Aerodynamic Design And Analysis Of A Multistage Centrifugal Compressor In CAES

Electric Energy Storage (EES) refers to a process of converting electrical energy from a power network into a form that can be stored for converting back to electrical energy when needed. These technologies can effectively adjust China’s energy structure, promote the use of renewable energy in a large scale and increase the traditional power system efficiency, security and economy. Compressed Air Energy Storage (CAES) has great prospects for development with large storage capacity, high efficiency and environmental friendly among EES. Currently, the usual compressors are piston, axial and centrifugal. Centrifugal compressor is suitable for the energy storage part of CAES to satisfy the requirements (high efficiency, large flow, high pressure ratio and wide load) of the system.Design method of multistage centrifugal compressor in CAES is studied in this dissertation and an aerodynamic design of a multistage centrifugal compressor is made with the usage of impeller design software and numerical simulation technology. The research contains two parts:overall design and aerodynamic design of each section. And a design scheme of centrifugal compressor with high efficiency and wide load is obtained. The main research contents are as follows:1. Design method of multistage centrifugal compressor in CAES is built. Based on these, an overall design of the compression system is made, including the structural arrangements and allocation of pressure ratio. Then we select the parameters of each section, such as rotational speed and diameter of axle, and analyze the impact performance and design parameters;2. On the basis of the overall design, impeller and diffuser of each section are designed and optimized. Then we investigate the internal flow field and flow characteristics of the impeller and diffuser at the design point condition and obtain the the performance of the multistage centrifugal system. On the premise of satifying the design target, we design several diffusers for the first section, In the end, the influences of different diffuser types on the performance of centrifugal compressor are studied with the aerodynamic performance compared.