JPH11141710A - Safety valve for hot water reserving container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To beforehand avoid bursting accident of a hot water reserving container and burning accident caused by excessively hot water by arranging a sluice valve in a valve case arranged on a hot water drain port in a hot water reserving container, and open the sluice valve in the case where pressure of reserved hot water reaches prescribed pressure or a temperature of reserved hot water reaches a prescribed temperature. SOLUTION: When a current carrying time control power supply circuit is turned on at a time zone utilizing midnight power, current carrying to an electric heater is started, and water in the hot water reserving container 1 is heated. When a temperature of hot water in the container 1 reaches a prescribed temperature, current carrying to the electric heater is stopped. When an accident in which current carrying is not broken for any causes is generated, a hot water temperature is raised. After that, when the hot water temperature reaches a setting temperature of a safety valve 20 and when the hot water temperature exceeds a transformation temperature of a temperature spring 38, a sluice valve 31 is pushed in an upper direction by elastic force of the temperature spring 38, and is opened. As a result, excessive hot water flows out through a hot water drain piping 12 by water pressure from a water pipe, and simultaneously, hot water in the container 1 is cooled by normal temperature water supplied from the water pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method for opening a gate valve housed in a valve case mounted on a hot water storage container when the pressure or temperature in the hot water storage container such as a regenerative electric water heater rises to a predetermined value. The present invention relates to a hot water container safety valve that discharges hot water from a hot water container and avoids an accident of the hot water container.

[0002]

2. Description of the Related Art As an example of effective use of surplus power at night,
Conventionally, regenerative electric water heaters have been put to practical use. In general, this type of regenerative electric water heater has an adiabatic heat-insulating structure for the hot water storage tank and an electric heater inside the tank in order to heat and store hot water by energizing during the time when the total power consumption of the day decreases. The hot water storage tank is provided with a water supply port and a hot water supply port.

The above-mentioned electric water heater is provided with a temperature control switch for shutting off the supply of electric power when the hot water reaches a predetermined hot water temperature during the energization time, and avoids abnormal overheating. If the control switch fails and the power is continuously supplied, the hot water in the bath exceeds the set temperature and finally boils. For this reason, conventionally, boiling steam is discharged from a pressure sensing type steam release safety valve formed at the base of the hot water supply port, and control is performed so that the internal pressure in the tank does not exceed a predetermined value. When the failure of the temperature control switch is restored after the safety valve is operated, the hot water exceeding the set value is stored in the hot water tank and maintained. In other words, if hot water is used from this state, hot water that is higher than usual will blow out from, for example, a shower,
Needless to say, it is very dangerous. Therefore, when either the temperature or the pressure in the electric water heater rises to a predetermined value as described above, the valve of the pressure vessel of the water heater is automatically opened, and the safety of the water heater for the purpose of ensuring its safety is improved. The invention of Japanese Patent Application Laid-Open No. Hei 7-180911 concerning the device is known.

In the above-described conventional safety device for a water heater, a valve 54 housed in a valve case 51 mounted on a pressure vessel 68 is pressed against a valve seat 56 by a pressure spring 55 as shown in FIG. Push-up pin 6 of sensor 60
When the temperature inside the pressure vessel 68 rises to a predetermined value, the push-up pin 62 pushes up the valve 54 to open it, and the upper end of the temperature sensor 60 is closed by the lid 67. And a thermally expandable fluid such as a push-up pin mounting member 53, a bias spring 64, a piston 65, and oil 66. As another example, as shown in FIG.
The temperature sensor 60 is configured to house a push-up pin 62, a push-up pin mounting member 53, a bias spring 64, and a shape memory alloy spring 70 therein.

