| Comprehensive performance improvement of medium/large scale marine power system has been a hot research topic all around the world due to the ever increasing public attentions on energy crisis and environmental issues.Chemical recuperated gas turbine?CRGT?,one of the most prospective advanced thermal cycles of gas turbines,can not only improve the overall output power and thermal efficiency significantly,but also reduce the pollutant emissions effectively.Hence,it is essential to carry out scientific and optimized-design researches on the main thermal parameters matching and performance further improvement technology of CRGT cycle marine gas turbine,based on some commercial simple cycle gas turbine devices.Comprehensive performance improvement of medium/large scale marine power system has been a hot research topic all around the world due to the ever increasing public attentions on energy crisis and environmental issues.Chemical recuperated gas turbine?CRGT?,one of the most prospective advanced thermal cycles of gas turbines,can not only improve the overall output power and thermal efficiency significantly,but also reduce the pollutant emissions effectively.Hence,it is essential to carry out scientific and optimized-design researches on the main thermal parameters matching and performance further improvement technology of CRGT cycle marine gas turbine,based on some commercial simple cycle gas turbine devices.In this paper,Matlab/VC hybrid programming and Matlab/Aspen plus coupling simulation methods were adopted to build the thermal-parameter matching and overall performance prediction models on marine CRGT cycle gas turbine.During the code program processes,the artificial neural network method and the minimum Gibbs free energy method were used to deal with the characteristic curves of multistage axial compressors and turbines,and predict the steady liquid fuel-steam reforming process individually.Additionally,the equivalent model and thermal performance assessment criteria of chemical recuperated devices were built by virtual temperature method first time.Then,the code validation,compared thermal cycle performance simulations on chemical recuperated device and CRGT cycle,comprehensive design and off-design thermal parameters matching and optimization,further-level improvement strategies on CRGT gas turbine were carried out.Finally,the qualitative and quantitative coupling relations were obtained between the thermal performances?including overall power output power,thermal efficiency,generated steam mass quality,LHV of the reformed gaseous fuel,the ratio of chemical reaction heat and temperature-rise heat?and parameters?such as the pressure ratio and outlet total temperature of combustor?,and the feasible solutions of CRGT performance enhancement were simulated and proposed.From the study,the following conclusions can be drawn:?1?There are critical temperature and critical pressure ration for the chemical recuperated devices and CRGT cycle gas turbine using liquid fuel respectively,which means that once actual temperature and pressure ratio were bigger than those critical values,the fuel-steam chemical reaction would be an exothermic process;?2?Compared with the simple cycle marine gas turbine under the same certain conditions in the maximum total temperature T3 ranges of 1373K1573K,the CRGT cycle gas turbine can increase the maximum specific output power and related thermal efficiency by relative 39%and 28%significantly;?3?The thermal efficiency of CRGT cycle gas turbine is decreased slightly,by 5%more or less even when the pressure ratio decreases from the optimal value 25.4 to 8.6 under the same output total temperature of combustor at 1573K;?4?In the same component characteristic conditions of gas turbine,the CRGT cycle can improve the overall output power from 24.7MW to 34MW,and increase the thermal efficiency from 38.6%to 51.2%comparing with the simple cycle gas turbine;?5?Variable turbine technology can be adopted to increase CRGT cycle thermal performance furthermore. |
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