Selection Working Fluid of an Organic Rankine Cycle for Low-temperature Heat Source

Abstract

This paper simulates an organic Rankine cycle (ORC) system for selection the suitable working fluid in low-temperature process. Six commercial working fluids in Thailand comprised of R-245fa, R-152a, R- 142b, R-134a, R-123, and R-1233zd are considered. Nine main parameters−the mass flow rate, vapor quality, pressure, thermal power of pump, working fluid weight, carbon dioxide emission, net power, ORC efficiency, and carbon dioxide per output power impacts−are used to investigate the suitable working fluid. From the study results, it could be found that R-123 has the best values of a highest net power of 20.16 kWe, a highest ORC efficiency of 8.02%, a lowest thermal power of pump of 0.42 kW, and a lowest pressure difference of 539.21 kPa. R-1233zd shows the lowest values of a carbon dioxide emission of 52 kg CO2 eq/100 y and a carbon dioxide per output power of 2.63 kg CO2 eq/kWe. R-134a reveals a highest mass flow rate of 1.19 kg/s. R-245fa has a highest vapor quality of 114.23%. R-152a shows a lowest working fluid weight of 37 kg. Thus, the suitable working fluid of the low-temperature ORC application is R-123 based on the advantages of ORC efficiency, net power generation, thermal power of pump, and pressure difference