【摘要】 为提升氢能重型卡车在火灾工况下的安全性，本文针对立式放置的70 MPaⅣ型储氢气瓶开展了火烧条件下的传热特性数值仿真．建立了基于CFD的三维耦合传热模型，并在验证基础上对气瓶在火烧条件下的温度与压力演化规律进行仿真分析，系统探讨了放置方式、气瓶结构、充装介质及初始充装压力等因素的影响．结果表明：在相同火烧条件下，立式放置储氢气瓶因形成稳定的垂直自然对流，其温度和压力增长率分别较卧式高0.6%和0.5%，显著增加了其在长时间火烧下的失效风险；Ⅲ型气瓶内部介质的温度和压力增长率均高于Ⅳ型气瓶；充装氢气相较空气仅引起气瓶内温度升高1.75 K、压力升高0.09 MPa，影响较小；初始充装压力越低，气瓶内介质的温度增长幅度越大，压力增长幅度越小．研究结果可为储氢气瓶的火灾安全评估与结构优化设计提供理论支撑．更多还原

【Abstract】 This study conducted numerical simulations of heat transfer characteristics of vertically placed 70 MPa Type Ⅳ hydrogen storage cylinders under fire exposure to enhance hydrogen-powered heavy-duty truck fire safety. A three-dimensional coupled heat transfer model was established using CFD. After validation,the model was used to simulate and analyze cylinder temperature and pressure evolution under fire conditions. The effects of placement,cylinder structure,filling medium,and initial filling pressure were examined systematically. Results show that vertically placed cylinders develop stable vertical natural convection,exhibiting 0.6% higher temperature growth rate and 0.5% higher pressure growth rate than horizontal cylinders,thus significantly increasing their failure risk during prolonged fires. Type Ⅲ cylinders show higher temperature and pressure growth rates than Type Ⅳ cylinders. Filling the cylinder with hydrogen only causes a temperature rise of 1.75 K and a pressure increase of 0.09 MPa compared with filling it with air,indicating a minor impact. Lower initial filling pressure leads to greater temperature rise but smaller pressure rise. These findings provide theoretical support for the fire safety assessment and optimization design of hydrogen storage cylinders.更多还原