Design of Balanced Reactor Welded with Water-Cooled Aluminum Busbars

A new process of welding aluminum water-cooled busbars is proposed, It can not only reduce the weight and cost, but also improve the dynamic and thermal stability. Furthermore~ both finite element method analysis and a prototype test testify the advantages of the design which is not limited by load current and provides a new approach for water-cooled reactors.

Analysis and optimization of heat loss for water-cooled furnace roller

A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller＇s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The model is proved logical and credible by comparing calculated results and measured data. Then, the relationship between water flow velocity, inlet water temperature, furnace temperature and roller cross section temperature, outlet water temperature, water temperature rise, cooling water heat absorption was studied. The conclusions and recommendations are mainly as follows： l） Cooling water temperature rise decreases with the increase of water flow velocity, but it has small relationship with inlet water temperature; 2） In order to get little water scale, inlet water temperature should be controlled below 30 ℃. 3） The cooling water flow velocity should be greater than critical velocity. The critical velocity is 0.07 m/s and water flow velocity should be controlled within 0.4-0.8 m/s. Within this velocity range, water cooling efficiency is high and water temperature rise is little. If cooling water velocity increases again, heat loss will increase, leading to energy wasting.

Numerical Simulation on Subcooled Boiling Heat Transfer Characteristics of Water-Cooled W/Cu Divertors

In order to realize safe and stable operation of a water-cooled W/Cu divertor under high heating condition,the exact knowledge of its subcooled boiling heat transfer characteristics under different design parameters is crucial.In this paper,subcooled boiling heat transfer in a water-cooled W/Cu divertor was numerically investigated based on computational fluid dynamic（CFD）.The boiling heat transfer was simulated based on the Euler homogeneous phase model,and local differences of liquid physical properties were considered under one-sided high heating conditions.The calculated wall temperature was in good agreement with experimental results,with the maximum error of 5%only.On this basis,the void fraction distribution,flow field and heat transfer coefficient（HTC）distribution were obtained.The effects of heat flux,inlet velocity and inlet temperature on temperature distribution and pressure drop of a water-cooled W/Cu divertor were also investigated.These results provide a valuable reference for the thermal-hydraulic design of a water-cooled W/Cu divertor.

Preparation of Al-Zn-Mg-Cu alloy semisolid slurry through a water-cooled serpentine pouring channel

The semisolid slurry of Al-Zn-Mg-Cu alloy was prepared through a self-designed water-cooled copper serpentine pouring channel(WSPC) machine. Influences of pouring temperature, the number of turns and the cooling water flow rate on the microstructure of the semisolid Al-Zn-Mg-Cu alloy slurry were investigated. The results show that the semisolid Al-Zn-Mg-Cu alloy slurry with satisfactory quality can be generated by the WSPC when the pouring temperature is in the range between 680 ℃ and 700 ℃. At a given pouring temperature, the average grain size of primary α-Al decreases and the shape factor increases with the increase of the number of turns. When the cooling water flow rate is 450 L·h^(-1), the obtained semisolid slurry is optimal. During the preparation of the semisolid Al-Zn-Mg-Cu alloy slurry with low superheat pouring, the alloy melt has mixed inhibition and convection flow characteristics by "self-stirring". When the alloy melt flows through the serpentine channel, the chilling effect of the inner wall of the channel, the convection and mixed inhibition of the alloy melt greatly promote the heterogeneous nucleation and grain segregation. This effect destroys the dendrite growth mode under traditional solidification conditions, and the primary nuclei gradually evolve into spherical or nearspherical grains.

Optimization of the Water-Cooled Structure for the Divertor Plates in EAST Based on an Orthogonal Theory

An orthogoual experimental scheme was designed for optimizing a water-cooled structure of the divertor plate. There were three influencing factors： the radius R of the water- cooled pipe, and the pipe spacing L1 and L3. The influence rule of different factors on the cooling effect and thermal stress of the plate were studied, for which the influence rank was respectively R 〉 L1 〉 L3 and L3 〉 R 〉 L1. The highest temperature value decreased when R and L1 increased~ and the maximum thermal stress value dropped when R, L1 and L3 increased. The final optimized results can be summarized as： R equals 6 mm or 7 mm, L1 equals 19 mm, and L3 equals 20 mm. Compared with the initial design, the highest temperature value had a small decline~ and the maximum thermal stress value dropped by 19~ to 24~. So it was not ideal to improve the cooling effect by optimizing the geometry sizes of the water-cooled structure, even worse than increasing the flow speed, but it was very effective for dropping the maximum thermal stress value. The orthogoaal experimental method reduces the number of experiments by 80%, and thus it is feasible and effective to optimize the water-cooled structure of the divertor plate with the orthogonal theory.

