Experimental study on power generation plant of a 1 kW small-scale Organic Rankine Cycle system using R290

Abstract

This work presents an experimental investigation of a small-scale cryogenic Organic Rankine Cycle (ORC) power generation plant for cold energy utilization using scroll expander and R290. The fresh water and liquid nitrogen were used as heat source and heat sink, respectively. Furthermore, expander gross output power and isentropic efficiency, system thermal efficiency, and cold energy utilization efficiency were calculated as a principle to evaluate the overall system performance. The experimental results demonstrate that increasing pressure drop and heat source temperature will benefit the system performance in some extent, and the pressure drop exhibits a relative sensitivity to heat source temperature about the system performance. Moreover, the expander gross output power will get the peak value while the heat source and heat sink in the best matching. When the mass flow rate of liquid nitrogen at 120 kg/h, optimum pressure drop is 1.02 Mpa, and the corresponding expander gross output power, thermal efficiency, and cold energy utilization efficiency were 638.2W, 0.0586, and 0.0976, respectively. The optimum heat source temperature is 50℃ under liquid nitrogen mass flow rate of 120 kg/h, and the corresponding expander gross output power, thermal efficiency, and cold energy utilization efficiency were 674.2 W, 0.0594, and 0.099, respectively.