Adaptive bleed air adjustment structure and design method for multi-operating radial clearance of compressor

Abstract

The present invention relates to the field of compressors and bleed air flow path design thereof, and discloses an adaptive bleed air adjustment structure and design method for a multi-operating-condition radial clearance of a compressor. The structure utilizes the pressure change of the compressor rear stage at different compressor speeds to adaptively adjust the bleed air valve position, thereby adaptively adjusting the bleed air flow in a first bleed air cavity at different speeds to heat the compressor disc cavity without the need for pilot operation. The bleed air structure is simple and has little effect on the dynamic characteristics of the compressor rotor. In addition, an analytical model between the control cavity pressure and the speed is constructed to determine the valve control cavity pressure corresponding to different speeds. Under the condition of considering the valve structural parameters, the valve opening timing is controlled and it is ensured that the valve is fully opened at a preset speed, thereby achieving heating of the compressor disc cavity with a maximum bleed air flow through the first bleed air channel at the preset speed.

Description

Technical Field

[0001] The invention relates to the field of compressor and bleed air flow path design thereof, and discloses a self-adaptive bleed air adjustment structure and a design method for a multi-working-condition radial clearance of a compressor. Background Art

[0002] As a core component of an aircraft engine, the high-pressure compressor's primary function is to transmit mechanical energy to the gas, completing the gas compression process in the engine's thermodynamic cycle to increase gas pressure. Its performance has a significant impact on the entire engine. The high-pressure compressor provides the majority of the cycle's pressure ratio, and its load, efficiency, and stable operating margin directly impact the engine's overall fuel consumption, operating range, and reliability.

[0003] The radial clearance between the rotor and stator of a high-pressure compressor is a crucial factor in the compressor's aerodynamic performance, stability, and operational reliability. However, to ensure safe and reliable operation of aircraft compressors under various operating conditions, the radial clearance between the compressor rotor and the corresponding casing is traditionally designed for the most demanding operating conditions. This results in the high-pressure compressor having a small radial clearance only under certain critical operating conditions, while the radial clearance is larger under other operating conditions. This seriously affects the aerodynamic performance and operating margin of the high-pressure compressor under low operating conditions.

[0004] Research shows that the main reason for the radial differences in different working conditions of the compressor is that the different pressures and thermal loads on the rotor and stator of the compressor lead to large deformation differences. The existing compressor and its air flow path design cannot realize the active control method of the radial clearance of the high-pressure compressor. Summary of the Invention

[0005] The purpose of the present invention is to provide an adaptive bleed air adjustment structure and design method for the multi-operating-condition radial clearance of a compressor, which can realize adaptive adjustment of the bleed air flow in the first bleed air cavity at different speeds to heat the compressor disc cavity.

[0006] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0007] The adaptive bleed air adjustment structure for the multi-operating-condition radial clearance of the compressor includes:

[0008] a first bleed air cavity, the first bleed air cavity being in communication with the inner cavity of the compressor stator casing and being used for introducing the airflow of the compressor intermediate stage into the first bleed air cavity;

[0009] a first air bleed channel, connected to the first air bleed cavity, for guiding the air flow in the first air bleed cavity into the compressor disc cavity;

[0010] A valve, the valve being arranged on the first air inlet passage, the valve comprising a control chamber, an adjusting rod being arranged in the control chamber, and a return spring being arranged on the adjusting rod and abutting against an inner wall of the valve chamber;

[0011] a second bleed air cavity, the second bleed air cavity being in communication with the inner cavity of the compressor stator casing and being used for introducing airflow from a rear stage of the compressor into the second bleed air cavity, the rear stage being a compressor-stator stage downstream of the compressor intermediate stage;

[0012] A second air bleed channel, one end of the second air bleed channel is connected to the second air bleed chamber, and the other end of the second air bleed channel is connected to the control chamber of the valve, for introducing the airflow in the second air bleed chamber into the control chamber, so as to adjust the relative position of the adjustment rod according to the relative size of the pressure in the second air bleed chamber and the elastic force of the return spring, so as to control the flow area of the first air bleed channel at the valve.

[0013] Furthermore, when the initial position of the regulating rod is in a cold state, the first bleed air passage is in a fully open state, and when the compressor speed increases to a preset speed, the flow area of the valve gradually decreases.

[0014] Furthermore, when the initial position of the regulating rod is in a cold state, the first bleed air passage is in a completely closed state, and when the compressor speed increases to a preset speed, the flow area of the valve gradually increases.

