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)(re)(re),而降低了空氣(qi)加(jia)熱(re)(re)(re)(re)器(qi)內(nei)電(dian)熱(re)(re)(re)(re)元件表面溫(wen)度,不僅有利(li)于延長空氣(qi)加(jia)熱(re)(re)(re)(re)器(qi)電(dian)熱(re)(re)(re)(re)元件的(de)使用(yong)壽命,而且使得(de)空氣(qi)電(dian)加(jia)熱(re)(re)(re)(re)器(qi)散(san)熱(re)(re)(re)(re)損失減小,因而空氣(qi)換熱(re)(re)(re)(re)器(qi)的(de)效(xiao)率(lv)(lv)提高了,但(dan)速(su)度如果(guo)過大,使得(de)壓力(li)損失陡(dou)增,這將不利(li)于加(jia)熱(re)(re)(re)(re)效(xiao)率(lv)(lv)的(de)提高。
2.若其它條件(jian)(jian)不(bu)變,改變表(biao)面負荷(he),空(kong)氣(qi)(qi)加熱(re)(re)器(qi)(qi)中電熱(re)(re)元(yuan)件(jian)(jian)的壁溫將(jiang)呈直線變化,如(ru)果表(biao)面負荷(he)增大(da),電熱(re)(re)元(yuan)件(jian)(jian)的壁溫將(jiang)增大(da),這將(jiang)降低空(kong)氣(qi)(qi)加熱(re)(re)器(qi)(qi)中電熱(re)(re)元(yuan)件(jian)(jian)的使用壽(shou)命(ming),但是(shi)如(ru)果表(biao)面負荷(he)過小,壁溫過低,空(kong)氣(qi)(qi)加熱(re)(re)器(qi)(qi)換熱(re)(re)器(qi)(qi)的效(xiao)率又(you)降低了,所以空(kong)氣(qi)(qi)加熱(re)(re)器(qi)(qi)中電熱(re)(re)元(yuan)件(jian)(jian)的表(biao)面負荷(he)的選(xuan)擇比(bi)較重要(yao)。
3.空(kong)(kong)氣加(jia)(jia)(jia)熱(re)(re)(re)器(qi)(qi)中空(kong)(kong)氣終溫(wen)T2提(ti)高(gao)時,由于空(kong)(kong)氣粘(zhan)性增加(jia)(jia)(jia),氣體雷諾數減(jian)小,使得(de)對流換熱(re)(re)(re)強度降(jiang)低,空(kong)(kong)氣加(jia)(jia)(jia)熱(re)(re)(re)器(qi)(qi)中電(dian)(dian)熱(re)(re)(re)元件的表面(mian)溫(wen)度同時上升(sheng),紅外碳(tan)硫分析(xi)儀(yi)使得(de)散熱(re)(re)(re)損失增加(jia)(jia)(jia),從而降(jiang)低換熱(re)(re)(re)器(qi)(qi)的效率。當T2提(ti)高(gao)過大時,電(dian)(dian)熱(re)(re)(re)元件表面(mian)的溫(wen)度亦會大大升(sheng)高(gao),致使一(yi)般電(dian)(dian)熱(re)(re)(re)元件無法(fa)承受,故T2的增加(jia)(jia)(jia)通常(chang)受到空(kong)(kong)氣加(jia)(jia)(jia)熱(re)(re)(re)器(qi)(qi)中電(dian)(dian)熱(re)(re)(re)元件材(cai)料(liao)耐熱(re)(re)(re)性能的限(xian)制。