Energy harvesting using solar ORC system and Archimedes Screw Turbine (AST) combination with different refrigerant working fluids

Abstract

In this research, an energy harvesting system was developed for power generation using a combination of an Archimedes Screw Turbine (AST) and a solar Organic Rankine Cycle (ORC) system. An AST was numerically used and optimized for producing mechanical power as an energy harvesting technique. Different structural parameters including the screw inclination angle, number of flights and the screw length were considered. A parabolic trough concentrator was numerically modeled as a heat source of the ORC system. Two different types of absorber were considered using a smooth and corrugated tube. Different ORC working fluids were investigated in the solar ORC system including R134a, R245ca, R245fa, R152a, R113, R11, and R114b. The results of numerical modeling were validated with experimental results and good agreement was found. The results revealed that R113 at the saturated condition at turbine inlet gave the highest ORC net power, ORC efficiency, and total efficiency compared to the other investigated working fluids. The solar PTC system with the corrugated tube showed the higher ORC net power, and overall efficiency compared to the smooth tube as the PTC receiver. The highest efficiency resulted in the screw length of 1.5 m was 58.24% with inclination angle of 25° and flight number of 1. Finally, the optimized characteristics of power generation system including a solar ORC system and a screw turbine (hybrid system) were presented to harvest energy. Application of the presented hybrid system is an acceptable way for increasing and optimizing the ORC power generation.