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),而降低了空(kong)氣(qi)加熱(re)器(qi)(qi)內電熱(re)元(yuan)件表面(mian)溫(wen)度,不僅有利于(yu)延長空(kong)氣(qi)加熱(re)器(qi)(qi)電熱(re)元(yuan)件的使用(yong)壽命,而且使得(de)空(kong)氣(qi)電加熱(re)器(qi)(qi)散熱(re)損(sun)失減(jian)小,因而空(kong)氣(qi)換熱(re)器(qi)(qi)的效(xiao)(xiao)率(lv)提(ti)高了,但速(su)度如果過大,使得(de)壓(ya)力(li)損(sun)失陡增(zeng),這將不利于(yu)加熱(re)效(xiao)(xiao)率(lv)的提(ti)高。
2.若其它條件(jian)不變,改變表面(mian)(mian)負(fu)荷(he)(he),空(kong)氣加(jia)(jia)熱器(qi)中電熱元(yuan)件(jian)的壁(bi)溫(wen)將(jiang)呈直(zhi)線變化,如(ru)(ru)果(guo)表面(mian)(mian)負(fu)荷(he)(he)增大,電熱元(yuan)件(jian)的壁(bi)溫(wen)將(jiang)增大,這將(jiang)降低空(kong)氣加(jia)(jia)熱器(qi)中電熱元(yuan)件(jian)的使用壽命,但是如(ru)(ru)果(guo)表面(mian)(mian)負(fu)荷(he)(he)過小,壁(bi)溫(wen)過低,空(kong)氣加(jia)(jia)熱器(qi)換熱器(qi)的效率又降低了,所(suo)以空(kong)氣加(jia)(jia)熱器(qi)中電熱元(yuan)件(jian)的表面(mian)(mian)負(fu)荷(he)(he)的選擇比較重要。
3.空氣(qi)加(jia)(jia)(jia)熱(re)(re)器(qi)中空氣(qi)終溫(wen)T2提(ti)高時,由于空氣(qi)粘性(xing)(xing)增(zeng)加(jia)(jia)(jia),氣(qi)體雷諾數減小,使得對流換熱(re)(re)強度(du)降(jiang)低,空氣(qi)加(jia)(jia)(jia)熱(re)(re)器(qi)中電(dian)熱(re)(re)元(yuan)(yuan)(yuan)件的表(biao)面溫(wen)度(du)同(tong)時上升,紅外碳硫(liu)分析儀使得散熱(re)(re)損失增(zeng)加(jia)(jia)(jia),從而降(jiang)低換熱(re)(re)器(qi)的效率(lv)。當T2提(ti)高過大時,電(dian)熱(re)(re)元(yuan)(yuan)(yuan)件表(biao)面的溫(wen)度(du)亦會(hui)大大升高,致使一般電(dian)熱(re)(re)元(yuan)(yuan)(yuan)件無法承受(shou),故T2的增(zeng)加(jia)(jia)(jia)通常受(shou)到(dao)空氣(qi)加(jia)(jia)(jia)熱(re)(re)器(qi)中電(dian)熱(re)(re)元(yuan)(yuan)(yuan)件材(cai)料耐熱(re)(re)性(xing)(xing)能的限制。