In the water heater of FIG. 5, for example, when the temperature rises to a predetermined value, a heat-expandable fluid such as oil 66 in the temperature sensor 60 expands to push up the push-up pin 62 and to open the valve 54 of the pressure vessel 68. When opened, the temperature or pressure does not rise above a predetermined value, and safety can be achieved. When the pressure is sensed, when the pressure exceeds a certain pressure, the pressure pushes up the valve 54 from below and overcomes the pressure spring 55 to open the valve 54.

As described above, in the conventional apparatus, the temperature sensing operating section and the pressure sensing operating section are separately provided, and the temperature sensing operating section further includes a push-up pin 62, a push-up mounting member 53, a bias spring 64, a pin strike 65, It must be made of oil 66 or the like, and has the drawbacks that the number of parts is large, the structure is complicated, there are many failures, and the cost is high.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a gate valve housed in a valve case is opened when the internal pressure of a hot water storage container rises above a predetermined value or when the temperature inside the hot water storage container is overheated to a predetermined value or more. Overpressure and superheated hot water can be discharged from the hot water storage container to avoid accidents in the hot water storage container and to ensure safety, and to reduce the number of parts of the drive unit of the gate valve to simplify the structure and reduce manufacturing costs. Provide a safety valve for a hot water storage container.

[0008]

According to the present invention, there is provided a safety valve for a hot water storage container, wherein a gate valve is provided in a valve case provided at a drain port of the hot water storage container. A safety valve for a hot water storage container that discharges hot water from the valve seat to the outside when the temperature reaches a predetermined temperature or when the temperature reaches a predetermined temperature, specifically, above a gate valve provided in the hot water discharge port. And the valve shaft is integrated with the gate valve on the lower side,
A pressure spring is mounted on one of the valve shafts, and a temperature spring is mounted on the other valve shaft. The safety valve for the hot water storage container is provided in a valve case provided in the hot water storage container. Also, as a temperature spring, the gate valve can be manually opened from the valve seat or pressed against the valve seat.
A shape memory alloy such as a nickel titanium alloy or the like is used. It consists of a pressure spring, and a safety valve for a hot water storage tank, which is equipped with a temperature spring on the lower shaft.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a safety valve for a hot water storage container according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an embodiment of the safety valve.
A hot water inlet port 22 connected to the hot water storage container 1 at one end;
The other end is provided between the hot water discharge port 35 and
A valve case 21 in which a valve seat 32 is formed in a valve chamber communicating between the two ports 22 and 35, and the valve case 21 is axially slidably supported through the valve seat 32 through the valve seat 32. The upper and lower valve shafts 26 and 29 are integrally formed, and a gate valve 3 for pressing or opening the valve seat 32 from above in the middle of the shafts.
1 is provided.

A pressure spring is provided on the valve shaft 26 above each of the valve shafts 26 and 29 which are provided integrally with the gate valve 31 and project from the upper and lower centers of the gate valve 31 so that the gate valve 31 can be pressed against the valve seat 32. The lower valve shaft 29 is provided with a shape memory alloy such as a nickel titanium alloy in a coil shape, and is provided at a temperature at which it is deformed under a set temperature condition so as to have a maximum elastic constant. A spring 38 is provided.

The elastic force of the temperature spring 38 is biased so that the elastic force of the temperature spring 38 is lower than that of the pressure spring 39 in a low temperature atmosphere, while the elastic force of the temperature spring 38 is lower in a high temperature atmosphere. The temperature is urged so as to be larger than the elastic force of the pressure spring 39. Further, a lever-type valve opening handle 40 is raised and lowered via a pin 42 at an end of a valve shaft 26 from which a shaft hole provided in an upper lid member 24 fixed to one end of the valve case 21 is projected. Provided as
The gate valve 31 can be manually opened from the valve seat 32 through the valve shaft 26 by the lifting action of the cam portion 41, and the manual valve opening state is shown in FIG. That is, in this state, the valve shafts 26 and 29 and the gate valve 31 move upward integrally.

