Gas compressor test exhaust section and design method thereof

Abstract

The invention relates to the technical field of gas compressor test equipment, and particularly provides a gas compressor test exhaust section and a design method thereof. A gas compressor test exhaust section comprises a straight section used for being connected with an outlet of a gas compressor test piece; the steering section is used for connecting the straight section and the exhaust throttle valve and converting the exhaust direction from the axial direction to the radial direction, and an inner molded line and an outer molded line of a runner of the steering section are two concentric elliptic molded lines; wherein the area ratio of the outlet area to the inlet area of the steering section is a first set value, the divergence angle of an equivalent diffuser of the steering section is a second set value, so that the dimensionless stall parameter of the compression system is smaller than a set threshold value, the first set value is larger than or equal to 1.3 and smaller than or equal to 1.5, and the second set value is smaller than or equal to 5 degrees. According to the technical scheme, the safety and reliability of the gas compressor test can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of compressor test equipment, and in particular to a compressor test exhaust section and a design method thereof. Background Art

[0002] During the compressor test, the compressor test exhaust section is a key component that connects the compressor test piece with the exhaust throttling device of the test bench. Its main function is to continuously expand the airflow discharged from the compressor to ensure that the airflow can be smoothly discharged into the atmosphere. The design of the compressor test exhaust section has an important impact on the stability and safety of the compressor test.

[0003] According to the Moore-Greitzer theory of aerodynamic stability of compression systems, the size of the exhaust chamber of the compressor test will directly affect the aerodynamic instability path of the compression system. At present, most compressor test exhaust chambers adopt a large chamber design, which usually leads to aerodynamic instability of the compressor in the form of surge. Surge can cause low-frequency and high-energy pulsations of the airflow along the axial direction inside the compressor, seriously affecting the safe operation of the compressor test and even damaging the test equipment. Summary of the invention

[0004] The present disclosure is proposed in view of the above problems. The present disclosure provides a compressor test exhaust section and a design method thereof.

[0005] According to one aspect of the present disclosure, there is provided a compressor test exhaust section, comprising:

[0006] A straight section, used for connection with the outlet of the compressor test piece;

[0007] A turning section, used to connect the straight section with the exhaust throttle valve, and to change the exhaust direction from axial to radial, wherein the inner and outer mold lines of the flow channel of the turning section are two concentric elliptical mold lines;

[0008] Among them, the area ratio of the outlet area to the inlet area of ​​the turning section is a first set value, and the expansion angle of the equivalent diffuser of the turning section is a second set value, so that the dimensionless stall parameter of the compression system is less than a set threshold, wherein the first set value is greater than or equal to 1.3 and less than or equal to 1.5, and the second set value is less than or equal to 5°.

[0009] In addition, according to a compressor test exhaust section in one aspect of the present disclosure, a plurality of exhaust support plates are arranged inside the straight section, the radial dimension of the straight section is determined according to the inner and outer diameters of the compressor test piece outlet, and the axial dimension of the straight section is determined according to the chord length of the last stage stator blade of the compressor test piece and the chord length of the exhaust support plate;

[0010] The inner and outer diameters of the inlet of the turning section are equal to the inner and outer diameters of the straight section, and the outlet radius of the turning section is determined according to the radial position of the exhaust throttle valve.

[0011] In addition, according to a compressor test exhaust section according to one aspect of the present disclosure, the distance between the inlet edge of the exhaust support plate and the exhaust edge of the last stage stator blade of the compressor test piece is greater than or equal to the chord length at the average radius of the stator blade.

[0012] In addition, according to a compressor test exhaust section according to one aspect of the present disclosure, the angle between the exhaust direction of the exhaust support plate and the axial direction is smaller than a preset angle.

[0013] In addition, according to a compressor test exhaust section according to one aspect of the present disclosure, the set threshold is 0.7.

