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),而降低了空(kong)(kong)(kong)氣加熱(re)(re)器(qi)(qi)內電(dian)熱(re)(re)元件表面溫度,不僅有利(li)于延長空(kong)(kong)(kong)氣加熱(re)(re)器(qi)(qi)電(dian)熱(re)(re)元件的(de)使(shi)(shi)用壽(shou)命,而且使(shi)(shi)得(de)空(kong)(kong)(kong)氣電(dian)加熱(re)(re)器(qi)(qi)散熱(re)(re)損失減小(xiao),因而空(kong)(kong)(kong)氣換熱(re)(re)器(qi)(qi)的(de)效(xiao)率提(ti)高了,但速度如果過(guo)大,使(shi)(shi)得(de)壓力損失陡增,這將(jiang)不利(li)于加熱(re)(re)效(xiao)率的(de)提(ti)高。
2.若(ruo)其它(ta)條(tiao)件(jian)不變,改變表面負(fu)荷,空(kong)氣加熱(re)器(qi)(qi)中電(dian)熱(re)元(yuan)件(jian)的(de)壁(bi)溫將(jiang)呈直線(xian)變化,如(ru)果表面負(fu)荷增(zeng)大,電(dian)熱(re)元(yuan)件(jian)的(de)壁(bi)溫將(jiang)增(zeng)大,這(zhe)將(jiang)降低(di)空(kong)氣加熱(re)器(qi)(qi)中電(dian)熱(re)元(yuan)件(jian)的(de)使(shi)用壽命,但(dan)是如(ru)果表面負(fu)荷過小,壁(bi)溫過低(di),空(kong)氣加熱(re)器(qi)(qi)換熱(re)器(qi)(qi)的(de)效率又降低(di)了,所以空(kong)氣加熱(re)器(qi)(qi)中電(dian)熱(re)元(yuan)件(jian)的(de)表面負(fu)荷的(de)選(xuan)擇比較重要。
3.空(kong)氣加(jia)熱(re)(re)(re)(re)器中(zhong)(zhong)空(kong)氣終溫(wen)T2提高時(shi),由于空(kong)氣粘性(xing)增(zeng)加(jia),氣體雷諾數減小,使得對流換熱(re)(re)(re)(re)強度降低,空(kong)氣加(jia)熱(re)(re)(re)(re)器中(zhong)(zhong)電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)的(de)表(biao)面溫(wen)度同時(shi)上升(sheng),紅外碳(tan)硫分析(xi)儀使得散熱(re)(re)(re)(re)損失(shi)增(zeng)加(jia),從而降低換熱(re)(re)(re)(re)器的(de)效率(lv)。當T2提高過大時(shi),電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)表(biao)面的(de)溫(wen)度亦會(hui)大大升(sheng)高,致使一般電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)無法承受,故(gu)T2的(de)增(zeng)加(jia)通(tong)常受到空(kong)氣加(jia)熱(re)(re)(re)(re)器中(zhong)(zhong)電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)材料耐(nai)熱(re)(re)(re)(re)性(xing)能的(de)限制。