CN112460048A

CN112460048A - Bipolar centrifugal air compressor

Info

Publication number: CN112460048A
Application number: CN202011546987.9A
Authority: CN
Inventors: 邢子义; 王升科; 李殿赟; 谢元豪
Original assignee: Yantai Dongde Industrial Co Ltd
Current assignee: Yantai Dongde Industrial Co Ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-03-09

Abstract

The utility model provides a bipolar centrifugal air compressor, include casing and main shaft by outer to interior setting gradually, the main shaft outside is equipped with motor stator, inside is equipped with motor rotor, the casing both ends are equipped with one-level compressor arrangement and second grade compressor arrangement, communicate through middle pipeline between one-level compressor arrangement and the second grade compressor arrangement, bipolar centrifugal air compressor still includes cooling system, cooling system includes water cooling plant and air cooling plant, outside air cooling plant is including the gaseous precooling passageway that sets up in the water cooling plant outside, precooling passageway rear side upper end is equipped with first air inlet, precooling passageway front side lower extreme is equipped with the second air inlet, the second air inlet pierces through the casing, the casing is located precooling passageway rear side position is equipped with the gas outlet, introduce casing subassembly with part compressed gas through middle pipeline in, get into the casing again after tentatively cooling through the water cooling plant and realize to motor, The main shaft, the radial bearing and the thrust bearing are cooled, and the service life of the air compressor is prolonged.

Description

Bipolar centrifugal air compressor

Technical Field

The invention relates to the technical field of hydrogen fuel cell engines, in particular to a bipolar centrifugal air compressor.

Background

The development of new energy fuel cell automobiles is considered to be an important link of traffic energy power transformation at present and is paid much attention. Proton exchange membrane fuel cells are currently the most mature representative of the fuel cell family. The device takes hydrogen and air (oxygen in the air) as fuel to generate electrochemical reaction, and directly converts the chemical energy of the fuel into electric energy to generate water. The energy-saving automobile engine has the advantages of no pollution, high efficiency, wide application, low noise, quick start at room temperature, capability of quickly supplementing energy, modular structure and the like, and is likely to become one of main power sources of automobiles following the traditional internal combustion engine.

In order to ensure the normal operation of the fuel cell engine, the engine generally needs auxiliary systems such as a hydrogen supply subsystem, an air supply subsystem and a circulating water cooling management subsystem. A number of studies have shown that high pressure, high flow air supply has a significant effect on improving the power output of existing fuel cell engines. Therefore, before air enters the engine, the air compressor is an energy conversion device for realizing the purpose, and is one of important parts of an air supply system of the fuel cell engine.

At present, a centrifugal air compressor is generally designed in a motor direct-drive mode, a motor rotor and a main shaft are made into an integrated structure, a centrifugal impeller is fixedly connected to the end of the main shaft, and the impeller is arranged in a volute. Under the super-high speed rotation of the motor rotor, the impeller drives gas to rotate at high speed, the gas and the volute interact to generate high-pressure and large-flow air which is supplied to a fuel cell engine for the generation of electrochemical reaction inside a fuel cell stack, and the bearing supports the main shaft-impeller integrated rotating part to rotate at high speed.

The direct-drive centrifugal air compressor is generally driven by a motor, consumes the power of an automobile engine with a fuel cell and is about 15-20% of the total power output of the engine with the fuel cell. Therefore, in order to improve the effective power output of the engine and reduce the power consumption of the air compressor, the high-speed and high-efficiency air compressor technology draws extensive attention.

As the speed of the centrifugal air compressor increases, the rotor is subjected to a greater and greater centrifugal force. The permanent magnet material in the rotor generally has the compression strength of about 1000MPa, the tensile strength of about 80MPa, and the rotor has the characteristics of compression resistance and no tensile strength, and the rotor with smaller diameter is generally adopted in the design of the air compressor rotor, so that the damage of high-speed centrifugal force to the permanent magnet is reduced.

In addition, the electrochemical reaction of the fuel cell is carried out under certain temperature, humidity and gas pressure, and the reaction is also accompanied with certain heat release, so that the air in the air supply system of the fuel cell engine has the characteristics of high temperature, high humidity, high pressure, large flow and no oil, the catalytic action of the fuel cell catalyst is reduced due to the introduction of oil, and the power output of the fuel cell engine is greatly reduced.

