Research On Solar Energy Aided Coal-fired Power Generation System

Faced with the severe situation of environmental pollution, fossil fuel and power supply shortage, combined with rich solar resources of our country, solar energy aided coal-fired power generation was proposed. Being a new composite power system, solar energy aided coal-fired power generation can reduce the pollution of coal-fired power generation and improve the performance of solar thermal power generation, which not only has the advantages of both solar thermal and coal-fired power generation, but also avoids the disadvantages of each power generation. Solar energy aided coal-fired power generation is a new way to build sustainable development power system.Because of the limitations of solar and coal-fired power generation integration system based on design conditions, solar energy aided coal-fired power generation based on practical operation conditions was proposed. Being different with circulation medium of solar collector introducing from coal-fired power generation's circulation feedwater, proposing that introduce the bleeding of feed heater into solar collector and then entering into the corresponding feed heater after converting into steam to heat feedwater, and replacing the corresponding extraction steam. Solar energy respectively integrate with bleeding system with THA,75%THA,50%THA,40%THA,30%THA to be reference and model variable condition iterative calculation method. Thermal performance, collector thermal efficiency and collector field area were analyzed.Coal Saving Rate (CSR) was defined to analyze different modes of solar replacing extraction steam on different reference conditions. The results showed that trend of CSR of different integration modes on different reference conditions is not fully the same, which illustrates the limitations of integration modes based on reference conditions.Auxiliary steam is from extraction steam of auxiliary steam condition, which reduces the thermal performance of unit. Solar replacing the source of auxiliary steam system was proposed and analyzed.Based on auxiliary steam condition of a600MW supercritical unit, analyze modes of solar replacing source of auxiliary steam and extraction steam. The results showed that all the modes'thermal performance is better than coal-fired unit with CSR being index. The most CSR is15.34g/(kW-h), which is solar replacing the2nd extraction steam.