Three-dimensional impeller with adaptive variable attack angle for centrifugal compressor and working method thereof

Abstract

The present invention relates to a three-dimensional impeller with an adaptive variable attack angle for a centrifugal compressor and a working method thereof, characterized in that: the three-dimensional impeller structure includes an impeller and a blade hood provided on the inlet end of multiple blades of the impeller and capable of rotating to change the blade inlet installation angle; the blade hood is provided with a first elastic clamp petal and a second elastic clamp petal that abut the surface of the impeller blade inlet end, the air inlet side of the blade hood is in a pointed cone shape, the end of the blade hood is connected to a gear shaft, and the impeller is provided with a driving mechanism for driving the gear shaft to rotate. This patent enables the impeller attack angle to be maintained within a smaller range when the compressor is operated under conditions deviating from the design operating conditions. It not only has the characteristics of fast adjustment speed and high reliability, but also can broaden the operating range of the compressor and improve the efficiency of the compressor.

Description

Technical Field

[0001] The invention relates to a three-dimensional impeller with adaptive variable attack angle for a centrifugal compressor and a working method thereof. Background Art

[0002] Centrifugal compressors are widely used gas boosting equipment in the industrial field. Their aerodynamic performance is directly related to the energy efficiency level of application systems such as energy, chemical industry, and power. The impeller is the only component of the compressor that does work on the gas. It is responsible for converting the input mechanical energy into gas pressure energy and kinetic energy. Therefore, improving the efficiency of the impeller has always been a research hotspot. The impeller blade inlet installation angle is the key geometric constraint for the closure of the impeller inlet velocity triangle. It directly determines the angle of attack of the airflow entering the impeller flow channel and has a significant impact on the impeller efficiency, noise, and stable operating range. This geometric-aerodynamic coupling characteristic determines that the impeller not only needs to ensure that the angle of attack is close to zero at the design point to obtain smaller impact losses, but also needs to maintain a reasonable angle of attack when deviating from the design operating conditions to avoid larger flow losses.

[0003] Conventional impellers generally adopt a fixed impeller blade inlet installation angle design. This geometric parameter becomes an unadjustable fixed structural parameter after the impeller is machined and formed. Since the impeller angle of attack is defined as the difference between the impeller blade inlet installation angle and the impeller blade inlet airflow angle, the limitation is that when the compressor deviates from the design operating conditions, the gas flow direction and the impeller blade inlet installation angle will produce an uncontrollable angle of attack deviation. Specifically, under high flow conditions, a negative angle of attack is formed, resulting in increased suction surface flow separation and increased boundary layer losses; under low flow conditions, a positive angle of attack occurs, inducing pressure surface flow stall, resulting in a sharp drop in efficiency and the risk of instability. This fixed geometric constraint makes conventional impellers always face problems such as poor adaptability to working conditions and a narrow high-efficiency zone, which seriously restricts the overall performance improvement of the compressor.

[0004] In applications such as hydrogen fuel cell stacks, refrigeration compressors, and turbochargers, compressors must frequently switch between rated flow, low flow, and high flow conditions. Conventional impeller compressors exhibit poor performance in these conditions, hindering system transient response and efficient operation over a wide range of operating conditions. Currently, existing optimization techniques typically adjust the impeller blade profile to improve compressor performance under specific operating conditions, but these techniques cannot fundamentally address the aerodynamic matching issue within a specific operating range. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide an adaptive variable-angle three-dimensional impeller structure and a working method thereof for a centrifugal compressor. The impeller can adjust the impeller blade inlet installation angle according to the rotational speed, so that when the compressor operates under conditions deviating from the design operating conditions, the impeller angle of attack can still be maintained within a smaller range. It not only has the characteristics of fast adjustment speed and high reliability, but also can broaden the operating range of the compressor and improve the efficiency of the compressor.

