JPH0285579A - Circulating fluid leakage preventing device and cutoff valve - Google Patents

Abstract

PURPOSE:To purely mechanically close valves and improve reliability by connecting a one-way cutoff valve closed when the pressure difference between the upstream side and the downstream side becomes the preset value or above and a check valve nearby. CONSTITUTION:The pressure difference is ordinarily less than the preset value, a one-way cutoff valve 13a is kept open by the excitation of springs 13D and 13E, and the circulation of a fluid in a fluid circulating path 13F is assured. When the leakage of the fluid occurs, the pressure difference becomes the preset value or above due to the leakage of the fluid, the one-way cutoff valve 13a in a cutoff valve 13 located on the upstream side of the leakage occurrence section is closed against the excitation, and the flow of the fluid to the leakage occurrence section is prevented. On the other hand, a check valve 13b in a cutoff valve 13 located on the downstream side of the leakage occurrence section is closed, and the counterflow of the fluid to the leakage occurrence section is prevented. The valves are purely mechanically closed to prevent the leakage of the fluid, thus reliability can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to, for example, cooling equipment that performs cooling by configuring a heat pipe that circulates a refrigerant such as fluorocarbon between a condenser and an indoor unit, and Refrigerant piping for configuring the heat pipe of a heating equipment that performs heating by configuring a heat pipe that circulates refrigerant between a container and an indoor unit, or circulating hot water between a hot water generator and an indoor unit. If leakage of circulating fluid occurs in fluid circulation paths such as hot water piping for heating, various hydraulic piping, etc. due to poor sealing at the joint or cracks in the piping, etc., the flow of circulating fluid to the leakage point will be prevented. The present invention relates to a device that prevents all of the fluid in a fluid circulation path from leaking out, and a shutoff valve used therein.

To further describe the circulating fluid leakage prevention device, a cutoff valve is installed at each of multiple locations in the fluid circulation path to automatically shut off the fluid circulation path when the differential pressure between the upstream side and the downstream side exceeds a set value. related to something.

[Conventional technology]

Conventional circulating fluid leakage prevention devices, for example, devices that are applicable to refrigerant piping for heat pipe configurations described above, are equipped with a differential pressure detection sensor that detects the differential pressure that increases due to refrigerant leakage, and are used as shutoff valves. , a solenoid valve was provided that closed based on the detection of a differential pressure greater than a set value by the differential pressure detection sensor.

[Problem to be solved by the invention]

However, when using the above-mentioned conventional technology, the solenoid valve lacks reliability because it has the possibility of causing not only mechanical troubles but also electrical troubles such as wire breakage, electrical circuit failure, and power outages. There were some drawbacks. the result,
For example, when applied to refrigerant piping for the heat pipe configuration of cooling and heating equipment using heat pipes as described above, the length of the refrigerant piping is generally very long in order to supply refrigerant to a large number of indoor units installed on each floor. As a result, the amount of refrigerant becomes large, so if the shutoff valve does not operate when refrigerant leaks, a large amount of refrigerant will fill the room. As a result, although the refrigerants themselves are not toxic, they can cause oxygen deficiency accidents.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks.

[Means to solve the problem]

The characteristic configuration of the circulating fluid leakage prevention device according to the present invention is that the shutoff valve is biased to move in the opening direction, and when the differential pressure between the upstream side and the downstream side exceeds a set value, A one-way shutoff valve and a check valve, which close against an urging force using a driving force of a pressure difference greater than a set value, are connected in close proximity to each other.

The above-mentioned shutoff valve includes two valve bodies provided in the valve box, and an urging means for moving and urging the valve bodies in the closing direction, and a biasing means for moving and urging the valve bodies in the closing direction, and a biasing means for moving and urging the valve bodies in the closing direction, and a biasing means for moving the valve bodies in the closing direction, and a biasing means for moving the valve bodies in the closing direction. a first operating means for closing one of the valve bodies at a differential pressure that is equal to or greater than a set value; Preferably, the shutoff valve is provided with a second operating means that closes the other valve body using a pressure difference.