[0015] To achieve the above technical effects, the present invention further provides a design method for an adaptive bleed air adjustment structure for a multi-operating-condition radial clearance of a compressor, which is used to obtain a design range of spring coefficients required for a return spring of the adaptive bleed air adjustment structure for a multi-operating-condition radial clearance of a compressor, including:

[0016] Obtaining a static pressure value of the second bleed air chamber at the bleed air position of the rear stage of the compressor at the test speed, as well as a cavity pressure of the control chamber during the bleed air process; and analyzing and obtaining a pressure loss coefficient of the second bleed air passage based on the static pressure value at the test speed and the cavity pressure of the control chamber during the bleed air process at the test speed;

[0017] Obtaining static pressure values of the second bleed air cavity at the bleed air position of the rear stage of the compressor at different speeds of the compressor, and constructing a first functional relationship model between the static pressure value and the speed data value;

[0018] Constructing a second functional relationship model between the cavity pressure of the control cavity and the rotational speed data value based on the first functional relationship model and the pressure loss coefficient of the second air induction channel obtained by analysis;

[0019] The control chamber pressure of the compressor at a preset speed is calculated using the second functional relationship model;

[0020] The upper limit of the spring constant of the rebound spring is obtained by analysis based on the effective area of the airflow in the control chamber on the adjustment rod, the control chamber pressure corresponding to the preset speed, and the minimum displacement length of the adjustment rod relative to the initial position of the adjustment rod when the first air inlet channel is fully opened or fully closed.

[0021] Furthermore, the pressure loss coefficient of the second air inlet passage is calculated according to The analysis obtained is the pressure loss coefficient of the second air bleed channel, is the cavity pressure of the control cavity at the test speed, It is the static pressure value of the second bleed air cavity at the bleed air position of the rear stage of the compressor at the test speed.

[0022] Furthermore, the second functional relationship model between the cavity pressure and the rotation speed of the control cavity is: ,in is a first functional relationship model between the static pressure value and the speed data value.

[0023] Furthermore, the upper limit of the spring rate of the rebound spring is ,in The control chamber pressure corresponding to the preset compressor speed is In order to control the effective action area of the airflow in the cavity on the regulating rod, It is the minimum displacement length of the adjustment rod relative to the initial position of the adjustment rod when the first air induction channel is fully opened or fully closed.

[0024] Furthermore, when the initial position of the regulating rod is in a cold state, the first bleed air passage is in a fully open state, and when the compressor speed increases to a preset speed, the flow area of the valve gradually decreases.

[0025] Compared with the prior art, the present invention has the following beneficial effects: the present invention utilizes the pressure changes of the compressor rear stage at different compressor speeds to adaptively adjust the position of the bleed air valve, thereby realizing adaptive adjustment of the bleed air flow in the first bleed air cavity at different speeds to heat the compressor disc cavity without the need for pilot operation; and the bleed air structure is simple, highly reliable, and has low weight cost; the components are all stator parts, which have little impact on the dynamic characteristics of the compressor rotor and have low safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the adaptive bleed air adjustment structure of the multi-operating-condition radial clearance of the compressor in the embodiment;

[0027] Among them, 1. First air bleed cavity; 2. Stator casing; 3. First air bleed channel; 4. Compressor disc cavity; 5. Control cavity; 6. Adjustment rod; 7. Return spring; 8. Second air bleed cavity; 9. Second air bleed channel. DETAILED DESCRIPTION

[0028] The present invention will be described in further detail below with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the present invention to the following embodiments, as all technologies implemented based on the present invention fall within the scope of the present invention.

[0029] Example

[0030] See also Figure 1 The adaptive bleed air adjustment structure for the multi-operating radial clearance of the compressor includes:

[0031] A first bleed air cavity 1, which is in communication with the inner cavity of the compressor stator casing 2 and is used to introduce the airflow of the compressor intermediate stage into the first bleed air cavity 1;

[0032] A first air bleed channel 3, connected to the first air bleed cavity 1, for guiding the air flow in the first air bleed cavity 1 to the compressor disc cavity 4;

[0033] A valve, the valve being provided on the first air inlet passage 3, the valve comprising a control chamber 5, an adjusting rod 6 being provided in the control chamber 5, and a return spring 7 being provided on the adjusting rod 6 and abutting against the inner wall of the valve chamber;

[0034] a second bleed air cavity 8, the second bleed air cavity 8 being in communication with the inner cavity of the compressor stator casing 2 and being used for introducing airflow from the rear stage of the compressor into the second bleed air cavity 8, the rear stage being the compressor-stator stage downstream of the compressor intermediate stage;

[0035] The second air bleed channel 9, one end of the second air bleed channel 9 is connected to the second air bleed chamber 8, and the other end of the second air bleed channel 9 is connected to the control chamber 5 of the valve, and is used to introduce the airflow in the second air bleed chamber 8 into the control chamber 5, so as to adjust the relative position of the adjusting rod 6 according to the relative size of the pressure in the second air bleed chamber 8 and the elastic force of the return spring 7, so as to control the flow area of the first air bleed channel 3 at the valve.

