Calculation of cable calorific value for utility tunnels based on load current

The utility tunnel is a closed underground structure, and the cables laid in the utility tunnel are the main heat source. Accurate estimation of the calorific value of the tunnel cable is helpful for the reasonable selection of ventilation equipment and the scientific design of the process, so as to avoid the waste of resources and costs. In this paper, a calculation method of cable calorific value based on load current is proposed, and a more accurate cable load current is obtained by analysing the cable of the bus section of the substation. Through the calculation, it can be seen that the results obtained by using the load current for cable calorific value calculation are more accurate than the results of the cable calorific value calculation using the ampacity, and the results are significantly reduced, which can reduce energy consumption and save cost under the premise of meeting specification requirements and functional needs.