[0006] The three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor of the present invention is characterized in that it includes an impeller and a blade hood provided on the inlet end of multiple blades of the impeller and capable of rotating to change the blade inlet installation angle; the blade hood has a first elastic clamp petal and a second elastic clamp petal that are in contact with the surface of the impeller blade inlet end, the air inlet side of the blade hood is in a pointed cone shape, the end of the blade hood is connected to a gear shaft, and the impeller is provided with a driving mechanism for driving the gear shaft to rotate.

[0007] Preferably, the driving mechanism is a rack driven by centrifugal force, and the rack is meshed with the gear end of the gear shaft for transmission.

[0008] Preferably, the blade hood is provided with a countersunk hole along its length direction for interference fit and plugging the gear shaft end, the central part of the impeller is provided with an impeller top shaft hole, and the hole wall of the impeller top shaft hole is evenly provided with a plurality of middle square grooves corresponding to the blade hood, and the bottom of the middle square groove is provided with a shaft hole for passing the gear shaft end, and the gear end of the gear shaft extends into the middle square groove and engages with the rack located in the middle square groove for transmission; the bottom surface of the impeller is evenly provided with a plurality of T-slots and a driving slider slidably connected to the T-slot, and the driving slider drives the rack to move through an intermediate connecting piece, so that when the impeller runs at high speed, the centrifugal force drives the slider to move away from the center of the impeller, and the gear shaft and the blade hood are driven to rotate by the intermediate connecting piece and the rack, thereby changing the blade inlet installation angle.

[0009] Preferably, a return spring is installed in the above-mentioned T-slot, one end of the return spring abuts the end of the T-slot at the bottom of the impeller, and the other end of the return spring is connected to the lifting ring on the driving slider, the driving slider hinge support on the driving slider is hinged to one end of the driving slider connecting rod, and the other end of the driving slider connecting rod is hinged to the long end of the double-headed crank of the double-headed crank, and the double-headed crank rotation center is rotatably connected to the double-headed crank hinge support, and the double-headed crank hinge support is fixed to the impeller, and the short end of the double-headed crank is hinged to one end of the slider-rack integrated part connecting rod, and the other end of the slider-rack integrated part connecting rod is hinged to the lower end of the slider-rack integrated part, and the upper part of the slider-rack integrated part is provided with the rack, and the driving slider connecting rod, the double-headed crank, the slider-rack integrated part connecting rod and the slider-rack integrated part constitute an intermediate connecting part.

[0010] Preferably, the setting direction of the above-mentioned T-slot is consistent with the direction of the blade inlet tip pointing to the blade root, and an impeller bottom cavity is provided above the bottom of the impeller to accommodate the movement of the driving slider connecting rod and the double-headed crank, and a mounting hole for installing the double-headed crank hinge support is provided on the wall surface of the impeller bottom cavity; the T-slot of the impeller, the impeller bottom cavity, the middle square groove and the shaft hole are evenly arranged in several groups along the circumference.

[0011] Preferably, the above-mentioned blade hood has a torsion angle along the axial direction of the gear shaft, and the torsion angle value is consistent with the angle change value from the blade inlet root to the blade tip, so that the first elastic clamp petal and the second elastic clamp petal of the blade hood can fit tightly on the blade inlet end surface.

[0012] Preferably, the slider rack integrated part comprises a slider rack integrated part hinge support, a vertical square rod, a horizontal rod and a rack connected in sequence, and a support spring is provided between the end bottom of the horizontal rod and the middle square groove.

[0013] Preferably, the double-ended crank has two straight rod sections, which are bent relative to each other to form an obtuse angle, and the bending point is located at the rotation center of the double-ended crank.

[0014] Preferably, a gear washer composed of two halves is coaxially sleeved on the shaft end of the gear shaft near the gear end, and the gear washer is used to cushion the gear shaft to ensure the meshing of the gear end and the rack.

