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(huan)熱(re),而(er)降低了空(kong)(kong)氣(qi)(qi)(qi)加(jia)(jia)熱(re)器(qi)內電(dian)熱(re)元件表面溫(wen)度(du),不僅有(you)利(li)于延長空(kong)(kong)氣(qi)(qi)(qi)加(jia)(jia)熱(re)器(qi)電(dian)熱(re)元件的(de)使用壽(shou)命,而(er)且使得(de)空(kong)(kong)氣(qi)(qi)(qi)電(dian)加(jia)(jia)熱(re)器(qi)散熱(re)損失減小,因而(er)空(kong)(kong)氣(qi)(qi)(qi)換(huan)熱(re)器(qi)的(de)效率(lv)提高(gao)了,但(dan)速度(du)如果(guo)過大,使得(de)壓力損失陡增(zeng),這將(jiang)不利(li)于加(jia)(jia)熱(re)效率(lv)的(de)提高(gao)。
2.若其它(ta)條件不變(bian),改(gai)變(bian)表面負荷(he)(he),空(kong)氣加熱(re)(re)(re)器(qi)中電(dian)熱(re)(re)(re)元(yuan)件的壁溫(wen)將呈直線(xian)變(bian)化,如果(guo)表面負荷(he)(he)增大(da),電(dian)熱(re)(re)(re)元(yuan)件的壁溫(wen)將增大(da),這將降低(di)空(kong)氣加熱(re)(re)(re)器(qi)中電(dian)熱(re)(re)(re)元(yuan)件的使用壽(shou)命,但是如果(guo)表面負荷(he)(he)過(guo)(guo)小,壁溫(wen)過(guo)(guo)低(di),空(kong)氣加熱(re)(re)(re)器(qi)換(huan)熱(re)(re)(re)器(qi)的效率又降低(di)了,所以(yi)空(kong)氣加熱(re)(re)(re)器(qi)中電(dian)熱(re)(re)(re)元(yuan)件的表面負荷(he)(he)的選擇比較重要。
3.空氣(qi)加熱(re)(re)(re)(re)器中空氣(qi)終溫T2提高(gao)時(shi),由于(yu)空氣(qi)粘性增(zeng)加,氣(qi)體雷(lei)諾數減(jian)小(xiao),使得對流換(huan)熱(re)(re)(re)(re)強度(du)(du)降(jiang)(jiang)低,空氣(qi)加熱(re)(re)(re)(re)器中電(dian)(dian)熱(re)(re)(re)(re)元(yuan)件(jian)(jian)的表(biao)面(mian)(mian)溫度(du)(du)同時(shi)上升,紅外碳硫分析(xi)儀使得散熱(re)(re)(re)(re)損失增(zeng)加,從而降(jiang)(jiang)低換(huan)熱(re)(re)(re)(re)器的效率(lv)。當(dang)T2提高(gao)過大(da)時(shi),電(dian)(dian)熱(re)(re)(re)(re)元(yuan)件(jian)(jian)表(biao)面(mian)(mian)的溫度(du)(du)亦會大(da)大(da)升高(gao),致使一般電(dian)(dian)熱(re)(re)(re)(re)元(yuan)件(jian)(jian)無法承受,故T2的增(zeng)加通常受到空氣(qi)加熱(re)(re)(re)(re)器中電(dian)(dian)熱(re)(re)(re)(re)元(yuan)件(jian)(jian)材料耐熱(re)(re)(re)(re)性能(neng)的限制(zhi)。