阅读说明：本技术 一种废气能量回收型燃料电池用空压机 (Waste gas energy recovery type air compressor for fuel cell ) 是由 张健健 张林营 马超 刘永芳 李伟 付丽娇 王孝丽 马饶村 朱光前 苗熠芝 于 2020-12-30 设计创作，主要内容包括：一种废气能量回收型燃料电池用空压机,涉及燃料电池用空压机技术领域,包括高压级,高压级通过转子轴同轴转动安装有涡轮机。本发明的涡壳进气法兰连接氢燃料电池发动机排气歧管,将发动机排出的废气能量进行回收,做为动力源驱动转子轴做功,实现了回收发动机废气能量,提高空压机整机效率；将其作为辅助动力源驱动转子轴旋转做功,减少电机消耗,提高电机可靠性；降低整机轴向力,提升轴承承载能力的技术效果。(The utility model provides an air compressor machine for waste gas energy recuperation type fuel cell, relates to air compressor machine technical field for the fuel cell, including the high-pressure stage, the turbine is installed through the coaxial rotation of rotor shaft to the high-pressure stage. The volute air inlet flange is connected with the exhaust manifold of the hydrogen fuel cell engine, the energy of waste gas discharged by the engine is recovered and used as a power source to drive the rotor shaft to do work, the energy of the waste gas of the engine is recovered, and the overall efficiency of the air compressor is improved; the rotor shaft is used as an auxiliary power source to drive the rotor shaft to rotate to do work, so that the consumption of the motor is reduced, and the reliability of the motor is improved; the axial force of the whole machine is reduced, and the bearing carrying capacity is improved.)

1. The utility model provides an air compressor machine for waste gas energy recuperation type fuel cell which characterized in that: the high-pressure turbine comprises a high-pressure stage (1), wherein a turbine (3) is coaxially and rotatably arranged on the high-pressure stage (1) through a rotor shaft (6).

2. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 1, characterized in that: the inlet of the turbine (3) is connected with the exhaust port of the engine.

3. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 1, characterized in that: the turbine (3) comprises a volute (2) fixedly connected to the side of the high-pressure stage (1), and a turbine (3) coaxially and fixedly connected with the rotor shaft (6) is rotatably mounted in the volute (2).

4. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 3, characterized in that: the high-pressure stage (1) comprises a high-pressure stage impeller (4) fixedly connected to the rotor shaft (6), and a back disc of the high-pressure stage impeller (4) is arranged in a sunken mode along the outer lateral center.

5. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 4, characterized in that: and a shaft seal (5) is also arranged at the part of the rotor shaft (6) between the high-pressure stage impeller (4) and the turbine (3).

6. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 5, characterized in that: the shaft seal (5) is a labyrinth seal structure.

7. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 2, characterized in that: an air inlet flange (8) is connected to the volute (2), and the air inlet flange (8) is connected with an exhaust port of the engine.

8. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 7, characterized in that: and an exhaust manifold connected with the air inlet flange (8) is connected to an exhaust port of the engine.

9. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 4, characterized in that: one side of the rotor shaft (6) at the low-pressure stage is connected with a low-pressure stage impeller (7).

10. The air compressor for an exhaust gas energy recovery type fuel cell according to claim 9, characterized in that: the low-pressure-stage impeller (7), the high-pressure-stage impeller (4) and the turbine (3) are all milling type aluminum blades.

Technical Field

The invention relates to the technical field of air compressors for fuel cells, in particular to an air compressor for a waste gas energy recovery type fuel cell.

Background

The air compressor is a kind of atmospheric pressure generating device that turns into gas pressure ability with the electric energy, in order to obtain higher gas pressure boost degree, and the structural style of second grade pressure boost even multistage pressure boost has all been adopted to many occasions. In the two-stage supercharging air compressor, a low-pressure-stage impeller and a high-pressure-stage impeller are both arranged on the same rotor shaft, the rotor shaft is driven by a motor to drive the two-stage impeller to rotate, and air is transmitted to the high-pressure stage after being supercharged by the low-pressure-stage impeller. The motor used by the air compressor requires a high-speed and high-output motor, and has higher requirements on the power consumption and the reliability of the motor.

In the normal application process of the hydrogen fuel cell engine, the dependence of the working principle of the hydrogen fuel cell engine requiring high-pressure air on the air compressor is high, and the parasitic power of the air compressor in the whole fuel cell system can reach 25 percent or even higher at present. In recent two years, with the progress of science and technology, more and more technologies which are beneficial to the reduction of the power consumption of the air compressor are continuously available, for example, the type of the air compressor is changed from a roots type to a centrifugal type; the motor is changed from a low-speed motor to a high-speed direct-drive motor, and the like. This series of advances has resulted in a step-by-step reduction in the parasitic power consumption of air compressors in hydrogen fuel cell engine systems, but there is still room for energy recovery during hydrogen fuel cell applications. For example, the exhaust gas temperature after the fuel cell operation is 80 ℃ to 90 ℃, and the exhaust gas pressure is 0.5Mpa, so that a large amount of recoverable energy is contained in the fuel cell exhaust gas.