[0014] According to another aspect of the present disclosure, a design method for a compressor test exhaust section is provided, the compressor test exhaust section comprising:

[0015] A straight section, used for connection with the outlet of the compressor test piece;

[0016] A turning section, used to connect the straight section with the exhaust throttle valve, and to change the exhaust direction from axial to radial, wherein the inner and outer mold lines of the flow channel of the turning section are two concentric elliptical mold lines;

[0017] The method comprises:

[0018] Based on a preset first setting value, determining an outlet area of ​​the turning section, and determining an outlet axial length of the turning section based on the outlet area, wherein the first setting value is an area ratio of the outlet area to the inlet area of ​​the turning section, and the first setting value is greater than or equal to 1.3 and less than or equal to 1.5;

[0019] Determining an equivalent length of an equivalent diffuser of the turning section based on a preset second setting value, wherein the second setting value is a divergence angle of the equivalent diffuser of the turning section, and the second setting value is less than or equal to 5°;

[0020] Determining the axial length of the turning section based on the outlet axial length and the equivalent length;

[0021] Based on the axial length of the turning section, the cavity volume of the compressor test exhaust section is determined, and based on the cavity volume, the dimensionless stall parameter of the compression system is calculated; if the dimensionless stall parameter is greater than or equal to a set threshold, the first set value and / or the second set value is adjusted until the dimensionless stall parameter is less than the set threshold.

[0022] In addition, according to a design method of a compressor test exhaust section in one aspect of the present disclosure, a plurality of exhaust support plates are provided inside the straight section;

[0023] The method further comprises:

[0024] Determine the radial dimension of the straight section according to the inner and outer diameters of the compressor test piece outlet;

[0025] Determining the axial length of the straight section according to the chord length of the last-stage stator blade of the compressor test piece and the chord length of the exhaust support plate;

[0026] Determine the inner and outer diameters of the inlet of the turning section according to the inner and outer diameters of the straight section;

[0027] Determining the outlet radius of the turning section according to the radial position of the exhaust throttle valve;

[0028] In addition, according to a design method of a compressor test exhaust section according to one aspect of the present disclosure, the distance from the inlet edge of the exhaust support plate to the exhaust edge of the last-stage stator blade of the compressor test piece is determined based on the chord length at the average radius of the stator blade, wherein the distance between the inlet edge of the exhaust support plate and the exhaust edge of the last-stage stator blade of the compressor test piece is greater than or equal to the chord length at the average radius of the stator blade.

[0029] In addition, according to a design method for a compressor test exhaust section in one aspect of the present disclosure, the angle between the exhaust direction of the exhaust support plate and the axial direction is smaller than a preset angle.

[0030] In addition, according to a design method for a compressor test exhaust section according to one aspect of the present disclosure, the set threshold is 0.7.

[0031] According to a compressor test exhaust section and a design method thereof in an embodiment of the present disclosure, a turning section is designed with a concentric elliptical profile, and the turning section of the compressor test exhaust section utilizes the limited setting of two core design parameters, namely, area ratio and expansion angle. Under a small capacity design, the dimensionless stall parameter of the compression system can be less than a set threshold, thereby effectively controlling the stall type aerodynamic instability of the compressor, solving the aerodynamic instability problem caused by the compressor test exhaust section in the prior art, and significantly improving the safety and reliability of the compressor test.

[0032] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and other purposes, features and advantages of the present disclosure will become more apparent by describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0034] Figure 1 is a schematic diagram illustrating the structure of a compressor test exhaust section according to an embodiment of the present disclosure.

[0035] Figure 2 It is a schematic diagram of geometric parameters of the turning section in the exhaust section of the compressor test according to an embodiment of the present disclosure.

[0036] Figure 3 It is a schematic diagram of geometric parameters of an equivalent diffuser in the exhaust section of a compressor test according to an embodiment of the present disclosure.

[0037] Figure 4 is a schematic diagram of a compressor test system that further illustrates an embodiment of the present disclosure.

[0038] Figure 5 is a flow chart illustrating a method for designing a compressor test exhaust section according to an embodiment of the present disclosure.

[0039] Figure 6 It is a schematic diagram of aerodynamic instability pathway of a compressor test further illustrating an embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present disclosure more obvious, the exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described here.

[0041] See also Figure 1 to Figure 4 A compressor test exhaust section 100 includes a straight section 110 and a turning section 120 .

[0042] The straight section 110 is used to connect with the outlet of the compressor test piece 200. The straight section can be provided with a support plate to serve as a force transmission path for the compressor shaft support point, and a compressor outlet parameter test probe can be arranged inside the straight section. Figure 1 The outlet flow of the compressor test piece 200 is shown at 201 .

