Operation Optimization Of Solar Aided Coal-Fired Power Plant

Solar Aided Coal-fired Power Generation system is a coupled system which utilizes various types of solar thermal systems for coupling traditional coal-fired power plants.For current situation, it is undoubtedly an efficient and reasonable mode for utilizing solar thermal energy and reducing coal consumption of coal-fired power plants that aiding coal-fired power plant by parabolic trough solar thermal system. For researching the operation performance and the optimization strategies, the performance analysis model of a660MW solar aided coal-fired powergeneration system under variable operating conditions has been explored. The specific research contents have been showed as follows:After collectingnumerousparameters of660MW coal-fired power plants and solar-only parabolic trough power plants, a performance analysis model a660MW solar aided coal-fired power generation system under5different operating conditions (100%,85%,75%,50%and40%) has been built by applying a series of thermodynamic principles and astronomy theories. For investigating the operation performance of this coupled system, an evaluation method of solar energy contribution was introduced into this model.The thermal performance of the coupled system in four typical days (March14th, June25th, September23rdand December21st) has been simulated. According to the annual solar irradiation data of the region which has been selected, the design value of the system has also been confirmed. The design values of effective direct normal insolation and power plant load are773W/m2and495MW respectively.Basing on these values, the operating characteristics in a typical year have been explored.After analyzing the simulation result, it can be found that the contribution of solar energy does not increase along with the value of effective DNI.It is mainly because of the sustainable growth of solar partexergetic loss when the heat collected from solar field exceeds the optimal value. Basing on this, an optimal operation scheme,which is focusing on the regulation of HTF flow rate, has been presented. A standard noon of a typical day has been chosen as reference, and the effective DNI of this moment has been set from1W/m2to1150W/m2. After a series of simulation, the results demonstrate that the optimization scheme is reasonable and feasible.Basing on the costs of construction, equipment and maintenance of a660MW coal-fired power plant and a solar-only parabolic trough plant, a power generation revenue function of the coupled system has been built. By applying this function to calculate, the economic efficiency of the optimal system has been observed.