CN109083849B

CN109083849B - Axial flow compressor

Info

Publication number: CN109083849B
Application number: CN201810922338.0A
Authority: CN
Inventors: 不公告发明人
Original assignee: Chengdu Hongsheng Technology Co ltd
Current assignee: Chengdu Hongsheng Technology Co ltd
Priority date: 2018-08-14
Filing date: 2018-08-14
Publication date: 2020-06-09
Anticipated expiration: 2038-08-14
Also published as: CN109083849A

Abstract

The invention discloses an axial-flow type air compressor, aiming at the problems that the single-stage pressurization ratio of the air compressor in the prior art is not high, the number of stages of the air compressor is large, the integral structure of the air compressor is large, and the last-stage blade of the air compressor is easy to damage.

Description

Axial flow compressor

Technical Field

The invention relates to a compressor, in particular to an axial flow compressor.

Background

The compressor is a device for gas pressurization, and the pressurization principle is that air is pressurized in a multi-stage manner through a plurality of compressor stages, but in the prior art, the single-stage pressurization ratio of the compressor is not high, the number of stages of the compressor is required under the condition of ensuring the total pressurization ratio, the overall structure of the compressor is large, and the final stage of the compressor is small in size along with the gas pressurization, and the small blades of the final stage are easy to damage.

Disclosure of Invention

Noun interpretation

Pushing by a shaftless pump: the shafting drive of the traditional propeller and the mechanical pump jet propeller is converted into the motor drive arranged on the outer revolution surface, so that the drive central shaft of the traditional power system is eliminated.

Blade cascade: the blade is cut off along the radial direction of the mounting shaft cylindrical surface of the blade, and then the section is expanded into a plane, so that the blade cascade is obtained.

A cascade flow channel: the gas flow path of two adjacent blades on a certain cascade plane.

Rotor blade: the blades are connected with a blade disc and synchronously rotate with a turbine shaft, and the mechanical energy can be converted into the kinetic energy and the pressure energy of air.

Stator blade: the blades fixed on the casing are stationary, and the blades behind the rotor blades can perform the functions of reducing the speed, increasing the pressure and rectifying the air flow at the outlet of the rotor blades.

Rectifying: and adjusting the direction of the airflow.

Compressor stage: the airflow enters from the rotor blade, flows out from the stator blade, and then flows into the next rotor blade, and the circulation is carried out. The rows of blades through which air flows in through the rotor blades and out through the stator blades during each cycle are referred to as a compressor stage.

Single-stage supercharging ratio: the degree of compression of the air in the compressor stage is a stage pressure ratio.

Total pressure ratio of the compressor: the degree of increase in the compressor of the air pressure entering the compressor. I.e. the ratio of the pressure of the last outlet flow of the compressor to the pressure of the initial inlet flow.

The invention aims to provide an axial flow compressor, and provides a solution to the problems that the single-stage supercharging ratio is not high, the number of stages of the compressor is large, the overall structure of the compressor is large, and the last-stage small blade of the compressor is easy to damage.

The invention is realized by the following technical scheme:

