Thermal efficiency analysis of Organic Rankine Cycle (ORC) System from low-grade heat resources using various working fluids based on simulation

Abstract

Thermal Efficiency of Organic Rankin Cycle (ORC) Power Plant System from low-grade heat resources using various working fluids has been analyzed based on the simulation. Four working fluids, namely R-134a, R-32, R-407A, and R-422C were selected on the simulated ORC system to determine its thermal efficiency in some temperature set up of evaporator and condenser. The working fluids are simulated with mass flow rate of 0.15 kg/s at evaporator exit temperature of 75°C, 80°C, and 85°C and at condenser exit temperature of 20°C to 50°C at each 5°C temperature difference. Fluid properties in these conditions are analyzed with REFPROP software then become data input for Cycle Tempo simulation. The thermal efficiency values of each temperature and refrigerant variation are then analyzed to obtain optimum value and variation for the simulated ORC system. The efficiency was obtained at the evaporator exit temperature of 75°C and condenser exit temperature of 45°C. ORC simulation revealed that the optimum and realistic working fluid was R-32 with thermal efficiency of 7.03 %.

Evaluation of Three Working Fluid on an Organic Rankine Cycle of a Waste Heat Recovery Electric Generator

“…From the specification data, it is known that the ORC engine that uses R-245fa has the greatest efficiency when the evaporation temperature is 144 °C with a pressure of 24.5 bar. Then for R-134a, it was obtained from a literature study where in a study it was said that at the evaporation temperature and pressure of 85 °C and 17 had an efficiency of 6.19% [26]. The maximum value of heat-recovery efficiency can be obtained by adjusting the evaporation temperature and condensing temperature.…”

The Influence of Condenser Temperature on the Energy and Exergy Efficiencies of the ORC

“…In theory, it's easier to figure out how much energy the pump used than how much energy it made (the energy produced by the expander). The back work ratio (BWR) compares how much energy the pump needs to how much energy it makes [16]. This helps figure out how much energy the pump uses in the system.…”