An internal circulation test device and usage method for a mixed-flow turbocharger

Abstract

The present invention relates to the technical field of diesel engine mixed-flow turbochargers, and particularly relates to an in-circulation test device and a usage method for a mixed-flow turbocharger. The in-circulation test device for the mixed-flow turbocharger includes a compressor impeller, an impeller housing, a diffuser, a compressor housing, a connecting nut, and an O-ring seal; the compressor impeller has a leading edge of the main flow blade and a leading edge of the split flow blade; the impeller housing has a bypass groove, a circulation groove, and an O-ring seal groove; the test is carried out by the method of controlling variables. By changing the ratio of the distance between the circulation groove of the impeller housing and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the split flow blade, and by changing the width of the circulation groove, the in-circulation test device for the turbocharger is finally optimized, which can complete the experimental study on the effect of the in-circulation groove on broadening the surge margin of the turbocharger and solve the design deficiencies of the existing in-circulation device.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine mixed-flow turbochargers, and particularly relates to an in-circulation test device and a usage method for a mixed-flow turbocharger. Background Art

[0002] At present, in order to improve the power of diesel engines, most domestic and foreign diesel engines adopt turbocharging technology. The basic principle of turbocharging technology is that the turbine blades are driven by the exhaust gas discharged from the engine to drive the compressor impeller on the same axis to rotate. The high-speed rotating compressor impeller compresses air to achieve the purpose of increasing the intake volume of fresh air. However, while the turbocharger improves the power of the diesel engine, it will also introduce surge noise. The reason for surging is that when the flow rate is less than the design value to a certain extent, air flow separation occurs in the impeller inlet and the diffuser blades; in actual engineering applications, a circulation groove is opened on the impeller shroud of the turbocharger to achieve the effect of broadening the surge margin of the turbocharger. At present, in order to experimentally study the effect of the circulation groove opened on the impeller shroud on delaying the surge of the turbocharger, a test device is used for testing. However, when the existing test device is in use, the impeller shroud is fixed by the compressor housing. Therefore, when replacing the impeller shroud with different widths of return grooves, it is necessary to replace the impeller shroud and the compressor housing connected thereto at the same time, resulting in high test costs. Summary of the Invention

[0003] The purpose of the present invention is to provide an in-circulation test device and a usage method for a mixed-flow turbocharger, which replaces the original method of directly replacing the impeller shroud and the compressor housing to conduct tests, so that only the impeller shroud needs to be replaced during the test to achieve the purpose of studying the effect of the circulation groove opened on the impeller shroud on improving the stable working range of the turbocharger.

[0004] To achieve the above purpose, in the first aspect, the present invention provides an in-circulation test device for a mixed-flow turbocharger, including a compressor impeller, an impeller shroud, a diffuser, a compressor housing, a connecting nut, and an O-ring; the compressor impeller has a leading edge of the main flow blade and a leading edge of the split flow blade; the impeller shroud is arranged on one side of the compressor housing; the diffuser is arranged on the side of the impeller shroud; the impeller shroud has a bypass groove, a circulation groove, and an O-ring groove; the circulation groove is communicated with the bypass groove; the compressor housing is located on one side of the impeller shroud; the connecting nut is threadedly connected with the compressor housing and threadedly connected with the impeller shroud, and is located on the side of the compressor housing; the O-ring is fixedly connected with the impeller shroud and is located in the O-ring groove.

[0005] In the second aspect, the present invention also provides a usage method for an in-circulation test device for a mixed-flow turbocharger, including:

[0006] Four types of impeller housings are preset, and the ratio of the distance between the circulation groove of the four impeller housings and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the splitter blade is four ratios;

[0007] Use the four impeller housings to conduct experiments respectively to determine the optimal position of the circulation groove from the leading edge of the main flow blade;

[0008] After determining the optimal position of the circulation groove, change the width of the circulation groove and design four circulation grooves with different widths;

[0009] Conduct experiments on the four circulation grooves with different widths to select the optimal width value of the circulation groove, and finally optimize the internal circulation test device of the turbocharger.

[0010] Among them, the four ratios are 10%, 30%, 50%, and 70% respectively.

[0011] Among them, when changing the width of the circulation groove, it is based on the center line of the circulation groove and expands or shrinks on both sides of the center line of the circulation groove.

[0012] Among them, the width values of the four circulation grooves with different widths are 1.4 mm, 3.8 mm, 6.2 mm, and 8.6 mm respectively.

[0013] An internal circulation test device and a use method of a mixed-flow turbocharger according to the present invention conduct experiments by the method of controlling variables. By changing the ratio of the distance between the circulation groove of the impeller housing and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the splitter blade, and by changing the width of the circulation groove, the internal circulation test device of the turbocharger is finally optimized, and the experimental research on the effect of the internal circulation groove on widening the surge margin of the supercharger can be completed, solving the design deficiencies of the existing internal circulation device. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a schematic structural diagram of an internal circulation test device of a mixed-flow turbocharger according to the present invention.

