Another new energy storage technology has achieved a new breakthrough!

According to the official Wechat of China Storage Guoneng, recently, the Institute of Engineering Thermophysics of the Chinese Academy of Sciences has made important progress in the research and development of advanced compressed air energy storage technology. The compressor of the first 100 MW international advanced compressed air energy storage demonstration project in Zhangjiakou, Hebei Province has passed the third party test with CNAS qualification. The test results show that the maximum exhaust pressure reaches 100.333 bar, the range of off design conditions is 18% – 118%, and the maximum efficiency reaches 87.5%, It has reached the international leading level.
Compressed air energy storage has the advantages of large scale, long time, low cost, high efficiency, safety and environmental friendliness, and is one of the most promising large-scale energy storage technologies. The “Fourteenth Five-Year Plan” for the Development and Implementation of New Energy Storage Technology takes the 100-megawatt compressed air energy storage technology as one of the key directions for tackling new energy storage core technology and equipment.
The compressor is one of the most important core components of the compressed air energy storage system. Its main function is to compress the atmospheric pressure air to the high pressure state and store it in the gas storage device during energy storage, completing the process of converting electric energy into air pressure energy and heat energy.
Through independent innovation, the Institute of Engineering Thermophysics of the Chinese Academy of Sciences has solved a series of design and manufacturing problems, broken through key technologies such as overall design and optimization, full three-dimensional flow optimization, complex and compact structure design, efficient variable working condition control, and successfully developed a hundred megawatt level compressed air energy storage system multi-stage wide load compressor with full proprietary intellectual property rights, making the compressor highly efficient, high pressure Wide operating range and other advantages.
Large and long-life new energy storage technology
According to the National Energy Administration, by the end of 2022, the installed capacity of new energy storage projects in China has reached 8.7 million kilowatts, of which the installed capacity of compressed air energy storage projects accounts for 2%, which is 174000 kilowatts.
Compressed air energy storage is a new type of energy storage technology derived from gas turbine technology. Its working principle is to start the compressor and compress the air into the gas storage device at night and other low power consumption periods; In the daytime and other peak periods of power consumption, the compressed air stored in the gas storage device is introduced into the combustion chamber, which is transformed into high-temperature and high-pressure gas after heating and heating, and the gas expands to drive the turbine to generate electricity.
In terms of composition, compressed air energy storage system is generally composed of six parts: compressor, expander, heat exchanger, gas storage device, generator/motor and control system.
In terms of advantages, the first advantage of compressed air energy storage is large power, second only to pumped storage power station, and can be applied to 100MW+large energy storage power station; The second advantage is long service life. The service life of the system can reach 40-50 years and can be charged and discharged for tens of thousands of times; The third advantage is that the energy storage time is long, up to more than 4 hours.
However, there are many shortcomings in compressed air energy storage.
1. The layout is not flexible enough. Large compressed air energy storage systems often need to be located in salt caverns, mines, and rock caverns with reliable structures, and cannot be located according to actual needs.
2. The energy storage efficiency is not high, in the range of 60% – 75%, which is relatively low compared with lithium ion battery and other technologies.
3. It takes a long time to start, usually about 10 minutes.
4. High pollution, the process of heating the air to high temperature and high pressure gas requires the use of fossil fuels such as coal.
Research on compressed air energy storage in the Institute of Engineering Thermophysics, Chinese Academy of Sciences
The Institute of Engineering Thermophysics of the Chinese Academy of Sciences has carried out the research on compressed air energy storage technology for the first time in China since 2004. After 19 years of efforts, based on the successful development of the first 1.5MW and 10MW advanced compressed air energy storage national demonstration projects in the world, it has broken through the key technology of 100MW advanced compressed air energy storage and built the world’s first 100MW advanced compressed air energy storage national demonstration system, It was successfully connected to the grid for power generation on September 30, 2022, setting a new milestone in the industry.
The above related work has been supported by the Chinese Academy of Sciences’ strategic pilot project (Class A), the National Development and Reform Commission’s major project of the National Renewable Energy Demonstration Zone, the National Science Fund for Distinguished Young Scholars and other projects.