CN212028109U

CN212028109U - Air cooling system of electric centrifugal air compressor

Info

Publication number: CN212028109U
Application number: CN202020528862.2U
Authority: CN
Inventors: 顾茸蕾; 王燕青
Original assignee: Hedwell Taicang Energy Technology Co ltd
Current assignee: Hedwell Taicang Energy Technology Co ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2020-11-27
Anticipated expiration: 2030-04-10

Abstract

The utility model discloses an air cooling system of an electric centrifugal air compressor, which comprises a flow mixer, a primary compressor, a valve A, a secondary compressor, an intercooler, a secondary air filter, a valve B, a three-way valve, a motor, a first compressed air pipe, a second compressed air pipe, a third compressed air pipe, a first cooled air pipe, a second cooled air pipe, a cooled exhaust pipe, a first exhaust pipe, a return air pipe and an exhaust main pipe; compressed air from the first-stage compressor enters a first compressed air pipe, a part of the compressed air at a branch point enters a first cooling air pipe, and the compressed air in the first cooling air pipe enters the motor for cooling through a valve A; compressed air from the secondary compressor enters a second compressed air pipe, enters an intercooler, exits from an outlet of the intercooler, enters a second cooling air pipe, is filtered by a second air filter, enters the motor and cools the motor. The utility model discloses use on electronic centrifugal air compressor machine, can realize better cooling effect to and better comprehensive efficiency.

Description

Air cooling system of electric centrifugal air compressor

Technical Field

The utility model relates to an electric air compressor machine field especially relates to an air cooling system of electric centrifugal air compressor machine.

Background

Hydrogen fuel cells are an efficient and clean power plant. The core system of the hydrogen fuel cell is its stack, and in addition to this, there are 4 main auxiliary systems to ensure the normal and efficient operation of the stack, including: a hydrogen supply system, a gas supply system, a water management system and a thermal management system. A centrifugal air compressor driven by a permanent magnet synchronous motor is generally used to provide compressed air. At present, the mainstream method for radiating the inside of a motor of an electric centrifugal air compressor is to use cold air as a medium to enter the inside of a motor shell for flowing so as to take away heat generated by high-speed operation of the motor and a bearing.

The existing internal cooling air mode can be divided into two categories, namely introducing external high-pressure air for cooling and arranging a cooling fan inside the motor to absorb fresh air of the environment to enter the motor shell for cooling.

The design of introducing outside high-pressure air cooling motor inside, the air after the two-stage compression, the temperature can rise, then a part of gas after the intercooler cooling, guide back to the inside of motor casing after the air cleaner and cool, at last the exhaust gas converges and arrives the total exhaust outlet of fuel cell stack. The main disadvantages are as follows: the temperature and pressure of the external cooling air cannot be adjusted once the geometric dimensions of the flow channel are fixed, which easily causes difficulty in simultaneously satisfying the requirement of the cooling air volume at high speed and the requirement of the cooling air volume at low speed.

The other cooling mode is to arrange a cooling fan inside the motor, and cool air around the motor is absorbed by the rotation of the cooling fan and enters the motor to be forcibly cooled, so that the defect is obvious, the length of the rotating shaft of the whole motor is increased by the additional cooling fan which needs to be added, the critical rotating speed of a rotor system is reduced, the highest allowable operating rotating speed of the motor with the same design is obviously reduced, and the pressure ratio and the flow of the air compressor are reduced. In addition, after the structure is complex, the cleanness degree of sucked air is ensured by installing independent air inlet filter and the like, the installation difficulty is increased, and the volume and the cost of the whole machine are obviously increased due to the additional impeller and the internal flow channel.

Therefore, those skilled in the art have made an effort to develop an air cooling system of an electric centrifugal air compressor, which can achieve the best cooling effect under different working conditions.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned defect of prior art, the utility model aims to solve the technical problem that the inside effectual cooling problem of motor of electric centrifugal air compressor machine.

