Heat loss along the pipeline and its control measures

In this study, we present the derivation of the formulas for calculating the temperature drop and heat loss along the heat transporting pipeline and the methods of controlling the heat loss. Our results show that, both the temperature drop and the relative heat loss increase with the pipeline length, and increase close to linearly; the relative heat loss is nearly proportional to the thermal conductivity and is inversely proportional to the insulation thickness; the relative heat loss along or across the pipeline decreases with the increase in pipeline diametre, initial temperature, flow velocity or surrounding temperature. And we can control the relative heat loss within a determined range, even less than 10%. Especially, some thermal problems of the pipeline can be easily handled. Reducing its heat loss by 50%, for example, can be achieved by doubling the insulation thickness or by cutting down the thermal conductivity by half. As well, the causations of all the results are exhibited in detail. Highlights Formulas are derived to calculate temperature drop and heat loss, and the causations of all results are shown in detail. Relative heat loss increases almost linearly with the pipeline length, thermal conductivity and reciprocal of insulation thickness. Relative heat loss decreases with the pipeline diametre, initial temperature, flow velocity, surrounding temperature.