1834年(nian),英國的(de)(de)雅可比·珀金斯試制(zhi)(zhi)(zhi)(zhi)成功(gong)(gong)人力轉(zhuan)動的(de)(de)用乙醚為(wei)工質的(de)(de)可以連續工作(zuo)的(de)(de)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機。1844年(nian),美國的(de)(de)J.戈里(li)試制(zhi)(zhi)(zhi)(zhi)了(le)(le)用空(kong)氣為(wei)工質的(de)(de)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機,用在醫院(yuan)中(zhong)制(zhi)(zhi)(zhi)(zhi)冰和(he)(he)冷(leng)(leng)(leng)(leng)卻空(kong)氣。1872~1874年(nian),D.貝爾和(he)(he)C.von林德分(fen)別(bie)在美國和(he)(he)德國發(fa)明了(le)(le)氨壓(ya)縮(suo)機,并制(zhi)(zhi)(zhi)(zhi)成了(le)(le)氨蒸氣壓(ya)縮(suo)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機,這是(shi)現代壓(ya)縮(suo)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機的(de)(de)發(fa)端。19世紀50年(nian)代,法國的(de)(de)卡雷(lei)兄弟先(xian)后研(yan)(yan)制(zhi)(zhi)(zhi)(zhi)成功(gong)(gong)以硫酸和(he)(he)水(shui)為(wei)工質的(de)(de)吸收(shou)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機和(he)(he)氨水(shui)吸收(shou)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機。1910年(nian)出現了(le)(le)蒸汽(qi)噴射式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機。1930年(nian)出現了(le)(le)氟利昂(ang)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)劑,促進了(le)(le)壓(ya)縮(suo)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機的(de)(de)迅速發(fa)展。1945年(nian),美國研(yan)(yan)制(zhi)(zhi)(zhi)(zhi)成功(gong)(gong)溴化銀吸收(shou)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機。
①壓(ya)(ya)縮(suo)(suo)(suo)式(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)機(ji)(ji)(ji)。依(yi)(yi)靠(kao)壓(ya)(ya)縮(suo)(suo)(suo)機(ji)(ji)(ji)的(de)(de)作用提高(gao)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)劑的(de)(de)壓(ya)(ya)力以實現制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)循環,按制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)劑種(zhong)(zhong)類又可(ke)分為蒸(zheng)(zheng)氣(qi)壓(ya)(ya)縮(suo)(suo)(suo)式(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)機(ji)(ji)(ji)(以液壓(ya)(ya)蒸(zheng)(zheng)發制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)為基(ji)礎,制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)劑要發生(sheng)周期性的(de)(de)氣(qi)-液相(xiang)變)和(he)氣(qi)體(ti)壓(ya)(ya)縮(suo)(suo)(suo)式(