A bearing cavity sealing air induction conversion device

Abstract

The application provides a bearing cavity sealing air guide conversion device, comprising: a shell assembly, the shell assembly has a first inlet for guiding air from a rear stage of a compressor, a second inlet for guiding air from a front stage of the compressor, a third inlet for guiding air from the same source as the first inlet, and an outlet connected with a sealing cavity of an engine bearing cavity, and a valve cavity and a piston cavity are arranged in the shell assembly; a valve assembly and a piston assembly, a valve of the valve assembly is arranged in the valve cavity, the piston assembly is arranged in the piston cavity, and the valve assembly and the piston assembly can move simultaneously; an electromagnetic control valve is arranged at the third inlet, and the electromagnetic control valve can control the opening and closing of the third inlet. The air guide conversion device of the application guides the air from the rear stage of the compressor to realize the sealing of the engine bearing cavity in a low state; and guides the air from the front stage of the compressor to realize the sealing of the engine bearing cavity in a high state.

Description

Technical Field

[0001] This application belongs to the field of aero-engines or gas turbines, and specifically relates to a bearing cavity sealing and bleed air conversion device. Background Technology

[0002] The air system is a crucial component of an aero-engine or gas turbine. It is a complex and large-scale flow system responsible for cooling and homogenizing high-temperature components within the engine, sealing and insulating the bearing lubrication system, and balancing the axial load on the bearings. The proper and reliable operation of the air system has a significant impact on engine performance, reliability, and the lifespan of critical components.

[0003] Generally, gas turbines use cool air from the compressor side for turbine cooling, pivot sealing, and balancing axial forces. However, due to the limitation of the compressor's single bleed air position, the bleed air pressure and pivot sealing pressure may mismatch under certain engine operating conditions. This can lead to insufficient sealing pressure differential and leakage in the lubricating oil chamber. Alternatively, excessive sealing pressure differential can cause a decrease in engine performance, increase the lubricating oil chamber pressure, and increase the amount of oil and gas flowing through the ventilation pipe to the oil mist separator, resulting in increased lubricating oil consumption. Summary of the Invention

[0004] The purpose of this application is to provide a bearing cavity sealing and bleed air conversion device to solve or alleviate at least one of the problems in the prior art.

[0005] The technical solution of this application is: a bearing cavity sealing and venting conversion device, comprising:

[0006] The housing assembly has a first inlet for drawing air from the compressor rear stage bleed port, a second inlet for drawing air from the compressor front stage bleed port, a third inlet for drawing air from the same source as the first bleed port, and an outlet connected to the sealing cavity of the engine bearing cavity, and the housing assembly is provided with a valve cavity and a piston cavity.

[0007] A valve assembly and a piston assembly, wherein the valve of the valve assembly is disposed within a valve cavity, and the piston assembly is disposed within a piston cavity, and the valve assembly and the piston assembly are capable of moving simultaneously; and

[0008] An electromagnetic control valve is installed at the third inlet, which can control the opening and closing of the third inlet;

[0009] When the gas turbine is in a low state and the pressure of each stage blade of the compressor has not been effectively established, the electromagnetic control valve controls the third inlet to close, the first inlet bleed air pressure is greater than the second inlet bleed air pressure, the second inlet is closed, the first inlet is connected to the outlet, and the engine bearing cavity sealing cavity bleeds air from the bleed air port of the rear stage of the compressor.

[0010] When the gas turbine is in a certain state and the pressure of each stage blade of the compressor is effectively established, the electromagnetic control valve controls the third inlet to open. The bleed air pressure of the first inlet is less than the sum of the bleed air pressures of the second and third inlets, so the first inlet is closed. The second inlet is connected to the outlet, and the engine bearing cavity sealing cavity draws air from the bleed air port of the compressor front stage.

[0011] In an optional embodiment of this application, the first inlet, the second inlet, the third inlet, and the outlet are distributed on different surfaces of the housing assembly.

[0012] In an optional embodiment of this application, the first inlet is connected to the compressor rear stage casing via a second pipe adapted to the compressor rear stage blades, and the second inlet is connected to the compressor front stage casing via a first pipe adapted to the compressor front stage blades. The number of stages of the compressor rear stage blades and compressor front stage blades is set based on the pressure level differences of each elementary stage blade of the compressor.

[0013] In an optional embodiment of this application, the valve assembly includes a valve stem, a spring, and a pin. The valve stem is disposed in the valve cavity. The stem portion of the valve stem passes through the housing assembly and extends into the piston cavity and is fixedly connected to the piston assembly. The spring is disposed in the piston cavity to provide elastic force to the valve assembly. The pin is mounted on the housing assembly.

[0014] In an optional embodiment of this application, a sealing device is provided between the piston assembly and the housing assembly and / or between the ejector pin and the housing assembly.