[For production]

By setting the set value to be the normal differential pressure, the one-way shutoff valve is held open by biasing when the differential pressure is less than the set value. Therefore, during normal times, fluid circulation in the fluid circulation path is guaranteed. When a fluid leak occurs, the one-way shutoff valve resists the pressure in the shutoff valve located upstream of the leakage point because the differential pressure exceeds the set value due to the fluid leakage. On the other hand, in the cutoff valve located downstream of the exposed part, the check valve closes and prevents the flow of fluid to the leakage part. Backflow is prevented, and as a result, only the fluid in the portion of the fluid circuit that extends between the two shutoff valves located upstream and downstream of the leak point leaks out.

Also, when using the shutoff valve described in claim 2, the valve body on the side that receives the differential pressure as the driving force for closing is normally held open in the same manner as described above, and the other valve body is held open in the same manner as described above. It is held open because it receives differential pressure as the driving force for opening. As a result, fluid circulation in the fluid circulation path is guaranteed during normal times. When a fluid leak occurs, in the shutoff valve located upstream of the leakage point, the valve body on the side that receives the differential pressure as the driving force for closing moves as described above, and the other side closes. In the shutoff valve located downstream, the valve element on the side that normally receives the differential pressure as the driving force for opening loses the set value as the driving force for closing due to the backflow of refrigerant due to leakage. In response to the above differential pressure, it closes against the biasing means. In other words, it acts as the aforementioned check valve. Moreover, as mentioned above, the two valve bodies differ only in that the flow direction of the fluid that acts to block them is opposite to each other, and the other functions are the same. Therefore, when interposed in the fluid circulation path, the two valve bodies The direction does not matter, as there is no problem even if one of the two valve bodies is located on the upstream side.

〔Effect of the invention〕

As is clear from the above, according to the present invention, when a fluid leak occurs, a shutoff valve that closes purely mechanically uses the differential pressure that inevitably increases as a driving force to prevent the fluid from leaking. Since it prevents this, reliability can be improved. As a result, the amount of refrigerant in the refrigerant piping is large, and leakage of such a large amount of refrigerant can lead to oxygen deficiency accidents.It is useful as a refrigerant piping device in cooling and heating equipment using heat pumps. It is now possible to provide a circulating fluid leakage prevention device.

Particularly, when a shutoff valve having the features described in claim 2 is used, workability is good because the shutoff valve can be incorporated into the fluid circulation path without considering its direction.

〔Example〕 ' Next, examples of the present invention will be shown.

As shown in Figure 2, the upper floors of buildings (top floors, rooftop floors, etc.)
An ice heat storage tank (1) and a condenser (2) that liquefies refrigerant gas using the stored cold heat of the ice heat storage tank (1) are installed, and etc.) is equipped with a hot water heat storage tank (3) and an evaporator (4) that liquefies the refrigerant liquid using the heat stored in the hot water heat storage tank (3). A cooling heat exchanger (5) that cools the conditioning air by gasifying the air and a heating heat exchanger (6) that heats the conditioning air by liquefying the refrigerant liquid are provided. A loop-type heat pipe (7) that naturally circulates refrigerant between the condenser (2) and the cooling heat exchanger (5), and the evaporator (4) and the heating heat exchanger (6). An air conditioning system is constructed by providing a loop-type heating heat pipe (8) that naturally circulates a refrigerant between the two.

The cooling heat exchanger (5) and the heating heat exchanger (6)
is incorporated as an indoor unit (9). Note that (10) is a liquid receiver, and (11) is an ice maker for heat storage, the exhaust heat of which is used as a heat source for the hot water heat storage tank (3).

Multiple locations of the refrigerant piping (12) for configuring the heat pipes (7) and (8), specifically, locations upstream of the branch point to each indoor unit (9), and each indoor unit (
A cutoff valve (13) that responds to bidirectional flow of refrigerant is installed at each location downstream of the confluence point from (9).

