Performance Analysis And Optimization Of Solar-Hybrid Coal-fired Power System

Hybrid solar tower and coal-fired power plant is one of the paths to reduce the technological and financial risks,the solar levelized electricity cost(solar LEC)and the carbon emission,and thus promoting the sustainable development.Researches on thermal and economic performance of a solar tower hybrid coalfired power generation system are presented in this paper,and the following are the main achievements:1)A code for the heliostat fields layout and optimization has been development,in this code,the cone optics method was used as the optical model,and the layout and optimization model was based on the radial staggered method;2)The appropriate ranges of the receiver inlet air velocity and aperture area under different absorbed solar fluxes have been investigated,and the result provide a support for the design and operation of the hybrid system;3)The thermal and economic model of the hybrid system has been developed,and 2 scenarios of flue gas heat utilization has been analyzed,and the result shown that using flue gas preheat the feedwater is the best scenario;4)Influences of the absorbed solar flux of the receiver and the heat exchange area of the flue gas heat exchanger on the thermal performance of the hybrid system have been investigated;and then the annual thermal performance of the hybrid system has been investigated,it is shown that the lowest solar LEC(0.1256 $/k Wh),which is much lower than the LEC(0.1787 $/k Wh)[3] of the solar alone plant,occurs when the flue gas heat exchanger is 6 times the heat exchange area of the economizer;compared with the reference coal-fired plant,the annual gross coal consumption rate and the annual coal consumption of the hybrid system reduces by 56.9 g/k Wh and 5.2x104 t respectively.