanded water in the hot water storage tank 2 volume-expanded by the electric heater 3 built in the hot water storage tank 2 through the expanded water discharge pipe 22, and reduces the pressure in the hot water storage tank 2. The pressure is set to be substantially constant (for example, 0.1 MPa or less), and if the pressure in the hot water storage tank 2 becomes negative, the built-in negative pressure valve is opened, and the expanded water is discharged from the expanded water discharge port 18. This is for taking outside air into the hot water storage tank 2 via the pipe 22.

  Further, the hot water storage tank 2 is provided with temperature measuring means 4 for measuring the hot water temperature in the hot water storage tank 2 and water level measuring means 5 for measuring the water level in the hot water storage tank 2.

  Water from a water supply source (not shown) enters the hot water storage type electric water heater 1 through the water supply port 15 and is depressurized by the pressure reducing valve 6 through the water supply pipe 19. Then, the water that has passed through the pressure reducing valve 6 is supplied to the hot water storage tank 2 and is supplied from the water outlet 17 to the water tap 14 via the water outlet pipe 21.

  The water supplied to the hot water storage tank 2 is supplied to the hot water storage tank 2 by the control unit 24 so that the hot water temperature in the hot water storage tank 2 measured by the temperature measuring means 4 becomes the set temperature set by the operation unit 25. Heated by the built-in electric heater 3.

  When the water tap 14 is opened for the user to use hot water, the hot water in the hot water storage tank 2 passes through the hot water outlet pipe 20 and is supplied to the water tap 14 through the hot water outlet 16. At that time, it is mixed with the water through the water outlet 17 at the water tap 14 and adjusted to a desired temperature.

  The hot water storage type electric water heater 1 includes a bypass pipe 23 that connects the bottom of the hot water storage tank 2 and the downstream side of the first check valve 11 provided in the hot water discharge pipe 20, and the bypass pipe 23 is connected to the upstream side. In order from the (bottom side of the hot water storage tank 2), flow rate limiting means 8 for limiting the flow rate of hot water passing through the bypass pipe 23 and the discharge pressure of a bypass pipe pump 9 to be described later are prevented from flowing backward to the hot water storage tank 2 side. For measuring the pressure in the bypass pipe 23 pressurized by the bypass pipe pump 9, the bypass pipe pump 9 for pumping hot water in the hot water storage tank 2 to the faucet 14 when the water is shut off Pressure measuring means 10.

  The flow restricting means 8 is configured by reducing a part or all of the inner diameter of the constant flow valve or the bypass pipe 23 set to a low flow rate, and the flow rate flowing through the bypass pipe 23 at the time of normal water discharge when no water break has occurred. The pressure loss due to the second check valve 12 and the bypass pipe pump 9 provided in the bypass pipe 23 is also added, which is smaller than the flow rate flowing through the hot water pipe 20.

  Accordingly, a small amount of hot water having a low temperature is discharged from the water faucet 14 via the bypass pipe 23 from the bottom of the hot water storage tank 2 even during normal water discharge when no water break has occurred. There is almost no drop in the temperature of hot water supplied to the water tap 14 via the pipe 20, and there is no problem in using hot water.

  The hot water pumped up by the bypass pipe pump 9 by the first check valve 11 does not return into the hot water storage tank 2. On the other hand, when a water discharge operation is performed in a normal time when water is always supplied from a water supply source, hot water in the hot water storage tank 2 is mainly supplied to the water tap 14 via the hot water discharge pipe 20 and discharged therefrom. .

  Further, instead of the flow rate control means 8, the flow rate flowing through the bypass pipe 23 may be adjusted by adjusting a coil spring (not shown) built in the second check valve 12.

FIG. 2 is a diagram showing the detected pressure in the pressure measuring means 10 according to one embodiment of the present invention.
When the hot water side of the water tap 15 is opened at the time of water interruption, the pressure measured by the pressure measuring means 10 gradually decreases. And if it becomes below a predetermined value (for example, 0.05 MPa) defined beforehand, bypass pipe pump 9 will actuate, hot water in hot water storage tank 2 will be pumped up, and it will be discharged from water tap 14.

  At this time, since the negative pressure valve of the relief valve 7 with the negative pressure valve is automatically opened and the outside air is taken in, the hot water in the hot water storage tank 2 is pumped up to the water tap 14 without damaging the hot water storage tank 2. Then, when the water tap 14 is closed, the pressure in the bypass pipe 23 increases, and the bypass pipe pump 9 stops when it exceeds a predetermined value (for example, 0.05 MPa).

Next, the operation of the bypass pipe pump 9 at the time of water stop will be described in detail.
FIG. 3 is a control flow of the bypass pipe pump 9.

  First, it is determined whether or not the water level in the hot water storage tank 2 is equal to or higher than a predetermined value (step S1), and if it is equal to or higher than the predetermined value, it is determined whether or not the pressure in the bypass pipe 23 is equal to or lower than a predetermined value (step). S2). And if it is below a predetermined value by step S2, the bypass pipe pump 9 will be operated by the control part 24 (step S3). On the contrary, if it exceeds the predetermined value, the bypass pipe pump 9 is stopped (step S4).

