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(di)了(le)空(kong)氣(qi)加(jia)熱(re)(re)器內電(dian)(dian)熱(re)(re)元件表(biao)面(mian)溫度(du),不僅有(you)利于延(yan)長(chang)空(kong)氣(qi)加(jia)熱(re)(re)器電(dian)(dian)熱(re)(re)元件的使(shi)用壽命,而且(qie)使(shi)得(de)空(kong)氣(qi)電(dian)(dian)加(jia)熱(re)(re)器散熱(re)(re)損失(shi)減小,因而空(kong)氣(qi)換熱(re)(re)器的效率提高(gao)了(le),但速度(du)如果(guo)過大(da),使(shi)得(de)壓力損失(shi)陡增(zeng),這將不利于加(jia)熱(re)(re)效率的提高(gao)。
2.若其它(ta)條(tiao)件(jian)不變(bian),改變(bian)表面(mian)(mian)負荷,空氣(qi)加(jia)熱(re)(re)器(qi)中電熱(re)(re)元件(jian)的(de)壁溫將呈直線(xian)變(bian)化,如果表面(mian)(mian)負荷增(zeng)大,電熱(re)(re)元件(jian)的(de)壁溫將增(zeng)大,這將降低(di)空氣(qi)加(jia)熱(re)(re)器(qi)中電熱(re)(re)元件(jian)的(de)使用壽(shou)命,但是如果表面(mian)(mian)負荷過(guo)小(xiao),壁溫過(guo)低(di),空氣(qi)加(jia)熱(re)(re)器(qi)換熱(re)(re)器(qi)的(de)效(xiao)率又降低(di)了,所(suo)以空氣(qi)加(jia)熱(re)(re)器(qi)中電熱(re)(re)元件(jian)的(de)表面(mian)(mian)負荷的(de)選(xuan)擇比較重要。
3.空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)中空(kong)氣(qi)終溫(wen)T2提高(gao)時(shi),由于空(kong)氣(qi)粘性增(zeng)加(jia)(jia),氣(qi)體雷諾(nuo)數減小,使(shi)得對流換熱(re)(re)(re)強度降低,空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)中電熱(re)(re)(re)元件(jian)(jian)的表面溫(wen)度同時(shi)上(shang)升,紅外碳硫分析儀使(shi)得散熱(re)(re)(re)損失(shi)增(zeng)加(jia)(jia),從而降低換熱(re)(re)(re)器(qi)(qi)(qi)的效率(lv)。當(dang)T2提高(gao)過大時(shi),電熱(re)(re)(re)元件(jian)(jian)表面的溫(wen)度亦(yi)會大大升高(gao),致使(shi)一般(ban)電熱(re)(re)(re)元件(jian)(jian)無法(fa)承受(shou),故T2的增(zeng)加(jia)(jia)通常(chang)受(shou)到空(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)(qi)中電熱(re)(re)(re)元件(jian)(jian)材料耐熱(re)(re)(re)性能的限制。