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熱(re),而降低了(le)空氣加(jia)(jia)熱(re)器(qi)內電(dian)熱(re)元(yuan)件表(biao)面溫度(du),不僅有利于延(yan)長空氣加(jia)(jia)熱(re)器(qi)電(dian)熱(re)元(yuan)件的使用(yong)壽(shou)命,而且使得空氣電(dian)加(jia)(jia)熱(re)器(qi)散熱(re)損失(shi)減小,因而空氣換熱(re)器(qi)的效率提高(gao)了(le),但速(su)度(du)如果(guo)過大(da),使得壓(ya)力(li)損失(shi)陡增,這將不利于加(jia)(jia)熱(re)效率的提高(gao)。
2.若其(qi)它條件不變,改變表面(mian)負荷(he),空(kong)氣加熱(re)(re)(re)器中(zhong)電(dian)熱(re)(re)(re)元件的壁(bi)溫將(jiang)呈直線變化,如(ru)果(guo)表面(mian)負荷(he)增(zeng)大,電(dian)熱(re)(re)(re)元件的壁(bi)溫將(jiang)增(zeng)大,這將(jiang)降低(di)(di)空(kong)氣加熱(re)(re)(re)器中(zhong)電(dian)熱(re)(re)(re)元件的使用壽命,但是(shi)如(ru)果(guo)表面(mian)負荷(he)過(guo)小,壁(bi)溫過(guo)低(di)(di),空(kong)氣加熱(re)(re)(re)器換熱(re)(re)(re)器的效率又(you)降低(di)(di)了,所以空(kong)氣加熱(re)(re)(re)器中(zhong)電(dian)熱(re)(re)(re)元件的表面(mian)負荷(he)的選(xuan)擇比較(jiao)重要。
3.空(kong)氣加(jia)(jia)(jia)(jia)熱(re)(re)(re)器(qi)中空(kong)氣終(zhong)溫T2提(ti)(ti)高時(shi),由(you)于空(kong)氣粘性增加(jia)(jia)(jia)(jia),氣體雷諾數減(jian)小,使得對流換熱(re)(re)(re)強(qiang)度降低(di),空(kong)氣加(jia)(jia)(jia)(jia)熱(re)(re)(re)器(qi)中電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的表(biao)(biao)面溫度同時(shi)上(shang)升,紅外碳硫(liu)分析(xi)儀使得散熱(re)(re)(re)損失增加(jia)(jia)(jia)(jia),從而降低(di)換熱(re)(re)(re)器(qi)的效(xiao)率。當(dang)T2提(ti)(ti)高過大(da)時(shi),電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)表(biao)(biao)面的溫度亦(yi)會大(da)大(da)升高,致使一(yi)般(ban)電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)無法承受,故T2的增加(jia)(jia)(jia)(jia)通常受到空(kong)氣加(jia)(jia)(jia)(jia)熱(re)(re)(re)器(qi)中電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)材料耐熱(re)(re)(re)性能的限制。