[0043] The turning section 120 is used to connect the straight section 110 and the exhaust throttle valve 300, and change the exhaust direction from axial to radial. The inner and outer lines of the flow channel of the turning section 120 are two concentric elliptical lines. The inner and outer lines of the flow channel of the turning section 120 are two concentric elliptical lines, which can smoothly guide the airflow to turn, reduce the risk of flow separation, and improve the aerodynamic performance.

[0044] The area ratio of the outlet area to the inlet area of ​​the turning section 120 is a first set value, and the expansion angle of the equivalent diffuser of the turning section 120 is a second set value, so that the dimensionless stall parameter of the compression system is less than the set threshold value, wherein the first set value is greater than or equal to 1.3 and less than or equal to 1.5, and the second set value is less than or equal to 5°. By reasonably selecting the area ratio and the expansion angle within the set range, the dimensionless stall parameter of the compression system is less than the set threshold value, so as to prevent the compression system from surging and ensure the stable operation of the system.

[0045] In the embodiment of the present disclosure, the inner and outer lines of the turning section 120 are two concentric elliptical lines. It can be known that the turning section 120 is used to change the exhaust direction from axial to radial. The inner and outer lines of the turning section 120 are two concentric 1 / 4 elliptical lines. That is to say, Figure 2 As shown, the inner and outer profiles of the turning section 120 are two concentric 1 / 4 elliptical profiles. This design can keep the airflow stable during the turning process, reduce flow loss, and improve aerodynamic efficiency.

[0046] In one embodiment, see Figure 1 and Figure 3 A plurality of exhaust support plates 111 are arranged inside the straight section 110. The radial dimension of the straight section 110 is determined according to the inner and outer diameters of the outlet of the compressor test piece 200, so that the flow channels are matched and the airflow disturbance caused by the interface discontinuity is reduced. The axial dimension of the straight section 110 is determined according to the chord length of the last-stage stator blade of the compressor test piece 200 and the chord length of the exhaust support plates 111, so that the exhaust support plates 111 are arranged reasonably to meet the aerodynamic and structural requirements. For example, the axial dimension L1 of the straight section 110 is C1=C2. s +C b Among them, C s Indicates the chord length of the last stage stator blade, C b represents the chord length of the exhaust support plate 111; assuming that the chord length of the last stage stator blade is C s 50mm, exhaust support plate 111 chord length C b is 70 mm, then the axial dimension of the straight section 110 is:

[0047] L1=C s +C b =50mm+70mm=120mm.

[0048] In one embodiment, see Figure 1 and Figure 3 The inlet inner and outer diameters of the turning section 120 are equal to the inner and outer diameters of the straight section 110 to maintain the continuity of the flow channel and prevent airflow separation. The outlet radius of the turning section 120 is determined according to the radial position of the exhaust throttle valve 300 at the exhaust volute 600 to enable reasonable connection with subsequent components and ensure the overall performance of the system.

[0049] In one embodiment, see Figure 1 and Figure 3 The radial dimension of the straight section 110 is determined according to the inner and outer diameters of the outlet of the compressor test piece 200. Specifically, the inner diameter and outer diameter of the radial dimension of the straight section 110 can be equal to the inner diameter and outer diameter of the outlet of the compressor test piece 200, so as to make the air flow channel size consistent and reduce the flow resistance. For example, if the outlet inner diameter of the compressor test piece 200 is 200 mm and the outer diameter is 400 mm, the inner diameter of the straight section 110 is 200 mm and the outer diameter is 400 mm.

[0050] In one embodiment, see Figure 1 and Figure 3 , the angle between the exhaust direction of the exhaust support plate 111 and the axial direction is less than the preset angle, so that the exhaust direction of the exhaust support plate 111 is close to the axial direction to maintain the stability of the airflow. For example, the angle can be set according to actual needs, usually less than 5°, for example, the angle is set to 0.5°, 1°, 3°, etc. The blade shape of the exhaust support plate 111 can adopt the NACA series standard blade shape to ensure aerodynamic performance and structural strength, or it can be customized. The exhaust support plate 111 can evenly arrange 6 exhaust support plates 111 according to the flow channel size and structural strength requirements. It should be understood that when the exhaust support plate 111 is set, when the exhaust support plate 111 is set, it is necessary to balance the load-bearing requirements and the obstruction to the airflow, and control the blockage effect of the cross-sectional area of ​​the support plate on the exhaust flow area.

