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(dui)流換熱(re)(re),而降低(di)了空氣加熱(re)(re)器內電熱(re)(re)元(yuan)件(jian)表(biao)面溫度,不僅有利于(yu)延長(chang)空氣加熱(re)(re)器電熱(re)(re)元(yuan)件(jian)的(de)使(shi)用(yong)壽命,而且(qie)使(shi)得(de)(de)空氣電加熱(re)(re)器散熱(re)(re)損(sun)失(shi)減(jian)小,因而空氣換熱(re)(re)器的(de)效率(lv)提(ti)高(gao)了,但速度如果過大(da),使(shi)得(de)(de)壓力損(sun)失(shi)陡(dou)增,這將不利于(yu)加熱(re)(re)效率(lv)的(de)提(ti)高(gao)。
2.若其它條件不變(bian),改變(bian)表面負(fu)荷,空氣加(jia)熱(re)(re)(re)(re)(re)器中(zhong)電熱(re)(re)(re)(re)(re)元件的(de)壁溫(wen)將呈直線(xian)變(bian)化,如果表面負(fu)荷增大,電熱(re)(re)(re)(re)(re)元件的(de)壁溫(wen)將增大,這將降低空氣加(jia)熱(re)(re)(re)(re)(re)器中(zhong)電熱(re)(re)(re)(re)(re)元件的(de)使用(yong)壽命,但是如果表面負(fu)荷過(guo)小,壁溫(wen)過(guo)低,空氣加(jia)熱(re)(re)(re)(re)(re)器換熱(re)(re)(re)(re)(re)器的(de)效率又降低了,所(suo)以空氣加(jia)熱(re)(re)(re)(re)(re)器中(zhong)電熱(re)(re)(re)(re)(re)元件的(de)表面負(fu)荷的(de)選擇比較(jiao)重要。
3.空(kong)(kong)(kong)氣(qi)(qi)加(jia)熱(re)器(qi)中(zhong)(zhong)空(kong)(kong)(kong)氣(qi)(qi)終溫(wen)T2提高時,由(you)于(yu)空(kong)(kong)(kong)氣(qi)(qi)粘(zhan)性增(zeng)加(jia),氣(qi)(qi)體雷諾數減小,使得對流換熱(re)強度降(jiang)低(di),空(kong)(kong)(kong)氣(qi)(qi)加(jia)熱(re)器(qi)中(zhong)(zhong)電(dian)熱(re)元(yuan)(yuan)件(jian)的表(biao)(biao)面溫(wen)度同時上升(sheng),紅外碳硫分析(xi)儀使得散熱(re)損失增(zeng)加(jia),從而降(jiang)低(di)換熱(re)器(qi)的效率。當T2提高過大(da)時,電(dian)熱(re)元(yuan)(yuan)件(jian)表(biao)(biao)面的溫(wen)度亦會(hui)大(da)大(da)升(sheng)高,致(zhi)使一般電(dian)熱(re)元(yuan)(yuan)件(jian)無法承受(shou),故T2的增(zeng)加(jia)通常受(shou)到空(kong)(kong)(kong)氣(qi)(qi)加(jia)熱(re)器(qi)中(zhong)(zhong)電(dian)熱(re)元(yuan)(yuan)件(jian)材料耐(nai)熱(re)性能(neng)的限(xian)制。