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)(re)(re),而降低(di)了空氣加熱(re)(re)(re)器內電熱(re)(re)(re)元(yuan)件(jian)表(biao)面溫(wen)度(du),不僅有利于(yu)延長空氣加熱(re)(re)(re)器電熱(re)(re)(re)元(yuan)件(jian)的(de)(de)使(shi)用壽命,而且使(shi)得(de)空氣電加熱(re)(re)(re)器散熱(re)(re)(re)損失(shi)減小(xiao),因而空氣換(huan)熱(re)(re)(re)器的(de)(de)效率提高(gao)(gao)了,但速度(du)如(ru)果(guo)過大,使(shi)得(de)壓(ya)力(li)損失(shi)陡(dou)增(zeng),這將不利于(yu)加熱(re)(re)(re)效率的(de)(de)提高(gao)(gao)。
2.若其它條件(jian)不變(bian),改變(bian)表(biao)面(mian)負(fu)荷,空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)元(yuan)件(jian)的壁(bi)溫將呈直線變(bian)化(hua),如(ru)果表(biao)面(mian)負(fu)荷增大(da),電(dian)熱(re)(re)元(yuan)件(jian)的壁(bi)溫將增大(da),這(zhe)將降低空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)元(yuan)件(jian)的使(shi)用壽(shou)命,但(dan)是如(ru)果表(biao)面(mian)負(fu)荷過小,壁(bi)溫過低,空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)換(huan)熱(re)(re)器(qi)的效率又降低了,所以(yi)空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)元(yuan)件(jian)的表(biao)面(mian)負(fu)荷的選擇比(bi)較重要。
3.空(kong)氣(qi)(qi)加(jia)(jia)熱(re)器中空(kong)氣(qi)(qi)終溫T2提高時(shi),由(you)于空(kong)氣(qi)(qi)粘性(xing)增加(jia)(jia),氣(qi)(qi)體雷(lei)諾(nuo)數減小,使得對流(liu)換熱(re)強度降低,空(kong)氣(qi)(qi)加(jia)(jia)熱(re)器中電熱(re)元件(jian)(jian)的(de)表(biao)面溫度同時(shi)上升,紅(hong)外(wai)碳(tan)硫(liu)分析(xi)儀使得散熱(re)損失增加(jia)(jia),從而降低換熱(re)器的(de)效率。當T2提高過大(da)時(shi),電熱(re)元件(jian)(jian)表(biao)面的(de)溫度亦會大(da)大(da)升高,致使一般電熱(re)元件(jian)(jian)無法承(cheng)受,故T2的(de)增加(jia)(jia)通常受到空(kong)氣(qi)(qi)加(jia)(jia)熱(re)器中電熱(re)元件(jian)(jian)材料耐熱(re)性(xing)能(neng)的(de)限(xian)制。