广州珠江黄埔大桥南汊悬索桥主缆紧缆施工

珠江黄埔大桥南汊桥为单跨加劲钢箱梁悬索桥。在南汊悬索桥施工中,利用紧缆机进行主缆的紧缆作业。本文介绍南汊悬索桥主缆紧缆施工。     

岩滩电站工程缆机的选型与使用

介绍了岩滩水电工程缆机的选型。低平台缆机采用国产无塔缆机,开创了我国第一次使用无塔低架缆机的先例;高平台缆机采用进口的高架高速缆机,因种种原因其投产日期一再推迟,造成在高峰混凝土浇筑期没有发挥它应有的作用。本文对此两种缆机的性能、安装和使用情况等也作了较全面的介绍。     

无缆水下机器人水声图象处理系统设计

水声图象处理系统是无缆水下机器人的重要智能系统，它以ＴＭＳ３２０Ｃ３０高速数字信号处理器为核心，实时地完成水声图象压缩和水声目标参数计算（包括妨碍航行的障碍识别）等功能，本文给出了该系统软件、硬件的设计以及水池实验结果。     

深水缓波形脐带缆结构响应及参数敏感性分析

对某采用缓波形布局的深水脐带缆进行静态分析,得到了脐带缆的整体结构响应,包括脐带缆初始线形、有效张力和弯曲曲率的分布特性。同时对脐带缆缓波形布局下的总体布局参数进行了参数敏感性分析,得到了浮子段长度、浮力因子、浮子段起始位置及顶部悬挂角对脐带缆结构响应的影响。这些研究结果可以为深水脐带缆的缓波形布局设计提供参考。     

国产重型缆索起重机的发展与现状

本文是对50年来国产重型缆机的发展概况所作的阶段性技术总结.文中列举了外国重型缆机的概况、国产重型缆机三个发展阶段的概况和技术特点、重型缆机设计技术中的4大关键课题、国内外重型缆机在技术及其他方面的比较.从而认为现在国产重型缆机的技术水平已有较大提高,足以胜任当前国内大中型水利水电工程施工的需要,并具有很强的竞争能力.     

一种环空电缆头缆芯连接装置

本实用新型涉及一种缆芯连接装置,具体涉及一种环空电缆头缆芯连接装置,为解决目前缆芯连接费时费事和稳定性差的问题而设计的。     

缆阵绞车自动排缆系统的仿真分析

介绍了一种螺纹滑块一侧安装的缆阵绞车自动排缆系统的结构组成，分析了排缆系统的受力状况，并基于ADAMS对自动排缆系统进行了动力学仿真分析。分析结果为系统优化设计提供了依据。     

全海深ROV非金属铠装脐带缆动力学性能研究

为了全面评估全海深无人遥控潜水器(ROV)在不同模式配置、不同作业深度及工况下的脐带缆受力状态,提高脐带缆在全海深ROV系统应用的安全性和可靠性,开展了全海深ROV非金属铠装脐带缆动态力学理论分析与研究。针对铠缆系统水下运动具有小应变和大位移的几何特点,基于几何精确梁理论和虚功原理建立全海深非金属铠装脐带缆三维非线性有限元模型,基于所建立的动力学模型并结合工作母船升沉与海流联合激励,对脐带缆在全海深应用环境下扭转特性、在位运行等动态力学特性进行分析和研究。实验结果得出5000 m左右潜深为该全海深脐带缆系统的共振区域。研究结果可为全海深ROV非金属铠装脐带缆的安全应用及配套绞车优化设计提供理论依据。     

深海缓坡型脐带缆干涉分析研究

摘 要：对深海缓坡型脐带缆设计参数敏感性及管线之间干涉进行了研究。随着油气开采向深海加速迈进,脐带缆的结构变得更加复杂,重量不断增加,致使顶端张力越来越大,采用缓坡构型可有效减小顶端张力,然而浮力块的引入使得其非线性动力特性更加显著,容易与其他构件发生碰撞造成内部光纤等构件破坏,导致通信中断并影响到整个油气安全生产,因此有必要对深海缓坡型脐带缆进行干涉分析。对环境载荷作用下缓坡型脐带缆位构型的方位角、拖曳力系数及浮力块半径等影响参数进行分析,分析结果表明脐带缆位置构型与这些参数之间有很大相关性,并对SPAR平台上脐带缆之间及张力腿平台中脐带缆与张力腿之间的干涉问题进行了分析,所给出的结论便于设计人员更好理解缓坡型脐带缆干涉动力特性。     

埃塞俄比亚TEKEZE水电站20T辐射式缆机拆除方案的研究和应用

本文阐述了特克则(TEKEZE)水电站20t辐射式缆机的拆除方案.该方案结合特克则水电站工程混凝土双曲拱坝的坝体特点与辐射式缆机技术参数,确定了辐射式缆机的拆除位置与拆除顺序.并考虑到辐射式缆机拆除期间对大坝一线其他项目施工的影响,通过对工地现场进行详细分析,确定了主索拆除的临时承载索布置原则,选用了合理的临时承载索锚固方式,解决了辐射式缆机主索拆除的技术难点,具有一定参考价值.     

