O EFEITO DA GEOMETRIA DO VAZAMENTO NA NUVEM DE GÁS INFLAMÁVEL: UMA ANÁLISE SOB A ÓTICA DA SEGURANÇA DO PROCESSO

O EFEITO DA GEOMETRIA DO VAZAMENTO NA NUVEM DE GÁS INFLAMÁVEL: UMA ANÁLISE SOB A ÓTICA DA SEGURANÇA DO PROCESSO

GODOY, C. M. de; FERREIRA, T. D.; VIANNA, S. S. V.

Artigo:

The necessity of a new jet modelling approach in safety studies has been discussed. Differences between the jet behaviour originated by different orifice shapes have been observed. The current work presents an analysis about the differences between flammable gas clouds formed by axisymmetric jets (usually used in safety studies) and high aspect ratio jets (that has been suggested by some authors as the best way to represent real leak scenarios in industry, such as flange leakage). The RANS (Reynolds Averaged Navier Stokes) CFD modelling approach is used. An offshore module was considered and a gas leak was placed into the geometry. The work is also focused on the efficiency of the computational tool ANSYS – CFX 15.0 in reproducing the high aspect ratio jets (HARJ). The results indicated the need of great computational effort in order to represent the short distance behaviour of high aspect ratio jets. Besides, it had been observed that the gas clouds originated from HARJ are formed closer to the orifice than the clouds obtained by axisymmetric jets. For HARJ, the total flammable volume is less than or equal to the volume of the clouds originated by axisymmetric jets.

The necessity of a new jet modelling approach in safety studies has been discussed. Differences between the jet behaviour originated by different orifice shapes have been observed. The current work presents an analysis about the differences between flammable gas clouds formed by axisymmetric jets (usually used in safety studies) and high aspect ratio jets (that has been suggested by some authors as the best way to represent real leak scenarios in industry, such as flange leakage). The RANS (Reynolds Averaged Navier Stokes) CFD modelling approach is used. An offshore module was considered and a gas leak was placed into the geometry. The work is also focused on the efficiency of the computational tool ANSYS – CFX 15.0 in reproducing the high aspect ratio jets (HARJ). The results indicated the need of great computational effort in order to represent the short distance behaviour of high aspect ratio jets. Besides, it had been observed that the gas clouds originated from HARJ are formed closer to the orifice than the clouds obtained by axisymmetric jets. For HARJ, the total flammable volume is less than or equal to the volume of the clouds originated by axisymmetric jets.

Palavras-chave:

DOI: 10.5151/chemeng-cobeq2014-1269-20159-150917

Referências bibliográficas

• [1] CLEAVER, R.P.; HUMPHREYS, C. E.; ROBINSON C. G. Accidental Generation of Gas Clouds on Offshore Process Installations. J. Loss Prev. Process Ind., v. 7, n. 4, p. 273-280, 1994.
• [2] FERREIRA, T. D. Developing a Mathematical Model for Prediction of Flammable Gas Cloud Size Based on CFD and Response Surface Methodology. Dissertação (Mestrado em Engenharia Química), Falculdade de Engenharia Química, Universidade Estadual de Campinas. Campinas, 2014.
• [3] LEES, F. P. Loss Prevention in the Process Industries – Hazard Identification, Assessment and Control. 3 ed. Oxford: Butterworth-Heinemann, 2005.
• [4] WAKES, S. J.; HOLDØ, A. E.; MEARES, A. J. Experimental investigation of the effect orifice shape and fluid pressure has on high aspect ratio cross-sectional jet behavior. Journal of Hazardous Materials, A.89, p. 1-27, 2001.

Como citar:

GODOY, C. M. de; FERREIRA, T. D.; VIANNA, S. S. V.; "O EFEITO DA GEOMETRIA DO VAZAMENTO NA NUVEM DE GÁS INFLAMÁVEL: UMA ANÁLISE SOB A ÓTICA DA SEGURANÇA DO PROCESSO", p-12241-12248. In: Anais do XX Congresso Brasileiro de Engenharia Química - COBEQ 2014 [= Blucher Chemical Engineering Proceedings, v.1, n.2]. São Paulo: Blucher, 2015.
ISSN 23591757, DOI 10.5151/chemeng-cobeq2014-1269-20159-150917