[0051] In one embodiment, see Figure 1 and Figure 3 The distance D between the inlet edge of the exhaust support plate 111 and the exhaust edge of the last-stage stator blade is greater than or equal to the chord length at the average radius of the stator blade, that is, D ≥ C s This design can avoid premature disturbance of airflow at the support plate and maintain the stability of airflow.

[0052] In one embodiment, see Figure 1 and Figure 2 , the inlet inner diameter R of the turning section 120 1，inner and inlet outer diameter R 1，outer The inner and outer diameters of the straight section 110 are equal to each other to ensure the continuity of the flow channel; the outlet radius R2 is determined according to the radial position of the exhaust throttle valve 300, for example, it can be assumed to be 500 mm to match the installation position of the subsequent device, Figure 2 Reference numeral 400 is the compressor rotating shaft.

[0053] In one embodiment, see Figure 2 and Figure 3 The area ratio A2 / A1 of the outlet area A2 of the turning section 120 to the inlet area A1 is greater than or equal to 1.3 and less than or equal to 1.5. The area ratio of the outlet area A2 to the inlet area A1 of the turning section 120 and the outlet radius R2 determine the outlet axial length L2 of the turning section 120. By controlling the area ratio, the flow channel cross-section change is adjusted to prevent flow separation. The outlet area A2 of the turning section 120 is determined by the inlet area A1 and the area ratio A2 / A1. A1 is determined according to the inlet inner diameter R 1，inner and inlet outer diameter R 1，outer In the actual design process, the area ratio can be adjusted according to the size of the dimensionless stall parameter to meet the system stability requirements. For example, the area ratio can be 1.4. For details, see Figure 2 and Figure 3 The axial length L of the turning section 120 is determined according to the geometric parameters of the equivalent diffuser. The equivalent diffuser is an axisymmetric diffuser with a conical surface, and its inlet and outlet areas are respectively equal to the inlet area A1 and the outlet area A2 of the turning section 120. The angle between the generatrix of the equivalent diffuser and the compressor rotation axis 400 is the expansion angle θ of the equivalent diffuser. The equivalent length L of the equivalent diffuser is m The expansion angle θ and the equivalent radius of the inlet and outlet R 1，eff , R 2，eff It is determined that the expansion angle θ is less than or equal to 5°. Controlling the expansion angle can avoid separation caused by excessive expansion of the airflow and ensure flow stability. According to the inlet and outlet area values ​​of the equivalent diffuser, the inlet and outlet equivalent radius R of the inlet and outlet cross-section of the equivalent diffuser can be calculated. 1，eff , R 2，eff According to the trigonometric function relationship, the equivalent length L m The expansion angle θ of the equivalent diffuser and the equivalent radius R of the inlet and outlet 1，eff , R 2，eff Determine; by the equivalent length L m The axial length L of the turning section 120 can be determined by the outlet axial length L2 of the turning section 120 .

[0054] like Figure 2 As shown, the equivalent length L m The curve is the average streamline of the turning section 120. This embodiment uses a quarter ellipse instead. This approximate treatment simplifies the design and calculation while maintaining a smooth transition of the airflow. The equivalent length L m The starting point P1 and the end point P2 of the elliptical line are the coordinate midpoints of the inner and outer flow channels of the turning section 120 at the inlet and outlet sections, respectively. The radial coordinates of the starting point P1 can be calculated based on the inlet inner diameter R of the turning section 120.1，inner and inlet outer diameter R 1，outer The axial coordinate of the end point P2 can be determined according to the ellipse circumference formula. In this way, the geometric dimensions of the turning section can be accurately determined to ensure the feasibility and accuracy of the design. At this time, the axial length L of the turning section 120 can be finally determined according to the axial coordinate of the end point P2 and the outlet axial length L2 of the turning section 120.

[0055] After determining the geometric parameters of the straight section 110 and the turning section 120 , the cavity sizes of the straight section 110 and the turning section 120 are calculated respectively, and the sum of the two is the cavity size V of the compressor test exhaust section 100 .

[0056] Figure 4 Schematic diagram of the compressor test system in this embodiment, including an air intake duct, a compressor test piece 200, a compressor test exhaust section 100 and an exhaust throttling device. Compressor inlet annular flow area A c =0.203m 2 , the axial distance L from the air inlet bell mouth 500 to the outlet of the compressor test piece 200 c =3m, the volume size V of the compressor test exhaust section 100 is =0.073m 3 , the centerline speed of the compressor inlet blade at the design speed is U = 327.5m / s. According to the Moore-Greitzer compression system stability model, the dimensionless stall parameter B of the compressor test system is calculated to be 0.17, which meets the design requirement of less than 0.7 and has a large safety margin to ensure system stability.

