海洋工况下海洋小堆热工水力特性分析

海洋的开发,对核能有很大的需求空间。相较于陆基堆,海洋小堆在堆形的结构设计、设备及系统布置等,有着不同的特征。为适应船舶舱室与海洋环境,本文参照某型模块化小堆的主要设备结构和系统布置,得到一种改进后的海洋一体化小堆设计方案和设计参数。使用添加了海洋工况计算模块的RELAP5软件,对其中一个设计方案,引入海洋工况;通过和船舶设计单位的深度合作,得知其在产品生产设计中重点关注的摇摆及倾斜工况:一般设计角度:22.5°以及极限设计角度:45°等。在强迫循环及RELAP5稳态卡中暂未加入控制模块的情形下,根据模拟结果,观察和分析关键热工水力参数的运行特性。

海洋工况下稳压器自由液面晃荡效应分析及预防措施研究

自由液面晃动问题对海洋浮动平台反应堆系统稳压器的稳定运行及一回路冷却剂系统的压力稳定性有着很大的影响。为了保证稳压器及压力安全系统的稳定运行,对反应堆一回路系统主设备稳压器内自由液面在运行期间的晃荡效应及其潜在影响进行了分析,在此基础上开展对应的预防措施研究,结合稳压器自身结构给出了可行的防晃措施,对海洋工况下的稳压器设计提供了参考。

工信部传达贯彻十八届五中全会精神

近日,工业和信息化部召开干部大会,传达贯彻党的十八届五中全会精神。部党组书记、部长苗圩传达了五中全会和《中共中央关于制定国民经济和社会发展第十三个五年规划的建议》(以下简称《建议》)的主要精神,并代表部党组提出贯彻落实要求。苗圩代表部党组提出五点要求。一是认真抓好全会精神学习宣传,切实把思想和行动统一到中央决策部署上来。

LNG-FSRU再气化模块IFV试验换热器液面晃荡数值模拟研究

为了解海洋工况下液面波动对海工IFV换热器的影响,制作了一台试验用换热器样机,该换热器内部设置了防液面晃荡装置,本文对该试验用换热器的液面晃荡情况进行了数值模拟,模拟结果显示防晃荡装置对液面波动起到了有效的抑制作用,能够满足海洋工况条件的要求。

船用压水堆稳压器水位测量系统研究设计

在海洋摇摆工况下,水位的虚晃会影响稳压器水位测量的精准度,对核电站的安全构成严重的威胁。为了能够精确地测量稳压器水位,论文提出了一种双参考稳压器水位测量系统。经过分析论证,该系统在一定程度上能够提高稳压器水位测量的精确度,确保船用核动力装置的安全运行。

省政府关于化解产能过剩矛盾的实施意见

苏政发[2013]162号各市、县(市、区)人民政府,省各委办厅局,省各直属单位:为深入贯彻落实《国务院关于化解产能严重过剩矛盾的指导意见》(国发[2013]41号)精神,积极有效化解部分行业产能过剩矛盾,实现江苏工业经济有质量、有效益、可持续发展,提出如下实施意见。一、化解部分行业产能过剩矛盾的意义受发展阶段、发展理念和体制机制等多种因素的影响,我国传统制造业产能普遍过剩,特别是钢铁、水泥、电解铝等高消耗、高排放行业尤为突出。我省在钢铁、水泥。

中国装备制造业产值居世界首位 总量突破20万亿元

据悉,2013年我国装备制造业产值规模突破20万亿元,是2008年的2.2倍,年均增长17.5%,占全球装备制造业的比重超过1/3,稳居世界首位。据工业和信息化部副部长苏波介绍,我国多数装备产品产量位居世界第一。2013年发电设备产量1.2亿千瓦,约占全球总量的60%;

Steady State Analysis of Towed Marine Cables

Efficient numerical schemes were presented for the steady state solutions of towed marine cables. For most of towed systems,the steady state problem can be resolved into two-point boundary-value problem,or initial value problem in some special cases where the initial values are available directly.A new technique was proposed and attempted to solve the two-point boundary-value problem rather than the conventional shooting method due to its algorithm complexity and low efficiency.First,the boundary conditions are transformed into a set of nonlinear governing equations about the initial values,then bisection method is employed to solve these nonlinear equations with the aid of 4th order Runge-Kutta method.In common sense,non-uniform (sheared) current is assumed,which varies in magnitude and direction with depth.The schemes are validated through the DE Zoysa's example,then several numerical examples are also presented to illustrate the numerical schemes.

