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)(re)(re),而(er)降低了空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)內電熱(re)(re)(re)元(yuan)件表面(mian)溫(wen)度(du),不(bu)僅有(you)利于(yu)延長(chang)空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)電熱(re)(re)(re)元(yuan)件的(de)使(shi)用壽命(ming),而(er)且(qie)使(shi)得空(kong)氣(qi)電加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)散(san)熱(re)(re)(re)損(sun)失減小,因而(er)空(kong)氣(qi)換熱(re)(re)(re)器(qi)(qi)(qi)的(de)效(xiao)率提高了,但速度(du)如果過大,使(shi)得壓力損(sun)失陡(dou)增(zeng),這將不(bu)利于(yu)加(jia)(jia)熱(re)(re)(re)效(xiao)率的(de)提高。
2.若其它條件(jian)不(bu)變(bian),改變(bian)表面負(fu)荷(he),空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器中電(dian)熱(re)(re)(re)(re)元件(jian)的(de)壁(bi)(bi)溫將(jiang)呈直線(xian)變(bian)化,如果表面負(fu)荷(he)增大(da),電(dian)熱(re)(re)(re)(re)元件(jian)的(de)壁(bi)(bi)溫將(jiang)增大(da),這(zhe)將(jiang)降(jiang)低空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器中電(dian)熱(re)(re)(re)(re)元件(jian)的(de)使用壽命(ming),但是(shi)如果表面負(fu)荷(he)過(guo)小,壁(bi)(bi)溫過(guo)低,空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器換熱(re)(re)(re)(re)器的(de)效率又降(jiang)低了,所以空(kong)氣加(jia)(jia)熱(re)(re)(re)(re)器中電(dian)熱(re)(re)(re)(re)元件(jian)的(de)表面負(fu)荷(he)的(de)選擇比較重要。
3.空(kong)(kong)氣加(jia)熱(re)器中(zhong)空(kong)(kong)氣終溫T2提高(gao)(gao)時,由于空(kong)(kong)氣粘(zhan)性(xing)(xing)增(zeng)加(jia),氣體雷諾數減小,使(shi)得(de)對流(liu)換熱(re)強(qiang)度(du)降低,空(kong)(kong)氣加(jia)熱(re)器中(zhong)電(dian)熱(re)元(yuan)(yuan)件(jian)(jian)的表面溫度(du)同時上升,紅外碳硫分析儀使(shi)得(de)散熱(re)損(sun)失增(zeng)加(jia),從而降低換熱(re)器的效率(lv)。當T2提高(gao)(gao)過大時,電(dian)熱(re)元(yuan)(yuan)件(jian)(jian)表面的溫度(du)亦會大大升高(gao)(gao),致使(shi)一般電(dian)熱(re)元(yuan)(yuan)件(jian)(jian)無法(fa)承受,故T2的增(zeng)加(jia)通常(chang)受到空(kong)(kong)氣加(jia)熱(re)器中(zhong)電(dian)熱(re)元(yuan)(yuan)件(jian)(jian)材料耐熱(re)性(xing)(xing)能的限制(zhi)。