制冷機將具有較低溫度的被冷卻物體的熱量轉移給環境介質從而獲得冷量的機器。從較低溫度物體轉移的熱量習慣上稱為冷量。制冷機內參與熱力過程變化（能量轉換和熱量轉移）的工質稱為制冷劑。制(zhi)(zhi)冷(leng)(leng)(leng)(leng)的溫度(du)范圍通(tong)常在120K以(yi)上，120K以(yi)下屬深低(di)溫技術范圍。廣西制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)廣泛應用(yong)于(yu)工(gong)農(nong)業生(sheng)(sheng)產和(he)日常生(sheng)(sheng)活中。 制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)的主要性(xing)能指標有工(gong)作(zuo)溫度(du)（對蒸(zheng)氣(qi)壓縮(suo)式制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)為蒸(zheng)發溫度(du)和(he)冷(leng)(leng)(leng)(leng)凝溫度(du)，對氣(qi)體壓縮(suo)式制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)和(he)半(ban)導體制(zhi)(zhi)冷(leng)(leng)(leng)(leng)器為被冷(leng)(leng)(leng)(leng)物體的溫度(du)和(he)冷(leng)(leng)(leng)(leng)卻介質(zhi)的溫度(du)），制(zhi)(zhi)冷(leng)(leng)(leng)(leng)量(liang)(liang)（制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)單位(wei)時間內從被冷(leng)(leng)(leng)(leng)卻物體移去(qu)的熱量(liang)(liang)）、功率(lv)或耗熱量(liang)(liang)、制(zhi)(zhi)冷(leng)(leng)(leng)(leng)系數(shu)（衡(heng)量(liang)(liang)壓縮(suo)式制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)經濟(ji)性(xing)的指標，指消耗單位(wei)功所能得(de)到的冷(leng)(leng)(leng)(leng)量(liang)(liang)）以(yi)及(ji)熱力系數(shu)（衡(heng)量(liang)(liang)吸收(shou)式和(he)蒸(zheng)汽(qi)噴(pen)射式制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)經濟(ji)性(xing)的指標，指消耗單位(wei)熱量(liang)(liang)所能得(de)到的冷(leng)(leng)(leng)(leng)量(liang)(liang)）等。現代制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)以(yi)蒸(zheng)氣(qi)壓縮(suo)式制(zhi)(zhi)冷(leng)(leng)(leng)(leng)機(ji)(ji)應用(yong)最廣。