Depression and elevation internal solitary waves in a two-layer fluid and their forces on cylindrical piles

Both large amplitude depression and elevation internal solitary waves （ISWs） were observed on the continental shelf of the northwest South China Sea （SCS） during the Wenchang Intemal Wave Experiment. In this study, we investigate the characteristics of depression and elevation ISWs based on comparisons between observational results and internal wave theories. It is suggested that the large amplitude depression wave is better represented by the extended Korteweg-de Vries （EKdV） theory than by the KdV model, whereas the large amplitude elevation wave is in better agreement with the KdV equation than with the EKdV theory. Wave-induced forces on a supposed small-diameter cylindrical pile by depression and elevation waves are also estimated using the internal wave theory and Morison formula. The wave-induced force by elevation ISWs is rarely reported in the literature. It is found that the force induced by the elevation wave differs significantly fi＇om that by the depression wave, and the elevation wave generally produces greater force on the pile in the lower water column than the depression wave. These results show that ISWs in the study area can present a serious threat to ocean engineering structures, and should not be ignored in the design of oil platforms and ocean operations.

Dynamic Response Analysis of Towed Cable During Deployment/Retrieval

A numerical approach was developed to analyze the transient behavior of towed cable during ac- tively controlled deployment/retrieval (DR).The cable motion is described by the lumped parameter method, its corresponding boundary conditions are presented.In view of its varying length during DR,two auxiliary arguments are introduced to describe its continuous varying length and discrete number of nodes(equations), the length is determined by the pay out(or reel-in) rate,which is then used to determine the node number by a logic relation.For the discrete mathematical model of towed cable,an algorithm was developed to deal with the discrete governing equations.The simulation results indicate that the cable experiences more com- plex motions due to its varying length,and tension fluctuates seriously in the startup and ending stage of deployment/retrieval.The effect of towing ship's motion in waves on cable during deployment/retrieval is also considered via numerical simulation.

Magnetic Detection Method for Seabed Cable in Marine Engineering Surveying

The detection and identification of the seabed cable is becoming an important task in the marine engineering. The features of the magnetic anomaly can be used to detect the existence of the seabed cable. The magnetic field model is presented, and the consistency of the magnetic anomaly distribution between the simulation of the model and the observed data is verified. The comparison shows that the seabed cable can be effectively detected and identified with reasonable method.

Grouting Control for Deep-Water Jacket Skirt Pile

Deep-water jacket skirt pile grouting is a critical step in ocean platform construction. Because of the complexity of the skirt pile structure and grouting pipeline, the calculation of grouting pressure and the control of output pressure are involved. Beginning with the jacket skirt pile grouting construction scheme, grouting pressure is estimated on the basis of engineering fluid mechanics theory and variable frequency control technique. Programmable logic controller is the center of grouting pressure control system, which accomplishes the flow control of cement buffer tank, water buffer tank, additive buffer tank, cement metering tank, water metering tank, additive metering tank, mixer and agitator. Based on PROFIBUS-DP network, the output pressure of the slurry pump is controlled by the inverter. This method has been applied successfully in JZ20-2 Nor. high spot jacket platform construction.

Influence of Reclamation Works on the Marine Environment in a Semi-Enclosed Bay

The flow and seawater exchange rates have been predicted using a two-dimensional numerical model and a Lagrangian method for a semi-enclosed shallow bay where reclaiming and dredging works are scheduled. The wind effect on the flow and material transport has been emphasized, and a thirty-year mean value of wind has been considered in the numerical simulation. As a whole, even after the reclaiming and dredging are conducted, the flow pattern looks similar to the original state. However, velocity variations up to 20% to 100% appear in the vicinity of the construction area. In the case of summcr wind forcing, the seawater exchange rate increases from 71.6% to 82.9% after the reclaiming and dredging, as indicated by a particle-tracking method. On the contrary, in the case of winter wind forcing, thc seawater cxchange rate appears to be 97.2% under natural conditions but decrcases slightly to 93.2% aftcr the rcclaiming and dredging. Thus, the wind forcing plays an important role in controlling the seawater exchangc rates. The seawater cxchange rate is further improved by 15% if the dredging is simultaneously carried out with the reclaiming. This suggests that the dredging can be an effective means to mitigate the variation of flow.

Marine Structures: Future Trends and the Role of Universities

This paper emphasizes some of the challenges and trends associated with the future development of marine structures. Its main focus is on ways to improve the efficiency of energy-consuming ships, and on design challenges related to energy-producing offshore structures. This paper also discusses the analysis tools that are most needed to enable sustainable designs for future ships and offshore structures. The last section of the paper contains thoughts on the role of universities in education, research, and innovation regarding marine structures. It discusses curriculum requirements for maritime-technology education, basic research activities, and international cooperation.