The prior art discloses a patent of CN211599032U, which includes an intercooling casing sleeved on a middle body, and a flow guiding channel for communicating a low pressure stage and a high pressure stage is provided between the intercooling casing and the middle body. The utility model solves the problems of diffuser cooling and interstage cooling of two-stage supercharging which are not realized in the traditional technology; the conduits need to be adjusted and arranged due to the influence of working occasions and spaces; the pipes after arrangement adjustment cannot ensure smooth circulation of airflow, and the attenuation is serious; and when the charge pressure is increased by the intercooler, the problems that the space layout is limited and the conduit needs to be rearranged are solved.

The device gradually exposes the defects of the technology along with the use, and mainly shows the following aspects:

first, since the temperature of the high-pressure stage is much higher than that of the low-pressure stage when the air compressor is operating, the boost pressure is reduced, resulting in efficiency degradation.

Second, the low pressure level that the center pin both ends of air compressor machine are connected and the load of high-pressure level, the air compressor machine rotates through its motor drive center pin, when causing motor drive, has too high load, influences the efficiency of motor.

And thirdly, when the air compressor works, the high-pressure stage and the low-pressure stage can generate axial force when the air compressor works normally, the axial force is borne by the motor bearing, the reliability of the bearing is influenced, and the service life is prolonged.

In view of the above, the prior art is obviously inconvenient and disadvantageous in practical use, and needs to be improved.

Disclosure of Invention

Aiming at the defects in the prior art, the invention solves the problems that the high-pressure level temperature of the air compressor in the traditional technology is higher, the supercharging pressure is reduced, and the efficiency is attenuated; the motor drives the central shaft to rotate to drive the high-pressure stage blades and the low-pressure stage blades to rotate, and the efficiency of the motor is influenced due to overhigh load; and the axial force can be generated when the high-pressure stage and the low-pressure machine work normally, and the axial force is borne by the motor bearing, so that the reliability of the bearing is influenced.

In order to solve the above problems, the present invention provides the following technical solutions:

an air compressor for an exhaust gas energy recovery type fuel cell includes a high-pressure stage having a turbine mounted thereon through a rotor shaft to be coaxially rotated.

Preferably, the inlet of the turbine is connected to the exhaust of the engine.

As an optimized scheme, the turbine comprises a volute fixedly connected to the high-pressure stage side, and a turbine coaxially and fixedly connected with the rotor shaft is rotatably mounted in the volute.

As an optimized scheme, the high-pressure stage comprises a high-pressure stage impeller fixedly connected to the rotor shaft, and a back disc of the high-pressure stage impeller is arranged along the outer side to the center in a concave mode.

As an optimized scheme, a shaft seal is further arranged on a part, between the high-pressure stage impeller and the turbine, of the rotor shaft.

As an optimized scheme, the shaft seal is a labyrinth seal structure.

As an optimized scheme, an air inlet flange is connected to the volute and is connected with an exhaust port of the engine.

Preferably, an exhaust manifold connected with the intake flange is connected with an exhaust port of the engine.

As an optimized proposal, one side of the rotor shaft at the low-pressure stage is connected with a low-pressure stage impeller,

preferably, the low-pressure stage impeller, the high-pressure stage impeller and the turbine are all milling aluminum blades.

Compared with the prior art, the invention has the beneficial effects that:

the waste gas energy of the engine is recycled and used as an auxiliary power source to drive the rotor shaft to rotate to do work, so that the consumption of the motor is reduced, and the reliability of the motor is improved; the axial force of the whole machine is reduced, and the bearing carrying capacity is improved;

the turbine is added, so that the recovery of the energy of the exhaust gas of the engine is realized, on one hand, the temperature of the recovered exhaust gas is lower than the temperature of a high-pressure stage, the temperature measurement of the high-pressure stage can be reduced, and the supercharging pressure is improved, so that the efficiency is improved, and on the other hand, a power source can be provided for the motor, and the load of the motor is reduced;

after the turbine is added, the axial force at the turbine end is opposite to the axial force at the high pressure level and the low pressure level, so that part of the axial force generated by the gas compressor can be counteracted, the axial force of the whole machine is reduced, and the reliability and the capability of the bearing are improved;

the turbine shell air inlet flange is connected with an exhaust manifold of the hydrogen fuel cell engine, and the energy of exhaust gas discharged by the engine is recovered to drive the turbine to do work; the power source can be provided for the motor, the motor load is reduced, the power consumption of the whole air compressor is reduced, the efficiency is improved, the stability is improved, and the production cost is reduced; the temperature of the recovered waste gas is 80-90 ℃ and is lower than the temperature of the high-pressure stage (the temperature is 120 ℃ after the high-pressure stage is pressurized), the temperature of the waste gas can be reduced by the high-pressure stage, the high-pressure gas is cooled, the heat load distribution of the air compressor is improved, and the pressurization pressure is increased, so that the efficiency of the air compressor is improved;

drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the external structure of the present invention;

in the figure: 1-high pressure stage, 2-volute, 3-turbine, 4-high pressure stage impeller, 5-shaft seal, 6-rotor shaft, 7-low pressure stage impeller and 8-air inlet flange.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1 and 2, the air compressor for an exhaust gas energy recovery type fuel cell includes a high-pressure stage 1, and a turbine 3 is coaxially rotatably mounted to the high-pressure stage 1 via a rotor shaft 6.

