Heat exchange on the outside of the pipe when heat is distributed by heat networks

The article deals with the exchange of heat on the outside of the pipe when distributing heat through heat networks. This is a combined heat exchange, i.e. free convection and radiation. The calculations and outputs analysed in the article are mainly applicable to thermal networks run aboveground. In the calculation, an ambient temperature of 15 °C was measured, ranging from the temperatures corresponding to the air temperatures in the channel. The results are interpreted in the form of diagrams and tables. The calculation was performed on the secondary DN 125 pipe with PIPO_ALS insulation and the calculation was extended to all nominal diameters used in the secondary wiring for determining the influence of heat transfer, depending on the change in pipe diameter