[0016] Figure 2 It is a partial structural schematic diagram of the impeller housing and the O-ring of the present invention.

[0017] Figure 3It is a schematic structural diagram of the ratio of the distance between the circulation groove of the present invention and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the split flow blade being a ratio.

[0018] Figure 4 It is a schematic structural diagram of the ratio of the distance between the circulation groove of the present invention and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the split flow blade being b ratio.

[0019] Figure 5 It is a schematic structural diagram of the ratio of the distance between the circulation groove of the present invention and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the split flow blade being c ratio.

[0020] Figure 6 It is a schematic structural diagram of the ratio of the distance between the circulation groove of the present invention and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the split flow blade being d ratio.

[0021] Figure 7 It is a schematic structural diagram of the impeller housing of the present invention.

[0022] Figure 8 It is a flow chart of the usage method of an internal circulation test device of a mixed-flow turbocharger of the present invention.

[0023] 1 - Compressor housing, 2 - Connecting nut, 3 - Impeller housing, 4 - Bypass groove, 5 - Circulation groove, 6 - Leading edge of the main flow blade, 7 - Leading edge of the split flow blade, 8 - Diffuser, 9 - O-ring seal, 10 - Compressor impeller, 11 - O-ring seal groove. Specific embodiments

[0024] The following details the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In addition, in the description of the present invention, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0026] Please refer to Figures 1 to 8, in a first aspect, the present invention provides an in - cycle test device for a mixed - flow turbocharger, which includes a compressor impeller 10, an impeller shroud 3, a diffuser 8, a compressor housing 1, a connecting nut 2, and an O - ring seal 9; the compressor impeller 10 has a mainstream blade leading edge 6 and a splitter blade leading edge 7; the impeller shroud 3 is arranged on one side of the compressor housing 1; the diffuser 8 is arranged on the side of the impeller shroud 3; the impeller shroud 3 has a bypass groove 4, a circulation groove 5, and an O - ring seal groove 11; the circulation groove 5 communicates with the bypass groove 4; the compressor housing 1 is located on one side of the impeller shroud 3; the connecting nut 2 is threadedly connected to the compressor housing 1 and is also threadedly connected to the impeller shroud 3 and is located on the side of the compressor housing 1; the O - ring seal 9 is fixedly connected to the impeller shroud 3 and is located within the O - ring seal groove 11.

[0027] In this embodiment, the circulation groove 5 is opened at the mainstream blade leading edge 6 and the splitter blade leading edge 7 of the compressor impeller 10, and the circulation groove 5, the impeller shroud 3, and the bypass groove 4 together form an in - cycle channel; the in - cycle test device for a mixed - flow turbocharger of the present invention is divided into two parts. The first part is the compressor housing 1, which is a replacement part for each test, while the impeller shroud 3 is a fixed part and is installed only once for each test; the impeller shroud 3 with the circulation groove 5 is connected to the compressor housing 1 through the connecting nut 2. Regarding the connection method between the impeller shroud 3 as a fixed part, considering the sealing performance of the impeller shroud 3, the O - ring seal groove 11 is opened on the structure of the impeller shroud 3 as a fixed part, that is, the sealing method using the O - ring seal 9 is used to ensure the sealing performance of the connection between the impeller shrouds 3.

[0028] Specific test method: The test is carried out by the control variable method. In the first step, four impeller shrouds 3 are designed with the ratio of the distance between the circulation groove 5 and the mainstream blade leading edge 6 to the distance between the mainstream blade leading edge 6 and the splitter blade leading edge 7; in the second step, the designed four test devices are used to carry out the test. During the test, by changing the positions (a), (b), (c), and (d) of the circulation groove 5 (see Figures 3 - 6 ), the best - ratio test of the distance from the circulation groove 5 to the mainstream blade leading edge 6 accounting for the distance between the main blade leading edge and the splitter blade leading edge 7 is completed, and the best position of the circulation groove 5 from the mainstream blade leading edge 6 is determined; in the third step, after determining the best position of the circulation groove 5, keeping the center position c of the circulation groove 5 unchanged (see Figure 7 ), it is moved 1.5 mm left and right to design four width values 1e, 2e, 3e, and 4e (see Figure 7)The test device of the impeller housing 3 with the circulation groove 5 is tested respectively, and finally the best internal circulation device of the turbocharger is selected; compared with the existing internal circulation device of the turbocharger, the internal circulation test device of the mixed-flow turbocharger provided by the present invention can complete the experimental study on the effect of the internal circulation groove 5 on broadening the surge margin of the supercharger, and solve the design deficiency of the existing internal circulation device.

