Feasibility experiment on the simple hot box-heat flow meter method and the optimization based on simulation reproduction

This paper proposes a simple hot box-heat flow meter method (SHB-HFM) and verifies its feasibility by an in-situ measurement of wall thermal transmittance. The experimental results show that even under very unfavorable test conditions, the test error of the wall thermal transmittance by the SHB-HFM is only −5.97% relative to the design value, which proves that the SHB-HFM has the adequate test accuracy, thereby proving that this method is feasible. And through arranging reference test sensors, 15 cm up and down from the central primary test sensors, the test errors due to location deviation increase to −8.14% and −9.60% respectively, which basically meets the accuracy requirement and thereby demonstrates the SHB-HFM has an acceptable tolerance for the in-situ operation. To further explore the influence of various factors on the test accuracy, a mathematical model is established and verified by the experimental data. The simulation results indicate that the perfect in-situ measurement conditions do not improve the measurement accuracy obviously, while moderately enlarging the box dimensions or simultaneously arranging heat flow meters on the inner and outer surfaces is more effective in improving the test accuracy.