Next, an example in which the safety valve 20 for a hot water storage container of the present invention shown in FIG. 1 is attached to the hot water storage container 1 of the reheatable electric water heater shown in FIG. 3 and applied as a safety device will be described. The regenerative electric water heater comprises a hollow cylindrical hot water storage container 1 having a plastic inner tank 4 inside a polybutylene outer tank 2 via a heat insulating material 3.

The hot water storage container 1 is provided with a water supply port 5, a hot water supply port 6, and a hot water discharge port 7 communicating with an inner cavity. The water supply port 5 is connected to a water supply pipe 9 through a check valve 8.
The hot water supply port 6 is connected and connected to a hot water supply side pipe 11 via a check valve 10. The hot water supply port 7 is connected to and connected to the hot water discharge pipe 12 via the hot water storage container safety valve 20 of the present invention.

An electric heater 1 is provided in the inner cavity of the hot water storage container 1.
And a temperature sensor 15 protruding from the inner cavity of the heat exchanger 13.
The ON / OFF drive of the temperature control switch circuit 17 provided in the power supply time control power supply circuit 16 is performed. That is, when the temperature of the hot water in the hot water storage container 1 exceeds a preset temperature (for example, about 90 ° C.), the temperature control switch circuit 17 controls the electric heater 14 even when the power-on time control power supply circuit 16 is within the power-on time. It is structured to cut off the current.

The hot water container safety valve 20 has a valve structure as shown in FIG. 1. The valve case 21 has a substantially cylindrical structure, and a male screw is screwed around the base end of the hot water container. The mount screw 23 of the hot water inflow side port 22 that is screwed to the first hot water discharge port 7 is configured. An upper lid member 24 is screwed and fixed to the upper end of the valve case 21, and the upper and lower shaft holes formed in both the axial centers of the upper lid member 24 and the shaft support wall 25 of the hot water inflow side port 22 respectively have a center. The upper and lower ends of the valve shafts 26 and 29 in which a disc-shaped valve disc 28 is fixedly provided at the upper and lower ends are provided so as to be slidably inserted in the axial direction.

A rubber ring 30 is fitted on the lower surface of the outer peripheral portion of the valve panel 28 to form a gate valve 31. An annular valve seat 32 facing the rubber ring 30 is provided at the center of the valve case 21. And the inner valve chamber 33 by the gate valve 31.
A water / water discharge port 35 communicating with the outer valve chamber 34 protrudes from the side of the valve case 231, and a pipe connection screw 36 is screwed at an end thereof.

The shaft supporting wall 25 has a hot water inlet side port 2.
A large number of small holes 37, 37 ... communicating with the inner valve chamber 33 are formed. A temperature spring 38 extrapolated to the valve shaft 29 is elastically provided between the shaft support wall 25 and the valve plate 28. A pressure spring 39 externally attached to the valve shaft 26 is elastically mounted between the valve disc 28 and the upper lid member 24. A lever-shaped valve-opening handle 40 slidably contacting the cam portion 41 with the surface of the upper lid member 24 is pivotally attached to the end of the valve shaft 26 projecting from the shaft hole of the upper lid member 24 via a bin 42 so as to be able to move up and down. The gate valve 31 is retracted and opened from the valve seat 32 via the valve shaft 26 by the lifting action of the cam portion 41.

In the drawing, reference numeral 43 denotes a spring receiver, and reference numeral 44 denotes a rubber seal inserted between the spring receiver 43 and the upper lid member 24. The temperature spring 38 is formed by spirally winding a shape memory alloy such as a nickel-titanium alloy into a coil shape and deforming under a set temperature condition (for example, T2 = about 95 ° C.) to have a maximum elastic constant and exhibit a large elastic force. Under the set temperature condition T2, the elastic force of the temperature spring 38 becomes larger than the elastic force of the pressure spring 39, and pushes the gate valve 31 in the direction of arrow A to retreat and open from the valve seat 32. .

