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1. Introduction
Hydrogen is considered as a promising energy carrier in the 21st century and one of its main applications e hydrogen fuel cell vehicle (HFCV) has attracted much attention from governments and enterprises around the world[1,2]. High-pressure hydrogen storage tanks inc luding type 3 tanks (with metal liners) and type 4 tanks (with plastic liners) are widely used in HFCVs [3]. However, due to the flammability and explosibility of hydrogen and the flammable composite laminates of the tanks, there is a high risk of failure of such tanks under accidental fire exposure.

1 引言

氢气被认为是在第二十一世纪一种很有前途的能源载体和它的一个主要应用氢燃料电池车（总量）已经吸引了来自世界各地的[1,2]，政府和企业的关注。高压储氢容器有限公司泸定3型坦克（金属内衬）和4式坦克（塑料衬垫）广泛用于HFCVs [ 3 ]。然而，由于对易燃、易爆、易燃的氢气复合材料层合板的坦克，有很高的意外火灾暴露在这种坦克失败的风险。

HFCV fire tests implemented by Japan Automobile Research Institute (JARI) and US automobile manufacturers showed that about 40% vehicle fire tests resulted in onboard storage tanks experiencing localized fire[4]. Although local-ized fire could turn into engulfing fire, the localized flame was able to degrade the tank wall locally and even cause the tank to burst. Furthermore, pressure relief device (PRD) could not respond in time to protect the tank in the localized fire condition due to the lack of adequate heat exposure. In-service failure of the tanks used in compressed natural gas vehicles during the past decade also indicated that the most failure was caused by localized fire [5,6].

高频电容-电压特性的防火测试的日本汽车研究所实现的（杰瑞）和美国汽车制造商表明约40%车辆火灾试验导致在船上储罐发生局部火灾[ 4 ]。尽管地方化火能变成火吞噬，本地化的火焰能够降低罐壁局部甚至引起储罐破裂。此外，泄压装置（PRD）不能及时响应保护坦克在局部火灾条件下由于缺乏足够的热暴露。在压缩天然气汽车使用坦克服务失误在过去的十年中也表明，大多数故障是由局部火灾[ 5,6 ]造成的。

The existing draft standards [7 e10] only require bonfire test to demonstrate that PRD can activate and tank will not rupture in engulfing fire. However, bonfire test is not sufficient to evaluate the tank’s susceptibility to localized fire. Thus, a localized fire test method is being developed in latest draft standards such as HFCV-GTR[11] and ISO/DIS 15869 [12] . This test method is based on the information derived from actual vehicle fire tests and preliminary work done by Transport Canada and the National Highway Traffic Safety Administra-tion (NHTSA) in the US [4]. So far, a few investigations have been conducted on this issue. A localized heat impingement experiment for a type 3 tank was carried out by Powertech labs [13] . Hu et al. [14] studied thermal damage of the composite tank subjected to localized flame impingement based on a 2D axisymmetric finite element model. Ruban et al.[15] carried out the localized fire exposure burst test and showed that the tank burst after 5 min 20 s of fire exposure. Some localized fire protection systems were assessed by NHTSA, and the conclusion was that protection effects were excellent but the cost and added weight were never ignored [16] . However, there have been few studies on the heat transfer characteristics of hydrogen composite tanks subjected to localized fire.

In this paper, a three-dimensional computational fluid dynamics (CFD) model is developed to investigate the heat
transfer characteristics of 70 MPa hydrogen composite tanks experiencing localized fire. The effects of di本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。