[0015] In an optional embodiment of this application, the sealing device includes a rubber ring or a graphite ring.

[0016] In an optional embodiment of this application, a micro switch is also included, which is mounted on the housing assembly and adapted to the position of the ejector pin, and can be activated by the ejector pin.

[0017] In an optional embodiment of this application, the cross-sectional area of ​​the valve cavity is smaller than the cross-sectional area of ​​the piston cavity.

[0018] In an optional embodiment of this application, the housing assembly further includes an end cap and a piston chamber cover, etc., and the end cap or piston chamber cover is fixedly connected to the body of the housing assembly to form an overall structure of the housing assembly.

[0019] The bleed air switching device provided in this application introduces bleed air from the downstream stage of the compressor to seal the engine bearing cavity in a low-pressure state, preventing oil and gas leakage in the bearing cavity due to low sealing air pressure. In a high-pressure state, it introduces bleed air from the upstream stage of the compressor to seal the engine bearing cavity, avoiding problems such as sealing pressure mismatch caused by still using bleed air from the downstream stage of the compressor. On the one hand, it avoids excessive oil consumption caused by excessive sealing air pressure, sealing pressure mismatch, and excessive ventilation in the bearing cavity. On the other hand, by switching the air source, it limits the amount of bleed air from the downstream stage of the compressor, thereby improving the overall thermal efficiency of the engine. Attached Figure Description

[0020] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0021] Figure 1 This is a schematic diagram of the overall gas conversion device of this application.

[0022] Figure 2 This is a schematic diagram of the housing assembly of this application.

[0023] Figure 3 This is a schematic diagram of the air venting location for the housing assembly in this application.

[0024] Figure 4 This is a schematic diagram of the gas conversion device of this application.

[0025] Figure 5 A schematic diagram showing the introduction of bleed air into the compressor stage of the bleed air conversion device of this application.

[0026] Figure 6 A schematic diagram showing the introduction of bleed air into the compressor front stage of the bleed air conversion device of this application.

[0027] Figure label:

[0028] 1-Housing assembly

[0029] 11-First Import

[0030] 12-Second Import

[0031] 13-Third Import

[0032] 14-Exports

[0033] 15-Positioning cavity

[0034] 16-Piston Chamber

[0035] 2-Vault assembly

[0036] 21-gate lever

[0037] 22-Spring

[0038] 23-Thimble

[0039] 3-Piston Assembly

[0040] 31-Sealing device

[0041] 4-Solenoid control valve

[0042] 5-Micro switch

[0043] 61-First Pipeline

[0044] 62-Second Pipeline Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0046] This application provides a bearing cavity sealing bleed air switching device, which is used to realize bleed air switching under different engine operating conditions, solves the design problem of air system pivot sealing under small sealing pressure difference, and provides a technical solution for the engine to meet the requirements of high performance, high reliability, long service life and low lubricating oil consumption.

[0047] like Figure 1 As shown, the bearing cavity sealing and venting conversion device provided in this application includes: a housing assembly 1, a valve assembly 2, a piston assembly 3, an electromagnetic control valve 4, and a micro switch 5.

[0048] like Figure 2 As shown, the housing assembly 1 has three inlets and one outlet, namely a first inlet 11, a second inlet 12, a third inlet 13, and an outlet 14. Typically, the first inlet 11, the second inlet 12, the third inlet 13, and the outlet 14 are distributed on different surfaces of the housing assembly 1 to facilitate the installation of pipelines at each inlet or outlet. For example, in this embodiment of the application, the first inlet 11, the third inlet 13, and the outlet 14 are distributed on three side planes of the housing assembly 1, and the second inlet 12 is located on the left end face of the housing 1.

[0049] Combination Figure 3As shown, the first inlet 11 is connected to the compressor rear stage casing via a second pipe 62 adapted to the compressor rear stage blades, thus allowing bleed air from the compressor rear stage bleed port. The second inlet 12 is connected to the compressor front stage casing via a first pipe 61 adapted to the compressor front stage blades, thus allowing bleed air from the compressor front stage bleed port. The third bleed port 13 shares the same bleed air source as the first bleed port 11, using compressor rear stage bleed air as control air to control the switching of the bleed air conversion device. The outlet 14 is connected to the engine bearing cavity sealing cavity via a pipe. Under low operating conditions of the gas turbine, outlet 14 introduces compressor rear stage bleed air through the first inlet 11; under high operating conditions, outlet 14 introduces compressor front stage bleed air through the second inlet 12.

[0050] It should be noted that the terms "compressor front stage" and "compressor rear stage" in this application are relative concepts. For example, in this embodiment of the application, the compressor rear stage blade is the compressor fifth stage rotor blade, while the compressor front stage blade is the compressor second stage rotor blade. The compressor fifth stage rotor blade is located further back than the compressor second stage rotor blade.

