Operation Strategies And Performance Analysis Of Residential Micro-combined Heat And Power System

Combined heat and power system consumes energy to produce electricity while utilizing waste heat,which has high energy efficiency.Residential micro-combined heat and power（m-CHP）system is installed near the residence while reducing the energy loss in the transmission and distribution process.It is regarded as a system which reduces energy consumption and CO₂emissions because of its high energy efficiency.In order to evaluate the feasibility of using the m-CHP system for residential application in China,this thesis analyzes and evaluates the the economic,energy and environmental performances of m-CHP system which is applied to the residences in Harbin.First of all,the operation schedules of the space heating equipment and the electrical equipment are set,then the electricity and heat load profiles（covering on weekdays and weekends）are calculated by using De ST software.A residential m-CHP system model which is driven by internal combustion engine with a 4.0 k W of rated power has been developed within TRNSYS software.Then,based on whether the heat-to-power ratio of demand side is greater than the heat-to-power ratio of supply side,a hybrid electric–thermal load strategy is developed by combining two basic operation strategies,i.e.,following the electric load（FEL）and following the thermal load（FTL）.The electrical and thermal output characteristics of the m-CHP system under three operating strategies are evaluated.The results show that the proportions of operating hours during the heating period of FTL and FEL are 46.58%and 27.97%,respectively.The hybrid electric–thermal load strategy increases the operating hours during the heating period up to 56.96%..Finally,in order to solve the problem of the mismatch between supply side and demand side,two methods of supplementing energy and processing excess energy are defined,namely,off-grid mode and on-grid which is designed to connect to the district energy network.The performance of the energy system with three different operating strategies under the two scenarios is analized,and compared with the separate production of electricity and heat.The results show that when the m-CHP system is applied to the residential building in Harbin,the carbon emissions of FTL and hybrid electric–thermal load strategy in off-grid mode are lower than that of the separate production of electricity and heat,and the carbon emission reduction rates are 28.50%and 39.35%,respectively.The operating costs and carbon emissions of the three operating strategies of FEL,FTL,and hybrid electric–thermal load strategy in on-grid mode are lower than those of separate production of heat and electricity,with economic savings rates of 8.66%,28.67%,and 27.35%,respectively.The results of this thesis provide a basis for reform of space heating with high energy efficiency and low carbon emissions in northern cities in China.