稳态混合磁体装置低温系统过冷槽的设计与优化

40 T稳态混合磁体装置的外超导磁体需要4.5K、5×105Pa、18 g／s超临界氦迫流冷却,拟采用盘管换热器将从制冷机出来的氦冷却至超临界状态.首先对氦制冷机进行混合模式的热力学分析,确定过冷槽中盘管换热器的进口压力及温度,进而提出阶梯管径理论,根据工程要求设计并优化盘管换热器,得出盘管换热器的盘绕方式及尺寸;最后...     

EAST超导托卡马克热负荷波动对低温系统液氦槽的影响

EAST超导托卡马克的纵场和极向场磁体均采用NbTi超导材料,由3.8 K超临界氦冷却.在托卡马克实验运行时,极向场的放电脉冲和等离子体破裂产生的交流损耗带来的热负荷增加,经过超临界氦流带到低温系统控制阀箱内的液氦槽和过冷槽,造成槽内的液氦蒸发量增加.蒸发的氦回到制冷机中,从而影响制冷机的稳定运行.通过对实际超临界管道和液氦槽、过冷槽中换热过程建立换热模型,进行热工分析,分析液氦槽和过冷槽中的压力等参数的变化,指导低温系统的设计.     

平行流换热器在R410A商用空调上的应用

基于一台R410A商用空调对平行流换热器和铜管-铝翅片换热器的性能、可靠性进行试验研究和对比分析。结果表明,平行流换热器能够有效提高空调的制冷性能并降低材料成本,平行流换热器经过1 200h中性盐雾试验后出现表面发黑现象,氦检未发生泄漏。平行流换热器的爆破压力一般在15.5～17.5MPa之间,可应用于R410A等高压工质的空调系统。     

Cryogenic helium gas circulation system for advanced characterization of superconducting cables and other devices

A versatile cryogenic test bed, based on circulating cryogenic helium gas, has been designed, fabricated, and installed at the Florida State University Center for Advanced Power Systems (FSU-CAPS). The test bed is being used to understand the benefits of integrating the cryogenic systems of multiple superconducting power devices. The helium circulation system operates with four sets of cryocooler and heat exchanger combinations. The maximum operating pressure of the system is 2.1 MPa. The efficacy of helium circulation systems in cooling superconducting power devices is evaluated using a 30-m-long simulated superconducting cable in a flexible cryostat. Experiments were conducted at various mass flow rates and a variety of heat load profiles. A 1-D thermal model was developed to understand the effect of the gas flow parameters on the thermal gradients along the cable. Experimental results are in close agreement with the results from the thermal model.     

Simulation of quench for the cable-in-conduit-conductor in HT-7U superconducting Tokamak magnets using porous medium model

A cable-in-conduit-conductor (CICC) consists of superconducting cable, copper, supercritical helium and conduit. To keep the operating temperature of superconducting cable lower than its current sharing temperature, the supercritical helium is forced flow through the CICC. The supercritical helium through the cable bundle has the complex directional changes due to the interaction between the supercritical helium and strands. The structure of CICC is characterized with the porous medium. The quench characteristics of CICC are analyzed by the model which the temperature difference between the strands and helium is assumed to be very small due to the heating induced flow to generate high heat transfer coefficient of supercritical helium. A moving mesh method is developed for the numerical solution of the problem with the steep drop for temperature and density of supercritical helium in the short front region of the normal zone. The computational mesh is obtained by equidistribution of a monitor function tailored for the functional variation of the arguments for density, temperature and velocity of supercritical helium. Existence and uniqueness of the discretised equations using a moving mesh are also established. The coupled equation for porous medium is solved using the finite element method with the artificial viscosity term. The validation of the code is tested by comparing it with the other codes with good accuracy. The converged properties of numerical solution due to quench in CICC are studied. We present preliminary estimates of the maximum conductor temperature rise and helium pressure during a quench in the inner layer of toroidal field (TF) magnet for HT-7U. The quench scenarios with different dump time constants of 6.25, 12, and 21.1 s are considered. The goal of such work is to guide the protection scheme and a detailed prediction of the quench evolution of magnet.     

