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)氣(qi)加(jia)(jia)熱(re)(re)器(qi)內電熱(re)(re)元件(jian)表面溫度,不僅有利(li)于(yu)延長空(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)器(qi)電熱(re)(re)元件(jian)的使(shi)(shi)用壽命,而且使(shi)(shi)得空(kong)(kong)氣(qi)電加(jia)(jia)熱(re)(re)器(qi)散熱(re)(re)損(sun)失(shi)減小,因而空(kong)(kong)氣(qi)換熱(re)(re)器(qi)的效(xiao)率(lv)(lv)提高(gao)了,但(dan)速度如(ru)果過大,使(shi)(shi)得壓(ya)力(li)損(sun)失(shi)陡增,這將不利(li)于(yu)加(jia)(jia)熱(re)(re)效(xiao)率(lv)(lv)的提高(gao)。
2.若其(qi)它條件(jian)不變(bian),改(gai)變(bian)表面負(fu)(fu)荷,空(kong)氣(qi)加熱(re)器中(zhong)電(dian)熱(re)元件(jian)的(de)壁(bi)溫(wen)將呈直(zhi)線(xian)變(bian)化,如果表面負(fu)(fu)荷增(zeng)大,電(dian)熱(re)元件(jian)的(de)壁(bi)溫(wen)將增(zeng)大,這將降低空(kong)氣(qi)加熱(re)器中(zhong)電(dian)熱(re)元件(jian)的(de)使用壽命,但(dan)是如果表面負(fu)(fu)荷過小,壁(bi)溫(wen)過低,空(kong)氣(qi)加熱(re)器換(huan)熱(re)器的(de)效率又降低了,所以空(kong)氣(qi)加熱(re)器中(zhong)電(dian)熱(re)元件(jian)的(de)表面負(fu)(fu)荷的(de)選(xuan)擇比較重要。
3.空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)空(kong)氣(qi)(qi)終溫T2提高時(shi),由(you)于空(kong)氣(qi)(qi)粘(zhan)性增加(jia),氣(qi)(qi)體雷諾數減小(xiao),使(shi)(shi)得對流換熱(re)(re)(re)強度(du)(du)降低,空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)(yuan)件(jian)的(de)(de)表(biao)面溫度(du)(du)同時(shi)上升(sheng),紅外碳(tan)硫分析儀使(shi)(shi)得散熱(re)(re)(re)損失增加(jia),從(cong)而降低換熱(re)(re)(re)器(qi)的(de)(de)效率。當T2提高過大時(shi),電(dian)熱(re)(re)(re)元(yuan)(yuan)件(jian)表(biao)面的(de)(de)溫度(du)(du)亦會大大升(sheng)高,致(zhi)使(shi)(shi)一般(ban)電(dian)熱(re)(re)(re)元(yuan)(yuan)件(jian)無法承受,故(gu)T2的(de)(de)增加(jia)通常受到空(kong)氣(qi)(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)(yuan)件(jian)材料耐熱(re)(re)(re)性能的(de)(de)限制(zhi)。