WO2022105207A1

WO2022105207A1 - Closed impeller and compressor

Info

Publication number: WO2022105207A1
Application number: PCT/CN2021/099960
Authority: WO
Inventors: 靳普
Original assignee: 至玥腾风科技集团有限公司
Priority date: 2020-11-18
Filing date: 2021-06-15
Publication date: 2022-05-27
Also published as: CN112503022A

Abstract

A closed impeller and a compressor containing a closed impeller. The closed impeller comprises a rear cover (201), blades (202), a sleeve body (203) and a front cover (204), wherein the front cover (204) covers the blades (202), and the front cover (204) is in a circular truncated cone shape; an air inlet surface is a curved surface that smoothly transitions along the contour of the ridge line of the blades (202), a back air surface is provided with grooves that match the end parts of the blades (202), and the end parts of the blades (202) corresponding to each groove are embedded into the grooves for a tight fitting connection; a flow channel (205) is formed between the blades (202), the rear cover (201), and the front cover (204); the tail part of the front cover (204) and the rear cover (201) are separated from one another by the blades (202) into spaced air outlets (206), and gas passes through the flow channel (205) and flows out of the air outlets (206) by means of the front parts of the blades (202).

Description

A closed impeller and compressor

technical field

The invention relates to a closed impeller and a compressor, belonging to the technical field of compressors.

Background technique

Industrial gas turbines mainly include three components: compressor, combustion chamber and turbine. The compressor is a component that uses high-speed rotating blades to work on the gas (mostly air) to increase the gas pressure. It compresses the air into high-temperature and high-pressure air, and then supplies fuel to the combustion chamber for combustion, and the generated high-temperature and high-pressure gas expands in the turbine. acting. The impellers used in the compressor are divided into open type, semi-open type and closed type. The characteristics of the three types of impellers are as follows:

Open impeller: The friction loss and flow resistance are large, the impeller efficiency is the lowest, and it is easy to generate vibration, so it is not suitable to work at high speed.

Semi-open impeller: The friction loss and flow resistance are smaller than that of the open impeller, the efficiency is higher, and it has a certain rigidity and strength, allowing it to work at a higher peripheral speed.

Closed impeller: The friction loss and flow resistance are the smallest, and the efficiency is the highest. However, due to the complex structure and heavy weight, and the wheel cover will generate huge stress on the blades when rotating, its strength is poor, and it is not suitable for high-speed conditions.

Most of the impellers used in current compressors are semi-open impellers. The challenge that needs to be overcome in the development of a compressor is how to obtain low friction loss and flow resistance, high efficiency, light weight and high strength.

In addition, the current compressor generally uses a bearing set composed of multiple radial bearings and thrust bearings, which often requires a long enough shaft for installation, which brings the problem that the axial dimension of the compressor increases. Used in micro gas turbine generator sets and other equipment, it will increase the space occupied by the equipment and increase the overall weight, which is not conducive to integrated design; and the processing and assembly errors caused by the arrangement of multiple bearings will increase, processing and assembly. Difficulty is high.

SUMMARY OF THE INVENTION

In view of the above prior art, the present invention provides a closed impeller with small friction loss, small flow resistance, high efficiency, light weight and high strength. The invention also provides a compressor with the closed impeller structure.

The present invention is achieved through the following technical solutions:

A closed impeller includes a rear cover, blades, a sleeve body and a front cover, wherein the rear cover is arranged at the tail end of the sleeve body, and the rear cover and the center of the sleeve body are provided with an integral through hole for sleeved and fixed on the rotating shaft ; The blades are arranged around the sleeve body and rotate in the same direction, one end of the blade is connected with the outer wall of the sleeve, and the other end is connected with the end face of the rear cover; the front cover is set on the blade, and the front cover is in the shape of a truncated cone; the air inlet surface of the front cover It is a curved surface with a smooth transition along the contour of the ridge line of the blade. The back air surface is provided with grooves that match the ends of the blades, and the ends of the blades corresponding to the grooves are embedded in the grooves for tight connection; the blades, the rear cover and the front cover are connected. A flow channel is formed between the front cover and the rear cover, and the air outlet is separated by the blades, and the gas flows out from the air outlet through the flow channel from the front of the blade.

Further, the rear cover, the blade and the sleeve body are integrally formed.

Further, the outer edge of the blade protrudes from the end face of the rear cover in the axial direction.

