大型立式低温LNG储罐的结构设计和强度研究

大型立式低温液化天然气LNG储罐是储存、运输LNG的关键设施,其占地面积较小、成本较低,便于管理。基于此,有必要对大型立式低温LNG储罐的结构设计和强度进行研究,旨在提高大型立式低温LNG储罐的性能,提高LNG的运输效率。主要对大型立式低温LNG储罐结构、设计要求、强度分析进行了研究。     

大型低温卧式LNG储罐的设计、制造

随着国内外对低温卧式储罐的大型化要求,开发和完善低温卧式储罐设计和制造技术已势在必行。LNG作为一种新兴的清洁能源,随着其液化技术的不断进步,液化成本与之前相比大大降低,提高了LNG与其它能源的竞争力,使其应用日益广泛。文章着重介绍了大型低温卧式LNG储罐的基础知识,包括设计、制做、运输等。     

大型低温卧式LNG储罐的设计、制造

随着国内外对低温卧式储罐的大型化要求,开发和完善低温卧式储罐设计和制造技术已势在必行。LNG作为一种新兴的清洁能源,随着其液化技术的不断进步,液化成本与之前相比大大降低,提高了LNG与其它能源的竞争力,使其应用日益广泛。文章着重介绍了大型低温卧式LNG储罐的基础知识,包括设计、制做、运输等。     

LNG低温储罐冷量损失在设计中的计算方法

介绍大型液化天然气(LNG)低温储罐冷量损失(蒸发率)的计算方法、LNG储罐设计过程中保温系统的设计和保温性能的测试。     

化工厂大型LNG低温储罐土建施工技术

大型LNG低温储罐土建施工环节,就是对大型储罐进行搭建、浇筑作业,包括:施工前准备、混凝土分层、钢筋绑扎、模板搭建(底模板与侧模板)、混凝土浇筑、表面装饰与成品养护。由于大型LNG低温储罐施工过程较为复杂,需要严格遵循每一工序的操作要求、规范施工作业技术,保证混凝土浇筑成品质量良好,避免出现裂缝、漏筋等情况,保证土建施工质量。结合大型LNG低温储罐工程案例,从多个工序环节入手,对大型LNG低温储罐土建施工技术进行深入探究,提出大型LNG低温储罐土建施工成品裂缝及其预防方法。     

30000 m~3单容双壁LNG储罐施工技术

LNG储罐作为LNG的陆上储存设备,属常压、低温大型储罐,通常为平底、双壁圆柱形,主要分为单容罐、双容罐及全容罐。单容式储罐投资相对较低、施工周期短,但容易泄漏,其制作、安装技术显得尤为重要。现以湖北某5×10~6m~3/d LNG工厂国产化示范工程30 000 m~3LNG储罐为例,从储罐的结构、安装、焊接、保冷、水压/气压试验等方面对其施工技术进行阐述。     

LNG储罐蒸发规律在储罐设计中的应用

大型LNG低温储罐的设计一直是国内低温行业致力于研发的课题。为了更好的掌握设计LNG储罐的理论依据和设计精髓,本文根据以往的研究成果,进一步讨论了LNG储罐的蒸发规律,确定了储罐设计过程中考虑蒸发与LNG储罐直径、初始充装率、环境温度和保温材料性能有关。其中前两个因素要着重考虑,后两个因素作为设计输入。以3万m3LNG储罐为例,根据确定的蒸发率主要影响因素,计算了储罐工艺设计的基本尺寸参数为最佳直径在40～50m间。     

大型LNG储罐预冷动态模拟

大型常压LNG储罐在接收站中占有很高的投资份额,是接收站关键的储存容器,在启用时对调试技术的要求较高,其中,储罐的冷却是最重要的预备环节。基于气液两相容积节点原理,建立喷淋LNG蒸发计算模型,搭建大型LNG储罐预冷过程动态仿真平台,以160000 m³大型LNG地上全容储罐为例,计算其在预冷过程中所需要的时间以及预冷所用LNG总量,得到了预冷过程中储罐压力、BOG产生量以及储罐内部温度的动态变化,为设计优化液化天然气储罐预冷策略提供了理论依据。     

LNG低温储罐区平面布置设计方案的探讨

近年来我国LNG大型低温储罐正在大范围兴建,LNG储罐区的安全性和可靠性也受到广泛的关注。作者结合工程设计实例,根据《石油天然气工程设计防火规范》(GB 50183)就LNG低温储罐区的平面布置设计方案进行探讨。文章简述了规范的相关要求,重点对LNG低温储罐区围堰的设计及其周边安全防护距离(防火间距、热辐射隔热距离、蒸汽云扩散隔离距离)的确定进行总结。     

