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(dui)流換熱，而降(jiang)低了空(kong)(kong)氣(qi)(qi)加(jia)熱器內電(dian)(dian)熱元件(jian)表(biao)面溫(wen)度，不僅(jin)有利于(yu)延長空(kong)(kong)氣(qi)(qi)加(jia)熱器電(dian)(dian)熱元件(jian)的使用壽命，而且使得空(kong)(kong)氣(qi)(qi)電(dian)(dian)加(jia)熱器散熱損(sun)失減小(xiao)，因而空(kong)(kong)氣(qi)(qi)換熱器的效率(lv)提(ti)高(gao)了，但速度如果過大，使得壓(ya)力(li)損(sun)失陡(dou)增，這將不利于(yu)加(jia)熱效率(lv)的提(ti)高(gao)。

     2.若(ruo)其它條件不變，改變表(biao)面(mian)(mian)負荷(he)，空(kong)氣加熱(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)元(yuan)件的壁溫(wen)將呈直線變化，如果表(biao)面(mian)(mian)負荷(he)增大，電熱(re)(re)(re)元(yuan)件的壁溫(wen)將增大，這將降低空(kong)氣加熱(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)元(yuan)件的使用壽命(ming)，但是(shi)如果表(biao)面(mian)(mian)負荷(he)過小(xiao)，壁溫(wen)過低，空(kong)氣加熱(re)(re)(re)器(qi)換熱(re)(re)(re)器(qi)的效率(lv)又降低了，所(suo)以空(kong)氣加熱(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)元(yuan)件的表(biao)面(mian)(mian)負荷(he)的選擇(ze)比(bi)較重要。

     3.空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器(qi)中(zhong)空(kong)(kong)氣(qi)終溫T2提高時，由于空(kong)(kong)氣(qi)粘性增加(jia)(jia)，氣(qi)體(ti)雷(lei)諾數減小，使(shi)得(de)(de)對流(liu)換(huan)熱(re)強(qiang)度(du)降低，空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器(qi)中(zhong)電(dian)(dian)熱(re)元(yuan)件(jian)的表(biao)面溫度(du)同(tong)時上升，紅外(wai)碳硫分析儀(yi)使(shi)得(de)(de)散(san)熱(re)損失增加(jia)(jia)，從而降低換(huan)熱(re)器(qi)的效(xiao)率。當(dang)T2提高過大時，電(dian)(dian)熱(re)元(yuan)件(jian)表(biao)面的溫度(du)亦會大大升高，致使(shi)一般電(dian)(dian)熱(re)元(yuan)件(jian)無法承(cheng)受(shou)，故T2的增加(jia)(jia)通常受(shou)到(dao)空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器(qi)中(zhong)電(dian)(dian)熱(re)元(yuan)件(jian)材料耐熱(re)性能的限制。