Further, the blade includes a longer main blade and a shorter splitter blade, and the main blade and the splitter blade are arranged at intervals in sequence. The front cover grooves are divided into main blade grooves and splitter blade grooves, which are respectively set at the ends of the main blades and the splitter blades.

Further, the leading edge of the front cover protrudes from the leading edge of the blade, or is flatter than the leading edge of the blade, or is shorter than the leading edge of the blade.

Further, the front cover is made of carbon fiber composite material. The specific preparation method is:

Step A, the carbon fiber of the set volume is put into the oil bed, and the carbon fiber is infiltrated with the liquid binder in the oil bed;

Step B, extracting the fully infiltrated carbon fiber, and extruding it to remove excess glue;

Step C, winding the carbon fiber after extruding the excess glue to form a sponge-like carbon fiber covered with the glue and having a three-dimensional structure;

Step D, vacuumizing the sponge-like carbon fiber covered with adhesive and having a three-dimensional structure, so that the gas in the three-dimensional structure of the carbon fiber is extracted;

Step E, injecting the liquid steel base material into the carbon fiber three-dimensional structure through a micro-syringe, and performing micro-vibration on the carbon fiber three-dimensional structure during the injection process, to obtain a composite material of the steel base material and the carbon fiber covered with adhesive;

In step F, the steel-based material and the composite material covered with the adhesive carbon fiber are put into a mold for pressure cooling and molding to obtain a formed steel-based carbon fiber composite front cover connected by chemical bonds.

A compressor includes a rotating shaft, an impeller and a motor are sleeved on the rotating shaft, and the structure of the impeller is as described above.

Further, the closed impeller cover is provided with a stator, and the part of the stator facing the front cover is evenly opened with one or more circles of air holes, which can be decomposed into axial and radial airflow after air intake. The impeller is suspended in the stator and rotates stably, the axial airflow pushes the impeller backward, and the stator is used as an air bearing and also plays the role of a radial bearing and a thrust bearing.

Further, one side or/and both sides of the motor is provided with a radial bearing sleeved on the rotating shaft, or no radial bearing is provided. When there are two radial bearings, it is equivalent to a total of three radial bearing supports, the overall vibration is small, and the operation is stable. When there is no radial bearing or only one of them is included, the length of the rotating shaft is shortened, it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the reliability of the whole machine is high.

Further, the radial bearing is an air bearing.

Further, a thrust bearing may or may not be provided on the rotating shaft, which is determined according to the calculation result of the axial force. If the axial force is too large and difficult to offset, a thrust bearing needs to be provided.

The closed impeller and compressor of the present invention are provided with a detachable front cover, the front cover is in the shape of a truncated cone, the air inlet surface is a curved surface with a smooth transition along the contour of the ridge line of the blade, and the back air surface is provided with a surface that matches the end of the blade. Groove, small friction loss, small flow resistance and high efficiency during operation; close engagement between the front cover and the blade during operation, the gas flows out from the air outlet from the front of the blade through the flow channel, and there is very little gas leakage. The front cover is made of carbon fiber composite material. The impeller is light in overall weight and has high strength. The blade (metal material) will expand when rotating, while the front cover does not expand. Therefore, with the increase of rotation speed and time, the blade and the front cover will not expand. The occlusion between the grooves of the blades will become tighter and tighter (when the stator is provided as an air bearing, its intake air will also be applied to the front cover to further prevent the separation of the blades and the grooves of the front cover), which is suitable for high-speed rotation conditions. The provision of splitter vanes can not only reduce the blockage of the inlet air flow, but also improve the slip coefficient of the impeller outlet, which not only improves the efficiency of the impeller, but also improves the overall efficiency of the compressor due to the improved flow field at the impeller outlet.

The front cover of the present invention is made of carbon fiber composite material. By adding steel matrix, carbon fiber and adhesive, the formed composite material far exceeds the upper limit of the modulus of conventional various steel matrix materials, and the rigidity is greatly increased. The tensile strength and fracture force of steel have been greatly improved, and the shear strength has also been greatly improved, and its performance is much higher than that of ordinary steel; at the same time, production costs, process thresholds, batch processes, and versatility are all controlled in metal materials. Within the system, industries that need high-performance materials generally benefit.

