35results about How to "Increase stall margin" patented technology

A centrifugal compressor with an air-bleed and a jetting box construction belongs to the turbo-machine field. The invention is characterized in that the wall of the box of worm frame is arranged with at least three exhaust-injection guide channels uniformly arranged around the rotary axle of compressor, while it contains exhaust channels and injection channels. The opening of the exhaust channels is arranged at the wall at the inlet of the non-blade expander channel, and vertical to the wall of inlet box. The opening of the injection channel is at the most torsion of the channel formed by the worm frame and blade, while it is at same direction of main absolute speed of most torsion. The exhaust channel and the injection channel are connected via the guide channel. The inventive exhaust-injection guide channel can exhaust the adhere layer at the wall of expander, restrain the flow separation of expander, and fill high-energy injection into the channel of blade wheel, to restrain the flow separation of adsorption face and restrain the flow separation at small flux, to improve the speed-lost allowance and efficiency.

The invention relates to a two-dimensional blade profile optimization method for a compressor considering a low Reynolds number working performance; the optimization method is characterized by comprising the following steps of: step 1: analyzing the meridional flow performance of a prototype multistage axial flow compressor at different rotating speeds; step 2: determining a key two-dimensional blade profile section to be optimized; step 3: performing parametric fitting to the key two-dimensional blade profile in step 2; step 4: analyzing the aerodynamic performance of the two-dimensional blade profile, and analyzing the aerodynamic performance of the parameterized two-dimensional blade profile to obtain the variable attack angle performance of the blade profile under a low Reynolds numberworking condition and the variable attack angle performance under a high Reynolds number working condition; and step 5: optimizing the modeling parameters of the two-dimensional blade profile, adjusting the two-dimensional modeling parameters according to the variable attack angle performance parameters of the two-dimensional blade profile obtained in step 4 at different Reynolds numbers, using agenetic algorithm to circularly iterate steps 3 and 4 until a two-dimensional blade profile design reducing loss and increasing stall margin is obtained, and then obtaining a new two-dimensional blade profile. According to the invention, the performance optimization of the two-dimensional blade profile of the axial flow compressor at different Reynolds numbers and different attack angles is realized; the designed working performance of the compressor is improved while the aerodynamic performance of the compressor at the low rotation speed working condition is improved; and the flow efficiencyis improved while the normal starting and stable working of the compressor are ensured.

The invention relates to an ellipse/circular arc chute processing machine box applying to a rotor blade tip end region of an axial flow compressor. For the design of the ellipse or circular arc chute processing machine box, the greater flow loss of the processing chute caused by the rectangular and trapezoid design of the traditional processing machine box is taken into account. Through the reasonable design of a geometric construction type of the processing chute, namely the combination design that an ellipse shape is adopted at the R direction (radial) and a circular arc shape is adopted at the Z direction (axial), the greater low loss caused by the rectangular and trapezoid design is avoided, thus the efficiency is not reduced, meanwhile the stall margin of the compressor is improved greatly for the ellipse or circular arc chute processing machine box.

The invention relates to a multi-arc chute processing machine box applying to a rotor blade tip end region of an axial flow compressor. For the design of the multi-arc chute processing machine box, the greater flow loss of the processing chute caused by the rectangular and trapezoid design of the traditional processing machine box is taken into account. Through the reasonable design of a geometric construction type of the processing chute, namely the combination design that a double-arc shape is adopted at the direction of the R direction and a circular arc shape is adopted for theta (circumference), the greater low loss caused by the rectangular and trapezoid design is avoided, thus the peak value efficiency is improved slightly, meanwhile the stall margin of the compressor is improved greatly for the multi-arc chute processing machine box.

The invention relates to a treatment casing applied to an axial-flow air compressor in the field of impeller machinery, in particular to an unsteady standing vortex type treatment casing, which can be used for improving the stability margin of the axial-flow air compressor without reducing efficiency. The unsteady standing vortex type treatment casing comprises an air jet groove, a bridge-type air flow channel and an air suction groove, wherein the air jet groove is arranged at the position of a suction surface of a blade, and the air suction groove is arranged at the position of a pressure surface of the blade. The treatment casing is designed to suppress leakage flow generated on the suction surface of a front edge of the blade, the air suction groove is exactly close to the pressure surface in the rear middle of the blade when the blade sweeps over, and the air jet groove is close to the suction surface of the front edge of the blade. Therefore, differential pressure is formed between the air suction groove and the air jet groove to drive fluids to spray from the downstream of the blade to the upstream of the blade, and the air jet groove is positioned close to the suction surface of the front edge of the blade and exactly aligned to a leakage vortex generating area of the blade, so that leakage flow can be suppressed, and further the stall margin of the air compressor is increased. Moreover, as an air jet direction is consistent with a main flow direction, mixing loss of an air jet area and a main flow area is decreased, the momentum of a boundary layer of the wall surface of the casing is increased, and positive effects are achieved for the efficiency of the air compressor.

The invention provides a circumferential groove casing treatment method of a centrifugal compressor. The circumferential groove casing treatment method completely takes structure characteristics and internal flow situations of the centrifugal compressor into consideration. A groove is arranged in a position prone to speed reduction of a diffuser channel along the circumference of a wheel cap side so as to provide a backflow channel for low-speed fluid in a top area of the diffuser, and then lower-power fluid lump is pumped into a treatment groove and transported along the circumference direction and flow direction of the treatment groove. In the process, only part of the fluid refills into a main fluid, the area of lower-power fluid is reduced and flow speed is improved, flow situations of the top channel of the diffuser are improved, blocking of the top channel is weakened, steady operation range of the compressor is enlarged greatly, and meanwhile peak value efficiency and pressure ratios are improved.