[0051] Continue to refer to Figure 4 As shown, the internal configuration of the housing assembly 1 forms two cavities: a valve cavity 15 on the left and a piston cavity 16 on the right. The cross-sectional area of ​​the valve cavity 15 is smaller than that of the piston cavity 16. The valve cavity 15 is connected to the first inlet 11, the second inlet 12, and the outlet 14, while the piston cavity 16 is connected to the third inlet 13.

[0052] In some embodiments of this application, the housing assembly 1 further includes an inlet and / or outlet end cap and a piston chamber cover, etc., which are fixedly connected to the housing body to form an overall structure of the housing assembly.

[0053] The valve assembly 2 includes a valve stem 21, a spring 22, and a ejector pin 23. The valve stem 21 is disposed within the valve cavity 15, and its stem portion extends into the piston cavity 16. The spring 22 is disposed within the piston cavity 16 to provide elastic force to the valve stem 21. The ejector pin 23 is mounted on the right piston cavity cover of the housing assembly 1 and is located within the piston cavity 16. The valve stem 21 can push the ejector pin 23 to move.

[0054] The piston assembly 3 is disposed in the piston chamber 16 and is fixedly connected to the valve stem 21. Its outer side is adapted to the inner surface of the housing assembly 1. The spring 22 is supported on the piston assembly 3 and can provide elastic force to the valve stem 21.

[0055] In some embodiments of this application, a sealing device 31 can be provided between the piston assembly 3 and the housing assembly 1, and between the ejector pin 23 and the housing assembly 1, to achieve sealing of the corresponding cavities. The sealing device 31 can be a rubber ring or a graphite ring.

[0056] The electromagnetic control valve 4 is located at the third inlet 13, and the opening and closing of the third inlet 13 can be controlled by the electromagnetic control valve 4.

[0057] The micro switch 5 is mounted on the piston chamber cover of the housing assembly 1 and is adapted to the position of the ejector pin 23. The micro switch 5 can be activated by the ejector pin 23.

[0058] The working process of the bleed air conversion device in this application is as follows:

[0059] 1) such as Figure 5 As shown, when the gas turbine is in a low operating condition, the compressor speed is low and the pressure ratio is small. The pressure at each stage blade is not effectively established. At the initial operation, the solenoid valve 3 is energized. The third inlet 13 is closed by the solenoid control valve 4. Control gas (i.e., compressor backstage bleed gas) cannot be introduced into the piston chamber 16. The piston assembly 3 is only subjected to the leftward spring force. The valve in the valve assembly 2 is subjected to the combined action of the compressor backstage bleed gas introduced to the left by the first inlet 11 and the compressor frontstage bleed gas introduced to the right by the second inlet 12. Since the force of the compressor backstage bleed gas is much greater than that of the compressor frontstage bleed gas, the valve assembly 2 and the piston assembly 3 are subjected to the leftward resultant force and are at the left limit position. At this time, the valve assembly 2 closes the second inlet 12 of the compressor frontstage bleed gas, so that the first inlet 11 of the compressor backstage bleed gas is connected to the outlet 14. At this time, the bleed gas conversion device introduces the compressor backstage bleed gas to seal the engine bearing chamber.

[0060] 2) such as Figure 6As shown, when the gas turbine is loaded to a certain operating condition (or the compressor speed increases to a certain speed) and the switching conditions are met, the compressor speed is high and the pressure ratio is high. The pressure of each elementary stage blade has been effectively established. The control solenoid valve 3 sends a control signal to de-energize the solenoid valve 4 and open the third inlet 13. At this time, control gas (i.e., the bleed gas from the downstream stage of the compressor) is introduced into the piston chamber 16. Since the area of ​​the piston assembly 3 is much larger than the area of ​​the valve, the piston assembly 3 overcomes the spring force, friction force, and the bleed gas from the first inlet 11 and the second inlet 11 on the valve stem 21. The combined force of the air intake at inlet 12 causes the valve assembly 2 to move to the right. When the valve assembly 2 moves to the right limit position, the valve assembly 2 closes the first inlet 11 of the compressor rear stage bleed air, making the second inlet 12 of the compressor front stage bleed air connected to the outlet 14. At this time, the bleed air conversion device introduces the compressor front stage bleed air to seal the engine bearing cavity. When the valve rod 21 continues to move to the right and contacts the ejector pin 23, the valve rod 23 pushes the ejector pin 23 to continue moving to the right and touches the micro switch 5. The micro switch 5 outputs a conversion signal indicating that the valve is switched to the position.

