JPH0577921B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a steam temperature reduction valve used for reducing the temperature of superheated steam.

Generally, steam is generated as relatively high-pressure steam in a steam generation source such as a boiler, and is used after being reduced in pressure at the inlet side of various steam-using equipment depending on the purpose of use of the steam-using equipment. Due to its nature, high-pressure steam becomes superheated steam when its pressure is reduced, making it difficult to adjust the amount of heat transferred in steam-using equipment and making uniform heat transfer impossible.

<Prior art> Generally, the temperature of superheated steam is reduced by this type of temperature reduction device by injecting cooling water into the flow of superheated steam and absorbing the thermal energy of the superheated steam by the latent heat of the cooling water. .

Therefore, conventionally, as shown in FIG. 2, a device has been used in which pressurized spray water is directly sprayed onto superheated steam from a spray nozzle 52 through a spray water pipe 50 to reduce the temperature to a predetermined temperature. This is done by arranging the spray nozzle 52 on the upstream side in the superheated steam passage 54 and providing a temperature detector 56 on the downstream side, so that the superheated steam reaches a predetermined temperature in response to the temperature detected by the temperature detector 56. Adjust the opening degree of the control valve 58. In other words, the deviation between the set value of the steam temperature and the detected temperature is calculated, the amount of spray from the spray nozzle 52 is determined by the PID controller so as to reduce this deviation to zero, and the control valve 58 is operated to adjust the steam temperature. It is something to control.

<Problems to be Solved by the Present Invention> The above-mentioned device includes a temperature detector that detects the reduced temperature of steam, a control valve that adjusts the opening degree according to the detected temperature, and the temperature sensor and the control valve. In addition, the temperature sensor had to be installed separately in the steam passage, and the control valve had to be installed in the spray water passage, respectively, resulting in increased equipment and construction costs. In addition, the control became complicated, and determining the PID constant was difficult and required experience.

The technical problem of the present invention is to reduce the temperature of superheated steam efficiently with a simple and inexpensive device without requiring complicated control.

<Means for Solving the Problems> The technical means of the present invention taken to solve the above-mentioned technical problems includes a spray valve port for atomizing spray water in a valve casing having an inlet and an outlet. , a valve body that forms a conical cylindrical part that temporarily expands toward the outlet side, is always biased toward the inlet side by a biasing spring within the cylindrical part, and opens the valve by changing the degree of opening according to the flow rate of steam flowing inside the valve casing. A spray valve element is attached to the valve element, and the spray valve element opens and closes the spray valve port in accordance with the displacement of the valve element.

<Operation> When steam is not passing through the valve casing,
The valve body maintains the closed state at the small diameter portion of the conical cylindrical portion by a biasing spring. At this time, the spray valve body provided integrally with the valve body also closes the spray valve port, thereby stopping the spray water from entering.

When the steam fluid flows, the fluid moves the valve element toward the outlet side against the biasing force of the biasing spring. When the valve body moves, the spray valve body also opens the spray valve port, spray water is sprayed inside the casing, and the temperature of the superheated steam is reduced. As the amount of steam passing through increases, the flow resistance increases and the valve body is displaced toward the outlet side, but at the same time, the distance between the inner wall of the conical cylinder and the valve body increases, and the opening area also increases, and the flow resistance increases accordingly. The valve body becomes smaller and stops at a position balanced with the biasing spring. Therefore, the opening degree of the valve is determined according to the amount of steam passing through, and the opening degree (displacement) of the spray valve port is also determined accordingly.

Strictly speaking, the specific heat differs depending on the pressure of the steam, so even if the steam flow rate is the same, the amount of water sprayed must also be changed.However, in reality, depending on external conditions such as heat radiation, the specific heat can be considered to be almost the same. Therefore, it is only necessary to adjust the amount according to the amount of steam passing through regardless of the pressure.

<Specific effects> The present invention produces the following unique effects.

Since the amount of spray water can be automatically adjusted using a mechanical configuration, there is no need for expensive pressure detectors, control valves, or connecting wires that connect the two, and the steam temperature can be reduced at low cost with a simplified device. be able to. Furthermore, the set temperature of the passing steam can be adjusted by adjusting the adjustment rod.

