Integrated Optimization Research On Distributed Cooling Heating And Power System

In recent years, as a new energy supply technologies, distributed cooling heating and power system which is considered an efficient, scientific and rational energy useage,has got more and more comprehensive attention. From the present development and market demand of distributed energy, China's development of distributed energy still has a large gap compared to the developed country due to some vague confusion and obstacles to the development of CCHP system.This paper considers the whole years building load distribution of the hotels and office buildings in TianJin. A mixed-integer nonlinear programming (MINLP) model with minimization the annual total cost as objective was established to optimize the facilities scheme and operational strategy of cogeneration system for different types of building.Firstly, an annual hourly building load of the two types of building was obtained throughout the calculations of the building energy simulation software—Energy Plus. Then according to the whole year cycle of operating conditions, an integrated optimization model of system capacity and operation strategy on the target of minimize the annual net present value (NPV)is established. After that, on the condition of different capacity of the CCHP system, the study of operational strategy in different typical days is carried out as well as the analysis of annual primary energy saving rate (FESR), annual operating cost savings rate (ACSR) and annual net present value (NPV) and CO₂ emission reduction.The result shows that, for the hotel building, the economic and energy efficiency of various configurations does not match at the same time. As the annual operating cost savings rate (ACSR) and annual net present value (NPV) can reach maximum under the conditions of two optimal configurations, its primary energy savings rate (FESR) is less than the base-load scenarios. For the office building, the annual energy saving and economy varies widely, the annual primary energy saving rate (FESR) of all the cogeneration models is negative in spring and autumn season while the annual operating cost savings rate (ACSR) is positive. This paper also found that the referred three evaluation indicators are maximum under the conditions of two optimal configurations in office building. This is mainly due to the consistence of building's thermal and electric load except for the transitional season.In addition, this paper also found that the size of the building and its matching synchronism is also important factors which affect the economic and energy efficiency.