Pneumatic magnetic cut-off throttle device for security of steam turbine compressor unit

Abstract

The present invention relates to a pneumatic magnetic cut-off throttle device for the security of a steam turbine compressor unit. An intermediate support is installed on the upper part of the throttle housing of the pneumatic cut-off throttle. A hydraulic slide valve and a pneumatic piston are installed in the throttle housing. A gear-rack transmission mechanism is installed in the intermediate support. An air safety valve is installed on the side of the throttle housing, and the air safety valve is communicated with the upper chamber or the lower chamber of the pneumatic piston. An electro-hydraulic mechanism is installed on the upper part of the intermediate support. The electro-hydraulic mechanism has a magnetic force actuator cylinder. The upper and lower chambers of the piston rod in the magnetic force actuator cylinder are respectively connected to a pressure oil pump through a two-position four-way solenoid valve. The lower end of the piston rod passes through one side rack in the gear-rack transmission mechanism and is fixedly connected to the upper end of the pneumatic piston. This rack is linked to the other side rack in the gear-rack transmission mechanism through a gear. The other side rack is fixedly connected to the upper end of the hydraulic slide valve. The inner cavity of the hydraulic slide valve is connected to the power oil inlet, the outer cavity is connected to the power oil outlet, and an oil return port is arranged below the inner cavity of the hydraulic slide valve.

Description

Technical Field

[0001] The present invention relates to the security of a steam turbine compressor unit, and particularly to a throttle device for a steam turbine compressor. Background Art

[0002] The press needs to be provided with a protection shutdown function for high exhaust pressure (back pressure), generally an overpressure power-off and quick shutdown protection. There are two forms of overpressure power-off and quick shutdown protection: one is to measure the exhaust port pressure through a sensor and judge through a controller. When the pressure exceeds the set pressure, the power supply of the prime mover is cut off to achieve shutdown; the other is through a pressure relay. When the pressure exceeds the set pressure, the power supply of the prime mover is cut off to achieve shutdown. However, the conventional protection shutdown technology for high exhaust pressure is based on electrical components and equipment to achieve the function, and the reliability of the protection action needs to rely on the reliability of the electrical components and electrical equipment.

[0003] Therefore, a "pneumatic break throttle" device has been invented, which realizes the back pressure protection of the compressor through the principles of pure hydraulic, pneumatic, and mechanical transmission. The structural composition principle of this device is shown in Figure 1 .

[0004] When the exhaust pressure of the compressor exceeds the rated pressure and rises to a certain overpressure limit value due to some reason, the compressed air introduced from the exhaust port enters the upper chamber of the pneumatic break throttle piston. The piston quickly moves downward against the spring force, and then drives the slide valve downward through the gear and rack, thereby cutting off the high-pressure oil leading to the main steam valve and closing the emergency stop of the steam turbine main steam valve. The high-pressure oil under the slide valve flows into the oil tank from the bottom oil return port.

[0005] The "pneumatic break throttle" device makes up for the defects of the conventional "overpressure power-off and quick shutdown protection" device and improves the reliability of the back pressure protection of the compressor unit. However, it itself also has the hidden danger of mechanical jamming and failure, and the use of two sets of devices occupies more dimensional space. Therefore, it is necessary to design a new type of pneumatic magnetic break throttle device. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to propose a pneumatic magnetic break throttle device for the security of a steam turbine compressor unit with an integrated structure, which can not only realize the exhaust overpressure protection shutdown function without relying on the reliability of electrical equipment, but also retain the conventional overpressure power-off and quick shutdown protection shutdown function; at the same time, eliminate the hidden danger of mechanical jamming and failure of the "pneumatic break throttle" device, and organically integrate the two sets of devices to reduce the occupied space.

