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),而(er)降低了空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)內電(dian)熱(re)(re)(re)元件(jian)表面(mian)溫(wen)度,不(bu)僅有利(li)于(yu)延長空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)電(dian)熱(re)(re)(re)元件(jian)的使用(yong)壽(shou)命,而(er)且使得空(kong)(kong)氣(qi)電(dian)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)散熱(re)(re)(re)損(sun)失減小,因而(er)空(kong)(kong)氣(qi)換熱(re)(re)(re)器(qi)(qi)(qi)的效率(lv)提高了,但速度如果過大(da),使得壓力(li)損(sun)失陡增(zeng),這(zhe)將不(bu)利(li)于(yu)加(jia)(jia)熱(re)(re)(re)效率(lv)的提高。
2.若其(qi)它條件(jian)(jian)不(bu)變,改變表面負(fu)荷,空(kong)氣(qi)加(jia)熱(re)器中電熱(re)元(yuan)(yuan)(yuan)件(jian)(jian)的壁(bi)(bi)溫(wen)將(jiang)呈直線變化(hua),如(ru)果表面負(fu)荷增大,電熱(re)元(yuan)(yuan)(yuan)件(jian)(jian)的壁(bi)(bi)溫(wen)將(jiang)增大,這(zhe)將(jiang)降低空(kong)氣(qi)加(jia)熱(re)器中電熱(re)元(yuan)(yuan)(yuan)件(jian)(jian)的使用壽(shou)命,但是(shi)如(ru)果表面負(fu)荷過小,壁(bi)(bi)溫(wen)過低,空(kong)氣(qi)加(jia)熱(re)器換熱(re)器的效率又(you)降低了,所以空(kong)氣(qi)加(jia)熱(re)器中電熱(re)元(yuan)(yuan)(yuan)件(jian)(jian)的表面負(fu)荷的選擇比較重(zhong)要(yao)。
3.空氣加(jia)熱(re)器中(zhong)空氣終溫T2提高(gao)時,由于空氣粘性(xing)增(zeng)加(jia),氣體雷諾數減小,使(shi)得對流換(huan)熱(re)強(qiang)度降低(di),空氣加(jia)熱(re)器中(zhong)電(dian)熱(re)元件(jian)(jian)的(de)表(biao)面溫度同時上升,紅外碳硫分析(xi)儀使(shi)得散熱(re)損失(shi)增(zeng)加(jia),從而降低(di)換(huan)熱(re)器的(de)效率。當T2提高(gao)過(guo)大(da)(da)時,電(dian)熱(re)元件(jian)(jian)表(biao)面的(de)溫度亦會大(da)(da)大(da)(da)升高(gao),致使(shi)一般電(dian)熱(re)元件(jian)(jian)無法承受,故T2的(de)增(zeng)加(jia)通常受到空氣加(jia)熱(re)器中(zhong)電(dian)熱(re)元件(jian)(jian)材料耐熱(re)性(xing)能(neng)的(de)限制。