Radial clearance control structure and method based on rotor bleed air

Abstract

The invention relates to the field of gas compressors and gas guide flow path design thereof, and discloses a radial clearance control structure and method based on rotor gas guide, the flow area of an exhaust hole is adjusted through a control valve according to different gas compressor rotating speeds, so that gas guide amount adjustment under different gas compressor rotating speeds is achieved; mainstream gas in a gas compressor main runner is guided into a gas compressor rotor disc cavity or a turbine rotor disc cavity, the temperature of a rotor in a hot state when an engine is started is adjusted, self-adaptive adjustment of the temperature of the gas compressor disc cavity is achieved, and therefore the elongation of a gas compressor wheel disc or a turbine disc is adjusted; the speed of the air compressor rotor blade or the turbine rotor blade reaching the hot state position is increased, so that the starting and warming time of an aero-engine is shortened, and the purposes of energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The present invention relates to the field of compressors and the design of their air intake flow paths, and discloses a radial clearance control structure and method based on rotor air extraction. Background Art

[0002] As one of the core components of an aero-engine, the high-pressure compressor is mainly a mechanical device that transmits mechanical energy to the gas and completes the compression process of the gas working medium in the engine thermodynamic cycle to increase the gas pressure. Its performance has a crucial impact on the entire engine. The high-pressure compressor provides most of the cycle pressure ratio, and its load, efficiency level, and stable operating margin directly affect the overall fuel consumption rate, operating range, and reliability of the engine.

[0003] The radial clearance between the rotor and stator of the high-pressure compressor is an important factor for the aerodynamic performance, stability, and working reliability of the compressor. However, in engineering design, to ensure the safe and reliable operation of the aero-compressor under various working conditions, the traditional design of the radial clearance between the rotor of the compressor and the corresponding casing adopts its most demanding working state for design, resulting in a relatively small radial clearance of the high-pressure compressor only under some large working states, while the radial clearance is relatively large under other working states, seriously affecting the aerodynamic performance and operating margin of the high-pressure compressor under low working states. Summary of the Invention

[0004] The purpose of the present invention is to provide a radial clearance control structure and method based on rotor air extraction, which can accelerate the speed of the compressor rotor blades or turbine rotor blades reaching the hot state position, so as to shorten the start-up warm-up time of the aero-engine and achieve the purpose of energy conservation and emission reduction.

[0005] To achieve the above technical effects, the technical solution adopted by the present invention is: A radial clearance control structure based on rotor air extraction, comprising: An air extraction chamber, which is communicated with the inner cavity of the compressor stator casing and is used to introduce a part of the mainstream air flow of the compressor into the air extraction chamber; An air extraction passage, which is communicated with the air extraction chamber and is used to guide the air flow in the air extraction chamber into the compressor rotor disk cavity or the turbine rotor disk cavity; A control valve, which is arranged on the air extraction passage and is used to control the air extraction volume of the air extraction passage.

[0006] Further, the control valve is an electric control valve, and the electric control valve is adjusted by a controller to control the opening degree of the air extraction passage.

[0007] Further, it further includes a temperature sensing component, which is used to obtain the temperature data of the compressor rotor disk or the turbine rotor disk, and transmit the temperature data to the controller. The controller is used to control the control valve according to the difference between the temperature data transmitted by the temperature sensing component and the preset temperature of the corresponding compressor rotor disk or turbine rotor disk, so as to control the opening degree of the air extraction channel.

[0008] Further, the air extraction channel is an air extraction pipe radially fixed on the compressor rotor; exhaust holes are provided on the air extraction pipe, and the exhaust holes are used to introduce the mainstream gas entering the air extraction channel into the compressor disk cavity; the control valve includes a piston arranged in the air extraction pipe, and the initial radial position of the inner end face of the piston in the radial direction is located inside the exhaust hole. A through hole for air flow is provided on the piston. When the piston is in the initial position and in the cold state, the exhaust hole is completely closed, and the flow area of the exhaust hole gradually increases at the preset engine speed; a limiting component is arranged between the piston and the air inlet position of the air extraction pipe, and a compression spring is arranged between the limiting component and the outer end face of the piston in the radial direction.

