Air supply system for core engine ground test bearing cavity sealing and adjusting method

Abstract

The invention provides an air supply system for core engine ground test bearing cavity sealing and an adjusting method.The air supply system comprises a first air entraining pipeline, a second air entraining pipeline and a support plate air supply cavity, one end of the first air entraining pipeline is communicated with a mounting base of a casing, air is entrained from the middle stage of an air compressor, and the other end of the first air entraining pipeline is communicated with the support plate air supply cavity; the other end part of the first air entraining pipeline is communicated with the support plate air supply cavity and is used for introducing high-temperature entraining air into the support plate air supply cavity; and the second air entraining pipeline is communicated with the support plate air supply cavity and used for introducing rack normal-temperature air supply into the support plate air supply cavity, the high-temperature entraining air and the rack normal-temperature air supply are mixed in the support plate air supply cavity to form bearing cavity sealing air supply, and the bearing cavity sealing air supply enters a compressor disc center through a pipeline in the support plate. The air supply temperature can be adjusted, the heat state of the air compressor is matched with the whole machine in a core machine ground test, and rack equipment does not need to have the heating capacity.

Description

Technical Field

[0001] The invention relates to the field of aviation engines, and in particular to an air supply system and an adjustment method for sealing a bearing cavity of a core engine ground test. Background Art

[0002] In the field of aircraft engine bearing cavity, the existing aircraft engine bearing cavity sealing air flow path draws air from the last stage of the supercharger stage, forms a compressor disc core flow, and then seals the rear bearing cavity. When conducting core engine ground tests, a bench air supply system is usually used to replace the last stage of the supercharger stage to achieve the sealing of the bearing cavity. The bench air supply is generally room temperature gas, which is lower than the actual state of the whole machine.

[0003] If the bench air supply system during the core engine ground test does not have the heating capacity, or the heating capacity is insufficient, the normal temperature bench air supply is used to simulate the whole machine bleed air to achieve the bearing cavity sealing. The temperature difference of the disk core flow will cause the thermal state of the compressor to be different from that of the whole machine. When conducting special thermal tests, it is impossible to simulate the actual thermal state of the whole machine rotor. This will cause the data obtained during the transition process to be biased, making it difficult to use it to correct the thermal analysis calculation model.

[0004] In view of this, the inventor of the present application has designed an air supply system and an adjustment method for sealing the bearing cavity of a core engine ground test, in order to overcome the above-mentioned technical problems. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art such as the temperature difference in the bearing cavity of an aircraft engine, which easily leads to deviations in the data obtained during the transition process, and to provide an air supply system and an adjustment method for sealing the bearing cavity of a core engine ground test.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] An air supply system for sealing a bearing cavity of a core engine ground test, characterized in that the air supply system comprises a first air bleed pipeline, a second air bleed pipeline and a support plate air supply cavity, one end of the first air bleed pipeline is connected to a mounting seat of a casing to bleed air from an intermediate stage of a compressor, and the other end of the first air bleed pipeline is connected to the support plate air supply cavity to introduce high-temperature bleed air into the support plate air supply cavity;

[0008] The second air bleed pipeline is connected to the support plate air supply cavity, and is used to introduce the normal temperature air supply of the test bench into the support plate air supply cavity. The high temperature bleed air and the normal temperature air supply of the test bench are mixed in the support plate air supply cavity to form the bearing cavity sealing air supply. The bearing cavity sealing air supply enters the compressor disc core through the pipeline in the support plate.

[0009] According to one embodiment of the present invention, the intermediate stage of the compressor includes high-pressure compressor stator blades and high-pressure compressor rotor blades that are staggered with each other.

[0010] According to an embodiment of the present invention, a first valve is provided on the first bleed air pipeline for controlling the flow rate of the high-temperature bleed air.

[0011] According to one embodiment of the present invention, a second valve is provided on the second air bleed pipeline for controlling the flow rate of the normal temperature air supply of the test bench.

[0012] According to one embodiment of the present invention, the first air duct is located on one side of the support plate air supply cavity, and the second air duct is located on the other side of the support plate air supply cavity.

[0013] According to one embodiment of the present invention, a third air bleed pipeline is provided at the bottom of the support plate air supply cavity, and the air supply of the bearing cavity seal enters the compressor disc core through the third air bleed pipeline.

