TY  - EJOU
AU  - Li, Xiaolong 
AU  - Chen, Hui 
AU  - Liu, Yingwen 
AU  - Yang, Peng 

TI  - Numerical Analysis of Non-Uniform Pollutant Distribution in an Internal Space of Tank and the Efficacy of an Active Purification Strategy
T2  - Frontiers in Heat and Mass Transfer

PY  - 2025
VL  - 23
IS  - 6
SN  - 2151-8629

AB  - Hazardous gas intrusion in tightly sealed and geometrically complex confined spaces, such as armored tanks, poses a critical threat to occupant health. The intricate internal structure of these systems may lead to non-intuitive pollutant transport pathways. However, the spatial and temporal evolution of these structures, as well as the intrinsic mechanisms of the purification systems, remain poorly elucidated. In this study, a high-fidelity, transient three-dimensional computational fluid dynamics (CFD) model was developed to simulate the leakage and dispersion of carbon monoxide (CO) and nitrogen dioxide (NO<sub>2</sub>) using the RNG k-ε turbulence model. Scenarios with and without an active purification system were systematically investigated under four leakage rate conditions: 0.33, 0.66, 1.32, and 2.64 m·s<sup>−1</sup>. Our results reveal that, flow recirculation driven by the compartment’s geometry leads to the formation of stable, high-concentration “hazard zones”. Following the activation of the purification system, <mml:math id="mml-ieqn-1"><mml:msub><mml:mrow><mml:mtext>Log</mml:mtext></mml:mrow><mml:mrow><mml:mn>10</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mtext>CV</mml:mtext></mml:mrow></mml:math> decreases from 1 to 0.1, demonstrating that the primary value of the purification system lies in homogenizing the internal flow field and minimizing localized hazardous zones. At leakage rates below 1.32 m/s, the purification system ensures pollutant concentrations at all monitoring points are effectively controlled below limitation. When single-pass purification efficiency increases from 25% to 30%, pollutant concentrations at critical monitoring points decrease by approximately 30%. This work provides crucial mechanistic insights and a quantitative basis for the design of advanced ventilation systems in complex confined environments, advocating a design philosophy shift from simple air exchange to strategic flow-field management.
KW  - Hazardous gas; leakage and diffusion; purification strategy; CFD; confined space; flow homogenization

DO  - 10.32604/fhmt.2025.070537