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(er)(er)(er)降低了(le)空(kong)氣(qi)加(jia)(jia)熱(re)器內(nei)電(dian)(dian)熱(re)元件表面(mian)溫(wen)度,不(bu)僅(jin)有(you)利(li)于(yu)延長空(kong)氣(qi)加(jia)(jia)熱(re)器電(dian)(dian)熱(re)元件的使用(yong)壽(shou)命,而(er)(er)(er)且使得空(kong)氣(qi)電(dian)(dian)加(jia)(jia)熱(re)器散(san)熱(re)損失減小,因而(er)(er)(er)空(kong)氣(qi)換熱(re)器的效率提(ti)(ti)高了(le),但(dan)速度如果過大(da),使得壓力損失陡增,這將不(bu)利(li)于(yu)加(jia)(jia)熱(re)效率的提(ti)(ti)高。
2.若其它條件不變(bian),改變(bian)表面(mian)(mian)負(fu)荷(he),空氣加熱(re)器中電(dian)熱(re)元(yuan)(yuan)件的(de)壁(bi)溫將(jiang)呈直(zhi)線變(bian)化(hua),如(ru)果表面(mian)(mian)負(fu)荷(he)增(zeng)(zeng)大(da),電(dian)熱(re)元(yuan)(yuan)件的(de)壁(bi)溫將(jiang)增(zeng)(zeng)大(da),這(zhe)將(jiang)降低空氣加熱(re)器中電(dian)熱(re)元(yuan)(yuan)件的(de)使用(yong)壽(shou)命,但是如(ru)果表面(mian)(mian)負(fu)荷(he)過小(xiao),壁(bi)溫過低,空氣加熱(re)器換熱(re)器的(de)效率又降低了(le),所以空氣加熱(re)器中電(dian)熱(re)元(yuan)(yuan)件的(de)表面(mian)(mian)負(fu)荷(he)的(de)選(xuan)擇比較(jiao)重(zhong)要。
3.空(kong)氣加熱(re)(re)(re)器中(zhong)(zhong)空(kong)氣終(zhong)溫T2提高(gao)時(shi),由于(yu)空(kong)氣粘性增(zeng)(zeng)加,氣體雷諾數減小(xiao),使得對流換(huan)熱(re)(re)(re)強度(du)(du)(du)降(jiang)低(di),空(kong)氣加熱(re)(re)(re)器中(zhong)(zhong)電(dian)熱(re)(re)(re)元(yuan)件(jian)的(de)表面(mian)溫度(du)(du)(du)同(tong)時(shi)上升,紅外碳硫(liu)分(fen)析儀使得散熱(re)(re)(re)損失(shi)增(zeng)(zeng)加,從(cong)而降(jiang)低(di)換(huan)熱(re)(re)(re)器的(de)效率(lv)。當(dang)T2提高(gao)過大(da)(da)時(shi),電(dian)熱(re)(re)(re)元(yuan)件(jian)表面(mian)的(de)溫度(du)(du)(du)亦(yi)會大(da)(da)大(da)(da)升高(gao),致使一(yi)般電(dian)熱(re)(re)(re)元(yuan)件(jian)無法承(cheng)受,故T2的(de)增(zeng)(zeng)加通常(chang)受到(dao)空(kong)氣加熱(re)(re)(re)器中(zhong)(zhong)電(dian)熱(re)(re)(re)元(yuan)件(jian)材料耐(nai)熱(re)(re)(re)性能的(de)限制。