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),而(er)降低了(le)空(kong)氣(qi)加(jia)熱(re)(re)器(qi)內電(dian)熱(re)(re)元件(jian)表面溫度(du),不(bu)僅有(you)利于延長空(kong)氣(qi)加(jia)熱(re)(re)器(qi)電(dian)熱(re)(re)元件(jian)的使用壽命,而(er)且(qie)使得(de)空(kong)氣(qi)電(dian)加(jia)熱(re)(re)器(qi)散(san)熱(re)(re)損失減(jian)小(xiao),因而(er)空(kong)氣(qi)換熱(re)(re)器(qi)的效率提高了(le),但速度(du)如果過大,使得(de)壓力損失陡增,這將(jiang)不(bu)利于加(jia)熱(re)(re)效率的提高。
2.若其(qi)它條(tiao)件不(bu)變(bian),改變(bian)表(biao)面負荷(he),空(kong)氣(qi)(qi)(qi)加(jia)熱(re)器(qi)中電(dian)熱(re)元(yuan)件的壁(bi)(bi)溫將(jiang)呈(cheng)直線變(bian)化,如果表(biao)面負荷(he)增大,電(dian)熱(re)元(yuan)件的壁(bi)(bi)溫將(jiang)增大,這將(jiang)降低空(kong)氣(qi)(qi)(qi)加(jia)熱(re)器(qi)中電(dian)熱(re)元(yuan)件的使(shi)用壽(shou)命(ming),但(dan)是如果表(biao)面負荷(he)過小,壁(bi)(bi)溫過低,空(kong)氣(qi)(qi)(qi)加(jia)熱(re)器(qi)換熱(re)器(qi)的效率(lv)又降低了(le),所以空(kong)氣(qi)(qi)(qi)加(jia)熱(re)器(qi)中電(dian)熱(re)元(yuan)件的表(biao)面負荷(he)的選(xuan)擇比較重要。
3.空氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)空氣(qi)終溫T2提高(gao)時,由于空氣(qi)粘性(xing)增加(jia)(jia),氣(qi)體雷(lei)諾數減小(xiao),使(shi)(shi)得對(dui)流(liu)換熱(re)(re)(re)強度(du)降低,空氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)元(yuan)件(jian)的表(biao)面溫度(du)同時上升,紅外碳硫分析儀使(shi)(shi)得散熱(re)(re)(re)損失增加(jia)(jia),從而降低換熱(re)(re)(re)器(qi)的效率。當T2提高(gao)過大時,電熱(re)(re)(re)元(yuan)件(jian)表(biao)面的溫度(du)亦(yi)會大大升高(gao),致使(shi)(shi)一般電熱(re)(re)(re)元(yuan)件(jian)無法承受,故T2的增加(jia)(jia)通常(chang)受到空氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電熱(re)(re)(re)元(yuan)件(jian)材料耐熱(re)(re)(re)性(xing)能的限(xian)制。