Study On Key Technology Of Thermodynamic Performance Of Liquid Compressed Air Energy Storage System

With the resources and environmental issues have become increasingly prominent, energy storage technology research and development of more and more countries in the energy, transportation, defense and other departments of the attention. Large-scale energy storage technology will have a profound impact and important role applied to modern energy production and usefulness. This paper relies on. science and technology projects in Yunnan Power Grid Corporation, studying of Liquid compressed air energy storage system, expand research respectively compression and liquefaction process throttling experimental study released from the mechanism and thermodynamic modeling of the energy storage system, the storage system dynamic simulation and control algorithm, energy storage systems, etc.Through theoretical and experimental studies to explore the influence of thermodynamic parameters on the storage/release ability,it can explain and promote mutually restrictive relationship between the various factors, provide a favorable reference for future large-scale development and application of Compressed air energy storage technology.Based on the theory of in-depth study of Liquid and compressed air energy storage system during the release mechanism and thermodynamic properties,this paper using Aspen Plus process simulation software on the system and air compress, throttle liquefied waste heat reusing, expansion work of four sub-units thermodynamic modeling. It is concluded that the air compressor and expander should be level 4 ratio to decorate, low temperature before throttling, high pressure before throttling can improve air liquefaction rate.Utilization of Matlab/Simulink complete systems and sub-unit of thermodynamic dynamic simulation and control algorithm, proposed fitting key parameters before and after the liquefaction process to establish the mathematical model of the liquefaction process method, because the physical process is complex, difficult to modeling and simulation problems, it solved Compressed air energy storage system and the liquid phase transition, in order to grasp the liquid air energy storage system compression/release process critical control technology.In this paper, liquid air energy storage system for the study of the system compression/release process air restrictor liquefaction process carried out relevant experimental study, experiment set up the throttle liquefaction experimental device platform, the main components include:the main heat exchanger,throttle,cryogenic liquid air storage tank,reefer,liquid nitrogen tank,compressed air source, etc. The use of liquid nitrogen as cold source system to explore the effects of air cooling, the throttling process of liquefaction, analysis of pressure, temperature and other parameters of the air liquefaction, the key parameters in order to identify the influence of air liquefaction conditions, impact analysis of system parameters on energy storage, energy release capability, calculate the partial loss of the experimental device, system efficiency analysis to explore factors influencing the efficiency of compressed air energy storage system for liquid correlation and validate the result of the system modeling and simulation. Research shows that before throttling temperature is lower, the higher the pressure, throttle liquefied rate is higher, after experiment system should try to recycle heat transfer medium heat, adding external heat source was taken away is the effective means to improve the system efficiency.