简介:摘 要 :为节省建设工期、减少占地面积,智能变电站通过采用预制舱,实现智能电网模块化、精细化、高密度管理。本文首先介绍了预制舱内产生静电的主要原因,以及静电现象对二次设备的危害,结合预制舱的结构特点,重点分析了预制舱内防止静电的措施。
简介:BasedonthetraditionalSmoothedParticleHydrodynamics(SPH)algorithm,thelinked-listsearchalgorithmcombinedwiththevariablesmoothinglengthandsquaresupportdomainwasputforwardtoimprovethecalculationefficiencyandguaranteethecalculationaccuracy.Thephysicalprocessofhighvelocityfragmentimpactonabroadsideliquidcabinwasprogrammedforsimulation.ThenumericalresultsagreedwellwiththoseofthegeneralsoftwareANSYSAUTODYN,whichverifiestheeffectivenessandfeasibilityofthenumericalmethod.Fromtheperspectiveoftheouterplatethicknessoftheliquidcabin,thewidthoftheliquidcabin,andincidentangleofthefragment,theinfluenceoftheseparametersonprotectivemechanismswasanalyzedtoprovideabasisforprotectivedesignofabroadsideliquidcabin.Resultsshowthattheinfluenceofouterplatethicknessisnotobvious;therefore,theconventionaldesigncanbeadoptedinthedesignoftheouterplate.Thewidthoftheliquidcabinhasagreatinfluenceontheresidualvelocityofthefragmentandthewidthoftheliquidcabinshouldbedesignedtobeaswideaspossibleunderthepremiseofmeetingotherrequirements.Thereisacertainincidentangleinwhichthevelocityattenuationofthefragmentismostobvious,andthehigh-pressurezoneneartheinnerplateisasymmetric.Theinnerplateofliquidcabinshouldbestrengthenedaccordingtothehullform,principaldimensions,andvulnerablepoints.
简介:摘要目的调查新型冠状病毒肺炎防控期间武汉地区方舱医院使用的CT方舱放射诊疗安全与放射防护水平。方法现场调查CT方舱的总体布局、放射防护设施及个人防护用品,并对CT方舱放射防护水平、CT剂量指数进行检测,按照国家相关标准进行分析与评价。结果CT方舱总体布局基本合理,设置的放射防护设施较齐全。检测23套CT方舱放射防护水平,合格20套,合格率87.0%,3套不合格CT方舱各存在1个超标检测点,经整改后均符合要求;检测7台方舱CT的体部剂量指数,加权CT剂量指数(CTDIW)变化幅度均在±7.5%内。结论CT方舱放射防护效果总体较好,可满足新型冠状病毒肺炎防控期间放射诊疗辐射安全与放射防护的要求。