Field measurement on transient carbon monoxide levels in vehicular tunnels

Influence of Traffic Flow Patterns on Air Quality inside the Longest Tunnel in Asia

“…Pierson (1996) investigated the main air pollutant concentration in the Tuscarora Mountain and Fort McHenry Tunnel from 1992 to 1993 and found that the air pollutant concentration in the tunnel was 12-14 times higher than that in ambient air. In Asia, Chan et al (2002) and Chow et al (2003) monitored the air quality in a road tunnel in Hong Kong from [2002][2003] and determined that the CO concentration was in the range of 8-28 ppm. He et al (2008) reported a comprehensive characterization of PM 2.5 emissions in the Zhujiang Tunnel in the Pearl River Delta region of China.…”

Theoretical predictions and field measurements for potential natural ventilation in urban vehicular tunnels with roof openings

“…If the replenishment of stale air is efficient, the internal temperature of the tunnels will be extremely close to the outdoor air temperature. It is difficult to conduct the field measurements in operating tunnels, only a few researches [12,22,24,27,28] can be found: the measuring trees were setup at a straight section of the draught relief shaft of the Taipei subway station [22]; a measurement system had been built to measure the traffic flow and the induced wind speed in the Fu-De Tunnel for 4 years before the highway was opened, and a remote data acquisition system was added in the fourth year [24]; an SF6 tracer was used to measure the ventilation flux of the tunnel [27]; concentrations of CO, NO 2 and SO 2 were measured using a manual air sampling analyzer which were conducted at one location at tunnel midpoint [28]. In this study, a measurement system was not built and fixing instruments on walls or ceiling was not approved; testers had to enter into the tunnels and held the instruments to record parameters as that of [12].…”

“…Fifteen trips were conducted from November 2013 to January 2014 in the 5 tunnels, which were known as continuous measurements [12]. The instruments were placed in a moving car with the windows opened.…”

“…It is believed that [12] CO is an indicator of air quality in the environment as a result of petrol engine emissions while NO x and particulates can be used to indicate diesel engine emissions. The acceptable limit of CO concentration depends on people's exposure time.…”

Adaptive Critic Design Based Control of Tunnel Ventilation System with Variable Jet Speed

“…In such semi-enclosed space, air quality control using mechanical ventilation systems has become a critical task to ensure good traffic operation within it. In most of these newly constructed urban tunnels where the traffic is uni-directional, longitudinal ventilation systems with jet fans are frequently used due to their high energy efficiency, low investment and relatively simple control system structure [1]. Moreover, the jet fans are equipped with frequency conversion devices, making it possible to shorten the control cycle and implement advanced control strategies by adjusting the jet speed according to different control objectives and traffic loads.…”