Study on small-scale co-generation system for domestic house considering partial load and load fluctuation

Abstract

A prototype co-generation system for domestic houses is constructed, and cost reduction and energy saving of the system are studied. The system is constructed to use electricity either from utility or generated by the co-generation system. One of those two electric sources is selected by changeover switch according to cost-minimum control. In addition, by converting optimum amount of generated electricity to heat using an electric heater, the working point of the engine of the co-generation system is tried to be shifted to the highest efficiency condition. New control algorithm is developed to select optimum conversion rate of electricity to heat by electric heater when time-dependent demand of electricity and heat is given. Effects of load fluctuation on the operating cost is also studied. Annual energy cost is calculated to be decreased by 30 per-cent by the system.