Analysis of surface cracking in water-cooled rolls and heat transfer between furnace chamber and rolls in a direct flame furnace

In the direct fired furnace of a continuous annealing line, seal rolls are susceptible to deformation that leads to surface defects of steel strips. According to failure analysis, the reasons include improper structural design and heat imbalance. An improved design has been proposed to reduce stress concentration and thermal radiation. A heat transfer model has been employed to determine the proper water flow rate for roll cooling. Industrial application proves that seal rolls with the new design has less deformation and longer service life.

Fully Immersing Water-Cooled Radial Slab Laser and its Incoherent Beam Combination

A novel scheme of fully immersing water cooling is proposed for a Nd：glass radial slab laser. The slab medium is entirely immersed in the circulating water Ailing the pumping cavity, which enables much lower temperature and reasonably smaller thermal gradient in the slab medium. The radial slab is symmetrically and synchronously pumped by eight flash lamps, and produces multi-output beams with a total energy of 469md. Incoherent beam combination property of the multi-output beams is also investigated. The approach suggested here provides a way of scaling the slab lasers to much higher output levels and also a convenience for beam combinations.

The Corrected Simulation Method of Critical Heat Flux Prediction for Water-Cooled Divertor Based on Euler Homogeneous Model

An accurate critical heat flux（CHF） prediction method is the key factor for realizing the steady-state operation of a water-cooled divertor that works under one-sided high heating flux conditions.An improved CHF prediction method based on Euler＇s homogeneous model for flow boiling combined with realizable k-ε model for single-phase flow is adopted in this paper in which time relaxation coefficients are corrected by the Hertz-Knudsen formula in order to improve the calculation accuracy of vapor-liquid conversion efficiency under high heating flux conditions.Moreover,local large differences of liquid physical properties due to the extreme nonuniform heating flux on cooling wall along the circumference direction are revised by formula IAPWSIF97.Therefore,this method can improve the calculation accuracy of heat and mass transfer between liquid phase and vapor phase in a CHF prediction simulation of water-cooled divertors under the one-sided high heating condition.An experimental example is simulated based on the improved and the uncorrected methods.The simulation results,such as temperature,void fraction and heat transfer coefficient,are analyzed to achieve the CHF prediction.The results show that the maximum error of CHF based on the improved method is 23.7%,while that of CHF based on uncorrected method is up to 188%,as compared with the experiment results of Ref.[12].Finally,this method is verified by comparison with the experimental data obtained by International Thermonuclear Experimental Reactor（ITER）,with a maximum error of 6% only.This method provides an efficient tool for the CHF prediction of water-cooled divertors.

Creation and Development of Turbo-generators with Water-Cooled Stator and Rotor Windings in Shanghai Electrical Machinery Mfg Works

1. An Overview of Manufacture and Operation A turbine generator utilizing a new technology of electrical machinery industry, i.e. the windings of its stator and rotor all being inner water-cooled, was first successfully created in China and was known afterwards as a turbine generator with watercooled stator and rotor windings (Abbrev, TGWSR). The teachers from Zhejiang University came to Shanghai between

一种适于脉动条件的气液分离器的设计与研究

文中针对在流量脉动条件下,无罩、圆柱状、“柱+锥”状稳涡罩对气液分离器的分离性能及流场特性产生的影响,进行了数值模拟和试验研究,提出了旋流场脉动衰减程度评价指标———脉动衰减率(ηp),其值大小与脉动衰减性能成反比。研究结果显示:在流量脉动条件下,“柱+锥”状稳涡罩对于提高旋流场稳定性的能力最为显著,脉动衰减率为0.01028,分离效率最高可达95.15%;同时,运用高速摄像技术对两相流场中气核运动及变化形态进行可视化观测,掌握了基于流量脉动条件下,旋流场内气核的运移规律,并将其划分为4个阶段(断续阶段、汇聚阶段、融合阶段、最终阶段),发现“柱+锥”状稳涡罩旋流器的气核向中心轴线聚集趋势显著,形成具有向上运动形态的空气柱,对旋流场内脉动流有明显的抑制作用。

分段式排风系统异形构件阻力特性分析及优化

铝冷轧过程产生大量油雾,危害工人健康、破坏厂房环境,分段式排风系统虽可高效捕集油雾,但因含阻力特性未知的异形构件,导致系统风量无法精确按需分配。本文针对分段式排风系统中的环吸式排风罩和缝吸式半密闭罩,通过数值模拟方法研究其阻力特性,并进行减阻优化。研究发现,影响环吸式排风罩和缝吸式半密闭罩局部阻力系数的关键因素为进出口面积比,且二者呈指数关系;针对2种构件中涡产生的主要位置,采用结构优化的方式使阻力分别降低了28.6%和22.1%。本文可为铝冷轧排风系统管路设计提供参考。