The invention provides a very-high-pressure intercooling cycle turbofan engine. The engine comprises fans, a high-pressure air compressor, an intercooler, a very-high-pressure air compressor, a combustion chamber, a circular rotating fan transition section, a very-high-pressure turbine, a high-pressure turbine, a low-pressure turbine, a low-pressure shaft, a high-pressure shaft and a very-high-pressure shaft. The fans, the high-pressure air compressor, the intercooler, the very-high-pressure air compressor, the combustion chamber, the circular rotating fan transition section, the very-high-pressure turbine, the high-pressure turbine and the low-pressure turbine are connected in sequence. The very-high-pressure turbine drives the very-high-pressure air compressor to operate through the very-high-pressure shaft. The high-pressure turbine drives the high-pressure air compressor to operate through the high-pressure shaft. The low-pressure turbine drives the fans to operate through the low-pressure shaft. The rotation central axis of the very-high-pressure air compressor, and the axis of the combustion chamber are both parallel to the axis of the engine but not coincide with the axis ofthe engine. The high-pressure air compressor is composed of a multi-stage high-load axial flow air compressor and a single-stage high-through-flow centrifugal/oblique flow air compressor.

The invention discloses a fan and a microwave oven. The fan comprises a hub (22) and multiple blades (22) which are arranged at intervals in the circumferential direction of an outer ring (211) of thehub (21), the blade thickness of the blade-shaped cross section of the blades (22) is gradually reduced from leading edges (223) to tailing edges (224) of the blades, and the blade-shaped cross section is cut out from a radial concentric circle of the outer ring (211) of the hub (21). Therefore, the fan has large stall margin, even if the incoming flow of the inlet blast capacity is high incidence, the separation of boundary layers still cannot occur on the blades, thus generation of stall is avoided, and normal work can still be conducted. Meanwhile, the fan has higher adaptability to the inlet incoming flow, the aerodynamic performance of the fan is better, the blast capacity is larger, and the efficiency is higher. Besides, due to the design of sharp angles of trailing edges of the blades, the tails of the blades are a series of fragmentized small vortex structures, the generation of high broad-band noise is avoided, and thus a certain noise-reduction effect is achieved.

The invention discloses a low-noise and efficient cooling axial flow fan of a central air conditioner outdoor unit. The low-noise and efficient cooling axial flow fan comprises an air duct, a motor support, a motor, a hub a plurality of blades which are fixed on the hub, wherein the motor support is arranged above the air duct, the motor is arranged at the center of the motor support, and the hub is connected with a motor rotary shaft. The hub comprises a hub inner lining panel and a shaft sleeve which is connected to the center of the hub inner lining panel in a welded mode; the shaft sleeve is matched with the motor rotary shaft; the periphery of the hub inner lining panel extends to form a plurality of hub connection boards which are evenly distributed with the shaft sleeve as the center; each hub connection board is provided with a plurality of thread hole; each hub connection board is twisted in the reverse direction from the two side edges of the primary portion where the hub inner lining panel extends. The low-noise and efficient cooling axial flow fan of the central air conditioner outdoor unit lowers vortex loss of the wall surface by decreasing the hub ratio, and decreases flowing speed of air flow, thereby effectively lowering noises caused by the air flow.

The invention relates to a front edge design method of a transonic speed fan blade top primitive blade profile. The front edge design method comprises the steps that a reference point distant from anoriginal front edge by a certain length is obtained on a suction surface of a blade top original primitive blade profile; a linear section is made by passing the reference point, wherein a certain included angle is formed between the original suction surface and the linear section; and the linear section is connected with an original pressure surface by an arc section with a small radius, the other end of the linear section is in smooth transition with the original suction surface by a chamfer, and the axial positions of a new blade front edge and an old blade front edge are kept unchanged. Since the front edge of the blade top original primitive blade profile is subjected to sharpening treatment and the effective radius of the front edge is reduced, shock wave detachment may be delayed, and the surge-to-stall margin of a fan can be improved advantageously. In addition, with the introduction of a sharpening structure, an expansion wave at the blade front edge is split into two parts, wherein one part is an expansion wave triggered by the front edge radius and the other part is an expansion wave triggered by the transition part of the linear section and the suction surface, so thatthe mach number before a channel shock wave can be lowered advantageously, and the efficiency of the blade top original primitive blade profile is improved.

The invention relates to an asymmetric double-circular-arc chute processing casing, which is applied to a tip region of a rotor blade of an axial flow gas compressor. The design of the asymmetric double-circular-arc chute processing casing is as follows: firstly, a circular-arc chute processing casing is used as a base and a circular-arc groove bottom structure is additionally arranged, so that a radial direction and an axial direction of the processing casing are circular-arc structures; an asymmetric structure is adopted in a peripheral direction and the peripheral direction is divided into two processing regions and two non-processing regions in 360 degrees; and the two processing regions are 106 degrees and 74 degrees respectively and are divided by two 90-degree non-processing regions. Therefore, on one hand, a double-circular-arc structure is used for avoiding greater flowing loss caused by rectangular and trapezoid designs; and on the other hand, the asymmetric structure is used for simultaneously generating coupling stimulation effect on different vortexes, so that the margin of the gas compressor is greatly improved and the efficiency is not reduced.