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)機(ji)(ji)(ji)(以高(gao)壓(ya)(ya)氣(qi)體(ti)膨脹制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)為基(ji)礎,制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)劑始終處(chu)于氣(qi)體(ti)狀態)兩種(zhong)(zhong),現代制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)機(ji)(ji)(ji)以蒸(zheng)(zheng)氣(qi)壓(ya)(ya)縮(suo)(suo)(suo)式(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)機(ji)(ji)(ji)應(ying)用最廣。②吸(xi)(xi)(xi)收(shou)式(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)機(ji)(ji)(ji)。依(yi)(yi)靠(kao)吸(xi)(xi)(xi)收(shou)器(qi)(qi)-發生(sheng)器(qi)(qi)組(熱化(hua)學壓(ya)(ya)縮(suo)(suo)(suo)器(qi)(qi))的(de)(de)作用完成制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)循環,又可(ke)分為氨水吸(xi)(xi)(xi)收(shou)式(shi)、溴(xiu)化(hua)鋰(li)吸(xi)(xi)(xi)收(shou)式(shi)和(he)吸(xi)(xi)(xi)收(shou)擴散式(shi)3種(zhong)(zhong)。③蒸(zheng)(zheng)汽噴射(she)式(shi)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)機(ji)(ji)(ji)。依(yi)(yi)靠(kao)蒸(zheng)(zheng)汽噴射(she)器(qi)(qi)(噴射(she)式(shi)壓(ya)(ya)縮(suo)(suo)(suo)器(qi)(qi))的(de)(de)作用完成制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)循環。④半(ban)導(dao)體(ti)制(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)器(qi)(qi)。利用半(ban)導(dao)體(ti)的(de)(de)熱-電效應(ying)制(zhi)(zhi)(zhi)(zhi)取(qu)冷(leng)(leng)(leng)量。
制冷(leng)(leng)機(ji)的主要(yao)性(xing)能(neng)指(zhi)標(biao)有工作溫(wen)(wen)度(對蒸(zheng)氣壓縮(suo)式(shi)制冷(leng)(leng)機(ji)為蒸(zheng)發溫(wen)(wen)度和(he)冷(leng)(leng)凝溫(wen)(wen)度,對氣體(ti)(ti)壓縮(suo)式(shi)制冷(leng)(leng)機(ji)和(he)半導體(ti)(ti)制冷(leng)(leng)器為被冷(leng)(leng)物體(ti)(ti)的溫(wen)(wen)度和(he)冷(leng)(leng)卻介(jie)質的溫(wen)(wen)度),制冷(leng)(leng)量(制冷(leng)(leng)機(ji)單位時(shi)間(jian)內從被冷(leng)(leng)卻物體(ti)(ti)移去的熱(re)(re)量)、功率或耗(hao)熱(re)(re)量、制冷(leng)(leng)系數(衡(heng)量壓縮(suo)式(shi)制冷(leng)(leng)機(ji)經濟性(xing)的指(zhi)標(biao),指(zhi)消耗(hao)單位功所能(neng)得到的冷(leng)(leng)量)以(yi)及熱(re)(re)力系數(衡(heng)量吸(xi)收式(shi)和(he)蒸(zheng)汽(qi)噴射式(shi)制冷(leng)(leng)機(ji)經濟性(xing)的指(zhi)標(biao),指(zhi)消耗(hao)單位熱(re)(re)量所能(neng)得到的冷(leng)(leng)量)等。
