CN213807963U

CN213807963U - Air compression system with turbo expander

Info

Publication number: CN213807963U
Application number: CN202022581443.8U
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: 2020-11-10
Filing date: 2020-11-10
Publication date: 2021-07-27
Anticipated expiration: 2030-11-10

Abstract

The utility model discloses an air compression system with turboexpander, include: a compressor; the air conditioner and the humidifier are sequentially connected with the exhaust port of the compressor, and the humidifier is connected with the fuel cell; compressed gas discharged by the compressor enters the fuel cell after sequentially passing through the intercooler and the humidifier; a motor disposed coaxially with the compressor; the turbine expander is coaxial with the motor, and the turbine expander and the compressor are respectively positioned on two sides of the motor; the turboexpander is configured to drive the compressor together with the motor under the drive of the air discharged from the fuel cell; and the sealing air path is connected between the motor and the turbo expander from an air outlet of the intercooler, and can prevent air in the turbo expander from entering the motor. The utility model discloses an air compression system has avoided carrying out rust-resistant treatment to the easy rust component of motor, has reduced manufacturing cost.

Description

Air compression system with turbo expander

Technical Field

The utility model relates to a fuel cell field especially relates to an air compression system with turbo expander for supply with air for fuel cell.

Background

The fuel cell is a high-efficient clean new energy power system, the air compressor compresses the air, then send into the fuel cell negative pole, the air carries on the chemical reaction with the hydrogen of positive pole, the product that produces is electric energy and water, still some heat discharges to the atmosphere along with unnecessary air, except there is not other products that pollute the environment in addition, so the fuel cell is very clean environmental protection, all countries are promoting the development and popularization of hydrogen fuel cell power system vigorously at present.

The air compressor special for the fuel cell is a very important part in a hydrogen fuel cell power system, and is used for providing compressed air with certain pressure and certain flow for the cathode of the fuel cell so as to meet the requirement of the fuel cell reaction on oxygen in the air. Since the lubricating oil film greatly affects the service life of the fuel cell, in order to prevent the compressed air from containing lubricating oil, the air compressor needs to operate in an oil-free environment, the operating speed of the air compressor is relatively high, and the rotating speed per minute can reach hundreds of thousands of revolutions. At present, the fuel cell air compressor has single-stage compression and two-stage compression. The single-stage compression is that a motor drives a pinch roller, and the two-stage compression is that a motor drives two pinch rollers, and one is the low pressure level, and another is the high-pressure level, and high-pressure level and low-pressure level are the series connection, and the air reentries the high-pressure level after the low pressure level compression and carries out the second compression, so the air pressure and the flow that two-stage compressor obtained are higher than single-stage compressor, and the fuel cell power range of applicable is bigger.

However, in the two-stage compressor, only a part of oxygen in the compressed air entering the fuel cell stack participates in the reaction, and other compressed air is discharged to the atmosphere, which easily causes the energy carried by the part of high-pressure gas to be wasted.

In the prior art, some have used an air compressor with a turbo expander to direct high pressure air from the fuel cell to a turbine mounted coaxially with the motor to blow the turbine into rotation. Rotation of the turbine assists the motor in driving the compressor. However, this also causes a problem that moisture in the high-pressure air discharged from the fuel cell contains a certain amount of water vapor, and the moisture in the high-pressure air can enter the motor casing through a gap between the turbine and the click wheel, which easily causes rusting of parts of the motor, such as the stator, the rotor, and the bearing. In order to solve this problem, the prior art adopts a means of performing rust prevention treatment on parts which are easy to rust in the motor, but the treatment method causes high cost.

Therefore, those skilled in the art have been devoted to developing an air compression system with a turbo expander capable of preventing moisture in high-pressure air discharged from a fuel cell from entering into a motor without performing rust prevention treatment on a rust-prone part of the motor by a seal structure provided between the turbo expander and the motor.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned defects in the prior art, the technical problem to be solved in the present invention is how to prevent the water vapor in the gas blown to the turbine from the fuel cell from entering the motor casing through the gap between the turbine and the motor casing, resulting in making the motor rust easily.

To achieve the above object, the present invention provides an air compression system with a turboexpander, comprising:

a compressor;

an intercooler and a humidifier sequentially connected to an exhaust port of the compressor, the humidifier being configured to be connected to a fuel cell; the compressed gas discharged by the compressor sequentially passes through the intercooler and the humidifier and then enters the fuel cell;

a motor disposed coaxially with the compressor, the motor configured to be capable of driving the compressor;

the turbo expander is coaxially arranged with the motor, and the turbo expander and the compressor are respectively positioned on two sides of the motor; the turboexpander is configured to drive the compressor with the motor under the drive of the air discharged from the fuel cell;

a sealed air passage connected between the motor and the turbo expander from an air outlet of the intercooler, the sealed air passage configured to prevent air in the turbo expander from entering the motor.

Further, the compressor comprises a first compressor and a second compressor which are connected in series, and the outlet pressure of the first compressor is smaller than that of the second compressor.

Further, the back surface of the pinch roller of the first compressor is adjacent to the back surface of the pinch roller of the second compressor.

