Coupling Study Of Supercritical Carbon Dioxide Brayton Cycle Power Generation And Energy Storage System

China's economic operation continues to be stable and the trend is good,national electricity demand is growing rapidly,However,the power consumption is non-periodic,and there are peaks and valleys,which makes the low power consumption in many time periods,resulting in huge energy waste.In this paper,a simulation model is established for the compressed carbon dioxide energy storage system and the supercritical carbon dioxide Brayton combined cycle.For the thermal efficiency comparison discussion on the supercritical recompressed carbon dioxide brayton cycle system and the preloading precooling system.Explore whether it can effectively improve energy efficiency,based on the initial pressure,initial temperature,splitting coefficient,preload pressure and preheating temperature as variables,the cyclic efficiency changes of recompression and preloading precooling systems were studied,and compare the damage of the two systems and the optimal cycle efficiency of the system.The thermal efficiency and energy storage density of the energy storage part system are analyzed,the thermodynamic analysis of the energy release part of the compressed carbon dioxide energy storage system is carried out.The results show that the initial temperature initial pressure and the splitting coefficient have a great influence on the thermal efficiency.The optimal shunting coefficient must exist in both systems to achieve optimal efficiency of the system;under certain conditions,the higher the initial temperature,the higher the cycle efficiency,and the higher the initial pressure,the higher the cycle efficiency and then decrease.The initial temperature of the circulation system is 720 ° C,and the initial pressure is below 20 MPa.The pre-pressure and pre-cooling system has higher cycle efficiency than the re-compression system and the cycle efficiency is over 50%.It is found that the energy storage pressure and the energy release pressure have a great influence on the energy storage efficiency and energy density.The heating temperature,pressure ratio change and release energy pressure change will cause the system heat exchange,system output power and system efficiency.The use of supercritical carbon dioxide brayton cycle power generation system has higher power generation efficiency and better thermal economy.The excess energy of the supercritical carbon dioxide Brayton cycle system is used to drive the compressed carbon dioxide energy storage system for energy storage during the low peak period of power consumption,and the two systems simultaneously generate electricity during the peak power period,thereby reducing energy waste.In short,the use of combined cycle systems can reduce energy waste and improve energy efficiency.