天然气输气站场高处作业跌落事故事件树分析

高处作业作为天然气输气站场主要危险作业之一,长期以来一直影响着天然气管道运输的安全生产。文章在对国家管网西部管道公司天然气输气站场高处作业跌落事故进行安全评价分析的基础上,了解了管道运营维检修中存在的主要安全问题,并针对跌落事件利用事故树进行了分析。这厘清了管道运输生产系统中的薄弱环节,为天然气管道的安全管理提供科学的决策依据,更好地预防伤亡事故的发生。

湿天然气管输瞬变流模型及数值模拟技术研究

湿天然气混输技术的应用可减少海洋、沙漠、戈壁、滩海等条件恶劣的凝析气田的操作人员和降低开采费用。在实际运行中,湿天然气在输送管道中的流动总是处于慢瞬变状态。从流体力学的基本规律出发,建立了描述湿天然气管道输送的瞬变流数学模型方程,并对模型方程作了简化处理,设计了具体的计箕思路。根据输送边界条件,给出了动态模型方程的数值计算方法、管道离散格式、参数存储方法和差分方程。模拟计算了管道储气和供气过程中沿线各点的压力、气液相流速和管内持液率随时间的变化规律。

含氢能气网掺混输运的综合能源系统优化研究

电转气技术的发展缓解了弃风弃光问题,提高了电网和天然气管网的耦合性。在保证安全的前提下,将制得的氢气掺混进入天然气管网进行远距离运输,使天然气管网成为可再生能源的搬运工,能充分缓解能源的时空供需矛盾,提高能源利用率和系统经济性。文中建立了掺氢电-气综合能源系统经济性分析模型,针对华中地区某电-气综合能源系统分析了不同掺氢比下的系统经济性,并与不同储氢容量的本地储氢系统进行了对比。结果表明气网掺氢和本地储氢均能提高系统的经济性,且气网掺氢收益优于本地储氢。但掺氢会导致电网侧的成本和气网侧的收益同时上升,实际运行中须综合考虑燃气定价策略与系统气网结构选择最大掺氢比,从而使系统经济性达到最优。

LNG耐超低温柔性管道研究进展综述——工业应用与结构设计分析

LNG (液化天然气)耐超低温柔性管道是开采、运输、存储LNG过程中的关键装备之一,被誉为是LNG外输系统的“血管”.近年来,随着LNG的开发逐渐由近海走向深远海,耐超低温柔性管道作为LNG外输系统中的核心输运装备迎来了更加广阔的发展前景,同时也面临着由更加严苛的海洋环境带来的结构失效的挑战.本文针对LNG耐超低温柔性管道的工程应用背景、结构设计、内流分析等方面进行了调研与综述,总结了LNG耐超低温柔性管道上述各项技术的研究进展.分析了LNG耐超低温柔性管道的波纹管状结构、螺旋缠绕结构和高分子材料的柔顺性结构特征的力学机理,总结了实现柔顺性结构的方法,梳理了LNG耐超低温柔性管道管内流体计算分析的规律,并对LNG耐超低温柔性管道相关技术的未来研究热点提出了展望.我国在LNG耐超低温柔性管道相关技术的研究工作中起步相对较晚,突破LNG耐超低温柔性管道的结构设计分析与工业应用中的关键力学问题,实现LNG耐超低温柔性管道的国产化研制,对于实现我国深远海天然气资源开发的“卡脖子”技术的自主可控,助力“碳达峰”国家战略目标的实现具有重要意义.

Research on Energy Efficiency Design Index for Sea-going LNG Carriers

This paper describes the characteristics of liquefied natural gas （LNG） carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters fuel substitution rate and recovery of boil of gas （BOG） volume to energy efficiency design index （EEDI） formula are added, and EEDI formula of LNG carriers is established based on ship EEDI formula. Then, based on steam turbine propulsion device of LNG carriers, mathematical models of LNG carriers＇ reference line value are established in this paper. By verification, the EEDI formula of LNG carriers described in this paper can provide a reference for LNG carrier EEDI calculation and green shipbuilding.

