The Analysis Of Heat Transfer About Thermal Bridge Beside Windows In The Enclosure Of Multi-story Building

In the present criterion of our country, the effect caused by the thermal bridge beside the windows is not given consideration in calculating the average heat transfer coefficient of walls and heat transfer coefficient of windows, which is not neglectable. According to the rule 4.3.5 in "Criterion for Thermal Capability of Residential Buildings"(GB50176-93), the checking computations of the temperature field for inner surface temperatures of the thermal bridge caused by windows should be done.In this paper, the FLUENT numerical simulation software are adopted to simulate the temperature field of the actual wall, which directly shows the temperature distribution of the computational zone's and heat flux. By analyzing temperature field in detail, it was concluded that the middle temperature of the heat flow meter could be used to represent the temperature of the position measured for calculating the heat transfer coefficient, because the temperature in the building envelops of Dazhongxincheng residential area and Baimao residential area was in the range of the heat flow meter, also nearly linear. Nevertheless, the analysis indicated that the temperature in energy-saving walls close to windows in steamer factory's residential area was not linear. All the conclusion mentioned above can provide theoretical bases for the test. Meanwhile, the scope of effect caused by the thermal bridge around the windows could be accurately estimated from the simulation results.On the basis of the analysis, the heat flow meter approach was used to detect the heat flux of walls beside the windows and temperatures of the inner surface and the outer surface in correspinding positions. According to these above, the heat transfer coefficient of each position measured was calculated, and the scopes of effect caused by the heat transfer of walls beside windows and the thermal bridge were analyzed. It was derived from analysis that the scope of effect caused by of thermal bridge energy saving walls in Qilunji factory's residential area was the least one. The accuracy of the theory model and the computational results was validated from applications, also the reference was provided for the development of numerical simulation in heat transfer.In this paper, the unsteady-state thermal performance of walls beside windows was simulated with the temperature outside changing periodically. Additionally, the time delay and damping factor of walls were studied, which are the physical parameters that can show the thermal stability of walls.