[0036] In this embodiment, the bleed air pressure of the rear stage and the intermediate stage varies with the rotational speed during the operation of the compressor. The bleed air valve position is adaptively adjusted by utilizing the pressure variation of the rear stage of the compressor at different compressor rotational speeds, so that the bleed air flow in the first bleed air cavity 1 is adaptively adjusted at different rotational speeds to heat the compressor disc cavity 4, effectively accelerating the engine warm-up speed without the need for pilot operation. The bleed air structure is simple, highly reliable, and has a low weight cost. All components are stator parts, which have little impact on the dynamic characteristics of the compressor rotor and a low safety risk.

[0037] In this embodiment, by setting the initial position of the adjustment lever 6 to fully open the first bleed air passage 3 when the compressor is cold, the valve's flow area gradually decreases as the compressor speed increases to a predetermined speed. This effectively accelerates the temperature rise of the engine rotor components at low compressor speeds and controls the range of the transitional clearance. At high speeds, the valve's flow area decreases, reducing the airflow in the compressor disc cavity 4 and improving engine efficiency.

[0038] In some embodiments, when the initial position of the adjusting rod 6 is in a cold state, the first air inlet channel 3 is in a completely closed state. During the process of the compressor speed increasing to a preset speed, the flow area of the valve gradually increases. It can be realized as needed that during the operation of the compressor, the flow area of the valve is small at low speed, and the flow area of the valve is increased at high speed.

[0039] Based on the same inventive concept, this embodiment further provides a design method for an adaptive bleed air adjustment structure for a compressor with multi-operating-condition radial clearance, which is used to obtain a design range value of a spring coefficient required for the return spring 7 of the adaptive bleed air adjustment structure for a compressor with multi-operating-condition radial clearance, including:

[0040] Step 1: Obtain the static pressure value of the second bleed air chamber 8 at the bleed air position of the compressor's rear stage at the test speed, as well as the cavity pressure of the control chamber 5 during the bleed air process; and analyze and obtain the pressure loss coefficient of the second bleed air channel 9 based on the static pressure value at the test speed and the cavity pressure of the control chamber 5 during the bleed air process at the test speed.

[0041] In this embodiment, the pressure loss coefficient of the second air inlet passage 9 is based on The analysis obtained is the pressure loss coefficient of the second air inlet passage 9, To control the cavity pressure of cavity 5 at the test speed, It is the static pressure value of the second bleed air cavity 8 at the bleed air position of the rear stage of the compressor at the test speed.

[0042] Step 2: Obtain the static pressure value of the second bleed air cavity 8 at the bleed air position of the rear stage of the compressor at different speeds of the compressor, and construct a first functional relationship model between the static pressure value and the speed data value.

[0043] Step 3: constructing a second functional relationship model between the cavity pressure of the control cavity 5 and the rotational speed data value based on the first functional relationship model and the pressure loss coefficient of the second air induction channel 9 obtained by analysis;

[0044] In this embodiment, the second functional relationship model between the cavity pressure and the rotation speed of the control cavity 5 is: ,in is a first functional relationship model between the static pressure value and the speed data value.

[0045] Step 4: Using the second functional relationship model, calculate the pressure of the control chamber 5 of the compressor at a preset speed;

[0046] Step 5: Analyze and obtain the upper limit of the spring constant of the rebound spring 7 based on the effective area of the airflow in the control chamber 5 on the adjustment rod 6, the pressure of the control chamber 5 corresponding to the preset speed, and the minimum displacement length of the adjustment rod 6 relative to the initial position of the adjustment rod 6 when the first air inlet channel 3 is fully opened or fully closed;

[0047] In this embodiment, the upper limit value of the stiffness coefficient of the rebound spring 7 is ,in The pressure of control chamber 5 corresponding to the preset speed of the compressor, In order to control the effective action area of the airflow in the cavity 5 on the regulating rod 6, It is the minimum displacement length of the adjustment rod 6 relative to the initial position of the adjustment rod 6 when the first air inlet channel 3 is fully opened or fully closed.

[0048] In this embodiment, an analytical model between the cavity pressure of the control cavity 5 and the rotational speed is constructed to determine the cavity pressure of the valve control cavity 5 corresponding to different rotational speeds. Taking into account the valve structural parameters, the valve opening timing is controlled and it is ensured that the valve is fully opened at a preset rotational speed, thereby achieving heating of the compressor disc cavity 4 with the maximum amount of bleed air through the first bleed air channel 3 at the preset rotational speed.

