CN204283511U - A kind of steam turbine switching mode low pressure oil motivation - Google Patents

Abstract

The utility model discloses a switch-type low-pressure oil motor for a steam turbine in the field of steam turbine control, which includes an oil inlet pipe, an oil return pipe, a flat valve, an oil cylinder and a piston that can slide horizontally along the oil cylinder. Connected between the oil inlet pipe and the oil return pipe; the flat valve includes a valve cover, an upper valve seat and a lower valve seat, an oil storage chamber is formed between the valve cover and the top surface of the upper valve seat, and the oil storage chamber Connected to the end of the oil inlet pipe, there is also a spring connecting the valve cover and the top surface of the upper valve seat in the oil storage chamber, the radial center of the upper valve seat is provided with a throttle hole, and the lower valve seat is coaxially located on the Below the upper valve seat, the radial center of the lower valve seat is provided with an oil inlet passage communicating with the throttle hole, and a plurality of circumferential through holes are arranged around the oil inlet passage to form an oil return passage, so Both the oil return channel and the oil return pipe communicate with the oil cylinder. Its technical effect is that it can quickly open and close steam turbine valves, has simple structure, low processing cost, and can cancel traditional safety oil pipelines.

Description

A switch-type low-pressure oil motor for a steam turbine

technical field

The utility model relates to a switch-type low-pressure oil motor for a steam turbine in the field of steam turbine control.

Background technique

Small and medium-sized power stations use steam turbines to drive steam valves (ie, steam turbine valves) through low-pressure oil motors, usually using double-sided oil-inlet control type low-pressure oil motors. This type of steam turbine is usually equipped with a head shaft pump. When all oil pumps are de-energized, the pressure of the head shaft pump is used to close the low-pressure oil motor, and then close the steam turbine valve (this action should be as fast as possible at this time) , to prevent the steam turbine from overspeeding, that is to say, the opening and closing of the low-pressure oil motor requires the power provided by the system to complete, and the oil consumption is large. In the case where the driving steam turbine is not equipped with a head shaft pump, the low-pressure oil motor with double-side oil inlet cannot accurately complete this task, while the control-type low-pressure oil motor with single-side oil inlet needs to be powered by the system to complete. Reducing the stroke of the piston rod of the control-type low-pressure oil motor until it closes can be completed quickly only by relying on the elastic force provided by the self-configured spring, which is more advantageous than the low-pressure oil motor with double-sided oil inlet. However, the currently used low-pressure oil motor with one-side oil inlet needs to be equipped with a spring-mounted control seat. Usually, the single-side oil motor and the control seat are separated and connected through a connecting mechanism. At the same time, the control seat needs to consider issues such as guidance, resulting in the overall structure Complicated and bulky.

Utility model content

The purpose of this utility model is to overcome the deficiencies of the prior art, and provide a switch-type low-pressure oil motor for steam turbines, which can quickly switch steam turbine valves, has a simple structure, low processing cost, and can cancel the traditional safety oil pipeline, which is beneficial to low-pressure motors. Optimal control of oil motor.

A technical solution to achieve the above object is: a switch-type low-pressure oil motor for a steam turbine, including an oil inlet pipe, an oil return pipe, a flat valve, an oil cylinder and a piston that can slide horizontally along the oil cylinder;

The oil inlet pipe and the oil return pipe are connected through two parallel shutdown solenoid valves;

The flat valve includes a bonnet, an upper valve seat and a lower valve seat arranged sequentially from top to bottom, the bonnet is sleeved on the radially outer side of the upper valve seat, the top surface of the upper valve seat is An oil storage cavity is formed between the valve covers, and the oil storage cavity communicates with the end of the oil inlet pipe; the oil storage cavity is provided with a plurality of springs connecting the top surface of the upper valve seat and the valve cover ;

The radial center of the upper valve seat is provided with a throttling hole;

