Implementaion of A Small Scale Organic Rankince Cycle Test Bed System Using Steam As Heat Source

Organic Rankine cycle based power systems are well known for waste heat recovery application due to their adaptability to follow heat source variations. Industrial exhaust steam has an appreciable potential for the installation of waste heat recovery units. Korea Institute of Energy Research has developed waste heat recovery units which can generate power in the range of hundreds of kilowatts. In order to, rigorously test new cycle configurations and control strategies with least cost for heat source, a small-scale organic Rankine cycle test bed was implemented which a has steam condensing heat exchanger for using steam as a heat source in similar configurations as of larger units. The test bed was equipped with data logging and standalone control system and was configured for the electrical output around 1kW using R245fa as a working fluid. The system is composed of plate type heat exchangers, scroll type expansion machine, screw type working fluid pump and control valves with actuators. This work will present the difficulties, solutions and operational results in terms of design, equipment selection, fabrication and operational experience of system for small-scale power generation with efficiency over 5.2 % for a temperature difference of 120oC. Complexities involved in superheat control of working fluid for the system powered by steam will also be discussed.