简介:摘要介绍了核岛冷水系统(DEG)的主要核心设备——冷水机组的功能原理及其维修情况;阐述了1DEG101GF冷水机组在运行过程中出现的轴承损坏故障问题与处理方法;根据维修经验给出了冷水机组的后续运行维修改进措施。
简介:以聚己内酯(PCL)和二苯基甲烷二异氰酸酯(MDI)等为主要原料,分别采用二甘醇(DEG)、(2,2-二羟甲基丙酸(DMPA)、N-甲基二乙醇胺(MDEA)作为扩链剂合成聚氨酯预聚体,然后加入交联剂过氧化苯甲酰(BPO)进行自由基聚合,制备PCL/MDI/DEG新型聚氨酯水凝胶。研究扩链剂种类以及扩链剂DEG用量对聚氨酯水凝胶接触角、溶胀度、形貌等的影响,并研究扩链剂对聚氨酯水凝胶载氯霉素性能的影响。结果表明,以DEG为扩链剂制备的聚氨酯水凝胶亲水性最差,材料表面孔隙较少,氯霉素载药量最小,但前期药物释放速率比其它2种扩链剂制备的水凝胶更快。而以带有羧基的DMPA和带有叔氨基官能团的MDEA为扩链剂制备的聚氨酯水凝胶,亲水性较强,表面具有微孔结构,氯霉素载药量较大。随扩链剂DEG用量增加,聚氨酯水凝胶的溶胀度增大,接触角逐渐减小,表面形貌无明显变化。
简介:Thelocalpressuredistributionsandresistancecoefficients(f1andf2)throughthesharp180degturninarelativelyshort(L/De=4)two-passsmoothandrib-roughenedchannelwereinvestigatedforaReynoldsnumberrangeof1.0×10^3,9.0×10^3.Theribpitch-to-herghtratios(p/e)were5,10,and20,Theribheight-to-hydraulicdiamterratios(e/De)were0.025,0.050and0.10,andtheribanglesofattack(a)were90,45,60,-45,and-60deg.Ridswereinstallednotonlyinbeforeandafterturnregionsbutalsointurnregion.TheresultsshowthatresistancecoefficientsremainapproximatelyconstantwhenReynoldsnumberismorethan3.0×10^4,Theeffectsoftheribconfiguration(ribspacing,ribheight,andriborientation)ontheinletstraightductresistancecoefficient(f2)weresignificant,however,theireffectsontheoverallresistancecoefficient(f1)weredilutedbythesharp-180turn.Forthisrelativelyshortchannel(L/De=4),theoverallresistancecoefficient(f1)wasgreatlyaffectedbythesharpturn.Correlationsfortheoverallresistance(f1)andinletstraightductresistancecoefficient(f2)arepresented.