空氣電磁加熱器影響因素
1.增大空氣加熱器的氣體入口流速,能夠加強空氣電加熱器對流換(huan)熱(re)(re),而降低了(le)空氣加熱(re)(re)器內電(dian)熱(re)(re)元(yuan)件表面溫(wen)度(du),不僅(jin)有利于(yu)(yu)延長空氣加熱(re)(re)器電(dian)熱(re)(re)元(yuan)件的(de)使(shi)用壽命(ming),而且使(shi)得空氣電(dian)加熱(re)(re)器散(san)熱(re)(re)損失減小,因(yin)而空氣換(huan)熱(re)(re)器的(de)效率提高了(le),但(dan)速度(du)如果過大(da),使(shi)得壓力損失陡增,這(zhe)將不利于(yu)(yu)加熱(re)(re)效率的(de)提高。
2.若其(qi)它條件(jian)(jian)不變(bian),改(gai)變(bian)表面負(fu)(fu)(fu)荷(he),空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)(re)元件(jian)(jian)的壁溫(wen)將呈直(zhi)線變(bian)化,如(ru)果(guo)表面負(fu)(fu)(fu)荷(he)增(zeng)大,電(dian)熱(re)(re)(re)(re)元件(jian)(jian)的壁溫(wen)將增(zeng)大,這將降低(di)空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)(re)元件(jian)(jian)的使(shi)用壽命,但是(shi)如(ru)果(guo)表面負(fu)(fu)(fu)荷(he)過小,壁溫(wen)過低(di),空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器(qi)換(huan)熱(re)(re)(re)(re)器(qi)的效率(lv)又降低(di)了(le),所以空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)(re)元件(jian)(jian)的表面負(fu)(fu)(fu)荷(he)的選擇(ze)比較重要。
3.空(kong)(kong)(kong)氣(qi)加(jia)熱(re)器(qi)中(zhong)空(kong)(kong)(kong)氣(qi)終溫(wen)T2提(ti)高(gao)時(shi),由(you)于空(kong)(kong)(kong)氣(qi)粘性(xing)增加(jia),氣(qi)體雷諾(nuo)數(shu)減小,使得對流換(huan)熱(re)強度(du)降低,空(kong)(kong)(kong)氣(qi)加(jia)熱(re)器(qi)中(zhong)電熱(re)元(yuan)件的(de)(de)(de)表(biao)面(mian)溫(wen)度(du)同時(shi)上升,紅(hong)外(wai)碳硫分析(xi)儀使得散熱(re)損失增加(jia),從而降低換(huan)熱(re)器(qi)的(de)(de)(de)效率。當T2提(ti)高(gao)過大(da)時(shi),電熱(re)元(yuan)件表(biao)面(mian)的(de)(de)(de)溫(wen)度(du)亦會大(da)大(da)升高(gao),致使一般(ban)電熱(re)元(yuan)件無法(fa)承受,故T2的(de)(de)(de)增加(jia)通(tong)常受到(dao)空(kong)(kong)(kong)氣(qi)加(jia)熱(re)器(qi)中(zhong)電熱(re)元(yuan)件材料耐(nai)熱(re)性(xing)能的(de)(de)(de)限制。