A novel approach for the modelling of air quality dynamics in underground railway stations

Abstract

Indoor air quality in subterranean train stations is a concern in many places around the globe. However, because of the specificity of each case, numerous parameters of the problem remain unknown, such as the braking disc particle emission rate, the ventilation rate of the station or the complete particle size distribution of the emitted particles. In this study the problem of modelling PM10 concentration evolution is hence addressed with a particle-mass conservation model which parameters are fitted using a genetic algorithm. The parameters of the model allow to reproduce the dynamics and amplitude of the measured data and comply with realistic bounds in terms of emissions, deposition and ventilation rate.

A comparison of airborne wear particle emission models based on metro station measurements

“…According to Walther and Bogdan [20], the conservation model can be separated into three parts. The expression of the model is shown in equation (2).…”

“…For the linear model, the k and C0 values of each station were calculated by using the linear regression method. As to the conservation model, similar genetic algorithm method in [20] was used to calculate all parameters for each station.…”

“…The parameters in the conservation model were calculated by using the measurement data and following the same genetic algorithm method used in [20]. The values of all parameters are listed in Table 3.…”

“…The linear model has been used to describe the relation between PM10 and train frequency on underground platforms [5,[17][18][19]. Another model, called the conservation model (ordinary differential equation) was developed by Walther and Bogdan [20], which predicts PM10 value changing with train frequency and time.…”

Energy, economic, and environmental impacts of enhanced ventilation strategies on railway coaches to reduce Covid-19 contagion risks

“…Specifically, will be discussed first papers dealing with Indoor Air Quality (IAQ) and ventilation in the railway sector (and typically published before the Covid-19 outbreak), and then the ones investigating also the Covid-19 contagion risk (for a wider range of applications). Starting with papers regarding IAQ and ventilation in the railway sector, most of the works focus their attention on the infrastructures, such as stations and subway tunnels [ 7 , 8 ], rather than on the railway carriage. In fact, except the works adopting a CFD approach, such as the one reported in Ref.…”