[0015] The present invention provides a working method for a three-dimensional impeller structure with an adaptive variable attack angle for a centrifugal compressor. When the impeller speed increases, the driving slider moves linearly in the T-slot toward a position away from the impeller axis and drives the driving slider connecting rod, the double-headed crank, the slider-rack integrated part connecting rod and the slider-rack integrated part to move, thereby causing the rack on the slider-rack integrated part to drive the gear end of the gear shaft and the blade hood to rotate, changing the impeller blade inlet installation angle, thereby achieving the purpose of reducing the attack angle and improving the efficiency of the compressor.

[0016] The beneficial effects of the patent of the present invention are: fast adjustment speed, high reliability, and simple structure, which are conducive to broadening the operating range of the compressor and improving the aerodynamic performance of the compressor; the impeller blade inlet installation angle can be automatically adjusted within the operating range higher than the impeller design speed to reduce the angle of attack, thereby reducing flow loss; the driving slider can drive the entire transmission system to quickly respond to changes in the impeller speed, so that the impeller blade inlet installation angle always maintains a better angle; the overall structure adopts a purely mechanical structure and does not contain electronic components inside, so it has high reliability and relatively low cost; and the blade hood can be used to quickly test the performance of different blade leading edge geometries, which is beneficial to the research and development and design of new models; through the above method, the operating range of the compressor under high speed and large flow conditions can be increased, and the aerodynamic efficiency of the area can be improved; at the same time, it helps to reduce the power consumption of the compressor and accelerate the research and development and design of new blade leading edge geometries. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings;

[0018] Figure 1 It is a schematic diagram of the top view of the structure of the present invention;

[0019] Figure 2 AA cross-sectional structural schematic diagram of the present invention;

[0020] Figure 3 It is a schematic diagram of the BB cross-sectional structure of the present invention;

[0021] Figure 4 is a bottom perspective view of the present invention;

[0022] Figure 5 yes Figure 4 Enlarged view of the middle K section;

[0023] Figure 6 This is a three-dimensional diagram of the connection structure between the gear shaft and the blade cap;

[0024] Figure 7 yes Figure 6 The main view;

[0025] Figure 8 yes Figure 2 A partial view of

[0026] Figure 9 yes Figure 3 A partial view of

[0027] Figure 10 yes Figure 1 A partial view of

[0028] Figure 11 It is a three-dimensional diagram of the driving slider;

[0029] Figure 12 It is a three-dimensional diagram of the connecting rod driving the slider;

[0030] Figure 13 It is a three-dimensional diagram of a double-ended crank;

[0031] Figure 14 It is a three-dimensional diagram of a double-ended crank hinge support;

[0032] Figure 15 It is a three-dimensional diagram of the connecting rod of the slider rack integrated part;

[0033] Figure 16 It is a three-dimensional diagram of the slider rack integrated part;

[0034] Figure 17 This is a three-dimensional diagram of the location of the shaft hole at the top of the impeller;

[0035] Figure 18 It is a three-dimensional image in the central square groove;

[0036] Figure 19 It is a three-dimensional diagram of the connection of intermediate connectors, etc.

[0037] Markings: 1. Impeller; 2. Return spring; 3. Drive slider; 4. Drive slider connecting rod; 5. Double crank; 6. Double crank hinge support; 7. Screw; 8. Slider rack integral part connecting rod; 9. Slider rack integral part; 10. Support spring; 11. Gear shaft; 12. Gear gasket; 13. Blade cap; 31. Lifting ring; 32. Drive slider hinge support; 33. Rail holding boss; 51. Double crank long end; 52. Double crank rotation center; 53. Double crank short end; 91 , slider rack integrated hinge support; 92, vertical square rod; 93, horizontal rod; 94, rack; 101, end of T-slot at the bottom of impeller; 102, T-slot; 103, cavity at the bottom of impeller; 104, middle square groove; 105, shaft hole at the top of impeller; 106, boss at the bottom of impeller; 107, shaft hole; 108, mounting hole; 1101, gear end; 1102, shaft end; 1301, root of blade hood; 1302, top of blade hood; 1303, first elastic clamp petal; 1304, second elastic clamp petal. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0039] As shown in the figure, the three-dimensional impeller structure with adaptive variable attack angle for the centrifugal compressor of the present invention includes an impeller 1, a return spring 2, a driving slider 3, a driving slider connecting rod 4, a double-headed crank 5, a double-headed crank hinge support 6, a screw 7, a slider rack integrated part connecting rod 8, a slider rack integrated part 9, a support spring 10, a gear shaft 11, a gear gasket 12 and a blade hood 13.