As shown in FIG.
3^), there are two valve bodies (13B) whose closing directions are opposite to each other.
), (13C) are provided, and these valve bodies (13B), (
Springs (130) and (13E) are provided as biasing means for biasing each of the valve bodies (13B) and (13C) in the opening direction.
The valve body (13B) on the side that receives the differential pressure in the closing direction when the refrigerant flows in the positive direction from one end to the other end
) is closed with a differential pressure that is greater than a set value, and a difference in pressure that is greater than a set value when the refrigerant flows through the valve box counterflow 1X (13F) in the opposite direction to the above. A second driving means for closing the other valve body (13C) using pressure is provided.

The two valve bodies (13B) and (13C) are the valve body (13B) on the side that receives differential pressure in the closing direction when the refrigerant in the flow path (13F) in the valve box flows in the forward direction.
(Hereinafter, this will be referred to as the first valve body, and the others will be referred to as the second valve body.

) is provided on the downstream side.

Moreover, the two valve bodies (13B) and (13C) are connected so as to move together.

The first driving means forms a pressure-receiving surface (13G) on the first valve body (13B) for receiving differential pressure as a driving force for closing operation, and uses the pressure-receiving surface (13G) when the differential pressure is a set value. In this case, the area is set so that the driving force is greater than the biasing force of the spring (130).

The second driving means differs from the first driving means only in that its target is the second valve body (13C).

Further, the pressure receiving surface (13G) of the first driving means and the second
The pressure receiving surface (13H) of the driving means is connected to the first valve body (13B), respectively.
), a second valve body (13C), and a diaphragm (14) attached to them.

In addition, the valve body (13A) has a flow path (13F) in the valve box.
When the fluid is flowing in the positive direction, the first valve body (13
The downstream side of B) is communicated with the outside and the first valve body (1
3B) to cause refrigerant leakage, and the downstream side of the second valve body (13C) in a state where fluid flows in the opposite direction through the flow path (13F) in the valve box. The second valve body (13C) is connected to the outside and tested.
A second test valve (150) is installed to generate a refrigerant leak that causes the valve to close.

Therefore, in the above-mentioned shutoff valve (13), the refrigerant pipe (12) is in a state where the forward direction is the refrigerant flow direction in the refrigerant pipe (12).
), it is biased to move in the opening direction, and when the differential pressure between the upstream and downstream sides exceeds the set value, it closes using the differential pressure greater than the set value as the driving force. The first valve body (13B) acts as the valve body of the one-way shutoff valve (13a), and the second valve body (13B) acts as the valve body of the check valve (13b).
13C) acts. On the other hand, in the opposite direction is the refrigerant pipe (12)
When the refrigerant is installed in the refrigerant pipe (12) with the refrigerant flowing in the direction shown in FIG. (13b)
The first valve body (13B) acts as a valve body.

In other words, when using the above cutoff valve (13), the one-way cutoff valve (13a) and the check valve (13)
b).

Therefore, according to the above embodiment, when refrigerant leakage occurs,
For example, if refrigerant leaks from a cooling heat pipe (7) at point A of the return piping to the condenser (2), the cutoff valve (13X) located upstream of point A in the return piping
and a cooling heat exchanger (5) connected downstream of the cutoff valve (13
) is located upstream of the branch connection point (B) of the shutoff valve (
13Y) and the one-way shutoff valve (13a) closes when the differential pressure exceeds the set value, while the shutoff valve (13Y) located downstream of point A in the return piping section and the feed piping A backflow occurs at the cutoff valve (13Y) located downstream of the branch connection point (B) in the section, and the respective check valves (13Y)
3b) moves closed. As a result, a piping section extending between the shutoff valves (13X) and (13X) located on both sides of point A, and a shutoff valve (13Y) located on both sides of the branch connection point (B),
(13Y) and the cooling heat exchanger (5)
Only the refrigerant present in the piping section for branching and merging therewith will leak out, and most of the refrigerant leakage is prevented. In short, the one-way cutoff valve (13a) of the cutoff valve (13X) located upstream of the refrigerant leakage part and the check valve (13b) of the cutoff valve (13Y) located downstream of the refrigerant leakage part close, causing the refrigerant leakage. This prevents refrigerant from flowing into the area.

[Another example]

Another example of the present invention will be shown below.