[0007] To achieve the above object, the technical solution of the present invention is: a pneumatic magnetic cut-off throttle device for the security of a steam turbine compressor unit, which has a pneumatic cut-off throttle. An intermediate support is installed on the upper part of the throttle housing of the pneumatic cut-off throttle. A hydraulic slide valve and a pneumatic piston are installed in the throttle housing. A gear-rack transmission mechanism is installed in the intermediate support. An air safety valve is installed on the side of the throttle housing, and the air safety valve is communicated with the upper chamber or the lower chamber of the pneumatic piston. An electromagnetic hydraulic mechanism is installed on the upper part of the intermediate support. The electromagnetic hydraulic mechanism has a magnetic force execution oil cylinder. The upper and lower chambers of the piston rod in the magnetic force execution oil cylinder are respectively connected to a pressure oil pump through a two-position four-way solenoid valve. The lower end of the piston rod passes through one side rack in the gear-rack transmission mechanism and is fixedly connected to the upper end of the pneumatic piston. This rack is linked to the other side rack in the gear-rack transmission mechanism through a gear. The other side rack is fixedly connected to the upper end of the hydraulic slide valve. The inner cavity of the hydraulic slide valve is connected to a power oil inlet, and the outer cavity is connected to a power oil outlet. A return oil port is provided below the inner cavity of the hydraulic slide valve.

[0008] Further, the air safety valve is connected to the exhaust port of the compressor of the steam turbine screw compressor unit and is provided with an overpressure exhaust port; the power oil inlet is connected to the high-pressure oil outlet of the steam turbine screw compressor unit; the power oil outlet is connected to the high-pressure oil inlet of the main steam valve of the steam turbine screw compressor unit; the return oil port is connected to the oil tank of the steam turbine screw compressor unit.

[0009] Further, when the exhaust pressure of the compressor exceeds the rated pressure, the air safety valve opens, and the compressed air introduced from the exhaust port enters the upper chamber of the pneumatic piston of the pneumatic cut-off throttle through a pipeline, causing the pneumatic piston to quickly move downward against the spring force. Then, through the gears and racks, the hydraulic slide valve is driven to move downward, thereby cutting off the high-pressure oil leading to the main steam valve and closing the main steam valve of the steam turbine for emergency shutdown. The high-pressure oil below the slide valve then flows into the oil tank from the bottom return oil port.

[0010] Further, when the exhaust pressure of the compressor rises to the overpressure limit value, the two-position four-way solenoid valve in the electromagnetic hydraulic mechanism receives an electric signal, triggering the electromagnetic hydraulic mechanism to act. The piston rod pushes the pneumatic piston downward, and then through the gears and racks, the hydraulic slide valve is driven to move upward, thereby cutting off the high-pressure oil leading to the main steam valve and closing the main steam valve of the steam turbine for emergency shutdown.

[0011] Further, when the two-position four-way solenoid valve receives the electric signal of remote quick shutdown, the two-position four-way solenoid valve makes the pressure oil inlet and return oil of the magnetic force execution oil cylinder reverse through a hydraulic block. The piston rod in the magnetic force execution oil cylinder drives the rack arranged above the piston in the air chamber of the pneumatic cut-off throttle, causing the pneumatic cut-off throttle to act and closing the main steam valve of the steam turbine for emergency shutdown.

[0012] The beneficial effects of the present invention are:

[0013] The pneumatic magnetic circuit breaker throttle device of the present invention has the following characteristics compared with the original "overpressure power-off quick shutdown protection" or "pneumatic circuit breaker throttle":

[0014] 1) The backpressure protection of the compressor can be achieved through the principles of pure hydraulic, pneumatic, and mechanical transmission, avoiding the failure of the backpressure protection function caused by the reliability problems of electrical components and the failure of the backpressure protection function caused by power-off;

[0015] 2) The "overpressure power-off quick shutdown protection" of the compressor backpressure can be achieved;

[0016] 3) The remote control (based on other protection signals or manual judgment) electric quick shutdown protection can be achieved;

[0017] 4) The piston of the hydraulic mechanism can be electrically actuated regularly or before starting the machine to prevent the inaction of the original pneumatic circuit breaker throttle caused by the jamming of the "pneumatic slide valve" of the pneumatic circuit breaker throttle. Description of the Drawings

[0018] Figure 1 is a structural sectional view of the pneumatic circuit breaker throttle device;

[0019] Figure 2 is Figure 1 the sectional view along A-A in;

[0020] Figure 3 is a structural sectional view of the pneumatic magnetic circuit breaker throttle device of the present invention;

[0021] Figure 4 is Figure 3 the sectional view along A-A in;

[0022] Figure 5 is Figure 4 the sectional view rotation along B-B in;

[0023] Figure 6 is the external shape schematic diagram of the pneumatic magnetic circuit breaker throttle device of the present invention;

[0024] Figure 7 is the application schematic diagram of the pneumatic magnetic circuit breaker throttle device of the present invention on the steam turbine screw compressor unit.

