KR20220131086A - Turbine bypass valve - Google Patents

Abstract

The present invention relates to a turbine bypass valve, wherein a first mesh pipe (205) is installed to firstly offset steam of a high temperature and a high pressure within a steam introduction pipe formed at a valve body (201) unit. In addition, the present invention further comprises: a cage pipe (206) which is composed of a two-staged layer mounted within the valve body (201); and a sheet ring (207) which performs sealing with a plug (300) which is in connection coupling state with a stem (301). In a state of being individually mounted in a horizontal surface reference direction from the inside of the valve, a second mesh pipe (208) is inserted between diffuser pipes (209) in a cylindrical shape in which a plurality of steam flow path holes are perforated and formed to complete a main valve assembly unit. Therefore, the present invention relates to a bypass valve, which may provide a method for changing the pressure of steam, supplied in a high-temperature and high-pressure state, to an adequate figure.

Description

Turbine bypass valve {Turbine bypass valve}

The present invention relates to a bypass valve of a steam turbine applied to a power plant, which is a means for continuing the operation of a boiler when the steam turbine is stopped due to its own emergency state. It relates to a valve that allows steam to be discharged quickly through a bypass valve.

Therefore, high temperature in the steam turbine bypass valve. When the environment in which high-pressure steam is introduced and passed is created, first of all, the trim accessories installed inside the valve are exposed to the pressure stress effect by the high-temperature steam and high-pressure steam passing at high speed. As a gradual creak occurred in the surface recesses of major parts, the surface layer was damaged or damaged along with the surrounding fixing devices in many cases. The cause of the frequent occurrence of accidents was also provided,

In addition, in order to prevent the above problems, a lot of effort and separate research have been required in the industry, and as a method to solve such problems, the high-pressure, high-temperature steam flowing into and flowing into the bypass valve is reduced in temperature, It relates to a steam turbine bypass valve configured to safely discharge steam in a reduced pressure state.

In general, turbine valves are divided into several types according to the purpose. During emergency operation of a power plant, the generated high-temperature and high-pressure steam is discharged through the bypass valve without introducing or passing through the turbine, so that the boiler can be operated independently. It is pointed out that the provision of functions required in emergency situations is a matter to be resolved first.

More specifically, in the steam turbine line, the steam of 500 ~ 600 ℃ from the boiler is transferred to the steam turbine through the valve device, and the steam after achieving the purpose in the turbine is restored to water in the condenser and , the feed water circulates in the order that it is supplied back to the boiler by the pump.

That is, the high-temperature, high-pressure steam generated by the steam generator is supplied to the place where the quick shut-off valve and the control valve are arranged, which is assigned to the steam line, and the control valve supplies steam through the steam line only when the quick shut-off valve is opened. The starting force is performed for the purpose of controlling the valve, and the quick shutoff valve responds quickly and automatically to shut off the fluid in case an operation failure occurs.

However, in the valve subjected to the high temperature and high pressure of the steam as described above, the steam is further expanded due to the pressure of the steam saturated between the stem and the bonnet installed inside the valve, resulting in weakening the valve function in part, At the same time, as the steam pressure supplied along the turbine line increases, the temperature of the blade of the turbine rises beyond the allowable value, and an accident due to micro-contact between the blade and the stopper occurs, resulting in an emergency operation stop. cases will occur.

At this time, as a means for continuing the operation of the boiler, the steam flowing into the steam turbine flows out of the high-pressure steam through the bypass valve to prevent the start line from being stopped. By bypassing the boiler through the valve instead of directly passing it through the turbine, the boiler can be continuously operated in a given environment by the recirculation process of the fluid regardless of the turbine condition.

In the conventional bypass valve accompanying the action process as described above, looking at the configuration of FIG. 1 , the plug 3 connected with the stem 5 in the center of the valve body 1 in the vertical axis direction, formed as a long space. ) and a seat ring (4), and a cage tube (6) with a hole through which the steam introduced according to the closing action of the plug and the seat ring passes through, and the steam introduced from the cage tube A diffuser 7 is installed to allow it to flow out in a temporary confinement state, and a plurality of cooling sprayers 11 for cooling the fluid vapor are configured in the vapor outlet discharge pipe 9 in which the diffuser 7 is accommodated.

In the assembled valve, the stem 5 operates in the upper and lower operation sections, and the plug 3 connected to the stem as such is in close contact with the seat ring 6 having sealing force. Closing and opening are made, and high-pressure steam penetrates and passes between the perforated holes 8 of the cage 3, and passes through the fine holes 8 of the diffuser 7 to slow the flow of steam. After the sea flow, the steam is bypassed through the outlet 11 and is configured to escape.

