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)熱(re),而降低了(le)空氣加熱(re)器(qi)(qi)內電(dian)熱(re)元(yuan)件表面溫(wen)度(du),不僅有利于延長(chang)空氣加熱(re)器(qi)(qi)電(dian)熱(re)元(yuan)件的使用壽命,而且使得空氣電(dian)加熱(re)器(qi)(qi)散熱(re)損失減小,因而空氣換(huan)熱(re)器(qi)(qi)的效(xiao)率(lv)提(ti)高了(le),但速度(du)如果(guo)過大,使得壓力損失陡(dou)增,這(zhe)將(jiang)不利于加熱(re)效(xiao)率(lv)的提(ti)高。
2.若(ruo)其它條件(jian)(jian)不變(bian)(bian),改變(bian)(bian)表(biao)面(mian)(mian)負(fu)荷(he)(he)(he),空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器中(zhong)(zhong)電熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)壁溫(wen)將(jiang)呈直線變(bian)(bian)化,如果(guo)(guo)表(biao)面(mian)(mian)負(fu)荷(he)(he)(he)增大,電熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)壁溫(wen)將(jiang)增大,這將(jiang)降低(di)空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器中(zhong)(zhong)電熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)使(shi)用壽命,但是如果(guo)(guo)表(biao)面(mian)(mian)負(fu)荷(he)(he)(he)過小,壁溫(wen)過低(di),空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器換熱(re)(re)(re)器的(de)效率又(you)降低(di)了,所(suo)以空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器中(zhong)(zhong)電熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)表(biao)面(mian)(mian)負(fu)荷(he)(he)(he)的(de)選擇(ze)比較重要。
3.空(kong)(kong)(kong)氣加熱(re)器中(zhong)空(kong)(kong)(kong)氣終(zhong)溫T2提高時,由于空(kong)(kong)(kong)氣粘性增加,氣體雷諾數減小,使得對流換(huan)熱(re)強度(du)降低,空(kong)(kong)(kong)氣加熱(re)器中(zhong)電熱(re)元件(jian)的(de)(de)表(biao)面溫度(du)同(tong)時上(shang)升,紅外碳(tan)硫分析儀(yi)使得散熱(re)損失增加,從而降低換(huan)熱(re)器的(de)(de)效率。當T2提高過(guo)大(da)時,電熱(re)元件(jian)表(biao)面的(de)(de)溫度(du)亦會大(da)大(da)升高,致使一般電熱(re)元件(jian)無法承受,故T2的(de)(de)增加通常受到空(kong)(kong)(kong)氣加熱(re)器中(zhong)電熱(re)元件(jian)材料耐(nai)熱(re)性能的(de)(de)限(xian)制。