Economic Analysis Of A Coal-fired Hybrid Power Generation System Assisted By Biomass And Solar Energy

Traditional coal-fired power plants are facing with the problem of large coal consumption, low energy efficiency and serious environmental pollution in the situation of energy shortage and higher coal price. It is of great significance to adjust energy structure, improve energy efficiency, achieve a low carbon economy and make good environmental benefits for traditional coal-fired power plants. Introducing new energy and renewable energy into traditional coal-fired power plants is an effective way to solve the problems above.The coal-fired hybrid power generation system assisted by biomass and solar energy is a novel hybrid power generation system which can ease the strain on fossil fuel supply, improve the efficiency of generating units, increase the economic benefits of power plants, reduce the environmental pollution and save more energy from the generating processes. As a feasible energy saving measure, the coal-fired hybrid power generation system integrates the environmental advantages of renewable energy and the technical advantages of traditional coal-fired power generating technology.In this thesis, the structure of a coal-fired hybrid power generation system assisted by biomass and solar energy is investigated. By analyzing the operating feature of different kinds of biomass gasifiers and solar collectors, a circulating fluidized bed biomass gasifier and a parabolic trough solar collector are selected for the hybrid system. The hybrid power generation system is determined to integrate in the mode of auxiliary system introduced from the water-side of bleeder heaters based on the technical and economic analysis of three modes of integration.For a general diagram of hybrid power generation thermodynamic system, the general matrix models for thermal economic analysis of the coal-fired hybrid power generation system, which are respectively based on energy structure and variable heat equivalent enthalpy drop, are established with energy balance and variable heat equivalent enthalpy drop. The thermal economy of the coal-fired hybrid power generation system is calculated and investigated with the present general matrix models. The effects of unit capacity, auxiliary system active position and flow partition ratio on the thermal economy of hybrid power generation system are analyzed. The generating cost of hybrid power generation system is discussed with different auxiliary system active positions and flow partition ratios. Without taking renewable energy generating subsidies into account, the influences of coal price, CO2emission reduction cost price, biomass energy generating cost price and solar energy generating cost price on the generating cost of the coal-fired hybrid power generation system assisted by biomass and solar energy are highlighted.