[0014] The present invention also provides a method for adjusting the air supply system for sealing the bearing cavity of a core engine ground test, wherein the method adopts the air supply system for sealing the bearing cavity of a core engine ground test as described above, and the method comprises the following steps: 1 , the gas temperature T of the sealed gas in the complete engine state 109 The gas temperature T of the intermediate high-temperature bleed air 117 Satisfy a specific proportional function relationship, that is, satisfy the following formula 1:

[0015] T 109 =k 117 T 117 +b 117 ;

[0016] Among them, the proportionality coefficient k 117 and b 117 The specific value of can be obtained through performance tests and numerical calculations;

[0017] S 2 , Target flow rate of gas supply system m 109 , target temperature T 109 is a known quantity, the gas temperature T of the test bench at normal temperature 101 The valve opening on the second air flow path is adjusted to make the air flow rate m 101 Satisfies the following formula 2:

[0018]

[0019] S 3 , adjust the opening of the valve on the first bleed air path, the flow rate of the intermediate high-temperature bleed air m117 Satisfies the following formula three:

[0020] m 117 =m 109 -m 101 ;

[0021] S 4 During the core engine ground test, adjust the valve opening to meet the above-mentioned test bench normal temperature gas flow m 101 , the flow rate of the high temperature bleed air m 117 ;

[0022] Among them, m 101 The flow rate of the gas supply at normal temperature of the test bench, m 117 is the flow rate of high temperature bleed air, m 109 The air flow rate for the bearing cavity seal, T 101 The gas temperature of the test bench at normal temperature, T 117 is the gas temperature of high temperature bleed air, T 109 The temperature of the gas supplying the bearing cavity seal.

[0023] The positive and progressive effects of the present invention are:

[0024] The present invention is used for the air supply system and adjustment method for sealing the bearing cavity of the core engine ground test, which can realize the adjustable air supply temperature, so that the thermal state of the compressor is consistent with the whole machine during the core engine ground test, without the need for the bench equipment to have heating capacity. In addition, the air used for sealing the bearing cavity usually only occupies 0.2% to 0.5% of the physical flow rate of the compressor inlet, and the high-temperature mixed bleed air accounts for an even smaller proportion, so the efficiency impact of the bleed air can be ignored. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always represent the same features, wherein:

[0026] Figure 1 The figure is a schematic diagram of the air flow path of the bearing cavity seal of the core engine in the prior art.

[0027] Figure 2 It is a schematic diagram of the air supply system used for sealing the bearing cavity of the core engine ground test according to the present invention. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0029] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to represent the same or similar parts.

[0030] Furthermore, although the terms used in the present invention are selected from well-known and commonly used terms, some terms mentioned in the present invention specification may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this document.

[0031] Furthermore, it is required that the present invention be understood not only by the actual terms used but also by the meanings connoted by each term.

[0032] Figure 1 The figure is a schematic diagram of the air flow path of the bearing cavity seal of the core engine in the prior art.

[0033] like Figure 1 As described above, in the bearing cavity sealing air bleed path of the existing aircraft engine core machine, there are the bench normal temperature air supply 10, the compressor rotor 20 and the bearing cavity 30. When simulating the final stage bleed air of the supercharged stage in the whole machine state, the bench normal temperature air supply 10 passes through the flow hole of the compressor rotor 20, flows through the 1st to 5th stage disk cavity 21 of the compressor disk core, and finally reaches the rear bearing cavity 30. The pressure of the sealing gas 40 is greater than the pressure in the bearing cavity, so that the front and rear sealing of the rear bearing cavity is achieved.

[0034] Figure 2 It is a schematic diagram of the air supply system used for sealing the bearing cavity of the core engine ground test according to the present invention.

[0035] like Figure 2 As shown, the present invention discloses an air supply system for sealing the bearing cavity of a core engine ground test, which includes a first bleed air pipeline 100, a second bleed air pipeline 200 and a support plate air supply cavity 300. Among them, one end of the first bleed air pipeline 100 is connected to the mounting seat 400 of the casing to bleed air from the intermediate stage of the compressor, and the other end of the first bleed air pipeline 100 is connected to the support plate air supply cavity 300 to introduce the high-temperature bleed air 400 of the intermediate stage into the support plate air supply cavity 300. The second bleed air pipeline 200 is connected to the support plate air supply cavity 300 to introduce the bench normal temperature air supply 500 into the support plate air supply cavity 300. The high-temperature bleed air 400 of the intermediate stage and the bench normal temperature air supply 500 are mixed in the support plate air supply cavity 300 to form the bearing cavity sealing air supply 600, and the bearing cavity sealing air supply 600 enters the compressor disc through the pipeline in the support plate.

[0036] Preferably, the middle stage of the compressor includes high-pressure compressor stator blades 700 and high-pressure compressor rotor blades 800 that are staggered with each other.

[0037] Preferably, the first air bleed pipeline 100 is provided with a first valve 110 for controlling the flow of high temperature bleed air 400, that is, controlling the flow of the intermediate high temperature bleed air 400 by opening. The second air bleed pipeline 200 is provided with a second valve 210 for controlling the flow of the rack normal temperature air supply 500.

