Study On The Applicability Of The Hot Film-Heat Flow Meter Method Of Wall K Value Detection

With the rapid development of our country’s economy, People’s living environment quality requirements becomes higher and higher with the sharp rise in the building energy consumption year by year, Work quickly and strong is particularly important in the present. Field testing of building envelope heat transfer coefficient K value as an important part of the work of building energy saving. It has an irreplaceable role for the new building energy consumption evaluation. The traditional detection method of heat transfer coefficient of wall for buildings in northern heating areas, Detection for southern no heating areas are still no existing regulations support.This paper is mainly to test the applicability of the method which put forward by predecessors through experiments and numerical simulation. The main research contents are as follows:(1) Choosing seven walls of different thermal inertia index type, FLUENT is used to simulate the wall heat transfer of using the hot film-heat detection method in the summer typical day, The stable time of heat transfer and the detection accuracy of the results of different thermal inertia index and thermal insulation type walls is obtained. Getting the applicability of the hot film-heat flow meter method in different seasons and walls.(2) In the light of effects of solar radiation on the detection process, Thermal radiation is used to research this problem. Measurement of the thermal radiation intensity and absorption coefficient of the wall through globe thermometer and thermal comfort instrument under the globe thermometer principle. Study on the heat transfer process and the detection precision in different heat transfer temperature and in the same amount of heat radiation.The experimental results show that in the thermal radiation interference conditions can improve the detection accuracy of the results to a certain extent.(3) Using numerical simulation method to study the applicability of the hot film-heat detection method in Chengdu summer.The results of numerical simulation and the experimental results are in good agreement, Showing that the solar radiation improve the accuracy of test results of using the hot film-heat detection method, The effects of solar radiation on detection can not be considered.(4) Study on the heat transfer process in different types of wall and different convective heat transfer coefficient under the hot film-heat flow meter method.Getting the influence of outdoor wind speed on the wall detection process indirectly. The calculation results show that the temperature difference of heat transfer under different wind speed has little effect on the results and it can be neglected in the detection process.