Further, under a temperature condition lower than the set value T2,
Since the elastic force of the temperature spring 38 is smaller than the elastic force of the pressure spring 39, the pressure spring 39 presses the gate valve 31 in the direction opposite to the direction of arrow A in FIG.
1 is kept plugged. As shown in FIG. 3, the hot water storage container safety valve 20 having the above configuration is attached to a hot water discharge port 7 provided in the hot water storage container 1 of the electric water heater, and is connected to the hot water storage port 1. It is provided at a location where the hot water temperature can be appropriately reflected according to the temperature distribution characteristics inside the tank, such as the upper surface or side surface of the tank.

As shown in FIG. 4, the energization time control power supply circuit 16 is set to be "ON" during a time period during the day when the total power consumption is reduced (for example, from 11 pm to 6 am). Therefore, the power-on time control power supply circuit 16 is automatically turned “ON” at 11:00 pm. At this time, since the temperature of the hot water in the hot water storage container 1 input from the temperature sensor 15 to the temperature switch control circuit 17 is lower than the set temperature T1, the temperature switch control circuit 17 is in the [ON] state, and the heat exchange is performed. The electric heater 14 of the vessel 13 is electrically heated.

The water in the hot water storage container 1 is heated by this energization, but the temperature T of the hot water gradually rises due to the heat insulation effect of the outer tub 2 and the inner tub 4 in which the hot water storage container 1 sandwiches the heat insulating material 1. Generally, the electric heater 14 corresponds to the capacity of the hot water storage container 1.
Is set at a predetermined temperature T1 before the energization time control power supply circuit 16 is turned "OFF".
, The temperature sensor 15 detects this hot water temperature and turns off the temperature control switch circuit 17.

However, if an accident occurs that the temperature control switch circuit 16 remains "ON" for some reason (for example, part B in FIG. 4), the electric heater 14 continues to generate heat and the temperature of the hot water in the tank becomes lower. Keep rising. Here, when the hot water temperature reaches the operation set temperature (temperature at which the temperature spring 38 is deformed and energized) T2 of the hot water storage container safety valve 20, the hot water storage safety valve 20 is turned on.
Opens the valve.

That is, the safety valve 20 for the hot water storage container has a structure in which the temperature spring 38 is in the inner valve chamber 33 and is immersed in the hot water in the hot water storage container 1, so that when the temperature of the hot water increases, the ambient temperature increases. If the temperature exceeds the transformation temperature T2, the temperature spring 38
Is greater than the elastic force of the pressure spring 39, the gate valve 31 is pressed in the direction of arrow A in FIG. 1 to retreat from the valve seat 32, and the valve is opened.

For this reason, the superheated hot water in the hot water storage container 1 flows out to the hot water discharge piping 12 through the outer valve chamber 34 of the hot water storage container safety valve 20 by the water pressure from the water supply pipe 9, and is supplied into the hot water storage container 1. The superheated water in the hot water storage container 1 is diluted by the normal temperature water from the supplied water pipe 9. For this reason, it is possible to avoid secondary accidents such as a burst accident of the hot water storage container 1 and a burn accident due to use of overheated hot water.

When the temperature of the hot water drops due to the water supply action in the hot water storage container 1 and the ambient temperature of the temperature spring 38 becomes lower than the set value T2, the elastic force of the temperature spring 38 becomes smaller than the elastic force of the pressure spring 39, The spring 39 presses the lid gate valve 31 in a direction opposite to the direction of the arrow A in FIG. 1 to come into close contact with the valve seat 32 and maintain the valve in the stoppered state. Further, the supply of the room temperature water from the water supply pipe 9 is stopped by closing the safety valve 20 for the hot water storage container.

