Abstract:

In order to study the influencing factors of temperature field of tunnel fire pipeline and explore a kind of thermal insulation measure in consideration of both energysaving and efficient, the study is carried out by taking Jinpenwan tunnel as engineering background. First, the heat preservation characteristics of fire pipelines in electric tracing system and fixed point heating system with micropressure circulation are compared and analyzed by combining theoretical calculation and 3D numerical simulation. Then, through theoretical calculation of fire pipelines under steady heat transfer, the two insulation modes are established to analyze the influencing factors of energy consumption. Last, the unsteady temperature field of fire pipelines in tunnel is simulated by Fluent. The results show that: (1) The required energy consumption of electric heat tracing system and micropressure cycle fixedpoint heating system are approximately the same. (2) Outside cold air enters the fire pipe gallery through the gap between cover plates, causing the temperature near the fire water pipe reduce and the heat loss increase. So it is necessary to reduce the gap between the cover plates of the fire pipe gallery. (3) Theoretical calculations can quickly and simply obtain the power required for auxiliary heating, and numerical simulation can take into account the variation of auxiliary heating power and more structural details during unsteady heat transfer process. 

Key words:

highway tunnel, fire pipeline, unsteady heat transfer; thermal insulation measure, electrical heat tracing system, micropressure cycle fixedpoint heating system