Research on the Unsteady Evolution Mechanism of Internal Pressure in Ultra-High-Speed Double-Car Elevators Under Differentiated Ventilation Modes

Abstract Due to its unique hoistway design and operation mode, the internal pressure of a double-car ultrahigh-speed elevator fluctuates sharply with changes in speed and during intersection movement, causing passengers to experience discomfort such as tinnitus and dizziness. Based on the transient internal pressure characteristics of the car, this study proposes an elevator ride comfort evaluation standard. By analyzing the evolution law of the external field pressure of the car through numerical simulations, the study examines how the position, number, and area of ventilation holes affect the internal pressure of the car under natural ventilation. It further compares internal pressure variations between natural/mixed ventilation and exhaust/intake modes. The results show that changing the position of ventilation holes has different effects on ride comfort. Increasing the number of bottom ventilation holes (from one pair to four pairs) can reduce the pressure change rate by 53.49%, while increasing the number of top ventilation holes increases it by 101.43%. Increasing the cross-sectional area of ventilation holes reduces the comfort evaluation standards. In the exhaust mode, an increase in speed significantly increases the internal pressure (when the speed rises from 1 m/s to 4 m/s, the maximum internal pressure during the intersection process increases by 58.79%), however, the rate of pressure change and the amplitude of the change decrease. In the intake mode, the internal pressure is lower than in the exhaust mode, and increasing the intake speed further reduces the internal pressure.