Study On Modeling And Design Optimization Of Combined Cycle System In IGCC

Integrated gasification combined cycle (IGCC) is a kind of advanced power generation system that combined clean coal technology and combined cycle system together. It is attracting more attention because of its high efficiency and excellent environmental superiority. Now it has been commercially demonstrated, and the first IGCC demonstration in our country is in building. IGCC consists many technologies and equipments, so it is more difficult to optimize the whole system. Though many scholars have studied it by using different methods, theoretical researches on it are still insufficient.This dissertation is based on the subproject "IGCC Power Plant System Optimization Technology" of the project "IGCC Power Plant Design Integration and Dynamic Characteristics" of the National High Technology Research Program (863 Program). The main content of this dissertation are as follows.The model of combined cycle adapted to IGCC system is studied and set up. The type and components of combined cycle system in IGCC have been discussed and the outcomes are in favor of the modeling and design of combined cycle system in IGCC. Some research work is concentrated on Making the combined cycle sub-model connect with other sub-model more precisely and fit to different conditions.The multivariable synthesis optimization of IGCC system is studied in the condition without limiting of gas turbine model in this paper. Through the analysis of the thermal performance of the IGCC system, we choice the independent variables, and then build the general IGCC model based on the general models of the subsystems, in order to synthetically optimize the system without the limit of the chosen gas turbine. By simulating and analyzing the typical IGCC plant, we reveal the principles of performances of the system, which are different from the principle under limit condition. A new method of unlimited synthesis optimization of IGCC system is presented.The efficiency of the steam turbine will be improved, after the flow path of the steam turbine has been reformed in the use of the advanced aerodynamics technology, but at the same time the heat regenerative system will be off the optimal running state. In order to solve this problem, a nonlinear optimization method was applied tooptimize the heat regenerative system, and the cycle efficiency can be further improved. The method and results have a referenced value on the power plant renovation applied IGCC technology.The research achievements mentioned above will provide bases and method of design and optimization for correlative IGCC system, including power plant renovation applied IGCC technology and the first IGCC demonstration in China.