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)(re),而降低了空氣加熱(re)(re)器(qi)(qi)內電(dian)熱(re)(re)元件表面溫度(du),不(bu)(bu)僅有(you)利(li)(li)于延長空氣加熱(re)(re)器(qi)(qi)電(dian)熱(re)(re)元件的使(shi)用(yong)壽命,而且(qie)使(shi)得空氣電(dian)加熱(re)(re)器(qi)(qi)散(san)熱(re)(re)損失減(jian)小,因而空氣換熱(re)(re)器(qi)(qi)的效(xiao)(xiao)率提(ti)(ti)高了,但速度(du)如(ru)果(guo)過大,使(shi)得壓力損失陡增,這(zhe)將不(bu)(bu)利(li)(li)于加熱(re)(re)效(xiao)(xiao)率的提(ti)(ti)高。
2.若(ruo)其它(ta)條件(jian)(jian)不變,改變表(biao)面(mian)負荷,空(kong)(kong)氣(qi)(qi)加(jia)(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)中電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)壁溫(wen)將(jiang)呈直線變化,如(ru)果表(biao)面(mian)負荷增大(da),電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)壁溫(wen)將(jiang)增大(da),這將(jiang)降低空(kong)(kong)氣(qi)(qi)加(jia)(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)中電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)使用壽命(ming),但(dan)是如(ru)果表(biao)面(mian)負荷過小,壁溫(wen)過低,空(kong)(kong)氣(qi)(qi)加(jia)(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)換(huan)熱(re)(re)(re)器(qi)(qi)(qi)的(de)效率又降低了,所以空(kong)(kong)氣(qi)(qi)加(jia)(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)中電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)表(biao)面(mian)負荷的(de)選(xuan)擇比較重要。
3.空氣(qi)加(jia)熱器(qi)中(zhong)空氣(qi)終溫(wen)T2提(ti)高時,由于空氣(qi)粘(zhan)性增(zeng)加(jia),氣(qi)體雷(lei)諾數減小(xiao),使(shi)得(de)對流換熱強度(du)降低,空氣(qi)加(jia)熱器(qi)中(zhong)電(dian)熱元件的(de)表面溫(wen)度(du)同時上升,紅外碳硫分析儀使(shi)得(de)散熱損失增(zeng)加(jia),從而降低換熱器(qi)的(de)效率。當T2提(ti)高過(guo)大(da)時,電(dian)熱元件表面的(de)溫(wen)度(du)亦會大(da)大(da)升高,致使(shi)一般電(dian)熱元件無法承(cheng)受,故T2的(de)增(zeng)加(jia)通常受到空氣(qi)加(jia)熱器(qi)中(zhong)電(dian)熱元件材料耐(nai)熱性能的(de)限制。