Investigation On Comprehensive Thermal And Humidity Performance Of Exterior Wall Based On Composite Hygroscopic And Thermal Insulation Mortar

The continuous improvement of the quality of life of the people in the country,the pursuit of better indoor environment comfort,affecting the indoor environment suitability,including temperature and humidity,a reasonable external protective structure can effectively play a role in thermal insulation,energy conservation,The hygroscopic material can effectively improve the suitability of the indoor wet environment.Based on the energy-saving and comfortable indoor environment construction,this paper takes a new composite hygroscopic and thermal insulation mortar as the research object,and studies its heat and humidity performance.The main research contents are as follows:Firstly,according to the unstable heat transfer state of the wall in the hot summer and cold winter area,the double-sided heat flow meter method was used to test the fluctuation of the parameters of the four groups of typical wall.The results show that the heat flow outside the outer wall of the excessive season fluctuates with the outdoor environment,but the inner side The heat flow is very small,reflecting the role of th e external wall’s heat storage capacity in an unsteady environment;the same main wall structure,The average heat flux of the inner surface of the wall with the hygroscopic and thermal insulation mortar and the ordinary wall was 1.26 and 1.51 W/m~2,respectively.In order to verify the effect of mortar on the wall,the hot box-heat flow meter method was used for on-site inspection.The heat transfer coefficients of the two walls are 2.08 and 1.70 W/m~2K,respectively,and the test result deviation was 6.1%.The wall with hygroscopic and thermal insulation mortar is 12.6%.The COMSOL Multiphysics finite element software building material thermal-wet coupling model was used as a numerical calculation tool to simulate the moisture absorption and desorption of three different hygroscopic materials and ordinary mortar.The results show that the moisture absorption and desorption capacity of the hygroscopic material is much larger than that of ordinary mortar,maintaining a long-term high-rate absorption and desorption state;after adding hygroscopic thermal insulation mortar to ordinary clay brick,the results show that in the five typical urban simulation calculations of different zones,the wall after energy-saving transformation can effectively save 22.31～23.85% of annual energy consumption,while the proportion of energy consumption shows that the proportion of latent heat load in summer is large,and the winter is small.The calculation of energy consumption cannot ignore the influence of latent heat load.In addition,the wall orientation was studied,and the conclusions indicate that the summer is affected by the orientation factor more than the winter.Combining the advantages of internal insulation and external thermal insulation system,and considering the appropriate indoor environment,the outer wall structure of the thermal insulation board-block-inner-conditioning humidity-insulation mortar is designed.Based on the external wall structure,the durability of the winter and summer sections was analyzed.The results showed that the moldy position was at the junction of the external thermal insulation and the external plastering mortar,while the internal and external thermal insulation method had a mildew risk of 7.3%lower than that of the single external thermal insulation method.To improve the traditional energy consumption calculation method,the wall heat storage and latent heat load are considered,the heat and moisture coupling model is used to calculate the running energy consumption,and the relationship between the thickness of the insulation layer and the annual energy consumption is fitted,and the life cycle of the outer wall is The energy consumption is the optimization goal,and the optimal insulation layer thickness combination strategy of five typical cities in different districts is obtained.Considering the orientation factor,the maximum thickness difference of each city orientation is between 2.8 and 5.0 mm.It is recommended to consider the main orientation factor and choose rationally.Optimal thickness saves energy.Based on the actual test,this paper analyzes the heat transfer law of typical wall in hot summer and cold winter area.The field test verifies the improvement of the thermal performance of the wall by the humidity control mor tar.Based on this,the traditional wall(without insulation,the external thermal)insulation combined with the applicability of the new composite hygroscopic and thermal insulation mortar provides a theoretical basis for the promotion of composite hygroscopic and thermal insulation mortar.