Simulation Research Of Chemically Recuperated Gas Turbine Based On ASPEN Platform

In order to improve the inherent shortcomings of low efficiency and low emissions of the simple cycle gas turbine,the chemical regenerative cycle,which is used to recover the exhaust heat of the gas turbine to increase the thermal efficiency of gas turbine and lower emission.In this thesis,the simulation model of the Chemical Regenerative cycle Gas Turbine(CRGT),which is based on software of Aspen Plus,is presented which applied to triaxial gas turbinr and the steady-state of off-design performance is researched.The main work content is as follows:(1)The simulation model of the gas turbine is established,and at first the working point of the gas turbine is determined which is satisfied the equilibrium condition(including power balance,speed balance,flow balance,pressure balance);Then the design points are calculated and compared with the design manual,which ensure the accuracy.On this basis,the off-design of steady state which included 0.8 condition,0.7 condition,0.5 condition,0.3 condition is studied and the main performance parameters are calculated.(2)The simulation model of chemical regenerator is established,and the exchangerreaction unitseries is identified which is based on CH4 conversion rate and the H2 geneation rate.On the basis of the above analysis,variable condition performance is analyzed,and study the influence of the parameters,such as,reaction temperature,pressure and water/carbon ratio of the catalytic reforming reaction which provides reference for the selection of the process condition of chemical heat recovery system.The results show that the influence of water/carbon ratio on the CH4 is greater than the pressure change,so the conversion of CH4 can be increased by increasing the temperature,water/carbon ratio and pressure.(3)In this thesis,the superheated stream is generated by flash and the water system is established which have two-stage flash.The off-design of steady state is analyzed and study the influence of the parameters,such as,gas temperature,gas flow rate,water flow rate,flash pressure of the performance of water system.In order to obtain the higher flow of stream,the curve of superheated stream with temperature and water flow rate is established,which can provide reference for water control.(4)On the basis of unchanging the characteristics of the gas turbine,which match the chemical regenerative and the simulation model of CRGT cycle is established.Variable condition performance(including STIG and CRGT)is analyzed.The results show that the power and efficiency of CRGT cycle and STIG cycle are increased and then decreased with the increase of water supply when the fuel rate is constant;the power and efficiency of CRGT cycle and STIG cycle are increased with the increase of fuel rate when the water supply is constant.And the lower operating condition,the worse economic performance,but better than the simple cycle.Compared with the simple cycle,the chemical regenerative cycle efficiency increased by 31.18%,and the STIG cycle is increased by 26.48%.