海底摄像系统在中国大洋资源调查中的应用

海底摄像系统是中国大洋资源调查中重要的调查手段,简要介绍了海底摄像系统的基本组成以及其作业方式,并对其在多金属结核资源和富钴结壳资源调查中的应用进行了简单介绍。     

多波束系统在海缆运维中的应用

琼州海峡海缆路由区域地形地貌复杂,对海底电缆综合检测完全依靠外单位进行。目前,国内主流的多波束系统适用于海口分局对海底电缆的测量,现对其实际应用情况进行分析。     

青岛奥帆赛竞赛海域扫测工程的实施与分析

为掌握青岛奥帆基地重点海域海底水深数据、地形地貌及障碍物分布特征,保障奥运会和残奥会的顺利进行,本文采用多波束测深系统对该区海域进行了全覆盖、高效率的海底地形扫测,经过高精度的数据处理,编绘得到海底地形地貌图,并发现了可疑沉船、暗堤等海底障碍物的分布,保障了奥帆赛事的顺利进行。     

基于ADAMS的复合轮式海底车动力学建模与仿真

针对深海富钴结壳和热液硫化调查区复杂多变的底质环境特征,设计了一种具有高越障性能的复合轮式海底车.利用ADAMS软件建立海底车的三维仿真模型,对其垂直越障过程进行动力学仿真分析,获得了海底车关键部件和整车的动力学特性曲线,为海底车路径规划和运动控制系统提供了理论依据.     

机械完整性技术在海底管道事故分析中的应用研究

相对陆地管道,海底管道运行的内外部环境不易勘察与取证,给事故定性带来很大难度,且由于难于识别致因要素,维抢修后隐患难以根治.文中总结了海底管道特点,结合管道完整性管理要求,建立了海底管道完整性管理分析模型,并对一起实际发生的海管泄漏事故进行了分析,取得了满意的结果.对完整性技术在海底管道事故调查中应用进行了总结和展望.     

CCD摄像机全自动调光系统

在CCD摄像系统中,利用电子快门和可变光阑有机结合,在单片机控制下实现全自动调光,不仅扩大了调光的动态范围,而且可有效地控制对运动目标摄像时产生的像移,其最大像移控制在0.0024mm.这些方法应用到使用空间受到限制的小型电视摄像系统中具有现实意义.     

VTS系统在海底电缆保护中的应用研究

海底电缆运行与维护过程中面临的外力破坏风险主要来源于海洋渔业、航运和海洋工程船,故采用先进技术全面监控海底电缆上方船舶航行情况,以有效保护海底电缆的安全显得非常必要。鉴于此,对VTS系统在海底电缆保护中的应用情况进行分析和总结。     

深海海底钻机收放系统动力学随机数值仿真方法研究

提出了一种随机不规则波浪激励下的收放系统动力学随机数值仿真方法。该方法以随机不规则波浪为输入,应用雨流计数法分析收放系统动态特性响应随机分布特征,获取不同水深和海况条件下收放系统动态响应统计规律。以深海海底钻机收放系统为例,对随机不规则波浪激励引起的母船摇荡-脐带缆-深海海底钻机摇荡进行分析,建立了计入海水阻尼的深海海底钻机收放系统动力学模型。然后,以随机不规则波浪的有义波高为特征值,产生随机不规则波浪激励,应用收放系统动力学模型分析计算系统动态随机响应,应用雨流计数法分析收放系统动态响应特性随机分布特征,并对不同水深和海况条件下的钻机摆动状况、升沉运动以及脐带缆张力等动态特性进行随机数值仿真分析与讨论。所提出的方法为随机不规则波浪激励下,海洋装备收放系统动态特性分析提供了新途径。     

基于普通摄像机成像系统测量的误差分析

在人机工程学及人体运动信息检测系统的研究中,较多地应用了基于普通摄像机的三维摄像测试分析系统。由于此系统基本构成原理较复杂,公式推导及实验过程中误差来源较多,所以对此进行了分析,并对减少各种误差的方法进行了初步探讨。     

二自由度管道机器人摄像云台系统设计

介绍摄像云台系统在管道机器人上应用的状况,提出了一种二自由度摄像云台系统,详细阐述了该系统的软件和硬件设计。本设计选用89C51作为主控芯片,CCD图像传感器作为图像采集装置,直流减速电机作为执行机构,使用同步带轮和电机轴直接输出的方式代替一般的齿轮传动,硬件电路实现对云台的控制、检测和限位,各关节位置加入密封设置。结果表明,摄像云台系统具有结构可靠、体积小、拍摄角度广、操作控制简单可靠、速度可调、防护等级高等优点。     

