每年4~9月yue是shi華hua南nan地di區qu雷lei電dian災zai害hai的de多duo發fa季ji節jie,雷lei電dian災zai害hai給gei人ren民min帶dai來lai生sheng命ming安an全quan和he財cai產chan損sun失shi。本ben文wen介jie紹shao雷lei電dian產chan生sheng的de原yuan因yin,對dui施shi工gong機ji械xie的de危wei害hai以yi及ji對dui雷lei電dian災zai害hai的de預yu防fang方fang法fa和he技ji術shu,這zhe些xie方fang法fa和he技ji術shu對dui同tong行xing在zai施shi工gong過guo程cheng中zhong預yu防fang雷lei電dian災zai害hai具ju有you普pu遍bian的de參can考kao意yi義yi。
1 雷電的產生
雷(lei)電(dian)是(shi)自(zi)然(ran)界(jie)中(zhong)一(yi)種(zhong)常(chang)見(jian)的(de)放(fang)電(dian)現(xian)象(xiang)。關(guan)於(yu)雷(lei)電(dian)的(de)產(chan)生(sheng)有(you)多(duo)種(zhong)解(jie)釋(shi)理(li)論(lun),通(tong)常(chang)我(wo)們(men)認(ren)為(wei)由(you)於(yu)大(da)氣(qi)中(zhong)熱(re)空(kong)氣(qi)上(shang)升(sheng),與(yu)高(gao)空(kong)冷(leng)空(kong)氣(qi)產(chan)生(sheng)摩(mo)擦(ca),從(cong)而(er)形(xing)成(cheng)了(le)帶(dai)有(you)正(zheng)負(fu)電(dian)荷(he)的(de)小(xiao)水(shui)滴(di)。當(dang)正(zheng)負(fu)電(dian)荷(he)累(lei)積(ji)達(da)到(dao)一(yi)定(ding)的(de)電(dian)荷(he)值時,會在帶有不同極性的雲團之間以及雲團對地之間形成強大的電場,從而產生雲團對雲團和雲團對地的放電過程,這就是通常所說的閃電和響雷。具體來說,冰晶的摩擦、雨滴的破碎、水滴的凍結、yuntidepengzhuangdengjunkeshiyunliziqidian。yibanyundedingbudaizhengdian,dibudaifudian,liangzhongjixingbutongdedianhehuishiyundeneibuhuoyunyudizhijianxingchengqiangdianchang,shunjianjuliefangdianbaofachuqiangdadedianhuohua,yejiushiwomenkandaodeshandian。zaishandiantongdaozhong,dianliujiqiang,wendukezhoushengzhi2萬攝氏度,氣壓突增,空氣劇烈膨脹,人們便會聽到爆炸似的聲波振蕩,這就是雷聲。
2 雷電危害的種類
雷擊的危害主要有三方麵:第di一yi是shi直zhi擊ji雷lei。是shi指zhi雷lei雲yun對dui大da地di某mou點dian發fa生sheng的de強qiang烈lie放fang電dian。它ta可ke以yi直zhi接jie擊ji中zhong設she備bei,雷lei電dian擊ji中zhong架jia空kong線xian,如ru電dian力li線xian,電dian話hua線xian等deng。雷lei電dian流liu便bian沿yan著zhe導dao線xian進jin入ru設she備bei,從cong而er造zao成cheng損sun壞huai。第di二er是shi感gan應ying雷lei。它ta可ke以yi分fen為wei靜jing電dian感gan應ying及ji電dian磁ci感gan應ying。當dang帶dai電dian雷lei雲yun(一般帶負電)出現在導線上空時,由於靜電感應作用,導線上束縛了大量的相反電荷。一旦雷雲對某目標放電,雷雲上的負電荷便瞬間消失,此時導線上的大量正電荷依然存在,並以雷電波的形式沿著導線經設備入地,引起設備損壞。當雷電流沿著導體流入大地時,由於頻率高,強qiang度du大da,在zai導dao體ti的de附fu近jin便bian產chan生sheng很hen強qiang的de交jiao變bian電dian磁ci場chang,如ru果guo設she備bei在zai這zhe個ge場chang中zhong,便bian會hui感gan應ying出chu很hen高gao的de電dian壓ya,以yi致zhi損sun壞huai。對dui於yu靈ling敏min的de電dian子zi設she備bei,尤you需xu注zhu意yi。