LNG動(dong)力(li)改裝(zhuang)船大(da)多(duo)(duo)將LNG儲(chu)(chu)(chu)罐(guan)布(bu)(bu)置(zhi)(zhi)(zhi)在后甲(jia)板上。這種布(bu)(bu)局有(you)(you)很多(duo)(duo)優(you)(you)點：首先，由于(yu)(yu)LNG的(de)(de)易燃性(xing)(xing)和(he)(he)易爆(bao)性(xing)(xing)，當布(bu)(bu)置(zhi)(zhi)(zhi)在甲(jia)板上時，意外(wai)泄漏的(de)(de)LNG可以(yi)釋放到(dao)大(da)氣(qi)中(zhong)，對(dui)船舶(bo)和(he)(he)人員的(de)(de)危害較小(xiao);其次，艙(cang)內(nei)(nei)一(yi)般空(kong)(kong)間(jian)有(you)(you)限，儲(chu)(chu)(chu)罐(guan)布(bu)(bu)置(zhi)(zhi)(zhi)難以(yi)有(you)(you)足夠的(de)(de)空(kong)(kong)間(jian)，開(kai)放式(shi)外(wai)甲(jia)板可滿足布(bu)(bu)置(zhi)(zhi)(zhi)要(yao)(yao)求：對(dui)于(yu)(yu)系統中(zhong)包含空(kong)(kong)溫(wen)(wen)汽化器的(de)(de)低(di)溫(wen)(wen)儲(chu)(chu)(chu)罐(guan)，艙(cang)外(wai)自然通風充足，有(you)(you)利于(yu)(yu)空(kong)(kong)溫(wen)(wen)汽化器的(de)(de)正常運行。在確(que)定了LNG儲(chu)(chu)(chu)罐(guan)的(de)(de)體(ti)積(ji)和(he)(he)結(jie)構后，需要(yao)(yao)對(dui)低(di)溫(wen)(wen)儲(chu)(chu)(chu)罐(guan)進行合理(li)的(de)(de)布(bu)(bu)置(zhi)(zhi)(zhi)。LNG儲(chu)(chu)(chu)罐(guan)可分(fen)為(wei)立式(shi)儲(chu)(chu)(chu)罐(guan)和(he)(he)臥式(shi)儲(chu)(chu)(chu)罐(guan)。立式(shi)儲(chu)(chu)(chu)罐(guan)的(de)(de)優(you)(you)點是占地面(mian)積(ji)小(xiao)，而(er)臥式(shi)儲(chu)(chu)(chu)罐(guan)穩定性(xing)(xing)好。大(da)多(duo)(duo)數陸地LNG生產和(he)(he)儲(chu)(chu)(chu)存設(she)備使(shi)(shi)用立式(shi)儲(chu)(chu)(chu)罐(guan)，而(er)大(da)多(duo)(duo)數運輸設(she)備和(he)(he)船舶(bo)儲(chu)(chu)(chu)罐(guan)使(shi)(shi)用臥式(shi)儲(chu)(chu)(chu)罐(guan)，因為(wei)它們對(dui)儲(chu)(chu)(chu)運過程有(you)(you)很高的(de)(de)性(xing)(xing)要(yao)(yao)求。目前，船用LNG低(di)溫(wen)(wen)儲(chu)(chu)(chu)罐(guan)一(yi)般分(fen)為(wei)甲(jia)板(艙(cang)外(wai))和(he)(he)艙(cang)內(nei)(nei)兩種布(bu)(bu)置(zhi)(zhi)(zhi)形式(shi)。LNG儲(chu)(chu)(chu)罐(guan)用于(yu)(yu)儲(chu)(chu)(chu)存LNG(液(ye)態天然氣(qi))、液(ye)氧液(ye)氮液(ye)氬儲(chu)(chu)(chu)存容器，要(yao)(yao)求設(she)備承(cheng)壓(ya)能力(li)好，保溫(wen)(wen)性(xing)(xing)能高。內(nei)(nei)膽(dan)不(bu)銹鋼適(shi)用于(yu)(yu)接觸低(di)溫(wen)(wen)介(jie)質，具有(you)(you)儲(chu)(chu)(chu)罐(guan)的(de)(de)承(cheng)壓(ya)安全性(xing)(xing)。夾套內(nei)(nei)抽真空(kong)(kong)3Pa以(yi)下，填(tian)充干燥珍珠巖，真空(kong)(kong)度不(bu)會反(fan)彈(dan)，使(shi)(shi)儲(chu)(chu)(chu)罐(guan)具有(you)(you)良好的(de)(de)保溫(wen)(wen)性(xing)(xing)能。內(nei)(nei)膽(dan)管道應(ying)用應(ying)力(li)補(bu)償設(she)計，防止(zhi)儲(chu)(chu)(chu)罐(guan)預冷和(he)(he)使(shi)(shi)用溫(wen)(wen)差變(bian)化引起(qi)的(de)(de)巨大(da)應(ying)力(li)破壞儲(chu)(chu)(chu)罐(guan)。安全閥為(wei)雙閥結(jie)構，便于(yu)(yu)檢(jian)測和(he)(he)更(geng)換。真空(kong)(kong)閥的(de)(de)前截止(zhi)閥便于(yu)(yu)真空(kong)(kong)閥的(de)(de)更(geng)換和(he)(he)檢(jian)測。