Online monitoring method of hydrate agglomeration in natural gas pipelines based on acoustic active excitation

Natural gas hydrate, which forms and agglomerates under the condition of low temperature and high pressure, can easily affect production or even lead to serious accidents. In order to prevent hydrate agglomeration in a pipeline, the industries generally add seriously excess inhibitor with experience, which causes serious environmental pollution and huge costs. However, due to the uncontrollable production and environmental conditions, hydrate plugging in a pipeline still occurs. According to the issues above, the method, for hydrate agglomeration online monitoring in a natural gas pipeline based on acoustic active excitation, has been presented in this paper. The method is to monitor and locate the hydrate agglomeration in a pipeline in order to take measures in time. Both the modeling and the experimental results show that the method can monitor and locate the hydrate agglomeration online at different locations with good accuracy.     

Study on gas hydrates for the solid transportation of natural gas

Natural gas hydrate typically contains 85 wt.% water and 15 wt.% natural gas, and commonly belongs to cubic structure I and II. When referred to standard conditions, 1 m³ solid hydrate contains up to 200 m³ of natural gas depending on pressure and temperature. Such the large volume of natural gas hydrate can be utilized to store and transport a large quantity of natural gas in a stable condition. In the present investigation, experiments were carried out for the formation of natural gas hydrate governed by pressure, temperature, gas compositions, etc. The results show that the equilibrium pressure of structure II is approximately 65% lower and the solubility is approximately 3 times higher than structure I. It is also found that for the sub-cooling of structure I and II of more than 9 and 11 K respectively, the hydrates are rapidly being formed. It is noted that utilizing nozzles for spraying water in the form of droplets into the natural gas dramatically reduces the hydrate formation time and increases its solubility at the same time.     

Development of a high pressure automated lag time apparatus for experimental studies and statistical analyses of nucleation and growth of gas hydrates

Nucleation in a supercooled or a supersaturated medium is a stochastic event, and hence statistical analyses are required for the understanding and prediction of such events. The development of reliable statistical methods for quantifying nucleation probability is highly desirable for applications where control of nucleation is required. The nucleation of gas hydrates in supercooled conditions is one such application. We describe the design and development of a high pressure automated lag time apparatus (HP-ALTA) for the statistical study of gas hydrate nucleation and growth at elevated gas pressures. The apparatus allows a small volume (≈150 μl) of water to be cooled at a controlled rate in a pressurized gas atmosphere, and the temperature of gas hydrate nucleation, T(f), to be detected. The instrument then raises the sample temperature under controlled conditions to facilitate dissociation of the gas hydrate before repeating the cooling-nucleation cycle again. This process of forming and dissociating gas hydrates can be automatically repeated for a statistically significant (>100) number of nucleation events. The HP-ALTA can be operated in two modes, one for the detection of hydrate in the bulk of the sample, under a stirring action, and the other for the detection of the formation of hydrate films across the water-gas interface of a quiescent sample. The technique can be applied to the study of several parameters, such as gas pressure, cooling rate and gas composition, on the gas hydrate nucleation probability distribution for supercooled water samples.     

改善R134a气体水合物生成措施的探讨

以成核动力学和泡态沸腾为理论基础，分析了R134a气体水合物生成的实验研究结果，探讨了改善其生成的措施。     

A high-pressure cell for kinetic studies on gas hydrates by powder x-ray diffraction

A new high-pressure-low-temperature cell was developed for in situ observations of gas hydrates by powder x-ray diffraction. The experimental setup allows investigating hydrate formation and dissociation as well as transformation processes between different hydrate crystal structures as a function of pressure, temperature, and feed gas composition. Due to a continuous gas flow, the composition of the gas phase is kept constant during the whole experiment. This is crucial for the formation of mixed hydrates formed from feed gas mixtures that contain one or more components in low concentrations. The pressure cell can be used in a pressure range between 0.1 and 4.0 MPa and a temperature range between 248 and 298 K. First results of time-resolved measurements of a mixed structure II CH(4) + iso-C(4)H(10) hydrate and a structure I CO(2) hydrate are presented.     

