Research On Energy-saving Technique Application Of A High-rise Office Building In Changsha City

The energy consumption in public buildings accounted for about 33% of China’s total building energy consumption in 2015,particularly the energy consumption in high-rise office buildings accounted for about 30% of the energy consumption in public buildings,necessitating the reduction of energy consumption in high-rise office buildings as an effective way to reduce China’s urban building energy consumption.With a newly-built high-rise office building in Changsha City as the object of study,this paper has analyzed the influence of various building energy saving technologies on the energy consumption in this building,and has developed an optimal building energy saving technology portfolio suitable for this building.A physical model has been built for this high rise office building in accordance with its basic information in order to calculate the energy consumption in the real building and reference building.The reference building is a kind of common public architecture built in the 1980 s.The real building was compared with the reference in terms of energy consumption,suggesting that the energy saving rate of energy consumption,suggesting that the energy saving rate of this building was 60.53%.On that basis,this paper has classified building energy consumption as energy consumption in lighting system,energy consumption in enclosure structure and energy consumption in air-conditioning system,and has analyzed the influence of existing energy saving technologies on the above three forms of energy consumption under different design parameters.An energy saving technology portfolio contributing to the reduction of energy consumption in this building was finalized.It consists of: low lighting power density and optimized lighting control technology for the lighting system,external wall insulation technology,roof insulation technology and energy-saving heat-insulating external window for the enclosure structure,high-COP direct-fired unit for the air-conditioning system,variable-frequency chilled water system,high-efficiency pump,double-speed cooling tower fan and fresh air heat recovery system.Also,this paper has made an overall energy consumption analysis of this high-rise office building through uniform design experimentation and multiple regression analysis by designating 8 energy saving technologies greatly influencing building energy consumption including pump efficiency,external window shading coefficient,variable-frequency water system,lighting power density,lighting control mode,direct-fired unit COP,external window heat transfer coefficient and external wall insulation as experimental factors,and studied the influence of various energy saving technologies on building energy consumption,identifying the influence in the order of significance: lighting power density > lighting control mode > water pump type > external window shading coefficient > pump efficiency > direct-fired unit COP(No significant influence:exterior insulation layer thickness and external window heat transfer coefficient).The influence of various energy saving technologies on HVAC energy consumption,identifying the influence in the order of significance: water pump type > external window shading coefficient > pump efficiency > direct-fired unit COP > lighting power density > external window heat transfer coefficient > exterior insulation layer thickness(No significant influence:lighting control mode).Based on the above,this paper finalized an optimal building energy saving technology portfolio suitable for this building.The results showed thatthe building energy saving rate reached 68.5%,13.78% higher than the actual building energy consumption.