Methodological Study on Holonic District Energy Management System

点击翻译按钮获取中文摘要

In this study, many optimal planning methods have been studied for energy supply systems by considering. holonic characteristics. For example, an optimal planning method of system structure is proposed to determine kinds, numbers and capacities of equipment for an energy supply system installed in commercial and public buildings from economic viewpoint. In this method, they are determined together with maximum contract demands of utilities such as electricity and natural gas so as to minimize the annual total cost in consideration of system's annual operational strategies corresponding to. seasonal and hourly energy demand requirements. A numerical study is carried out for an office building. Through the study, the following are clarified : (a) the optimal system structure for the-office building ; (b) the economic effects of the optimal system compared to other typical energy supply systems ; (c) the influence on the optimal system structure of the future efficiency improvement and in … More itial capital cost reduction of equipment. Next, based on the optimization approach, some numerical studies are carried out to plan energy supply systems for hospital. First, energy demands are estimated hourly, daily and seasonally through one year for the hospital. Second, miscellaneous kinds of equipment are listed up such as refrigerators, heat pumps, gas engine cogeneration unit, steam boiler, thermal storage tank, etc., and 25 structures if alternative energy supply systems are composed by combining these kinds f equipment. By the mathematical optimization method, optimal capacities of equipment are determined for the following objective function by taking systems operational strategy into account ; i.e., total cost formulated based on the annual total cost method. Sensitivity analysis is also carried out by changing parametric values related to initial capital cost arid upgrading performance of each equipment in addition to energy charges, and as the. obtained result the optimal energy supply system for the hospital is proposed from comprehensive viewpoints. Finally, an optimization method has been proposed for the renewal planning of energy supply systems installed into buildings. Assuming the raise of future equipment's energy efficiency, the renewal year us determined optimally together with the structure of renewal system. In the mathematical optimization formulation, the annual total cost of the system is minimized in consideration of system's operational strategy corresponding to seasonal and hourly energy demands requirement. Through the numerical study for an office building, it is shown that 2-3% reduction of annual total cost should be achieved if the renewal planning could be optimized based on the proposed method. The influence of the following items on the renewal solution is also clarified ; i.e., available types of equipment to be installed newly, upgrading rates of performance, and so on. For example, it is recognized that the optimal renewal year becomes later if the future upgrading rate of equipment's performance is assumed to be high enough. Less