Optimal Operation of a Gas Turbine Cogeneration Plant in Consideration of Equipment Minimum Up and Down Times

Abstract

It has become important for operators to determine operational strategies of energy supply plants appropriately corresponding to energy demands varying with season and time from the viewpoints of economics, energy saving, and reduction in CO2 emission. Especially, cogeneration plants produce heat and power simultaneously, which increases alternatives for operational strategies. This makes it more important for operators to determine operational strategies of cogeneration plants appropriately. In this paper, for the purpose of assisting operators or operating plants automatically, an optimal operational planning method based on the mixed-integer linear programming is developed to determine the operational strategy of equipment so as to minimize the operational cost, in consideration of equipment minimum up and down times for each piece of equipment to be operated with appropriate numbers of startups and shutdowns. In the numerical study, the proposed method is applied to the daily operational planning of a gas turbine cogeneration plant for district energy supply. It is clarified how the constraints for minimum up and down times affect the operational strategy and cost. Through the study, the validity and effectiveness of the proposed method is ascertained.