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)降低了空(kong)氣加熱(re)(re)器(qi)內電(dian)熱(re)(re)元(yuan)件表面溫(wen)度,不僅有利(li)于延(yan)長(chang)空(kong)氣加熱(re)(re)器(qi)電(dian)熱(re)(re)元(yuan)件的(de)使用壽命,而(er)且使得空(kong)氣電(dian)加熱(re)(re)器(qi)散熱(re)(re)損(sun)失(shi)(shi)減小,因而(er)空(kong)氣換熱(re)(re)器(qi)的(de)效(xiao)率(lv)提高了,但(dan)速度如果(guo)過大,使得壓(ya)力損(sun)失(shi)(shi)陡(dou)增,這將不利(li)于加熱(re)(re)效(xiao)率(lv)的(de)提高。
2.若其(qi)它條件(jian)不變,改變表(biao)面(mian)(mian)負荷,空(kong)(kong)(kong)氣(qi)加(jia)(jia)(jia)熱(re)(re)器中電(dian)熱(re)(re)元件(jian)的壁(bi)溫將呈直(zhi)線變化,如果(guo)表(biao)面(mian)(mian)負荷增(zeng)大(da),電(dian)熱(re)(re)元件(jian)的壁(bi)溫將增(zeng)大(da),這將降(jiang)(jiang)低(di)(di)空(kong)(kong)(kong)氣(qi)加(jia)(jia)(jia)熱(re)(re)器中電(dian)熱(re)(re)元件(jian)的使用壽(shou)命,但是如果(guo)表(biao)面(mian)(mian)負荷過小,壁(bi)溫過低(di)(di),空(kong)(kong)(kong)氣(qi)加(jia)(jia)(jia)熱(re)(re)器換熱(re)(re)器的效率又降(jiang)(jiang)低(di)(di)了,所(suo)以空(kong)(kong)(kong)氣(qi)加(jia)(jia)(jia)熱(re)(re)器中電(dian)熱(re)(re)元件(jian)的表(biao)面(mian)(mian)負荷的選擇比較重要。
3.空氣(qi)加熱(re)(re)(re)(re)(re)器(qi)中空氣(qi)終(zhong)溫T2提(ti)高(gao)時,由于空氣(qi)粘性增加,氣(qi)體(ti)雷諾數減(jian)小,使得對流(liu)換熱(re)(re)(re)(re)(re)強(qiang)度(du)(du)(du)降(jiang)低,空氣(qi)加熱(re)(re)(re)(re)(re)器(qi)中電熱(re)(re)(re)(re)(re)元(yuan)件的表面(mian)溫度(du)(du)(du)同時上升(sheng),紅外碳硫分析儀使得散熱(re)(re)(re)(re)(re)損(sun)失增加,從(cong)而(er)降(jiang)低換熱(re)(re)(re)(re)(re)器(qi)的效(xiao)率(lv)。當T2提(ti)高(gao)過大時,電熱(re)(re)(re)(re)(re)元(yuan)件表面(mian)的溫度(du)(du)(du)亦(yi)會大大升(sheng)高(gao),致使一般(ban)電熱(re)(re)(re)(re)(re)元(yuan)件無法承(cheng)受(shou),故(gu)T2的增加通常受(shou)到空氣(qi)加熱(re)(re)(re)(re)(re)器(qi)中電熱(re)(re)(re)(re)(re)元(yuan)件材料耐(nai)熱(re)(re)(re)(re)(re)性能的限制(zhi)。