The lower valve seat is coaxial with the upper valve seat, and the radial center of the lower valve seat is provided with an oil inlet channel communicating with the throttle hole, and the lower valve seat is also provided with an oil inlet passage surrounding the inlet valve seat. A plurality of circumferential through holes on the circumference of the oil passage, the plurality of circumferential through holes form an oil return passage;

The piston includes an inner piston plate that is horizontally slidable in the oil cylinder, an outer piston plate that is located between the oil cylinder and the turbine valve, and a piston rod, one end of which is connected to the The inner piston plate is fixed, and the other end runs through the radial center of the outer piston plate and is connected to the steam turbine valve; the outer piston plate is connected to the end wall of the oil cylinder through a compression spring;

The inner piston plate divides the oil cylinder into an inner cavity near the steam turbine valve side and an outer cavity away from the steam turbine valve side in the horizontal direction, and the oil inlet passage communicates with the inner cavity of the oil cylinder, Both the oil return channel and the oil return pipe communicate with the outer cavity of the oil cylinder.

Further, the oil motor also includes a test solenoid valve, the test solenoid valve communicates with the inner chamber of the oil cylinder through a first test pipeline, and the test solenoid valve communicates with the oil return pipe through a second test pipeline. Test line connection.

Further, a limiting plate parallel to the inner piston plate is provided in the inner cavity of the oil cylinder.

Further, the outer cavity of the oil cylinder is provided with an oil return flange.

The technical scheme of a switch-type low-pressure oil motor for steam turbines of the present invention is adopted, that is, the oil inlet pipe and the oil return pipe are connected by two parallel stop solenoid valves, and a flat valve connected to the oil inlet pipe is provided. An annular oil return passage located on the radially outer side of the oil inlet passage, and a technical scheme in which both the oil return passage and the oil return pipe are connected to the outer cavity of the oil cylinder. Its technical effect is: it can quickly open and close steam turbine valves, has simple structure, low processing cost, and can cancel traditional safety oil pipelines, which is beneficial to the optimal control of low-pressure oil motors.

Description of drawings

Fig. 1 is a schematic front view of the appearance of a switch-type low-pressure oil motor for a steam turbine of the present invention.

Fig. 2 is a schematic top view of a switch-type low-pressure oil motor for a steam turbine of the present invention.

Fig. 3 is a schematic diagram of the internal interface of a switch-type low-pressure oil motor for a steam turbine of the present invention.

Detailed ways

Please refer to Fig. 1 to Fig. 3, in order to better understand the technical solution of the present utility model, the inventor of the utility model will describe in detail below through specific embodiments in conjunction with the accompanying drawings:

Please refer to Fig. 1 to Fig. 3, a switch-type low-pressure oil motor for a steam turbine of the present invention is opened under the effect of hydraulic pressure and closed under the effect of spring force.

A switch-type low-pressure oil motor of the present utility model includes a cover body 100, a housing 200, a plate valve 3, an oil cylinder 4, a piston 5, a first stop solenoid valve 61, a second stop solenoid valve 62, a test solenoid valve 7, and a valve A switch box 300 and a terminal box 400 . And the oil inlet pipe 1 and the oil return pipe 2 located in the cover body 100 .

The first stop solenoid valve 61 and the second stop solenoid valve 62 are connected in parallel between the oil inlet pipe 1 and the oil return pipe 2 .

