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(liu)換(huan)熱(re),而降低(di)了空(kong)(kong)氣加(jia)熱(re)器(qi)內(nei)電熱(re)元件表(biao)面溫度(du),不僅有利于(yu)延(yan)長空(kong)(kong)氣加(jia)熱(re)器(qi)電熱(re)元件的使(shi)用壽(shou)命,而且使(shi)得(de)空(kong)(kong)氣電加(jia)熱(re)器(qi)散(san)熱(re)損失(shi)(shi)減小(xiao),因(yin)而空(kong)(kong)氣換(huan)熱(re)器(qi)的效率提高了,但速度(du)如果過大,使(shi)得(de)壓力損失(shi)(shi)陡(dou)增,這將不利于(yu)加(jia)熱(re)效率的提高。
2.若其它條件不變,改變表(biao)面負荷,空(kong)(kong)氣加熱(re)(re)(re)器中電熱(re)(re)(re)元件的壁溫(wen)(wen)將(jiang)呈直線(xian)變化,如果表(biao)面負荷增大,電熱(re)(re)(re)元件的壁溫(wen)(wen)將(jiang)增大,這將(jiang)降低(di)空(kong)(kong)氣加熱(re)(re)(re)器中電熱(re)(re)(re)元件的使(shi)用壽命,但是如果表(biao)面負荷過小,壁溫(wen)(wen)過低(di),空(kong)(kong)氣加熱(re)(re)(re)器換熱(re)(re)(re)器的效率又降低(di)了(le),所以空(kong)(kong)氣加熱(re)(re)(re)器中電熱(re)(re)(re)元件的表(biao)面負荷的選(xuan)擇比較重要。
3.空(kong)氣(qi)(qi)加熱(re)(re)器(qi)中空(kong)氣(qi)(qi)終溫T2提(ti)高(gao)時,由于(yu)空(kong)氣(qi)(qi)粘(zhan)性增(zeng)加,氣(qi)(qi)體雷諾數減小,使(shi)(shi)得對流換熱(re)(re)強(qiang)度降低,空(kong)氣(qi)(qi)加熱(re)(re)器(qi)中電(dian)(dian)(dian)熱(re)(re)元件(jian)的表面溫度同時上升,紅外碳硫分析儀(yi)使(shi)(shi)得散熱(re)(re)損失增(zeng)加,從(cong)而降低換熱(re)(re)器(qi)的效(xiao)率。當T2提(ti)高(gao)過大(da)(da)時,電(dian)(dian)(dian)熱(re)(re)元件(jian)表面的溫度亦會大(da)(da)大(da)(da)升高(gao),致使(shi)(shi)一般(ban)電(dian)(dian)(dian)熱(re)(re)元件(jian)無法承(cheng)受,故T2的增(zeng)加通(tong)常受到空(kong)氣(qi)(qi)加熱(re)(re)器(qi)中電(dian)(dian)(dian)熱(re)(re)元件(jian)材料耐熱(re)(re)性能的限制。