Meanwhile, in order to improve the pressure and flow of output air, a centrifugal air compressor usually adopts a rotating speed control implementation mode of ultrahigh rotating speed (above 80000 rpm), and the existing traditional rolling and sliding oil lubrication bearing is difficult to meet the requirements, so that the requirements of an oil-free working environment of a fuel cell engine are not met, and the rotating speed of a rotor-main shaft is reduced and the friction loss is increased due to the existence of mechanical friction. Even if special bearings are adequate, they can also cause problems with rotor thermal problems and rotor dynamic stability. And secondly, the danger of damage of supporting parts such as bearings and the like is caused, and the difficulty of fault monitoring and diagnosis is increased. In addition, the ultra-high speed rotor also presents heat dissipation and cooling problems, which, taken together, place greater demands on the use of bearings that support the ultra-high speed rotation of the spindle-impeller, requiring comprehensive consideration and resolution in the particular centrifugal air compressor design.

Disclosure of Invention

The invention aims to solve the problems and provides a bipolar centrifugal air compressor which comprises a shell and a main shaft which are sequentially arranged from outside to inside, wherein a motor stator is arranged on the outer side of the main shaft, a motor rotor is arranged inside the main shaft, a primary compression device and a secondary compression device are arranged at two ends of the shell, the primary compression device is communicated with the secondary compression device through an intermediate pipeline,

a first-stage diffuser and a second-stage diffuser are respectively arranged between two ends of the shell and the first-stage compression device and the second-stage compression device, a bearing mounting seat is arranged at the position, close to the first-stage diffuser, of the shell, a front bearing chamber is arranged on the inner side of the bearing mounting seat, a rear bearing chamber is arranged on the inner side of the second-stage diffuser, radial bearings are sleeved between the main shaft and the front bearing chamber and between the main shaft and the rear bearing chamber, and the main shaft penetrates through the first-stage diffuser and the second-stage diffuser and is fixedly connected with the first-stage compression device;

the first-stage compression device and the second-stage compression device both comprise impellers and volutes, and the first-stage volute and the second-stage volute are hermetically connected with two ends of the shell; the primary impeller and the secondary impeller are fixedly connected with two ends of the main shaft through locking nuts respectively, a thrust disc is sleeved on the main shaft close to one end of the primary impeller, the thrust disc is arranged between the primary diffuser and the bearing mounting seat and is fixedly connected with the primary impeller, and air foil bearings are arranged on two sides of the thrust disc;

bipolar centrifugal air compressor machine still includes cooling system, cooling system includes water cooling plant and air cooling plant, water cooling system is for locating heliciform coolant liquid runner in the casing, be equipped with coolant liquid access joint and coolant liquid water swivel on the casing that heliciform coolant liquid runner head end and end correspond, cold charge plant is including setting up the gas precooling passageway in the water cooling plant outside, precooling passageway rear side upper end is equipped with first air inlet, first air inlet pass through the pipeline with first air conditioning articulate on the intermediate pipeline, precooling passageway front side lower extreme is equipped with the second air inlet, the second air inlet pierces through the casing, the casing is located precooling passageway rear side position is equipped with the gas outlet.

Furthermore, a step platform is arranged on one side, close to the first impeller, of the motor main shaft.

Furthermore, a convex ring is arranged at the center of the thrust disc, the width of the convex ring is the same as that of the step platform, the convex ring is sleeved in the step platform and extends into the first-stage diffuser together, and the convex ring is fixedly connected with the first-stage impeller.

Further, a gasket is arranged between the thrust disc and the air foil bearing.

Furthermore, the connection surfaces of the first-stage volute and the second-stage volute and the shell are all planes without radian.

Further, the outer side of the radial bearing is longitudinally provided with an air foil.

Further, the second air inlet is formed between the first-stage diffuser and the bearing mounting seat.

Furthermore, a gap is formed between the thrust disc and the first-stage diffuser and between the thrust disc and the bearing mounting seat.

Further, a gap is formed between the two ends of the motor spindle and the radial bearing.

Further, spring retainer rings are arranged at the tail ends of the front bearing chamber and the rear bearing chamber.