Further, the first compressor and the second compressor are both centrifugal compressors.

Furthermore, a channel for gas to pass through is sequentially arranged on the shell of the motor, the bearing seat of the motor and the back plate of the turboexpander, and the channel is communicated with the sealing gas circuit.

Further, two sets of piston rings are provided between the housing of the turboexpander and the back plate of the turboexpander.

Further, the channel is located at a position intermediate the two sets of piston rings.

Further, the gas pressure within the sealed gas path is greater than the gas pressure within the turboexpander.

Further, the cooling air path is connected to the motor from the air outlet of the intercooler and used for cooling the motor.

Further, the air filter is connected with an air inlet of the compressor, so that air enters the compressor after passing through the air filter.

Further, the air compression system is configured to be powered by the fuel cell.

Compared with the prior art, the utility model has the advantages of it is following:

the utility model provides an air compression system sets up seal structure between turbo expander and air compressor machine, prevents inside humid air entering motor casing in the turbo expander through highly-compressed air, has avoided carrying out rust-resistant treatment to the easy rust part of motor, has reduced manufacturing cost. Furthermore, the utility model provides a simple structure realizes easily, to current air compressor machine system of not doing rust-resistant treatment, can reach rust-resistant effect through simple transformation after, has very big economic value.

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 block schematic diagram of an air compression system with a turboexpander in accordance with a preferred embodiment of the present invention;

fig. 2 is a schematic view of a sealed gas circuit structure of an air compression system with a turbo expander according to a preferred embodiment of the present invention.

Wherein, wherein: the method comprises the following steps of 1-a bearing seat, 2-a turbine back plate, 3-a turbine, 4-a centering sleeve, 5-a rotating shaft, 6-a motor shell, 7-a vent hole, 8-a piston ring, 9-an intercooler, 10-an air filter, 11-a first compressor, 12-a second compressor, 13-a motor, 14-a turbine expander, 15-a sealing gas circuit, 16-a cooling gas circuit, 17-a fuel cell and 18-a humidifier.

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.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

As shown in fig. 1, the utility model provides an air compressor with expander includes: the air conditioner comprises a compressor, a motor 13, a turbo expander 14, an intercooler 9, a humidifier 18 and a sealed air path 15. The compressor, the motor 13 and the turbine expander 14 are sequentially and coaxially connected, and the compressor and the turbine expander 14 are respectively positioned on two sides of the motor 13; the exhaust port of the compressor is sequentially connected with an intercooler 9 and a humidifier 18, and is finally connected with a fuel cell 17; the exhaust port of the fuel cell 17 is connected to the turbo expander 14. A branch connected with a sealing air path 15 is arranged at an exhaust port of the intercooler 9, and the sealing air path 15 is connected between the turbo expander 14 and the motor 13. Since the gas in the sealed gas path 15 is compressed by the compressor and has a pressure higher than that of the gas in the turbo expander 14, when the sealed gas path 15 is connected to a position between the turbo expander 14 and the motor 13, it is possible to prevent the wet air in the turbo expander 14 from entering the motor case 6 through a gap between connection points of the turbo expander 14 and the motor 13.

With continued reference to fig. 1, the operation of the air compression system with turboexpander 14 of the present invention is as follows:

after passing through the air filter 10, the outside air is at the same atmospheric pressure as the atmospheric pressure, and is low-pressure air. The low-pressure air enters the compressor and becomes high-pressure air after being compressed by the compressor. The high-pressure air is discharged from the exhaust port of the compressor, enters the intercooler 9, is discharged from the exhaust port of the intercooler 9, enters the humidifier 18, and finally enters the stack of the fuel cell 17. The high pressure compressed air reacts with the hydrogen in the fuel cell 17 to generate electrical energy, water and a portion of the heat. Since only a portion of the oxygen in the compressed air is involved in the reaction, the remaining compressed air is discharged by the fuel cell 17. The discharged air still has a certain pressure, and in order to save energy in this part of the discharged compressed air, a turbo-expander 14 is provided coaxially connected to the motor 13, and then the part of the compressed air is discharged from the fuel cell 17 to the turbo-expander 14, which blows the turbine 3 of the turbo-expander 14 to rotate. Since the turbo expander 14 is coaxially disposed with the motor 13, the turbo expander 14 drives the compressor together with the motor 13. This corresponds to the recovery of a portion of the energy in the compressed air discharged by the fuel cell 17 by means of the turboexpander 14, which reduces the power requirement of the electric machine 13. The electric energy consumed by the motor 13 is derived from the electric energy generated by the fuel cell 17, so that the energy consumption of the air compressor to the fuel cell 17 can be reduced, and the utilization rate of the energy of the fuel cell 17 is further improved. If the fuel cell 17 is installed on the automobile, the consumption of hydrogen by the fuel cell 17 per unit journey of the automobile can be reduced, and the endurance mileage of the automobile can be improved. In the process that the turbo expander 14 receives the compressed air discharged by the fuel cell 17 and is driven, since the compressed air is humidified before entering the fuel cell 17, the air carries much moisture, and the fuel cell 17 itself generates moisture after reaction, and when the moisture enters the turbo expander 14, the moisture is likely to enter the motor housing 6 through the gap between the turbo expander 14 and the motor 13, so that the stator, the rotor and other components inside the motor 13 are rusted. To this problem, the utility model discloses set up sealed gas circuit 15, prevent that the air in the turboexpander 14 from entering into inside motor casing 6.

