制冷劑

制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)中(zhong)(zhong)完成熱力(li)(li)循環的(de)(de)工(gong)(gong)(gong)質(zhi)。它在低(di)溫(wen)下吸取被冷(leng)(leng)(leng)(leng)卻(que)物(wu)體的(de)(de)熱量(liang)，然后在較高(gao)溫(wen)度(du)下轉移給冷(leng)(leng)(leng)(leng)卻(que)水(shui)(shui)或空(kong)(kong)氣(qi)。在蒸氣(qi)壓(ya)縮式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)中(zhong)(zhong)，使用(yong)(yong)在常溫(wen)或較低(di)溫(wen)度(du)下能液(ye)化的(de)(de)工(gong)(gong)(gong)質(zhi)為(wei)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)劑(ji)(ji)，如氟利(li)昂(ang)（飽和(he)(he)(he)碳氫(qing)化合(he)物(wu)的(de)(de)氟、氯(lv)、溴衍生物(wu)），共(gong)沸混合(he)工(gong)(gong)(gong)質(zhi)（由兩種氟利(li)昂(ang)按一定(ding)比(bi)例混合(he)而(er)成的(de)(de)共(gong)沸溶(rong)(rong)液(ye)）、碳氫(qing)化合(he)物(wu)（丙(bing)烷(wan)、乙烯等(deng)(deng)）、氨(an)(an)等(deng)(deng)；在氣(qi)體壓(ya)縮式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)中(zhong)(zhong)，使用(yong)(yong)氣(qi)體制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)劑(ji)(ji)，如空(kong)(kong)氣(qi)、氫(qing)氣(qi)、氦氣(qi)等(deng)(deng)，這些氣(qi)體在制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)循環中(zhong)(zhong)始終為(wei)氣(qi)態；在吸收(shou)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)中(zhong)(zhong)，使用(yong)(yong)由吸收(shou)劑(ji)(ji)和(he)(he)(he)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)劑(ji)(ji)組(zu)成的(de)(de)二(er)元溶(rong)(rong)液(ye)作為(wei)工(gong)(gong)(gong)質(zhi)，如氨(an)(an)和(he)(he)(he)水(shui)(shui)、溴化鋰 （分子式(shi)(shi)(shi)：LiBr。白色立方(fang)晶(jing)系(xi)(xi)結晶(jing)或粒狀粉末(mo)，易(yi)溶(rong)(rong)于水(shui)(shui)）和(he)(he)(he)水(shui)(shui)等(deng)(deng)；蒸汽噴射(she)式(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)用(yong)(yong)水(shui)(shui)作為(wei)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)劑(ji)(ji)。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)劑(ji)(ji)的(de)(de)主要技術(shu)指標(biao)有飽和(he)(he)(he)蒸氣(qi)壓(ya)強、比(bi)熱、粘度(du)、導熱系(xi)(xi)數、表面(mian)張力(li)(li)等(deng)(deng)。1960年以后，人(ren)們(men)對(dui)非共(gong)沸混合(he)工(gong)(gong)(gong)質(zhi)的(de)(de)應用(yong)(yong)進行(xing)了大量(liang)的(de)(de)試驗研究，并已將(jiang)其用(yong)(yong)于天然氣(qi)的(de)(de)液(ye)化和(he)(he)(he)分離等(deng)(deng)方(fang)面(mian)。應用(yong)(yong)非共(gong)沸混合(he)工(gong)(gong)(gong)質(zhi)單級壓(ya)縮可得到(dao)很低(di)的(de)(de)蒸發溫(wen)度(du)，且(qie)可增(zeng)加制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)量(liang)，減少功耗。 它的(de)(de)性(xing)質(zhi)直接關系(xi)(xi)到(dao)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)裝置(zhi)的(de)(de)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)效果(guo)、經濟性(xing)及運行(xing)管理，因(yin)而(er)對(dui)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)冷(leng)(leng)(leng)(leng)劑(ji)(ji)性(xing)質(zhi)要求的(de)(de)了解是不容忽視的(de)(de)。