The plate valve 3 includes an upper valve seat 31, a lower valve seat 32, a valve cover 34 and a plurality of springs 35. The lower valve seat 32 is annular, coaxial with the upper valve seat 31, and located below the upper valve seat 31. The valve cover 34 is sleeved on the radially outer side of the upper valve seat 31 and forms an oil storage chamber 36 with the top surface of the upper valve seat 31 . A plurality of springs 35 are all located in the oil storage chamber 36 and are connected to the top surface of the upper valve seat 31 and the valve cover 34 . The oil storage chamber 36 communicates with the end of the oil inlet pipe 1 . The center of the upper valve seat 31 is provided with an orifice 311 . The function of the orifice 311 is to control the oil intake of the oil motor, and make the pressure oil fill the oil storage chamber 36 during the startup process of the oil motor. The radial center of the lower valve seat 32 has a central hole, forming an oil inlet passage 37 communicated with the throttle hole 311 . The lower valve seat 32 also has a circle of circumferential through holes surrounding the circumference of the oil inlet passage 37 to form an annular oil return passage 38 . The purpose of this design is to increase the caliber of the oil return channel 38, improve the oil return capacity of the switch-type low-pressure oil motor for the steam turbine, accelerate the pressure oil into the oil return channel 38, and ensure that the switch-type low-pressure oil for a steam turbine of the present invention Motive quick off function.

Below the plate valve 3 are an oil cylinder 4 and a piston 5 . The piston 5 includes an inner piston plate 51 that can slide horizontally in the oil cylinder 4, an outer piston plate 52 between the oil cylinder 4 and the steam turbine valve, and one end is fixed to the radial center of the inner piston plate 51, and the other end is sequentially fixed. The radial center of the steam turbine side end wall penetrating through the oil cylinder 4 and the radial center of the outer piston plate 52 are connected to the steam turbine valve and are used to open and close the piston rod 53 of the steam turbine valve. The inner piston plate 51 divides the cylinder 4 into two chambers. The chamber close to the valve of the steam turbine is the inner chamber 41 , and the chamber far away from the valve of the steam turbine is the outer chamber 42 . The inner cavity 41 is provided with a limiting plate 54 parallel to the inner piston plate 51 to limit the sliding of the inner piston plate 51 . At the same time, the end wall of the oil cylinder 4 on the side of the steam turbine valve is connected with the outer piston plate 52 through a compression spring 55 .

At the same time, both the oil return channel 38 and the oil return pipe 2 communicate with the outer chamber 42 of the oil cylinder 4 . The outer cavity 42 of the oil cylinder 4 is provided with an oil return flange 310, which sends the oil return to the external system to ensure the quick-off function of a switch-type low-pressure oil motor for a steam turbine of the present invention.

The pressure oil in the oil storage chamber 36 enters the inner cavity 41 of the oil cylinder 4 through the orifice 311 and the oil inlet passage 37 . At the same time, the pressure of the pressure oil in the oil storage chamber 36 and the spring force of the spring 35 in the oil storage chamber 36 act together to make the bottom surface of the upper valve seat 31 close to the top surface of the lower valve seat 32, and the oil return passage 38 is closed. . After the pressure oil enters the inner cavity 41 of the oil cylinder 4, the hydraulic pressure of the pressure oil makes the piston 5 overcome the elastic force of the compression spring 55 and the steam pressure, etc., so that the inner piston plate 51 moves away from the steam turbine valve, and the outer piston plate 52 and the inner piston plate 52 The piston plate 51 moves in the same direction, the compression spring 55 is compressed, and the steam turbine valve is opened.

The oil inlet pipe 1 and the oil return pipe 2 are connected by the first stop solenoid valve 61 and the second stop solenoid valve 62 connected in parallel. When any one of the first stop solenoid valve 61 and the second stop solenoid valve 62 is opened, the oil inlet pipe 1 The pressure oil inside enters the oil return pipe 2 directly through the first stop solenoid valve 61 or the second stop solenoid valve 62. After the oil pressure in the oil storage chamber 36 is released, the oil pressure at the bottom of the upper valve seat 31 overcomes the spring force of the spring 35, The upper valve seat 31 is lifted, and the oil return passage 38 is opened. The pressure oil in the inner cavity 41 of the oil cylinder 4 enters the oil return passage 38, and as the pressure oil in the inner cavity 41 of the oil cylinder 4 decreases, the inner piston plate 51, the outer piston plate 52, the piston rod 53 and the compression spring 55 of the piston 5 Recovery, the valve of the steam turbine is closed, and a switch type low-pressure oil motor for a steam turbine of the present invention is closed.