[0040] The bottom of the impeller 1 is provided with a T-shaped slot 102 for driving the slider 3 to move, an impeller bottom cavity 103 for accommodating the movement of the driving slider connecting rod 4 and the double-headed crank 5, and an impeller bottom boss 106. An impeller top shaft hole 105 is provided at the top of the impeller 1. A plurality of middle square grooves 104 corresponding to the blade hoods are evenly distributed on the hole wall of the impeller top shaft hole 105. The bottom of the middle square groove 104 is provided with an shaft hole 107 for passing the gear shaft end 1102. The gear end 1101 of the gear shaft passes through the shaft hole 107 and extends into the middle square groove 104 to engage with the rack 94 located in the middle square groove 104 for transmission.

[0041] One end of the return spring 2 is fixed to the end 101 of the T-slot at the bottom of the impeller, and one end of the return spring 2 is connected to the driving slider 3; the other end 32 of the driving slider 3 is connected to one end of the driving slider connecting rod 4, and the other end of the driving slider connecting rod 4 is connected to the double-headed crank 5, which is fixed by a double-headed crank hinge support 6, and the double-headed crank hinge support 6 is fixed to the impeller 1 by four screws 7, and the other end of the double-headed crank 5 is connected to the slider rack integrated part connecting rod 8, and the other end of the slider rack integrated part connecting rod 8 is connected to the slider rack integrated part 9. The block rack integrated part 9 transmits power to the gear shaft 11 through the rack 94, and the blade hood 13 is fixed on the gear shaft 11 and fits tightly with the blade inlet end by its own elastic force; when the impeller speed increases, the driving slider 3 moves linearly toward a position away from the impeller axis and drives the driving slider connecting rod 4, the double-headed crank 5, the slider rack integrated part connecting rod 8 and the slider rack integrated part 9 to move, thereby causing the gear shaft 11 and the blade hood 13 to rotate, changing the impeller blade inlet installation angle, and achieving the purpose of reducing the angle of attack and improving the efficiency of the compressor.

[0042] Specifically, a T-shaped slot 102 for the movement of the driving slider 3 is provided at the bottom of the impeller 1, and its direction is consistent with the direction of the blade inlet tip pointing to the blade root; an impeller bottom cavity 103 is provided above the bottom of the impeller 1 to accommodate the movement of the driving slider connecting rod 4 and the double-headed crank 5, and a mounting hole 108 (a threaded hole) for installing the double-headed crank hinge support 6 is provided on the wall of the cavity. The double-headed crank hinge support 6 is locked and fixed to the mounting hole 108 by a number of screws 7.

[0043] The T-shaped slots 102 , the impeller bottom cavity 103 , the middle square slots 104 , the shaft holes 107 and the like of the impeller 1 are evenly arranged in several groups along the circumferential direction, and the number of the groups is the same as the number of the impeller blades.

[0044] The direction of the shaft hole 107 of the impeller 1 is consistent with the direction from the blade inlet tip to the blade root.

[0045] The impeller bottom boss 106 is in contact with the impeller 1 and other parts of the compressor. The impeller bottom boss 106 is integrated with the impeller by welding or integral processing.

[0046] One end of the return spring 2 is fixed to the end 101 of the T-slot at the bottom of the impeller by welding, and the other end is connected to the ring 31 of the driving slider 3 (it can be a fixed connection or a hook connection to ensure that the two are not separated).