Distribution and Chain Pattern of Liquefied Natural Gas Industry in China

The production and consumption of natural gas in China has been developing rapidly in recent years.It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years,and the gas consumption in the primary energy will increase from 0.3% to 10% or more by 2020.However,since the supply of natural gas cannot satisfy the requirements,China has begun to build liquefied natural gas(LNG)terminals in the coastal regions such as Guangdong and Fujian,and solve this problem by importing LNG from foreign countries.LNG needs to be transported by LNG ships from abroad.With the rapid growth of global gas production,the volume of LNG trade also increases,and the interregional production increased from 0.3% in 1970 to 26.2% in 2004.So,we need LNG ships more than before.This article puts forward the distribution of LNG ships and the speculation of the future of LNG transportation based on the studies on foreign LNG production,the LNG trade,the building of LNG ships,the LNG transportation,the chain model of LNG distribution,etc.

Some Insights in Novel Risk Modeling of Liquefied Natural Gas Carrier Maintenance Operations

This study discusses the analysis of various modeling approaches such as genetic algorithms, fuzzy logic and evidential reasoning, and maintenance techniques applicable to the liquefied natural gas （LNG） carrier operations in the maritime environment. The usefulness of these algorithms in the LNG carrier industry in the areas of risk assessment and maintenance modeling as a standalone or hybrid algorithm are identified. This is evidenced with illustrative case studies.

Review of Gas Transportation and Storage Facilities Construction in 2015

By the end of 2015, total length of China＇s long-distance gas pipelines has exceeded 70,O00km. Onshore stratey, ic import paths have been formed, domestic trunk networks perfected and gas storages construction pace acceh＇rated. The Chinese section of Russia-China East Gas Pipeline was officially commenced, which marked that the northeast import path entered the stage ofconstruction. There are 13 LNG terminals in China. The National Development and Rerorm Commission （NDRC） approved China＇s.first private-owned LNG terminal- the Zhoushan LNG terminal. In the coming.five years, the focus of institutional reform will be the independence of pipelines and networks, the focus of construction will be regional networks and branch pipelines, and joint ventures will be the mainstream for gas pipeline construction and operation.

First ERW Ф610 Steel Tube Production Line Brought on Stream

The first domestic ERWФ610 high-frequency straight-seam steel pipe production line was built in Shanghai Zhongyou TIPO Steel Pipe Co Ltd recently. This steel pipe production line initiated inside China has drawn the attention from many enterprises including PetroChina and CNOOC. It is known that the first batch of products have been transported to the construction site of the West-East Gas Transmission Project.

Fatigue reliability for LNG carrier

The procedure of reliability-based fatigue analysis of liquefied natural gas(LNG) carrier of membrane type under wave loads is presented. The stress responses of the hotspots in regular waves with different wave heading angles and wave lengths are evaluated by global ship finite element method(FEM) . Based on the probabilistic distribution function of hotspots' short-term stress-range using spectral-based analysis,Weibull distribution is adopted and discussed for fitting the long-term probabilistic distribution of stress-range. Based on linear cumulative damage theory,fatigue damage is characterized by an S-N relationship,and limit state function is established. Structural fatigue damage behavior of several typical hotspots of LNG middle ship section is clarified and reliability analysis is performed. It is believed that the presented results and conclusions can be of use in calibration for practical design and initial fatigue safety evaluation for membrane type LNG carrier.

The development status and the prospect of the pipeline robots in the oil and gas storage and transportation industry

In the process of the constant development of the oil and gas storage and transportation technology, the maintenance of the large pipelines is an important task. At present, China vigorously promotes the use of the pipeline robots, for the maintenance of the oil and gas pipelines by the unique characteristics of the robots. In this paper, the author carries out the detailed analysis on the current situation of the development of the pipeline robots in the oil and gas storage and transportation industry, and compares the different applications of the pipeline robots at home and abroad. Starting from the principles of the operation of the robots, the author analyzes the characteristics of the different types of the robots, and combined with the existing conditions of the oil and gas storage and transportation in our country, the author tries to find the most favorable way of the working of the pipeline robots, to continuously improve the development of the oil and gas storage and transportation industry using the robot technologies.