an axial flow compressor comprises a casing, a turbine shaft, rotor blades, stator blades and a blade disc; the blade disc is a connecting piece between the rotor blades and the turbine shaft and fixes the rotor blades and the turbine shaft into a whole and synchronously rotates, the rotor blades are uniformly distributed in an annular array in the radial direction of the blade disc and are distributed in a plurality of rows along the axial direction of the blade disc, the stator blades are fixed on the inner wall of the casing, a plurality of rows are uniformly distributed in an annular array in the radial direction of the casing and are distributed along the axial direction of the casing, the stator blades are staggered behind the rotor blades, the rotor blade and the stator blade also comprise a shaftless pump pushing mechanism and connecting screws, the shaftless pump pushing mechanism is positioned between a row of rotor blades and a row of stator blades and comprises a shell, a fixed bearing, a motor component and a shaftless blade component, the two side surfaces of the shell are in threaded connection with the side surfaces of the casing through connecting screws, an annular groove is formed in the inner wall of the shell, and a fixed bearing, a motor assembly and a fixed bearing are sequentially clamped in the annular groove of the inner wall to form an integrated whole; the motor assembly comprises a motor stator and a motor rotor, and the motor rotor is sleeved in the motor stator and can rotate freely; no shaft vane subassembly and motor element are inseparable and synchronous pivoted integrated structure, and no shaft vane subassembly is including rotatory ring, no shaft vane, and no shaft vane is located rotatory ring inboard, becomes an overall structure with rotatory ring, and rotatory ring cup joints in fixing bearing, confirms its axial position by fixing bearing, its characterized in that: the shaftless pump pushing mechanism is positioned between a row of rotor blades and a row of stator blades, two side surfaces of a shell of the shaftless pump pushing mechanism are in threaded connection with the side surface of a casing through connecting screws, the shaftless blades, the rotor blades and the stator blades jointly form a compressor stage, and the direction of airflow generated when the shaftless blades rotate in the same compressor stage is opposite to the direction of airflow generated by the rotor blades.

In the prior art, one compressor stage in the compressor consists of a row of rotor blades and a row of stator blades positioned behind the rotor blades, when the rotor blades rotate synchronously along with a turbine shaft, the rotor blades suck external air into a cascade runner of the rotor blades, and then the external air flows out of the cascade runner of the stator blades, and speed reduction and pressurization are realized in the process. The core idea of the present application is to utilize bernoulli's principle, which specifies that the faster the fluid flow speed, the lower the pressure, and vice versa, the greater the pressure, since the mechanical energy of the rotor blade will be converted into the initial kinetic energy and pressure energy of the air after the external air is sucked in and flows out through the cascade channel, i.e. the air will have an initial speed V1 and pressure P1, the forward speed is directed towards the stator blade, if a rotating device with blades can be provided, which is erected between the rotor blade and the stator blade, and the rotating energy thereof gives a reaction force to the outlet airflow of the rotor blade, the speed thereof can be reduced without fail, while the speed is reduced while the pressure is increased without fail, i.e. the pressurization of the air is achieved according to bernoulli's principle. According to the principle, the shaftless pump pushing mechanism is adopted, the shaftless blade is arranged on the shaftless pump pushing mechanism and is positioned between the rotor blade and the stator blade, and a motor set in the shaftless pump pushing mechanism is electrified to drive the motor rotor to rotate so as to drive the rotating ring and the shaftless blade on the motor rotor to rotateRotating, the shaftless blade rotation will generate a reaction force on the rotor blade outlet air flow, causing its speed to decrease and thus the pressure to increase. Therefore, under the condition that the original compressor stage only comprises a rotor blade disc and stator blades, the supercharging effect of the shaftless blades on the airflow is increased, the single-stage supercharging ratio is improved, and the total supercharging ratio P0 is 1.4 on the assumption that the single-stage average supercharging ratio in the prior art is 1.4 and the compressor stage number is 10¹⁰28.93, in the application, the front four-stage loading shaftless pumping mechanism is assumed to increase the average pressure ratio to 1.65, then the average pressure ratio is not changed to 1.4, and under the condition that the total pressure ratio is not changed, the compressor stage can be satisfied by only 8 stages, namely P1 is 1.65⁴×1.4⁴Approximately equal to 32.08 and greater than the original pressure increase ratio, P1>P0, the last 2 compressor stages are omitted compared to the original structure. Therefore, the volume of the compressor can be reduced, and along with the compression of the airflow, the cavity for containing the air of the compressor is smaller and smaller, the compressor stage with the minimum last two stages is omitted, the blades with the minimum last two stages are omitted, the blades are smaller and have lower strength and are more easily damaged, and the damage of the small blades is avoided.

Further, the mechanical energy generated by the shaftless pumping mechanism when rotating should be less than the mechanical energy generated by the rotor blades when rotating. If the mechanical energy generated by the shaftless pump pushing mechanism is larger than the rotor blade, the acting force of the shaftless blade on the rotor blade outlet airflow is larger than the acting force of the rotor blade on the outlet airflow, so that the outlet airflow generally has the tendency of flowing back towards the direction of the rotor blade, the airflow cannot flow into the next compressor stage, and the purpose of gas compression cannot be achieved.

