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),而降低了空氣加(jia)(jia)熱(re)器(qi)內電(dian)熱(re)元件表(biao)面溫度,不僅有利于延長空氣加(jia)(jia)熱(re)器(qi)電(dian)熱(re)元件的(de)使(shi)用壽命,而且(qie)使(shi)得空氣電(dian)加(jia)(jia)熱(re)器(qi)散熱(re)損失減小,因而空氣換熱(re)器(qi)的(de)效(xiao)率(lv)提(ti)高了,但速度如(ru)果過大,使(shi)得壓力損失陡(dou)增,這將不利于加(jia)(jia)熱(re)效(xiao)率(lv)的(de)提(ti)高。
2.若其它(ta)條(tiao)件(jian)(jian)(jian)不(bu)變,改變表面(mian)負荷(he),空氣(qi)(qi)(qi)加熱(re)(re)(re)器(qi)中電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的壁溫將呈直線變化,如果表面(mian)負荷(he)增(zeng)大,電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的壁溫將增(zeng)大,這將降低(di)空氣(qi)(qi)(qi)加熱(re)(re)(re)器(qi)中電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的使用壽命,但是如果表面(mian)負荷(he)過小,壁溫過低(di),空氣(qi)(qi)(qi)加熱(re)(re)(re)器(qi)換熱(re)(re)(re)器(qi)的效(xiao)率又(you)降低(di)了,所以空氣(qi)(qi)(qi)加熱(re)(re)(re)器(qi)中電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的表面(mian)負荷(he)的選擇(ze)比較(jiao)重要。
3.空氣加(jia)熱(re)(re)(re)(re)(re)(re)器(qi)中(zhong)空氣終溫T2提高時,由于空氣粘性增(zeng)加(jia),氣體雷諾(nuo)數減小,使(shi)得(de)對(dui)流換熱(re)(re)(re)(re)(re)(re)強度降低(di),空氣加(jia)熱(re)(re)(re)(re)(re)(re)器(qi)中(zhong)電(dian)(dian)熱(re)(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)的(de)(de)表面溫度同時上(shang)升,紅(hong)外碳硫分析儀(yi)使(shi)得(de)散熱(re)(re)(re)(re)(re)(re)損失(shi)增(zeng)加(jia),從而降低(di)換熱(re)(re)(re)(re)(re)(re)器(qi)的(de)(de)效(xiao)率。當(dang)T2提高過大時,電(dian)(dian)熱(re)(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)表面的(de)(de)溫度亦(yi)會大大升高,致使(shi)一般電(dian)(dian)熱(re)(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)無法承受,故T2的(de)(de)增(zeng)加(jia)通常受到空氣加(jia)熱(re)(re)(re)(re)(re)(re)器(qi)中(zhong)電(dian)(dian)熱(re)(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)材(cai)料耐熱(re)(re)(re)(re)(re)(re)性能的(de)(de)限制。