Through the above-mentioned technical means, the shut-off of the steam turbine depends on the two shutdown electromagnetic valves as the guide, and the oil in the oil inlet passage 37 is put into the oil return passage 38 through the flat valve 3, and the switch type low-pressure oil motor for the steam turbine is closed by the elastic force of the compression spring 55. Steam turbine valves. The switch-type low-pressure oil motor for steam turbine of the utility model adopts fail-safe control principle, adopts redundant shutdown solenoid valve, shuts down the oil motor when the shutdown solenoid valve loses power, cancels the traditional safety oil pipeline, and lays the foundation for the optimization of the control system.

The test solenoid valve 7 communicates with the inner cavity 41 of the oil cylinder 4 through a first test pipeline 71 , and the test solenoid valve 7 communicates with the oil return pipe 2 through a second test pipeline 72 . Test electromagnetic valve 7 is responsible for piston rod 53 activity tests.

The oil inlet pipe 1 , the oil return pipe 2 , the first test pipeline 71 , and the second test pipeline 72 are all internal oil pipes, which are placed in the cover body 100 and the housing 200 .

Those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the utility model, rather than as a limitation to the utility model, as long as within the spirit of the utility model, the above-mentioned The changes and modifications of the embodiments will all fall within the scope of the claims of the present utility model.

Claims (4)

1. A switch-type low-pressure oil motor for a steam turbine comprises an oil inlet pipe, an oil return pipe, a flat valve, an oil cylinder and a piston that can slide horizontally along the oil cylinder; it is characterized in that: The oil inlet pipe and the oil return pipe are connected through two parallel shutdown solenoid valves; The flat valve includes a bonnet, an upper valve seat and a lower valve seat arranged sequentially from top to bottom, the bonnet is sleeved on the radially outer side of the upper valve seat, the top surface of the upper valve seat is An oil storage cavity is formed between the valve covers, and the oil storage cavity communicates with the end of the oil inlet pipe; the oil storage cavity is provided with a plurality of springs connecting the top surface of the upper valve seat and the valve cover ; The radial center of the upper valve seat is provided with a throttling hole; The lower valve seat is coaxial with the upper valve seat, and the radial center of the lower valve seat is provided with an oil inlet channel communicating with the throttle hole, and the lower valve seat is also provided with an oil inlet passage surrounding the inlet valve seat. A plurality of circumferential through holes on the circumference of the oil passage, the plurality of circumferential through holes form an oil return passage; The piston includes an inner piston plate that is horizontally slidable in the oil cylinder, an outer piston plate that is located between the oil cylinder and the turbine valve, and a piston rod, one end of which is connected to the The inner piston plate is fixed, and the other end runs through the radial center of the outer piston plate and is connected to the steam turbine valve; the outer piston plate is connected to the end wall of the oil cylinder through a compression spring; The inner piston plate divides the oil cylinder into an inner cavity near the steam turbine valve side and an outer cavity away from the steam turbine valve side in the horizontal direction, and the oil inlet passage communicates with the inner cavity of the oil cylinder, Both the oil return channel and the oil return pipe communicate with the outer cavity of the oil cylinder. 2. A switch-type low-pressure oil motor for a steam turbine according to claim 1, characterized in that: the oil motor also includes a test solenoid valve, and the test solenoid valve and the inner chamber of the oil cylinder pass through a first The test pipeline is connected, and the test electromagnetic valve is connected with the oil return pipe through the second test pipeline. 3. The switch-type low-pressure oil motor for a steam turbine according to claim 1, wherein a limit plate parallel to the inner piston plate is provided in the inner cavity of the oil cylinder. 4. A switch-type low-pressure oil motor for a steam turbine according to claim 1, characterized in that: the outer cavity of the oil cylinder is provided with an oil return flange.