制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)可分(fen)為:壓縮式(shi)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)、吸(xi)(xi)收式(shi)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)、蒸汽(qi)噴(pen)射式(shi)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji),半導體制(zhi)(zhi)冷(leng)(leng)(leng)(leng)。其中蒸汽(qi)壓縮式(shi)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(活塞(sai)式(shi)、回轉(zhuan)式(shi)、螺桿式(shi)、離心(xin)式(shi))、吸(xi)(xi)收式(shi)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)和蒸汽(qi)噴(pen)射式(shi)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)應用較為廣(guang)泛。我國(guo)除少數大(da)冷(leng)(leng)(leng)(leng)量和特殊用途的冷(leng)(leng)(leng)(leng)凍機(ji)外,一般用途的活塞(sai)式(shi)、離心(xin)式(shi)、螺桿式(shi)、渦(wo)旋(xuan)式(shi)、溴化鋰(li)吸(xi)(xi)收式(shi)、蒸汽(qi)噴(pen)射式(shi)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji),以及冷(leng)(leng)(leng)(leng)凍、冷(leng)(leng)(leng)(leng)藏、低溫試驗等設備都能自己制(zhi)(zhi)造。
各種類型制冷機主要(yao)特點(dian)如下(xia):
1.壓縮制冷
1)螺桿式(shi)制(zhi)冷(leng)機:結(jie)構簡(jian)單、易損(sun)件少、使用(yong)壽命長(chang)、單級壓(ya)縮(suo)比高,在大(da)中型制(zhi)冷(leng)量范圍內有取代活塞式(shi)的(de)趨勢。
2)活塞式制冷機(ji)(ji):技術發(fa)展比較成(cheng)熟,效率高(gao),使用溫度范圍廣(guang),可制成(cheng)大中(zhong)小型各種規格(ge)產品,是各種制冷機(ji)(ji)中(zhong)應用最廣(guang)的機(ji)(ji)種。
3)離心式(shi)制冷(leng)(leng)機(ji):利(li)用高(gao)速旋轉的葉輪使制冷(leng)(leng)劑(ji)氣(qi)體獲得動能,然(ran)后通過擴(kuo)壓器提高(gao)其壓力并冷(leng)(leng)卻液化,節流而制冷(leng)(leng)。具(ju)有結構緊湊,單機(ji)制冷(leng)(leng)量大,可進行能量調節等特點(dian)。用于(yu)空(kong)調的機(ji)器多采用R11、R12制冷(leng)(leng)劑(ji)。
2.吸收制冷
利用(yong)吸(xi)收劑(ji)對制(zhi)(zhi)冷(leng)(leng)劑(ji)的(de)吸(xi)附作用(yong)使制(zhi)(zhi)冷(leng)(leng)劑(ji)蒸發(fa)而(er)制(zhi)(zhi)冷(leng)(leng)。常用(yong)的(de)有氨——水吸(xi)收式制(zhi)(zhi)冷(leng)(leng)機和溴化鋰——水吸(xi)收式制(zhi)(zhi)冷(leng)(leng)機,用(yong)熱源作為動力(li),消耗(hao)電(dian)力(li)少,運轉(zhuan)平穩,易損件少,能(neng)量調節范(fan)圍大,是一種新發(fa)展起(qi)來(lai)的(de)制(zhi)(zhi)冷(leng)(leng)機品種。
制冷(leng)機(ji)(ji)容量應該與(yu)庫房的(de)熱負荷相匹配。這點(dian)可以通(tong)過合理(li)的(de)配機(ji)(ji)和利用能量調節裝(zhuang)(zhuang)置(zhi)(zhi)等方法達到。當然,最主要是要有比較好(hao)的(de)冷(leng)庫安(an)裝(zhuang)(zhuang)節能措施。如果庫房的(de)熱負荷不變(bian),而壓(ya)縮機(ji)(ji)的(de)容量大時,就(jiu)會(hui)使系統(tong)蒸(zheng)發溫(wen)度(du)降低(di),或使壓(ya)縮機(ji)(ji)倒霉(mei),這是很不好(hao)調整的(de)制冷(leng)系統(tong),制冷(leng)裝(zhuang)(zhuang)置(zhi)(zhi)穩定性也差。反之,如果制冷(leng)機(ji)(ji)容量減小時,由于機(ji)(ji)器未能及時吸回蒸(zheng)發器內形(xing)成的(de)制冷(leng)劑氣體(ti),又會(hui)使蒸(zheng)發器溫(wen)度(du)升高、庫房降溫(wen)困難。