Further, the main shaft comprises a front end main shaft and a rear end main shaft, the two ends of the front end main shaft and the two ends of the rear end main shaft which are fixedly connected are respectively provided with a through assembly vent hole, a gap is reserved between the front end main shaft and the rear end main shaft, a cavity is arranged in the rear end main shaft, and a motor rotor is arranged in the cavity.

The invention has the advantages that:

(1) the motor, the shell and the main shaft are integrally designed, so that the size and the weight of the whole machine are reduced, and the abrasion between the connecting surfaces caused by the split shell is reduced by integrally forming the shell.

(2) The two-stage semi-open type impeller is connected in series through the middle pipeline, and the low-flow high-pressure ratio is realized. The gas mass flow rate reaches at least 300g/s, the compression ratio reaches 4, and the rotating speed reaches 50000-110000 rpm.

(3) Axial thrust of the two-stage impellers is offset, and the axial force applied by the thrust bearing is reduced. Radial and axial air bearings are adopted, and a gas film is formed by high-pressure gas generated by the bearings, so that the friction between the bearings and a rotor is reduced, the high-speed direct drive of a gas suspension motor is formed, the mechanical loss is reduced, and the service life of the air compressor is prolonged.

(4) Through setting up cooling system on the casing, water cooling system has realized the cooling to casing and motor stator, introduces the casing subassembly with partial compressed gas through middle pipeline in, get into the casing again after tentatively cooling down through water cooling plant and realize motor, main shaft, journal bearing and thrust bearing refrigerated, improve the life of air compressor machine.

Drawings

FIG. 1 is an external structural view of the present invention;

FIG. 2 is a sectional view of the internal structure of the present invention;

FIG. 3 is a detail view of the thrust disc of FIG. 2;

fig. 4 is a view showing the structure of the casing of the present invention.

Drawing reference number

Casing (1), main shaft (2), motor stator (3), electric motor rotor (4), middle pipeline (5), one-level diffuser (6), second grade diffuser (7), bearing mount pad (8), spring retainer ring (9), rear end main shaft (10), journal bearing (11), one-level spiral case (12), second grade spiral case (13), one-level impeller (14), second grade impeller (15), thrust disc (16), air foil bearing (17), heliciform coolant liquid runner (18), coolant liquid access joint (19), coolant liquid water connectors (20), precooling passageway (21), first air inlet (22), first air conditioning connects (23), second air inlet (24), gas outlet (25), assembly air vent (26), terrace stage (27), bulge loop (28), gasket (29), front end main shaft (30).

Detailed Description

The following detailed description of the present invention will be made in conjunction with the accompanying drawings, but the following examples are merely illustrative of preferred embodiments, which are provided to assist understanding of the present invention, and are not to be construed as limiting the present invention.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout.

The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Example 1

The invention discloses a bipolar centrifugal air compressor as shown in figures 1-4, which comprises a shell 1 and a main shaft 2 which are arranged from outside to inside in sequence, wherein a motor stator 3 is arranged on the outer side of the main shaft 2, a motor rotor 4 is arranged inside the main shaft 2, a primary compression device and a secondary compression device are arranged at two ends of the shell 1, the primary compression device and the secondary compression device are communicated through an intermediate pipeline 5,

1 both ends of casing with be equipped with one-level diffuser 6 and second grade diffuser 7 between one-level compression device and the second grade compression device respectively, casing 1 is close to 6 departments of one-level diffuser and is equipped with bearing mount pad 8, 8 inboards of bearing mount pad are equipped with the front bearing room, 7 inboards of second grade diffuser are equipped with the rear bearing room, main shaft 2 with all the cover is equipped with radial bearing 11 between front bearing room and the rear bearing room, front bearing room and rear bearing room end are equipped with circlip 9 and are used for blockking the bearing.

