Analysis of Natural Convection of Horizontal Cylinder Circular Tubes in Polar Environment

Electric heat tracing is an important way of insulation and anti-freeze for polar engineering equipment. Natural convection is a key factor affecting heat transfer of the electric heat tracing system. In this paper, an experimental device simulating a polar low-temperature environment was designed and built to measure the natural convection heat transfer of horizontal circular tubes. The temperature range was −51.7 ~ 0.7 ℃, and the heating power range was 0.5 ~ 21.1 W. Influence of heating power and ambient temperature on the natural convection heat transfer coefficient was analyzed under heating conditions with constant heat flow. Based on the experimental data, an experimental criterion of the average Nusselt number applied in the range of 3 790 © 2023 Editorial office of Ship Building of China. All rights reserved.