The supercritical carbon dioxide(sCO_(2))Brayton cycle system has become an emerging and highly promising method of thermal power conversion due to its efficiency advantage,system compactness,and excellent adaptabilit...The supercritical carbon dioxide(sCO_(2))Brayton cycle system has become an emerging and highly promising method of thermal power conversion due to its efficiency advantage,system compactness,and excellent adaptability of the heat sources.For the low carbon sCO_(2)Brayton cycle testbed with cycle output power approaching 3 MW,a relatively detailed dynamic simulation model of the entire system is constructed to explore the dynamic response characteristics of the system with different startup strategies and different buffer tank volumes during the startup process.The simulation results indicate that the smaller the volume of the buffer tank,the more rapid and obvious the parameter fluctuation in the buffer tank during the startup.Assuming the allowable relative deviation limit of density is 5%,then the ratio of the buffer tank volume to the volume of the entire closed loop should not be lower than 36.80%.The strategy of simultaneous temperature and speed increase during turbine bypass start can effectively reduce the fluctuation of compressor inlet parameters and reach the steady-state more quickly.This paper provides the recommended matching table for the opening of the turbine bypass valve(TBV)and the main regulating valve(MGV)to reduce the parameter fluctuation during the bypass switching.The effectiveness of the proposed turbine bypass and bypass switching startup strategy is verified by simulation,which may be used as a reference for test bench's future debugging and operation.展开更多
基金supported by the National Science and Technology Major Project of China(Grant No.2017-Ⅰ-0002-0002)Major National Science And Technology Infrastructure"High-Efficiency and Low-Carbon Gas Turbine Research Facility"(Grant No.2017-000052-73-01-001569)。
文摘The supercritical carbon dioxide(sCO_(2))Brayton cycle system has become an emerging and highly promising method of thermal power conversion due to its efficiency advantage,system compactness,and excellent adaptability of the heat sources.For the low carbon sCO_(2)Brayton cycle testbed with cycle output power approaching 3 MW,a relatively detailed dynamic simulation model of the entire system is constructed to explore the dynamic response characteristics of the system with different startup strategies and different buffer tank volumes during the startup process.The simulation results indicate that the smaller the volume of the buffer tank,the more rapid and obvious the parameter fluctuation in the buffer tank during the startup.Assuming the allowable relative deviation limit of density is 5%,then the ratio of the buffer tank volume to the volume of the entire closed loop should not be lower than 36.80%.The strategy of simultaneous temperature and speed increase during turbine bypass start can effectively reduce the fluctuation of compressor inlet parameters and reach the steady-state more quickly.This paper provides the recommended matching table for the opening of the turbine bypass valve(TBV)and the main regulating valve(MGV)to reduce the parameter fluctuation during the bypass switching.The effectiveness of the proposed turbine bypass and bypass switching startup strategy is verified by simulation,which may be used as a reference for test bench's future debugging and operation.
