Simulation Study On Operating Performance Of A Solar-thermal Power System Integration Into A Coal-fired Power Plant

The application of a solar thermal power system integration into a coal-fired power plant reduces the economic and fuel costs of traditional coal-fired units, meanwhile the integrated systems reduce the investment cost and risk of independent solar power plant.The research of dynamic simulation for solar thermal power system integration into a coal-fired power plant has important guiding significance for the field the development of solar thermal power generation.In this paper, the operation characteristics of the solar thermal power system integration into a coal-fired power plant which is formed by the parabolic solar or tower solar thermal system and the coal-fired unit is respectively studied.The design schemes of parabolic solar thermal power system integration into the coal-fired power plant divide into heating feed water and replacing steam extraction using of solar energy. The design scheme of tower solar thermal power system integration into the coal-fired power plant design directly heat the feed water to the main steam parameters of utility boiler for the use of solar, and is sent to the turbine after mixed with the main steam. According to the structure of parabolic solar system and fluid flow characters, the mathematical model of solar thermal system is established. Based on the simulation platform of STAR-90, the simulation systems of parabolic solar thermal system and tower solar thermal system are built. Meanwhile, connected with some350 MW unit simulation system, the simulation models of parabolic solar thermal system and tower solar thermal system integration into the coal-fired power plant are built.On the basis of simulation model, the system operation is simulated, including the start-up, operation, and stopping. What's more, the operating characteristics of different systems and systems under different working conditions are analyzed and studied. The results indicate that between the two parabolic solar thermal power systems, the economic effect of the replacing steam extraction system is better than that of the heating feed water system under the same heat collection area, and the stability of the solar thermal power system integration into a coal-fired power plant is better when the heating feed water system introduced. It is also found that solar thermal system operation have little influence on the operation impact of traditional coal-fired unit, and the control system of coal-fired units do not need to change a lot to achieve the system normal operation.