Ventilation
shafts are often required to solve the construction ventilation problems in
extralong tunnels or multiple working faces in tunnels with a single
slope. To investigate the factors affecting the ventilation of the shafts, the
vertical tube is used to replace the shaft, it is assumed that the temperature
of the wall changes linearly along the shaft, and the expression of the average
wind speed of the steadystate airflow in the shaft
section with heat source is derived subsequently. Then, the expression of
demanded ventilation volume for shafts is obtained using Taylor series. The
results reveal the following: (1) When the atmospheric pressure 〖WT５《TNR#I》〗P〖WT５《TNR》〗a5 at the tunnel entrance is consistent with the change of the
atmospheric pressure 〖WT５《TNR#I》〗P〖WT５《TNR》〗a1 at the shaft orifice, the difference
between the two will not affect the construction ventilation of tunnel. (2)
When the changes of 〖WT５《TNR#I》〗P〖WT５《TNR》〗a5 and 〖WT５《TNR#I》〗P〖WT５《TNR》〗a1 are not
synchronous, the increase of the difference (〖WT５《TNR#I》〗P〖WT５《TNR》〗a5-〖WT５《TNR#I》〗P〖WT５《TNR》〗a1) will result in the decrease of the inlet air volume of the shaft.
(3) The wind pressure required by the fan located at the bottom of the shaft
decreases with an increase in atmospheric temperature at the orifice, and
increases with an increase in the stratigraphic temperature. (4) When the
environmental parameters and working conditions are specified, the shaft
ventilation rate expression can be used for quantitative analysis, which is
conducive to fan selection and intelligent control of fan operation.
LIU Shilei, TONG Yao, WANG Shugang
. Determination of Ventilation Volume for Special
Ventilation Shafts of Tunnel Construction and Its
Influencing Factors[J]. Tunnel Construction, 2022
, 42(S1)
: 104
-111
.
DOI: 10.3973/j.issn.2096-4498.2022.S1.012
