Thermal hydraulic behaviors during loss of RHR system at mid-loop operation of Chinese 300 MWe PWR NPP

Thermal hydraulic behavior of nuclear power plant (NPP) is analyzed by using mechanistic computer code for loss of residual heat removal (RHR) system during mid-loop operation of Chinese 300 MWe two-loop pressurized water reactor is presented. In the absence of recovery of RHR or other accident management measures, the reactor core will be uncovered for a long term resulting in core heat-up, degradation and relocation to the lower plenum. The effectiveness of available mitigate measures, such as safety injection system, gravity feed from refueling water storage tank (RWST) and steam generator (SG) reflux-condensation, are investigated. Coolant injection is highly effective in halting the accident progression and make the core recovered. The cooling capability of SG reflux-condensation has a relationship with different availabilities of steam generators and decay heat power. 6 days after shutdown, 2SG operation can keep the water level at mid-line of hot leg. 12 days after shutdown, both 2SG operation and 1SG operation can keep the water level at mid-line of hot leg. The analyses also indicate that the cooling mechanism of safety injection system is more effective than gravity feed from RWST and SG reflux-condensation. Through confirming the success criteria of SG reflux-condensation, time windows can be devided. Then, event trees for loss of RHR system under mid-loop operation are built with considering the analysis results and abnormal procedure.     

液压驱动式泵-喷嘴系统特性研究

对一种电子控制液压驱动式泵-喷嘴供油系统进行了建模与仿真,在AMEsim环境下使用机械、液压和控制部件的标准元件搭建仿真模型,用一维集总参数法进行仿真计算.利用试验测出的柱塞升程和柱塞腔内压力以及循环供油量检验模型的准确性和精度,在此基础上通过对仿真模型的优化,计算了不同控制参数下的喷油规律,对该喷油器的改进设计及其与发动机的合理匹配和供油系统控制策略的研究具有一定的指导意义.     

The Formation of a Tokamak-like Plasma in Initial Experiments Using an Outboard Plasma Gun Current Source

Solenoid-free tokamak startup via point-source DC helicity injection is demonstrated on the Pegasus Toroidal Experiment using a high current density, low impurity plasma gun mounted near the outboard midplane. A threshold in the vacuum vertical magnetic field strength that allows the injected current filament to relax into a tokamak-like topology is observed. A simple 2-D model of the vacuum magnetic field suggests this threshold is the maximum field strength that allows a toroidally connected field null to form. Discharges with I _p ≈ 17 kA are produced using less than 2 kA of injected current and no inductive drive. The tokamak-like discharges exhibit current decay times about five times longer than the injected current decay, expansion of the plasma into the vacuum region and a significant increase in the line-integrated density.     

保护盖注射模设计与工艺研究

通过对保护盖工艺的分析,设计了一模两腔的注射模具.详细地叙述了模具成形零件的设计、液压侧抽芯机构、浇注系统和其他结构的设计过程,以及模具工作过程.     

引燃策略对天然气直喷发动机射流燃烧及排放的影响

基于计算流体力学(computational fluid dynamics,CFD)软件CONVERGE研究了天然气直喷发动机的高压天然气射流混合、引燃燃烧及排放物生成等基础过程,详细分析了引燃方式和引燃距离对这些基础过程的影响。结果表明：高压直喷天然气射流能够明显促进引燃柴油喷雾发展与混合,但引燃柴油喷射对天然气射流发展影响不明显。高压直喷天然气射流火焰中心存在温度较低而天然气浓度较高的火焰内陷区,该内陷区是碳烟的主要生成区域,碳烟高浓度区位于火焰内陷区中后部。与引燃方式相比,引燃距离对火焰浮起长度、火焰内陷长度及NO_x和碳烟排放有更明显影响。随引燃距离增加,火焰浮起长度和NO_x排放增加,火焰内陷长度和碳烟排放减小。柴油喷入天然气中引燃在3种引燃方式中具有最高的放热率峰值和最短的燃烧持续期,其NO_x和碳烟排放最低,但甲烷逃逸量最高。     

萨中开发区萨零组油层开发试验研究

萨中开发区目前已进入高含水后期开发阶段,萨零组储层作为高含水后期开发的接替潜力资源,具有一定的油气丰度.室内实验和现场实践证明,萨零组油层属低渗透、强敏感性储层,需添加粘土稳定剂才能实现注水开发;萨零组油层原油粘度大、储层物性差、自然产能低,需要进行防膨压裂才能获得较高产能.试验通过添加粘土稳定剂技术改造萨零组油层,取得了较高的产液能力,初期平均单井日产油达2.0 t以上.针对萨零组储层,粘土稳定剂有效地解决了强水敏问题,取得了较好的注水开发效果,证实了萨零组储层注水开发的可行性.     

江苏油田注水井套管软密封保护技术

针对注水井套管腐蚀严重的问题,在注水井油套环空某一指定位置使用化学剂形成一个环状黏弹性密封塞,同时筛选适合油田实际情况的防腐剂、杀菌剂,配制相应的套管保护液,以保护油套环空。该技术具有施工简单、隔离性能好、有效期长和可用于套管变形井等特点。通过在江苏油田15口井的现场应用,工艺成功率100％,有效解决了污水回注井油套环空防腐困难的问题,降低了油套环空的腐蚀速度,延长了油、套管使用寿命。     

表面活性剂在特殊油藏原油开采中的一些应用

分析了稠油油藏、低渗透油藏在常规开采中存在的问题和缺陷,讨论了表面活性剂在稠油热采、稠油化学吞吐（冷采）以及低渗透油藏降压增注方面的应用,并对不同应用研究中的关键技术进行了论述。     

软弱岩层中大断面硐室施工与支护技术研究

针对姑山铁矿和睦山矿区-300m水平井底车场中央变电所硐室围岩具有松散、软弱和破碎的特点,以软岩巷道支护理论为基础,提出了大断面硐室合理的支护结构与施工方法,简要分析了实现硐室稳定的支护机理,提出初次支护采用锚网喷与低预应力锚索支护,而二次支护采用锚注全断面支护,形成复合锚固支护结构,给出了硐室结构的具体支护参数和施工工艺。应用和现场监测结果表明,由初次锚网喷与锚索和二次锚注组成的复合支护结构满足了软岩地层中大断面硐室的支护要求,取得较好的技术与经济效果。     

水生物种基因转移微注射自动化技术

针对目前水生物种转基因注射时存在的手工操作注射效率及成功率低等缺点,研究用于水生物种基因转移的专用细胞自动注射技术。提出卵细胞自动定位输送、吸持、注射的方法。研制了细胞自动注射试验系统,进行鱼卵细胞自动注射试验研究,试验表明,在注射过程中可完成卵细胞的自动定位输送、吸持、注射;可完成未注射和已注射卵细胞的分离和计数;可实现注射过程的计算机控制。该技术的研究为实现水生物品种杂交及品种改良提供高效快捷培育方法。