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(dui)流換熱(re)(re),而(er)降低了(le)空氣(qi)(qi)(qi)加熱(re)(re)器(qi)內電(dian)熱(re)(re)元(yuan)件表(biao)面溫度(du),不僅有利(li)于延(yan)長(chang)空氣(qi)(qi)(qi)加熱(re)(re)器(qi)電(dian)熱(re)(re)元(yuan)件的使用壽(shou)命(ming),而(er)且(qie)使得(de)空氣(qi)(qi)(qi)電(dian)加熱(re)(re)器(qi)散(san)熱(re)(re)損(sun)失(shi)減小,因(yin)而(er)空氣(qi)(qi)(qi)換熱(re)(re)器(qi)的效率提高(gao)了(le),但速度(du)如果過大,使得(de)壓力(li)損(sun)失(shi)陡增,這將(jiang)不利(li)于加熱(re)(re)效率的提高(gao)。
2.若其它條件不變(bian),改變(bian)表(biao)面負(fu)荷,空(kong)氣(qi)加熱器中(zhong)電熱元件的(de)壁溫(wen)將呈(cheng)直(zhi)線(xian)變(bian)化,如果表(biao)面負(fu)荷增大,電熱元件的(de)壁溫(wen)將增大,這將降低空(kong)氣(qi)加熱器中(zhong)電熱元件的(de)使用(yong)壽命,但(dan)是如果表(biao)面負(fu)荷過小,壁溫(wen)過低,空(kong)氣(qi)加熱器換熱器的(de)效率又降低了,所(suo)以(yi)空(kong)氣(qi)加熱器中(zhong)電熱元件的(de)表(biao)面負(fu)荷的(de)選擇比較重要。
3.空(kong)(kong)(kong)氣加熱(re)(re)器(qi)(qi)中(zhong)(zhong)空(kong)(kong)(kong)氣終(zhong)溫T2提(ti)高時,由于空(kong)(kong)(kong)氣粘性增加,氣體雷諾數減小,使得(de)對(dui)流換熱(re)(re)強(qiang)度降低,空(kong)(kong)(kong)氣加熱(re)(re)器(qi)(qi)中(zhong)(zhong)電熱(re)(re)元件(jian)(jian)(jian)的表(biao)(biao)面(mian)溫度同(tong)時上升,紅外碳硫(liu)分析(xi)儀使得(de)散(san)熱(re)(re)損失增加,從而(er)降低換熱(re)(re)器(qi)(qi)的效率。當T2提(ti)高過(guo)大時,電熱(re)(re)元件(jian)(jian)(jian)表(biao)(biao)面(mian)的溫度亦(yi)會大大升高,致使一般電熱(re)(re)元件(jian)(jian)(jian)無法(fa)承受(shou)(shou),故T2的增加通常受(shou)(shou)到空(kong)(kong)(kong)氣加熱(re)(re)器(qi)(qi)中(zhong)(zhong)電熱(re)(re)元件(jian)(jian)(jian)材料耐熱(re)(re)性能的限(xian)制(zhi)。