Performance of Organic Rankine Cycle Using Biomass As Source of Fuel

Abstract

A simulation study has been done on Organic Rankine Cycle (ORC) with nine different working fluids in four different types of system configurations. An Organic Rankine Cycle is similar to Rankine cycle with the exception of using organic fluids for its working fluids. It is widely claimed to be more effective than steam Rankine cycle in low heat grade applications. The objective of the study is to study the performance of the system in conjunction with biomass thermal system by selecting the best working fluid and system configurations. The simulation is done using MATLAB and REFPROP 9.0 respectively. The selection of the best configuration is based on the thermal efficiency of the system. It is found that toluene is the best option in simple ORC system. In ORC system added with internal heat exchanger or recuperator, dodecane and propylcyclohexane are the better option compared to other fluids. All the organic fluids show improvements with addition of recuperator. For temperature range of 150oC-300oC, it is found that water is not effective compared to organics fluids. Superheating process shows a slight improvement in a system with recuperator, but no improvement in simple cycle. The highest thermal efficiency is found in Scenario D. The second best is Scenario C, followed by Scenario A and the most ineffective is Scenario B.