不(bu)管是(shi)家居還是(shi)工(gong)業生產(chan)(chan)，我們常(chang)常(chang)要用管道輸送或(huo)(huo)用儲(chu)罐(guan)貯存一(yi)(yi)些(xie)介(jie)質(zhi)，但隨(sui)著(zhu)(zhu)時間(jian)流(liu)逝或(huo)(huo)氣候溫(wen)度的(de)變化，這(zhe)些(xie)介(jie)質(zhi)通(tong)常(chang)要控制(zhi)在一(yi)(yi)定(ding)溫(wen)度內才能保(bao)持良好的(de)形狀，然當溫(wen)度降低到一(yi)(yi)定(ding)程度，這(zhe)些(xie)介(jie)質(zhi)易結(jie)凍(dong)，不(bu)僅影響了(le)(le)工(gong)業生產(chan)(chan)也破壞了(le)(le)介(jie)質(zhi)品(pin)質(zhi)，因此(ci)需(xu)采取措施，使這(zhe)些(xie)管道中(zhong)(zhong)或(huo)(huo)儲(chu)罐(guan)中(zhong)(zhong)的(de)介(jie)質(zhi)升溫(wen)、保(bao)溫(wen)或(huo)(huo)達(da)到防凍(dong)目的(de)，這(zhe)種措施叫做伴(ban)熱(re)。傳統(tong)上采用的(de)為這(zhe)些(xie)管道或(huo)(huo)儲(chu)罐(guan)中(zhong)(zhong)的(de)介(jie)質(zhi)伴(ban)熱(re)的(de)方法是(shi)蒸(zheng)汽(qi)伴(ban)熱(re)，然而隨(sui)著(zhu)(zhu)科(ke)學(xue)技術的(de)發展，電(dian)伴(ban)熱(re)已經以絕對的(de)優勢大面積取代(dai)了(le)(le)蒸(zheng)汽(qi)伴(ban)熱(re)，成(cheng)為工(gong)業生產(chan)(chan)領域為管道或(huo)(huo)儲(chu)罐(guan)中(zhong)(zhong)的(de)介(jie)質(zhi)保(bao)溫(wen)及防凍(dong)的(de)最好方案(an)。

　　電伴熱的(de)(de)原理是(shi)利(li)用導(dao)(dao)電(dian)(dian)(dian)(dian)(dian)加(jia)熱，不(bu)過(guo)與電(dian)(dian)(dian)(dian)(dian)加(jia)熱不(bu)同的(de)(de)是(shi)，電(dian)(dian)(dian)(dian)(dian)伴熱是(shi)采用導(dao)(dao)電(dian)(dian)(dian)(dian)(dian)的(de)(de)PTC材料與兩根線(xian)芯形(xing)成回路(lu)，接通電(dian)(dian)(dian)(dian)(dian)源后就形(xing)成了回路(lu)，電(dian)(dian)(dian)(dian)(dian)使(shi)導(dao)(dao)電(dian)(dian)(dian)(dian)(dian)材料升(sheng)溫(wen)(wen)(wen)，從而(er)達到(dao)升(sheng)溫(wen)(wen)(wen)的(de)(de)作(zuo)用。目前(qian)廣泛使(shi)用的(de)(de)自控溫(wen)(wen)(wen)電(dian)(dian)(dian)(dian)(dian)伴熱，它的(de)(de)導(dao)(dao)電(dian)(dian)(dian)(dian)(dian)材料的(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)在溫(wen)(wen)(wen)度不(bu)斷上升(sheng)的(de)(de)同時(shi)也(ye)不(bu)斷增加(jia)，當溫(wen)(wen)(wen)度達到(dao)某(mou)一(yi)值后，電(dian)(dian)(dian)(dian)(dian)阻(zu)達到(dao)幾乎(hu)能(neng)(neng)阻(zu)斷電(dian)(dian)(dian)(dian)(dian)流的(de)(de)程度，自然也(ye)就不(bu)能(neng)(neng)在升(sheng)溫(wen)(wen)(wen)，從而(er)達到(dao)限制溫(wen)(wen)(wen)度的(de)(de)作(zuo)用，與傳統的(de)(de)恒(heng)功(gong)率伴熱相比(bi)更節能(neng)(neng)更安全(quan)。電(dian)(dian)(dian)(dian)(dian)伴熱的(de)(de)升(sheng)溫(wen)(wen)(wen)是(shi)需(xu)要一(yi)段時(shi)間的(de)(de)，而(er)電(dian)(dian)(dian)(dian)(dian)加(jia)熱則是(shi)大(da)功(gong)率電(dian)(dian)(dian)(dian)(dian)流通過(guo)線(xian)圈瞬間將物體(ti)加(jia)熱，這在工業生產當中其實是(shi)非(fei)常危險(xian)的(de)(de)。