第di三san是shi地di電dian位wei提ti高gao。當dang10kA的雷電流通過下導體入地時,我們假設接地電阻為10Ω,根據歐姆定律,我們可知在入地點A處電壓為100kV。因A點與B、C、D點相連,所以這幾點電壓都為100kV。而E點接地,其電壓值為0,設備的D點與E點間有100kV的電壓差,足以將設備損壞。據有關統計表明:直擊雷的損壞僅占15%,感應雷與地電位提高的損壞占85%。目mu前qian,直zhi擊ji雷lei造zao成cheng的de災zai害hai已yi明ming顯xian減jian少shao,而er隨sui著zhe城cheng市shi經jing濟ji的de發fa展zhan,感gan應ying雷lei和he雷lei電dian波bo侵qin入ru造zao成cheng的de危wei害hai卻que大da大da增zeng加jia。一yi般ban建jian築zhu物wu上shang的de避bi雷lei針zhen隻zhi能neng預yu防fang直zhi擊ji雷lei,而er強qiang大da的de電dian磁ci場chang產chan生sheng的de感gan應ying雷lei和he脈mai衝chong電dian壓ya卻que能neng潛qian入ru室shi內nei危wei及ji電dian視shi、電話及聯網微機等弱電設備。
3 防雷的方法和技術
在zai科ke學xue技ji術shu日ri益yi發fa展zhan的de今jin天tian,雖sui然ran人ren類lei不bu可ke能neng完wan全quan控kong製zhi暴bao烈lie的de雷lei電dian,但dan是shi經jing過guo長chang期qi的de摸mo索suo與yu實shi踐jian,已yi積ji累lei起qi很hen多duo有you關guan防fang雷lei的de知zhi識shi和he經jing驗yan,形xing成cheng一yi係xi列lie對dui防fang雷lei行xing之zhi有you效xiao的de方fang法fa和he技ji術shu。
(1)接閃 接(jie)閃(shan)就(jiu)是(shi)讓(rang)在(zai)一(yi)定(ding)範(fan)圍(wei)內(nei)出(chu)現(xian)的(de)閃(shan)電(dian)能(neng)量(liang)按(an)照(zhao)人(ren)們(men)設(she)計(ji)的(de)通(tong)道(dao)泄(xie)放(fang)到(dao)大(da)地(di)中(zhong)去(qu)。把(ba)一(yi)定(ding)保(bao)護(hu)範(fan)圍(wei)的(de)閃(shan)電(dian)放(fang)電(dian)捕(bu)獲(huo)到(dao),納(na)入(ru)預(yu)先(xian)設(she)計(ji)的(de)對(dui)地(di)泄(xie)放(fang)的(de)合(he)理(li)途(tu)徑(jing)之(zhi)中(zhong)。避(bi)雷(lei)針(zhen)是(shi)一(yi)種(zhong)主(zhu)動(dong)式(shi)接(jie)閃(shan)裝(zhuang)置(zhi),其(qi)功(gong)能(neng)就(jiu)是(shi)把(ba)閃(shan)電(dian)電(dian)流(liu)引(yin)導(dao)入(ru)大(da)地(di)。避(bi)雷(lei)線(xian)和(he)避(bi)雷(lei)帶(dai)是(shi)在(zai)避(bi)雷(lei)針(zhen)基(ji)礎(chu)上(shang)發(fa)展(zhan)起(qi)來(lai)的(de)。采(cai)用(yong)避(bi)雷(lei)針(zhen)是(shi)最(zui)首(shou)要(yao)、最基本的防雷措施。
(2)接地 接地就是讓已經納入防雷係統的閃電能量泄放入大地,良好的接地才能有效地降低引下線上的電壓,避bi免mian發fa生sheng反fan擊ji。過guo去qu有you些xie規gui範fan要yao求qiu電dian子zi設she備bei單dan獨du接jie地di,目mu的de是shi防fang止zhi電dian網wang中zhong雜za散san電dian流liu或huo暫zan態tai電dian流liu幹gan擾rao設she備bei的de正zheng常chang工gong作zuo。接jie地di是shi防fang雷lei係xi統tong中zhong最zui基ji礎chu的de環huan節jie。接jie地di不bu好hao,所suo有you防fang雷lei措cuo施shi的de防fang雷lei效xiao果guo都dou不bu能neng發fa揮hui出chu來lai。防fang雷lei接jie地di是shi防fang雷lei設she施shi安an裝zhuang驗yan收shou規gui範fan中zhong最zui基ji本ben的de安an全quan要yao求qiu。
