Experimental research on the domestic ORC micro power plant with a commercial biomass boiler

Abstract

The purpose of the work was to experimentally evaluate the operation of the domestic ORC micro power plant that uses a commercial biomass boiler fueled with wood pellets. The boiler, with a maximum thermal power output of 45kWt, uses a heating jacket and thermal oil as a working medium. The prototypical domestic ORC micro power plant was equipped with a multistage radial-flow microturbine that can generate electricity (2.5kWe at a rotational speed of 24,000 rpm). The microturbine is a key component of the turbogenerator, which was manufactured in oilfree technology. The turbogenerator’s high-speed bearings are lubricated with the low-boiling medium’s vapour. The HFE7100 fluid was used as a working medium in the ORC installation. The paper discusses the thermodynamic conditions to be met for effective operation of the boiler and the results of experimental research. The operating characteristics of the ORC installation and the biomass boiler were presented. Problems that occurred while testing the micro-cogeneration power plant with the boiler and their impact on the electric and thermal efficiency of the cycle were discussed.