[0057] In one embodiment, the area ratio of the outlet area to the inlet area of ​​the turning section 120 is a first set value, and the expansion angle of the equivalent diffuser of the turning section 120 is a second set value, so that the dimensionless stall parameter of the corresponding compression system is less than the set threshold. When the first set value and the second set value are determined, the area ratio and the expansion angle can be preset based on the value range of the above-mentioned area ratio and the expansion angle, and the cavity volume and the dimensionless stall parameter are calculated based on the area ratio and the expansion angle; the total cavity volume of the compressor test exhaust section 100 can be realized by using a related calculation method. After calculating the total cavity volume of the compressor test exhaust section 100, the dimensionless stall parameter B of the compression system can be calculated based on the calculated total cavity volume of the compressor test exhaust section 100 using the Moore-Greitzer model. If the B value is less than the set threshold (such as 0.7), the design meets the requirements; otherwise, the area ratio or the expansion angle is adjusted, and the calculation is recalculated until the B value is less than the set threshold. At this time, the first set value of the area ratio and the second set value of the expansion angle can be determined.

[0058] Exemplarily, the total cavity volume and the dimensionless stall parameter may be calculated as follows:

[0059] Cavity Volume and Dimensionless Stall Parameters Calculate the cavity volume (V).

[0060] Volume of the straight section 110 (V1): V1 = π × (R 2 1，outer -R 2 1，inner )×L1.

[0061] Volume (V2) of the turning section 120: the volume enclosed by the elliptical profile is calculated by integration.

[0062] Total cavity volume: V = V1 + V2.

[0063] Dimensionless stall parameter (B).

[0064] Calculation formula:

[0065]

[0066] U is the centerline velocity of the compressor inlet blades, assumed to be 300 m / s.

[0067] a is the speed of sound.

[0068] A c is the compressor inlet annular flow area, assumed to be 0.2m 2 .

[0069] L c The axial distance from the test air inlet bell mouth 500 to the outlet of the compressor test piece 200 is assumed to be 2m.

[0070] Calculation results: If B<0.7, the design meets the requirements; otherwise, the compression system will surge, adjust the first set value and / or the second set value, and recalculate the dimensionless stall parameter B value until the B value is less than 0.7.

[0071] See also Figure 1 , Figure 3 and Figure 5 A design method for a compressor test exhaust section 100, wherein the compressor test exhaust section 100 comprises a straight section 110 and a turning section 120, wherein the inner and outer mold lines of the flow passage of the turning section 120 are two concentric elliptical mold lines;

[0072] Methods include:

[0073] S501, based on a preset first set value, determine the outlet area of ​​the turning section 120, and determine the outlet axial length of the turning section 120 based on the outlet area, wherein the first set value is the area ratio of the outlet area to the inlet area of ​​the turning section 120, and the first set value is greater than or equal to 1.3 and less than or equal to 1.5.

[0074] S502: Determine an equivalent length of an equivalent diffuser of the turning section 120 based on a preset second setting value, where the second setting value is a divergence angle of the equivalent diffuser of the turning section 120, and the second setting value is less than or equal to 5.

[0075] S503: Determine the axial length of the turning section 120 based on the outlet axial length and the equivalent length.

[0076] S504, based on the axial length of the turning section 120, determine the cavity volume of the compressor test exhaust section 100, and calculate the dimensionless stall parameter of the compression system based on the cavity volume. If the dimensionless stall parameter is greater than or equal to a set threshold, adjust the first set value and / or the second set value until the dimensionless stall parameter is less than the set threshold.

[0077] In one embodiment, a plurality of exhaust support plates 111 are disposed inside the straight section 110;

[0078] The method also includes:

[0079] Determine the radial dimension of the straight section 110 according to the inner and outer diameters of the outlet of the compressor test piece 200;

[0080] The axial length of the straight section 110 is determined according to the chord length of the last-stage stator blade of the compressor test piece 200 and the chord length of the exhaust support plate 111;

[0081] According to the inner and outer diameters of the straight section 110, the inner and outer diameters of the inlet of the turning section 120 are determined;

[0082] The outlet radius of the turning section 120 is determined according to the radial position of the exhaust throttle valve 300 .

