控冷辊道中链条张紧装置的应用

介绍了高速线材轧机机组中,控冷辊道的工作情况和性能特点,并重点介绍了张紧装置在链轮、链条、集中传动中的实际应用。     

Research on experiments and action mechanism with water vapor as coolant and lubricant in Green cutting

Green cutting has become focus of attention in ecological and environmental protection. Water vapor is cheap, pollution-free and eco-friendly. Therefore water vapor is a good and economical coolant and lubricant. Water vapor generator and vapor feeding system were developed to generate and feed water vapor. Comparative experiments were carried out in witch YT15 (P type in ISO) tool was used in cutting C45 steel under the conditions of compress air, oil water emulsion, water vapor as coolant and lubricant and dry cutting, respectively. The experimental results showed that with water vapor as coolant and lubricant the cutting force is further reduced, the friction coefficient, the chip deformation coefficient and the surface roughness value decreased and the cutting temperature lowered. Kinetic model of penetration capillary in tool–chip interface of cutting fluid revealed that the lubricity effect is much better with water vapor as coolant and lubricant because of its excellent penetration performance and forming of low shearing strength lubrication layer. Therefore, the use of water steam as coolant and lubricant proves to be a green cutting technique.     

高速磨削冷却液的注入新方法

本文概述了磨削液的类型和作用，分析了磨削液注入方法对冷却效果的影响，介绍了磨削液注入新技术，研制了新型的冷却喷嘴，并建立了估算临界流量模型。     

冷轧带钢表面斑迹的产生原因和控制方法

介绍了本钢CDCM机组轧后带钢表面斑迹的研究情况,通过分析产生的原因对斑迹进行综合治理,降低锈蚀和乳化液斑缺陷,有效提高带钢表面质量。     

熔融液滴在冷却剂中的运动特性实验

设计、建立了研究高温熔融液滴与冷却剂相互作用的可视化实验装置,通过高速摄影记录熔融液滴的下落过程,获得了下落小球运动过程曲线,重点考察了液滴温度和冷却剂温度对液滴-冷却剂界面作用过程的影响.结果表明,熔融液滴穿过气-水界面后,将首先经历一个速度骤降-回升过程,之后液滴作减速运动下落;当冷却水温度一定时,高温熔融液滴温度越高,熔融液滴入水后下落速度越快;当熔融液滴温度一定时,冷却水温度越高,熔融液滴入水后下落速度越快.     

6CTA柴油机与发电机组冷却系统优化

通过对某160kW发电机组匹配6CTA柴油机后的高水温故障调查,开展了冷却系统的设计优化,包括冷却风扇、散热器及湿式排气管等,最终通过试验验证了设计优化方案是可行的,从而解决高水温故障。     

动力电池微细通道散热数值分析研究

动力电池对温度敏感度高,高温散热实现难度较大,尤其是极端环境温度和高倍率放电下。设计了一个微细通道电池液冷散热系统,针对系统进行不同放置方式、环境温度、冷却液入口温度、入口流速的影响研究。发现竖直方式电池组可获得较好的温度分布;环境温度变化对电池组温度变化影响较小;电池组温度与冷却液入口温度基本呈线性变化,冷却液入口流速增加可显著降低电池组最高温度,提高温度均匀性。最后对流道进行尺寸优化,增大高度是较好的优化方案。     

A methodology of risk assessment,management, and coping actions for nuclear power plant (NPP) hit by high-explosive warheads

A detailed Loss of Coolant Accident (LOCA) analysis in an AP1000 NPP was performed, followed by a definition of the vulnerability analysis principles, and analysis of blast loads and fragments impact created by a nearby explosion. The AP1000 NPP performs excellently to small-break LOCA due to in-structure shock, with the 10 CFR 50.46 Acceptance Criteria fully accomplished. Impulsive dynamic loads resulting from blast waves and fragments impact of GBU-28 (Guided Bomb Unit) were considered for a nearby explosion. We model the structure and the main reactor components using the MSC/Dytran code to obtain accurate internal acceleration levels at critical points. We account for the appropriate blast wave interaction with the soil and the soil interaction with the containment structure, rather than using empirical formulas. The model includes the shielding structure with its concrete base, the support structures for the reactor, the steam generators, and the pressurizer. The combined effect of bomb fragmentation and blast loading was also considered using a cylindrical fragmentation model and the blast model of Kingery-Bulmash, assuming a hemispherical charge. A comprehensive risk assessment methodology composed of four phases was developed. The methodology is comprised of: (I) System analysis, (II) Hazard analysis, (III) Damage assessment, and (IV) Risk analysis of the in-structure shock consequences. Using seismic fragility curves for analysis of the expected failure modes according to explosion events faced difficulties since no published data was found. Adjustments to these fragility curves were made using median acceleration limits on components designed to withstand airplane crash, together with standard deviations taken from the given earthquake fragility tables. The findings reveal that the probabilities of failure of the reactor coolant system components resulting from a GBU-28 nearby hit, namely the pressurizer, the cooling pumps, and valves are quite high (greater than 1∙10⁻⁴).     

The effects of cutting fluid application methods on the grinding process

It is well known that a boundary layer of air is entrained around a rotating grinding wheel. The effects of the boundary layer have been under some scrutiny in recent years with most research being based on trying to overcome the boundary layer. The current investigation aims to show through experiment and modelling, the effects of the boundary layer on cutting fluid application and how it can be used to aid delivery by increasing flow rate beneath the wheel. Results from three experiments with different quantities of cutting fluid passing through the grinding zone are presented.     

GF型长寿命合成切削液的研制及应用

以二丁基亚磷酸、多元胺、甲醛、壬基酚聚氧乙烯醚、硼酸为原料合成BP ,以蓖麻油酸和三乙醇胺为原料合成OE ,并添加高效杀菌剂及其它组分配置成GF型长寿命合成切削液。该产品具有优良的润滑性、防锈性、冷却性、清洗性、杀菌性 ,在集中循环系统中 ,可满足企业的各种进口及国产机床、磨床、车床、铣床等设备及各加工工艺 (车、镗、钻、扩、孔等 )的技术要求 ,具有连续使用三年不变质的独有品质 ,易处理 ,排放少 ,是一种环保型的绿色切削液 ,是长寿命合成切削液的一个突破