地下工程流–固耦合试验新技术及其在充填型岩溶管道突水模型试验中的应用

在地质力学模型试验技术的基础上,根据大型交通、水利水电及矿山工程的需要,开展大比尺流–固耦合模型试验技术研究,包括新型流–固耦合相似材料、三维可视化固液耦合试验系统以及多物理场信息监测分析技术。提出了流–固耦合相似材料的配制原则,选择了多种性能耦合较小的调节剂,实现了强度、渗透性、重度等指标的独立调节,大大提高了材料的相似度,保证材料能够在水长期作用下保持稳定的性质,很好地模拟中、低强度的岩体、破碎带及充填物。三维可视化固液耦合试验系统具备了自动化静力加载和数字化水压加载功能,实现了复杂地质条件下有压水体与相似材料的大面积直接作用,为流—固耦合条件下渗流和突涌水过程的模拟提供了可视化的试验场所。光纤技术、电阻元件柔性防水技术和自动化数据采集分析系统,实现了水环境下模型体内部渗压、应变和位移的精确采集和分析。最后,依托湖北省保康至宜昌高速公路尚家湾隧道,开展了充填型岩溶管道失稳突水的大比尺三维模型试验研究,真实再现了工程中的突涌水过程,揭示了充填型岩溶管道突水的灾变特征。流–固耦合试验新技术得到成功应用,为试验的顺利进行提供了技术保证。     

氧透进口过滤器冲破事故的原因分析

针对新钢16000 m3/h制氧机氧透发生的两起进口过滤器损坏的事故,分析了氧透控制系统中存在的隐患及其改进措施,总结了在操作中应该吸取的经验和教训。     

中国实验快堆虹吸破坏装置取钠口结构流体动力学分析

中国实验快堆在一回路钠净化系统中设置虹吸破坏装置,以非能动方式减少该系统发生堆外管道破裂事故的液态钠泄漏量。本文对该装置中取钠口结构的发泡动力效应进行研究,从流体动力学分析角度证实该装置改进结构取钠口的泄压能力和非能动减少液态钠泄漏量的能力比原结构取钠口的好。     

氨合成塔进出口换热器的制造技术难点

以某项目氨合成塔进出口换热器的制造过程为研究对象,阐明了此类设备的制造技术难点,包括换热管的质量控制、焊接、无损检测、热处理、管束组装等,并提出了对相关技术问题的解决方法和建议。     

大气参数对燃气轮机进气冷却效果的影响

针对燃气轮机进气冷却的效果在不同大气参数下变化很大的问题,对燃气轮机进气冷却装置的热力过程、影响因素、经济效果等方面进行了研究。基于某电厂燃气轮机和燃气-蒸汽联合循环机组的运行数据,利用热平衡仿真软件Gate Cycle对两种发电机组系统进行模块化建模,并增加进气冷却装置,定量分析了两种发电机组进气被冷却后输出功率的增加量(即进气冷却效果)在不同大气参数(温度、相对湿度和压力)下的变化情况。研究结果表明,大气参数的变化,会对燃气轮机进气冷却的效果产生很大影响,两者之间呈现出一定的数值关系。     

我国离心压缩机的发展历程及未来技术发展方向

对我国离心压缩机的发展历程进行了详尽细致的讨论与分析。结合我国离心压缩机的发展历程特点,阐明了我国离心压缩机未来的技术发展方向,这些发展方向主要体现在压缩机核心部件性能的提升和新型离心压缩机的整体开发。     

浅释钻孔灌注桩在施工中的质量控制

结合施工实践,借鉴前人总结的经验,简析了钻孔灌注桩常见的质量事故,如塌孔、孔位偏移、斜孔、掉钻卡钻、卡管、导管进水、断桩等施工质量通病,并提出防治措施及处理方法,以便能够提高施工质量,减少资金浪费,提高社会效益。     

Flow simulation in Electro-Static-Precipitator (ESP) ducts with turning vanes

Flow simulation in inlet ducts along with several turning vanes used in electrostatic precipitator (ESP) are analysed to understand the flow pattern at its exit locations. The geometry of inlet duct has been extracted from the Plant Design Manufacturing System (PDMS) and refined with turning vanes placed at several locations. The domain of duct geometry around turning vanes are decomposed with several volumes and filled with hexahedral elements with the help of stat-of-art mesh generator - Hypermesh. The resulting computational grid has been used in TASCflow solver to predict its flow pattern in the duct. Simulation for the specified conditions predicts uneven flow distribution in the ESP inlet duct. Due to large flow recirculation and turbulent losses in the duct, non-uniform averaged mass flow rates are noticed at duct exit locations. Simulation results suggest that the improvement of flow distribution in the duct through optimization can be tried by placing more turning/splitter vanes in the inlet duct. In order to ensure that the results obtained from TASCflow are meaningful and in right direction, in the absence of measurement data, simulation was benchmarked with other industry standard commercial flow solvers. The observations made from these popular solvers confirm the findings obtained using the TASCflow solver. The analysis with multiple solvers indicates that Fluent provides quick results, while better visualization can be made using CFX solver. The Star-CD solver, which captures the turbulent losses accurately takes more time for convergence provides alternatives.     

Optimized centre-feed clarifier design for the Tai Po Sewage Treatment Works,Hong Kong

Stability of sludge blanket is a critical factor controlling the performance of clarifiers. A three-dimensional computational fluid dynamics (CFD) model was applied to optimize the clarifier design at the Tai Po Sewage Treatment Works, Hong Kong. Validated by field data, the CFD model evaluated the key clarifier design elements including side-water depth, centre-feed inlet, flocculation well and returned activated sludge (RAS) flow. Based on field observations and modelling results, the new design aims at eliminating the strong turbulence typical of centre-feed inlets in the clarifier, thus creating a better flocculation environment, and reducing disturbance to the sludge blanket. The modelling results also demonstrated a marked improvement in clarifier performance after the increase in clarifier depth and hence sludge storage capacity. The increased storage capacity reduces the risk of high sludge blanket levels upsetting the clarified effluent quality under high flow or solids loading conditions.     

天荒坪电站上水库进出水口截水墙帷幕补强灌浆试验

天荒坪电站上水库采用全库盆沥青混凝土防渗,仅进出水口位置未设置.为防止库水下渗到沥青混凝土库盆的下卧层,设置了截水墙和防渗帷幕,该帷幕长期处于动水压力下,性能削弱较严重,需要补强.为了保证帷幕补强的耐久性,进行了试验,对灌浆的参数和材料进行比选,并用于最终补强施工.