The conventional valve as described above proposes a method of weakening the temperature more or reducing the vapor pressure of the high pressure state above all when the main steam in the high temperature and high pressure state is supplied, but rather the stem inserted into the valve bonnet part Since the adhesion between the seal and the packing seal was insufficient, there were many cases where steam leaked out between the gaps in the assembled state.

This is also the cause of selecting and using a material that is vulnerable to high temperature and high pressure steam, but above all, because the valve itself operates in the assembled state in the axial direction, due to the characteristics of the high pressure steam injected into the valve, the high temperature that entered the space above the valve It is judged that steam leakage increases and escapes between the stem and packing seal of the valve by the action of further diffusion of the steam by its own expansion force. Due to the use, the vapor outlet holes were eroded or worn due to the flow rate pressure and the development of fluid oxidation.

The present invention has been devised to improve the above problems, and first, a first mesh pipe that acts to first offset high-temperature and high-pressure steam inside the steam inlet pipe formed in the valve body part is installed and fixed, and then , a cage tube composed of two layers installed inside the valve body, a plug connected to a separate stem, and a seat ring having a plug and sealing action force are installed in the horizontal plane reference direction from the inside of the valve, respectively, and the steam passage hole is The main valve assembly is completed by inserting a second mesh pipe between the diffuser duct of a cylindrical shape in a state in which a plurality of holes are formed.

In addition, a method to change the steam pressure supplied at high temperature and high pressure to a more appropriate value by installing several cooling sprayers at the position around the discharge pipe where the high-temperature steam introduced through the valve is discharged through the external transfer pipe It relates to a bypass valve intended to provide

As a method for achieving the above object, the bypass valve device has a body and a bonnet, and a first mesh tube is installed at the front end of the inlet tube,

In the center of the valve, a plug coupled to the sleeve-type cage tube and the stem, and a seat ring having adhesion to the main portion of the plug, and a second mesh tube are fixedly arranged between the space of the seat ring and the diffuser duct, In the valve stem part, the stem and the packing seal are inserted and operated by using the bonnet as a mother body,

Among the valve accessories provided above, the first and second mesh pipes may be cast or made of a stainless wire mesh structure, and resistance to high temperature and high pressure steam is obtained by selecting a material that can withstand the pressure of the flowing steam. Configure it to be able to

In addition, the cage tube structure provided in a cylindrical shape through which the vapor that has passed through the mesh tube enters and passes to the next stage is composed of a circular two-stage multi-layered main part, and the fluid entry and passage holes are provided around the inner and outer surfaces. It is configured to be used as a means to further drop the heat and pressure of the incoming steam.

In addition, a seat ring and a plug acting as a sealing function are assembled inside the cage tube space, and the second mesh tube is combined between the seat ring and the diffuser tube placed in the next assembly process sequence.

The plurality of passage holes formed around the wall of the diffuser tube are configured for the purpose of supplying the hot air pressure to the steam having high temperature and high pressure by slightly lowering the pressure.

The bypass valve according to the present invention configured as described above is a valve used as a means to protect a power plant turbine in an emergency, and the high temperature and high pressure flow provided from the boiler in a high temperature and high pressure state by improving and assembling the parts installed in the valve. It relates to an invention for preventing damage to a valve in advance by suppressing the phenomenon of steam being discharged at high pressure and high temperature by reducing the temperature and pressure of the steam itself.

1 is a cross-sectional side view of a conventional bypass valve.
Figure 2 is a bottom view of the outlet of the conventional bypass valve.
Figure 3 is a side cross-sectional view showing an open state of the present invention turbine bypass valve.
4 is a side cross-sectional view showing a state in which the present invention turbine bypass valve is closed.
5 is a front view of the bypass valve of the present invention.

The present invention will be described with reference to the accompanying drawings with respect to the turbine bypass valve as described above by way of example.

The embodiment of the present invention is not considered to be limited in its practicable state, but is only intended to embody the present invention, and those skilled in the art who understand the spirit of the present invention may use other embodiments included within the scope of the same technical spirit. to be proposed, but this will also be included in the technical spirit of the present invention.

As previously described, the conventional valve of FIG. 1 is a valve that is fixedly installed and used in the upper and lower axial directions. The cage tube 3 and the seat ring 4 are combined, and the diffuser tube 7 connected together with the seat ring 4 is installed.

In the inside of the cage tube (3), a long hole plug (5) operated upwards and downwards related to the vapor sealing action is device-configured together with the stem (6), and an inlet ( 9) and the outlet 10 are formed at right angles to the valve body 1, respectively.

The cage pipe 3 is used as a means for lowering the pressure of the high-temperature steam flowing in from the steam inlet 9, and the diffuser pipe 7 has also been installed and used for the same purpose.

