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(liu)換熱(re)(re)(re),而降低了(le)空(kong)氣加熱(re)(re)(re)器內電(dian)(dian)熱(re)(re)(re)元(yuan)件表面溫度,不(bu)僅有利于延長空(kong)氣加熱(re)(re)(re)器電(dian)(dian)熱(re)(re)(re)元(yuan)件的(de)(de)使(shi)用壽命(ming),而且使(shi)得空(kong)氣電(dian)(dian)加熱(re)(re)(re)器散熱(re)(re)(re)損(sun)失(shi)減小,因而空(kong)氣換熱(re)(re)(re)器的(de)(de)效(xiao)率提高(gao)了(le),但速度如果過(guo)大,使(shi)得壓力損(sun)失(shi)陡增,這將(jiang)不(bu)利于加熱(re)(re)(re)效(xiao)率的(de)(de)提高(gao)。
2.若其它條(tiao)件(jian)不(bu)變(bian)(bian),改變(bian)(bian)表(biao)(biao)面負荷,空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)(zhong)電熱(re)(re)(re)元件(jian)的(de)壁(bi)溫(wen)將呈直線變(bian)(bian)化,如(ru)(ru)果表(biao)(biao)面負荷增(zeng)大(da),電熱(re)(re)(re)元件(jian)的(de)壁(bi)溫(wen)將增(zeng)大(da),這將降低空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)(zhong)電熱(re)(re)(re)元件(jian)的(de)使用壽(shou)命,但是如(ru)(ru)果表(biao)(biao)面負荷過小(xiao),壁(bi)溫(wen)過低,空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器(qi)換熱(re)(re)(re)器(qi)的(de)效率又降低了,所以空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)(zhong)電熱(re)(re)(re)元件(jian)的(de)表(biao)(biao)面負荷的(de)選擇比(bi)較重要。
3.空氣(qi)加(jia)熱(re)(re)(re)器中空氣(qi)終溫T2提(ti)(ti)高(gao)時(shi),由于空氣(qi)粘性增加(jia),氣(qi)體雷(lei)諾數減小,使(shi)得對流(liu)換(huan)熱(re)(re)(re)強度降(jiang)低,空氣(qi)加(jia)熱(re)(re)(re)器中電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)表面(mian)(mian)溫度同時(shi)上升,紅外碳硫分(fen)析儀使(shi)得散(san)熱(re)(re)(re)損失增加(jia),從而(er)降(jiang)低換(huan)熱(re)(re)(re)器的(de)效率。當T2提(ti)(ti)高(gao)過大時(shi),電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)表面(mian)(mian)的(de)溫度亦會(hui)大大升高(gao),致使(shi)一般(ban)電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)無法承(cheng)受,故T2的(de)增加(jia)通常受到(dao)空氣(qi)加(jia)熱(re)(re)(re)器中電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)材料耐熱(re)(re)(re)性能(neng)的(de)限制。