The outer side of the radial bearing 11 is longitudinally provided with an air foil, and the main shaft 2 passes through the first-stage diffuser 6 and the second-stage diffuser 7 to be fixedly connected with the first-stage compression device and the second-stage compression device;

the first-stage compression device and the second-stage compression device both comprise impellers and volutes, and the first-stage volute 12 and the second-stage volute 13 are hermetically connected with two ends of the shell 1; the primary impeller 14 and the secondary impeller 15 are respectively fixedly connected with two ends of the main shaft 2 through locking nuts, a thrust disc 16 is sleeved on the main shaft 2 close to one end of the primary impeller 14, the thrust disc 16 is arranged between the primary diffuser 6 and the bearing mounting seat 8 and is fixedly connected with the primary impeller 14, air foil bearings 17 are arranged on two sides of the thrust disc 16, and a gasket 29 is arranged between the thrust disc 16 and the air foil bearings 17;

the bipolar centrifugal air compressor also comprises a cooling system, the cooling system comprises a water cooling device and an air cooling device, the water cooling system is a spiral cooling liquid flow channel 18 arranged in the shell 1, a cooling liquid inlet joint 19 and a cooling liquid outlet joint 20 are arranged on the shell 1 corresponding to the head end and the tail end of the spiral cooling liquid flow channel 18, the air cooling device comprises a gas pre-cooling channel 21 arranged outside the water cooling device, a first air inlet 22 is arranged at the upper end of the rear side of the pre-cooling channel 21, the first air inlet 22 is connected with a first cold air joint 23 on the middle duct 5 through a duct, a second air inlet 24 is arranged at the lower end of the front side of the precooling channel 21, the second air inlet 24 is arranged between the first-stage diffuser 6 and the bearing mounting seat 8, the second air inlet 24 penetrates through the housing 1, and an air outlet 25 is formed in the rear side of the pre-cooling channel 21 of the housing 1.

A step platform 27 is arranged on one side of the motor main shaft 2 close to the first impeller. A convex ring 28 is arranged at the center of the thrust disc 16, the width of the convex ring 28 is the same as that of the step platform 27, and the convex ring 28 is sleeved in the step platform 27 and extends into the step platform 27 together.

The connection surfaces of the first-stage volute 12 and the second-stage volute 13 and the shell 1 are both planes without radian.

A gap is formed between the thrust disc 16 and the first-stage diffuser 6 and between the thrust disc and the bearing mounting seat 8, and a gap is formed between two ends of the motor spindle 2 and the radial bearing 11.

The main shaft 2 comprises a front end main shaft 30 and a rear end main shaft 10, the front end main shaft 30 and the rear end main shaft 10 are fixedly connected with two ends respectively provided with a through assembly vent hole 26, a gap is reserved between the front end main shaft 30 and the rear end main shaft 10, a cavity is arranged in the rear end main shaft 10, and a motor rotor 4 is arranged in the cavity.

The primary back plate and the secondary back plate 12 are fixedly connected with the shell 1 through bolts.

When the invention is used, the water-saving agent is added into the water,

the main shaft is driven to operate through the motor, the two-stage impeller is driven to operate, axial force can be generated in the axial direction when the main shaft rotates, the two-stage impellers are connected in series, partial axial force of the main shaft in the axial direction can be offset, a radial bearing and a thrust bearing which are arranged on the main shaft generate high-pressure gas to form a gas film when the main shaft operates at a high speed, friction between the bearing and a rotor is reduced, the gas film generated by the thrust bearing can play a buffering role when the main shaft moves leftwards and rightwards, the gas film generated by the thrust bearing on the left side can prevent the main shaft from moving leftwards and vice versa when the main shaft moves rightwards, and collision between left-right movement and volute of.

Meanwhile, a water cooling system is arranged outside the shell, compressed gas is introduced from the middle pipeline to enter the cavity of the shell, and the compressed gas is cooled along a set gas flow passage and flows in the shell to cool the motor stator, the main shaft and the bearing in an air cooling manner, so that the cooling effect is outstanding, the deformation or damage of parts in the shell which rotate at high speed under high temperature is avoided, and the service life of the air compressor is prolonged.

Embodiments of the present invention, it should be understood that the above-described embodiments are illustrative and should not be construed as limiting the present invention, and that those skilled in the art can make changes, modifications, substitutions and alterations to the above-described embodiments without departing from the principle and spirit of the present invention, and that all such changes in combination are intended to be within the scope of the present invention.