Furthermore, the blade profile of the compressor stage shaftless blade is bent towards the axis, so that a cascade flow channel of the compressor stage shaftless blade forms a diffusion channel. The outlet airflow channel is larger than the inlet airflow channel, so that the cross-sectional area of the outlet airflow is larger than that of the inlet airflow, the cross-sectional area is increased under the condition of constant flow, the speed is reduced, and the pressure is increased according to the Bernoulli's law. The rotor blade and the stator blade also have the characteristics, the comprehensive consideration is that the initial speed V0 and the initial pressure P0 of the inlet airflow of the rotor blade are set, the rotor blade rotates to suck the airflow, the rotor blade does work on the airflow in the process to obtain the outlet airflow speed V1 and the pressure P1 of the rotor blade, and because the mechanical energy of the rotor blade is converted into the kinetic energy of the outlet airflow in the process, the outlet airflow V1 of the rotor blade is more than V0, and the pressure P1 is more than P0, the acceleration and the pressurization of the airflow on the rotor blade are realized; then, the air flow enters a shaftless blade, and the shaftless blade performs speed reduction and pressurization on the air flow in two steps: step 1, the rotation of the shaftless blade exerts a reaction force on airflow at an outlet of the rotor blade, the airflow is decelerated under the action of force, and in the deceleration process, as the rotation of the shaftless blade does work on the airflow, mechanical energy of the rotation of the blade is converted into pressure energy of the airflow, and the pressure intensity of the airflow is increased; step 2, airflow passes through a cascade flow channel diffused by a shaftless blade, the airflow speed is reduced when the airflow cross section is increased and the flow is not changed, and the airflow pressure is increased certainly when the speed is reduced according to Bernoulli's law, so that the airflow is decelerated and pressurized, the outlet airflow V2 and the pressure P2 of the shaftless blade are obtained through two steps, and V2< V1, P2> P1 can be obtained; and finally, the airflow enters the stator blade, and is subjected to speed reduction and pressurization in a cascade flow channel diffused by the stator blade to obtain stator blade outlet airflow V3 and pressure P3, and V3< V2, P3> P2 can be obtained. In conclusion, the airflow is accelerated and pressurized in the rotor blades, the shaftless blades are divided into two times of deceleration and pressurization, and the stator blades are decelerated and pressurized.

Further, the shaftless pumping mechanism is present in the first 4 stages of the compressor stages, i.e. at most 4 are allowed. The cavity between the casing and the blisk of the compressor can contain gas, the corresponding cavity volume is smaller and smaller along with the compression of the gas, the cavity volume after 4 stages is difficult to contain the shaftless pumping mechanism, and the shaftless pumping mechanism is arranged at the front 4 stages of the compressor stage.

Furthermore, the casing is connected with the shell, threaded through holes are formed in the casing connecting surface, threaded holes are formed in the shell connecting surface, the holes correspond to the holes one by one, the holes are uniformly distributed in an annular array along the center of a revolving body formed by the casing and the shell, and the number of the holes is different from 50 to 150 according to the diameter of the casing. The outer diameter of the compressor is large, the size is about 1500mm, the circular ring step surfaces of the connecting parts for machining threaded holes and accommodating connecting screws are small, the connecting parts are usually connected through screws of M5-M6, in order to guarantee the stability of connection, a circle of screws are usually arranged on the circular ring step surfaces as many as possible in an annular array mode to connect the circular ring step surfaces, the size is 1500mm, and when the connecting screws are M6, the experience number is 90-100.

Furthermore, the connecting screw is an outer hexagonal connecting screw provided with a safety hole, and the safety hole is positioned on the hexagonal side face. In order to connect and dismantle the convenience, choose outer hexagonal connecting screw for use, for preventing the not hard up of connecting screw in the use, go up the safety hole in six aspects, establish ties connecting screw through the safety hole with the fuse in proper order, play locking purpose each other.

