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),而降低(di)了空(kong)氣(qi)(qi)(qi)加熱(re)器內電(dian)熱(re)元件表面溫度,不(bu)僅有利于延長空(kong)氣(qi)(qi)(qi)加熱(re)器電(dian)熱(re)元件的(de)使(shi)用壽(shou)命,而且使(shi)得空(kong)氣(qi)(qi)(qi)電(dian)加熱(re)器散熱(re)損失(shi)減小,因而空(kong)氣(qi)(qi)(qi)換熱(re)器的(de)效率提高(gao)了,但速度如果過大,使(shi)得壓力(li)損失(shi)陡(dou)增,這將不(bu)利于加熱(re)效率的(de)提高(gao)。
2.若其它條件(jian)(jian)不(bu)變,改變表面負荷(he),空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)(de)壁溫(wen)(wen)(wen)將呈直線變化,如(ru)果(guo)表面負荷(he)增(zeng)大(da),電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)(de)壁溫(wen)(wen)(wen)將增(zeng)大(da),這將降低(di)空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)(de)使用壽命,但是(shi)如(ru)果(guo)表面負荷(he)過小,壁溫(wen)(wen)(wen)過低(di),空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)換熱(re)(re)(re)器(qi)的(de)(de)效率(lv)又(you)降低(di)了(le),所以(yi)空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)(de)表面負荷(he)的(de)(de)選(xuan)擇比較重要。
3.空氣(qi)(qi)加(jia)(jia)熱(re)(re)器(qi)中空氣(qi)(qi)終溫(wen)T2提(ti)高(gao)時(shi)(shi),由于空氣(qi)(qi)粘性增(zeng)加(jia)(jia),氣(qi)(qi)體雷諾數減小,使(shi)(shi)得對流(liu)換(huan)熱(re)(re)強度(du)(du)降低,空氣(qi)(qi)加(jia)(jia)熱(re)(re)器(qi)中電(dian)熱(re)(re)元件的(de)表(biao)面(mian)溫(wen)度(du)(du)同時(shi)(shi)上(shang)升,紅(hong)外碳硫分析儀使(shi)(shi)得散熱(re)(re)損(sun)失增(zeng)加(jia)(jia),從而降低換(huan)熱(re)(re)器(qi)的(de)效率。當T2提(ti)高(gao)過大(da)時(shi)(shi),電(dian)熱(re)(re)元件表(biao)面(mian)的(de)溫(wen)度(du)(du)亦會大(da)大(da)升高(gao),致使(shi)(shi)一般電(dian)熱(re)(re)元件無法承受,故T2的(de)增(zeng)加(jia)(jia)通常受到空氣(qi)(qi)加(jia)(jia)熱(re)(re)器(qi)中電(dian)熱(re)(re)元件材料耐熱(re)(re)性能的(de)限(xian)制。