Abstract
In current study, a low temperature organic Rankine cycle (ORC) based on flat plate solar collectors with storage tank is considered. Due to low cost applications, water at ambient pressure is used in both the tank and collectors. Also, the cooling is done by water in ambient temperature. Energy and exergy analysis is used to evaluate the performance of the system under various conditions to find the main sources of exergy destruction and the potential to improve them. Some parameters including exergetic efficiency, thermal efficiency, exergy destruction rate, fuel depletion ratio and irreversibility ratio are investigated. Exergy efficiency and exergy destruction ratio are calculated for the overall system according to the second law of thermodynamics based on daily efficiency. Exergy analysis of each sub-system leads to the choice of the optimum physical parameters for minimum local exergy destruction ratios. Four different working fluids are considered including R245fa, R134a, pentane and toluene to evaluate the system. Results show that the solar collector, thermal storage tank and the vapor generator are the main sources of exergy destruction respectively. Also a parametric study shows that there is an optimum daily exergy efficiency based on turbine inlet temperature. Under the same load, pentane has the best performance followed by R245fa, toluene and R134a. The corresponding daily exergy efficiencies are 24.08%, 22.53%, 22.09% and 21.76%.
Highlights
IntroductionTop cw Cooling water in the field of low grade heat utilization has been investigated by many researchers for decades [4, 5]
A regenerative organic Rankine cycle coupled with a flat plate solar collector was analyzed energetically and exergetically
Exergy analysis gives a better understanding of the system to find the sources of exergy destruction
Summary
Top cw Cooling water in the field of low grade heat utilization has been investigated by many researchers for decades [4, 5]. Except for the selection of working fluid, some researches have devoted to the sensitive analysis of key parameters and performance optimization of the solar-powered ORC He et al [11] conducted a simulation of a solar-powered organic Rankine cycle with parabolic trough collector using TRNSYS software. The overall efficiency of the solar ORC and its optimization with different collector types and working fluids were explored, and the influences of the regeneration process and cycle arrangement on its performance were examined They used the solar-powered ORC to drive a reverse osmosis desalination to produce fresh water for some water shortage areas based on the previous researches [13, 14]. – Presenting a parametric study to determine the key parameters and their effect on entire system and to compare the working fluids performance under the same load
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