Further, the material of the motor rotor is a Co50Fe-W composite material. Along with the pressurization of gas, the volume is smaller and smaller, the temperature is higher and higher, so that the conductor material in the motor can normally work at high temperature, and the rotor material of the motor is a Co50Fe-W composite material, so that the motor has the excellent characteristic of working at high temperature.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the invention aims to provide a gas compressor, which adopts a mode of additionally arranging a shaftless pumping mechanism to enable a shaftless blade, an original rotor blade and an original stator blade to form a new gas compressor stage, increases the supercharging effect of the shaftless blade on gas under the condition that the original gas compressor stage only has the rotor blade and the stator blade to supercharge the gas, increases the single-stage supercharging ratio, reduces the stage number of the gas compressor, reduces the integral structure of the gas compressor, saves the small blade required by the last stage gas compressor stage and avoids the damage of the blade.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 is a schematic view of the internal structure of the compressor of the present invention.

Fig. 2 is a schematic diagram of the structure of a single-stage compressor stage of the compressor of the present invention.

Fig. 3 is a schematic structural view of the shaftless pumping mechanism of the present invention.

FIG. 4 is a schematic view of the flow of the gas stream through the cascade channels of the present invention.

Fig. 5 is a schematic flow path of the gas flow of the present invention in a single stage compressor stage.

Reference numbers and corresponding part names in the drawings:

1-casing, 2-turbine shaft, 3-rotor blade, 4-shaftless pumping mechanism, 5-blade disc, 6-connecting screw, 7-stator blade, 41-shell, 42-fixed bearing, 43-motor component, 44-shaftless blade component, 431-motor stator, 432-motor rotor, 441-rotating ring, 442-shaftless blade

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1

Fig. 1, 2 and 3 are a preferred embodiment of the present invention:

fig. 1 is a schematic diagram of a composition structure of the compressor of the present application, which is composed of a plurality of compressor stages, the gas-containing cavities of the compressor stages decrease with the backward gas compression, so in order to ensure that the shaftless pumping mechanism 4 can be smoothly contained, the shaftless pumping mechanism 4 exists only in the first 4 stages, and the later compressor stages are composed of rotor blades 2 and stator blades 7 only.

Fig. 2 shows a compressor stage unit in a compressor, a blisk 5 fixedly connects rotor blades 2 and a turbine shaft 1 into an integrated whole body capable of rotating synchronously, stator blades 7 are fixed on a casing 1 and are stationary, a shaftless pumping mechanism 4 is arranged between the stator blades 7 and the rotor blades 2, and a connecting screw 6 connects the casing 1 and a housing 1 of the shaftless pumping mechanism 4.