[0029] Secondly, the present invention also provides a method for using an internal circulation test device of a mixed-flow turbocharger, including:

[0030] S1 Four impeller housings 3 are preset, and the ratio of the distance between the circulation groove 5 of the four impeller housings 3 and the leading edge 6 of the main flow blade to the distance between the leading edge 6 of the main flow blade and the leading edge 7 of the splitter blade is four ratios;

[0031] Using the control variable method for testing, in the first step, four impeller housings 3 are designed with the ratio of the distance between the circulation groove 5 and the leading edge 6 of the main flow blade to the distance between the leading edge 6 of the main flow blade and the leading edge 7 of the splitter blade; the four ratios are 10%, 30%, 50%, and 70% respectively.

[0032] S2 The four impeller housings 3 are used respectively to conduct tests to determine the best position of the circulation groove 5 from the leading edge 6 of the main flow blade;

[0033] In the second step, the four designed test devices are used to conduct tests. During the test, by changing the positions (a), (b), (c), and (d) of the circulation groove 5 (see Figures 3 - 6 ), the best ratio test of the distance from the circulation groove 5 to the leading edge 6 of the main flow blade to the distance between the leading edge of the main blade and the leading edge 7 of the splitter blade is completed, and the best position of the circulation groove 5 from the leading edge 6 of the main flow blade is determined.

[0034] S3 After determining the best position of the circulation groove 5, change the width of the circulation groove 5, and design four different widths of the circulation groove 5;

[0035] In the third step, after determining the best position of the circulation groove 5, keeping the center position c of the circulation groove 5 (see Figure 7 ) unchanged, taking the center line of the circulation groove 5 as the reference, expand or shrink 1.5 mm on both sides of the center line of the circulation groove 5 respectively to design test devices of the impeller housing 3 with the circulation groove 5 having 4 width values 1e, 2e, 3e, and 4e (see Figure 7 ), and the width values of the four different widths of the circulation groove 5 are 1.4 mm, 3.8 mm, 6.2 mm, and 8.6 mm respectively.

[0036] S4 Conduct tests on the four different widths of the circulation groove 5 to select the best width value of the circulation groove 5, and finally select the best internal circulation test device of the turbocharger;

[0037] The best width value of the circular groove 5 is selected through tests based on the four different widths of the circular groove 5, and finally, an internal circulation test device for a turbocharger is preferably selected according to the test results.

[0038] The above-disclosed is only a preferred embodiment of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A method for using an internal circulation test device of a mixed-flow turbocharger, characterized in that it includes an internal circulation test device of a mixed-flow turbocharger, and the internal circulation test device of the mixed-flow turbocharger includes a compressor impeller, an impeller shroud, a diffuser, a compressor housing, a connecting nut and an O-ring seal; the compressor impeller has a leading edge of the main flow blade and a leading edge of the split flow blade; the impeller shroud is arranged on one side of the compressor housing; the diffuser is arranged on the side of the impeller shroud; the impeller shroud has a bypass groove, a circulation groove and an O-ring seal groove; the circulation groove is communicated with the bypass groove; the compressor housing is located on one side of the impeller shroud; the connecting nut is threadedly connected with the compressor housing and is also threadedly connected with the impeller shroud, and is located on the side of the compressor housing; the O-ring seal is fixedly connected with the impeller shroud and is located in the O-ring seal groove; the method for using the internal circulation test device of the mixed-flow turbocharger includes: presetting four impeller shrouds, and the ratio of the distance between the circulation groove and the leading edge of the main flow blade to the distance between the leading edge of the main flow blade and the leading edge of the split flow blade of the four impeller shrouds is four ratios; using the four impeller shrouds to conduct tests respectively to determine the optimal position of the circulation groove from the leading edge of the main flow blade; after determining the optimal position of the circulation groove, change the width of the circulation groove and design four circulation grooves with different widths; conduct tests on the four circulation grooves with different widths to select the optimal width value of the circulation groove, and finally optimize the internal circulation test device of the turbocharger.

2. The method for using the internal circulation test device of the mixed-flow turbocharger according to claim 1, characterized in that the four ratios are 10%, 30%, 50% and 70% respectively.

3. The method for using the internal circulation test device of the mixed-flow turbocharger according to claim 2, characterized in that when changing the width of the circulation groove, it is based on the center line of the circulation groove and expands or shrinks on both sides of the center line of the circulation groove.

4. The method for using the internal circulation test device of the mixed-flow turbocharger according to claim 3, characterized in that the width values of the four circulation grooves with different widths are 1.4 mm, 3.8 mm, 6.2 mm and 8.6 mm respectively.

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