Synthesis of Gas Transport through Nano Composite Ceramic Membrane for Esterification and Volatile Organic Compound Separations

The transport behaviour of carrier gases with inorganic catalytic ceramic membrane used for ethyl lactate production and VOC （volatile organic compound） recovery in the gauge pressure range of 0.10-1.00 bar and temperature range of 333 K was investigated. The gases include Ar （argon）, N2 （nitrogen） and CO2 （carbon dioxide）. The gas kinetic diameter with respect to permenace was found to occur in the order of At 〉 CO2 〉 N2, which was not in agreement with molecular sieving mechanism of transport after the first dip-coating of the support. However, gas flow rate was found to increase with gauge pressure in the order of Ar 〉 CO2 〉 N2, indicating Knudsen mechanism of transport. The porous ceramic support showed a higher flux indicating Knudsen transport. The surface image of the dip-coated porous ceramic membrane was characterised using SEM （scanning electron microscopy） to determine the surface morphology of the porous support at 333 K.

To the Issue of Increasing the Efficiency of Operation of Energy Transmission Systems

This paper presents an overview of the safety performance of the major existing pipeline transmission system in Canada, USA and Europe. The article deals the experience of Georgia in the development of pipeline transport. The information on the distribution of catastrophic failures and incidents per individual cause is given. The role of corrosion in these failures is considered. To ensure efficient and reliable operations of oil and gas pipelines, the new compositions of competitive cost effective protective pipe enamel coatings have been developed.

The challenges facing the oil and gas storage and transportation technology and its developing direction

In recent years, our country is increasingly dependent on the use of the oil resources, and the degree of the oil mining is also continuously upgrading. After the completion of the tasks related to the oil mining in the lands, the technologies for the development of the offshore oil mining are particularly important. Among these problems, after the exploitation, the storage and transportation of the offshore oil and gas is worthy of the discussion of the technical personnel. From the experience of the oil and gas storage and transportation in the long years, in some environmentally degraded areas, there are problems in the efficiency and safety in the long pipeline transportation and the oil and gas mixed transportation, and in the transportation, there are also big shortcomings. In this paper, the author carries on the analysis of the existing questions encountering in our country＇s oil and gas storage and transportation~ and proposes the direction of the researches in the future oil and gas storage and transportation, and the purpose is to better improve the security of Cbina＇s oil and gas storage and transportation and to enhance the efficiency of the use of the oil and gas.

Modeling of coupled deformation,water flow and gas transport in soil slopes subjected to rain infiltration

Rain infiltration into a soil slope leads to propagation of the wetting front, transport of air in pores and deformation of the soils, in which coupled processes among the solid, liquid and gas phases are typically involved. Most previous studies on the unsaturated flow and its influence on slope stability were based on the singlephase water flow model (i.e., the Richards Equation) or the waterair two-phase flow model. The effects of gas transport and soil deformation on the movement of groundwater and the evolution of slope stability were less examined with a coupled solid-water-air model. In this paper, a numerical model was established based on the principles of the continuum mechanics and the averaging approach of the mixture theory and implemented in an FEM code for analysis of the coupled deformation, water flow and gas transport in porous media. The proposed model and the computer code were validated by the Liakopoulos drainage test over a sand column, and the significant effect of the lateral air boundary condition on the draining process of water was discussed. On this basis, the coupled processes of groundwater flow, gas transport and soil deformation in a homogeneous soil slope under a long heavy rainfall were simulated with the proposed three-phase model, and the numerical results revealed the remarkable delaying effects of gas transport and soil deformation on the propagation of the wetting front and the evolution of the slope stability. The results may provide a helpful reference for hazard assessment and control of rainfall-induced landslides.

Nano-Morphology of a Polymer Electrolyte Fuel Cell Catalyst Layer Imaging, Reconstruction and Analysis

The oxygen reduction reaction （ORR） in the cathode catalyst layer （CCL） of polymer electrolyte fuel cells （PEFC） is one of the major causes of performance loss during operation. In addition, the CCL is the most expensive component due to the use of a Pt catalyst. Apart from the ORR itself, the species transport to and from the reactive sites determines the performance of the PEFC. The effective transport properties of the species in the CCL depend on its nanostructure. Therefore a three-dimensional reconstruction of the CCL is required. A series of two-dimensional images was obtained from focused ion beam- scanning electron microscope （FIB-SEM） imaging and a segmentation method for the two-dimensional images has been developed. The pore size distribution （PSD） was calculated for the three-dimensional geometry. The influence of the alignment and the anisotropic pixel size on the PSD has been investigated. Pores were found in the range between 5 nm and 205 nm. Evaluation of the Knudsen number showed that gas transport in the CCL is governed by the transition flow regime. The liquid water transport can be described within continuum hydrodynamics by including suitable slip flow boundary conditions.