Design Strategy of Diagonal Compressors in Compressed Air Energy Storage System

As a kind of large-scale physical energy storage, compressed air energy storage (CAES) plays an important role in the construction of more efficient energy system based on renewable energy in the future. Compared with traditional industrial compressors, the compressor of CAES has higher off-design performance requirements. From the perspective of design, it needs to pay attention not only to the performance of the design point, but also to the performance of all the stable working range. However, from the previous literature, no diagonal compressor was used in CAES which can meet the requirements, that also reflects the design program can be further improved. Therefore, this paper studies the design strategy of high efficient diagonal compressor for large-scale CAES, and gives the complete strategy algorithms used for different program modules. The pressure ratio, isentropic efficiency and stable working range are comprehensively considered. In the design process, the criteria for the key parameters of the diagonal flow angle of the diagonal compressor are given for the first time. The results show that the isentropic efficiency at the design point is 92.7