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)(re)，而降低了空氣(qi)加熱(re)(re)(re)器(qi)(qi)(qi)內電(dian)熱(re)(re)(re)元件(jian)(jian)表面溫度(du)，不(bu)僅有利(li)(li)于延(yan)長空氣(qi)加熱(re)(re)(re)器(qi)(qi)(qi)電(dian)熱(re)(re)(re)元件(jian)(jian)的使(shi)(shi)用(yong)壽命，而且使(shi)(shi)得(de)空氣(qi)電(dian)加熱(re)(re)(re)器(qi)(qi)(qi)散熱(re)(re)(re)損失減小，因而空氣(qi)換熱(re)(re)(re)器(qi)(qi)(qi)的效率(lv)提(ti)高了，但速度(du)如(ru)果過大，使(shi)(shi)得(de)壓力損失陡增，這將不(bu)利(li)(li)于加熱(re)(re)(re)效率(lv)的提(ti)高。

     2.若其它條件(jian)(jian)不變(bian)，改(gai)變(bian)表面(mian)(mian)(mian)負荷(he)(he)，空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)(jian)的壁溫將(jiang)呈直線(xian)變(bian)化(hua)，如果(guo)表面(mian)(mian)(mian)負荷(he)(he)增(zeng)大，電(dian)熱(re)(re)元件(jian)(jian)的壁溫將(jiang)增(zeng)大，這將(jiang)降低(di)(di)空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)(jian)的使用壽命，但是如果(guo)表面(mian)(mian)(mian)負荷(he)(he)過小，壁溫過低(di)(di)，空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)換熱(re)(re)器(qi)(qi)的效率又降低(di)(di)了，所(suo)以空(kong)(kong)氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)(jian)的表面(mian)(mian)(mian)負荷(he)(he)的選擇比(bi)較(jiao)重要。

     3.空(kong)(kong)氣(qi)加(jia)熱器中空(kong)(kong)氣(qi)終溫T2提(ti)(ti)高時(shi)，由(you)于空(kong)(kong)氣(qi)粘性(xing)增(zeng)加(jia)，氣(qi)體(ti)雷諾數(shu)減(jian)小，使(shi)得(de)對流(liu)換(huan)熱強(qiang)度降(jiang)低，空(kong)(kong)氣(qi)加(jia)熱器中電熱元(yuan)件(jian)的表面(mian)(mian)溫度同時(shi)上升(sheng)，紅外碳(tan)硫分(fen)析儀使(shi)得(de)散(san)熱損(sun)失增(zeng)加(jia)，從而(er)降(jiang)低換(huan)熱器的效率。當(dang)T2提(ti)(ti)高過(guo)大時(shi)，電熱元(yuan)件(jian)表面(mian)(mian)的溫度亦會大大升(sheng)高，致(zhi)使(shi)一般電熱元(yuan)件(jian)無法承受，故T2的增(zeng)加(jia)通(tong)常受到(dao)空(kong)(kong)氣(qi)加(jia)熱器中電熱元(yuan)件(jian)材料耐(nai)熱性(xing)能的限制(zhi)。