Research On The Thermal Bridge Of Cavity Wall Concrete Column In Hot Summer And Cold Winter Zone

With China’s increasing emphasis on building energy-efficient, combing our country in recent years in-depth study on the building envelope thermal bridges, this article uses the integrated use of two devices in the laboratory, in-depth research on such test methods as well as sandwich wall concrete columns thermal bridges are made, the main contents:1.Feasibility of the use of1. JTNT-A with both the JTR-G envelope structure detection equipment. Comparative Tests of the integrated use of both devices.The short wall was puzzled in the specimen rack devices specimen, long masonry wall puzzled in the test room.JTR-G equipment, cold box and hot box were used to manufacture a stable thermal environment on both sides of the wall.After data processing:during testing the short wall on the equipment rack, temperature and heat flux readings of it have relatively faster changes than that of long wall, needed shorter time to achieve stabilize. But in the final steady state, the readings of both temperature and heat flux tends to be the default value. This shows that JTNT-A and JTR-G two building envelope testing equipment use is feasible, can provide a reliable and real data for detection of the wall heat transfer coefficient.2.In-depth research on two improvements at the the wall of the concrete columns are be made. XPS insulation board are added to the Column wall junction of second paragraph of the wall, insulation mortar is wiped outside of the third wall column,and then both of them seem as the test points.The data obtained show that the above process can effectively reduce the average wall heat transfer coefficient.The study shows that, in the steady-state thermal environment, the wall temperature difference reached15℃, two improvements can reduce the impact of the effect of thermal bridges, adding XPS insulation board is better than wiping insulation mortar outside of the lateral pillar. The measures entirely favorable to for the promotion of building energy efficiency and existing buildings, building energy saving.3.Concrete columns at the sphere of influence of thermal bridges were tested. Through Changing the arrangement of the measuring point, the thermal performance of data analysis obtained:30cm away from the column at the outside, the heat flow and temperature changes are less obvious, and slightly higher near the column at (30cm) of data. This shows that the concrete columns have a certain impact on the average heat transfer coefficient of the wall and sphere of influence of the thermal bridge is mainly distributed on both sides of30cm within.The thermal bridge results and conclusions at the parts of sandwich wall concrete column show that:In the summer and cold winter areas JTNT-A and JTR-G two building envelope testing equipment capacity is feasible for the detection of wall heat transfer coefficient. Two improvements can reduce thermal bridge of sandwich wall concrete columns and energy saving of the existing building has a certain validity and reference.