In order to achieve the purpose, the utility model provides an air cooling system of an electric centrifugal air compressor, which comprises a flow mixer, a primary compressor, a valve A, a secondary compressor, an intercooler, a secondary air filter, a valve B, a three-way valve, a motor, a first compressed air pipe, a second compressed air pipe, a third compressed air pipe, a first cooling air pipe, a second cooling air pipe, a cooling exhaust pipe, a first exhaust pipe, a return air pipe and a main exhaust pipe; compressed air from the primary compressor enters the first compressed air pipe, a part of compressed air at a branch point enters the first cooling air pipe, and the compressed air in the first cooling air pipe enters the motor for cooling through the valve A; compressed air from the secondary compressor enters a second compressed air pipe, is cooled by the intercooler, enters a second cooling air pipe, is filtered by the second air filter, enters the motor and is cooled by the motor; and cooling air from the motor enters the flow mixer through the air return pipe, is mixed with fresh air in the flow mixer, and enters the primary compressor.

Furthermore, one end of the first compressed air pipe is connected with the air outlet of the primary compressor, and the other end of the first compressed air pipe is connected with the air inlet of the secondary compressor; the cooling air pipe is a branch pipe of the first compressed air pipe; the valve A is installed on the cooling air pipe I.

Further, the valve A adopts a one-way opening low-pass valve.

One end of the second compressed air pipe is connected with an air outlet of the secondary compressor, and the other end of the second compressed air pipe is connected with the intercooler; the intercooler is provided with two outlets which are respectively connected with the compressed air pipe III and the cooling air pipe II, and the other end of the cooling air pipe II is connected with the second air filter.

Furthermore, the valve B adopts a one-way opening high-pass valve.

Furthermore, one end of the cooling exhaust pipe is connected with a cooling air outlet of the motor, and the other end of the cooling exhaust pipe is connected with the three-way valve.

Furthermore, one end of the air return pipe is connected with the three-way valve, and the other end of the air return pipe is connected with the flow mixer.

Furthermore, one end of the first exhaust pipe is connected with the three-way valve, and the other end of the first exhaust pipe is connected with the exhaust main pipe.

Further, the three-way valve is provided with an inlet and two outlets, the inlet is connected with the cooling exhaust pipe, one outlet is connected with the air return pipe, and the other outlet is connected with the first exhaust pipe; and switching the opening of the two outlets of the three-way valve according to the cooling requirement.

Further, the flow mixer is a separate component or is integrated with the pressure shell of the primary compressor.

The utility model discloses simple structure does not influence other aspects performance and the design of former machine, and the cost-push is little, nevertheless can realize better cooling effect to and better comprehensive efficiency. The surge margin is improved by the cooperation of the mixer and the three-way valve, and the stability of the system is improved.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings, so as to fully understand the objects, the features and the effects of the present invention.

Drawings

Fig. 1 is a diagram of an air cooling system of an electric centrifugal air compressor according to a preferred embodiment of the present invention;

the air conditioner comprises a compressor body, a first air filter, a second air filter, a flow mixer, a first-stage compressor, a valve A, a second-stage compressor, a cooler, a valve B, a humidifier, a valve A, a valve B.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly understood and appreciated by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments, and the scope of the invention is not limited to the embodiments described herein.

As shown in fig. 1, an air cooling system of an electric centrifugal air compressor includes a flow mixer 2, a primary compressor 3, a valve a4, a secondary compressor 5, an intercooler 6, a secondary air filter 7, a valve B8, a three-way valve 9, a motor 13, a first compressed air pipe 14, a second compressed air pipe 15, a third compressed air pipe 16, a first cooling air pipe 17, a second cooling air pipe 18, a cooling exhaust pipe 19, a first exhaust pipe 20, a return air pipe 21 and an exhaust manifold 23. Fresh air is filtered by a first air filter 1 and enters a flow mixer 2, then enters a first-stage compressor 3 for compression, compressed air from an air outlet of the first-stage compressor 3 enters a second-stage compressor 5 for further compression through a first compressed air pipe 14, compressed air from an air outlet of the second-stage compressor 5 enters an intercooler 6 for cooling through a second compressed air pipe 15, then is sent to a humidifier 10 for humidification through a third compressed air pipe 16, finally enters a galvanic pile 11 for reaction, and generated waste gas containing gaseous and liquid water enters the humidifier 10 for humidifying inlet air and then is discharged through a back pressure valve 12, a second exhaust pipe 22 and an exhaust manifold 23.