[0009] Further, the piston is of a U-shaped structure, and the side wall of the piston is used to cooperate with the exhaust hole to adjust the flow area of the exhaust hole, and the through hole is opened at the U-shaped bottom of the piston.

[0010] To achieve the above technical effects, the present invention also provides a radial clearance control method based on rotor air extraction. This method is based on the above-mentioned radial clearance control structure based on rotor air extraction, and includes: Obtain the total air temperature of the air extraction cavity at the air extraction position of the compressor at different speeds, and construct a first function analysis model between the total air temperature and the speed; According to the engine assessment condition speed, use the first function analysis model to analyze and obtain the total air temperature of the air extraction position corresponding to the assessment condition speed; Under the condition of the engine assessment condition speed, test the time required to heat the rotor disk from room temperature to the preset temperature at different control valve opening degrees, and construct a relationship function between the rotor disk temperature and time corresponding to different control valve opening degrees under the condition of the assessment condition speed according to the assessment condition speed and the total air temperature of the air extraction position at the corresponding speed; According to the upper limit time required to adjust the rotor disk from room temperature to the design temperature at the assessment condition speed, analyze and obtain the minimum opening degree of the control valve required on the relationship function.

[0011] Further, the relationship function between the rotor disk temperature and time corresponding to different control valve opening degrees under the condition of the assessment condition speed is , where is the control valve opening degree, To examine the total airflow temperature at the bleed air position under the operating speed conditions, is the initial temperature of the rotor disk, is the preset temperature of the rotor disk, The time required to heat the rotor disk from room temperature to the preset temperature according to design requirements.

[0012] Furthermore, a temperature sensing component is used to obtain temperature data of a compressor rotor disk or a turbine rotor disk, so as to transmit the temperature data to the controller. The controller controls the control valve according to the difference between the temperature data transmitted by the temperature sensing component and the preset temperature of the corresponding compressor rotor disk or turbine rotor disk, so as to control the opening of the bleed air passage.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adjusts the flow area of ​​the exhaust hole according to different compressor speeds through a control valve to achieve adjustment of the bleed air volume under different compressor speeds, introduces the mainstream gas in the compressor main flow channel into the compressor rotor disc cavity or the turbine rotor disc cavity, adjusts the hot temperature of the rotor when the engine is started, and achieves adaptive adjustment of the compressor disc cavity temperature, thereby adjusting the elongation of the compressor impeller or the turbine disc, and accelerating the speed at which the compressor rotor blades or the turbine rotor blades reach the hot position, thereby shortening the start-up warm-up time of the aircraft engine and achieving the purpose of energy saving and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of radial clearance control structure based on rotor air bleed in the embodiment; Figure 2 The schematic diagram of the radial clearance control structure is formed by the bleed air passage being a bleed air pipe structure fixed on the compressor rotor; Figure 3 It is a structural schematic diagram of an air bleed channel and a control valve; Among them, 1. air bleed cavity; 2. stator casing; 3. air bleed channel; 4. compressor rotor disc cavity; 5. turbine rotor disc cavity; 6. control valve; 7. exhaust hole; 8. piston; 9. through hole; 10. limit assembly; 11. compression spring. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below in conjunction with the embodiments and drawings. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0016] Example See also Figure 1 , a radial clearance control structure based on rotor air induction, comprising: An air extraction cavity 1, which is communicated with the inner cavity of the compressor stator casing 2, is used to introduce part of the mainstream air flow of the compressor into the air extraction cavity 1; An air extraction channel 3, which is communicated with the air extraction cavity 1, is used to introduce the air flow in the air extraction cavity 1 into the compressor rotor disk cavity 4 or the turbine rotor disk cavity 5; A control valve 6, which is arranged on the air extraction channel 3, is used to control the air extraction volume of the air extraction channel 3.

