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(er)降(jiang)低了(le)空(kong)氣加(jia)熱(re)(re)器(qi)內(nei)電(dian)熱(re)(re)元件表面溫度(du),不僅有利于延長(chang)空(kong)氣加(jia)熱(re)(re)器(qi)電(dian)熱(re)(re)元件的(de)使用(yong)壽命,而(er)且使得空(kong)氣電(dian)加(jia)熱(re)(re)器(qi)散(san)熱(re)(re)損失(shi)減小,因而(er)空(kong)氣換熱(re)(re)器(qi)的(de)效率提高了(le),但速度(du)如果過(guo)大,使得壓(ya)力損失(shi)陡增,這將不利于加(jia)熱(re)(re)效率的(de)提高。
2.若其它條件不(bu)變(bian)(bian),改變(bian)(bian)表(biao)面(mian)(mian)負(fu)荷(he)(he),空氣加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)件的壁(bi)溫將(jiang)呈直線變(bian)(bian)化(hua),如果(guo)表(biao)面(mian)(mian)負(fu)荷(he)(he)增大,電(dian)熱(re)(re)(re)元(yuan)件的壁(bi)溫將(jiang)增大,這將(jiang)降低空氣加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)件的使用壽命,但是如果(guo)表(biao)面(mian)(mian)負(fu)荷(he)(he)過(guo)小,壁(bi)溫過(guo)低,空氣加(jia)熱(re)(re)(re)器(qi)換(huan)熱(re)(re)(re)器(qi)的效率又(you)降低了(le),所以空氣加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)件的表(biao)面(mian)(mian)負(fu)荷(he)(he)的選擇比(bi)較重要。
3.空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器中(zhong)空(kong)(kong)氣(qi)終溫(wen)T2提高(gao)時,由于(yu)空(kong)(kong)氣(qi)粘性增加(jia)(jia),氣(qi)體雷諾數減小,使(shi)得(de)對流換熱(re)強度(du)降低(di),空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器中(zhong)電(dian)(dian)熱(re)元(yuan)件的(de)表(biao)面溫(wen)度(du)同時上升(sheng),紅外碳硫分析(xi)儀使(shi)得(de)散熱(re)損失增加(jia)(jia),從(cong)而降低(di)換熱(re)器的(de)效率。當T2提高(gao)過(guo)大(da)(da)時,電(dian)(dian)熱(re)元(yuan)件表(biao)面的(de)溫(wen)度(du)亦會大(da)(da)大(da)(da)升(sheng)高(gao),致(zhi)使(shi)一般電(dian)(dian)熱(re)元(yuan)件無法承受,故T2的(de)增加(jia)(jia)通常受到空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器中(zhong)電(dian)(dian)熱(re)元(yuan)件材料耐熱(re)性能的(de)限(xian)制。