Analysis Of Energy Consumption And Application Of Renewable Energy Of A Residential Building In Hot Summer And Cold Winter Region

With the acceleration of urbanization in China,the scale of construction industry is also expanding,which drives the increase of building energy consumption.Against this background,"near zero energy building"has gradually become the key to deal with building energy conservation because of its low energy consumption,high energy efficiency,less environmental pollution and good human comfort.Architectural design in the scheme stage is an important way to achieve near zero energy building target.In this paper,a typical high-rise residential building in Nanjing is taken as an example to study how to optimize it into NZEB.Several thermal parameters that affect the building energy consumption are selected to be optimized by using Sketch Up,Open Studio,EnergyPlus to run the simulation.According to the construction drawings and other information,the basic model is established on the software platform.Then,the energy-saving optimization design is carried out for the external wall heat transfer coefficient,roof heat transfer coefficient,external window heat transfer coefficient and external window solar heat gain coefficient within the set threshold range.The contribution rate of energy saving is taken as the index to analyze the energy saving effect of each parameter.Then,the sensitivity analysis is applied to find out which thermal parameters have great influence on the building energy consumption,and from this,the most energy-saving scheme is determined.On this foundation,photovoltaic system and ground source heat pump system are applied to further improve the overall energy-saving performance of this building,so that it can meet the goal of NZEB.Research shows:(1)SHGC value of exterior window has the greatest energy saving potential,and the heat transfer coefficient of exterior wall is the second.When the SHGC of the exterior window is 0.40 and the heat transfer coefficient of exterior wall is 0.30W/(m~2·K),the energy saving rate of the enclosure structure of the optimization model is 15.73%,and the proportion of the energy consumption of cooling and heating in the total energy consumption of the building in the whole year is reduced from 42.24%to 38.12%.(2)The best installation angles of household photovoltaic panel and roof centralized photovoltaic panel are 45.21°and 33.05°respectively.If the best installation angles are selected,the annual power generation of the centralized photovoltaic system is 11.56%higher than that of household photovoltaic system.Both of them can meet the electricity demand of 79000 k Wh in the whole year,and undertake 39.5%power demand of lighting and equipment system.(3)If the building cooling and heating source system is replaced by household ground source heat pump system,the cooling energy consumption per unit floor area can be reduced by 23%when the heating energy consumption can be reduced by 25%.The coefficient of performance of the ground source heat pump system can be kept at about 4 in summer and about 3in winter.(4)After optimization of thermal performance of enclosure structure,photovoltaic system design and house type ground source heat pump system design,the total primary energy consumption per unit floor area is 51.171kwh/(m~2·a),which is 35.2%lower than the original building model,and the energy substitution rate of photovoltaic system is 23.7%when the contribution rate of GSHP is 38.76%,which meets the national standard of NZEB.It is an effective way to reduce the building load by setting the proper limit value of the thermal parameters.To achieve zero energy consumption,it is also necessary to take active energy-saving technical measures to improve the operation efficiency of energy equipment and make full use of renewable energy.This paper provides a reference scheme for the design of nearly zero energy residential buildings in hot summer and cold winter regions,provides theoretical support for the promotion and application of household photovoltaic system and household ground source heat pump system,and also has positive significance for building energy saving.