The sealed gas path 15 is connected between the turbo expander 14 and the motor 13 from the exhaust port of the intercooler 9. Specifically, referring to fig. 2, the rotating shaft of the motor 13 and the rotating shaft 5 of the turbo expander 14 are coaxially arranged, a centering sleeve 4 is sleeved on the rotating shaft 5 of the turbo expander 14, a back plate 2 of the turbo expander 14 is arranged on the centering sleeve 4, the back plate 2 is located between the turbine 3 of the turbo expander 14 and the motor 13, and the bearing seat 1 of the motor 13 is connected between the motor housing 6 and the back plate 2. These components constitute a connection structure between the motor 13 and the turbo expander 14, and the compressed air in the turbo expander 14 easily enters the inside of the motor case 6 through the gap between these components. Therefore, a sealing air passage 15 is provided to avoid this. A channel 7 for air to pass through is sequentially arranged along the motor shell 6, the bearing seat 1 and the back plate 2, the channel 7 is communicated with the sealing air path 15 to form a part of the sealing air path 15, and the part is connected to the intercooler 9. Two groups of piston rings 8 are arranged between the centering sleeve 4 and the back plate 2, and a channel 7 of a sealing air path 15 is arranged between the two groups of piston rings 8. By providing the piston ring 8, the radial clearance between the centering sleeve 4 and the back plate 2 can be reduced, so that the amount of leakage can be reduced. Seal gas of higher pressure is driven in between two sets of piston rings, and seal gas can be revealed towards 8 both sides of piston ring, and this is revealed and can not bring the boundary influence, can stop totally moreover that humid air in the turboexpander 14 gets into in the motor casing 6 from between the housing 4 and backplate 2. If the piston ring 8 is not provided, the flow rate for the seal gas becomes large.

In some embodiments, the compressor may be configured as a two-stage compressor, i.e. comprising a first compressor 11 and a second compressor 12, the first compressor 11 being connected in series with the second compressor 12, wherein the first compressor 11 is a low pressure stage and the second compressor 12 is a high pressure stage, i.e. the outlet pressure of the first compressor 11 is less than the outlet pressure of the second compressor 12, and then the second compressor 12 is connected with the intercooler 9. Air passes through the first compressor 11 and then enters the high-pressure second compressor 12 for secondary compression, the obtained air pressure and flow are higher, and the applicable power range of the fuel cell 17 is larger. The impellers of the first compressor 11 and the second compressor 12 are arranged on the same shaft 5, the shaft 5 being driven by a motor 13. The two-stage compressors may be connected back to back, that is, the back surfaces of the pressing wheels of the first compressor 11 and the second compressor 12 are adjacent, and the air inlets of the two compressors are respectively located at two sides of the whole body formed by combining the first compressor 11 and the second compressor 12. Wherein the first compressor 11 is located at the outside and the second compressor 12 is located at the inside. The first compressor 11 and the second compressor 12 may be centrifugal air compressors, or other compressors may be used according to actual requirements. The choice of a specific compressor does not constitute a limitation of the present invention. It should be understood that a single stage compressor may be used for the compressor.

In some embodiments, a cooling gas path 16 is further provided for cooling the motor 13 and the bearings, and discharging the cooled air from the exhaust port.

In some embodiments, the bearing used in the compressor is a dynamic foil air bearing.

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 compression system with a turboexpander, comprising:

a compressor;

2. An air compression system with a turboexpander according to claim 1, characterized in that said compressor comprises a first compressor and a second compressor in series, the outlet pressure of said first compressor being lower than the outlet pressure of said second compressor.

3. The air compression system with a turboexpander of claim 2, wherein a back face of the pressure wheel of the first compressor is adjacent to a back face of the pressure wheel of the second compressor.

4. The air compression system with a turboexpander of claim 2, wherein the first compressor and the second compressor are both centrifugal compressors.

5. The air compression system with a turbo-expander according to claim 1, wherein a passage for passing a gas is provided in sequence on the housing of the motor, the bearing housing of the motor, and the back plate of the turbo-expander, and the passage is communicated with the sealing gas passage.

6. The air compression system with a turboexpander of claim 5, wherein there are two sets of piston rings between the centering sleeve of the turboexpander and the back plate of the turboexpander.

7. The air compression system with a turboexpander of claim 6, wherein the channel is located at a position intermediate the two sets of piston rings.

8. The air compression system with a turboexpander of claim 1, wherein a gas pressure within the sealed air path is greater than a gas pressure within the turboexpander.

9. The air compression system with a turboexpander of claim 1, further comprising a cooling gas circuit connected from the air outlet of the intercooler to the motor for cooling the motor.

10. The air compression system with a turboexpander of claim 1, further comprising an air filter coupled to an air intake of the compressor such that air enters the compressor after passing through the air filter.