Study On Comprehensive Energy Performance Of Shading Systems In Different Climatic Regions

Building energy conservation is an important way to reduce the energy consumption and realize the sustainable development.Windows are the key components for heat transfer of building envelopes,which is one of the main factors influencing indoor thermal environment and building energy conservation.Therefore,Shading systems related to the energy consumption of windows are very essential for buildings energy conservation.This paper mainly focused on the study of thermal performance,daylighting performance,electricity generation performance(photovoltaic shading modules only)and comprehensive energy performance of four traditional shading systems(fixed-awning,roller shade,cellular shade and horizontal-blind)and photovoltaic shading modules(PVSMs).And the structure parameters of traditional shading systems and PVSMs were also optimized.Finally,the optimal design schemes of various shading systems in di fferent climatic regions were obtained,which provides a significant reference for selecting suitable shading systems in different climatic regions.In terms of the simulation,the total energy consumption of four traditional shading systems with different qualities and setting modes in Changsha were compared by establishing a typical resident building model in EnergyPlus.And the most suitable shading system for resident buildings in hot summer and cold winter area was obtained.Then,the net energy consumptions of PVSMs with different azimuths and tilt angles were analyzed by using the PVSMs model established in EnergyPlus and the optimum tilt angles for PVSMs with different azimuths in hot summer and cold winter area were obtained.In addition,the energy performance between traditional shading systems and PVSMs were compared and the results show that compared with the traditional shading systems,PVSMs possess the best energy performance.Further,in order to analyze the energy saving potential of PVSMs i n different climatic regions in China,the PVSMs model mentioned before was also employed to investigate the annual and monthly optimum tilt angles of PVSMs for maximizing the electricity generation or minimizing the net energy consumption.Five cities,viz.Harbin,Beijing,Changsha,Kunming,and Guangzhou,were selected as representative cities for different climatic regions.The results show that,compared with the PVSMs installed with annual optimum tilt angles,PVSMs with monthly optimum tilt angles mounted in the south possess larger energy-saving potential than those mounted in the east and west for all climatic regions.In the end,in order to promote the commercial application of PVSMs,the comprehensive energy performance and economic performance of PVSMs installed on high rise buildings were illustrated and the optimum tilt angles and widths of PVSMs installed in different climatic regions were obtained.Five cities mentioned before were also selected as representative cities for different climatic regions.The results indicate that the optimum tilt angles for PVSMs installed in Harbin,Beijing,Changsha,Kunming and Guangzhou are 55°,50°,40°,40° and 30° respectively.And the optimum widths for PVSMs installed in five climatic cities are all 1.15 6m.Furthermore,the results show that high rise buildings installed PVSMs with reasonable design in five cities all show the excellent comprehensive energy performance and economic performance compared with the roof photovoltaic systems and traditional power supply mode in public buildings.As for the experiment,firstly,the power performance parameters of the polysilicon photovoltaic module were measured,which was the basis of the power simulation of PVSMs in EnergyPlus.Then,the experimental platform of PVSMs was built to measure the electricity generation of PVSMs,and the measured power was compared with the simulated power to verify the accuracy of Equivalent One-Diode model in EnergyPlus.Finally,the analysis of energy performance and the optimization of structure parameters of PVSMs can be conducted by the verified model in EnergyPlus.The conclusions of this study provide a theoretical basis for the design and installation of different shading systems,and also provide the advice for choosing th e suitable shading systems in different climate regions.