The On-site Detection Method Of Thermal Preformance Of Exterior Walls And Results Analysis

For building energy assessment and energy saving, you need to accurately measure and control building envelope thermal performance of the status quo, the existing building envelope heat transfer coefficient analysis detection methods are reviewed. In this paper, heat flow meter method Binzhou City, a university library building exterior thermal resistance on-site testing, and the arithmetic average method for processing the experimental data, the use of the thermal conductivity of the wall FLUENT software to simulate the process, the measured circumference retaining structure and wall thermal resistance thermal resistance design values were compared, analyzed the causes of the differences, the use of numerical simulation of the wall heat conduction problem simulation analysis. Comparative analysis of the steady and unsteady heat conduction process in the case of three-dimensional wall of the analog value and the theoretical value calculated difference verify the feasibility of the calculation model; the actual measurement data as input parameters for numerical simulation of the experimental wall for unsteady numerical calculations and numerical simulation of the thermal resistance of the wall with the experimental value and the design value of the test were analyzed;application FLUENT on the wall were one-dimensional numerical analysis of heat transfer area were drawn steady heat conduction and case of unsteady heat conduction of the wall one-dimensional heat conduction area, through the transition season experiment wall thermal conductivity analysis, the field test of the season in the control of indoor and outdoor air temperature. Initially drew the following conclusions1.diurnal changes periodically based on the outdoor temperature one-dimensional unsteady heat conduction model, the numerical results obtained with the theoretical value or less, their arithmetic mean method to calculate the thermal resistance with high accuracy;2.due to the wall does not match the actual use of materials and design and other reasons, resulting in wall thermal resistance test values with the theoretical value of the difference between the calculated wall heat transfer coefficient to the measured values should prevail;3.In this experiment the wall insulation material under the scope of the thermal bridge:1.0m<y<2.5m, z<0.7m, at the measuring point selection should avoid this location;4.the calculation results show that the transition season, with the arithmetic mean method to calculate the thermal resistance of the wall to be considered when the outdoor temperature cyclical fluctuations; their indoor and outdoor air testing should be controlled at an average temperature above18"CFor this experiment, the thermal conductivity of the wall for performance analysis and results, the actual testing and on-site measuring points have a certain significance. Obviously different regions and different wall insulation materials and structure, its thermal performance analysis results are different.