(3)均壓連接 接jie閃shan裝zhuang置zhi在zai捕bu獲huo雷lei電dian時shi,引yin下xia線xian立li即ji升sheng至zhi高gao電dian位wei,會hui對dui防fang雷lei係xi統tong周zhou圍wei的de尚shang處chu於yu地di電dian位wei的de導dao體ti產chan生sheng旁pang側ce閃shan絡luo,並bing使shi其qi電dian位wei升sheng高gao,進jin而er對dui人ren員yuan和he設she備bei構gou成cheng危wei害hai。為wei了le減jian少shao這zhe種zhong閃shan絡luo危wei險xian,最zui簡jian單dan的de辦ban法fa是shi采cai用yong均jun壓ya環huan,將jiang處chu於yu地di電dian位wei的de導dao體ti等deng電dian位wei連lian接jie起qi來lai,一yi直zhi到dao接jie地di裝zhuang置zhi。金jin屬shu設she施shi、電(dian)氣(qi)裝(zhuang)置(zhi)和(he)電(dian)子(zi)設(she)備(bei),如(ru)果(guo)其(qi)與(yu)防(fang)雷(lei)係(xi)統(tong)的(de)導(dao)體(ti),特(te)別(bie)是(shi)接(jie)閃(shan)裝(zhuang)置(zhi)的(de)距(ju)離(li)達(da)不(bu)到(dao)規(gui)定(ding)的(de)安(an)全(quan)要(yao)求(qiu)時(shi),則(ze)應(ying)該(gai)用(yong)較(jiao)粗(cu)的(de)導(dao)線(xian)把(ba)它(ta)們(men)與(yu)防(fang)雷(lei)係(xi)統(tong)進(jin)行(xing)等(deng)電(dian)位(wei)連(lian)接(jie)。這(zhe)樣(yang)在(zai)閃(shan)電(dian)電(dian)流(liu)通(tong)過(guo)時(shi),所(suo)有(you)設(she)施(shi)立(li)即(ji)形(xing)成(cheng)一(yi)個(ge)“等電位島”,baozhengdaodianbujianzhijianbuchanshengyouhaidedianweicha,bufashengpangceshanluofangdian。wanshandedengdianweilianjiehaikeyifangzhishandiandianliurudizaochengdedidianweishenggaosuochanshengdefanji。
(4)分流 分(fen)流(liu)就(jiu)是(shi)在(zai)一(yi)切(qie)從(cong)室(shi)外(wai)來(lai)的(de)導(dao)線(xian)與(yu)接(jie)地(di)線(xian)之(zhi)間(jian)並(bing)聯(lian)一(yi)種(zhong)適(shi)當(dang)的(de)避(bi)雷(lei)器(qi)。當(dang)直(zhi)接(jie)雷(lei)或(huo)感(gan)應(ying)雷(lei)在(zai)線(xian)路(lu)上(shang)產(chan)生(sheng)的(de)過(guo)電(dian)壓(ya)波(bo)沿(yan)著(zhe)這(zhe)些(xie)導(dao)線(xian)進(jin)入(ru)室(shi)內(nei)或(huo)設(she)備(bei)時(shi),避(bi)雷(lei)器(qi)的(de)電(dian)阻(zu)突(tu)然(ran)降(jiang)到(dao)低(di)值(zhi),近(jin)於(yu)短(duan)路(lu)狀(zhuang)態(tai),將(jiang)閃(shan)電(dian)電(dian)流(liu)分(fen)流(liu)入(ru)地(di)。分(fen)流(liu)是(shi)現(xian)代(dai)防(fang)雷(lei)技(ji)術(shu)中(zhong)迅(xun)猛(meng)發(fa)展(zhan)的(de)重(zhong)點(dian),是(shi)防(fang)護(hu)各(ge)種(zhong)電(dian)氣(qi)電(dian)子(zi)設(she)備(bei)的(de)關(guan)鍵(jian)措(cuo)施(shi)。