Numerical simulation on heat transfer characteristics of gas pipeline in urban utility tunnel

Abstract

Recent years, more and more utility tunnels are adopted in China with the development of urbanization. Compared to the conventional method for utility installation, the utility tunnel that co-locates more than one utility underground eliminates the need for frequent excavation and reinstatement of roads. Ventilation systems are essential in utility tunnel for safety reasons, especially for gas compartments. This paper aims to evaluate effect of the longitudinal ventilation on gas temperature field by investigating the heat transfer process on gas pipeline. Numerical models including convection, conduction and radiation were established and then used to simulate the heat transfer process on gas pipeline. Results show that the ventilation has a great impact on gas temperature. In case of low inlet air temperature, the gas temperature may drop below -10 °C, which is too low to guarantee a normal operation.