抄録
This paper describes influence of operating modes on the primary energy saving of a residential cogeneration system. Recently, some 1[kW]-class cogeneration systems (CGS) have been developed. However, daily electricity and thermal demands in one home, especially thermal demand, change very sharply minute to minute, and the thermal/electric load ratio also fluctuates very widely. There are quantitative changes of demands, in addition, with season even in an identical home. Therefore, the introduction effect of such a CGS will change largely with the demand pattern and the CGS operational pattern, and it is thought that selecting the effective operational pattern responding to the demands of each home is quite necessary for energy saving. This paper proposes a daily start and stop algorithm for a residential CGS using the estimated thermal demand curve of the day which derived from integrating the averaged thermal demands of three days before the day. Simulation results shows that about 20[%] primary energy reduction in winter season can be obtained if choosing the optimal combination of engine output and the start-up time precisely with the estimated thermal demand curve, and that when rather small engine output is selected, early start-up time is preferable for improvement of the energy saving.