　　在儲存過(guo)程中，由(you)(you)于儲罐(guan)(guan)(guan)保溫夾層漏熱的影響，儲罐(guan)(guan)(guan)內的氣(qi)(qi)液溫度會逐漸升(sheng)(sheng)(sheng)高，并伴隨著(zhu)低溫液體的蒸發，從(cong)而(er)導致儲罐(guan)(guan)(guan)內氣(qi)(qi)體壓(ya)力(li)(li)的升(sheng)(sheng)(sheng)高。影響儲罐(guan)(guan)(guan)壓(ya)力(li)(li)變化(hua)的一個關(guan)鍵(jian)因素是儲罐(guan)(guan)(guan)的充(chong)滿(man)率(lv)。但是，對于LNG動力(li)(li)船的儲罐(guan)(guan)(guan)，由(you)(you)于LNG的不(bu)(bu)(bu)斷消耗，壓(ya)力(li)(li)不(bu)(bu)(bu)會自(zi)發上升(sheng)(sheng)(sheng)而(er)是下(xia)降(因此需要配備自(zi)增壓(ya)裝置)，因此不(bu)(bu)(bu)需要考慮傳(chuan)統(tong)意義上的充(chong)滿(man)率(lv)，只需要按照船級(ji)社規范的規定(ding)，不(bu)(bu)(bu)超過(guo)要求的充(chong)滿(man)率(lv)即(ji)可。目前規范要求額定(ding)充(chong)滿(man)率(lv)為90%，無論如何都不(bu)(bu)(bu)能超過(guo)95%。

　　液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣是氣體凈化(hua)(hua)(hua)(hua)、加(jia)壓、制(zhi)冷液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)后(hou)的多組分混合物。其(qi)溫度(du)和(he)組分的變(bian)化(hua)(hua)(hua)(hua)會(hui)導致(zhi)其(qi)密(mi)度(du)的變(bian)化(hua)(hua)(hua)(hua)。不同(tong)(tong)密(mi)度(du)的液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣在(zai)儲(chu)存過程(cheng)中(zhong)可(ke)能會(hui)因密(mi)度(du)的差異(yi)而分層。當不同(tong)(tong)層間的液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣在(zai)漏熱的影(ying)響下(xia)對流并最終混合時，可(ke)能會(hui)導致(zhi)液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣蒸發和(he)滾動事故(gu)。滾動事故(gu)的危(wei)害是不可(ke)預(yu)測的，所以要(yao)預(yu)防。為了(le)(le)防止先后(hou)充(chong)裝(zhuang)(zhuang)的液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣產生密(mi)度(du)差，在(zai)充(chong)裝(zhuang)(zhuang)前需要(yao)了(le)(le)解液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣的產地等信息，以確定新(xin)充(chong)裝(zhuang)(zhuang)的液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣成(cheng)分是否與(yu)罐(guan)內液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣成(cheng)分相(xiang)同(tong)(tong)或(huo)相(xiang)似，并盡量(liang)(liang)選擇成(cheng)分相(xiang)同(tong)(tong)的液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣進行(xing)充(chong)裝(zhuang)(zhuang)。同(tong)(tong)時，盡量(liang)(liang)在(zai)罐(guan)內液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣余(yu)量(liang)(liang)很(hen)小時(約(yue)10%)進行(xing)充(chong)裝(zhuang)(zhuang)。充(chong)裝(zhuang)(zhuang)時，推遲下(xia)進液(ye)(ye)(ye)時，盡量(liang)(liang)將(jiang)新(xin)充(chong)裝(zhuang)(zhuang)的液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣與(yu)罐(guan)內液(ye)(ye)(ye)化(hua)(hua)(hua)(hua)天(tian)(tian)(tian)(tian)(tian)然(ran)(ran)氣充(chong)分混合，防止分層發生。