Study On Solar Organic Rankine Cycle Power Generation System

At present,with the rapid development of people’s living standard and the rapid development of economic society.China has witnessed a sharp increase in energy exploitation and energy consumption,resulting in the current situation of unstable and unsustainable energy.Therefore,developing new sustainable energy and improving energy utilization rate through more energy utilization technologies will be one of the important development directions to change the energy situation.Aiming at the problem of soil heat imbalance caused by the operation of ground source heat pump one season in a year,and the problem of energy waste caused by the direct heat supplement of solar energy across seasons,the organic Rankine cycle power generation system of solar energy is proposed,which can not only compensate for the problem of soil heat imbalance caused by the operation of ground source heat pump system one season in a year,but also can use the temperature difference between the cold and heat sources to generate electricity and improve the utilization rate of solar energy.In this thesis,the thermal process of solar organic Rankine cycle power generation system is simulated by EES software.When the temperature of the heat source is 65～90℃,the evaporation pressure,evaporation temperature,system net power generation,thermoelectric efficiency and system heat absorption are positively related to the temperature change of the heat source.When the heat source temperature is 65～90℃,the RC318 system has the highest efficiency and low evaporation pressure.At the same time,the effects of the changes of evaporation temperature,condensation temperature,heat and cold source flow and other parameters on the net power generation,thermoelectric efficiency and heat absorption of the system are simulated.The results show that the objective functions are positively correlated with the changes of evaporation temperature,cold source flow and heat source flow,and negatively correlated with the changes of condensation temperature,condenser and evaporator narrow point temperature difference.In addition,the influence of parameter changes on the objective functions of the system is simulated.It can be seen that each objective function is positively related to the changes of evaporation temperature,cold source flow and heat source flow,and negatively related to the changes of condensation temperature,condenser and evaporator narrow point temperature difference.On the basis of simulation,a 3 k W solar organic Rankine cycle generator set is designed and built.First,the system equipment is selected through design calculation.According to the analysis of experimental data,the heat absorbed by the system reached38k W,and the heat released by the system reached 30k W.At the same time,the heat transfer coefficient of the heat exchanger is 2231.8 W/（m²?℃）,and the heat exchange of buried pipes is always stable.Therefore,it is feasible to use the solar organic Rankine cycle system to solve the problem of soil heat imbalance.Taking a project as the research object,analyzes the organic Rankine cycle system by the full life cycle assessment method,and evaluates the impact of environmental categories by Simapro software and Re Cipe Midpoint method.First of all,this project is a waste heat recovery project,without primary energy consumption,and the operation of the organic Rankine cycle system is completely dependent on its own power.Therefore,only in the system construction and transportation stages,there is a small impact on the environment.Second,the assessment shows that the total life cycle CO₂ emission of the project is 71 t,and the full life cycle organic Rankine cycle system save 11644 t CO₂emissions for the plant,achieving the goal of carbon emission reduction.