當庫房熱負荷及制(zhi)冷機容量(liang)(liang)不變時,如(ru)蒸(zheng)(zheng)發器蒸(zheng)(zheng)發管(guan)內表面有(you)(you)油膜或管(guan)外表面有(you)(you)霜層,也會影響冷卻效果(guo),庫房降溫困(kun)難。蒸(zheng)(zheng)發溫度較設計要求過(guo)高(gao)或過(guo)低(di)(di)都是不正確(que)的,過(guo)高(gao)不能滿足食(shi)品加(jia)工(gong)工(gong)藝(yi)要求,過(guo)低(di)(di)使制(zhi)冷機的能量(liang)(liang)指(zhi)標與運轉經濟性變壞。具體(ti)表現如(ru)下(xia):
①蒸(zheng)(zheng)發溫度降低,使制(zhi)冷(leng)(leng)機制(zhi)冷(leng)(leng)量(liang)減少,這是(shi)由(you)于蒸(zheng)(zheng)發器(qi)內的(de)氣體比容增(zeng)大,單位容積(ji)制(zhi)冷(leng)(leng)量(liang)減少,因而,制(zhi)冷(leng)(leng)機每小時(shi)循(xun)環的(de)制(zhi)冷(leng)(leng)劑質量(liang)液(ye)減少;
②蒸發溫度(du)降低,壓(ya)縮(suo)每(mei)公斤(jin)氣體所消耗的功能(neng)增加。
離心式(shi)制冷(leng)(leng)機節(jie)能方法1.制冷(leng)(leng)機節(jie)能原則:提(ti)高蒸發溫度,降(jiang)低冷(leng)(leng)凝(ning)溫度。在滿足設備安(an)全和生(sheng)產需求的(de)前提(ti)下,盡量提(ti)高蒸發溫度和降(jiang)低冷(leng)(leng)凝(ning)溫度。為此加大了(le)冷(leng)(leng)卻塔的(de)改(gai)造(zao),以保證冷(leng)(leng)卻水效能。
2.防止和減少管(guan)道(dao)結垢(gou)以提高冷(leng)凝器(qi)(qi)(qi)和蒸(zheng)(zheng)發(fa)器(qi)(qi)(qi)的換熱(re)效(xiao)率補充水(shui)如(ru)果水(shui)處(chu)理做的不好,碳(tan)酸(suan)(suan)氫鈣(gai)(gai)和碳(tan)酸(suan)(suan)氫鎂受熱(re)產(chan)生的碳(tan)酸(suan)(suan)鈣(gai)(gai)和碳(tan)酸(suan)(suan)鎂會(hui)沉積在管(guan)道(dao)上。使導熱(re)性能(neng)下降,影響(xiang)冷(leng)凝器(qi)(qi)(qi)和蒸(zheng)(zheng)發(fa)器(qi)(qi)(qi)的換熱(re)效(xiao)率,并(bing)使設備運(yun)行電費大幅度上升。此時除了(le)采(cai)用(yong)水(shui)處(chu)理技(ji)術外,還(huan)可以利用(yong)管(guan)道(dao)定期自(zi)動(dong)清洗設備進行管(guan)道(dao)清洗。
3.調整制冷機設(she)備合(he)理的運行負載(zai)
在(zai)保證設備安全運(yun)行(xing)的(de)(de)情(qing)況下,制(zhi)冷主機運(yun)行(xing)在(zai)70%-80%負載比運(yun)行(xing)在(zai)100%負載時(shi),單位冷量的(de)(de)功耗更(geng)小。運(yun)用此方(fang)式開(kai)機要(yao)結合(he)水泵、冷卻(que)塔的(de)(de)運(yun)行(xing)情(qing)況綜合(he)考慮。
4.采用制冷(leng)機(ji)(ji)變頻裝置,調節(jie)(jie)離(li)心(xin)(xin)制冷(leng)機(ji)(ji)壓(ya)縮機(ji)(ji)的(de)轉速(su)(su)低壓(ya)的(de)冷(leng)媒經過離(li)心(xin)(xin)機(ji)(ji)后,壓(ya)力升(sheng)高(gao)。離(li)心(xin)(xin)機(ji)(ji)的(de)轉速(su)(su)越大(da),壓(ya)力升(sheng)得越高(gao)。在實際(ji)運行中(zhong),設備大(da)多是在非滿負(fu)荷(he)運行。固定轉速(su)(su)的(de)離(li)心(xin)(xin)機(ji)(ji)在設備小負(fu)荷(he)運行時(shi),造成能源浪費。而變頻離(li)心(xin)(xin)制冷(leng)機(ji)(ji)可以依據負(fu)荷(he)的(de)變化,自動調節(jie)(jie)壓(ya)縮機(ji)(ji)轉速(su)(su),節(jie)(jie)能空(kong)間比較大(da)。
