Research Of The Nearly Zero Energy Office Building In Guangzhou

Facing with the situation that the conventional fossil energy is currently limited,the energy consumption is in a rapid growth,and the increasing environmental problems caused by the consumption of large amounts of fossil energy are worsening,various countries have proposed higher requirements for building energy conservation,and Nearly-Zero-Energy Buildings have emerged.China has also started to compile Technical standard for Nearly-Zero-Energy buildings.In order to clarify the conception of Nearly-Zero-Energy small and medium-sized office buildings in Guangzhou,this paper put forward three aspects of the annual cooling demand,the cooling and lighting energy consumption,and the ratio of renewable energy.The main research work is as follows:(1)This essay constructed a typical office building model as the benchmark building according to the Design standard for energy efficiency of public buildings GB 50189-2015.This essay use EnergyPlus and GenOpt to optimize the annual cooling demand of the benchmark building by the thermal parameter of the building envelope,internal heat disturbance and the natural ventilation.Firstly,the thermal parameters of the building envelope are optimized based on the benchmark building.The optimization result is that the annual cooling demand of the building is 85.57kWh/(m~2·a),and the energy saving rate is12.64%.Then,based on the benchmark building,considering of using natural lighting to replace part of the artificial lighting,and setting two lighting control modes,the annual cooling load of the building after optimization of the thermal parameters of the enclosure structure under the“On/Off”and“continuous dimming”control modes were 83.85kWh/(m~2·a)and 79.64kWh/(m~2·a),the energy saving rates were 14.39%and 18.69%,respectively;Secondly,natural ventilation was used to reduce the annual cooling load based on the benchmark building.The optimized result was 83.34 kWh/(m~2·a),the energy saving rate is14.92%.Finally,considering the effects of all three,the optimization result is70.65kWh/(m~2·a),and the energy saving rate can reach 28%;(2)Based on the benchmark building,the power generation of the building photovoltaic system is analyzed;Two state are considered,namely ideal state and obstructed state,and the effective power generation area is calculated based on the sunshine hours and the solar radiation,and then PVsyst is used to calculate the power generation amount.In the ideal state,the total power generation of the benchmark building is 177674kWh,and the annual power generation per unit floor area is 23.93kWh/m~2.In the obstructed state,the annual power generation is 102501.8kWh,and the unit building area power generation is 13.80kWh/m~2;(3)According to the cooling load and lighting optimization strategy,seven small-and medium-sized office buildings were selected as samples to simulate the cooling load and lighting energy consumption,and the normality test was performed on the sample data using Origin 8.5 software,the mean cooling load of small and medium-sized office buildings is73.98kWh/(m~2·a),the standard deviation is 2.29kWh/(m~2·a),and the average energy consumption of lighting is 4.70kWh/(m~2·a)and the standard deviation is 1.02kWh/(m~2·a);Considering the EER of 3.8,the cooling and lighting energy consumption limit is25.29kWh/(m~2·a);(4)Analysis of the energy consumption by segment of an office building in Guangzhou combined with related studies to determine that the total energy consumption of air-conditioning in small and medium-sized office buildings in Guangzhou accounted for 40%,and the energy consumption for lighting accounted for 20%;The guide value of Energy consumption standard for office building,firstly reduced by 50%and then split based on the proportion,to determine the cooling and lighting energy consumption limit of 19.5kWh/(m~2.a);(5)Finally,combined with the analysis of simulated data and the current energy consumption standard,the Nearly-Zero Energy building consumption index of small and medium office buildings in Guangzhou is as follows:1)The annual cooling demand per unit area is not more than 74kWh/(m~2·a);2)The annual cooling and lighting energy consumption(excluding renewable energy supply)is not more than 20kWh/(m~2·a);3)The proportion of renewable energy is not less than 20%(used for air-conditioning lighting).