In order to manually discharge the superheated hot water from the hot water discharge pipe 12, as shown in FIG. 2, the lever-type valve opening handle 40 is raised in the direction of arrow C with the pin 42 as the center. When the lever-type valve opening handle 40 is raised, the cam portion 41 slides on the surface of the upper lid member 24, and the pressure spring 39
Act to lift the valve shaft 26 against the elasticity of the valve shaft 26.
For this reason, the gate valve 31 retreats from the valve seat 32 and opens,
The superheated hot water is discharged from the hot water discharge port 35 by the internal pressure.

[0027]

According to the safety valve for a hot water storage container of the present invention described above, when the internal pressure of the hot water storage container rises to a predetermined value or more, or when the temperature in the hot water storage container is overheated to a predetermined value or more, the valve case is closed. The stored gate valve is automatically opened to overpressure,
The superheated hot water is discharged from the hot water storage container, so that a burst accident of the hot water storage container and a burn accident due to the superheated hot water can be avoided.

Further, in the safety valve for a hot water storage container of the present invention, the built-in gate valve is connected to the valve seat at a preset temperature condition by a temperature spring of a shape memory alloy such as a nickel titanium alloy and a normal pressure spring. When the hot water in the hot water storage container is overheated due to some accident, the valve opens by the elastic force of the temperature spring of the shape memory alloy, and the superheated water can be discharged. High reliability to safety.

Further, the safety valve for a hot water storage container according to the present invention is composed entirely of mechanical parts, uses a temperature spring made of a shape memory alloy for the temperature control section, and furthermore, uses the temperature spring and the pressure on the valve shaft which moves together. Since the spring is provided, the number of parts can be reduced as compared with a conventional safety device of this type, the structure can be simplified, and the manufacturing cost can be reduced.

Further, since the valve shafts 26 and 29 and the gate valve 31 move up and down in an integrated structure, not only the number of parts is small, but also
Therefore, there is an effect that the number of failures is small and the manufacturing cost is low.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a main part of a hot-water storage container safety valve according to an embodiment of the present invention when the valve is closed.

FIG. 2 is a side sectional view of a main part of the state when the safety valve of FIG. 1 is manually opened.

FIG. 3 is a schematic piping diagram in which the safety valve of FIG. 1 is attached to a hot water storage container of a regenerative electric water heater and applied as a safety device.

FIG. 4 is a timing chart showing the relationship between the hot water temperature in the tank of the electric water heater and the time showing the operation of the safety valve of the present invention in FIG.

FIG. 5 is a side sectional view of a conventionally known safety device for a water heater.

FIG. 6 is a side sectional view of a temperature sensor of another conventional safety device different from FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hot-water storage container 20 Safety valve for hot-water storage containers 21 Valve case 22 Hot water inlet side port 26 Valve shaft 29 Valve shaft 31 Gate valve 32 Valve seat 38 Temperature spring 39 Pressure spring

Claims (6)

[Claims] A gate valve is provided in a valve case provided in a hot water discharge port of a hot water storage container, and the gate valve separates from a valve seat when the hot water reaches a predetermined pressure or a predetermined temperature. Safety valve for hot water storage container that discharges hot water from the hot water discharge port to the outside. 2. A valve shaft is mounted integrally with a gate valve on the upper and lower sides of a gate valve provided at a hot water discharge port, and a pressure spring is provided on one valve shaft, and a temperature spring is provided on the other valve shaft. A safety valve for a hot water storage container that is mounted and stored in a valve case provided in the hot water storage container. 3. The safety valve for a hot water storage container according to claim 1, wherein the gate valve can be manually opened from the valve seat or pressed against the valve seat. 4. The safety valve for a hot water storage container according to claim 2, wherein a shape memory alloy such as a nickel titanium alloy is used as the temperature spring. 5. The safety valve for a hot water storage container according to claim 2, wherein the elastic force of the pressure spring is always larger than the elastic force of the temperature spring to press the gate valve against the valve seat. 6. The safety valve for a hot water storage container according to claim 2, wherein a pressure spring is mounted on an upper valve shaft of the gate valve, and a temperature spring is mounted on a lower shaft of the gate valve.