A valve A4 is installed on the branch pipe cooling air pipe I17 of the compressed air pipe I14, a valve A4 adopts a one-way open low-pass valve, the valve A is kept in an open state before the pressure is lower than a closed calibration pressure, and in the open state, compressed air can pass through and enter the motor 13 to cool the motor 13; valve a4 closes after the nominal pressure has been closed, and this compressed air cannot enter the motor 13 for cooling through valve a 4. Because the state that pressure is low, the lower operating mode of corresponding motor 13 work load, the rotational speed is lower this moment, and the inside of motor 13 is not serious to generate heat, adopts the inside of the compressed air cooling motor 13 that first grade compressor 3 came out, is fit for to the performance influence to whole air compressor machine is less. This is the first cooling circuit.

The compressed air from the outlet of the secondary compressor 5 has a higher temperature and a higher pressure than the compressed air in the first cooling air pipe 17 and must be cooled before it can be used to cool the motor 13. The intercooler 6 is arranged on the second compressed air pipe 15, the intercooler 6 is provided with two outlets, one outlet is connected with the third compressed air pipe 16, and the other outlet is connected with the second cooling air pipe 18. The compressed air from the air outlet of the secondary compressor 5 enters the intercooler 6 through the second compressed air pipe 15, and a part of the cooled compressed air enters the second air filter 7 through the second cooling air pipe 18, enters the motor 13 through the valve B8 after being filtered, and cools the motor 13. This is a second cooling circuit that cools the electric machine 13. The valve B8 adopts a one-way opening high-pass valve, is closed under low pressure and can be opened only after reaching the opening calibration pressure. Only if the valve B8 is open, the path of compressed air can pass through and into the motor 13 and cool the motor 13. The opening pressure of valve B8 is associated with (and not the same as) the closing pressure setting of valve a4, such that valve B8 is closed when valve a4 is open and valve B8 is open when valve a4 is closed. When the valve B8 is closed, the compressed air from the air outlet of the secondary compressor 5 is completely introduced into the compressed air pipe three 16 in the intercooler 6, and is completely used for the reaction of the galvanic pile 11, and the temperature of the compressed air is not required to be very low due to the reaction of the galvanic pile 11, so that the cooling temperature of the intercooler 6 under the working condition can be set to be higher than the ventilation working condition of the two outlets, the energy consumption of the intercooler 6 can be saved, the higher temperature is also helpful for improving the humidity of the air in the humidifier 10, and the working efficiency of the galvanic pile 11 is further improved.

The cooling air entering the motor 13 takes away the redundant heat of the motor 13, and the temperature of the motor 13 is kept not to exceed the limit. The temperature of the air leaving the motor 13 rises and the pressure drops, entering the three-way valve 9 through the cooling exhaust pipe 19. The three-way valve 9 can adjust the flow rate of the cooling air as required. Under the working conditions of low motor power and low heat generation at medium and low rotating speeds, the compressed air flows into the air return pipe 21 and then enters the mixer 2, and finally flows back to the first-stage compressor 3, so that the compressed air can be compressed by using the compressed energy of the compressed air, the compressed energy consumption of the first-stage compressor 3 is reduced, the surge margin of the centrifugal compressor at the medium and low rotating speeds is widened, and the reliability of the compressor is improved. The three-way valve 9 can also switch the opening direction at medium and high rotation speed according to the requirement, and the cooled air with higher temperature is guided to the first exhaust pipe 20 and finally enters the exhaust manifold 23. This helps to reduce the back pressure of the cooling circuit and to avoid higher temperature air from affecting the operation of the primary and

secondary compressors

3 and 5.