The inlet of the turbine 3 is connected to the exhaust of the engine.

The turbine 3 comprises a volute 2 fixedly connected to the side of the high-pressure stage 1, and a turbine 3 coaxially and fixedly connected with a rotor shaft 6 is rotatably mounted in the volute 2.

The high-pressure stage 1 comprises a high-pressure stage impeller 4 fixedly connected on a rotor shaft 6, a back disc of the high-pressure stage impeller 4 is arranged along the outer side to the center in a concave manner,

the sunken structure reduces the weight of the impeller, and reduces the centrifugal stress of the high-pressure-stage impeller 4 while realizing light weight;

on one hand, the low-speed responsiveness of the high-pressure-stage impeller 4 is improved, and on the other hand, the reliability and the service life of the high-pressure-stage impeller 4 are improved.

The part of the rotor shaft 6 between the high-pressure stage impeller 4 and the turbine 3 is also provided with a shaft seal 5.

The shaft seal 5 is a labyrinth seal structure, and the pressure of a turbine back disc and the pressure of a high-pressure-stage impeller back disc are balanced with each other to play a role in sealing; the lubricating oil does not need lubrication, and is suitable for the operating conditions of high temperature, high pressure and high rotating speed.

The volute 2 is connected with an air inlet flange 8, and the air inlet flange 8 is connected with an exhaust port of an engine.

An exhaust manifold connected with an air inlet flange 8 is connected with an exhaust port of the engine, and the energy of exhaust gas exhausted by the engine is recovered and used as a power source to drive the rotor shaft 6 to do work.

One side of the rotor shaft 6 at the low-pressure stage is connected with a low-pressure stage impeller 7,

the low pressure stage impeller 7, the high pressure stage impeller 4 and the turbine 3 are milled aluminium blades.

The milling impeller has high processing precision and better consistency;

the thickness and the blade shape of the cast impeller are limited by a drawing die, and the milling impeller can be processed into a high-performance blade shape by adopting a point milling processing mode;

in the aspect of materials, compared with cast aluminum, the milled impeller material has high strength and good reliability.

Other structures of the air compressor are well known to those skilled in the art and do not belong to the innovation of the present disclosure, so further description is omitted here.

When the air compressor for the waste gas energy recovery type fuel cell works, high-temperature and high-pressure gas discharged from a fuel cell stack enters the volute 2 through the air inlet flange 8 of the volute 2, and the temperature of the volute 2 is about 70 ℃ due to heat transfer of the waste gas of the fuel cell;

the working temperature of the high-pressure stage 1 output by the air compressor during normal work is 120 ℃, and the volute 2 is in direct contact with the high-pressure stage 1 and has larger temperature difference, so that heat balance can be realized between the volute 2 and the high-pressure stage 1 through heat conduction, the temperature of the high-pressure stage 12 is reduced, and the aim of improving the efficiency of the air compressor of the high-pressure stage 12 is fulfilled.

The exhaust gas discharged from the fuel cell enters the turbine 3 through the volute 2 to push the turbine 3 to rotate, and because the exhaust gas expands to do work in the turbine 3, the pressure at the inlet side of the turbine 3 is higher than the pressure at the outlet side, so the turbine 3 can generate an axial tension towards the outside, and by the same reason, the high-pressure stage 1 and the low-pressure machine can also generate an axial tension opposite to the direction of the turbine 3 during normal operation;

without the energy recovery of the turbine 3, the axial forces generated by the high-pressure stage 1 and the low-pressure stage are carried by the motor bearings. This axial force has a negative effect on the life of the bearing and, due to the presence of the turbine 3, the axial forces in both directions can be partially cancelled out, thereby greatly reducing the load on the bearing. The service life of the bearing is prolonged, and the reliability of the whole machine is improved;

meanwhile, the motor with the compressor and the turbine 3 coaxial can realize the aim of acting the air compressor under the action of smaller output current;

the reduction of the motor current can reduce the loss of the motor and reduce the heating of the stator and the rotor of the motor, thereby being beneficial to the reliability of the motor; finally, the temperature and the flow rate of the waste gas after the work of the expansion machine are reduced, which is more beneficial to the working environment of other parts connected in the rear exhaust pipe.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.