海洋石油平台冷放空系统设计及模拟分析

海洋石油平台冷放空系统的设计影响平台安全、结构重心以及工程费用。冷放空系统的设计需要根据感受点的位置对冷放空臂长度进行精确的模拟计算,以确保平台人员及设备的本质安全。以海上某无人平台为例,利用PHAST及FLARESIM软件进行冷放空系统模拟分析,根据冷放空泄放中产生的热辐射、噪音及气体扩散对平台产生的影响,选取合适的放空臂长度。     

Experimental and numerical analysis of fire scenarios involving two mechanically ventilated compartments connected together with a horizontal vent

This work deals with an experimental and numerical investigation of a fire scenario involving two rooms mechanically ventilated and connected together with a horizontal vent. The objective is to improve the understanding of the physical phenomena and to assess the capability of computational fluid dynamics (CFD) numerical simulations to predict flow field for such a fire scenario. The study is based on a set of large‐scale fire experiments performed in the framework of the OECD PRISME‐2 project in the DIVA multi‐room facility of the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) and of numerical simulations performed with the ISIS CFD code. The fire scenario consists of two rooms, one above the other, mechanically ventilated and connected to each other with a horizontal vent of 1 m². The fire is a heptane pool fire located in the lower room. The analysis focuses on the coupling between the burning rate, the flow at the vent, and the configuration of the mechanical ventilation. Several regimes of combustion are encountered from well‐ventilated steady fire to under‐ventilated unsteady and oscillatory fire. The results show that the burning rate is controlled by both the mechanical ventilation and the downward flow from the vent. The numerical simulations highlight the specific pattern of the oxygen concentration field induced by the downward flow at the vent.     

A comparison study into low leak rate buoyant gas dispersion in a small fuel cell enclosure using plain and louvre vent passive ventilation schemes

Hydrogen, producing electricity in fuel cells, is a versatile energy source, but with risks associated with flammability. Fuel cells use enclosures for protection which need ventilating to remove hydrogen emitted during normal operation or from supply system leaks. Passive ventilation, using buoyancy driven flow is preferred to mechanical systems. Performance depends upon vent design, size, shape, position and number. Vents are usually plain rectangular openings, but environmentally situated enclosures use louvres for protection. The effect of louvres on passive ventilation is not clear and has therefore been examined in this paper. Comparison ‘same opening area’ louvre and plain vent tests were undertaken using a 0.144 m³ enclosure with opposing upper and lower vents and helium leaking from a 4 mm nozzle on the base at rates from 1 to 10 lpm, simulating a hydrogen leak. Louvres increased stratified level helium concentrations by typically in excess of 15%. The empirical data obtained was also used in a validation exercise with a SolidWorks: Flow Simulation CFD model, which provided a good qualitative representation of flow behaviour and close empirical data correlations.     

滚球半径法确定瓦斯抽放泵站放空管合理安置区域

为了确定瓦斯抽放泵站放空管合理安置区域。在滚球半径法推算原理的基础上,利用几何知识,使用AutoCAD绘图软件绘制瓦斯抽放泵站放空管合理安置区域,而非传统方法的若干公式计算。AutoCAD绘图软件作图的方法避免了《GB 50057-2010建筑物防雷设计规范》附录D中传统方法繁琐的计算。确定瓦斯抽放泵站放空管合理安置区域作图法直观、简单、清晰、明了,简化了瓦斯抽放泵站防雷设计工作。为科学合理确定瓦斯抽放泵站放空管位置提供了依据。     

透壁通风管路堤降温效应的室内试验研究

介绍了研究透壁通风管路堤降温效果的室内试验方法,对100cm×60cm×100cm尺寸的不同通风管路堤试样进行了实验研究。结果表明,采用透壁通风管能明显增强路堤的降温效果,而只在负温期间通风的透壁通风管路堤降温效果更为显着,路堤在通风管进风口附近的温度变化幅度以及负温区域的范围都明显大于通风管出风口处,形成了路基温度场沿着风向的不对称分布。     

有压污水输送管道通气井的设置

结合实测透气数据,运用变波速模型对不同点位类型进行了分析,通过计算管道的压力变化研究了有压污水管中的气液两相流。对三个方案进行了分析:①污水管道沿程都不设通气井;②在地形突变处设立通气井;③除地形突变处外,平直管道隔2 km设一个通气井。计算结果表明,除在倒虹管处等地形突变的地方以及平直管段隔2 km距离就应设置通气井外,其余平直管道处可以不设置通气井。     

北京某住宅小区人防地下室通风深化设计

本文通过工程实例,介绍了人防地下室的进、排风系统,以及各种通风方式下阀门、风机的控制方法。给出了进排风口部原理图,以及战时通风的主要计算过程。     

海上平台热采放喷气扩散数值模拟研究

为确保海洋稠油热采平台的安全生产,建立海上平台热采放喷气扩散数学模型,利用ANSYS Fluent软件对蒸汽吞吐热力开采过程中气体的扩散进行模拟计算,量化热采放喷过程对平台的影响,从而指导平台设备设施总体布置。以旅大21⁃2油田为例进行分析,由于放喷后期甲烷含量升高,且放喷气量减小造成扩散速度慢,放喷气容易在蒸汽锅炉等较高的设备间富集造成安全隐患。通过优化放空系统参数和设备布置方案,最大限度降低了热采放喷和冷放空对安全操作的影响,并减小平台面积5.9%。建立的模型考虑了平台主要设备结构、气体组分、风速、湍流脉动等因素的影响,满足工程精度要求,研究结果为热采平台的安全设计提供可靠依据。     

基于ASPEN PLUS的磷酸二铵装置尾气洗涤及余热回收研究

利用脱盐水间接冷凝尾气中的水蒸气以减少白雾的排放和回收尾气的低温位余热,同时使用ASPEN PLUS软件对尾气洗涤塔及余热回收过程进行模拟。结果表明,该软件模拟结果与现场测量参数较为吻合,可用于指导生产,并为装置改造提供依据。