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(liu)換(huan)(huan)熱(re)(re)(re)，而降低(di)了空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)內電熱(re)(re)(re)元(yuan)件(jian)(jian)表面溫(wen)度，不僅(jin)有利于(yu)延(yan)長空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)電熱(re)(re)(re)元(yuan)件(jian)(jian)的使(shi)用(yong)壽命，而且使(shi)得空(kong)氣(qi)電加(jia)熱(re)(re)(re)器(qi)散熱(re)(re)(re)損失減小，因而空(kong)氣(qi)換(huan)(huan)熱(re)(re)(re)器(qi)的效(xiao)率(lv)(lv)提(ti)高了，但速度如果過大，使(shi)得壓力(li)損失陡增，這將不利于(yu)加(jia)熱(re)(re)(re)效(xiao)率(lv)(lv)的提(ti)高。

     2.若其它條件(jian)(jian)不變，改變表面(mian)負荷(he)，空(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)電(dian)(dian)熱(re)(re)元(yuan)件(jian)(jian)的(de)(de)壁溫(wen)將呈直線變化，如(ru)果表面(mian)負荷(he)增大(da)(da)，電(dian)(dian)熱(re)(re)元(yuan)件(jian)(jian)的(de)(de)壁溫(wen)將增大(da)(da)，這(zhe)將降低(di)空(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)電(dian)(dian)熱(re)(re)元(yuan)件(jian)(jian)的(de)(de)使用壽命，但是如(ru)果表面(mian)負荷(he)過(guo)小，壁溫(wen)過(guo)低(di)，空(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)換熱(re)(re)器(qi)(qi)的(de)(de)效(xiao)率(lv)又(you)降低(di)了，所以空(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)電(dian)(dian)熱(re)(re)元(yuan)件(jian)(jian)的(de)(de)表面(mian)負荷(he)的(de)(de)選擇比較重要。

     3.空氣(qi)(qi)加(jia)(jia)熱(re)(re)器中(zhong)空氣(qi)(qi)終溫T2提高時(shi)(shi)，由于空氣(qi)(qi)粘性增加(jia)(jia)，氣(qi)(qi)體雷諾數(shu)減小，使(shi)(shi)得對流換(huan)熱(re)(re)強(qiang)度(du)降低，空氣(qi)(qi)加(jia)(jia)熱(re)(re)器中(zhong)電(dian)熱(re)(re)元件的(de)表面(mian)溫度(du)同時(shi)(shi)上升，紅外碳硫分(fen)析儀使(shi)(shi)得散熱(re)(re)損失增加(jia)(jia)，從而(er)降低換(huan)熱(re)(re)器的(de)效率。當T2提高過大時(shi)(shi)，電(dian)熱(re)(re)元件表面(mian)的(de)溫度(du)亦會大大升高，致使(shi)(shi)一(yi)般電(dian)熱(re)(re)元件無法承受(shou)(shou)，故T2的(de)增加(jia)(jia)通常受(shou)(shou)到空氣(qi)(qi)加(jia)(jia)熱(re)(re)器中(zhong)電(dian)熱(re)(re)元件材(cai)料耐熱(re)(re)性能(neng)的(de)限制。