1、加油
1)當油(you)位(wei)低于視鏡1/4時(shi),應及時(shi)補充潤滑油(you)
2)將加(jia)油管(guan)一端連接壓縮機進(jin)氣端的加(jia)油閥,微開加(jia)油閥,利用系統中的壓力將加(jia)油管(guan)內的空氣排(pai)出,另一端插入油桶內
3)適(shi)當(dang)關小(xiao)系(xi)統(tong)制冷劑(ji)供液閥,并調整吸氣低壓報警設置,以免因壓力過低而(er)停車
4)當吸氣壓力低于大氣壓時(shi),打(da)開加油閥,油會(hui)自(zi)動進入壓縮(suo)機內
5)當油(you)(you)位超過視鏡5/6時,應停(ting)止加(jia)油(you)(you)操作:先關加(jia)油(you)(you)閥(fa),再打開系統供液(ye)閥(fa),恢復正(zheng)常
2、補充制冷劑
1)當判斷系統(tong)缺(que)液時,應及時給系統(tong)加(jia)氟
2)將加(jia)氟(fu)管一端(duan)與系統加(jia)氟(fu)口相連,另一端(duan)與氟(fu)瓶相連,通過加(jia)氟(fu)軟管趕出管內的(de)空氣
3)先打(da)開氟瓶的(de)閥門,確認無泄(xie)漏后再開加氟口處的(de)閥門
4)R23系統(tong)應將瓶口朝(chao)上,而R404A系統(tong)應將瓶口朝(chao)下,以保證(zheng)迅速加氟(fu)
5)加氟結束時(shi),應先關閉(bi)氟瓶的閥(fa)門(men),再(zai)關加氟口的閥(fa)門(men)
6)制冷劑添(tian)加(jia)一次不(bu)可(ke)過(guo)多,以免排氣(qi)壓(ya)力過(guo)高。如一次添(tian)加(jia)不(bu)足,可(ke)重(zhong)復進行
7)判斷系統(tong)液(ye)位正(zheng)常的依據(ju)是,R23系統(tong)為停(ting)車均壓(ya)后的壓(ya)力值在6~8bar之間(jian),R404A系統(tong)運行中(zhong)冷凝器的液(ye)位在視鏡的1/5~2/5處
3、放空氣
1)當系統壓(ya)力(li)明顯高于(yu)相應溫度下(xia)的飽和壓(ya)力(li)時,應考慮(lv)放空(kong)氣
2)由(you)于空(kong)氣(qi)只(zhi)集中在高壓(ya)部(bu)分,所以應通過冷凝器的排空(kong)閥操(cao)作
3)高(gao)溫(wen)系統應在停車時進行,低(di)溫(wen)系統最好在運行時進行
4)具體操作要(yao)精(jing)心,絲堵不要(yao)開啟過大,也不要(yao)遠離現場
5)空氣操作(zuo)應(ying)分幾次進行,不可一次放氣太多,以免放出(chu)過量的(de)制冷劑
制(zhi)冷(leng)機(ji)等換熱(re)器(qi)(qi)在制(zhi)作時(shi),管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)與(yu)列管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)焊接(jie)一(yi)般采用手工(gong)電(dian)(dian)弧焊,焊縫形狀存在不(bu)同程度(du)的(de)(de)(de)(de)缺陷,如(ru)凹(ao)陷、氣孔(kong)(kong)、夾渣等,焊縫應(ying)力(li)的(de)(de)(de)(de)分布也不(bu)均(jun)勻。使用時(shi)管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)部(bu)分一(yi)般與(yu)工(gong)業(ye)(ye)冷(leng)卻(que)水(shui)接(jie)觸,而工(gong)業(ye)(ye)冷(leng)卻(que)水(shui)中的(de)(de)(de)(de)雜(za)質、鹽(yan)類(lei)、氣體、微(wei)生(sheng)物都會(hui)(hui)構成(cheng)對管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)和(he)(he)(he)焊縫的(de)(de)(de)(de)腐(fu)蝕(shi)(shi)。