[0017] In this embodiment, the control valve 6 adjusts the flow area of the exhaust hole 7 according to different compressor speeds to realize the adjustment of the air extraction volume at different compressor speeds, introduce the mainstream gas in the compressor main flow path into the compressor rotor disk cavity 4 or the turbine rotor disk cavity 5, adjust the temperature of the rotor hot state during engine startup, realize the adaptive adjustment of the compressor disk cavity temperature, thereby adjust the elongation of the compressor disk or the turbine disk, and accelerate the speed of the compressor rotor blade or the turbine rotor blade reaching the hot state position, so as to shorten the warm-up time of the aeroengine startup and achieve the purpose of energy conservation and emission reduction.

[0018] The control valve 6 of this embodiment is an electric control valve, and the electric control valve is adjusted by a controller to control the opening degree of the air extraction channel, and can quickly respond according to the real-time working state of the engine to ensure that the best air extraction volume control can be realized at different speeds, so as to accurately adjust the air flow rate entering the compressor rotor disk cavity 4 or the turbine rotor disk cavity 5.

[0019] In this embodiment, a temperature sensing component is further included. The temperature sensing component is used to obtain the temperature data of the compressor rotor disk or the turbine rotor disk, and transmit the temperature data to the controller. The controller is used to control the control valve 6 according to the difference between the temperature data transmitted by the temperature sensing component and the preset temperature of the corresponding compressor rotor disk or turbine rotor disk, so as to control the opening degree of the air extraction channel. By setting the preset temperature of the corresponding rotor disk inside the controller, when the temperature data transmitted by the temperature sensing component is higher or lower than the preset temperature value, the controller will immediately calculate the temperature difference and accordingly adjust the opening degree of the control valve 6, thereby dynamically adjusting the air extraction volume of the air extraction channel 3.

[0020] The air extraction channel 3 in the present invention can be installed outside the compressor, fixed on the compressor stator casing 2, and communicated from the outside of the compressor to the compressor rotor disk cavity 4 (such as Figure 1 ); or a trachea structure fixed on the compressor rotor can be directly adopted (such as Figure 2 ).

[0021] Such as Figure 3, in some other embodiments, an air extraction pipe structure fixed on the compressor rotor may also be used as the air extraction channel 3, that is, the air extraction channel 3 is an air extraction pipe fixed on the compressor rotor along the radial direction; an exhaust hole 7 is provided on the air extraction pipe, and the exhaust hole 7 is used to introduce the mainstream gas entering the air extraction channel 3 into the compressor disk cavity; the control valve 6 includes a piston 8 disposed in the air extraction pipe, the initial radial position of the inner end face of the piston 8 in the radial direction is located inside the exhaust hole 7, a through hole 9 for air flow to pass through is provided on the piston 8, the initial position of the piston 8 completely closes the exhaust hole 7 in the cold state, and the flow area of the exhaust hole 7 gradually increases at a preset engine speed; a limiting component 10 is provided between the piston 8 and the air inlet position of the air extraction pipe, and a compression spring 11 is provided between the limiting component 10 and the outer end face of the piston 8 in the radial direction. Since the inner end face of the piston 8 in the radial direction is located outside the exhaust hole 7, in the medium and low speed operating conditions, the control valve 6 is in a small opening degree, so as to allow the air extraction airflow to reach the compressor disk cavity, heat the engine disks at all levels that are difficult to heat, quickly adjust the disk center temperature, thereby reducing the tip clearance and accelerating the clearance reaching time. When the compressor starts to operate at high speed, the control valve 6 is in a large opening degree or even fully open, so as to increase the air extraction airflow rate, thereby enhancing the heat transfer in the flow channel in the disk cavity at high speed, controlling the disk body temperature, and reducing the risk of rubbing during the transition state.