However, the working effect only provided a negligible effect, and on the contrary, the failure rate of the valve itself increased, resulting in bad rotational disturbance in the turbine blade.

In the present invention, the cage tube of the present invention is composed of a double tube as a partial multi-layer structure, and the present invention is not limited to such dimensions and shapes, and includes examples of deformations having shapes and dimensions showing the same or similar functions. Those who belong to it will easily understand.

3 is a detailed cross-sectional view of the side of the bypass valve of the present invention, the steam inlet 203 and the outlet 204 are formed on the rear surface of the valve body 201 assembled in a horizontal shape, the inlet 203, the tip end In the inner tube, the first mesh tube 205, which acts to indirectly offset the flow of high-pressure steam introduced primarily, is disposed in the tip portion, and the steam flowing through the inside of the disposed tip tube is continuously blocked at a pressure a cage tube 206 formed in a tubular shape acting to be passed through, a seat ring 207 connected and coupled together with the cage tube 206, and a second formed of a hole 306 perforated with a projected mirror surface area An assembly including a diffuser tube 209 together with a mesh tube 208 is configured.

In addition, in the empty space in which the cage tube 206 and the seat ring 207 are assembled, the plug 300, which functions as a sealing in connection with the seat ring 207, operates left and right according to the piston principle. After completion of fastening to the stem 301, the cage tube 206 is accommodated in the inner space, but the accommodated plug 300 and the stem 301 are installed between the inside and the outside of the bonnet 202. 302) As the stem rod is inserted into the hole, the assembly is completed.

In addition, in the plug 300 , the accessory configuration installed between the plug 300 and the stem 301 includes an elastic spring 304 around the exterior of the variable plug 303 integrally formed with the stem 301 . The fixing plate 305 is fixed by tightening the bolt to the assembled part in the inserted state, which provides a method of relieving the shock relief between the stem 301 and the plug 300 .

With respect to the bypass valve configured as described above, when explaining the action on the main device components, first, in the cage tube 206, it is composed of a single-stage straight tubular structure, and acts based on a predetermined interval. In the cage pipe 206, which is made to be completed in a double-layered shape by separately preparing a double-layered exterior made with a slightly wider diameter at the location of the single-layered tube in the main tube where the structure is formed, flow on the surface of the double-layered double-layered tube Provided with a plurality of outlet holes 306 through which steam can be introduced and passed, the pressure and high temperature temperature of the steam flowing in and passing can be more offset in the secondary stage.

Therefore, the resistance range for the high-pressure steam flowing into the first mesh pipe 205 and the second mesh pipe 208 shows a temperature reduction and decompression effect comparable to the resistance range of the cage pipe 206, and also The shape of the hole 306 formed in the first mesh pipe 205 and the second mesh pipe 208 is made up of various types of structures, and is made by metal forming or specially processed metal wire (wire). It can also be used using a mesh network formed by

On the other hand, the configuration of the diffuser tube 209 is configured in a shape in which one end of the tube is blocked in a curved shape, and high-pressure steam is discharged in a state where more holes 306 are perforated, and also the high-pressure The atmospheric saturation state, that is, the saturation pressure state, sometimes occurs due to the situation in which the steam of the A bypass valve capable of discharging steam in a state in which high temperature and high pressure are further reduced by using the cooling sprayer 308 that acts is provided.

201.....Body 302.....Packing Seal
202.....Bonnet 303.....Variable Plug
203.....Inlet 304.....Spring
204.....Outlet 305.....Fixed plate
205.....First mesh pipe 306.....Hole
(mesh duct)
206.....Cage tube 307....Cooling sprayer
207.....Seating ring 308.....Coolant inlet
208...Second mesh pipe 309...Piping
209.....Diffuser tube
(diffuser duct)
300.....plug
301.....Stem

Claims (1)

A convex tubular, first mesh pipe 204 is formed in the front end of the inlet 203, in which the valve body 201 and the bonnet 202 are assembled in the left and right horizontal directions, and a circular cage pipe 206 installed in the center of the valve. The seat ring 207, the second mesh tube 208, and the diffuser tube 209 are continuously fixed on the side, and the plug 300 and the assembled stem 301 are inserted into the cage tube 206, and the bonnet A valve coupled to (202), the valve comprising:
The first and second mesh tubes 205 and 208 are perforated in the tubular curved surface area from which radial holes 306 protrude,
The cage tube 206 has a hole 306 through which superheated steam passes, around the inner and outer surfaces of which a certain portion is composed of a circular two-stage multi-layer space,
The diffuser tube 209 for dispersing and discharging the steam introduced in the saturated state due to the increased density of the superheated steam, and a cooling sub-weapon capable of discharging the steam concentrated in the overheated saturated state by further depressurizing and reducing the temperature. Turbine bypass valve, characterized in that.

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