[0047] The other end of the driving slider 3 is provided with a driving slider hinge support 32 which is hinged to the driving slider connecting rod 4; the driving slider 3 is provided with a rail holding boss 33 extending toward both ends of the bottom of the T-slot 102. The cooperation between the rail holding boss 33 and the T-slot 102 ensures that the driving slider 3 has the freedom to move only in the horizontal direction along the T-slot 102.

[0048] When the driving slider 3 is running under the working condition that the impeller 1 is higher than the design speed, the centrifugal force it generates is greater than the elastic force of the return spring 2, and the driving slider 3 moves in the direction away from the axis of the impeller 1 and compresses the return spring 2; when the impeller 1 is reduced to the working condition of the design speed or below, the driving slider 3 moves in the direction close to the axis of the impeller 1, the return spring 2 is reset, and the driving slider 3 returns to its initial state position.

[0049] One end of the driving slider connecting rod 4 is hinged to the driving slider 3, and the other end is hinged to the long end 51 of the double-headed crank 5; the double-headed crank 5 is hinged to the double-headed crank hinge support 6 at the double-headed crank rotation center 52. When the impeller 1 runs at a speed higher than the design speed, the double-headed crank can rotate around the double-headed crank hinge support 6 by a certain angle to transfer kinetic energy; the other end of the double-headed crank 5, the short end 53 of the double-headed crank 5, is hinged to one end of the slider-rack integrated part connecting rod 8; the other end of the slider-rack integrated part connecting rod 8 is hinged to the slider-rack integrated part 9; when the impeller runs at a speed higher than the design speed, the slider-rack integrated part connecting rod 8 moves with the double-headed crank 5 to transfer kinetic energy.

[0050] The slider rack integral part 9 has a hinge support 91 at the lower end thereof and is hinged to the upper end of the slider rack integral part connecting rod 8; when the impeller 1 is running at a speed higher than the design speed, it moves along with the slider rack integral part connecting rod 8 to transfer kinetic energy; the other end of the slider rack integral part 9 is a vertical square rod 92 which is vertically upward as a whole, and a horizontal rod 93 which is perpendicular to the vertical square rod is connected to the top of the vertical square rod 92, and a rack 94 which is perpendicular to the horizontal rod is provided at the end of the horizontal rod 93, and the back of the rack 94 of the sliding rack integral part 9 is affixed to the vertical wall of the middle square groove 104 to ensure the meshing of the rack and the gear end of the gear shaft.

[0051] One end of the support spring 10 is welded to the wall of the shaft hole 105 at the top of the impeller, and the other end of the support spring 10 contacts the bottom end of the horizontal rod 93 of the slider rack integral part 9, so that the rack, gear shaft and blade hood can be driven to return to their initial state when the driving slider and the driving slider connecting rod do not pull the slider rack integral part.

[0052] The support spring 10 is used to support the weight of the slider rack integrated part 9; when the impeller 1 rotates at a speed higher than the design speed, it moves along with the slider rack integrated part 9.

[0053] A gear washer 12 composed of two identical halves is provided on the shaft end of the gear shaft near the gear end (the gear washer 12 is in the shape of a sleeve as a whole, and is cut into two identical halves along the axis). The gear washer 12 is used to cushion the axial direction of the gear shaft to ensure the engagement of the gear end with the rack 94. The gear washer 12 is made of two halves to facilitate its installation near the gear end, and the two halves can be made of magnetic material to avoid falling off the gear shaft.

[0054] The gear end 1101 of the gear shaft 11 is engaged with the rack 94 of the slider rack integral part 9, and its shaft end 1102 extending from the inside of the impeller 1 is connected to the root 1301 of the blade hood (fixed by welding or pin-key insertion interference fit); when the impeller 1 runs at a speed higher than the design speed, the gear shaft 11 and the blade hood are driven by the rack of the slider rack integral part 9 to rotate a certain angle.

