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(jiang)低(di)了(le)空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器(qi)內電熱(re)元件表面溫度,不僅有利于(yu)延(yan)長空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器(qi)電熱(re)元件的使(shi)用壽命,而且(qie)使(shi)得空(kong)(kong)氣(qi)電加(jia)(jia)熱(re)器(qi)散熱(re)損失減小,因(yin)而空(kong)(kong)氣(qi)換熱(re)器(qi)的效率提(ti)高了(le),但速度如果過大,使(shi)得壓力損失陡增,這將不利于(yu)加(jia)(jia)熱(re)效率的提(ti)高。
2.若其它條件(jian)(jian)(jian)不變(bian),改變(bian)表(biao)(biao)面(mian)(mian)負(fu)荷,空氣加熱(re)(re)(re)器(qi)(qi)(qi)中電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的(de)壁溫將呈直線變(bian)化,如果表(biao)(biao)面(mian)(mian)負(fu)荷增大,電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的(de)壁溫將增大,這將降(jiang)低空氣加熱(re)(re)(re)器(qi)(qi)(qi)中電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的(de)使用(yong)壽命(ming),但(dan)是如果表(biao)(biao)面(mian)(mian)負(fu)荷過小(xiao),壁溫過低,空氣加熱(re)(re)(re)器(qi)(qi)(qi)換熱(re)(re)(re)器(qi)(qi)(qi)的(de)效率(lv)又降(jiang)低了,所以空氣加熱(re)(re)(re)器(qi)(qi)(qi)中電(dian)熱(re)(re)(re)元件(jian)(jian)(jian)的(de)表(biao)(biao)面(mian)(mian)負(fu)荷的(de)選擇(ze)比(bi)較(jiao)重要。
3.空(kong)(kong)(kong)氣(qi)(qi)加(jia)熱器(qi)中空(kong)(kong)(kong)氣(qi)(qi)終溫T2提(ti)(ti)高時,由于空(kong)(kong)(kong)氣(qi)(qi)粘性(xing)增(zeng)加(jia),氣(qi)(qi)體雷諾(nuo)數減小,使得對(dui)流換熱強度降低(di),空(kong)(kong)(kong)氣(qi)(qi)加(jia)熱器(qi)中電(dian)熱元件的表面(mian)溫度同時上升,紅(hong)外碳(tan)硫分析儀使得散熱損失(shi)增(zeng)加(jia),從而(er)降低(di)換熱器(qi)的效(xiao)率(lv)。當T2提(ti)(ti)高過大(da)時,電(dian)熱元件表面(mian)的溫度亦會大(da)大(da)升高,致使一般電(dian)熱元件無(wu)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)熱器(qi)中電(dian)熱元件材(cai)料耐熱性(xing)能(neng)的限制。