<Example> An example showing a specific example of the above technical means will be described (see FIG. 1).

The parts 2, 4 and 6 form a valve casing having an inlet 8 and an outlet 10. The member 4 forms a conical cylindrical portion 12 which flares out slightly in the direction of the outlet. First bearing 14
A fluid passage hole 16 is provided, a bearing 19 is formed in the center, and the bearing 19 is sandwiched and fixed between the members 2 and 4.
A valve body 18 having a diameter large enough to substantially close the small diameter portion of the conical cylindrical portion 12 is disposed within the conical cylindrical member 12 so as to be biased toward the inlet side by a biasing spring 17, and the valve shaft 20 passes through the bearing 19, and the outlet side thereof is locked with a snap ring 24 provided with a bimetal 22 on a disk that expands at high temperature.

A second bearing 26 and a valve seat support member 28 are sandwiched and fixed between the member 4 and the member 6. Valve seat support member 28
The spray pipe 3 introduced from the outside into the member 6 is
0 end is connected, and the spray valve port 36 is connected to the outlet side.
Attach the valve seat 38 having a

On the other hand, a spray valve body 32 is attached to the inlet side of the valve body 18, and the spray valve port 36 is opened.
The valve stem 34 is guided by a second bearing 26. Second
The bearing 26 and the valve seat support member 28 are also provided with fluid passage holes 40 and 42, respectively.

The action is as follows. FIG. 1 shows a state in which the spray valve port is completely closed, and at this time, there is a slight gap 44 between the valve body 18 and the inner base of the cylindrical portion 12. This is a measure to prevent the valve body 18 from initially becoming difficult to open against the biasing spring 17 when the flow rate is small.

When the superheated steam fluid flows, the flow resistance causes the valve body 18 to move toward the outlet side against the valve 17,
Outlet 1 from the opened valve body and the inner wall surface of the cylindrical portion 12
0, and the spray valve port 36 also opens in accordance with the displacement of the valve body at this time, spraying water and reducing the temperature.

When the steam flow further increases, the flow resistance causes the valve body 18 to be further displaced toward the outlet side, but at the same time, the passage area between the inner wall surfaces of the cylindrical portion also increases and the flow resistance becomes smaller, so that the flow resistance is reduced by the biasing spring. The valve body stops at the point where it is balanced. That is, the displacement of the valve body is determined according to the steam flow rate, the opening degree of the spray valve port is also determined, and the amount of spray water is also determined accordingly.

Normally, when the spray valve port 36 is closed, the steam that has passed through the gap 44 between the valve body 18 and the inner wall of the cylindrical part 12 has almost no effect on the secondary side due to heat radiation, but if some cause If a large amount of steam flows and the temperature on the secondary side rises too much, the bimetal 22 expands and pulls the valve shaft 20, opening the spray valve port 36 and reducing the temperature. That is, this bimetal only operates in abnormal situations.

As mentioned above, the specific heat of steam differs depending on the pressure, but when handled in a process, it can be considered that they are almost the same. Therefore, if the degree of heating (temperature rise from saturation temperature) is the same at any pressure, a common spray can be used. The valve diameter may be used, but if the degree of superheating is different, it is better to change the valve seat 38 and change the valve diameter.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a steam attemperation valve according to the present invention, and FIG. 2 is a conventional steam attemperation device. 8... Inlet, 10... Outlet, 12... Conical cylindrical portion, 18... Valve body, 22... Bimental, 3
2...Spray valve body, 36...Spray valve port.

Claims (1)

[Claims] 1 In a valve casing having an inlet and an outlet, a spray valve port for spraying water and a conical cylindrical part that temporarily expands toward the outlet side are formed, and a biasing spring inside the cylindrical part is constantly biased toward the inlet side. A valve element that opens the valve by changing the degree of opening according to the flow rate of steam flowing inside the valve casing is arranged, and a spray valve element is attached to this valve element, and this spray valve element sprays water according to the displacement of the valve element. A steam detemperature valve with a valve opening that opens and closes.