[0022] The piston 8 in this embodiment is of a U-shaped structure. The side wall of the piston 8 is used to cooperate with the exhaust hole 7 to adjust the flow area of the exhaust hole 7, and the through hole 9 is opened at the U-shaped bottom of the piston 8. The through hole 9 at the U-shaped bottom plays a role in allowing air flow to pass through. During the operation of the engine, the piston 8 moves radially under the combined action of centrifugal force and spring elastic force. At different speeds, the piston 8 has different displacement amounts, so that the overlapping degree of the side wall of the U-shaped structure and the exhaust hole 7 will change accordingly, thereby realizing the adaptive adjustment of the air flow rate.

[0023] Based on the same inventive concept, this embodiment also provides a radial clearance control method based on rotor air extraction. This method is based on the above-mentioned radial clearance control structure and includes: Step 1: Obtain the total air temperature of the air extraction cavity 1 at the air extraction position of the compressor at different speeds, and construct a first function analysis model between the total air temperature and the speed; Step 2: According to the engine assessment condition speed, use the first function analysis model to analyze and obtain the total air temperature at the air extraction position corresponding to the assessment condition speed; Step 3. Under the engine's rated operating condition speed, test and obtain the time required to heat the rotor disk from room temperature to the preset temperature at different opening degrees of the control valve 6. Based on the rated operating condition speed and the total air temperature at the bleed air position corresponding to that speed, construct a relationship function between the rotor disk temperature and time corresponding to different opening degrees of the control valve 6 under the rated operating condition speed; In this embodiment, the relationship function between the rotor disk temperature and time corresponding to different opening degrees of the control valve 6 under the rated operating condition speed is , where is the opening degree of the control valve 6, is the total air temperature at the bleed air position under the rated operating condition speed, is the initial temperature of the rotor disk, is the preset temperature of the rotor disk, is the time required to heat the rotor disk from room temperature to the preset temperature as required by the design requirements. This relationship function takes into account various factors such as the total air temperature at the bleed air position under the engine's rated operating condition and the preheating time required by the design, and can comprehensively reflect the variation law of the rotor disk temperature with time at different opening degrees of the control valve 6, so as to achieve precise control of the preheating time of the rotor disk and the final reached temperature, in order to obtain the best rotor disk temperature control effect. Realize precise control of the radial clearance of the engine rotor. At the same time, this control method can also be combined with other engine control systems to achieve more complex control strategies to meet the working requirements of different engines.

[0024] Step 4. Based on the upper limit time required to adjust the rotor disk from room temperature to the design temperature under the rated operating condition speed, analyze and obtain the minimum opening degree of the required control valve 6 from the said relationship function.

[0025] On the basis of setting the minimum opening degree, temperature data of the compressor rotor disk or the turbine rotor disk can also be obtained by using the temperature sensing component, so as to transmit the temperature data to the controller. The controller controls the control valve 6 according to the difference between the temperature data transmitted by the temperature sensing component and the preset temperature of the corresponding compressor rotor disk or turbine rotor disk, so as to control the opening degree of the bleed air passage. For example, when the temperature detected by the temperature sensing component is much lower than the preset temperature, the controller will increase the opening degree of the control valve 6 to increase the bleed air volume, thereby increasing the temperature of the rotor disk; on the contrary, when the detected temperature is higher than the preset temperature, the controller will decrease the opening degree of the control valve 6 or completely close it to control the bleed air volume, thereby reducing the temperature of the rotor disk. It has a high degree of automation, can reduce manual intervention, and improve the efficiency of engine control.

[0026] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A radial clearance control structure based on rotor bleed air, characterized in that Comprising: An air extraction cavity, which is communicated with the inner cavity of the compressor stator casing and is used for introducing a part of the mainstream air flow of the compressor into the air extraction cavity; An air extraction passage, which is communicated with the air extraction cavity and is used for introducing the air flow in the air extraction cavity into the compressor rotor disk cavity or the turbine rotor disk cavity; A control valve, which is arranged on the air extraction passage and is used for controlling the air extraction quantity of the air extraction passage.

