Utilization of solar energy in a coal-fired plant

Abstract

Solar energy, as a kind of renewable energy, can be used to heat water in a coal-fired Rankine cycle, that not only promotes the application and research of solar energy utilization technology but also reduces the consumption of coal, which is negative to environment. Thermal economy must be varied when solar heat is used at different stages of water heat absorption process in different capacity coal-fired units. In this paper, this thermal economy variation was analyzed firstly. The results show that using solar energy to evaporate water in large units is more economical than others. And even though the utilization of solar energy for preheating water is less economical, but its efficiency can be as high as that of a SEGS. Secondl y, a solar/coal hybrid system was proposed in which the mature parabolic trough collectors were used to collect solar heat and then integrated into a native 300MW coal-fired unit. Its thermal performance was evaluated and the value of its annual solar heat electric efficiency was gained, which can attain to 27%. Finally, the chosen of designed solar radiation for such a solar-coal combined electric generation system at different sites was studied.