The compressor of the present invention is provided with an oblique thrust structure, and the stator is used as an air bearing and plays the role of a radial bearing and a thrust bearing at the same time (gas is introduced into the gap between the stator and the impeller from the air hole, so that the gap is evenly formed. The stable air film makes the impeller rotate stably in the stator, thus playing the role of air bearing), which can reduce or even replace the original radial bearing and thrust bearing. When the stator is also used as a thrust bearing, if other radial bearings are installed on the rotating shaft, it is equivalent to having multiple radial bearings for support, the overall vibration is small, and the operation is stable. If there are no other radial bearings or only a small amount of radial bearings on the rotating shaft, the length of the rotating shaft can be shortened, it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the reliability of the whole machine is high.

Various terms and phrases used herein have their ordinary meanings as known to those skilled in the art. If the terms and phrases mentioned are inconsistent with the known meanings, the meanings expressed in the present invention shall prevail.

Description of drawings

Figure 1: Schematic diagram of the closed impeller of the present invention.

Figure 2: Schematic diagram of the structure of the back cover, the blade and the sleeve body.

Figure 3: Front view of Figure 2.

Figure 4: Side view of Figure 2.

Figure 5: Sectional view at position A-A in Figure 4.

Figure 6: Schematic diagram of the assembly relationship between the closed impeller and the stator of the present invention.

Figure 7: The fabrication flow chart of the front cover.

Figure 8: Schematic diagram of the oblique thrust structure with the stator also serving as an air bearing.

Figure 9: Schematic diagram of the structure of radial bearings sleeved on the rotating shaft on both sides of the motor.

Figure 10: A schematic diagram of the structure of a radial bearing sleeved on the rotating shaft on one side of the motor.

Figure 11: Schematic diagram of the structure without radial bearings on both sides of the motor.

Among them, 1-shaft, 2-impeller, 201-back cover, 202-blades, 203-body, 204-front cover, 205-runner, 206-air outlet, 3-static, 301-air hole, 4-motor .

Detailed ways

The present invention will be further described below in conjunction with the examples. However, the scope of the present invention is not limited to the following examples. It will be understood by those skilled in the art that various changes and modifications can be made in the present invention without departing from the spirit and scope of the inventions.

Example 1

A closed impeller includes a rear cover 201, blades 202, a sleeve body 203 and a front cover 204, as shown in Figures 1 to 5, wherein the rear cover 201 is arranged at the rear end of the sleeve body 203, and the rear cover 201 and the sleeve body An integrated through hole is set in the center of 203 for sleeve and fixed on the rotating shaft 1; the blade 202 is arranged around the sleeve body 203 and rotates in the same direction, one end of the blade 202 is connected with the outer wall of the sleeve body 203, and the other end is connected with the end face of the rear cover 201 The front cover 204 is covered on the blade 202, and the front cover 204 is in the shape of a truncated truncated ring; the air inlet surface of the front cover 204 is a curved surface that smoothly transitions along the contour of the ridge line of the blade 202, and the back air surface is provided with the end of the blade 202. The end of the blade 202 corresponding to each groove is embedded in the groove and tightly connected; a flow channel 205 is formed between the blade 202, the rear cover 201 and the front cover 204; the tail of the front cover 204 and the rear cover 201 The air outlet 206 is spaced apart by the 202, and the gas flows out from the air outlet 206 from the front part of the blade 202 through the flow channel 205.

The rear cover 201 , the blades 202 and the sleeve body 203 are integrally formed, as shown in FIGS. 2 to 5 .

The outer edge of the blade 202 protrudes from the end surface of the rear cover 201 in the axial direction.

The blade 202 includes a longer main blade and a shorter splitter blade, and the main blade and the splitter blade are arranged in sequence at intervals. The grooves of the front cover 204 are divided into main blade grooves and splitter blade grooves, which are respectively provided at the ends of the main blade and the splitter blade.

The leading edge of the front cover 204 protrudes from the leading edge of the blade 202 , or is flatter than the leading edge of the blade 202 , or shorter than the leading edge of the blade 202 .

The front cover 204 is made of carbon fiber composite material, and the specific preparation method is (the flowchart is shown in FIG. 7 ):

Step D, the spongy carbon fiber that is covered with adhesive and has three-dimensional structure is vacuumed, so that the gas in the three-dimensional structure of carbon fiber is drawn out;

A compressor includes a rotating shaft 1, as shown in FIG. 6, an impeller 2 and a motor 4 are sleeved on the rotating shaft 1, a stator 3 is set on the outer cover of the impeller 2, and the structure of the impeller is as described above.

A gas turbine adopts the above-mentioned compressor.

