Energy Consumption Test And Energy Saving Optimization Of Assembled Low Energy Consumption Residential Buildings In Cold Regions

In the face of today's construction industry's pursuit of energy saving and emission reduction and the ability to take into account the development trend of comfort,combined with the experience gained by foreign countries such as Europe,America,Japan and other developed countries in building energy conservation research,it is concluded that prefabricated buildings and low-energy buildings have gradually become The main development trend of buildings in the future,but there are few studies on the integration of the key technologies of the two new buildings,especially on the assembly of low-energy houses in cold areas combined with climatic conditions,although some pilots have been built The project,but lacks a certain follow-up to the actual operation effect,quantitative statistics can not be achieved on the actual energy saving situation,and some problems have also been found in some case projects,resulting in the phenomenon that the low energy residential standard cannot be reached after the building is completed.According to this phenomenon,taking a prefabricated house that does not meet the low-energy standard after being completed as an example,a study on prefabricated low-energy buildings adapted to cold regions is conducted.First,select the prefabricated low-energy residential buildings located in the cold climate area,analyze the calculation of the building envelope structure and its heat transfer performance,and compare it with the indicators of the low-energy building energy-saving standards in the cold area to determine that the building conforms to the climate characteristics The design goal of assembly-type low energy consumption.Secondly,the principle of indoor environment monitoring is to quantify the energy consumption of buildings while ensuring the functions and indoor comfort of buildings.Based on this principle,the four indoor environment monitoring indicators that have the greatest impact on human comfort are determined:temperature,humidity,CO₂concentration,and PM_2.5.5 concentration.The indoor environment monitoring system was used to monitor from 11:30 on August 3,2018 to 22:30 on August 16,and the monitoring results showed that the indoor temperature was basically maintained between 20?and25?,and the indoor humidity except rainfall reached the peak of 62.1 In addition,most of the time period does not exceed 60%,the CO₂ concentration is basically between70-600ppm,PM_2.5.5 concentration is exceeded by the external environment and construction,and the indoor environmental quality indicators basically meet the indoor environmental requirements of low-energy buildings The results of energy use monitoring found that the building energy consumption was 34.59%higher than the calculated value.Thirdly,according to the phenomenon that the measured building energy consumption is too large,and after analyzing the factors that affect the building energy consumption,an experimental test plan for building air-tightness,building envelope thermal defects,and external wall heat transfer coefficient test was developed.Using the DG-700 air-tightness test system for building envelopes,the overall air-tightness test of the case project was carried out,and the number of air changes at a pressure of 50 Pa was measured to be 0.795 times.The gap caused by the gap under normal operation was calculated.The energy loss is 36.53-54.80W.The Flir B200 thermal imaging camera was used to detect the thermal defects of the building envelope,and the three typical cases of the normal non-thermal defects,the linear gap defects of the module splicing and the doors and windows were compared and analyzed Thermal defects,calculated that the increase in energy consumption caused by thermal defects is 3%.The temperature control box-heat flow meter method is used to test the heat transfer coefficient of the external wall of the building,and the test value is compared with the calculated value.After analysis,the measured value of the heat transfer coefficient is 4.04%larger than the theoretical calculated value.Finally,according to the above problems,the corresponding solutions are put forward,and the optimized scheme is simulated and analyzed with TH SWARE energy-saving series software to explore whether the optimization scheme is reasonable.The improvement of the overall air tightness of the building is mainly through the setting of continuous air tight layer in the inside of the building and the air tightness treatment of linear gaps and door and window openings.The simulation results show that the building energy consumption is reduced by 11.5%when the air tightness of the case project is increased by 24.5%.This paper analyzes the thickness of thermal insulation layer which can meet the energy efficiency index of low-energy buildings in cold area,and studies the shape coefficient,the ratio of windows to walls and the sun shading of doors and windows which affect the energy consumption of buildings,and puts forward the design scheme of assembled low-energy housing suitable for cold area.