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(re),而降低了(le)空氣加熱(re)器(qi)(qi)內電(dian)熱(re)元(yuan)件(jian)表(biao)面溫度,不僅有利于延長(chang)空氣加熱(re)器(qi)(qi)電(dian)熱(re)元(yuan)件(jian)的使(shi)用壽命,而且使(shi)得(de)空氣電(dian)加熱(re)器(qi)(qi)散熱(re)損(sun)失(shi)減小,因而空氣換熱(re)器(qi)(qi)的效(xiao)率提高了(le),但(dan)速度如果過大,使(shi)得(de)壓(ya)力損(sun)失(shi)陡增,這將(jiang)不利于加熱(re)效(xiao)率的提高。
2.若其它條(tiao)件(jian)不變(bian),改變(bian)表(biao)面(mian)負荷,空(kong)(kong)氣加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元件(jian)的(de)壁(bi)(bi)溫(wen)將呈直線變(bian)化,如果表(biao)面(mian)負荷增大,電(dian)熱(re)(re)(re)元件(jian)的(de)壁(bi)(bi)溫(wen)將增大,這(zhe)將降低(di)空(kong)(kong)氣加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元件(jian)的(de)使用壽命,但是如果表(biao)面(mian)負荷過小,壁(bi)(bi)溫(wen)過低(di),空(kong)(kong)氣加(jia)(jia)熱(re)(re)(re)器(qi)換熱(re)(re)(re)器(qi)的(de)效率又降低(di)了,所以空(kong)(kong)氣加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元件(jian)的(de)表(biao)面(mian)負荷的(de)選擇比較重要。
3.空(kong)(kong)氣(qi)(qi)加(jia)熱(re)(re)器(qi)(qi)中空(kong)(kong)氣(qi)(qi)終溫(wen)T2提高時,由于空(kong)(kong)氣(qi)(qi)粘(zhan)性增加(jia),氣(qi)(qi)體(ti)雷諾數減(jian)小,使(shi)(shi)得(de)(de)對流換(huan)熱(re)(re)強度(du)(du)降低(di),空(kong)(kong)氣(qi)(qi)加(jia)熱(re)(re)器(qi)(qi)中電(dian)熱(re)(re)元件的(de)(de)(de)表面(mian)溫(wen)度(du)(du)同時上(shang)升,紅外碳硫分析儀使(shi)(shi)得(de)(de)散熱(re)(re)損(sun)失增加(jia),從(cong)而降低(di)換(huan)熱(re)(re)器(qi)(qi)的(de)(de)(de)效(xiao)率(lv)。當T2提高過大時,電(dian)熱(re)(re)元件表面(mian)的(de)(de)(de)溫(wen)度(du)(du)亦會大大升高,致使(shi)(shi)一(yi)般電(dian)熱(re)(re)元件無法承受,故T2的(de)(de)(de)增加(jia)通常(chang)受到空(kong)(kong)氣(qi)(qi)加(jia)熱(re)(re)器(qi)(qi)中電(dian)熱(re)(re)元件材料耐熱(re)(re)性能的(de)(de)(de)限制。