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(er)降低了空(kong)(kong)氣加(jia)熱(re)器(qi)(qi)內(nei)電熱(re)元(yuan)件(jian)表面溫度,不僅(jin)有利于延長空(kong)(kong)氣加(jia)熱(re)器(qi)(qi)電熱(re)元(yuan)件(jian)的使(shi)用壽命(ming),而(er)且使(shi)得空(kong)(kong)氣電加(jia)熱(re)器(qi)(qi)散熱(re)損失減小,因(yin)而(er)空(kong)(kong)氣換熱(re)器(qi)(qi)的效(xiao)率提(ti)高了,但速度如果過大,使(shi)得壓力損失陡增,這(zhe)將不利于加(jia)熱(re)效(xiao)率的提(ti)高。
2.若其它條件不(bu)變(bian),改變(bian)表面(mian)負(fu)荷,空氣加熱(re)(re)器中電(dian)熱(re)(re)元(yuan)(yuan)件的(de)壁(bi)溫(wen)將呈直線變(bian)化(hua),如(ru)(ru)果表面(mian)負(fu)荷增(zeng)大(da),電(dian)熱(re)(re)元(yuan)(yuan)件的(de)壁(bi)溫(wen)將增(zeng)大(da),這將降(jiang)低空氣加熱(re)(re)器中電(dian)熱(re)(re)元(yuan)(yuan)件的(de)使用壽命,但是(shi)如(ru)(ru)果表面(mian)負(fu)荷過小(xiao),壁(bi)溫(wen)過低,空氣加熱(re)(re)器換熱(re)(re)器的(de)效率又降(jiang)低了,所以空氣加熱(re)(re)器中電(dian)熱(re)(re)元(yuan)(yuan)件的(de)表面(mian)負(fu)荷的(de)選擇(ze)比(bi)較重要。
3.空氣(qi)(qi)(qi)(qi)加(jia)熱(re)器(qi)中(zhong)(zhong)空氣(qi)(qi)(qi)(qi)終溫T2提高時(shi),由(you)于空氣(qi)(qi)(qi)(qi)粘性(xing)增加(jia),氣(qi)(qi)(qi)(qi)體雷諾(nuo)數減小,使(shi)得(de)(de)對流換熱(re)強度降低,空氣(qi)(qi)(qi)(qi)加(jia)熱(re)器(qi)中(zhong)(zhong)電(dian)(dian)熱(re)元(yuan)件(jian)(jian)的(de)表(biao)面溫度同(tong)時(shi)上升,紅外(wai)碳硫分析儀使(shi)得(de)(de)散熱(re)損失增加(jia),從(cong)而降低換熱(re)器(qi)的(de)效率。當T2提高過大(da)時(shi),電(dian)(dian)熱(re)元(yuan)件(jian)(jian)表(biao)面的(de)溫度亦會大(da)大(da)升高,致使(shi)一般電(dian)(dian)熱(re)元(yuan)件(jian)(jian)無法承(cheng)受(shou)(shou),故T2的(de)增加(jia)通常受(shou)(shou)到空氣(qi)(qi)(qi)(qi)加(jia)熱(re)器(qi)中(zhong)(zhong)電(dian)(dian)熱(re)元(yuan)件(jian)(jian)材料耐熱(re)性(xing)能的(de)限制(zhi)。