The above-mentioned closed impeller and compressor are provided with a detachable front cover, the front cover is in the shape of a truncated cone, the air inlet surface is a curved surface with a smooth transition along the contour of the ridge line of the blade, and the back air surface is provided with a groove that matches the end of the blade. , When working, the friction loss is small, the flow resistance is small, and the efficiency is high; when working, the front cover and the blade are tightly engaged, and the gas flows out from the air outlet from the front of the blade through the flow channel, and the gas leakage is very small. The front cover is made of carbon fiber composite material. The impeller is light in overall weight and has high strength. The blade (metal material) will expand when rotating, while the front cover does not expand. Therefore, with the increase of rotation speed and time, the blade and the front cover will not expand. The occlusion between the grooves will become tighter and tighter, which is suitable for high-speed rotation conditions. The provision of splitter vanes can not only reduce the blockage of the inlet air flow, but also improve the slip coefficient of the impeller outlet, which not only improves the efficiency of the impeller, but also improves the overall efficiency of the compressor due to the improved flow field at the impeller outlet.

The front cover is made of carbon fiber composite material. Through the addition of steel matrix, carbon fiber and adhesive, the formed composite material far exceeds the upper limit of the modulus of conventional steel matrix materials, and the stiffness is greatly increased. The tensile strength, breaking force, and shear strength have also been greatly improved, and their properties are much higher than those of ordinary steel; at the same time, production costs, process thresholds, batch processes and versatility are all controlled within the metal material system. It has generally benefited industries that require high-performance materials.

Example 2

A compressor, comprising a rotating shaft 1, an impeller 2 and a motor 4 are sleeved on the rotating shaft 1; wherein, the structure of the impeller is: including a rear cover 201, blades 202, a casing 203 and a front cover 204, as shown in Figures 1-5 , wherein the rear cover 201 is arranged at the rear end of the sleeve body 203, and an integral through hole is set in the center of the rear cover 201 and the sleeve body 203 for sleeved and fixed on the rotating shaft 1; the blades 202 are arranged around the sleeve body 203 and face the same direction Rotating, one end of the blade 202 is connected with the outer wall of the sleeve body 203, and the other end is connected with the end face of the rear cover 201; the front cover 204 is covered on the blade 202, and the front cover 204 is in the shape of a circular truncated ring; the air inlet surface of the front cover 204 is along the blade 202 The curved surface of the ridge line is smooth and transitional, the back air surface is provided with grooves that match the ends of the blades 202, and the ends of the blades 202 corresponding to the grooves are embedded in the grooves for tight fitting connection; the blades 202, the rear cover 201 and the front A flow channel 205 is formed between the covers 204; the outer edge of the blade 202 protrudes from the end face of the rear cover 201 in the axial direction; the tail of the front cover 204 and the rear cover 201 are separated by the blades 202 into an air outlet 206, and the gas is separated by the blades 202. The front part flows out from the air outlet 206 through the flow channel 205 .

The front cover 204 is made of carbon fiber composite material.

The closed impeller cover is provided with a stator 3. As shown in FIG. 8, the part of the stator 3 facing the front cover 204 is evenly opened with one or more circles of air holes 301, which can be decomposed into axial and radial after air intake. Air flow, radial air flow will make the impeller suspended in the stator 3 to rotate stably, the axial air flow will push the impeller backward, the stator 3 is used as an air bearing and plays the role of a radial bearing and a thrust bearing at the same time.

Both sides of the motor are provided with radial bearings sleeved on the rotating shaft (FIG. 9), or one side is equipped with radial bearings sleeved on the rotating shaft (FIG. 10), or no radial bearings are provided (FIG. 11). When there are two radial bearings, it is equivalent to a total of three radial bearing supports, the overall vibration is small, and the operation is stable. When there is no radial bearing or only one of them is included, the length of the rotating shaft is shortened (in Figures 9 to 11, the shaft length is shortened in turn), it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the whole machine is reliable. Sex is high.

The radial bearing is an air bearing.

The rotating shaft may or may not be provided with a thrust bearing, which is determined according to the calculation result of the axial force. If the axial force is too large and difficult to offset, a thrust bearing needs to be provided.