基于PLC控制器的造纸机干燥部管理方案研究

为实现针对造纸机干燥部的自动化管理,节约造纸企业的蒸汽使用量,降低纸张生产成本,基于造纸机干燥部的基本工艺流程对闪蒸罐液位、气罩送风温度和气罩露点温度实施重点监控,并通过S7-300 PLC控制技术对相关环境的车间设备进行自动化控制。在此基础上,通过STEP7软件编辑自动化管理方案运行程序,并采用Win CC组态软件组建终端操作界面。经试验研究发现,所设计的系统终端操作界面友好直观,数据信息交互方便快捷,造纸企业5个月内的平均吨纸汽耗量下降了0.214吨,纸张生产成本进一步降低。

“童话故事”抑或“怪诞之作”?--论流变中的小红帽形象

考察文学作品中小红帽形象的流变史,可以将其分为三个阶段:十四世纪的口头文学、十七至十九世纪的传统童话和二十世纪之后的女性主义批评。口头文学中的小红帽无疑充满了怪诞特征,表现为各种血腥、暴力以及性暗示;传统童话中的小红帽则被赋予道德训诫的角色使命,是父权制度下男性对女性的规约,是权力话语的体现。进入二十世纪,女性主义批评家安吉拉·卡特对这个故事进行改写,实际上就是对这种权力话语的抵抗,她揭露出经典童话作为权力话语的载体而产生的非本质性以及文本反过来产生权力关系的怪诞机制,改变了传统童话中女性被凝视、被规训的结局,开辟了一个权力关系新空间。

某有机化学实验室项目通风空调系统设计

有机化学实验往往会产生对人体有害的气体,有效的通风空调系统可以避免有害物泄漏,以保证实验人员在工作环境里的安全和健康。不同的有机化学实验室要求不同,其通风空调系统设计也有相应的不同要求。合成实验室通风量大,但对房间温湿度要求不高;分析仪器实验室中仪器设备较多,发热量较大,且对环境温湿度有一定的要求。本文结合某实际工程,对不同功能化学实验室通风量的确定、新风送风温度及空调设置情况和通风系统控制进行了介绍。

基于改进粒子群算法的木材板材下料方法

木材板材在家具行业应用广泛,以绿色环保、节约能源为目的的木材板材优化下料已经成为研究的热点。木材板材下料优化问题属于二维矩形下料问题,是一种具有高度计算复杂性的问题。本研究主要针对单规格木材板材进行矩形零件下料问题,在木材板材长和宽都大于零件长和宽的情况下,通过建立二维下料的数学模型,采用标准粒子群算法、变邻域搜索算法、粒子群混合变邻域搜索算法分别进行求解,并以某企业的下料实例进行分析计算。首先,利用标准粒子群算法求解单规格板材下料问题;其次,利用变邻域搜索算法求解单规格板材下料问题。在获得局部最优解的基础上改变其邻域结构再进行局部搜索,找到另一个局部最优解,如此不断迭代,直到满足算法的终止条件,获得全局最优解;最后,利用粒子群变邻域搜索混合算法求解单规格板材下料问题。针对粒子群算法局部搜索能力较差、容易过早收敛的问题和具有较好包容性的特点,将变邻域搜索的思想融入粒子群算法中,使结果更加趋向全局最优。结果表明:粒子群变邻域搜索混合算法相比粒子群算法和变邻域算法效率都有显著提升,能显著提高该木材板材的利用率,增加企业经济效益。

柱状聚能药管聚能罩角度对煤层爆破增透效果试验研究

为解决传统预裂爆破煤体裂隙无序扩展导致增透效果不佳的问题,开展了聚能爆破药管不同聚能罩张开角度对煤层增透效果影响研究。通过建立聚能罩微元闭合理论模型,分析了随着聚能罩角度减少时形成聚能射流的速度和质量变化;以此为基础对聚能爆破增透机制进行了分析。在实验室搭建了可从煤体宏观裂纹和应变数据多角度对试验模型进行分析的双向加载气固耦合爆破相似模拟试验系统,对含瓦斯煤体试块进行普通爆破和不同聚能张开角爆破模拟对比试验。结果表明,使用聚能药包相较于普通爆破能够有效引导裂纹在聚能罩开口方向上定向发育;随着聚能罩角度减少,聚能爆破后形成的裂纹在聚能方向上更加平滑,裂纹宽度也随之增加,试块剖面更加平整;根据超动态应变仪反演结果,1号测点60°、80°和100°聚能爆破的压应力峰值分别为普通爆破的1.52倍,1.26倍和1.08倍,且60°聚能爆破到达应力峰值的时间最短,表明随着聚能罩开口的减小,聚能方向上能量集中现象越明显。通过ANSYS/LS-DYNA软件对4种不同角度的聚能爆破进行对比分析。模拟结果中60°聚能爆破初始形成的聚能射流有效应力最大,聚能方向产生的裂纹最长。试验和模拟结果表明通过使用60°聚能药包可得到更好的爆破效果,研究成果对松软高瓦斯煤层聚能爆破增透有一定的参考意义。

