Experimental transient analysis of micro-ORC system for low-grade heat recovery

This paper presents the experimental analysis conducted on a micro-ORC system, characterized by power output in the kW-scale and employing a radial piston expander. The system operates with heat source temperature below 90 °C and uses R134a as working fluid. An experimental campaign has been performed with the specific purpose of evaluating the response of the micro-ORC system to transient conditions. The response time and settling time are calculated and compared among the key output variables, for different cases of increasing and decreasing variations of the hot water temperature, feedpump speed and external electric load. The behavior of the system during a start-up operation is also analyzed. As expected, the system key variables are more sensitive (i.e. show lower response time) to the variation of the pump speed and of the electric load, than to the change of the hot water temperature. The results of this analysis can provide the basis for the development of efficient control strategies to be implemented on the test bench.     «

This paper presents the experimental analysis conducted on a micro-ORC system, characterized by power output in the kW-scale and employing a radial piston expander. The system operates with heat source temperature below 90 °C and uses R134a as working fluid. An experimental campaign has been performed with the specific purpose of evaluating the response of the micro-ORC system to transient conditions. The response time and settling time are calculated and compared among the key output variables,...     »