CNG release from pressurized vessel through pressure relief safety device: isentropic flow approach versus CFD model

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00007064%3AK02__%2F18%3AN0000028" target="_blank" >RIV/00007064:K02__/18:N0000028 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.1088/1742-6596/1107/4/042014/pdf" target="_blank" >https://iopscience.iop.org/article/10.1088/1742-6596/1107/4/042014/pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1742-6596/1107/4/042014" target="_blank" >10.1088/1742-6596/1107/4/042014</a>

Jazyk výsledku

angličtina

Název v původním jazyce

CNG release from pressurized vessel through pressure relief safety device: isentropic flow approach versus CFD model

Popis výsledku v původním jazyce

This paper numerically studies flow characteristics of Compressed Natural Gas (CNG) from a fuel tank of a CNG passenger car through a 3 mm orifice of a temperature triggered pressure relief device (TPRD). The outflow velocity and the methane mass flow are of interest for modelling the gas dispersion both in the vicinity of the orifice as well as further from the leak source. It enables assessing the risk connected with possible accumulation of the explosive gas in enclosures or ignition of leaking gas. An engineering approach of isentropic nozzle flow was compared to the results of a 2D CFD simulation over the whole range of the reservoir working pressure 200 bar (full fuel tank). The pressure in the reservoir was assumed constant. CNG was approximated as pure methane. Methane in the reservoir was set at ambient temperature as well as the surrounding air. Both models predict the same trends both in the methane outflow velocity and mass flow through the orifice. Excellent correspondence between both models was found up to reservoir pressure 50 bar. Above this value, isentropic model predicts about 10 % higher outflow velocity, and even smaller difference was found in the predicted methane mass flow. Mass flow prediction of the isentropic model is, however, strongly dependent on the discharge coefficient. For reservoir pressures between 50 to 200 bar, the Mach number predicted by CFD was in the range from 3.5 to 6 which corresponds to a transition region between super and hypersonic flow. Even at such high speed flow, CFD predictions were consistent with the isentropic nozzle flow theory and in general, the correspondence between both models is very satisfactory.

Název v anglickém jazyce

CNG release from pressurized vessel through pressure relief safety device: isentropic flow approach versus CFD model

Popis výsledku anglicky

This paper numerically studies flow characteristics of Compressed Natural Gas (CNG) from a fuel tank of a CNG passenger car through a 3 mm orifice of a temperature triggered pressure relief device (TPRD). The outflow velocity and the methane mass flow are of interest for modelling the gas dispersion both in the vicinity of the orifice as well as further from the leak source. It enables assessing the risk connected with possible accumulation of the explosive gas in enclosures or ignition of leaking gas. An engineering approach of isentropic nozzle flow was compared to the results of a 2D CFD simulation over the whole range of the reservoir working pressure 200 bar (full fuel tank). The pressure in the reservoir was assumed constant. CNG was approximated as pure methane. Methane in the reservoir was set at ambient temperature as well as the surrounding air. Both models predict the same trends both in the methane outflow velocity and mass flow through the orifice. Excellent correspondence between both models was found up to reservoir pressure 50 bar. Above this value, isentropic model predicts about 10 % higher outflow velocity, and even smaller difference was found in the predicted methane mass flow. Mass flow prediction of the isentropic model is, however, strongly dependent on the discharge coefficient. For reservoir pressures between 50 to 200 bar, the Mach number predicted by CFD was in the range from 3.5 to 6 which corresponds to a transition region between super and hypersonic flow. Even at such high speed flow, CFD predictions were consistent with the isentropic nozzle flow theory and in general, the correspondence between both models is very satisfactory.

Druh

J_ost - Ostatní články v recenzovaných periodicích

CEP obor

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OECD FORD obor

20402 - Chemical process engineering

Projekt

<a href="/cs/project/VI20172019077" target="_blank" >VI20172019077: Průběh a důsledky havarijního úniku CNG z osobních automobilů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Physics: Conference Series

ISSN

1742-6588

e-ISSN

1742-6596

Svazek periodika

1107

Číslo periodika v rámci svazku

042014

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

6

Strana od-do

1-6

Kód UT WoS článku

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EID výsledku v databázi Scopus

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