  If it is determined in step S1 that the water level in the hot water storage tank 2 is less than the predetermined value, the bypass pipe pump 9 is stopped in step S4. Hereinafter, it repeats from step S1.

  In step S1, it is determined whether or not the hot water storage tank 2 is empty or close to the water level measuring means 5, and if it is less than a predetermined value, the bypass pipe pump 9 is stopped, The bypass pipe pump 9 is prevented from idling.

  Further, by controlling the electric heater 3 based on the water level in the hot water storage tank 2 measured by the water level measuring means 5, when the electric heater 3 is exposed from the water by pumping up by the bypass pipe pump 9, the electric heater 3 is turned off. Stops to prevent airing.

  Accordingly, the water breakage is detected based on the pressure in the bypass pipe 23 and the bypass pipe pump 9 is automatically operated to pump the hot water in the hot water storage tank 2 to the water tap 14. Until there is no hot water in the tank, the hot water in the hot water storage tank 2 can be used.

  In addition, the control unit 24 includes an internal power source (not shown) composed of a battery, a capacitor, and the like, and the supply of electricity (commercial power) for operating the bypass pipe pump 9 is stopped in an emergency such as a water outage. In this case, the remaining hot water in the hot water storage tank can be taken out by operating the bypass pipe pump 9 using the internal power source.

FIG. 4 is a configuration diagram of a hot water storage type electric water heater 1 according to another embodiment.
In the embodiment shown in FIG. 4, in place of the single bypass pipe pump 9 in the embodiment shown in FIG. 1, two units of a first pump 27a and a second pump 27b provided in parallel are provided. 1 is different from the embodiment shown in FIG. Specifically, a first pump 27 a is provided downstream of the second check valve 12 of the bypass pipe 23 and upstream of the pressure measuring means 10, and the second check valve of the bypass pipe 23 is also provided. A branch pipe 26 is provided on the downstream side of the valve 12 and upstream of the pressure measuring means 10 so as to communicate the upstream side and the downstream side of the first pump 27a. A dual pump 27b is further provided. One of the first pump 27a and the second pump 27b is a non-rotating pump and the other is a rotating pump.

  By using a rotary pump with a high lifting capacity together with a non-rotating (diaphragm) pump with a high pressurizing capacity, the head (flow rate) is secured with the rotary pump and the pressure is secured with the non-rotating pump. Thus, compared with the case where the head (flow rate) and pressure are ensured by only one rotary pump or non-rotary pump, low power consumption and compactness are realized.

  The internal power supply (not shown) provided in the control unit 24 is used when electricity (commercial power) for operating the first pump 27a and the second pump 27b is stopped in an emergency such as a water outage. However, the remaining hot water in the hot water storage tank can be taken out by operating the first pump 27a and the second pump 27b using the internal power source.

DESCRIPTION OF SYMBOLS 1 ... Hot water storage type electric water heater 2 ... Hot water storage tank 3 ... Electric heater 4 ... Temperature measuring means 5 ... Water level measuring means 6 ... Pressure reducing valve 7 ... Relief valve with negative pressure valve 8 ... Flow restricting means 9 ... Bypass pipe pump 10 ... Pressure measuring means 11 ... First check valve 12 ... Second check valve 13 ... Third check valve 14 ..Water faucet (water discharge part)
DESCRIPTION OF SYMBOLS 15 ... Water inlet 16 ... Outlet 17 ... Outlet 18 ... Expansion water discharge 19 ... Supply pipe 20 ... Outlet pipe 21 ... Outlet pipe 22 ... Expansion water Discharge pipe 23 ... Bypass pipe 24 ... Control part 25 ... Operating part 26 ... Branch pipe 27a ... First pump 27b ... Second pump

Claims (3)

A hot water storage tank equipped with an electric heater;
A water supply pipe for guiding water from a water supply source to the hot water storage tank;
A hot water outlet pipe for guiding hot water in the hot water storage tank to a water discharge part;
A first check valve provided in the tapping pipe;
A bypass pipe connecting the bottom of the hot water storage tank and the hot water pipe downstream from the first check valve;
A bypass pipe pump provided in the bypass pipe for conveying hot water to the hot water pipe;
Pressure measuring means for measuring the pressure downstream of the bypass pipe pump;
A control unit for controlling the bypass pipe pump;
With
The control unit activates the bypass pipe pump if the measured value of the pressure measuring means is less than a predetermined pressure, and if the measured value of the pressure measuring means is equal to or higher than the predetermined pressure, A hot water storage type electric water heater characterized by controlling the operation to stop.   The bypass pipe pump is composed of a first pump and a second pump provided in parallel with the bypass pipe. One of the first pump and the second pump is a non-rotating pump, and the other is The hot water storage type electric water heater according to claim 1, wherein is a rotary pump.   The hot water storage type electric water heater according to claim 1 or 2, further comprising an internal power source for moving the bypass pipe pump.