Sanders＇ Mid-long Cylindrical Shell Theory and its Application to Ocean Engineering Structures

The cylindrical shell is one of the main structural parts in ocean engineering structures.These cylinders are mostly of medium length,which means that the radius of the cross section is significantly smaller than the length of the cylindrical shell.From the viewpoint of the shell theory,they belong to the mid-long cylindrical shell category.To solve mechanical problems on this kind of structure,especially a cracked cylindrical shell,analysis based on shell theory is necessary.At present the generally used solving system for the mid-long cylindrical shell is too complicated,difficult to solve,and inapplicable to engineering.This paper introduced the Sanders' mid-long cylindrical shell theory which reduces the difficulty of the solution process,and will be suitable for solving problems with complicated boundary conditions.On this basis,the engineering applications of this theory were discussed in conjunction with the problem of a mid-long cylindrical shell having a circumferential crack.The solution process is simple,and the closed form solution can usually be found.In practical engineering applications,it gives satisfactory precision.

The influence of Fe^(2+) on growth and development of cells enzy-matically isolated from Porphyra yezoensis blades

Fe2+ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe2+ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentra- tions of Fe2+. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1–102.1 μg/L, 10–100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentra- tions, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually.

Nature, Source and Composition of Volcanic Ash in Surficial Sediments Around the Zhongsha Islands

Volcanic detrital sediments are a unique indicator for reconstructing the petrogenetic evolution of submarine volcanic terrains. Volcanic ash in surficial sediments around the Zhongsha Islands includes three kinds of volcanogenic detritus, i.e., brown volcanic glass, colorless volcanic glass and volcanic scoria. The major element characteristics show that bimodal volcanic activity may have taken place in the northern margin of the South China Sea, with brown volcanic glass and colorless volcanic glass repre- senting the mafic end-member and felsic end-member, respectively. Fractional crystallization is the main process for magma evolu- tion. The nature of the volcanic activity implies that the origin of volcanic activity was related to extensional tectonic settings, which is corresponding to an extensional geodynamic setting in the Xisha Trench, and supports the notion, which is based on geophysical data and petrology, that there may exist a mantle plume around the Hainan Island.

The ultimate strength of doubler plate reinforced Y-joints under compression loading

It is common practice in the offshore industry to solve the punching shear problem due to compression by using doubler plate. The finite-element method is a useful tool for studying this problem. The aim of this paper is to study the static strength of doubler plate reinforced Y-joints subjected to compression loading. The finite-element method is adopted in numerical parametric studies. The individual influences of the geometric parameters βand τd （doubler plate to chord wall thickness ratio） and ld/d1（dubler plate length to brace diameter ratio） on the ultimate strength are made clear. The results show the size of plate may have important effects on the strength of reinforced joints. It is found that the ultimate strength of Y-joints reinforced with appropriately proportioned doubler plates can be greatly improved nearly up tothree times to un-reinforced Y-joints.

An investigation of the performance of an electronic in-line pump system for diesel engines

WIT Electronic Fuel System Co.,Ltd.has developed a new fuel injector,the Electronic In-line Pump(EIP) system,designed to meet China's diesel engine emission and fuel economy regulations.It can be used on marine diesel engines and commercial vehicle engines through different EIP systems.A numerical model of the EIP system was built in the AMESim environment for the purpose of creating a design tool for engine application and system optimization.The model was used to predict key injection characteristics under different operating conditions,such as injection pressure,injection rate,and injection duration.To validate these predictions,experimental tests were conducted under the conditions that were modeled.The results were quite encouraging and in agreement with model predictions.Additional experiments were conducted to study the injection characteristics of the EIP system.These results show that injection pressure and injection quantity are insensitive to injection timing variations,this is due to the design of the constant velocity cam profile.Finally,injection quantity and pressure vs.pulse width at different cam speeds are presented,an important injection characteristic for EIP system calibration.

A Study of Oceanic Reverberation Modeling Based on a Nonlinear Low-Dimensional Dynamic System

Acoustic reverberation signals generated by an experimental explosive source are analyzed by nonlinear dynamical methods. Three characteristic parameters, i.e., the correlation dimension, the largest Lyapunov exponent, and the Kolmogorov en- tropy, are estimated in the reconstructed phase space. The results indicate that the reverberation signals are nonlinear. The Volterra adaptive prediction method is introduced to model the oceanic reverberation signals. The reverberation time series can be predicted in short term with small prediction errors. A preliminary conclusion can be reached that the nonlinear low-dimensional dynamic sys- tem model is more suitable for modeling oceanic reverberation than the classical random AR model.