The mixer 2 is provided to reduce the effect on the performance of the primary compressor 3 when the returning cooling air flows to the primary compressor 3, and the mixer 2 allows the fresh air and the returning cooling air to be uniformly mixed. The three-way valve 9 is used for increasing residual air backflow, the surge margin is improved through the matching effect of the flow mixer 2 and the three-way valve 9, the system stability is improved, and the energy consumption of the compressor is reduced through the compression capacity of cooling air under the medium-low working condition. The mixer 2 can be separated into separate parts or can be integrally formed with the pressure shell of the first-stage compressor 3.

As the rotation speed of the electric air compressor is increased, the compression work of the primary compressor 3 is increased, the temperature of the gas in the compressed air pipe 14 is increased, and thus the cooling effect of the motor 13 is deteriorated. At this time, the cooling requirement of the bearings of the motor 13 is increased due to the increase of the load and the rotation speed. It can be set that now the valve a is closed and the valve B is opened, and the low-temperature compressed air coming out of the secondary compressor 5 and cooled by the intercooler 6 is obtained for cooling the motor 13. The relationship between the temperature and the pressure of the compressed air can be established according to the gas equation of state, and the valve A with the preset calibrated pressure is closed, and meanwhile, the valve B reaches the opening pressure. And the circulation capacity of the valve A and the valve B and the circulation capacity of the corresponding two-way pipe are designed in advance, so that the requirement of the motor 13 on cooling air is met, the whole operation working condition reaches the optimal effect, and the system efficiency is further optimized.

The foregoing has described in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the teachings of this invention without undue experimentation. Therefore, the technical solutions that can be obtained by a person skilled in the art through logic analysis, reasoning or limited experiments based on the prior art according to the concepts of the present invention should be within the scope of protection defined by the claims.

Claims

1. An air cooling system of an electric centrifugal air compressor is characterized by comprising a flow mixer, a primary compressor, a valve A, a secondary compressor, an intercooler, a second air filter, a valve B, a three-way valve, a motor, a first compressed air pipe, a second compressed air pipe, a third compressed air pipe, a first cooling air pipe, a second cooling air pipe, a cooling exhaust pipe, a first exhaust pipe, a return air pipe and an exhaust main pipe; compressed air from the primary compressor enters the first compressed air pipe, a part of compressed air at a branch point enters the first cooling air pipe, and the compressed air in the first cooling air pipe enters the motor for cooling through the valve A; compressed air from the secondary compressor enters a second compressed air pipe, is cooled by the intercooler, enters a second cooling air pipe, is filtered by the second air filter, enters the motor and is cooled by the motor; and cooling air from the motor enters the flow mixer through the air return pipe, is mixed with fresh air in the flow mixer, and enters the primary compressor.

2. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein one end of the first compressed air pipe is connected to the air outlet of the primary compressor, and the other end is connected to the air inlet of the secondary compressor; the cooling air pipe is a branch pipe of the first compressed air pipe; the valve A is installed on the cooling air pipe I.

3. The air cooling system of claim 2, wherein the valve a is a one-way low-pass valve.

4. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein one end of the second compressed air pipe is connected to the air outlet of the secondary compressor, and the other end is connected to the intercooler; the intercooler is provided with two outlets which are respectively connected with the compressed air pipe III and the cooling air pipe II, and the other end of the cooling air pipe II is connected with the second air filter.

5. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein the valve B is a one-way open high-pass valve.

6. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein one end of the cooling air discharging pipe is connected to the cooling air outlet of the motor, and the other end is connected to the three-way valve.

7. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein one end of the air returning pipe is connected to the three-way valve, and the other end is connected to the flow mixer.

8. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein one end of the first exhaust pipe is connected to the three-way valve, and the other end is connected to the exhaust manifold.

9. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein said three-way valve has an inlet and two outlets, said inlet is connected to said cooling exhaust pipe, one outlet is connected to said return air pipe, and the other outlet is connected to said exhaust pipe one; and switching the opening of the two outlets of the three-way valve according to the cooling requirement.

10. The air cooling system of an electric centrifugal air compressor as claimed in claim 1, wherein said flow mixer is a separate component or is integrated with a pressure shell of said primary compressor.