Characteristic Simulation And Control Of Supercritical Carbon Dioxide Cycle Power Generation System

In recent years,due to the maturity of turbomachinery and compact heat exchanger manufacturing technology,the research of S-CO2 cycle has arisen again and has attracted much attention in many developed countries.Supercritical carbon dioxide(S-CO2)power cycle system has lots of advantages,such as low cost,high efficiency,and the energy conversion system is considered to be one of the most promising new energy field.At the same time,the S-CO2 cycle has good applicability,and the pyrogen is flexible,including fossil energy,nuclear energy,solar energy,waste heat and geothermal energy.China is in the early stage in the cycle of S-CO2,in order to study the S-CO2 circulation system more in-depth and the future construction of the test bench,the dynamic characteristics of circulating system is importantIn this paper,a simulation model of recompression S-CO2 Brayton cycle power generation system with shunting is established on the Simulink platform for the dynamic characteristics of the system.Firstly,the influence of the characteristics of the circulatory system on the dynamic operation characteristics is analyzed,and verified by the operation model.Then the S-CO2 Brayton cycle power system dynamic characteristic circulatory system of variable condition,variable load,variable speed process and typical disturbance are got,and the impact is analyzed according to the simulation results.At the same time,in order to ensure the safety of circulatory system to operate stably and efficiently,the system parameter limits are analyzed and emulated,and obtained the lowest limit parameters of the circulating system,and puts forward the preventive measures of dangerous points.In the process of system operation,due to the influence of the external environment,the operating parameters usually deviate from the design parameters,resulting in the decrease of the cycle efficiency and even the exiting of the supercritical state,which has a serious impact on the efficiency and security stability of the circulatory system.Therefore,this paper analyzes the control strategy of the constant flow scheme of the main working quality loop and the constant temperature of the main loop outlet temperature,designs the control system and carries out the simulation.Finally,the simulation control effect is analyzed.Finally,this paper puts forward the application of the S-CO2 Brayton cycle power generation system in the arid area,the circulation system of cold and hot end analysis on the tower of molten salt solar energy as heat source,air as cold source,to replace the original structure.According to the different conditions,the cold and hot end analysis of the circulating system is carried out.The air heat transfer model and the molten salt heat transfer model are designed respectively for the day and night,and the steady state verification is carried out.The feasibility of the system is determined and the suggestions for improvement are put forward.