2. The radial clearance control structure based on rotor bleed air according to claim 1, characterized in that The control valve is an electric control valve, and the electric control valve is adjusted by a controller to control the opening degree of the air extraction passage.

3. The radial clearance control structure based on rotor bleed air according to claim 2, wherein, It further comprises a temperature sensing component, which is used for obtaining the temperature data of the compressor rotor disk or the turbine rotor disk and transmitting the temperature data to the controller, and the controller is used for controlling the control valve according to the difference between the temperature data transmitted by the temperature sensing component and the preset temperature of the corresponding compressor rotor disk or turbine rotor disk, so as to control the opening degree of the air extraction passage.

4. The radial clearance control structure based on rotor bleed air according to claim 1, wherein The air extraction passage is an air extraction pipe fixedly arranged on the compressor rotor along the radial direction; exhaust holes are arranged on the air extraction pipe, and the exhaust holes are used for introducing the mainstream gas entering the air extraction passage into the compressor disk cavity; the control valve comprises a piston arranged in the air extraction pipe, the initial radial position of the inner end face of the piston in the radial direction is located inside the exhaust hole, through holes for air flow to pass through are arranged on the piston, when the piston is in the initial position and in the cold state, the exhaust hole is completely closed, and the flow area of the exhaust hole gradually increases at a preset engine speed; a limiting component is arranged between the piston and the air inlet position of the air extraction pipe, and a compression spring is arranged between the limiting component and the outer end face of the piston in the radial direction.

5. The radial clearance control structure based on rotor bleed air according to claim 4, characterized in that The piston is of a U-shaped structure, the side wall of the piston is used for cooperating with the exhaust hole to adjust the flow area of the exhaust hole, and the through hole is arranged at the U-shaped bottom of the piston.

6. A radial clearance control method based on rotor bleed air. This method is based on the radial clearance control structure based on rotor bleed air described in any one of claims 1-3, and is characterized in that, Comprising: Obtain the total temperature of the air flow at the air extraction position of the air extraction cavity of the compressor at different speeds, and construct a first function analysis model between the total temperature of the air flow and the speed; According to the engine assessment condition speed, analyze and obtain the total temperature of the air flow at the air extraction position corresponding to the assessment condition speed by using the first function analysis model; Under the condition of the engine assessment condition speed, test and obtain the time required to heat the rotor disk from room temperature to the preset temperature at different control valve opening degrees, and construct a relationship function between the rotor disk temperature and time corresponding to different control valve opening degrees under the condition of the assessment condition speed according to the assessment condition speed and the total temperature of the air flow at the air extraction position corresponding to the speed; According to the upper limit time required to adjust the rotor disk from room temperature to the design temperature at the assessment condition speed, analyze and obtain the minimum opening degree of the control valve required on the relationship function.

7. The control method according to claim 6, wherein The relationship function between the rotor disk temperature and time corresponding to different control valve openings under the rated operating condition rotational speed is , where is the control valve opening,[[]] is the total temperature of the air flow at the air extraction position under the rated operating condition rotational speed,[[]] is the initial temperature of the rotor disk,[[]] is the preset temperature of the rotor disk,[[]] is the time required to heat the rotor disk from room temperature to the preset temperature according to the design requirements.[[]] 8. The control method according to claim 7, wherein Use the temperature sensing component to obtain the temperature data of the compressor rotor disk or the turbine rotor disk, and transmit the temperature data to the controller, and the controller controls the control valve according to the difference between the temperature data transmitted by the temperature sensing component and the preset temperature of the corresponding compressor rotor disk or turbine rotor disk, so as to control the opening degree of the air extraction passage.

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