Research On Optimizing Configuration And Flexible Design Of Combined Cooling,Heating And Power For Office Buildings

With the increasing consumption of energy and more importance paid on green house gas emissions and sustainable development,energy saving and emission reduction have become our common goal.As a distributed energy system,CCHP system has great advantages in energy efficient utilization.In this paper,the CCHP system driven by internal combustion engine is taken as the research object,and office buildings are taken as the energy consumption side.The supply side and demand side are studied separately and comprehensively,which will provide some guidance for the popularization and application of CCHP system.The mathematical model of the CCHP system driven by internal combustion engine and the physical parameters model of each working sub stance are constructed to provide the basis for further optimization of the application and building model of the CCHP system.A new type of cogeneration system based on gas internal combustion engine and direct expansion solar heat pump water heater is proposed and designed for the heating demand in southern China.The solar energy heat pump is driven by gas internal combustion engine.At the same time,the solar energy heal pump generates heat connectes in series with the cylinder liner water waste heat and flue gas waste heat to realize cogeneration of heat and power.DeST software is used to build an office building model and set the corresponding parameters.A new energy consumption forecasting method is proposed by dynamic simulation of the main factors affecting the load of office buildings.The calculation is simple and fast.Firstly,the influence of building energy consumption is studied from three aspects:building floor number,insulation layer thickness and ventilation frequency.Then,the influence of three factors on building load is further analyzed by orthogonal experiment method.Finally,the prediction analysis of building cooling and heating index under three factors change is established by SPSS software.The analysis results show that the influence of the thickness of insulation layer,the number of floors and the number of ventilation on the building cooling and heat index is consistent with that of single factor analysis,and the error between the prediction model and the simulation value is less than±3%.The forecasting model can provide guidance for regional building energy consumption forecasting.At the same time,the optimal insulation thickness of the building can be obtained by optimizing the combined supply system based on the optimal insulation thickness.The influence of different load characteristics in different areas on the capacity of the equipment of the combined power supply system driven by internal combustion engine is studied.At the same time,in order to solve the contradiction between the static design condition and the actual variable load operation condition of the system.a flexible design method of CCHP system is proposed.In order to study the effect of load characteristics on the economy of the combined cooling and heating system,a model of combined cooling and heating system and an economic optimization model are established for an office building in Beijing.The influence weights of heat-power ratio and cold-power ratio on the annual total cost of the system are 48.6%and 51.4%,respectively.A total of 16 sets of equipment capacity configuration schemes were operated under typical conditions of Beijing to obtain optimum design condition,including the heat-to-power ratio of 1.32 and the cooling-to-power ratio of 1.26,the annual variance of the total cost of the system of 12.52.Under the traditional static design conditions(HP=1.20,CP=1.15),the annual variance of the total cost of the system is 17.91.Under the flexible design conditions,the system is more stable than the traditional static design.