Numerical simulation of ventilation and dust suppression system for open-type TBM tunneling work area

• Airflow and dust flow characteristic equation models were established.
• Simulation models were established using CFD software.
• The model effectiveness was validated by site test.
• The optimum main vent location, air baffle length, etc. were determined.

In order to study the characteristics of the ventilation and dust suppression system for open-type TBM tunneling work area in a Ø8.53 diversion project, the numerical simulation method is adopted, and a three-dimensional steady airflow model, a dust flow model as well as other related flow characteristic equation models are established by considering the dust production mechanism of TBM construction. Besides, corresponding simulation models validated by experiment are established using CFD software, and the impacts of the main vent location, the air baffle length in the main beam and the exhausting air flow quantity on flow field distribution and dust flow behavior in open-type TBM tunneling work area are investigated. The results show: when the main vent is located 70–80 m away from the working face, the ventilation in TBM tunneling work area is optimal; when the air baffle is as long as the main beam, the dust collection efficiency is the highest, reaching 89.4%; under the condition that the exhausting air flow quantity is less than half of the ventilation air flow quantity required by energy consumption and the minimum backflow velocity, the best dust suppression effect can be achieved when the exhausting air flow quantity is 40% of the ventilation air flow quantity.