[0025] In the figure: 1. Air safety valve, 2. Pneumatic circuit breaker throttle, 3. Electromagnetic hydraulic mechanism, 4. Cover, 2-1. Throttle housing, 2-2. Rack and pinion transmission mechanism, 2-3. Hydraulic slide valve, 2-4. Pneumatic piston, 2-5. Intermediate support, 3-1. Two-position four-way solenoid valve, 3-2. Oil cylinder, 3-3. Piston rod, 10. Pneumatic magnetic circuit breaker throttle device. Detailed Embodiments

[0026] The present invention will be further described below in conjunction with the drawings and embodiments.

[0027] As Figures 3 to 7 shown, a pneumatic magnetic circuit breaker throttle device 10 consists of three major parts: an air safety valve 1, a pneumatic circuit breaker throttle 2, and an electromagnetic hydraulic mechanism 3. The pneumatic circuit breaker throttle 2 consists of a throttle housing 2-1, a gear-rack transmission mechanism 2-2, a hydraulic slide valve 2-3, a pneumatic piston 2-4, an intermediate support 2-5, etc. The upper part of the throttle housing 2-1 is equipped with an intermediate support 2-5. Inside the throttle housing 2-1, there are a hydraulic slide valve 2-3 and a pneumatic piston 2-4. Inside the intermediate support 2-5, there is a gear-rack transmission mechanism 2-2. The air safety valve 1 is integrally installed on the side of the throttle housing 2-1 of the pneumatic circuit breaker throttle 2 and is connected to the upper or lower chamber of the pneumatic piston 2-4. The electromagnetic hydraulic mechanism 3 consists of a two-position four-way solenoid valve 3-1, an oil cylinder 3-2, and a piston rod 3-3. The electromagnetic hydraulic mechanism 3 is installed on top of the intermediate support 2-5. The upper and lower chambers of the piston rod 3-3 inside the oil cylinder 3-2 are respectively connected to a pressure oil pump through the two-position four-way solenoid valve 3-1. The lower end of the piston rod 3-3 extends into the rack hole on the pneumatic piston 2-4 of the pneumatic circuit breaker throttle and is connected to one side of the rack in the gear-rack transmission mechanism 2-2. This rack is connected to the other side of the rack in the gear-rack transmission mechanism 2-2 through a gear, and the other side of the rack is connected to the slide rod of the hydraulic slide valve 2-3. The inner cavity of the hydraulic slide valve 2-3 is connected to the power oil inlet P, and the outer cavity is connected to the power oil outlet S. There is an oil return port Q below the inner cavity of the hydraulic slide valve 2-3.

[0028] The air safety valve is connected to the exhaust port R of the compressor of the turbo-screw air compressor unit; there is also an overpressure exhaust port W on the air safety valve; the power oil inlet is connected to the high-pressure oil outlet of the turbo-screw air compressor unit; the power oil outlet is connected to the high-pressure oil inlet of the main steam valve of the turbo-screw air compressor unit; the oil return port is connected to the oil tank of the turbo-screw air compressor unit.

[0029] When the exhaust pressure of the compressor exceeds the rated pressure and rises to a certain overpressure limit value for some reason, the air safety valve opens, and the compressed air introduced from the exhaust port enters the upper chamber of the "pneumatic piston" of the pneumatic circuit breaker throttle through a pipeline. The "pneumatic piston" quickly moves downward against the spring force, and then drives the slide valve upward through the gear and rack, thereby cutting off the high-pressure oil leading to the main steam valve and closing the main steam valve of the steam turbine for emergency shutdown. The high-pressure oil below the slide valve then flows into the oil tank from the bottom oil return port.

[0030] When the exhaust pressure of the compressor rises to a certain overpressure limit value, an electrical signal is obtained to trigger the electromagnetic hydraulic mechanism to act. The piston rod pushes the "pneumatic piston" downward, and then drives the slide valve upward through the gear and rack, thereby cutting off the high-pressure oil leading to the main steam valve and closing the main steam valve of the steam turbine for emergency shutdown.

[0031] When the two-position four-way solenoid valve receives the electrical signal (switch quantity trigger) for remote quick shutdown, it makes the pressure oil inlet and oil return of the magnetic actuator cylinder reverse through the hydraulic block. The piston rod in the magnetic actuator cylinder drives the rack arranged on the piston of the pneumatic cut-off throttle air chamber through the guiding device, causing the pneumatic cut-off throttle to act and closing the main steam valve of the steam turbine for emergency shutdown.