[0083] In one embodiment, the distance from the inlet edge of the exhaust support plate 111 to the exhaust edge of the last stage stator blade of the compressor test piece 200 is determined based on the chord length at the average radius of the stator blade, wherein the distance between the inlet edge of the exhaust support plate 111 and the exhaust edge of the last stage stator blade of the compressor test piece 200 is greater than or equal to the chord length at the average radius of the stator blade.

[0084] In one embodiment, the angle between the exhaust direction of the exhaust support plate 111 and the axial direction is smaller than the preset angle, so that the exhaust direction of the exhaust support plate 111 is close to the axial direction. During the design of the exhaust support plate 111, on the one hand, the strength requirements of the exhaust support plate 111 as a load-bearing component must be met; on the other hand, the blocking effect of the cross-sectional area of ​​all support plates on the exhaust flow area must be controlled.

[0085] The inner and outer contours of the turning section 120 are two concentric 1 / 4 elliptical contours; the inlet inner and outer diameters of the turning section 120 are determined according to the inner and outer diameters of the straight section 110; and the outlet radius of the turning section 120 is determined according to the radial position of the exhaust throttle valve 300.

[0086] In one embodiment, the method further includes calculating the total volume of the compressor test exhaust section 100, calculating the dimensionless stall parameter of the compression system, and if the dimensionless stall parameter is less than a set threshold, adjusting the area ratio or the expansion angle until the dimensionless stall parameter is less than the set threshold. It should be understood that the adjusted area ratio or expansion angle is within the above range, that is, the expansion angle of the equivalent diffuser of the turning section 120 is less than or equal to 5°, and the area ratio is greater than or equal to 1.3 and less than or equal to 1.5.

[0087] Finally, the compressor aerodynamic performance test is carried out to verify the design method.

[0088] Figure 6 Schematic diagram of aerodynamic instability pathway in compressor test using this embodiment.

[0089] The test carried out aerodynamic performance tests at four conversion speeds of 1.00, 0.95, 0.88 and 0.80. The aerodynamic instability path of the compressor at each conversion speed was the stall type, and no surge occurred, which verified the effectiveness of the design method, which was specifically manifested in three stages:

[0090] A) As the exhaust throttle valve 300 is closed, the compressor flow rate decreases, while the pressure ratio continues to increase to a maximum value;

[0091] B) The exhaust throttle valve 300 continues to close, the compressor flow and pressure ratio decrease rapidly, and the compressor stalls;

[0092] C) Rapidly open the exhaust throttle valve 300, and the compressor flow and pressure ratio recover. The aerodynamic performance test completes the experimental verification of the design method of the small-cavity compressor exhaust section proposed in the embodiment of the present disclosure.

[0093] In the above, with reference to the accompanying drawings, a compressor test exhaust section 100 and a design method thereof according to an embodiment of the present disclosure are described, which is intended to control the aerodynamic instability of the compressor during the test by a small cavity design. The compressor test exhaust section 100 includes a straight section 110 and a turning section 120. The straight section 110 is connected to the outlet of the compressor test piece 200, and an exhaust support plate 111 is arranged inside; the turning section 120 connects the straight section 110 and the exhaust throttle valve 300, and adopts a concentric elliptical line design. By reasonably determining the size parameters of each part, a small capacity design of the compressor test exhaust section 100 is realized, aerodynamic instability is reduced, and the test safety risk is reduced. According to a compressor test exhaust section 100 and a design method thereof according to an embodiment of the present disclosure, the area ratio of the outlet area to the inlet area of ​​the turning section 120 is set, and the expansion angle of the equivalent diffuser of the turning section 120 is set, so that under the small capacity design, the dimensionless stall parameter of the corresponding compression system is less than the set threshold, further reducing the test safety risk.

[0094] The basic principles of the present disclosure are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present disclosure. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, and are not limitations. The above details do not limit the present disclosure to the necessity of adopting the above specific details to be implemented.

[0095] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The word "such as" used here refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0096] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not mean that the example described is preferred or better than other examples.

[0097] It should also be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.