CO_2水合物浆固相分数的计算及其对流动特性的影响

CO2水合物浆做为一种新型的两相载冷剂,具有较高的相变潜热和合适的相变温度,在蓄冷领域有良好的发展前景。而明确水合物浆的物性参数及其计算方法是对其进行高效安全应用的基础。本文对CO2在水合物存在下的溶解度特性及其流变特性等计算方法进行了分析探讨,建立了CO2水合物浆固相分数的理论计算模型,并试验研究了不同固相分数下CO2水合物浆的流动特性,结果发现流速0.6～0.65m/s为流动特性的转折区域。在低流速时,CO2水合物浆的流变指数小于1,且随着固相分数的增大而减小。研究结果可为CO2水合物浆蓄冷技术的发展应用提供理论指导。     

Aggregation behavior analysis of hydrate particles in the bend pipe based on the population balance model

Journal of Mechanical Science and Technology - The hydrate particle aggregation is crucial for the flow safety of oil and gas pipelines. In this paper, coupled with the Eulerian-Eulerian model,...     

Fiber optic sensing technology for detecting gas hydrate formation and decomposition

A fiber optic-based distributed sensing system (DSS) has been integrated with a large volume (72 l) pressure vessel providing high spatial resolution, time-resolved, 3D measurement of hybrid temperature-strain (TS) values within experimental sediment-gas hydrate systems. Areas of gas hydrate formation (exothermic) and decomposition (endothermic) can be characterized through this proxy by time series analysis of discrete data points collected along the length of optical fibers placed within a sediment system. Data are visualized as an animation of TS values along the length of each fiber over time. Experiments conducted in the Seafloor Process Simulator at Oak Ridge National Laboratory clearly indicate hydrate formation and dissociation events at expected pressure-temperature conditions given the thermodynamics of the CH(4)-H(2)O system. The high spatial resolution achieved with fiber optic technology makes the DSS a useful tool for visualizing time-resolved formation and dissociation of gas hydrates in large-scale sediment experiments.     

非常规油气实验室建设的必要性

非常规油气资源丰富,开发潜力巨大,近几年随着常规油气资源探明储量的不断下降,全球对非常规油气资源给予了更多的关注,许多国家对非常规油气资源的勘探开发进行了深入的研究。我国在该领域也做了大量研究工作,但总体水平与国外相比还是相对落后,其主要原因是基础实验设备和解决重大勘探开发关键技术的标志性仪器缺乏,使得我国非常规油气勘探开发研究的步伐比较缓慢。非常规油气实验室的建设将会大大促进我国非常规油气勘探开发研究,使我国在全球非常规油气勘探开发理论技术方面占有一席之地,并且使非常规油气业务真正成为我国油气资源生产的重要补充。     

Novel gas-tight multi-sampler for discrete deep-sea water

The issues of how to quickly collect seawater samples and of how to make sure that those samples truly reflect the in-situ information on gas composition and concentration have therefore become a hot but difficult topic in the field of ocean technology.Most conventional seawater samplers only focus on collecting seawater itself,but take little consideration on gas preservation.A set of new oceanographic tools are presented for ocean resource exploration such as hydrothermal sulfide and gas hydrate,and for investigations on the processes and mechanisms of marine physical,chemical and biological evolutions.A gas-tight deep-sea water sampling system(GTWSS) is designed for the collection of deep-sea geochemical samples.This set of tools mainly consists of a conductivity temperature depth profiler(CTD),release devices and gas-tight deep-sea water samplers(GTWS).The GTWS is able to hold the gases in deep-sea water samples tightly,providing in-situ information on gas contents in the seawater samples and can be deployed on a routine wire-deployed CTD sampler for multi-layer discrete sampling of gas-tight seawater.Sea trials are performed successfully in 2008 and 2009,on a research vessel named HaiYang Si Hao in South China Sea,with the deepest trial depth 3 930 m.GTWSS is capable of quickly sampling 12 discrete gas-tight seawater samples(8.3 L per sample) during its single deployment.The head space method is employed to separate the gases from the seawater samples immediately after recovery of the seawater samples on the vessel.Field geochemical analysis is carried out by gaseous hydrocarbon sensors and an infrared gas analyzer.Results show that the concentrations of CH4 and CO2 in the seawater sampled by GTWSS are higher than those sampled by general non-gas-tight water samplers,thus confirming the gas tightness of GTWSS.Seawater samples can be collected quickly by using GTWSS,and GTWSS can keep the samples’ integrity quite well.