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(dui)流(liu)換熱(re)(re)(re),而(er)降低(di)了空(kong)氣(qi)(qi)加熱(re)(re)(re)器內(nei)電熱(re)(re)(re)元件(jian)表面溫(wen)度(du)(du),不(bu)僅有利于延長空(kong)氣(qi)(qi)加熱(re)(re)(re)器電熱(re)(re)(re)元件(jian)的(de)(de)使(shi)用壽命(ming),而(er)且(qie)使(shi)得空(kong)氣(qi)(qi)電加熱(re)(re)(re)器散熱(re)(re)(re)損失減小,因而(er)空(kong)氣(qi)(qi)換熱(re)(re)(re)器的(de)(de)效率提(ti)高了,但速度(du)(du)如(ru)果過大(da),使(shi)得壓力損失陡增(zeng),這(zhe)將不(bu)利于加熱(re)(re)(re)效率的(de)(de)提(ti)高。
2.若其(qi)它條件不(bu)變,改(gai)變表面(mian)負荷(he),空(kong)氣(qi)加(jia)熱(re)器(qi)(qi)中電(dian)(dian)熱(re)元件的(de)壁溫(wen)將呈直線變化,如(ru)果(guo)表面(mian)負荷(he)增大(da),電(dian)(dian)熱(re)元件的(de)壁溫(wen)將增大(da),這將降(jiang)低(di)(di)空(kong)氣(qi)加(jia)熱(re)器(qi)(qi)中電(dian)(dian)熱(re)元件的(de)使用壽命(ming),但是如(ru)果(guo)表面(mian)負荷(he)過小,壁溫(wen)過低(di)(di),空(kong)氣(qi)加(jia)熱(re)器(qi)(qi)換熱(re)器(qi)(qi)的(de)效率又降(jiang)低(di)(di)了,所以空(kong)氣(qi)加(jia)熱(re)器(qi)(qi)中電(dian)(dian)熱(re)元件的(de)表面(mian)負荷(he)的(de)選擇比較重要。
3.空(kong)(kong)(kong)氣(qi)(qi)加熱(re)器(qi)中(zhong)空(kong)(kong)(kong)氣(qi)(qi)終溫(wen)T2提(ti)高時,由于空(kong)(kong)(kong)氣(qi)(qi)粘性增加,氣(qi)(qi)體雷(lei)諾(nuo)數減(jian)小,使得對流換熱(re)強度降低,空(kong)(kong)(kong)氣(qi)(qi)加熱(re)器(qi)中(zhong)電熱(re)元件(jian)的表(biao)面(mian)溫(wen)度同時上升(sheng),紅外(wai)碳硫分析儀使得散熱(re)損失增加,從而降低換熱(re)器(qi)的效率。當T2提(ti)高過(guo)大時,電熱(re)元件(jian)表(biao)面(mian)的溫(wen)度亦會大大升(sheng)高,致使一般電熱(re)元件(jian)無(wu)法承受(shou),故T2的增加通常受(shou)到空(kong)(kong)(kong)氣(qi)(qi)加熱(re)器(qi)中(zhong)電熱(re)元件(jian)材料(liao)耐熱(re)性能的限制。