[0055] Specifically, the blade hood 13 is fixed to the shaft end 1102 of the gear shaft 11, and the blade hood 13 and the gear shaft 11 are interference fit (the shaft end 1102 may have a cam, and the hole of the blade hood 13 may have a keyway, and the cam and the keyway are interference fit); when the impeller 1 operates at a speed higher than the design speed, the blade hood 13 rotates a certain angle together with the gear shaft 11 to adjust the angle of the impeller 1 blade inlet installation angle, thereby reducing the angle of attack and reducing flow loss.

[0056] The blade hood 13 is provided with a first elastic clamping petal 1303 and a second elastic clamping petal 1304. The first elastic clamping petal 1303 and the second elastic clamping petal 1304 are arc-shaped pieces arranged opposite to each other and have an elastic clamping function.

[0057] The two pieces of the first elastic hoop petals 1303 and the second elastic hoop petals 1304 are retracted toward the geometric center line of the blade hood 13, and are close to the surface of the impeller 1 inlet blade through elastic force; when the impeller 1 is running at a speed higher than the design speed, the blade hood 13 rotates a certain angle along with the gear shaft, and the first elastic hoop petals 1303 and the second elastic hoop petals 1304 can still fit the wall of the impeller blade inlet.

[0058] The blade cap 13 has a certain torsion angle along the axial direction of the gear shaft 11, and its value is consistent with the angle change value from the blade inlet root to the blade tip, so that the blade cap fits the blade tightly.

[0059] The blade hood 13 has a hole at one end close to the gear shaft for accommodating the gear shaft end, and has no hole at the side away from the gear shaft end, that is, the blade hood 13 is a countersunk hole for inserting the gear shaft end.

[0060] The beneficial effects of the patent of the present invention are: fast adjustment speed and high reliability, and the impeller blade inlet installation angle can be automatically adjusted according to the rotational speed, so that when the compressor is operated under conditions deviating from the design operating conditions, the impeller angle of attack can still be maintained within a smaller range. It not only has the characteristics of fast adjustment speed and high reliability, but also can broaden the operating range of the compressor and improve the efficiency of the compressor; at the same time, different blade hood leading edge geometries can be tested by rapid replacement, thereby accelerating the research and development and design of new impeller blade leading edge geometries.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solutions of the present invention. They should all be included in the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor, characterized by: The invention comprises an impeller (1) and a blade hood (13) provided on the inlet end of multiple blades of the impeller (1) and capable of rotating to change the installation angle of the blade inlet; the blade hood (13) has a first elastic hoop petal (1303) and a second elastic hoop petal (1304) abutting against the surface of the blade inlet end of the impeller (1); the air inlet side of the blade hood (13) is in a pointed cone shape; the end of the blade hood (13) is connected to a gear shaft (11); the impeller (1) is provided with a driving mechanism for driving the gear shaft to rotate; the driving mechanism is a rack (94) driven by centrifugal force, the rack (94) is meshed with the gear end (1101) of the gear shaft (11) for transmission; the center of the impeller (1) is provided with an impeller top shaft hole (105), the impeller top shaft hole (106) is provided with a gear shaft (1107) and the gear shaft (11108) is provided with a gear shaft (1111) and a gear shaft (1111) is provided with a gear shaft (1112) and a gear shaft (1111) is provided with a gear shaft (1112) and a gear shaft (1111) is provided with a gear shaft (1111) and a gear shaft (1112) is provided with a gear shaft (1111) and a gear shaft (1111) is provided with a gear shaft ( ... 05) is evenly provided with a plurality of middle square grooves (104) corresponding to the blade hoods, and the bottom of the middle square groove (104) is provided with an axial hole (107) for penetrating the shaft end (1102) of the gear shaft, and the gear end (1101) of the gear shaft extends into the middle square groove (104) and engages with the rack (94) located in the middle square groove (104) for transmission; the bottom surface of the impeller (1) is evenly provided with a plurality of T-shaped grooves (102) and a driving slider (3) slidably connected in the T-shaped grooves, and the driving slider (3) drives the rack (94) to move through the intermediate connecting member, so that when the impeller runs at high speed, the centrifugal force drives the slider to move away from the center of the impeller, and the gear shaft and the blade hood are driven to rotate by the intermediate connecting member and the rack, thereby changing the blade inlet installation angle.

