Performance Simulation Research Of Chemically Recuperated Gas Turbine Cycle

As more and more countries pay attention to the energy issues and environmental pollution problems,the chemically recuperated gas turbine cycle has become current research focus.The CRGT cycle not only has the advantages of large power output,high flexibility,low vibration noise,long lifetime,but also has the advantages of high thermal efficiency and low NOx emissions.Nowadays,the chemically recuperated gas turbine cycle has become one of the most promising advanced-cycles.Setting up a dynamic simulation of CRGT cycle has important significance in making control strategy of the cycle.In this paper,we use a split shaft gas turbine as prototype machine,build up the mathematical model of chemical recuperator and steam generator,study the performance of the cycle using C ++ programming language based on VC2005 platform.The main contents of the paper are as follows:(1)Establishing a simulation model of steam system with flashing as the core,considering the influence of flow pattern on heat-transfer coefficient and the thermal inertia of the system.The simulation results show that the model can accurately and quickly analyze the system performance and obtain the change rule of the parameters under variable inputs when the system is in the steady state variable condition or dynamic variable condition.(2)Establishing simulation model of simple cycle,considering the volume inertia and rotational inertia of the prototype,and the cooling and mixing process of the turbine,and making cycle calculation with the method of variable specific heat.The paper also analyzes the condition under cyclic steady state variable condition and the acceleration and deceleration characteristics of the prototype under low condition.(3)Establishing a simulation model of the steam injected cycle and CRGT cycle,and analyzing the performance of cyclic variable condition.The results show that both the steam injected cycle and CRGT cycle can greatly improve the power and the efficiency of circulation and significantly reduce the temperature of combustion chamber.When inputting the same parameters,the thermal property of CRGT cycle is higher than that of steam injected cycle.For each steady state condition,there exists an optimal replenishment water flow value making the cycle achieve the optimal performance.(4)Establishing a dynamic simulation model of CRGT cycle to investigate the dynamic response of each performance parameter when cycle fuel injection quantity and the make-up water flow change.The results show that when the fuel injection quantity increases,the oversize delivery rate will lead to saturation of water in saturator so as to reduce the heat recovery degree of recycling;when the make-up water flow increases,there is little change of each performance parameter but fluctuation in dynamic process leading to a disturbance of the output power.