Effects of Smoke-Dust and CO on Controllable Circulatory Ventilation of an Extra-Long Highway Tunnel: Theoretical Model and Calculations

The complexity, high energy consumption, and difficulty in controlling of extra-long highway tunnel have always been problematic in the civil engineering field. The objective of this study is to discuss controllable circulatory ventilation (CCV) considering these issues. By calculating the equations of consumed air volume (CAV), diluting smoke-dust and CO, this study deduces the theoretical dimensionless equations governing the influence of two pollutants’ CAV on CCV application. By setting the vehicle speed from 10 km/h to 80 km/h and setting the slope from −4% to 4%, engineering data of Jiaozhouwan tunnel, for example, the abovementioned equations of environment ratio, load ratio, and critical diesel-gasoline ratio, were calculated numerically. Furthermore, the effects of smoke-dust and CO on CCV were quantified. Drawn from this study, the critical diesel-gasoline ratio can be a key indicator to the preassessment of CCV application to an extra-long highway tunnel