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)換熱(re),而降低了空氣(qi)加熱(re)器(qi)內電(dian)熱(re)元(yuan)件表(biao)面(mian)溫(wen)度,不僅(jin)有利于(yu)延長(chang)空氣(qi)加熱(re)器(qi)電(dian)熱(re)元(yuan)件的(de)使用(yong)壽命,而且使得空氣(qi)電(dian)加熱(re)器(qi)散熱(re)損(sun)失減小,因而空氣(qi)換熱(re)器(qi)的(de)效(xiao)率提高了,但(dan)速(su)度如果過大,使得壓力損(sun)失陡增,這將不利于(yu)加熱(re)效(xiao)率的(de)提高。
2.若其(qi)它(ta)條件(jian)不變(bian),改變(bian)表(biao)(biao)面負(fu)(fu)荷(he)(he)(he),空(kong)(kong)氣加(jia)熱(re)器(qi)(qi)中電(dian)熱(re)元件(jian)的(de)壁溫(wen)將(jiang)呈直線變(bian)化(hua),如果表(biao)(biao)面負(fu)(fu)荷(he)(he)(he)增(zeng)大,電(dian)熱(re)元件(jian)的(de)壁溫(wen)將(jiang)增(zeng)大,這將(jiang)降低空(kong)(kong)氣加(jia)熱(re)器(qi)(qi)中電(dian)熱(re)元件(jian)的(de)使用(yong)壽命,但是如果表(biao)(biao)面負(fu)(fu)荷(he)(he)(he)過(guo)小(xiao),壁溫(wen)過(guo)低,空(kong)(kong)氣加(jia)熱(re)器(qi)(qi)換熱(re)器(qi)(qi)的(de)效率又降低了,所以空(kong)(kong)氣加(jia)熱(re)器(qi)(qi)中電(dian)熱(re)元件(jian)的(de)表(biao)(biao)面負(fu)(fu)荷(he)(he)(he)的(de)選擇比較重要。
3.空氣(qi)(qi)(qi)(qi)加熱(re)(re)器中(zhong)(zhong)空氣(qi)(qi)(qi)(qi)終溫T2提高(gao)時(shi),由(you)于空氣(qi)(qi)(qi)(qi)粘性增加,氣(qi)(qi)(qi)(qi)體雷諾數減小(xiao),使(shi)得對流換熱(re)(re)強(qiang)度降低,空氣(qi)(qi)(qi)(qi)加熱(re)(re)器中(zhong)(zhong)電(dian)(dian)熱(re)(re)元(yuan)件(jian)的表面(mian)溫度同時(shi)上升(sheng),紅(hong)外碳硫分析儀使(shi)得散熱(re)(re)損(sun)失增加,從而(er)降低換熱(re)(re)器的效率(lv)。當T2提高(gao)過大時(shi),電(dian)(dian)熱(re)(re)元(yuan)件(jian)表面(mian)的溫度亦會大大升(sheng)高(gao),致使(shi)一般電(dian)(dian)熱(re)(re)元(yuan)件(jian)無法承受,故T2的增加通常(chang)受到空氣(qi)(qi)(qi)(qi)加熱(re)(re)器中(zhong)(zhong)電(dian)(dian)熱(re)(re)元(yuan)件(jian)材料耐熱(re)(re)性能的限制。