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(jiang)低了空(kong)(kong)氣加(jia)熱(re)(re)器(qi)內電熱(re)(re)元(yuan)件表面溫度,不僅有利于(yu)延長空(kong)(kong)氣加(jia)熱(re)(re)器(qi)電熱(re)(re)元(yuan)件的(de)(de)使用(yong)壽(shou)命,而(er)且使得空(kong)(kong)氣電加(jia)熱(re)(re)器(qi)散熱(re)(re)損失(shi)減小(xiao),因而(er)空(kong)(kong)氣換熱(re)(re)器(qi)的(de)(de)效率(lv)提高了,但速度如果(guo)過大,使得壓力(li)損失(shi)陡增(zeng),這(zhe)將不利于(yu)加(jia)熱(re)(re)效率(lv)的(de)(de)提高。
2.若其(qi)它條件不變,改(gai)變表面(mian)負荷,空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)(re)器(qi)(qi)中(zhong)電熱(re)(re)(re)(re)元(yuan)(yuan)(yuan)件的壁(bi)溫(wen)將呈直線變化,如果(guo)表面(mian)負荷增(zeng)大,電熱(re)(re)(re)(re)元(yuan)(yuan)(yuan)件的壁(bi)溫(wen)將增(zeng)大,這將降低空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)(re)器(qi)(qi)中(zhong)電熱(re)(re)(re)(re)元(yuan)(yuan)(yuan)件的使用壽命,但是如果(guo)表面(mian)負荷過小,壁(bi)溫(wen)過低,空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)(re)器(qi)(qi)換熱(re)(re)(re)(re)器(qi)(qi)的效率又降低了,所以空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)(re)器(qi)(qi)中(zhong)電熱(re)(re)(re)(re)元(yuan)(yuan)(yuan)件的表面(mian)負荷的選(xuan)擇比較重要。
3.空氣(qi)加(jia)(jia)(jia)熱(re)(re)器(qi)中空氣(qi)終(zhong)溫(wen)(wen)T2提(ti)高(gao)時,由于(yu)空氣(qi)粘性增(zeng)加(jia)(jia)(jia),氣(qi)體(ti)雷諾數減小(xiao),使得(de)對流換熱(re)(re)強(qiang)度(du)(du)降低(di),空氣(qi)加(jia)(jia)(jia)熱(re)(re)器(qi)中電(dian)(dian)熱(re)(re)元件的表面溫(wen)(wen)度(du)(du)同時上升(sheng)(sheng),紅外碳硫分析儀使得(de)散熱(re)(re)損失增(zeng)加(jia)(jia)(jia),從而降低(di)換熱(re)(re)器(qi)的效率。當(dang)T2提(ti)高(gao)過(guo)大時,電(dian)(dian)熱(re)(re)元件表面的溫(wen)(wen)度(du)(du)亦會大大升(sheng)(sheng)高(gao),致使一(yi)般電(dian)(dian)熱(re)(re)元件無法(fa)承受(shou),故T2的增(zeng)加(jia)(jia)(jia)通(tong)常(chang)受(shou)到空氣(qi)加(jia)(jia)(jia)熱(re)(re)器(qi)中電(dian)(dian)熱(re)(re)元件材料耐熱(re)(re)性能的限制。