Validation of the DESC Code in Simulating the Effect of Vent Ducts on Dust Explosions

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• 作者：Diana Castellanos ; Trygve Skjold ; Kees van Wingerden ; Rolf K. Eckhoff ; M. Sam Mannan
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：May 1, 2013
• 年：2013
• 卷：52
• 期：17
• 页码：6057-6067
• 全文大小：682K
• 年卷期：v.52,no.17(May 1, 2013)
• ISSN：1520-5045

文摘

The computational fluid dynamics (CFD) code DESC has been used to simulate a series of dust explosion experiments performed in an 18.5 m³ vessel equipped with vent ducts of varying cross sections and lengths. The motivation behind the work is 3-fold: to validate the CFD code, to gain increased understanding of the parameters affecting dust explosion venting through ducts, and to investigate the validity of empirical correlations found in various standards and guidelines for design of explosion protection systems. Although the results from simulations agree reasonably well with experimental observations, DESC tends to underpredict the reduced explosion pressures for scenarios with vent ducts with diameters significantly larger than the vent openings. These discrepancies may be a result of inherent limitations in the model system, but poor repeatability and limited access to detailed experimental data complicates the analysis. Results from experiments and simulations are compared with predictions from various standards and guidelines for design of vent ducts in industry: EN 14491, VDI 3673, NFPA 68, and the methodology developed by FM Global. The correlations in NFPA 68, derived from the same set of experiments in the 18.5 m³ vessel, yield the most accurate predictions. The FM Global method underestimates the reduced explosion pressure for the largest vent diameter and rear ignition and yields conservative results for smaller duct diameters. Neither experiments nor simulations support the concept of a critical duct length prescribed in EN 14491 and VDI 3673.