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),而降(jiang)低(di)了(le)(le)空(kong)氣加(jia)(jia)熱(re)(re)器(qi)(qi)內電熱(re)(re)元件(jian)表面溫(wen)度,不(bu)僅有利于延(yan)長空(kong)氣加(jia)(jia)熱(re)(re)器(qi)(qi)電熱(re)(re)元件(jian)的使(shi)用壽命,而且使(shi)得空(kong)氣電加(jia)(jia)熱(re)(re)器(qi)(qi)散熱(re)(re)損失減小,因而空(kong)氣換熱(re)(re)器(qi)(qi)的效率提高(gao)了(le)(le),但速(su)度如果過大,使(shi)得壓力損失陡增(zeng),這將不(bu)利于加(jia)(jia)熱(re)(re)效率的提高(gao)。
2.若其它條件(jian)(jian)(jian)不變,改變表(biao)(biao)面(mian)負(fu)荷(he)(he),空(kong)氣加(jia)熱(re)(re)器(qi)中電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)壁溫將(jiang)呈直線(xian)變化(hua),如果表(biao)(biao)面(mian)負(fu)荷(he)(he)增大(da)(da),電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)壁溫將(jiang)增大(da)(da),這將(jiang)降低(di)空(kong)氣加(jia)熱(re)(re)器(qi)中電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)使用壽命,但是如果表(biao)(biao)面(mian)負(fu)荷(he)(he)過小,壁溫過低(di),空(kong)氣加(jia)熱(re)(re)器(qi)換(huan)熱(re)(re)器(qi)的(de)效率又降低(di)了,所以空(kong)氣加(jia)熱(re)(re)器(qi)中電熱(re)(re)元(yuan)件(jian)(jian)(jian)的(de)表(biao)(biao)面(mian)負(fu)荷(he)(he)的(de)選擇比較重要。
3.空氣(qi)加(jia)熱(re)(re)(re)(re)(re)器(qi)(qi)(qi)中(zhong)空氣(qi)終溫(wen)(wen)T2提高時(shi),由于空氣(qi)粘性增加(jia),氣(qi)體雷諾數減小,使得對流換熱(re)(re)(re)(re)(re)強度(du)(du)降(jiang)低(di),空氣(qi)加(jia)熱(re)(re)(re)(re)(re)器(qi)(qi)(qi)中(zhong)電熱(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)的表面溫(wen)(wen)度(du)(du)同時(shi)上升(sheng)(sheng),紅外(wai)碳硫分(fen)析儀(yi)使得散熱(re)(re)(re)(re)(re)損失增加(jia),從(cong)而(er)降(jiang)低(di)換熱(re)(re)(re)(re)(re)器(qi)(qi)(qi)的效率(lv)。當T2提高過大時(shi),電熱(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)表面的溫(wen)(wen)度(du)(du)亦會大大升(sheng)(sheng)高,致使一般電熱(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)無法承受,故T2的增加(jia)通(tong)常受到空氣(qi)加(jia)熱(re)(re)(re)(re)(re)器(qi)(qi)(qi)中(zhong)電熱(re)(re)(re)(re)(re)元(yuan)(yuan)件(jian)材料耐(nai)熱(re)(re)(re)(re)(re)性能(neng)的限(xian)制(zhi)。