Claims

1. A bipolar centrifugal air compressor comprises a shell (1) and a main shaft (2) which are sequentially arranged from outside to inside, wherein a motor stator (3) is arranged on the outer side of the main shaft (2), a motor rotor (4) is arranged inside the main shaft, a primary compression device and a secondary compression device are arranged at two ends of the shell (1), the primary compression device and the secondary compression device are communicated through an intermediate pipeline (5), and the bipolar centrifugal air compressor is characterized in that,

a first-stage diffuser (6) and a second-stage diffuser (7) are respectively arranged between two ends of the shell (1) and the first-stage compression device and the second-stage compression device, a bearing mounting seat (8) is arranged at a position, close to the first-stage diffuser (6), of the shell (1), a front bearing chamber is arranged on the inner side of the bearing mounting seat (8), a rear bearing chamber is arranged on the inner side of the second-stage diffuser (7), radial bearings (11) are sleeved between the main shaft (2) and the front bearing chamber and between the main shaft and the rear bearing chamber, and the main shaft (2) penetrates through the first-stage diffuser (6) and the second-stage diffuser (7) to be fixedly connected with the first-stage compression device and;

the first-stage compression device and the second-stage compression device both comprise impellers and volutes, and the first-stage volute (12) and the second-stage volute (13) are hermetically connected with two ends of the shell (1); the primary impeller (14) and the secondary impeller (15) are respectively fixedly connected with two ends of the main shaft (2) through locking nuts, a thrust disc (16) is sleeved on the main shaft (2) close to one end of the primary impeller (14), the thrust disc (16) is arranged between the primary diffuser (6) and the bearing mounting seat (8) and is fixedly connected with the primary impeller (14), and air foil bearings (17) are arranged on two sides of the thrust disc (16);

the bipolar centrifugal air compressor further comprises a cooling system, the cooling system comprises a water cooling device and an air cooling device, the water cooling system is arranged on the shell (1) and comprises a spiral cooling liquid flow channel (18), a cooling liquid inlet joint (19) and a cooling liquid outlet joint (20) are arranged on the shell (1) corresponding to the head end and the tail end of the spiral cooling liquid flow channel (18), the air cooling device comprises an external air cooling device, the external air cooling device comprises a gas pre-cooling channel (21) arranged on the outer side of the water cooling device, a first air inlet (22) is arranged at the upper end of the rear side of the pre-cooling channel (21), the first air inlet (22) is connected with a first air cooling joint (23) on the intermediate pipeline (5) through a pipeline, a second air inlet (24) is arranged at the lower end of the front side of the pre-cooling channel (21), and the second air inlet (24) penetrates through the shell (1, and an air outlet (25) is formed in the rear side part of the housing (1) positioned on the precooling channel (21).

2. The bipolar centrifugal air compressor of claim 1, wherein: one side of the motor spindle (2) close to the first impeller is inwards provided with a step platform (27).

3. The bipolar centrifugal air compressor of claim 2, wherein: thrust disc (16) center department is equipped with bulge loop (28), bulge loop (28) width with step platform (27) width is the same, bulge loop (28) cover in together stretch into one-level diffuser (6) in step platform (27), bulge loop (28) with one-level impeller (14) fixed connection.

4. The bipolar centrifugal air compressor of claim 1, wherein: a gasket (29) is arranged between the thrust disc (16) and the air foil bearing (17).

5. The bipolar centrifugal air compressor of claim 1, wherein: the connection surfaces of the first-stage volute (12) and the second-stage volute (13) and the shell (1) are all planes without radian.

6. The bipolar centrifugal air compressor of claim 1, wherein: the radial bearing (11) is longitudinally composed of a plurality of air foils on the outer side.

7. The bipolar centrifugal air compressor of claim 1, wherein: the second air inlet (24) is arranged between the first-stage diffuser (6) and the bearing mounting seat (8).

8. The bipolar centrifugal air compressor of claim 1, wherein: a gap is formed between the thrust disc (16) and the first-stage diffuser (6) and between the thrust disc and the bearing mounting seat (8), and a gap is formed between the two ends of the motor spindle (2) and the radial bearing (11).

9. The bipolar centrifugal air compressor of claim 1, wherein: spring retainer rings (9) are arranged at the tail ends of the front bearing chamber and the rear bearing chamber.

10. The bipolar centrifugal air compressor of claim 1, wherein: the main shaft (2) comprises a front end main shaft (30) and a rear end main shaft (10), and assembling vent holes (26) are formed in two ends of the fixed connection of the front end main shaft (30) and the rear end main shaft (10) and used for ventilation during assembling.