[0032] The pneumatic magnetic cut-off throttle can separately implement the compressor backpressure protection function of the pneumatic cut-off throttle device and the execution function of remote quick shutdown without mutual influence. It can also regularly or electrically operate the piston of the hydraulic mechanism before starting the machine to prevent the non-action of the original pneumatic cut-off throttle caused by the jamming of the "pneumatic slide valve" of the pneumatic cut-off throttle.

Claims

1. A pneumatic magnetic cut-off throttle device for the security of a steam turbine compressor unit, having a pneumatic cut-off throttle, with an intermediate support installed on the upper part of the throttle housing of the pneumatic cut-off throttle, a hydraulic slide valve and a pneumatic piston installed inside the throttle housing, and a gear-rack transmission mechanism installed inside the intermediate support, characterized in that: An air safety valve is installed on the side of the throttle housing, and the air safety valve is communicated with the upper chamber of the pneumatic piston; an electromagnetic hydraulic mechanism is installed on the upper part of the intermediate support. The electromagnetic hydraulic mechanism has a magnetic force actuator cylinder. The upper and lower chambers of the piston rod in the magnetic force actuator cylinder are respectively connected to a pressure oil pump through a two-position four-way solenoid valve. The lower end of the piston rod passes through one side rack in the gear-rack transmission mechanism and is fixedly connected to the upper end of the pneumatic piston. This rack is linked to the other rack on the other side of the gear-rack transmission mechanism through a gear, and the other rack is fixedly connected to the upper end of the hydraulic slide valve. The inner cavity of the hydraulic slide valve is connected to the power oil inlet, the outer cavity is connected to the power oil outlet, and an oil return port is arranged below the inner cavity of the hydraulic slide valve; the air safety valve is connected to the exhaust port of the compressor of the turbo-compressor unit and is provided with an overpressure exhaust port; the power oil inlet is connected to the high-pressure oil outlet of the turbo-compressor unit; the power oil outlet is connected to the high-pressure oil inlet of the main steam valve of the turbo-compressor unit; the oil return port is connected to the oil tank of the turbo-screw compressor unit; the pneumatic magnetic cut-off throttle device realizes the compressor back-pressure protection function and the remote control quick shutdown execution function of the pneumatic cut-off throttle device respectively without affecting each other.

2. The pneumatic magnetic cut-off throttle device for security of the steam turbine compressor unit according to claim 1, characterized in that: When the exhaust pressure of the turbo-compressor unit exceeds the rated pressure, the air safety valve opens, and the compressed air introduced from the exhaust port enters the upper chamber of the pneumatic piston of the pneumatic cut-off throttle through a pipeline, causing the pneumatic piston to quickly move downward against the spring force, and then driving the hydraulic slide valve to move upward through the gear and rack, so as to cut off the high-pressure oil leading to the main steam valve and close the main steam valve of the steam turbine for emergency shutdown. The high-pressure oil below the slide valve then flows into the oil tank from the bottom oil return port.

3. The pneumatic magnetic cut-off throttle device for security of steam turbine compressor unit according to claim 2, characterized in that: When the exhaust pressure of the turbo-compressor unit rises to the overpressure limit value, the two-position four-way solenoid valve in the electromagnetic hydraulic mechanism receives an electrical signal and triggers the electromagnetic hydraulic mechanism to act. The piston rod pushes the pneumatic piston downward, and then drives the hydraulic slide valve to move upward through the gear and rack, so as to cut off the high-pressure oil leading to the main steam valve and close the main steam valve of the steam turbine for emergency shutdown.

4. The pneumatic magnetic cut-off throttle device for security of steam turbine compressor unit according to claim 1, characterized in that: When the two-position four-way solenoid valve receives the electrical signal of remote control quick shutdown, the two-position four-way solenoid valve makes the pressure oil inlet and return oil of the magnetic force actuator cylinder reverse through the hydraulic block. The piston rod in the magnetic force actuator cylinder drives the rack arranged above the piston in the air chamber of the pneumatic cut-off throttle, causing the pneumatic cut-off throttle to act and closing the main steam valve of the steam turbine for emergency shutdown.

Images