The Fundamental Research Of Ambient Pressure Gas-Turbine Cycle

Based on the thermodynamic theory, to design the new cycle system is the basic study for increasing the output and electric efficiency in energy utilization and transformation fields. The research of the energy utilization orderliness and engineering application of APGC/combined cycle with APGC is the main objective and content of this dissertation.The small size of the conventional micro/small gas turbine results in blade path of small dimensions for the conventional turbine. The small dimensions have a deleterious effect on component efficiency. In the APGC operating under ambient pressure, larger specific volume results in large dimension of blade path and higher component efficiency, and the higher overall thermal efficiency also. The APGC can guarantee very low NOx emission to meet the demand of environmental preservation. In the dissertation, the theoretic performance of APGC is discussed, and the cycle performance characteristics are conducted based on the APGC analytic models established with software Aspen Plus. The expert factor analytic method is presented to determine the optimum pressure ratio of the APGC.The new proposed combined power cycle is constructed with the APGC as the bottom cycle and conventional gas turbine as the topping one. The performance analysis and comparison for various combined cycle are investingated in order to achieve the energy utilization efficiently based on the principle of cascade utilization of energy. In large gas turbine plant with a large amount of exhaust heat, the steam and gas turbine combined power cycle is normally used to recover the gas turbine exhaust to produce power. However, in micro/small gas turbine system with a small amount of exhaust heat, the APGC will be effective in recovering the waste heat to produce power. The dissertation reveals the performance of combined cycle as result of varying topping cycle pressure ratio and bottom cycle expansion pressure. The expert factor analytic method, which is significant in theoretic design and practical application of new proposed cycle, is also presented to provide the design pressure ratio of the combined cycle according to the usage of system.Highly effective energy utilization and new energy production become the focus of energy development with increasing in economy and lacking for energy sources in the world. The practical examples with APGC are investigated in the fields of Biogas power generation system, power recovery system of IRON and STEEL works and the hybrid system with SOFC to show a promising direction for APGC application in the future.