Theoretical study on ventilation and heat transfer of uti

The rectangular structure utility tunnel is equivalent to a cylindrical structure, the effects of soil heat conduction resistance, wall convective heat transfer resistance and internal heat sources on the ventilation and cooling of the utility tunnel are comprehensively considered, and a one-dimensional steady-state heat transfer mathematical model of the utility tunnel is established. The analytical expression of the ventilation speed is obtained, and the heat transfer ventilation volume of the utility tunnel can be calculated with the simple Excel iterative calculation. After considering the wall heat transfer, the mechanical ventilation volume is obviously lower than that of wall adiabatic ventilation. The factors affecting the ventilation speed and volume of the utility tunnel are analysed. The factors with significant influence on the ventilation volume are the calorific value of the internal heat source and the outdoor air temperature.