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,而降低了空(kong)氣(qi)加熱器內電(dian)熱元件(jian)表面(mian)溫(wen)度(du),不(bu)僅有利于延(yan)長空(kong)氣(qi)加熱器電(dian)熱元件(jian)的使用壽命,而且使得(de)空(kong)氣(qi)電(dian)加熱器散(san)熱損失減小(xiao),因而空(kong)氣(qi)換熱器的效(xiao)(xiao)率提(ti)高(gao)了,但速度(du)如果過大,使得(de)壓(ya)力損失陡(dou)增,這(zhe)將不(bu)利于加熱效(xiao)(xiao)率的提(ti)高(gao)。
2.若(ruo)其(qi)它條件(jian)不變,改變表(biao)(biao)面(mian)負荷(he),空氣(qi)(qi)加(jia)熱器(qi)中(zhong)電熱元件(jian)的(de)(de)壁溫將(jiang)呈直線變化,如(ru)果表(biao)(biao)面(mian)負荷(he)增(zeng)大(da),電熱元件(jian)的(de)(de)壁溫將(jiang)增(zeng)大(da),這將(jiang)降(jiang)低(di)空氣(qi)(qi)加(jia)熱器(qi)中(zhong)電熱元件(jian)的(de)(de)使用壽命,但是(shi)如(ru)果表(biao)(biao)面(mian)負荷(he)過小(xiao),壁溫過低(di),空氣(qi)(qi)加(jia)熱器(qi)換熱器(qi)的(de)(de)效率又降(jiang)低(di)了,所以空氣(qi)(qi)加(jia)熱器(qi)中(zhong)電熱元件(jian)的(de)(de)表(biao)(biao)面(mian)負荷(he)的(de)(de)選(xuan)擇(ze)比較重要。
3.空(kong)(kong)(kong)氣(qi)加熱(re)(re)器(qi)中(zhong)空(kong)(kong)(kong)氣(qi)終溫T2提(ti)高時,由于空(kong)(kong)(kong)氣(qi)粘性增(zeng)加,氣(qi)體雷諾數減(jian)小,使(shi)得(de)對流(liu)換(huan)熱(re)(re)強度降(jiang)低,空(kong)(kong)(kong)氣(qi)加熱(re)(re)器(qi)中(zhong)電熱(re)(re)元件(jian)(jian)的表(biao)面溫度同時上升(sheng),紅(hong)外碳(tan)硫(liu)分析(xi)儀使(shi)得(de)散熱(re)(re)損失增(zeng)加,從而(er)降(jiang)低換(huan)熱(re)(re)器(qi)的效率(lv)。當T2提(ti)高過大時,電熱(re)(re)元件(jian)(jian)表(biao)面的溫度亦會(hui)大大升(sheng)高,致使(shi)一般(ban)電熱(re)(re)元件(jian)(jian)無法承受,故(gu)T2的增(zeng)加通常受到空(kong)(kong)(kong)氣(qi)加熱(re)(re)器(qi)中(zhong)電熱(re)(re)元件(jian)(jian)材料耐熱(re)(re)性能的限制。