2. The three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor according to claim 1 is characterized in that: A return spring (2) is installed in the T-shaped groove, one end of the return spring (2) abuts against the end (101) of the T-shaped groove at the bottom of the impeller, the other end of the return spring (2) is connected to the lifting ring (31) on the driving slider (3), the driving slider hinge support (32) on the driving slider (3) is hinged to one end of the driving slider connecting rod (4), the other end of the driving slider connecting rod is hinged to the long end (51) of the double-headed crank (5), and the double-headed crank rotation center (52) of the double-headed crank is rotatably connected to the double-headed crank. The double-headed crank hinge support (6) is fixed on the impeller, the double-headed crank short end (53) of the double-headed crank is hinged to one end of the slider rack integral part connecting rod (8), the other end of the slider rack integral part connecting rod (8) is hinged to the lower end of the slider rack integral part (9), the upper part of the slider rack integral part (9) is provided with the rack (94), and the driving slider connecting rod (4), the double-headed crank (5), the slider rack integral part connecting rod (8) and the slider rack integral part (9) constitute an intermediate connecting part.

3. The three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor according to claim 2, characterized in that: The setting direction of the T-slot (102) is consistent with the direction in which the blade inlet tip points to the blade root. An impeller bottom cavity (103) is provided above the bottom of the impeller (1) to accommodate the movement of the driving slider connecting rod (4) and the double-headed crank (5). A mounting hole (108) for mounting the double-headed crank hinge support (6) is provided on the wall surface of the impeller bottom cavity (103). The screw (7) passes through the double-headed crank hinge support (6) and is threadedly connected to the mounting hole (108) for fixation. The T-slot (102), the impeller bottom cavity (103), the middle square groove (104) and the shaft hole (107) of the impeller (1) are evenly arranged in several groups along the circumferential direction.

4. The three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor according to claim 3 is characterized in that: The blade hood (13) has a torsion angle along the axial direction of the gear shaft (11), and the torsion angle value is consistent with the angle change value from the blade inlet root to the blade tip, so that the first elastic clamp petal (1303) and the second elastic clamp petal (1304) of the blade hood can fit tightly on the blade inlet end surface.

5. The three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor according to claim 4, characterized in that: The slider rack integrated part (9) comprises a slider rack integrated part hinge support (91), a vertical square rod (92), a horizontal rod (93) and a rack (94) connected in sequence, and a support spring (10) is provided between the bottom end of the horizontal rod (93) and the middle square groove (104).

6. The three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor according to claim 4, characterized in that: The double-ended crank (5) has two straight rod sections, which are bent relative to each other to form an obtuse angle, and the bending point is located at the rotation center (52) of the double-ended crank.

7. The three-dimensional impeller structure with adaptive variable attack angle for a centrifugal compressor according to claim 4, characterized in that: A gear washer (12) composed of two halves is provided on the shaft end of the gear shaft near the gear end, and the gear washer (12) is used to cushion the gear shaft to ensure meshing of the gear end with the rack (94).

8. A method for operating a three-dimensional impeller structure with an adaptive variable attack angle for a centrifugal compressor as claimed in any one of claims 2 to 7, wherein when the impeller speed increases, the driving slider (3) moves linearly in the T-slot (102) toward a position away from the impeller axis and drives the driving slider connecting rod (4), the double-headed crank (5), the slider rack integral part connecting rod (8) and the slider rack integral part (9) to move, thereby causing the rack (94) on the slider rack integral part (9) to drive the gear end (1101) of the gear shaft (11) and the blade hood (13) to rotate, thereby changing the impeller blade inlet installation angle, thereby achieving the purpose of reducing the attack angle and improving the efficiency of the compressor.

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