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)降低(di)了空(kong)氣加熱(re)器(qi)內電(dian)熱(re)元件(jian)表面溫度,不僅(jin)有(you)利(li)于延長空(kong)氣加熱(re)器(qi)電(dian)熱(re)元件(jian)的(de)使(shi)用壽命,而(er)且使(shi)得(de)(de)空(kong)氣電(dian)加熱(re)器(qi)散熱(re)損失(shi)(shi)減(jian)小(xiao),因(yin)而(er)空(kong)氣換熱(re)器(qi)的(de)效率提高了,但(dan)速度如果(guo)過大,使(shi)得(de)(de)壓力(li)損失(shi)(shi)陡增,這將不利(li)于加熱(re)效率的(de)提高。
2.若其它條件(jian)(jian)(jian)不變,改變表面(mian)負(fu)(fu)荷(he)(he),空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)器中電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)(de)壁(bi)溫(wen)將(jiang)(jiang)呈(cheng)直線變化,如果(guo)(guo)表面(mian)負(fu)(fu)荷(he)(he)增大,電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)(de)壁(bi)溫(wen)將(jiang)(jiang)增大,這將(jiang)(jiang)降(jiang)低(di)(di)(di)空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)器中電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)(de)使用壽命,但是如果(guo)(guo)表面(mian)負(fu)(fu)荷(he)(he)過(guo)小,壁(bi)溫(wen)過(guo)低(di)(di)(di),空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)器換熱(re)(re)器的(de)(de)效率又降(jiang)低(di)(di)(di)了,所以(yi)空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)器中電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)(de)表面(mian)負(fu)(fu)荷(he)(he)的(de)(de)選擇比較重(zhong)要。
3.空(kong)氣(qi)加(jia)(jia)熱(re)(re)器中(zhong)(zhong)空(kong)氣(qi)終溫T2提(ti)高時(shi),由于空(kong)氣(qi)粘性增加(jia)(jia),氣(qi)體雷諾數減小,使得(de)對流(liu)換熱(re)(re)強度(du)降低,空(kong)氣(qi)加(jia)(jia)熱(re)(re)器中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)(jian)的表(biao)面溫度(du)同時(shi)上(shang)升(sheng)(sheng),紅外碳硫分析儀使得(de)散熱(re)(re)損(sun)失增加(jia)(jia),從而降低換熱(re)(re)器的效率(lv)。當T2提(ti)高過(guo)大(da)時(shi),電(dian)熱(re)(re)元件(jian)(jian)表(biao)面的溫度(du)亦會大(da)大(da)升(sheng)(sheng)高,致使一般(ban)電(dian)熱(re)(re)元件(jian)(jian)無法承(cheng)受,故T2的增加(jia)(jia)通常受到空(kong)氣(qi)加(jia)(jia)熱(re)(re)器中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)(jian)材料耐熱(re)(re)性能(neng)的限制。