Experimental test of a supercritical helium heat exchanger dedicated to EUROTRANS 150 kW CW power coupler

The coaxial power coupler needed for beta = 0.65 superconducting RF cavities used in the high energy section of the EUROTRANS driver should transmit 150 kW (CW operation) RF power to the proton beam. The estimated RF losses on the power coupler outer conductor in standing wave mode operation are 46 W. To remove these heat loads, a full scale copper coil heat exchanger brazed around the outer conductor was designed and tested using supercritical helium at T = 6 K as a coolant. Our main objective was to minimise the heat loads to cold extremity of SRF cavity maintained at 2 K or 4.2 K. A dedicated test facility named SUPERCRYLOOP was developed and successfully operated in order to measure the performance of the cold heat exchanger. The test cell used reproduces the realistic thermal boundary conditions of the power coupler mounted on the cavity in the cryomodule. After a short introduction, a brief discussion about the problem of power coupler cooling systems in different machines is made. After that, we describe the experimental set-up and test apparatus. Then, a heat exchanger thermal model will be developed with FEM code COSMOS/M to estimate the different heat transfer coefficients by comparison between numerical simulation results and experimental data in order to validate the design. Finally, thermo-hydraulic behavior of supercritical helium has been investigated as function of different parameters (inlet pressure, flow rate, heat loads).     

凹陷阵列印刷电路板式换热器里超临界甲烷换热和流动特性模拟研究

为了强化液化甲烷在印刷电路板式微通道换热器中的换热能力,提出了一种凹陷阵列的微小通道换热器整体性能提高的被动式强化技术并进行了数值模拟验证。研究了流体温度范围125—265 K范围内的超临界甲烷在凹陷阵列结构微通道内的换热和流动特性,考察了凹陷阵列微通道和光滑微通道下,流体温度、质量流量、雷诺数和进口压力对传热系数、努塞尔数、摩擦因子和综合效益系数(PEC)的影响。此外,通过凹陷结构的局部流动特性分析强化换热机理,数值模拟结果表明相较于光滑微通道,凹陷阵列微通道的换热特性得到大大强化,且随雷诺数(由质量流量或者流体温度改变)的增大而增强,而摩擦因子只是有较弱的劣化。     

5 kW@4.5 K氦低温系统一级板翅式换热器优化设计

以5 k W@4.5 K制冷当量的CFETR TF线圈测试用的氦制冷机第一级主换热器为对象,采用混合遗传算法,在满足换热要求、压降限制、现有制造工艺和结构强度等前提下,对换热器的体积进行优化。结果表明,与常用的板翅式换热器商用软件Aspen MUSE~(TM)设计计算的结果相比,基于遗传算法的优化过程可以快速高效地搜索到以体积最小化为目标的全局最优解,其结构尺寸可由原先设计的4.485 m×0.900 m×0.863 m缩小到3.032 m×0.721 m×0.594 m。     

50 kA超导变压器杜瓦及高温超导电流引线的设计与优化

CICC超导导体性能测试用50 kA超导变压器由初级线圈和次级线圈组成,初级线圈浸泡在4.2 K液氦低温杜瓦中,次级线圈为CICC导体采用4.2 K/354 637 Pa超临界氦迫流冷却,液氦和超临界氦均由500 W/4.5 K制冷机提供,变压器低温杜瓦的理论液氦蒸发率为1.52 L/h。为减少电流引线漏热,超导变压器采用B i-2223/AgAu高温超导(HTS)二元电流引线,并且在颈管中部设计了一个新型的直接用液氮冷却的热截流装置来截断电流引线高温端的热流;最后对铜电流引线部分进行了尺寸优化计算,得到最佳截面积和直径分别为28 mm2和6 mm。     

三角形波纹板式溶液热交换器传热特性研究

为了解三角形波纹板式溶液热交换器的传热特性，通过对其物理数学模型的求解，并与平板式溶液热交换器相对比，得到了三角形波纹板式溶液热交换器的流动、传热特性以及不同溶液流速对其传热性能的影响。研究三角形波纹板式溶液热交换器的波纹形状对其流动、传热性能的影响，得到波纹长度、波纹夹角与换热器的传热系数、换热器内流体压降的关系，其结果可为溶液热交换器的设计与优化提供依据与理论指导。