Experimental Study of an Organic Rankine Cycle Unit Using Dichloromethane as Working Fluid

Abstract

The Rankine cycle (ORC) is an ideal and mathematical model which is mainly used to prognosticate the efficiency of steam engines. It’s a thermodynamic cycle of a heat engine that converts heat into mechanical work. In Organic Rankine Cycle, organic substances are used rather than water as a working fluid. Organic working fluids are better than water because of having more turbine efficiency due to higher mass flow rate and low temperature heat source can be used to operate the cycle. In this research an experimental setup was locally fabricated to justify the usability of Dichloromethane as a working fluid of ORC power plant. The turbine of this set up was capable of driving a DC generator and it was able to produce up to 10 volts and .09A current while continuously operating the ORC. This preliminary concept was taken to further analyze the properties of Dichloromethane as a working fluid of ORC power plant at various load conditions. Dichloromethane was tested in a mini closed looped experimental nano power generation unit. Temperatures, pressures, mass flow rates, fuel consumptions, vapor generation rates, condensation rates etc. were measured. The nano unit runs at three different operating pressures of approximately 137. 206 and 275 Kpa. The unit had shown its best performance at the operating pressure of 40 psi using R-30 as a working fluid. Not only that, but for all operating pressure it was experimentally proven that, the overall efficiency of ORC unit is always higher than the overall efficiency of the same unit using water as a working fluid.