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)(re),而降低了空(kong)氣(qi)加(jia)熱(re)(re)器內電(dian)熱(re)(re)元(yuan)件(jian)表面溫度(du),不僅有利于(yu)延長空(kong)氣(qi)加(jia)熱(re)(re)器電(dian)熱(re)(re)元(yuan)件(jian)的使(shi)用壽命,而且使(shi)得(de)(de)空(kong)氣(qi)電(dian)加(jia)熱(re)(re)器散熱(re)(re)損(sun)失(shi)減(jian)小,因(yin)而空(kong)氣(qi)換(huan)熱(re)(re)器的效率提(ti)高了,但(dan)速度(du)如果過大,使(shi)得(de)(de)壓力損(sun)失(shi)陡增(zeng),這將不利于(yu)加(jia)熱(re)(re)效率的提(ti)高。
2.若(ruo)其它條件不變(bian),改變(bian)表(biao)(biao)(biao)(biao)面負荷(he),空(kong)氣(qi)加(jia)熱(re)(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)(re)元件的壁(bi)(bi)(bi)溫將呈直線變(bian)化,如果表(biao)(biao)(biao)(biao)面負荷(he)增大,電熱(re)(re)(re)(re)元件的壁(bi)(bi)(bi)溫將增大,這(zhe)將降(jiang)低空(kong)氣(qi)加(jia)熱(re)(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)(re)元件的使用(yong)壽命,但是如果表(biao)(biao)(biao)(biao)面負荷(he)過(guo)小,壁(bi)(bi)(bi)溫過(guo)低,空(kong)氣(qi)加(jia)熱(re)(re)(re)(re)器(qi)換熱(re)(re)(re)(re)器(qi)的效率又降(jiang)低了,所(suo)以(yi)空(kong)氣(qi)加(jia)熱(re)(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)(re)元件的表(biao)(biao)(biao)(biao)面負荷(he)的選(xuan)擇比較重要。
3.空(kong)氣(qi)(qi)加(jia)熱(re)器(qi)(qi)中(zhong)空(kong)氣(qi)(qi)終溫T2提高(gao)時(shi),由于空(kong)氣(qi)(qi)粘性增加(jia),氣(qi)(qi)體雷諾數減小,使(shi)得對(dui)流換熱(re)強度降(jiang)低,空(kong)氣(qi)(qi)加(jia)熱(re)器(qi)(qi)中(zhong)電熱(re)元(yuan)(yuan)件(jian)的表面(mian)溫度同時(shi)上(shang)升(sheng),紅外碳硫分(fen)析儀使(shi)得散熱(re)損失增加(jia),從而降(jiang)低換熱(re)器(qi)(qi)的效率(lv)。當T2提高(gao)過大時(shi),電熱(re)元(yuan)(yuan)件(jian)表面(mian)的溫度亦會大大升(sheng)高(gao),致使(shi)一般電熱(re)元(yuan)(yuan)件(jian)無法承受,故(gu)T2的增加(jia)通常受到空(kong)氣(qi)(qi)加(jia)熱(re)器(qi)(qi)中(zhong)電熱(re)元(yuan)(yuan)件(jian)材(cai)料耐熱(re)性能的限制。