[1] In the above embodiment, a cutoff valve (13) is provided at the upstream side of the branch point and confluence point for each indoor unit (9).
However, in order to further reduce the amount of refrigerant leakage, the installation interval of the shutoff valves (13) should be made smaller. In addition, in order to reduce costs by reducing the number of shutoff valves (13),
The installation interval of the shutoff valves (13) is increased as much as possible, that is, within the range that can suppress the leakage amount to 1 or less without inducing an oxygen deficiency accident.

[2] In the above embodiment, as shown in FIG. When this occurs, a relief valve (16) is branched and connected to release the refrigerant in the refrigerant pipe (12) to the outside of the building. In this case, when a refrigerant leak occurs, the refrigerant pressure drops below the set value and the refrigerant is released outside the building from the relief valve (16), which opens, thereby preventing the refrigerant from leaking into the building. You can reduce the amount. Note that the relief valve (16) may be a solenoid valve that operates based on a refrigerant pressure detection sensor.
For example, as shown in Fig. 4, a valve body (19) is installed in a valve box (17) branch-connected to a refrigerant pipe (12) to block and hold a discharge port (18) using a refrigerant pressure higher than a set value as a driving force. and a biasing means using a spring (20) that opens the valve body (19) against the refrigerant pressure lower than the set value when the refrigerant pressure becomes lower than the set value, that is,
A mechanically operated one is preferable. (21) is the valve body (1
9) to the closed position.

[The three-piece shutoff valve (13) includes a first valve body (13B) and a second valve body (13C) as shown in FIGS. 5 and 6.
Only on itself is a pressure receiving surface (13
G), (13H) may be formed.

[4] As the shutoff valve (13), as shown in Fig. 5,
In a state where the fluid flows in the forward direction in the valve box-like flow path (13F), the first valve body (13B) may be located on the upstream side.

[5] In the above embodiment, the cutoff valve (13) has a structure in which the one-way cutoff valve (13a) and the check valve (13b) are integrated, but as the cutoff valve (13), As shown in Fig. 6, a one-way shutoff valve (13a) and a check valve (
13b) may be separate bodies connected by piping. In this case, a one-way shutoff valve (
The check valve (13b) is constructed by installing the same structure as the check valve (13a) in the opposite direction, thereby reducing the cost by making the valve a single specification.
13b) may of course be a simple check valve.

[6] In the above embodiment, the refrigerant pipe (12) was targeted, but the fluid circulation path (12) may also include a hot water pipe for heating that circulates hot water between the hot water generator and the indoor unit. and various hydraulic piping.

[7] Note that although reference numerals are written in the claims section for convenience of comparison with the drawings, the present invention is not limited to the structure of the accompanying drawings by such entry.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, with FIG. 1 being a sectional view and FIG. 2 being a refrigerant piping diagram. 3 to 6 show another embodiment of the present invention, in which FIG. 3 is a refrigerant piping diagram and FIGS. 4 to 6 are sectional views. (12)...Fluid circulation path, (13)...
・Shutoff valve, (13a)...One-way shutoff valve, (1
3b)...Check valve, (13A)...Valve box, (13B), (13C)...Valve body, (1
3F)... Valve box-like flow path.

Claims (1)

[Claims] 1. When the differential pressure between the upstream side and the downstream side exceeds a set value at each of a plurality of locations in the fluid circulation path (12), the fluid circulation path (12) is closed.
2) is equipped with a shutoff valve (13) that automatically shuts off the circuit, and the shutoff valve (13) is biased to move in the opening direction and is connected to the upstream side. When the differential pressure with the downstream side exceeds a set value, a one-way shutoff valve (13a) and a check valve (13b) close against the urging force using the differential pressure higher than the set value as a driving force. Circulating fluid leakage prevention device connected in close proximity to each other. 2. Two valve bodies (13B), (13
C), a biasing means for biasing the valve bodies (13B) and (13C) to move in the closing direction, and a flow path (13F) in the valve box.
a first driving means for closing one of the valve bodies (13B) and (13C) at a differential pressure equal to or higher than a set value when the fluid flows in the positive direction; and a flow path in the valve box. (13F) and a second driving means for closing the other valve body (13C) at a differential pressure equal to or higher than a set value among the differential pressures when fluid flows in the opposite direction.