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,而降低了空(kong)(kong)氣(qi)加(jia)熱器(qi)內電熱元件表面溫(wen)度,不僅有利于延長空(kong)(kong)氣(qi)加(jia)熱器(qi)電熱元件的使用壽命,而且(qie)使得(de)空(kong)(kong)氣(qi)電加(jia)熱器(qi)散熱損失減小,因而空(kong)(kong)氣(qi)換熱器(qi)的效率(lv)提高了,但速度如果過大,使得(de)壓(ya)力損失陡(dou)增(zeng),這將不利于加(jia)熱效率(lv)的提高。
2.若(ruo)其它條件(jian)(jian)不變,改變表(biao)面負荷(he),空(kong)氣(qi)(qi)(qi)加(jia)熱(re)(re)(re)器中電(dian)熱(re)(re)(re)元件(jian)(jian)的壁(bi)溫將(jiang)呈直線變化,如果(guo)表(biao)面負荷(he)增大,電(dian)熱(re)(re)(re)元件(jian)(jian)的壁(bi)溫將(jiang)增大,這將(jiang)降(jiang)(jiang)低空(kong)氣(qi)(qi)(qi)加(jia)熱(re)(re)(re)器中電(dian)熱(re)(re)(re)元件(jian)(jian)的使用壽命,但是如果(guo)表(biao)面負荷(he)過小,壁(bi)溫過低,空(kong)氣(qi)(qi)(qi)加(jia)熱(re)(re)(re)器換熱(re)(re)(re)器的效(xiao)率又降(jiang)(jiang)低了(le),所(suo)以空(kong)氣(qi)(qi)(qi)加(jia)熱(re)(re)(re)器中電(dian)熱(re)(re)(re)元件(jian)(jian)的表(biao)面負荷(he)的選擇(ze)比較重要。
3.空(kong)氣加(jia)(jia)熱(re)器(qi)(qi)中(zhong)(zhong)空(kong)氣終溫T2提高(gao)時,由于空(kong)氣粘(zhan)性增加(jia)(jia),氣體雷(lei)諾(nuo)數減小,使得(de)對流換熱(re)強度(du)降低,空(kong)氣加(jia)(jia)熱(re)器(qi)(qi)中(zhong)(zhong)電(dian)(dian)熱(re)元件的(de)表(biao)面溫度(du)同時上升,紅(hong)外碳硫分析儀使得(de)散熱(re)損失增加(jia)(jia),從而降低換熱(re)器(qi)(qi)的(de)效(xiao)率。當(dang)T2提高(gao)過大時,電(dian)(dian)熱(re)元件表(biao)面的(de)溫度(du)亦會大大升高(gao),致使一般電(dian)(dian)熱(re)元件無法承受,故T2的(de)增加(jia)(jia)通常受到空(kong)氣加(jia)(jia)熱(re)器(qi)(qi)中(zhong)(zhong)電(dian)(dian)熱(re)元件材(cai)料(liao)耐熱(re)性能的(de)限制。