[0061] The bleed air switching device provided in this application introduces bleed air from the downstream stage of the compressor to seal the engine bearing cavity in a low-pressure state, preventing oil and gas leakage in the bearing cavity due to low sealing air pressure. In a high-pressure state, it introduces bleed air from the upstream stage of the compressor to seal the engine bearing cavity, avoiding problems such as sealing pressure mismatch caused by still using bleed air from the downstream stage of the compressor. On the one hand, it avoids excessive oil consumption caused by excessive sealing air pressure, sealing pressure mismatch, and excessive ventilation in the bearing cavity. On the other hand, by switching the air source, it limits the amount of bleed air from the downstream stage of the compressor, thereby improving the overall thermal efficiency of the engine.

[0062] The bleed air conversion device provided in this application can achieve the optimal bleed air pressure at the engine pivot sealing point under different operating conditions. It can be reasonably matched based on the differences in pressure levels of the compressor's elementary stage blades, such as a two / five-stage conversion device or a three / seven-stage conversion device.

[0063] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A bearing cavity sealing and venting conversion device, characterized in that, include: The housing assembly (1) has a first inlet (11) for drawing air from the compressor rear stage bleed port, a second inlet (12) for drawing air from the compressor front stage bleed port, a third inlet (13) for drawing air from the same source as the first inlet (11), and an outlet (14) connected to the sealing cavity of the engine bearing cavity, and the housing assembly (1) has a valve cavity (15) and a piston cavity (16) inside. A valve assembly (2) and a piston assembly (3), wherein the valve of the valve assembly (2) is disposed in a valve cavity (15), and the piston assembly (3) is disposed in a piston cavity (16), and the valve assembly (2) and the piston assembly (3) are capable of moving simultaneously; and An electromagnetic control valve (4) is provided at the third inlet (13), which can control the opening and closing of the third inlet (13); The valve assembly (2) includes a valve rod (21), a spring (22) and a pin (23). The valve of the valve rod (21) is disposed in the valve cavity (15). The rod of the valve rod (21) passes through the housing assembly (1) and extends into the piston cavity (16) and is fixedly connected to the piston assembly (3). The spring (22) is disposed in the piston cavity (16) to provide elastic force to the valve assembly (2). The pin (23) is mounted on the housing assembly (1). When the gas turbine is in a low state and the pressure of each stage blade of the compressor is not effectively established, the electromagnetic control valve (4) controls the third inlet (13) to close, the bleed pressure of the first inlet (11) is greater than the bleed pressure of the second inlet (12), the second inlet (12) is closed, the first inlet (11) is connected to the outlet (14), and the engine bearing cavity sealing cavity bleeds air from the bleed port of the rear stage of the compressor; When the gas turbine is in a certain state and the pressure of each elementary stage blade of the compressor is effectively established, the electromagnetic control valve (4) controls the third inlet (13) to open. The bleed pressure of the first inlet (11) is less than the sum of the bleed pressures of the second inlet (12) and the third inlet (13). Bleed air from the rear stage of the compressor is introduced into the piston chamber (16). Since the area of ​​the piston assembly (3) is much larger than the area of ​​the valve, the first inlet (11) is closed. The second inlet (12) is connected to the outlet (14). The sealing chamber of the engine bearing cavity is bleed from the bleed port of the front stage of the compressor.

2. The bearing cavity sealing and evacuation conversion device as described in claim 1, characterized in that, The first inlet (11), the second inlet (12), the third inlet (13) and the outlet (14) are distributed on different surfaces of the housing assembly (1).

3. The bearing cavity sealing and evacuation conversion device as described in claim 1, characterized in that, The first inlet (11) is connected to the compressor rear stage casing via a second pipe (62) adapted to the compressor rear stage blades, and the second inlet (12) is connected to the compressor front stage casing via a first pipe (61) adapted to the compressor front stage blades. The number of stages of the compressor rear stage blades and the compressor front stage blades is set based on the pressure level difference of each elementary stage blade of the compressor.

4. The bearing cavity sealing and evacuation conversion device as described in claim 1, characterized in that, A sealing device (31) is provided between the piston assembly (3) and the housing assembly (1) and / or between the ejector pin (23) and the housing assembly (1).

5. The bearing cavity sealing and venting conversion device as described in claim 4, characterized in that, The sealing device includes a rubber ring or a graphite ring.

6. The bearing cavity sealing and venting conversion device as described in claim 4, characterized in that, It also includes a micro switch (5), which is mounted on the housing assembly (1) and adapted to the position of the ejector pin (23), and can be activated by the ejector pin (23).

7. The bearing cavity sealing and venting conversion device as described in claim 1, characterized in that, The cross-sectional area of ​​the valve cavity (15) is smaller than that of the piston cavity (16).

8. The bearing cavity sealing and evacuation conversion device as described in claim 1, characterized in that, The housing assembly (1) also includes an end cap and a piston chamber cap, which are fixedly connected to the body of the housing assembly to form an overall structure of the housing assembly.

Images