铝熔炼炉排烟罩捕集性能分析及优化数值模拟

铝加工厂房熔炼工艺中高温烟尘散发强度大、浓度高,对建筑室内外环境和人员健康危害大。为提高铝熔炼炉局部排烟罩捕集效率,本文研究了排烟罩捕集效率与量纲一排风量(排烟罩排风量/烟尘散发量)的关系;基于消涡原理及气流卷吸特性,提出了排烟罩捕集性能优化方法。研究表明,当量纲一排风量小于3.2时,增大排风量会显著提升排烟罩的捕集效率,为风量经济区。排烟罩几何特征优化后,在风量经济区内烟尘逃逸率降低了20%左右,系统排风量降低了6.1%~44.1%。

基于胡德政策工具的试点地区DIP政策文本量化分析

目的基于胡德政策工具视角对我国按病种分值付费(Diagnosis Intervention Packet,DIP)政策进行文本挖掘,对政策内容进行词频分析和聚类分析,探索各试点地区政策实际,进一步剖析原因,为后续政策调整与施行提供科学参考依据。方法纳入政策文本来自地方医疗保障局、地方卫生健康委员会、地方人民政府门户网站以及北大法宝等平台,从中选取了与DIP相关程度较高的政策文件。采用NVivo 20.0软件进行文本编码、词频分析,基于胡德政策工具与地区分布维度,进一步探讨DIP政策具体情况。结果共纳入27份政策文本,涵盖了所有试点省份,政策编码共1707条。权威型、财政型、信息型、组织型政策工具分别占54.9%,20.3%,16.9%和7.9%。东、中、西、东北部地区的编码参考点占比分别为23.0%、20.2%、44.5%、8.7%。结论各试点地区DIP政策工具使用中,侧重权威型工具而对组织型工具的使用较少。在权威型政策工具中,以机制建设类子工具使用居多,标准规范类子工具使用偏少。各试点地区政策工具侧重不同,政策工具使用应因地制宜。

用于铝压延厂房油雾控制的环吸式排风罩设计方法

环吸式排风罩是针对铝压延加工工艺油雾散发特征而提出的一种高效捕集设备,可以大幅降低系统风量,从而减少能耗和降低碳排放量,但目前仍缺乏此类排风罩的通用设计方法。本文选取10个铝压延车间铝冷轧机及排风罩为研究对象,探究了不同轧机尺寸组合下排风罩罩口处污染物扩散断面尺寸和排风罩捕集性能,通过回归分析得到了排风罩罩口设计尺寸和设计风量的计算方法,可供工程设计人员参考。

Hood联合Clipless技术对机器人辅助前列腺癌根治术后患者尿控及勃起功能的影响

目的探讨Hood联合无血管夹(Clipless)技术对机器人辅助前列腺癌根治术(RARP)后患者尿控及勃起功能恢复的影响。方法回顾性分析2020年6月至2021年6月接受Hood联合Clipless技术RARP患者的临床资料,共纳入37例术前国际勃起功能指数(IIEF-5)评分>21分的患者。患者年龄平均58.9岁(45~66岁),术前初诊平均t PSA13.24ng/ml(2.7~23.0ng/ml)。所有患者术前经会阴前列腺MRI/超声融合穿刺明确病理诊断,Gleason评分平均7.3分(6~8分)。所有患者术前均行多参数MRI检查及全身核素扫描明确肿瘤分期,术前临床分期为T_(2a)期10例、T_(2b)期8例、T_(2c)期19例。记录患者手术参数及术后3、6、9和12个月的IIEF-5评分。结果37例患者术中平均出血量56.5ml(20~110ml),无输血及切缘阳性病例;患者术后平均住院时间7.3d(5~8d),术后1周拔除尿管,34例患者拔除尿管24h内恢复尿控;术后3、6、9和12个月分别有48.7%、75.7%、86.5%和91.9%的患者恢复勃起功能,患者IIEF-5评分>21分。术后12个月随访无生化复发。结论Hood联合Clipless技术RARP安全可行,在游离前列腺侧蒂时采用Clipless技术,不增加手术出血量及切缘阳性率,术后患者即刻尿控及勃起功能恢复较好。