[0038] In this embodiment, the first air bleed pipeline 100 is located on one side of the support plate air supply cavity 300, and the second air bleed pipeline 200 is located on the other side of the support plate air supply cavity 300. A third air bleed pipeline 310 is provided at the bottom of the support plate air supply cavity 300, and the bearing cavity sealed air supply 600 enters the compressor disc core through the third air bleed pipeline 310.

[0039] According to the above structural description, the present invention is an air supply system for sealing the bearing cavity of a core engine ground test, in which the mounting seat 400 of the casing is connected to the first air bleed pipe 100, and air is bleed from the middle stage of the compressor. A first valve 110 is provided on the first air bleed pipe 100, and the flow rate of the high-temperature bleed air 400 is controlled by the opening degree. The high-temperature bleed air 400 is mixed with the test bench normal temperature air supply 500 in the support plate air supply cavity 300 to form the bearing cavity sealing air supply 600, which enters the compressor disc core through the pipeline in the support plate. The test bench normal temperature air supply flow path (second air bleed pipe 200) is also provided with a second valve 210 to control the flow rate.

[0040] In combination with the above structure, the present invention also provides a method for adjusting the air supply system for the core engine ground test bearing cavity sealing, which adopts the air supply system for the core engine ground test bearing cavity sealing as described above, based on the target flow m 109 , Temperature T 109 , thereby determining the valve openings on the first air bleed line and the second air bleed line, the adjustment method comprises the following steps based on the target flow rate:

[0041] Step S 1 , the gas temperature T of the sealed gas in the complete engine state 109 The gas temperature T of the intermediate high-temperature bleed air 117 Satisfy a specific proportional function relationship, that is, satisfy the following formula 1:

[0042] T 109 =k 117 T 117 +b 117 ; (Formula 1).

[0043] Among them, the proportionality coefficient k 117 and b 117 The specific value of can be obtained through performance tests and numerical calculations;

[0044] Step S 2 , Target flow rate of gas supply system m 109, target temperature T 109 is a known quantity, the gas temperature T of the test bench at normal temperature 101 The valve on the second air flow path (i.e., the second valve 210) is adjusted to open so that the flow rate m of the air supply to the rack is 101 Satisfies the following formula 2:

[0045]

[0046] Step S 3 , adjust the opening of the valve on the first bleed air path (i.e., the first valve 110), the flow rate of the intermediate high-temperature bleed air m 117 Satisfies the following formula three:

[0047] m 117 =m 109 -m 101 (Formula 3).

[0048] Step S 4 During the core engine ground test, adjust the valve opening to meet the above-mentioned test bench normal temperature gas flow m 101 , the flow rate of the high temperature bleed air m 117 .

[0049] Among them, m 101 The flow rate of the gas supply at normal temperature of the test bench, m 117 is the flow rate of high temperature bleed air, m 109 The air flow rate for the bearing cavity seal, T 101 The gas temperature of the test bench at normal temperature, T 117 is the gas temperature of high temperature bleed air, T 109 The temperature of the gas supplying the bearing cavity seal.

[0050] Through the above steps S 1 Go to step S 3 The air supply adjustment method can make the test bench air supply system match the flow and temperature state of the bearing cavity sealing air of the entire engine.

[0051] According to the above method step description, the method for adjusting the air supply system for sealing the bearing cavity of the core engine ground test of the present invention further specifically includes:

[0052] Simulate the flow rate of the bearing cavity seal air supply of the whole machine m 109 The thermal state requires that the flow rate of the bearing cavity seal air supply be kept consistent, and the flow rate of the intermediate stage high temperature bleed air m 117 and the flow rate of the normal temperature gas supply of the test bench m 101 Need to meet m 101 +m 107 =m 109 .

[0053] According to the energy equation, the gas temperature T of the bearing cavity seal gas supply 109 , the gas temperature T of the high temperature bleed air 117 , the gas temperature of the normal temperature gas supply of the test bench meets:

[0054] m 101 T 101 +m 117 T 117 =m 109 T 109 .

[0055] The gas temperature T of the normal temperature gas supply of the test bench 101 is room temperature, and the gas temperature m of the bearing cavity sealed air supply 109 and the gas temperature T of the high temperature bleed air 117 Both meet:

[0056] T 109 =k 117 T 117 +b 117 .

[0057] During the core engine ground test, according to the simulated whole machine thermal state target value T 109 and m 109 , according to the formula T 109 =k 117 T 117 +b 117 The T under the corresponding test conditions can be obtained 117 , substitute into the formula m 101 T 101 +m 117 T 117 =m 109 T 109 , we can get the flow rate m of the normal temperature gas supply of the test bench 101 , the flow rate of the high temperature bleed air m 117 :

[0058] m 117 =m 109 -m 101 .

[0059] During the core engine ground test, the valve opening is adjusted to meet the above-mentioned test bench normal temperature gas supply flow m 101 , the flow rate of the high temperature bleed air m 117 .