這(zhe)就(jiu)是(shi)(shi)(shi)我們常說的(de)(de)(de)(de)電(dian)(dian)化(hua)(hua)學(xue)腐(fu)蝕(shi)(shi)。研究表(biao)明,工(gong)業(ye)(ye)水(shui)無論是(shi)(shi)(shi)淡水(shui)還(huan)是(shi)(shi)(shi)海(hai)水(shui),都會(hui)(hui)有各(ge)(ge)種(zhong)離子和(he)(he)(he)溶解的(de)(de)(de)(de)氧(yang)氣,其(qi)中氯離子和(he)(he)(he)氧(yang)的(de)(de)(de)(de)濃度(du)變化(hua)(hua),對金屬的(de)(de)(de)(de)腐(fu)蝕(shi)(shi)形狀起重要作用。另(ling)外,金屬結構的(de)(de)(de)(de)復雜(za)程度(du)也會(hui)(hui)影響腐(fu)蝕(shi)(shi)形態。因此(ci),管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)與(yu)列管(guan)(guan)(guan)(guan)焊縫的(de)(de)(de)(de)腐(fu)蝕(shi)(shi)以(yi)孔(kong)(kong)蝕(shi)(shi)和(he)(he)(he)縫隙腐(fu)蝕(shi)(shi)為主。從外觀看,管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)表(biao)面會(hui)(hui)有許多腐(fu)蝕(shi)(shi)產(chan)物和(he)(he)(he)積沉(chen)物,分布著大(da)小不(bu)等的(de)(de)(de)(de)凹(ao)坑(keng)。以(yi)海(hai)水(shui)為介質時(shi),還(huan)會(hui)(hui)產(chan)生(sheng)電(dian)(dian)偶腐(fu)蝕(shi)(shi)。化(hua)(hua)學(xue)腐(fu)蝕(shi)(shi)就(jiu)是(shi)(shi)(shi)介質的(de)(de)(de)(de)腐(fu)蝕(shi)(shi),換熱(re)器(qi)(qi)管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)接(jie)觸各(ge)(ge)種(zhong)各(ge)(ge)樣的(de)(de)(de)(de)化(hua)(hua)學(xue)介質,就(jiu)會(hui)(hui)受到化(hua)(hua)學(xue)介質的(de)(de)(de)(de)腐(fu)蝕(shi)(shi)。另(ling)外,換熱(re)器(qi)(qi)管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)還(huan)會(hui)(hui)與(yu)換熱(re)管(guan)(guan)(guan)(guan)之間產(chan)生(sheng)一(yi)定的(de)(de)(de)(de)雙(shuang)金屬腐(fu)蝕(shi)(shi)。一(yi)些管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)還(huan)長期處于(yu)腐(fu)蝕(shi)(shi)介質的(de)(de)(de)(de)沖蝕(shi)(shi)中。尤其(qi)是(shi)(shi)(shi)固定管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)換熱(re)器(qi)(qi),還(huan)有溫差應(ying)力(li),管(guan)(guan)(guan)(guan)板(ban)(ban)(ban)(ban)(ban)(ban)與(yu)換熱(re)管(guan)(guan)(guan)(guan)聯接(jie)處極(ji)易泄漏,導致(zhi)換熱(re)器(qi)(qi)失效。
綜上所述,影響制冷機腐蝕的主(zhu)要因素有:
(1)介質成分(fen)和濃(nong)(nong)度(du):濃(nong)(nong)度(du)的(de)影響(xiang)不(bu)一,例如在鹽(yan)酸中,一般濃(nong)(nong)度(du)越(yue)大腐蝕越(yue)嚴重(zhong)(zhong)。碳鋼和不(bu)銹(xiu)鋼在濃(nong)(nong)度(du)為50%左右(you)的(de)硫酸中腐蝕最(zui)嚴重(zhong)(zhong),而當濃(nong)(nong)度(du)增加到60%以(yi)上時,腐蝕反而急(ji)劇(ju)下降;
