Research On Organic Rankine Cycle Of Photovoltaic And Solar-Thermal Combined Power Generation System

Concentrated GaAs cell Has great prospects for development in photovoltaic technology can create abundant available waste heat during the working. Therefore we got the idea of applying the Organic Rankine Cycle (ORC) to generate electricity, and we make a combined power generation system of photovoltaic and solar-thermal. The organic Rankine cycle of combined power generation system is the key in this paper.The extraction of the photovoltaic and solar-thermal combined power generation system is made use of describing the Organic Rankine Cycle and the scroll expander of it.By analyzing and establishing an objective function,we can consider economic and system performance as well as waste heat utilization of the entire system, and built an optimization mathematical model of Organic Rankine Cycle. Then we use this model to analyze the effect of multiple variables of the system and to Compare different working fluids and to design and build a test bench, Preliminary tests. The details are listed as follows:1. confirming the main part of Organic Rankine Cycle in Photovoltaic which is used in solar-thermal combined power generation system and how to select the scroll expander indicate the principles of the selection of the organic working fluid and we have chosen8types of working fluids for the simulation analysis in the next section.2. In this paper, i analyzed the whole process of the Organic Rankine Cycle,and Calculated the required area in the main heat exchanger,i also get the physical parameters of working fluid and Heat-conduction oil. I Selected the target parameter and variable and constraints of mathematical model, and established an objective function of system by linear weighting method.Ⅰ have considered the economic, system performance and waste heat utilization of the entire system. And i also built an optimization mathematical model of Organic Rankine Cycle in the photovoltaic and solar-thermal combined power generation system.3. By preestablished the optimization mathematical model with objective function and Genetic Algorithms optimization of the system,i made a analysis. By analyzing the influences of the evaporating and condensing pressure to the parameters in ORC system,it can be concluded that these two factors are significant to the system performance, and there is a best system comprehensive performance with a best suitable presuse.by analyzing the8types of selected working fluids, we concluded that the comprehensive performance of R600and R245fa are better while the R134a and R122are relatively worse.Analynizing the influences of the flow speed in the evaporator and condenser, we got a conclusion that the system performance declines while the flow speed increases. The impacts between temperature and heat resource of the system indecates that the working fluid must be selected referring to the heat resource temperature. R245fa performs better below100℃while R123acts better above100℃.4. Designing and constructing a Organic Rankine Cycle system experiment platform, we made a incipient experimentation, Then analyzed the result preliminarily,and then summarized the problems which consist in the design and experiment.