[0098] Various changes, substitutions, and modifications of the techniques described herein may be made without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of the present disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of events, means, methods, and actions described above. Currently existing or later to be developed processes, machines, manufactures, compositions of events, means, methods, or actions that perform substantially the same functions or achieve substantially the same results as the corresponding aspects described herein may be utilized. Thus, the appended claims include such processes, machines, manufactures, compositions of events, means, methods, or actions within their scope.

[0099] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0100] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A compressor test exhaust section, characterized in that: include: A straight section, used for connection with the outlet of the compressor test piece; A turning section, used to connect the straight section with the exhaust throttle valve, and to change the exhaust direction from axial to radial, wherein the inner and outer mold lines of the flow channel of the turning section are two concentric elliptical mold lines; Among them, the area ratio of the outlet area to the inlet area of ​​the turning section is a first set value, and the expansion angle of the equivalent diffuser of the turning section is a second set value, so that the dimensionless stall parameter of the compression system is less than a set threshold, wherein the first set value is greater than or equal to 1.3 and less than or equal to 1.5, and the second set value is less than or equal to 5.

2. The compressor test exhaust section according to claim 1, characterized in that: A plurality of exhaust support plates are arranged inside the straight section, the radial dimension of the straight section is determined according to the inner and outer diameters of the outlet of the compressor test piece, and the axial dimension of the straight section is determined according to the chord length of the last stage stator blade of the compressor test piece and the chord length of the exhaust support plates; The inner and outer diameters of the inlet of the turning section are equal to the inner and outer diameters of the straight section, and the outlet radius of the turning section is determined according to the radial position of the exhaust throttle valve.

3. The compressor test exhaust section according to claim 2, characterized in that: The distance between the inlet edge of the exhaust support plate and the exhaust edge of the last-stage stator blade of the compressor test piece is greater than or equal to the chord length at the average radius of the stator blade.

4. The compressor test exhaust section according to claim 2, characterized in that: The included angle between the exhaust direction of the exhaust support plate and the axial direction is smaller than the preset included angle.

5. The compressor test exhaust section according to claim 1, characterized in that: The threshold value is set to 0.

7.

6. A design method for a compressor test exhaust section, characterized in that: The compressor test exhaust section comprises: A straight section, used for connection with the outlet of the compressor test piece; A turning section, used to connect the straight section with the exhaust throttle valve, and to change the exhaust direction from axial to radial, wherein the inner and outer mold lines of the flow channel of the turning section are two concentric elliptical mold lines; The method comprises: Based on a preset first setting value, determining an outlet area of ​​the turning section, and determining an outlet axial length of the turning section based on the outlet area, wherein the first setting value is an area ratio of the outlet area to the inlet area of ​​the turning section, and the first setting value is greater than or equal to 1.3 and less than or equal to 1.5; Determining an equivalent length of an equivalent diffuser of the turning section based on a preset second setting value, wherein the second setting value is a divergence angle of the equivalent diffuser of the turning section, and the second setting value is less than or equal to 5°; Determining the axial length of the turning section based on the outlet axial length and the equivalent length; Based on the axial length of the turning section, the cavity volume of the compressor test exhaust section is determined, and based on the cavity volume, the dimensionless stall parameter of the compression system is calculated; if the dimensionless stall parameter is greater than or equal to a set threshold, the first set value and / or the second set value is adjusted until the dimensionless stall parameter is less than the set threshold.

7. The method according to claim 6, characterized in that A plurality of exhaust support plates are arranged inside the straight section; The method further comprises: Determine the radial dimension of the straight section according to the inner and outer diameters of the compressor test piece outlet; Determining the axial length of the straight section according to the chord length of the last-stage stator blade of the compressor test piece and the chord length of the exhaust support plate; Determine the inner and outer diameters of the inlet of the turning section according to the inner and outer diameters of the straight section; The outlet radius of the turning section is determined according to the radial position of the exhaust throttle valve.

8. The method according to claim 7, characterized in that According to the chord length at the average radius of the stator blades, the distance from the inlet edge of the exhaust support plate to the exhaust edge of the last stage stator blades of the compressor test piece is determined, wherein the distance between the inlet edge of the exhaust support plate and the exhaust edge of the last stage stator blades of the compressor test piece is greater than or equal to the chord length at the average radius of the stator blades.

9. The method according to claim 7, characterized in that: The included angle between the exhaust direction of the exhaust support plate and the axial direction is smaller than the preset included angle.

10. The method according to claim 6, characterized in that The threshold value is set to 0.7.

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