(2)雜質:有害雜質包括氯離(li)子(zi)(zi)(zi)、硫離(li)子(zi)(zi)(zi)、氰離(li)子(zi)(zi)(zi)、氨離(li)子(zi)(zi)(zi)等,這些(xie)雜質在某些(xie)情況下會引起嚴重腐蝕(shi);
(3)溫度(du):腐蝕是一種化學反應(ying),溫度(du)每提升(sheng)10℃,腐蝕速度(du)約(yue)增(zeng)加1~3倍,但也(ye)有例外;
(4)ph值:一般ph值越小,金(jin)屬的腐(fu)蝕越大;
(5)流速:多數(shu)情況下流速越(yue)大(da),腐(fu)蝕(shi)也越(yue)大(da)。
可(ke)采用(yong)高(gao)分子復(fu)合材料對(dui)制冷(leng)機管板進行防腐保(bao)護,其中(zhong)應(ying)有(you)比較成熟的(de)(de)有(you)美(mei)嘉華技術產品,其具有(you)優異的(de)(de)粘著性(xing)(xing)能(neng)(neng)(neng)及(ji)抗(kang)溫、抗(kang)化學腐蝕性(xing)(xing)能(neng)(neng)(neng),材料為100%固體,沒有(you)可(ke)揮發性(xing)(xing)物質,在封(feng)閉的(de)(de)環境里可(ke)以(yi)安全(quan)使用(yong)而不(bu)會收(shou)縮(suo),特別是材料良(liang)好(hao)的(de)(de)隔離(li)雙金屬腐蝕和出色的(de)(de)耐沖刷性(xing)(xing)能(neng)(neng)(neng),優異的(de)(de)防腐性(xing)(xing)能(neng)(neng)(neng),從(cong)根本上杜絕了修復(fu)部位(wei)的(de)(de)腐蝕滲漏,可(ke)以(yi)為部件提供一(yi)個長久的(de)(de)保(bao)護涂層。
操作工藝:
1、工具及設備:噴砂設備、保護(hu)用的帆布(bu)或塑料布(bu)、軟木塞、酒精或丙酮、刮刀、螺旋器、垃圾袋、手(shou)電鉆、工作電源、橡(xiang)膠手(shou)套、安(an)全帽(mao)、防(fang)護(hu)眼鏡、擦布(bu)、毛刷(shua)。
2、步驟
第一步(bu):打開制冷機冷凝(ning)器端蓋
用(yong)吹(chui)風機和鼓風機吹(chui)干管(guan)(guan)子表面和里面的水(shui),然(ran)后用(yong)軟木塞(sai)塞(sai)住管(guan)(guan)口并遮擋住翻邊(bian),以確(que)保(bao)噴砂處理時不損傷(shang)管(guan)(guan)口。
第二步(bu):噴砂(sha)(sha)(sha)(sha)處理(li):在(zai)噴砂(sha)(sha)(sha)(sha)處理(li)時用帆布和其它等遮擋一(yi)下,以(yi)免噴出的(de)砂(sha)(sha)(sha)(sha)粒弄臟(zang)其它設備。噴砂(sha)(sha)(sha)(sha)時使(shi)用石英砂(sha)(sha)(sha)(sha)或金剛砂(sha)(sha)(sha)(sha),它可以(yi)產(chan)生(sheng)4密耳的(de)表面而不(bu)會產(chan)生(sheng)更多的(de)灰(hui)塵,要一(yi)直打出基材金屬本色(se)。噴砂(sha)(sha)(sha)(sha)完畢后將軟木(mu)塞取出。
第三步:溶(rong)液清洗:用丙酮把金屬(shu)表(biao)面(mian)的雜質(zhi)及油(you)污清洗干凈。
第(di)四(si)步:涂抹材(cai)料(liao):先用美嘉(jia)華高分(fen)子(zi)修(xiu)(xiu)復材(cai)料(liao)金(jin)屬修(xiu)(xiu)復材(cai)料(liao)把冷凝(ning)器管板(ban)內壁有(you)坑的(de)部(bu)位(wei)進行填(tian)平(ping),以免在(zai)工作時水產(chan)生(sheng)渦(wo)流(liu),直至(zhi)達到要(yao)求平(ping)面為準。然后(hou)把高分(fen)子(zi)流(liu)體(ti)保護材(cai)料(liao)均(jun)勻涂至(zhi)整個被(bei)修(xiu)(xiu)復面。尤(you)其注意(yi)面板(ban)與管子(zi)的(de)接合處,以達到密封、堵漏的(de)目(mu)的(de)。
第五步(bu):固化(hua)(hua)(hua):按照材料的固化(hua)(hua)(hua)要(yao)求進行固化(hua)(hua)(hua),固化(hua)(hua)(hua)完畢后即可投(tou)入(ru)生產運(yun)行。