Two-stage high-speed centrifugal air compressor with double cooling systems for fuel cell

Abstract

The invention discloses a two-stage high-speed centrifugal air compressor with double cooling systems for a fuel cell, and relates to the technical field of fuel cell air compressors. The structure of the air compressor is more compact, and the performance of the cooling systems is improved. The high-speed centrifugal air compressor comprises a water cooling system and an air cooling system; the water cooling system comprises a cooling water flow channel, a cooling water inlet and a cooling water outlet; the air cooling system comprises a cooling gas inlet, a first-stage side annular flow channel, a first-stage side cooling flow channel, a second-stage side cooling flow channel and a cooling gas outlet, wherein an inlet of the first-stage side annular flow channel communicates with the cooling gas inlet, and an outlet of the first-stage side annular flow channel communicates with the inlet of the first-stage side cooling flow channel and an inlet of the second-stage side cooling flow channel; outlets of the first-stage side cooling flow channel and the second-stage side cooling flow channel communicate with the cooling gas outlet; the first-stage side cooling flow channel is used for cooling a first-stage side radial air bearing, a thrust bearing and a motor body; and the second-stage side cooling flow channel is used for cooling a second-stage side radial air bearing and the motor body.

Description

Technical field [0001] This application relates to the technical field of fuel cell air compressors, and specifically to a two-stage high-speed centrifugal air compressor for fuel cells with dual cooling systems. Background technique [0002] In recent years, with the in-depth implementation of the concept of sustainable development, the continuous transformation and upgrading of the energy structure and the vigorous promotion of new energy vehicles, fuel cells have high energy conversion rates, high power density, complete zero pollution and zero emissions, and are suitable for frequent starts. Occasionally and other advantages, it is highly praised and favored by the global automotive industry in the field of new energy vehicle engine technology, and is considered to be the "ultimate choice" for future new energy vehicle power systems. [0003] High-speed centrifugal air compressors have attracted widespread attention due to their compact structure, fast response, high eff...

AI Technical Summary

Problems solved by technology

In order to increase the air supply pressure and flow rate at the inlet of the fuel cell, most high-speed centrifugal air compressors adopt a two-stage booster structure. Drive to achieve ultra-high-speed operation, thereby providing a higher power density for the fuel cell system, but it will lead to local overheating of the stator and rotor of the high-speed motor and local overheating of the air bearing friction, and the air compressor inner cavity A large amount of heat, which makes it difficult to dissipate heat and cool the high-speed motor

If it cannot be discharged to the external environment in a short period of time, the temperature in the motor cavity will rise sharply, resulting in thermal bending deformation and instability of the high-speed rotor, failure of the coating on the surface of the shaft and air bearing, and affecting the clearance between the shaft and the air bearing Cooperate to reduce the rotation accuracy of the rotating shaft; even cause serious consequences such as permanent magnet demagnetization and partial insulation failure of the stator, which greatly reduces the efficiency of high-speed operation and may cause devastating damage to the structure of the air compressor

[0004] The Chinese patent "Cooling System for Two-Stage Air Suspension Centrifugal Electric Direct-Drive Air Compressor" (publication number: CN209704930 U) discloses a cooling system for two-stage air suspension centrifugal electric direct-drive air compressor. The system includes a water cooling device and an air cooling device. The water cooling device mainly cools the stator and rotor of the motor by setting a spiral water channel in the air compressor housing. The air cooling device introduces part of the compressed gas connected to the throat pipe into the motor inner cavity to cool the air Bearings and motor stators and rotors are cooled, but the disadvantage of this patent is: the primary side bearing and the secondary side bearing are cooled through the same cooling pipeline, the cooling effect is poor, and the cooling air comes from the primary compressed Compared with the ambient gas, the temperature of the connecting pipe has increased to a large extent, which greatly reduces the cooling effect of the air bearing, stator and rotor in the enclosed space, and the higher the pressure ratio, the higher the air temperature rise and the better the cooling effect. Poor, without increasing the flow of cooling water, it is difficult to ensure the normal use of the motor, and even threaten the service life of the air compressor

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