1、天然氣流量計量概況
孔板流量計是(shi)目(mu)前(qian)作(zuo)為(wei)天(tian)然(ran)氣(qi)流(liu)量(liang)計(ji)量(liang)常(chang)用(yong)的(de)計(ji)量(liang)方(fang)式(shi)。在(zai)實(shi)際(ji)生(sheng)產(chan)中(zhong),由(you)於(yu)種(zhong)種(zhong)因(yin)素(su)孔(kong)板(ban)計(ji)量(liang)會(hui)存(cun)在(zai)一(yi)定(ding)的(de)誤(wu)差(cha),然(ran)而(er)計(ji)量(liang)儀(yi)表(biao)誤(wu)差(cha)大(da)是(shi)導(dao)致(zhi)天(tian)然(ran)氣(qi)孔(kong)板(ban)計(ji)量(liang)誤(wu)差(cha)偏(pian)高(gao)的(de)主(zhu)要(yao)原(yuan)因(yin);在我站的計量工作中,計量儀表誤差已嚴重影響天然氣流量計量的準確性。
2、降低天然氣流量計量誤差的方法
針對孔板計量方式,降低天然氣流量計量誤差的關鍵是降低計量儀表的誤差,而導致計量儀表誤差大的主要原因包括差壓變送器誤差、溫度傳感器誤差、天然氣含水高、冬季氣溫低四個方麵。
2. 1差壓變送器存在誤差的解決辦法
(1)采取由儀表工對差壓變送器每月進行校準的措施。
(2)采取對差壓變送器每周進行檢查的措施,檢查的重點分為:導壓管是否存在堵塞、腐蝕、凍結和泄露現象,導壓管與管道和變送器的連接處是否存在密封不嚴,有漏氣現象。
(3)caiquduidaoyaguanjinxinggongtongbaowendecuoshi,shilianggendaoyaguanchuzaixiangtongwendudehuanjing,mudeshiquebaoliangbiandaoyaguanzhijianbuhuiyinwenchaeryinqimidubutong,congerdaozhiyatouwucha。chundongliangjiwendudi,luolouzaikongzhongdedaoyaguanyouyuweizhisuozai、風向、是否朝陽、dianredaichanraobujundengyinsuzaochengwencha,congerdaozhiyatouwucha,zuizhongzaochenglejiliangwucha。duidaoyaguanjinxinggongtongbaowenhou,shilianggendaoyaguanchuyuxiangtongdehuanjingwendu,jiangdileyouyuwenchazaochengdejiliangwucha
2. 2溫度傳感器存在誤差的解決辦法
(1)采取由儀表工對溫度傳感器每(mei)月(yue)進(jin)行(xing)校(xiao)準(zhun)的(de)措(cuo)施(shi)。因(yin)為(wei)熱(re)電(dian)偶(ou)的(de)分(fen)度(du)值(zhi)隨(sui)使(shi)用(yong)時(shi)間(jian)和(he)使(shi)用(yong)條(tiao)件(jian)的(de)不(bu)同(tong)會(hui)發(fa)生(sheng)變(bian)化(hua)。所(suo)以(yi)如(ru)果(guo)經(jing)常(chang)進(jin)行(xing)監(jian)督(du)性(xing)校(xiao)驗(yan)或(huo)根(gen)據(ju)實(shi)際(ji)使(shi)用(yong)情(qing)況(kuang)安(an)排(pai)周(zhou)期(qi)校(xiao)準(zhun),就(jiu)可(ke)以(yi)減(jian)少(shao)不(bu)穩(wen)定(ding)性(xing)導(dao)致(zhi)的(de)誤(wu)差(cha)。
(2)采取了將熱電偶和動力電纜分開的措施。熱電偶hedonglidianlanxianzhuangzaitongyigenhuguannei,youyudonglidianlandianliuda,huixingchengqiangdianchang,wanqudedifanghaihuixingchengqiangcichang,erqiangdianchangheqiangcichanghuiduichayabiansongqihewenduchuanganqideweiruodianliuxinhaochanshengyingxiang,daozhixinhaobuzhunquezaochengjiliangwucha。
(3)采cai取qu定ding期qi對dui直zhi管guan段duan進jin行xing清qing理li的de措cuo施shi。既ji避bi免mian了le由you於yu天tian然ran氣qi中zhong的de雜za質zhi過guo多duo致zhi使shi熱re電dian偶ou極ji間jian與yu管guan壁bi絕jue緣yuan不bu良liang引yin起qi熱re電dian勢shi的de損sun耗hao而er造zao成cheng的de幹gan擾rao,又you避bi免mian了le雜za質zhi會hui附fu在zai熱re電dian阻zu上shang麵mian,阻zu礙ai了le熱re的de傳chuan導dao而er造zao成cheng的de誤wu差cha。因yin此ci,應ying保bao持chi管guan壁bi和he熱re電dian偶ou保bao護hu管guan外wai部bu的de清qing潔jie,以yi減jian小xiao溫wen度du傳chuan感gan器qi誤wu差cha。
2. 3天然氣含水高的解決辦法
(1)從源頭上保證進入天然氣管線的天然氣含水量達到標準,來氣先進入分離器脫水,從而降低天然氣的含水率;
(2)采取對分離器和易存水部位(如管線的低點)安裝放空裝置,進行定期排水放空的措施;
(3)采cai取qu對dui差cha壓ya流liu量liang計ji加jia電dian熱re帶dai的de措cuo施shi,提ti高gao天tian然ran氣qi的de溫wen度du,保bao證zheng氣qi體ti溫wen度du在zai水shui露lu點dian之zhi上shang,破po壞huai天tian然ran氣qi水shui合he物wu的de形xing成cheng條tiao件jian,使shi水shui合he物wu分fen解jie,不bu附fu著zhe在zai孔kong板ban和he導dao壓ya管guan進jin口kou處chu,從cong而er降jiang低di計ji量liang誤wu差cha提ti高gao天tian然ran氣qi流liu量liang計ji量liang的de準zhun確que性xing。
2. 4環境溫度低導致誤差的解決辦法
冬季氣溫低,引起誤差的主要原因是:兩liang根gen導dao壓ya管guan的de溫wen度du不bu一yi樣yang和he形xing成cheng較jiao多duo的de天tian然ran氣qi水shui合he物wu。因yin此ci,在zai冬dong季ji氣qi溫wen低di的de同tong時shi,對dui差cha壓ya流liu量liang計ji加jia電dian熱re帶dai和he可ke以yi使shi用yong天tian然ran氣qi行xing業ye中zhong最zui普pu遍bian的de方fang法fa,用yong化hua學xue製zhi劑ji甲jia醇chun來lai抑yi製zhi水shui合he物wu的de形xing成cheng。通tong過guo以yi上shang措cuo施shi,可ke以yi有you效xiao降jiang低di天tian然ran氣qi流liu量liang計ji量liang儀yi表biao的de誤wu差cha,保bao證zheng了le計ji量liang的de準zhun確que性xing,提ti升sheng生sheng產chan管guan理li水shui平ping,為wei天tian然ran氣qi管guan理li做zuo出chu了le有you意yi義yi的de探tan索suo和he嚐chang試shi。