Study On Enersy System With Hybrid Using Of Solar And Biomass Energy

The shortage of fossil energy and climate change caused by CO2emission have become an important bottleneck of human society development, and a revolutionary change of the structure of energy sources is imperative. Due to the advantage of cleanness and inexhaustibility, renewable energy will gradually replace traditional fossil energy. As two kinds of important renewable energy, solar energy and biomass energy have got more and more attention from both academia and industry in recent years.Supported by the National Basic Research Program (973Program) and the National Natural Science Fundation of China, this thesis carried out the research on energy system with hybrid using of solar and biomass energy.The efficiency of solar parabolic trough power plant is too low and the capacity of biomass combustion power plant was too small. To overcome their individual drawbacks, a new solar/biomass hybrid power generation system was proposed. The thermal performance of the new hybrid system was simulated, and the exergy change was analyzed. The effect of using solar heat to replace steam extractions from different turbine stage was studied.Aiming at the operation conditions of the new solar/biomass hybrid power generation system with off-design solar radiation, two regulation methods, changing fuel flow rate regulation and changing working fluid flow rate regulation were proposed. When DNI changed from500-900W/m2, the thermal performance of the hybrid system using two regulation methods was studied and compared. Changing fuel flow rate regulation can ensure that the steam turbines run at full load and the net solar-to-electric efficiency keep at a relatively high point, while changing working fluid flow rate regulation can maintain the solar share at a relatively high point.The process of hydrogen production from steam reforming of ethanol was simulated, the effect of operating conditions (including temperature、pressure and steam to ethanol molar ratio) on the product was discussed. A cogeneration system combining cooling、 heating and power was proposed, using micro gas turbine as power equipment and ethanol integrated with solar energy as energy source. The cogeneration system used solar heat to drive the reaction of steam reforming of ethanol to produce hydrogen-rich gas fuel. Energy balance and exergy balance analysis of the new system were taken. The thermal performance of the new system with off-design solar radiation is simulated. The effect of key operational parameters such as turbine initial temperature、pressure ratio and temperature difference of the regenerator on the thermal performance were discussed.