Research On Energy-saving Envelope Technology Of Rural Existing Residential Buildings In Cold Region

In cold areas,the awareness of building houses according to energy-saving standards in rural areas is relatively weak,and most houses do not adopt thermal insulation measures for the enclosure structure,resulting in outstanding building energy consumption.The heat storage performance of wall and roof is poor,resulting in serious heat loss in the interior;the improper sealing of doors and windows enlarges the frequency of heat and cold exchange between indoor and outdoor.the heating equipment usually uses coal stoves,which is simple and inefficient;these factors causes a large waste of energy in residential buildings,and the heating energy consumption in winter is the most prominent.Therefore,it is necessary to carry out energy-saving renovation of existing rural houses in cold regions,improve energy utilization efficiency,enhance the thermal performance of the enclosure structure and improve the quality of the indoor thermal environment.This paper selected a typical rural house built in the cold area in the 1990s as the research object.In the deep winter period,the typical residential buildings were inspected for building thermal defects,thermal performance of enclosure structure,heating heat consumption and indoor and outdoor temperature.The energy consumption status of the residential buildings was analyzed and the energy saving potential of the buildings was evaluated.The measured results showed that the thermal performance of the external walls and roofs of typical rural residential buildings in cold areas was poor,and the rate of heat transfer coefficient exceeding the standard was 162.92%and 207.2%respectively,the air tightness of doors and windows was insufficient,and there were thermal defects;the energy utilization rate was low,the heating heat consumption was 44.67W/m~2;the indoor thermal environment was extremely unstable,the average temperature reaching the standard rate was only 27%,and the potential of energy-saving renovation of houses is great.Secondly,the effective heat transfer coefficient method was used to calculate the heating energy consumption of typical rural residential buildings in static theory.The proportion of heat consumption in each part of the enclosure structure was analyzed,and the key reconstruction parts of the buildings were determined,which can provide reference for the energy-saving transformation of existing rural residential buildings in cold areas.The analysis results showed that the heat consumption of typical rural residential buildings was as high as 55.19W/m~2,and the phenomenon of heat loss was prominent;the heat transfer and heat consumption of the enclosure structure was the main factor affecting the energy consumption of the building,in which the proportion of heat consumption of exterior walls and roofs was 86.81%;the heat consumption caused by air infiltration of doors and windows was much larger than the heat transfer caused by excessive heat transfer coefficient;the heat consumption of buildings was from large to small was:exterior walls,roofs,air infiltration,grounds and outer doors and windows.Finally,the energyplus energy simulation software was selected to dynamically calculate the heating energy consumption before and after the energy-saving renovation of typical rural residential building envelopes,and the simulation results were analyzed and evaluated in three stages.The results shows that the energy-saving rate of existing rural residential buildings after comprehensive renovation is above 71%;meeting the energy saving target of 65%in cold regions;the phase change mortar is more energy-saving for plastering the walls,and the indoor thermal comfort is the best;the rigid polyurethane foam is used as the roof insulation material,the cost recovery period is shorter;the ground plastering should be replaced by 20mm paraffin/graphite composite phase change mortar with the same thickness of cement mortar;the plastic steel window frame is better than wooden window,the optimal choice for windows is double-layer Low-e hollow glass window(3C+6A+3C),and the door is best selected with polystyrene insulation door.