Research On Thermal Perfprmance Analysis And Matching Optimization Of Double-heat Source Triple Supply In Small Buildings

With the shortage of primary energy and the intensification of environmental pollution,the "low temperature air source heat pump" and "building integrated solar energy collection system" were listed as widely used building materials in policy of"Coal-to-Electricity".Therefore,the combination of them will become the development trend in the future.A double-heat source of solar energy and air source heat pump system with hot water,heating and cooling supply was proposed for small villa buildings.Amount of reference data used for the design of heating and cooling system for small buidings were obtained solar energy and heat pump technology combined.Based on the meteorological parameters of Qingdao,the hourly loads of hot water,heating and cooling for villa building were simulated by using TRNSYS software.According to the simulation results,the solar collector area,pump flow,heat pump capacity and tank volume were designed based on the maximum hourly cooling and heating load.The cycle process of the mode of heating and cooling were analyzed,which laid a theoretical foundation for simulation.Combined with the simulation model of double-heat source triple supply system built in TRNSYS,the supply and return water temperature and system energy consumption simulation curves for the hot water,heating and cooling mode were obtained,respectively.The effect of waste heat recovery in heat pump refrigeration was analyzed.It was concluded that the solar energy collection area which was designed to meet the heating demand in winter,was much higher than the hot waster load in the non-heating period.Therefore,the condensing heat recovered from heat pump refrigeration could not be fully utilized.Besides,the solar energy unit and air energy unit could not be match well.In order to resolve the design and control problem of the system,the orthogonal experimental were adopted.Regarding the Life Cycle Cost as an optimum standard,the collector area,volume of water tank,collector tilt,temperature difference of collector thermal cycly and heat pump cycly of hot water and heating supply mode were optimized.The influence degree of various optimization parameters on the solar energy and the operational energy consumptions of system were obtained as well as the optimum design and control parameters were determined to avoid energy waste and reduce the initial investment of the system.Based on the final optimization results,the thermal performance of the double-heat source triple supply system,the solar electric auxiliary system,the air source heat pump system and with waste heat recovery heat pump system were studied.The double-heat source triple supply system has better performance and lower operating energy consumption than others.The dynamic annual cost values method was used to analyze the economy of the above systems and the results showed that the economic benefit of the triple supply system was more remarkable,and the investment can be recovered within 5 years,which embodied the application value of this system.On the basis of consulting a large number of domestic and foreign bibliography,the thermal performance and economic benefit of the double-heat source triple supply system were investigated.The results shown that solar energy and air energy could be combined to meet the demand of building cooling and heating load,and had obvious advantages of energy saving,which provided foundation for the further research.