由(you)於(yu)雷(lei)電(dian)流(liu)在(zai)分(fen)流(liu)之(zhi)後(hou),仍(reng)會(hui)有(you)少(shao)部(bu)分(fen)沿(yan)導(dao)線(xian)進(jin)入(ru)設(she)備(bei),這(zhe)對(dui)於(yu)不(bu)耐(nai)高(gao)壓(ya)的(de)微(wei)電(dian)子(zi)設(she)備(bei)來(lai)說(shuo)仍(reng)是(shi)很(hen)危(wei)險(xian)的(de),所(suo)以(yi)對(dui)於(yu)這(zhe)類(lei)設(she)備(bei)在(zai)導(dao)線(xian)進(jin)入(ru)機(ji)殼(ke)前(qian)應(ying)進(jin)行(xing)多(duo)級(ji)分(fen)流(liu)。采(cai)用(yong)分(fen)流(liu)這(zhe)一(yi)防(fang)雷(lei)措(cuo)施(shi)時(shi),應(ying)特(te)別(bie)注(zhu)意(yi)避(bi)雷(lei)器(qi)性(xing)能(neng)參(can)數(shu)的(de)選(xuan)擇(ze),因(yin)為(wei)附(fu)加(jia)設(she)施(shi)的(de)安(an)裝(zhuang)或(huo)多(duo)或(huo)少(shao)地(di)會(hui)影(ying)響(xiang)係(xi)統(tong)的(de)性(xing)能(neng)。
(5)屏蔽 屏蔽就是用金屬網、箔、殼、管guan等deng導dao體ti把ba需xu要yao保bao護hu的de對dui象xiang包bao圍wei起qi來lai,阻zu隔ge閃shan電dian的de脈mai衝chong電dian磁ci場chang從cong空kong間jian入ru侵qin的de通tong道dao。屏ping蔽bi是shi防fang止zhi雷lei電dian電dian磁ci脈mai衝chong輻fu射she對dui電dian子zi設she備bei影ying響xiang的de最zui有you效xiao方fang法fa。
4 雷電對施工機械的危害及預防
gonglushigongzuoyechuzailutianhuanjingxiajinxing。shigongjixiededianqikongzhixitongtebieshiweidianzikongzhizhuangzhishouleidianzhijihuoleidianganyingguodianyasunhaidejilvhenda。jingzhugaosugongluqingyuanduandichushihuiyanshanqu,zaileiyujijieshileidianxijidegaofadiqu,meidangtiankongzhongwuyunmibudayulailinshi,leidianwangwanghuiduishigongjixiejinxingzhengmiandexiji;而er有you時shi即ji使shi在zai天tian空kong中zhong沒mei有you雨yu雲yun又you不bu下xia雨yu的de情qing況kuang下xia,感gan應ying雷lei也ye會hui時shi有you發fa生sheng,其qi產chan生sheng的de浪lang湧yong電dian壓ya入ru侵qin並bing損sun壞huai路lu麵mian攤tan鋪pu機ji的de微wei電dian控kong製zhi裝zhuang置zhi,為wei此ci,防fang雷lei工gong作zuo勢shi在zai必bi行xing。
(1)在瀝青混合料攬拌廠場安裝避雷針裝置 由(you)於(yu)瀝(li)青(qing)混(hun)合(he)料(liao)攪(jiao)拌(ban)設(she)備(bei)及(ji)其(qi)配(pei)套(tao)機(ji)械(xie)集(ji)中(zhong)在(zai)一(yi)個(ge)生(sheng)產(chan)廠(chang)場(chang)使(shi)用(yong),比(bi)較(jiao)容(rong)易(yi)進(jin)行(xing)集(ji)中(zhong)防(fang)雷(lei),為(wei)此(ci),在(zai)拌(ban)和(he)廠(chang)場(chang)安(an)裝(zhuang)避(bi)雷(lei)針(zhen)。避(bi)雷(lei)針(zhen)的(de)高(gao)度(du)高(gao)於(yu)攪(jiao)拌(ban)樓(lou)的(de)最(zui)高(gao)點(dian),達(da)到(dao)有(you)效(xiao)的(de)保(bao)護(hu)半(ban)徑(jing),防(fang)止(zhi)雷(lei)電(dian)對(dui)任(ren)何(he)一(yi)台(tai)作(zuo)業(ye)機(ji)械(xie)直(zhi)擊(ji)。