[0049] It should be noted that the preset speed can be either high or low. For example, to effectively accelerate the temperature rise of the engine rotor components at low speed during compressor operation and control the range of transitional clearance variation, while reducing the valve flow area at high speed to reduce the airflow in the compressor disc cavity 4 and improve engine efficiency, the initial position of the regulating rod 6 can be set to the fully open state of the first bleed passage 3 when the compressor speed increases to the preset speed, so that the valve flow area gradually decreases.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. The adaptive bleed air adjustment structure for the multi-operating radial clearance of the compressor is characterized by: include: a first bleed air cavity, the first bleed air cavity being in communication with the inner cavity of the compressor stator casing and being used for introducing the airflow of the compressor intermediate stage into the first bleed air cavity; a first air bleed channel, connected to the first air bleed cavity, for guiding the air flow in the first air bleed cavity into the compressor disc cavity; A valve, the valve being arranged on the first air inlet passage, the valve comprising a control chamber, an adjusting rod being arranged in the control chamber, and a return spring being arranged on the adjusting rod and abutting against an inner wall of the valve chamber; a second bleed air cavity, the second bleed air cavity being in communication with the inner cavity of the compressor stator casing and being used for introducing airflow from a rear stage of the compressor into the second bleed air cavity, the rear stage being a compressor-stator stage downstream of the compressor intermediate stage; A second air bleed channel, one end of the second air bleed channel is connected to the second air bleed chamber, and the other end of the second air bleed channel is connected to the control chamber of the valve, for introducing the airflow in the second air bleed chamber into the control chamber, so as to adjust the relative position of the adjustment rod according to the relative size of the pressure in the second air bleed chamber and the elastic force of the return spring, so as to control the flow area of the first air bleed channel at the valve.

2. The adaptive bleed air adjustment structure for multi-operating-state radial clearance of a compressor according to claim 1, characterized in that: When the initial position of the regulating rod is in a cold state, the first bleed air passage is in a fully open state. During the process of the compressor speed increasing to a preset speed, the flow area of the valve gradually decreases.

3. The adaptive bleed air adjustment structure for multi-operating-state radial clearance of a compressor according to claim 1, characterized in that: When the initial position of the regulating rod is in a cold state, the first bleed air passage is in a completely closed state. During the process of the compressor speed increasing to a preset speed, the flow area of the valve gradually increases.

4. A method for designing an adaptive bleed air adjustment structure for a multi-operating radial clearance of a compressor, for obtaining a design range value of a spring coefficient required for a return spring of the adaptive bleed air adjustment structure for a multi-operating radial clearance of a compressor as claimed in claim 1, characterized in that: include: Obtaining the static pressure value of the second bleed air cavity at the bleed air position of the rear stage of the compressor at the test speed of the compressor, and the cavity pressure of the control cavity during the bleed air process; The pressure loss coefficient of the second air bleed channel is obtained by analysis based on the static pressure value at the test speed and the cavity pressure of the control cavity during the air bleed process at the test speed; Obtaining static pressure values of the second bleed air cavity at the bleed air position of the rear stage of the compressor at different speeds of the compressor, and constructing a first functional relationship model between the static pressure value and the speed data value; Constructing a second functional relationship model between the cavity pressure of the control cavity and the rotational speed data value based on the first functional relationship model and the pressure loss coefficient of the second air induction channel obtained by analysis; The control chamber pressure of the compressor at a preset speed is calculated using the second functional relationship model; The upper limit of the spring constant of the rebound spring is obtained by analysis based on the effective area of the airflow in the control chamber on the adjustment rod, the control chamber pressure corresponding to the preset speed, and the minimum displacement length of the adjustment rod relative to the initial position of the adjustment rod when the first air inlet channel is fully opened or fully closed.

5. The design method according to claim 4, characterized in that: The pressure loss coefficient of the second air bleed passage is calculated based on The analysis obtained is the pressure loss coefficient of the second air bleed channel, is the cavity pressure of the control cavity at the test speed, It is the static pressure value of the second bleed air cavity at the bleed air position of the rear stage of the compressor at the test speed.

6. The design method according to claim 4, characterized in that: The second functional relationship model between the cavity pressure and the rotation speed of the control cavity is: ,in is a first functional relationship model between the static pressure value and the speed data value.

7. The design method according to claim 4, characterized in that: Upper limit of spring rate of rebound spring ,in The control chamber pressure corresponding to the preset compressor speed is In order to control the effective action area of the airflow in the cavity on the regulating rod, It is the minimum displacement length of the adjustment rod relative to the initial position of the adjustment rod when the first air induction channel is fully opened or fully closed.

8. The design method according to claim 7, characterized in that: When the initial position of the regulating rod is in a cold state, the first bleed air passage is in a fully open state. During the process of the compressor speed increasing to a preset speed, the flow area of the valve gradually decreases.

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