Fig. 3 is a schematic structural diagram of the shaftless pumping mechanism 4, as shown in the figure:the shaftless pumping mechanism 4 comprises a housing 41, a fixed bearing 42, a motor assembly 43 and a shaftless blade assembly 44, wherein the motor assembly 43 comprises a motor stator 431 and a motor rotor 432, and the shaftless blade assembly 44 comprises a rotating ring 441 and a shaftless blade 442. The shell 1 is provided with an annular groove, the fixed bearings 42, the electronic component 43 and the fixed bearings 42 are sequentially clamped inside the annular groove, two side faces of a motor stator 431 of the electronic component 43 are connected with side faces of the two fixed bearings 42 in an interference fit mode, the electronic rotor 432 is sleeved with the motor stator 431 and can freely rotate, the rotating ring 441 and the shaftless blade 442 of the shaftless blade component 44 are of an integral structure, the rotating ring 441 is sleeved with the motor rotor 432 in an interference fit mode and is connected, and the shaftless blade 442 can synchronously rotate along with the electronic rotor 432. The shaftless blades 442, the rotor blades 3 and the stator blades 7 together form a compressor stage, and the direction of the airflow generated by the rotation of the shaftless blades 442 in the same compressor stage is opposite to the direction of the airflow generated by the rotor blades 3. The single-stage compressor stage of the compressor in the prior art only comprises rotor blades 3 and stator blades 7, the inlet airflow of one single-stage compressor stage flows out through cascade runners of the rotor blades 3 and the stator blades 7 to realize pressurization, and due to the fact that the structure is simple and the single-stage pressurization ratio is low, a shaftless pumping mechanism 4 is erected between the rotor blades 3 and the stator blades 7, the shaftless blades 442, the original rotor blades 3 and the original stator blades 7 form a new compressor stage, the shaftless blades 442 are powered by a motor assembly 43 and rotate under the driving of a motor rotor 432, when the shaftless blades 442 rotate, a reaction force is formed in the outlet airflow direction of the rotor blades 3, and according to Bernoulli's law, the outlet airflow flow velocity of the rotor blades 3 is reduced, the pressure is increased, and then the outlet airflow enters the stator blades 7. Because the gas is pressurized by the shaftless blade in the technical scheme, the single-stage pressurization ratio can be increased, if the total pressurization ratio is not changed, the increase of the single-stage pressurization ratio means that the stage number of the compressor can be reduced, and if the average pressurization ratio of the single stage in the prior art is 1.4 and the stage number of the compressor is 10, the total pressurization ratio P0 is 1.4¹⁰28.93, the average pressure ratio of the front four stages is increased to 1.65 and then does not become 1.4, and under the condition that the total pressure ratio is not changed, the compressor stageThe number is only 8 grades, i.e. P1-1.65⁴×1.4⁴Approximately equal to 32.08 and greater than the original pressure increase ratio, P1>P0, the last 2 compressor stages are omitted compared to the original structure. Therefore, the stage number of the compressor can be reduced by about 2 stages while the single-stage supercharging ratio is improved, and the integral structure of the compressor is reduced.

FIG. 4 is another embodiment of the present invention:

as shown in fig. 4: the blade profile of the shaftless blade 442 is bent toward the axis, so that in a cascade flow passage, the blade profile is bent to form a diffusion passage, the cross-sectional area of the outlet airflow is larger than that of the inlet airflow, when the airflow is flowing through the cascade flow passage, the flow rate is set as M, the cross-sectional area is set as S0 at the inlet, S1 at the outlet, the airflow speed at the inlet is V0, the airflow speed at the outlet is V1, when the flow rate is constant, M is S0 × V0 is S1 × V1, and because the cross-sectional area at the inlet is S0< S1, the airflow speed is V0> V1, the airflow speed at the outlet is reduced compared with that at the inlet, and the fluid speed is reduced and the pressure is increased according to Bernoulli' S law, and the airflow speed is reduced and pressurized after flowing through the cascade flow passage of the shaftless blade 442.

FIG. 5 is another embodiment of the present invention:

as shown in fig. 5, a compressor stage of the compressor includes a rotor blade 3, a shaftless blade 442 and a stator blade 7, all of which are blade-shaped and bent toward the axis, i.e., the cascade channel is a diffusion channel, so that when an airflow is sucked into the cascade channel by the rotor blade 3 at an initial speed, the mechanical energy generated by the rotation of the rotor blade 3 is converted into the kinetic energy of the air, and since the rotor blade 3 applies work to the airflow in this process, the airflow is accelerated and pressurized after passing through the rotor blade 3; then, the airflow flowing out of the rotor blade 3 is subjected to the reaction force of the rotation of the shaftless blade 442, the shaftless blade 442 applies work to the airflow, so that the airflow is decelerated and pressurized, the airflow continuously flows into the cascade flow channel of the shaftless blade 442, and the airflow is further decelerated and depressurized in the diffusive channel of the cascade flow channel of the shaftless blade 442; and finally, the gas flows into the stator blade 7, continues to reduce the speed and reduce the pressure in a cascade flow channel of the stator blade 7 and rectify the flow, and flows into the next compressor stage according to a certain flow direction. The air flow is accelerated and pressurized in the process of passing through the blade cascade flow channel of the rotor blade 3, then passes through the shaftless blade 442, the reaction force air flow formed by rotation is decelerated and pressurized between the rotor blade 3 and the blade cascade flow channel of the shaftless blade 442, then flows into the blade cascade flow channel of the shaftless blade 442 to continue decelerating and pressurizing, finally flows into the stator blade 7 to decelerate and pressurize, and flows into the next stage of compressor after being accelerated and pressurized for a plurality of times in the first stage of compressor.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. An axial flow compressor comprises a casing (1), a turbine shaft (2), rotor blades (3), a shaftless pump pushing mechanism (4), a blade disc (5), a connecting screw (6) and stator blades (7); the blade disc (5) is a connecting piece between the rotor blades (3) and the turbine shaft (2) and fixes the rotor blades (3) and the turbine shaft (2) into a whole to realize synchronous rotation, the rotor blades (3) are uniformly distributed in a radial annular array on the blade disc (5) and are distributed in a plurality of rows along the axial direction of the blade disc (5), the stator blades (7) are fixed on the inner wall of the casing (1), the stator blades (7) are uniformly distributed in a radial annular array on the casing (1) and are distributed in a plurality of rows along the axial direction of the casing (1), and the stator blades (7) are staggered behind the rotor blades (3); the shaftless pump pushing mechanism (4) comprises a shell (41), a fixed bearing (42), a motor component (43) and a shaftless blade component (44), wherein an annular groove is processed on the inner wall of the shell (41), and the fixed bearing (42), the motor component (43) and the fixed bearing (42) are sequentially clamped in the annular groove to form an integrated whole; the motor assembly (43) comprises a motor stator (431) and a motor rotor (432), and the motor rotor (432) is sleeved in the motor stator (431) and can rotate freely; the shaftless blade assembly (44) and the motor assembly (43) are of an inseparable and synchronous rotating integrated structure, the shaftless blade assembly (44) comprises a rotating ring (441) and shaftless blades (442), the shaftless blades (442) are positioned on the inner side of the rotating ring (441) and form an integral structure with the rotating ring (441), the rotating ring (441) is sleeved in a fixed bearing (42), and the axial position of the rotating ring is determined by the fixed bearing (42), and the shaftless blade assembly is characterized in that: the shaftless pump pushing mechanism (4) is located between a row of rotor blades (3) and a row of stator blades (7), two side faces of a shell (41) of the shaftless pump pushing mechanism (4) are in threaded connection with the side face of a casing (1) through a connecting screw (6), the shaftless blades (442), the rotor blades (3) and the stator blades (7) jointly form a compressor stage, the direction of airflow generated when the shaftless blades (442) rotate in the same compressor stage is opposite to the direction of airflow generated by the rotor blades (3), and the mechanical energy generated when the shaftless pump pushing mechanism (4) rotates is smaller than the mechanical energy generated when the rotor blades (3) rotate.

2. The axial flow compressor as recited in claim 1, wherein: the blade profile of the shaftless blade (442) is bent towards the axis, so that the cascade flow channel of the shaftless blade (442) forms a diffusion channel.

3. The axial flow compressor as recited in claim 1, wherein: the shaftless pumping mechanism (4) is present in the first 4 stages of the compressor stages, i.e. a maximum of 4 are allowed.

4. The axial flow compressor as recited in claim 1, wherein: the casing (1) is connected with the shell (41), the face of being connected of casing (1) is processed and is had the screw thread via hole, and the face of being connected of shell (41) is processed and is had the screw hole, and the position one-to-one between screw thread via hole and the screw hole to along the solid of revolution center annular array equipartition that casing (1) and shell (41) constitute on connecting the face, quantity is according to casing (1) diameter size equipartition 50 ~ 150 inequality.

5. The axial flow compressor as recited in claim 1, wherein: the connecting screw (6) is an outer hexagonal connecting screw provided with a safety hole, and the safety hole is positioned on the hexagonal side face.

6. The axial flow compressor as recited in claim 1, wherein: the material of the motor rotor (432) is Co50Fe-W composite material.