避(bi)雷(lei)針(zhen)接(jie)地(di)要(yao)可(ke)靠(kao),由(you)於(yu)石(shi)灰(hui)岩(yan)山(shan)區(qu)的(de)地(di)質(zhi)土(tu)壤(rang)比(bi)較(jiao)幹(gan)硬(ying),土(tu)壤(rang)電(dian)阻(zu)值(zhi)過(guo)大(da),所(suo)以(yi)接(jie)地(di)網(wang)的(de)埋(mai)設(she)與(yu)廣(guang)珠(zhu)東(dong)線(xian)的(de)做(zuo)法(fa)不(bu)盡(jin)相(xiang)同(tong)。接(jie)地(di)網(wang)的(de)角(jiao)鋼(gang)樁(zhuang)點(dian)埋(mai)設(she)土(tu)坑(keng)要(yao)求(qiu)1.0m深左右,角鋼在土坑內要露出20cm左右,在土坑內按比例填滿木炭和顆粒生鹽作為降阻介質,生鹽與木炭的重量比例為1:10,即1kg生鹽摻合10kg木炭,然後填土複蓋。這樣可以確保接地電阻值在4yixia。dangleidianxijishiyoubileizhenjiqiyinxianjingguojiediwangxunsujiangqiangdadeleidiandianliuyinrudadi,fangzhileidianduijidianxitongdezhiji。ciwai,haiduiliqinghunheliaojiaobancaozuokongzhishijinxingpingbi,zuofashijiangcaozuoshineiweidianzikongzhixitongdegongzuojiedi、保護接地與金屬結構的控製室外殼用導體連接在一起,再通過接地引線引入地下接地網,使它們保持相等的地電位,預防靜電及雷電。
(2)對路麵攤鋪機械電氣控製裝置裝設過電壓保護器 youyulumiantanpujixieshisuishiyidongzuoyede,bukenengjizhongbilei,erchuzailutianhuanjingxiadeyidongjixiedianqikongzhizhuangzhizuirongyishouganyingleilangyongdianyaderuqin,liruliqingliqingtanpujikongzhilumianpingzhengduhekongzhijixiedingweideyalichuanganqidengjiushenshouqihai。weilebaohuzhexiekongzhilingmindujigaodejixieweidianzikongzhizhuangzhimianzaoganyingleilangyongdianyaruqinsunhui,genjumeitaijixiekongzhizhuangzhidebutonggouzaotedian,duiqizhuangsheguodianyabaohuqi。
5 結束語
雷lei電dian災zai害hai對dui機ji械xie電dian氣qi控kong製zhi裝zhuang置zhi特te別bie是shi微wei電dian子zi裝zhuang置zhi的de侵qin害hai是shi一yi種zhong常chang見jian的de自zi然ran災zai害hai,為wei避bi免mian雷lei電dian對dui其qi侵qin害hai,應ying根gen據ju機ji械xie電dian氣qi控kong製zhi設she備bei的de不bu同tong構gou造zao特te點dian而er采cai用yong不bu同tong的de防fang雷lei方fang法fa。隻zhi要yao合he理li地di選xuan用yong防fang雷lei設she備bei,應ying定ding期qi由you專zhuan業ye防fang雷lei公gong司si檢jian測ce防fang雷lei設she施shi,評ping估gu防fang雷lei設she施shi是shi否fou符fu合he國guo家jia規gui範fan要yao求qiu,施shi工gong項xiang目mu應ying設she立li防fang範fan雷lei電dian災zai害hai責ze任ren人ren,負fu責ze防fang雷lei安an全quan工gong作zuo,建jian立li各ge項xiang防fang雷lei安an全quan工gong作zuo,建jian立li各ge項xiang防fang雷lei設she施shi的de定ding期qi檢jian測ce,雷lei雨yu後hou的de檢jian查zha和he日ri常chang的de維wei護hu。施shi工gong單dan位wei在zai防fang雷lei設she施shi的de設she計ji和he建jian設she時shi,應ying根gen據ju地di質zhi、土壤、氣象、環境、被保護物的特點,雷電活動規律等因素綜合考慮,采用安全可靠、技術先進、經濟合理的設計施工。就會大大降低雷電災害帶來的損失。
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