[0060] The present invention is used for the air supply system of the core engine ground test bearing cavity sealing. The high-temperature air is drawn from the middle stage of the compressor and mixed with the normal-temperature air supply of the test bench to achieve the purpose of simulating the bearing cavity sealing state of the whole engine (the bearing cavity sealing gas of the whole engine is much higher than the normal temperature during takeoff or cruising). The test bench air supply and air bleed section are both equipped with valves, and the air supply flow and temperature are controlled by adjusting the valve opening. At the same time, the present invention also proposes a method for adjusting the valve opening of the air supply system based on the target flow and temperature to match the flow and temperature state of the bearing cavity sealing gas of the whole engine.

[0061] In summary, the air supply system and adjustment method for sealing the bearing cavity of the core engine ground test of the present invention can realize the adjustable air supply temperature, so that the thermal state of the compressor is consistent with the whole machine during the core engine ground test, without the need for the bench equipment to have heating capabilities. Moreover, the air used for sealing the bearing cavity usually only occupies 0.2% to 0.5% of the physical flow rate of the compressor inlet, and the high-temperature mixed bleed air accounts for an even smaller proportion, so the efficiency impact of the bleed air can be ignored.

[0062] For those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary implementation of the present application.

[0063] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0064] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. An air supply system for sealing the bearing cavity of a core engine ground test, characterized in that: The air supply system includes a first bleed air pipeline, a second bleed air pipeline and a support plate air supply cavity, one end of the first bleed air pipeline is connected to the mounting seat of the casing to bleed air from the middle stage of the compressor, and the other end of the first bleed air pipeline is connected to the support plate air supply cavity to introduce high-temperature bleed air into the support plate air supply cavity; The second air bleed pipeline is connected to the support plate air supply cavity, and is used to introduce the normal temperature air supply of the test bench into the support plate air supply cavity. The high temperature bleed air and the normal temperature air supply of the test bench are mixed in the support plate air supply cavity to form the bearing cavity sealing air supply. The bearing cavity sealing air supply enters the compressor disc core through the pipeline in the support plate.

2. The air supply system for sealing the bearing cavity of a core engine ground test as claimed in claim 1, characterized in that: The middle stage of the compressor includes high-pressure compressor stator blades and high-pressure compressor rotor blades which are arranged in an interlaced manner.

3. The air supply system for sealing the bearing cavity of a core engine ground test as claimed in claim 1, characterized in that: The first bleed air pipeline is provided with a first valve for controlling the flow rate of the high-temperature bleed air.

4. The air supply system for sealing the bearing cavity of a core engine ground test as claimed in claim 1, characterized in that: The second air bleed pipeline is provided with a second valve for controlling the flow rate of the normal temperature air supply of the test bench.

5. The air supply system for sealing the bearing cavity of a core engine ground test as claimed in claim 1, characterized in that: The first air duct is located on one side of the support plate air supply cavity, and the second air duct is located on the other side of the support plate air supply cavity.

6. The air supply system for sealing the bearing cavity of a core engine ground test as claimed in claim 5, characterized in that: A third air bleed pipeline is arranged at the bottom of the support plate air supply cavity, and the air supply of the bearing cavity is sealed and enters the compressor disc core through the third air bleed pipeline.

7. A method for adjusting the air supply system for the sealing of the bearing cavity of a core engine ground test, characterized in that: The adjustment method adopts the air supply system for sealing the bearing cavity of the core engine ground test as described in any one of claims 1 to 6, and the adjustment method comprises the following steps: S1, the gas temperature T of the sealing gas in the whole engine state 109 The gas temperature T of the intermediate high-temperature bleed air 117 Satisfy a specific proportional function relationship, that is, satisfy the following formula 1: T 109 =k 117 T 117 +b 117 ; Among them, the proportionality coefficient k 117 and b 117 The specific value of can be obtained through performance tests and numerical calculations; S2, target flow rate of gas supply system m 109 , target temperature T 109 is a known quantity, the gas temperature T of the test bench at normal temperature 101 The valve opening on the second air flow path is adjusted to make the air flow rate m 101 Satisfies the following formula 2: S3, adjust the opening of the valve on the first bleed air path, the flow rate of the intermediate high-temperature bleed air m 117 Satisfies the following formula three: m 117 =m 109 -m 101 ; S4. During the core engine ground test, adjust the valve opening to meet the above-mentioned test bench normal temperature gas supply flow m 101 , the flow rate of the high temperature bleed air m 117 ; Among them, m 101 The flow rate of the gas supply at normal temperature of the test bench, m 117 is the flow rate of high temperature bleed air, m 109 The air flow rate for the bearing cavity seal, T 101 The gas temperature of the test bench at normal temperature, T 117 is the gas temperature of high temperature bleed air, T 109 The temperature of the gas supplying the bearing cavity seal.

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