LNG低温储罐内罐壁板焊接质量控制分析

LNG低温储罐内罐壁板是LNG储罐必不可少的组成部分,在储罐安全运行中发挥着至关重要的作用。本文以某大型LNG低温储罐内罐壁板为研究对象,通过对焊接过程、焊接难点、质量控制及优化措施的分析,提出一系列提高LNG低温储罐内罐壁板焊接质量的方法和措施,为LNG储罐建设质量提供工程技术支撑和焊接质量控制可靠性分析。     

Aluminum,Arsenic, Beryllium,Cadmium, Chromium,Cobalt, Copper,Iron, Lead,Mercury, Molybdenum,Nickel, Platinum,Thallium, Titanium,Vanadium, and Zinc: Molecular Aspects in Experimental Liver Injury

Experimental liver injury with hepatocelluar necrosis and abnormal liver tests is caused by exposure to heavy metals (HMs) like aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, mercury, molybdenum, nickel, platinum, thallium, titanium, vanadium, and zinc. As pollutants, HMs disturb the ecosystem, and as these substances are toxic, they may affect the health of humans and animals. HMs are not biodegradable and may be deposited preferentially in the liver. The use of animal models can help identify molecular and mechanistic steps leading to the injury. HMs commonly initiate hepatocellular overproduction of ROS (reactive oxygen species) due to oxidative stress, resulting in covalent binding of radicals to macromolecular proteins or lipids existing in membranes of subcellular organelles. Liver injury is facilitated by iron via the Fenton reaction, providing ROS, and is triggered if protective antioxidant systems are exhausted. Ferroptosis syn pyroptosis was recently introduced as mechanistic concept in explanations of nickel (Ni) liver injury. NiCl₂ causes increased iron deposition in the liver, upregulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, downregulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), nuclear receptor coactivator 4 (NCOA4) protein, and mRNA expression levels. Nickel may cause hepatic injury through mitochondrial damage and ferroptosis, defined as mechanism of iron-dependent cell death, similar to glutamate-induced excitotoxicity but likely distinct from apoptosis, necrosis, and autophagy. Under discussion were additional mechanistic concepts of hepatocellular uptake and biliary excretion of mercury in exposed animals. For instance, the organic anion transporter 3 (Oat3) and the multidrug resistance-associated protein 2 (Mrp2) were involved in the hepatic handling of mercury. Mercury treatment modified the expression of Mrp2 and Oat3 as assessed by immunoblotting, partially explaining its impaired biliary excretion. Concomitantly, a decrease in Oat3 abundance in the hepatocyte plasma membranes was observed that limits the hepatic uptake of mercury ions. Most importantly and shown for the first time in liver injury caused by HMs, titanium changed the diversity of gut microbiota and modified their metabolic functions, leading to increased generation of lipopolysaccharides (LPS). As endotoxins, LPS may trigger and perpetuate the liver injury at the level of gut-liver. In sum, mechanistic and molecular steps of experimental liver injury due to HM administration are complex, with ROS as the key promotional compound. However, additional concepts such as iron used in the Fenton reaction, ferroptosis, modification of transporter systems, and endotoxins derived from diversity of intestinal bacteria at the gut-liver level merit further consideration.     

THERMOPLASTIC,FLEXIBLE, AND RECYCLABLE COMPOSITES,DESIGN, PREPARATION,AND CHARACTERIZATION

Glass fiber reinforced composites based on thermosets are the traditional materials used for many applications due to their good mechanical properties. The non-recyclability of these materials has led to the necessity to develop thermoplastic composites and industrial processes for their manufacture [1]. The present paper deals with the preparation of thermoplastic pre-pregs unidirectionally reinforced with Twarn® and their mechanical characterization.     

DUO-ICP-AES测定精对苯二甲酸中的钴、铬、铁、锰、钼、镍、钛

采用DUO-ICP-AES同时测定精对苯二甲酸中钴、铬、铁、锰、钼、镍、钛,并对仪器的分析线选择、背景校正、入射功率、雾化器压力、辅助气流量、冷却气流量、蠕动泵转速的影响及共存元素的干扰、硝酸铯灰化助剂等因素进行了详细的研究。方法的检测限:钴0.0097 mg/L;铬0.0021 mg/L;铁0.0078 mg/L;锰0.0012 mg/L;钼0.0027 mg/L;镍0.016 mg/L;钛0.0027 mg/L,回收率和精密度分别为93.0%～99.5%和0.37%～3.2%。该方法快速简便,具有良好的精密度和准确度,适用于进出口精对苯二甲酸的日常检验。     

Pd-, Ni-, Fe-, and Co-Catalyzed Cross-Couplings Using Functionalized Zn-, Mg-, Fe-, and In-Organometallics

The development of new methods for preparing polyfunctional organometallics has made a broad range of such reagents available for various transition metal-catalyzed cross-couplings. An overview of the most general preparation methods will be presented. Applications to practical cross-coupling procedures will be covered, emphasizing the functional group compatibility and the reaction scope.