貯湯量に関する周期境界条件を考慮した家庭用PEFCコージェネレーションシステムの最適運用計画

Abstract

This paper proposes a new operational planning method for residential PEFC (Polymer Electrolyte Fuel Cell) cogeneration system considering the periodical boundary conditions concerning hot water in storage tank. It can be easily expected that residential PEFC cogeneration system is likely to produce more hot water than needed, because heat efficiency of PEFC is higher than its electrical efficiency. In that case, the surplus hot water would be discarded, and it might deteriorate total operational cost. However, previous researches have not discussed and focused on how to deal with the surplus hot water, and when to discard it. Therefore, we introduce periodical boundary conditions concerning hot water amount in storage tank, and include the cost of disposal hot water as the penalty into our objective function in order to consider them in the operational planning. We simulate the operational planning in the conditions of 3 seasons by using 2 methods, which are proposed method considering periodical boundary constraints and conventional method of operational planning. The study system is configured of PEFC, commercial grid, storage tank, and auxiliary gas boiler. The simulation results show the efficacy of proposed method in many cases. In addition, the bird's-eye view figures composed of optimal solutions reveal some information about the way to decide the appropriate periodical boundary conditions.