Research On Energy-saving Reconstruction Of Existing Public Buildings In Hefei Area

In order to cope with the future energy shortage crisis and climate change,China has proposed the energy saving and emission reduction policies of“carbon peaking”and“carbon neutral”in 2020.As a major energy-consuming industry,the construction industry has become the core area to achieve the“double carbon”goal.China has been promoting energy-efficient buildings on a large scale for a long time,and has been improving the energy efficiency of buildings by raising building energy efficiency standards,renovating existing buildings,increasing industry supervision,and promoting the application of renewable energy technologies.China has a vast land area,and the climatic characteristics vary greatly from region to region,so the technical solutions for building energy efficiency retrofits cannot be copied directly from each region,but need to be implemented individually by selecting measures that meet local standards.Based on the climate characteristics and energy-saving standards of Hefei area,this paper studies the application of common building materials in the energy-saving transformation of existing public buildings and the optimization of energy-saving transformation measures,selects a relatively suitable transformation plan,and analyzes its energy-saving effect.The main contents are as follows:First of all,this paper expounds the climate characteristics and building thermal division in Hefei area,and introduces the theory and application forms of exterior envelope reconstruction,lighting system reconstruction,HVAC reconstruction and renewable energy technology in existing building energy-saving reconstruction.The composition and characteristics of thermal insulation materials and window materials are described in detail,which provides a reference for the selection of energy-saving reconstruction materials.Then,this paper selects the energy-saving renovation project of a hospital in Hefei area as a research case.According to the energy-using defects before the transformation of a hospital,the energy-saving renovation scheme is proposed in a targeted manner.The building energy consumption calculation and analysis software PKPM-Energy is selected as the research tool.The software is used to establish the building model of the hospital for experimental simulation.Through the building energy consumption data run by the model,the single factor analysis method is used to analyze the influence of each renovation scheme on building energy consumption and load.The thickness of the insulation layer of the enclosure structure and the type of the outer window are optimized separately.At the same time,under the condition of ensuring indoor thermal comfort and local energy-saving standards,the economic and social factors affecting the energy-saving transformation of existing buildings are analyzed and evaluated,and a relatively suitable transformation scheme is selected.Finally,it is determined that the most suitable scheme for building energy-saving renovation of a hospital in Hefei is to add homogeneous modified fire insulation board（thickness of 170 mm）on the roof,add semi-rigid hydrophobic rock wool insulation board（thickness of 50 mm）on the outer wall,replace the outer window with heat-breaking aluminum alloy low radiation（6Low-E+12A+6）hollow glass window,replace the ordinary fluorescent lamp with LED energy-saving lamp and grid fluorescent lamp,replace the heating and air conditioning system with high efficiency and low noise equipment,and establish an energy consumption monitoring system inside the hospital.Finally,the energy saving effect of a hospital after transformation is calculated and analyzed.The energy saving effect is:the energy saving of the enclosure structure is 99,900 k Wh,and the energy consumption is reduced by 12.31%;the energy saving of the lighting system is 248.9 thousand k Wh,and the energy saving rate is 40.53%.The comprehensive energy saving is 348,800 k Wh,and the energy saving rate is20.43%.After the transformation,the CO₂emission can be reduced by 202.66 tons per year,and the building energy saving transformation standard in Hefei area is reached.Through the analysis of the theory and application of energy-saving renovation of existing public buildings in Hefei,we aim to solve the problem of high energy consumption in the use phase of buildings due to the lack of energy-saving design and aging of equipment,to improve the energy efficiency of buildings,to reduce the energy costs of buildings in the use phase,to maximize the energy-saving potential of buildings,and to provide reference for the energy-saving renovation of the same type of hospital buildings.