The Fundamental Research Of High-efficiency And Low-pollution Gas-Turbine Cycle

Based on the present situation of energy development, to design the high-efficiency and low-pollution gas-turbine cycle system is the basic study for the response to advocating energy- saving and reducing exhaust. The research of the performance of the low-efficiency gas-turbine and comparative analysis of combined cycle is the main objective and content of this dissertation.The NO_x emission of conventional combustion is quite high, and also the CO₂, for carbonaceous fuel can not be replaced under current technique. While for APGC, the emission of NO_x and CO₂ is reduced, since part of the emission flows into combustion chamber and cools down the gas, which satisfies the requirement of environment protection. In this paper, part of flue gas recirculation was sent into combustion chamber to form APGC regenerative cycle. And the analysis model was established by software Aspen plus. In the research, cycle performance and quantity of recirculation, the change rule of pressure ratio, and the effect of the fuel gas recirculation to the decrease of CO₂ emission were further studied. Moreover, the effect of quantity recirculation to regenerator effectiveness was emphatically analyzed as a key problem. Therefore, the optimum performance parameters were obtained.The model of gas-steam combined cycle and recuperated combined cycle were established in Aspen plus, and the whole performance of the system was analyzed based on first law of thermodynamics and the second law of thermodynamics. The results indicated that, although the gas-steam combined cycle was superior, it was not suitable for micro gas turbine because of the cost increase based on more bottom Rankine cycle.The new combined cycle is constructed with the recirculation and recuperated APGC combined cycle and the analysis model is established by software Aspen plus. The cycle performance characteristics are conducted based on the quantity of recirculation and the bottom expansion pressure. The expert factor analytic method is presented to determine the optimum bottom expansion pressure of the combined cycle.