The above-mentioned compressor is equipped with an oblique thrust structure, and the stator is used as an air bearing and plays the role of a radial bearing and a thrust bearing at the same time (gas is introduced into the gap between the stator and the impeller from the air hole, so that a uniform and stable air is formed in the gap. air film, so that the impeller rotates stably in the stator, so as to play the role of air bearing), which can reduce or even replace the original radial bearing and thrust bearing. When the stator is also used as a thrust bearing, if other radial bearings are installed on the rotating shaft, it is equivalent to having multiple radial bearings for support, the overall vibration is small, and the operation is stable. If there are no other radial bearings or only a small amount of radial bearings on the rotating shaft, the length of the rotating shaft can be shortened, it is easy to ensure the coaxiality of the parts on the shaft, the processing is easier, the integration is high, and the reliability of the whole machine is high. In addition, the air intake of the air hole will be applied to the front cover, which can better prevent the separation of the blade and the groove of the front cover, and is more suitable for high-speed rotation conditions.

The foregoing examples are provided to those skilled in the art to fully disclose and describe how to make and use the claimed embodiments, and are not intended to limit the scope of the disclosure herein. Modifications obvious to those skilled in the art are intended to be within the scope of the appended claims.

Claims

A closed impeller is characterized in that it includes a rear cover, blades, a sleeve body and a front cover, wherein the rear cover is arranged at the rear end of the sleeve body, and an integral through hole is arranged in the center of the rear cover and the sleeve body for sleeve and It is fixed on the rotating shaft; the blades are arranged around the sleeve body and rotate in the same direction, one end of the blade is connected with the outer wall of the sleeve, and the other end is connected with the end face of the rear cover; the front cover is set on the blade, and the front cover is in the shape of a circular cone; The air inlet surface is a curved surface with a smooth transition along the contour of the ridge line of the blade, and the back air surface is provided with a groove that matches the end of the blade, and the end of the blade corresponding to each groove is embedded in the groove for a tight fit connection; the blade, the rear cover A flow channel is formed between the front cover and the front cover; the air outlet is spaced by the blades between the tail of the front cover and the rear cover, and the gas flows out from the air outlet through the flow channel from the front of the blade.
The closed impeller according to claim 1, characterized in that: the back cover, the vanes and the sleeve body are integrally formed; or/and: the outer edge of the vanes protrudes from the end face of the back cover in the axial direction.
The closed impeller according to claim 1, characterized in that: the blades comprise longer main blades and shorter splitter blades, the main blades and the splitter blades are arranged at intervals in sequence; the front cover groove is divided into main blades The grooves and the splitter vane grooves are respectively arranged corresponding to the ends of the main vanes and the splitter vanes.
The closed impeller according to claim 1, characterized in that: the leading edge of the front cover protrudes from the leading edge of the blade, or is parallel to the leading edge of the blade, or is shorter than the leading edge of the blade.
The closed impeller according to claim 1, wherein the front cover is made of carbon fiber composite material.
The closed impeller according to claim 5, wherein the front cover is prepared by the following method:

Step A, the carbon fiber of the set volume is put into the oil bed, and the carbon fiber is infiltrated with the liquid binder in the oil bed;

Step B, extracting the fully infiltrated carbon fiber, and extruding it to remove excess glue;

Step C, winding the carbon fiber after extruding the excess glue to form a sponge-like carbon fiber covered with the glue and having a three-dimensional structure;

Step D, vacuumizing the sponge-like carbon fiber covered with adhesive and having a three-dimensional structure, so that the gas in the three-dimensional structure of the carbon fiber is extracted;

Step E, injecting the liquid steel base material into the carbon fiber three-dimensional structure through a micro-syringe, and performing micro-vibration on the carbon fiber three-dimensional structure during the injection process, to obtain a composite material of the steel base material and the carbon fiber covered with adhesive;

In step F, the steel-based material and the composite material covered with the adhesive carbon fiber are put into a mold for pressure cooling and molding to obtain a formed steel-based carbon fiber composite front cover connected by chemical bonds.
A compressor, comprising a rotating shaft on which an impeller and a motor are sleeved, characterized in that the impeller is the closed impeller according to any one of claims 1 to 6.
The compressor according to claim 7, wherein the closed impeller cover is provided with a stator, and the portion of the stator facing the front cover is evenly provided with one or more circles of air holes.
The compressor according to claim 7 or 8, wherein a radial bearing sleeved on the rotating shaft is arranged on one side or/and both sides of the motor, or no radial bearing is arranged;

Or/and: a thrust bearing may or may not be provided on the rotating shaft.
A gas turbine using the compressor according to any one of claims 7 to 9.