Design Of Supercritical CO₂ Brayton Cycle And Radial Compressor

In the face of energy crisis and environmental pollution,the fourth generation of nuclear reactors and supercritical carbon dioxide?SCO₂?Brayton cycle can meet people's requirements for green energy and efficient energy conversion system.SCO₂ Brayton cycle is regarded as the main development direction of energy conversion system in the future by more and more scholars.Because it have a lot of advantages,such as efficient,environmentally friendly,wide range of applications and so on.So it is of great significance to study the SCO₂ Brayton cycle and its compressors for future energy development.SCO₂ Brayton cycle has broad prospects and high commercial value.This paper starts from the SCO₂ Brayton cycle system as the research object.A calculation program for SCO₂ recompression Bareton cycle was developed based on the NIST property database.The effect of cycle parameters on the cycle characteristics was analyzed.The results show that pressure ratio and recompression factor have the optimal values.The outlet pressure of the compressor has the optimal range.The capacity of the heat exchanger and the inlet temperature of the compressor have significant effects on the cycle efficiency.Comparing with the other four layouts,the recompression cycle in this article is more suitable for SCO₂.Then,the design of the main compressor in SCO₂ cycle was studied.The aerodynamic design method for SCO₂ centrifugal compressor was introduced in detail.The design program and performance estimation program were developed.After that,the numerical calculation method of SCO₂ compressor is discussed.The SCO₂ centrifugal compressor numerical calculation and flow field analysis were completed.The results show that the compressor designed in this paper has good aerodynamic performance in all conditions.The SCO₂ centrifugal compressor aerodynamic design method adopted in this paper is reasonable and effective.The one-dimensional design procedure and performance prediction procedure in this paper are reliable,and it can be used for preliminary design and performance prediction for SCO₂ centrifugal compressor.