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)降低了(le)空氣加熱(re)(re)器(qi)內電(dian)(dian)熱(re)(re)元件表面溫度,不僅有利于(yu)延長空氣加熱(re)(re)器(qi)電(dian)(dian)熱(re)(re)元件的使(shi)(shi)用壽命,而(er)且使(shi)(shi)得(de)空氣電(dian)(dian)加熱(re)(re)器(qi)散熱(re)(re)損失(shi)減小(xiao),因(yin)而(er)空氣換熱(re)(re)器(qi)的效率提(ti)高了(le),但速度如果過大,使(shi)(shi)得(de)壓力損失(shi)陡增,這將(jiang)不利于(yu)加熱(re)(re)效率的提(ti)高。
2.若其它條件(jian)不變,改變表(biao)(biao)面(mian)(mian)負(fu)(fu)荷(he),空(kong)氣加(jia)熱(re)(re)器中電(dian)熱(re)(re)元(yuan)(yuan)件(jian)的(de)(de)(de)壁溫(wen)(wen)將(jiang)呈直線變化,如(ru)果(guo)表(biao)(biao)面(mian)(mian)負(fu)(fu)荷(he)增(zeng)大(da),電(dian)熱(re)(re)元(yuan)(yuan)件(jian)的(de)(de)(de)壁溫(wen)(wen)將(jiang)增(zeng)大(da),這將(jiang)降低(di)空(kong)氣加(jia)熱(re)(re)器中電(dian)熱(re)(re)元(yuan)(yuan)件(jian)的(de)(de)(de)使用壽命,但是如(ru)果(guo)表(biao)(biao)面(mian)(mian)負(fu)(fu)荷(he)過小,壁溫(wen)(wen)過低(di),空(kong)氣加(jia)熱(re)(re)器換熱(re)(re)器的(de)(de)(de)效率又降低(di)了,所以(yi)空(kong)氣加(jia)熱(re)(re)器中電(dian)熱(re)(re)元(yuan)(yuan)件(jian)的(de)(de)(de)表(biao)(biao)面(mian)(mian)負(fu)(fu)荷(he)的(de)(de)(de)選擇比較重要。
3.空氣加(jia)熱(re)器(qi)中(zhong)(zhong)空氣終溫T2提(ti)高(gao)時(shi),由于空氣粘性增(zeng)加(jia),氣體雷諾數減小,使(shi)得(de)對流換熱(re)強度(du)降低(di),空氣加(jia)熱(re)器(qi)中(zhong)(zhong)電(dian)(dian)熱(re)元件(jian)(jian)的表面溫度(du)同時(shi)上(shang)升(sheng),紅外碳硫分析儀使(shi)得(de)散熱(re)損失增(zeng)加(jia),從而降低(di)換熱(re)器(qi)的效(xiao)率(lv)。當T2提(ti)高(gao)過(guo)大時(shi),電(dian)(dian)熱(re)元件(jian)(jian)表面的溫度(du)亦會大大升(sheng)高(gao),致使(shi)一(yi)般電(dian)(dian)熱(re)元件(jian)(jian)無法承受,故T2的增(zeng)加(jia)通常受到空氣加(jia)熱(re)器(qi)中(zhong)(zhong)電(dian)(dian)熱(re)元件(jian)(jian)材料耐熱(re)性能的限制。