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,而(er)降低了空(kong)氣加熱器內電熱元件表面溫度(du),不(bu)僅有利(li)于延(yan)長空(kong)氣加熱器電熱元件的使(shi)用壽命,而(er)且使(shi)得空(kong)氣電加熱器散熱損(sun)失(shi)減小,因而(er)空(kong)氣換熱器的效率(lv)提(ti)高了,但速度(du)如果過大,使(shi)得壓力損(sun)失(shi)陡增,這將不(bu)利(li)于加熱效率(lv)的提(ti)高。
2.若其它條(tiao)件(jian)(jian)(jian)不變,改(gai)變表(biao)面(mian)(mian)負荷(he),空氣加熱(re)器(qi)中(zhong)電熱(re)元件(jian)(jian)(jian)的(de)壁溫(wen)將(jiang)呈直線變化,如(ru)果表(biao)面(mian)(mian)負荷(he)增大(da),電熱(re)元件(jian)(jian)(jian)的(de)壁溫(wen)將(jiang)增大(da),這將(jiang)降低空氣加熱(re)器(qi)中(zhong)電熱(re)元件(jian)(jian)(jian)的(de)使(shi)用壽命,但是如(ru)果表(biao)面(mian)(mian)負荷(he)過小,壁溫(wen)過低,空氣加熱(re)器(qi)換熱(re)器(qi)的(de)效率又降低了,所以空氣加熱(re)器(qi)中(zhong)電熱(re)元件(jian)(jian)(jian)的(de)表(biao)面(mian)(mian)負荷(he)的(de)選擇比較重(zhong)要。
3.空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)空(kong)(kong)氣(qi)終溫T2提高(gao)時,由于空(kong)(kong)氣(qi)粘性(xing)增加(jia)(jia),氣(qi)體雷(lei)諾數減小,使得對流換熱(re)(re)(re)強度(du)降低(di)(di),空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元件(jian)的(de)表面溫度(du)同時上升(sheng),紅外碳硫(liu)分析儀使得散熱(re)(re)(re)損失(shi)增加(jia)(jia),從(cong)而降低(di)(di)換熱(re)(re)(re)器(qi)的(de)效率。當T2提高(gao)過大時,電(dian)熱(re)(re)(re)元件(jian)表面的(de)溫度(du)亦會大大升(sheng)高(gao),致使一般電(dian)熱(re)(re)(re)元件(jian)無法承受,故T2的(de)增加(jia)(jia)通常受到空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元件(jian)材(cai)料耐熱(re)(re)(re)性(xing)能的(de)限制。