The weight of the air column depends on its temperature and height. Therefore, as long as there is height difference and gas temperature difference, there must be natural wind pressure between tunnels connected underground. (There should be other influencing factors).

Natural wind pressure affects the ventilation system. When the direction of mine natural wind pressure is consistent with the direction of main ventilator, mine natural wind pressure is helpful to ventilation of main ventilator. When the direction of mine natural wind pressure is inconsistent with that of main ventilator, mine natural wind pressure becomes the ventilation resistance of main ventilator, thus reducing the ventilation capacity of ventilator. Please refer to related papers for details.

Natural wind pressure ventilation: use natural wind pressure ventilation. According to the "Coal Mine Safety Regulations", natural wind pressure ventilation is strictly prohibited in coal mines (the original text "All mines must adopt mechanical ventilation, and natural ventilation is not allowed." ); It is also stipulated that "when the main ventilator stops running, the mine with 1 main ventilator responsible for the ventilation of the whole mine must open the wellhead explosion-proof door and related dampers and use natural wind pressure for ventilation;"