Research On Public Building Energy Consumption Simulation And Energy-Saving Reform Technology

In recent years,with the rapid development of economy and science and technology,building energy consumption in our country is increasing,faced with problems in existing buildings,government has come up with policies that were ralative with energy-saving retrofit.At the same time,lots of researchers have studied the energy-saving reform technology.Therefore,studying building energy saving technology is key to achieving the goal of "energy conservation and emission reduction".Public building energy saving was taken into account,and building energy-saving retrofit technology was in an further discussion and research in this paper.Before the research,investigations on basic situation and energy-use condition of campus building in Shenyang have been carried on,and a typical public building was selected as research object.The results show that exterior wall heat transfer coefficient of typical office building is 0.639W/(m2 · K),and roof heat transfer coefficient is 0.973 W/(m2 · K),and exterior window heat transfer coefficient is 2.6 W/(m2 · K),so the coefficients have a certain gaps compared with thresholds in criterions.In addition to exterior envelopes,cold and heat source in office building exists many problems because of long-running,such as corrosion,leaking,and decreasing operating efficiency.In order to solve problems in office building,exterior wall,exterior window and roof were analyzed based on DeST-C simulation software.The results showed that insulation thickness of exterior wall had obvious effect on building air conditioning load,and annual total heating load decreases with the increase of insulation thickness,and material costs increases with the increase of insulation thickness,while fuel costs for heating in later period decreases with the increase of insulation thickness,so the optimum insulation thickness of exterior wall in all-life cycle is 45mm.The optimum roof insulation thickness increased based on roof foundation in all-life cycle is 20mm during its retrofit.During the exterior window retrofit,if window frame material is plastic steel.and spacer-layer thickness of insulating glass is 12mm,and spacer-layer gas is air,glass color is colorless,and glass is low-e insulating glass(radiancy≤2.5),heat transfer coefficient and air conditioning load reach the minimum,and energy saving effect is the best.Then effect that cold and heat source had on building load was analyzed based on TRNSYS simulation software,and the results showed that ordinary water source heat pump with smaller capacity(LSBLGR-550M)has best operating effect,and power consumption of heat pumps and pumps reach the minimum,and the coefficient of performance is 4.21,which is higher than that of original water source heats pumps(COP=3.12).In addition to the analysis of exterior wall,exterior window and roof,new energy-saving technology in green buildings was used in the retrofit of glass curtain walls,roof windows and central ventilation system of office building.Exposed aluminium alloy frame supported glass curtain walls can be replaced with wood alu-clad frame,or the original glass curtain walls can be converted into fully-implicit glass curtain walls.Static roof windows can he replaced with electrodynamic roof windows,and the natural ventilation can be improved.Fresh air pretreatment was considered in the retrofit of central ventilation system,and utilization of solar system can not only reduce the power consumption of central ventilation system,but also enhance the ventilation of solar chimney,and improve indoor air quality in office building.Finally,according to the retrofit scheme of typical office building proposed in study,air conditioning load and natural room temperature variations before and after retrofit in office building were analysed,and the energy saving effciency was calculated.simulation results showed that the annual total heat load decreased by 12.6%after retrofit,and annual total cold load decreased by 5.04%,and annual total load decreased by 10.57%.In addition,the total hours of typical rooms decreased obviously for the temperature less than 16℃ or more than 35 ℃.In aspects of energy saving efficiency,52477.65kg standard coal was saved by exterior envelop retrofit,and cost saving was 26238.82 yuan.At the same time,102929 KWh was saved by retrofit of cold and heat source,and power consumption decreased by 25.94%compared with original water source heat pump,and annual cost-saving was 51464.52 yuan,and annual total cost-saving was 77703.34 yuan.Thus,this energy-saving reform study not only provided technical reference for retrofit of campus office building,but also lay foundation for promoting college-saving campus construction further.