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(dui)流換(huan)(huan)熱(re)(re)(re),而降低了空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)內(nei)電熱(re)(re)(re)元件(jian)表面溫(wen)度,不(bu)僅有(you)利(li)于(yu)延長空(kong)氣(qi)加(jia)熱(re)(re)(re)器(qi)電熱(re)(re)(re)元件(jian)的(de)使用壽命,而且使得(de)空(kong)氣(qi)電加(jia)熱(re)(re)(re)器(qi)散(san)熱(re)(re)(re)損(sun)失減小,因而空(kong)氣(qi)換(huan)(huan)熱(re)(re)(re)器(qi)的(de)效(xiao)率提高了,但速(su)度如果過大,使得(de)壓(ya)力損(sun)失陡增,這將不(bu)利(li)于(yu)加(jia)熱(re)(re)(re)效(xiao)率的(de)提高。
2.若其(qi)它條件不(bu)變,改(gai)變表面負荷,空氣(qi)加熱(re)器(qi)(qi)中(zhong)電(dian)(dian)熱(re)元(yuan)(yuan)件的(de)壁(bi)溫(wen)將(jiang)呈直線變化,如果(guo)表面負荷增大,電(dian)(dian)熱(re)元(yuan)(yuan)件的(de)壁(bi)溫(wen)將(jiang)增大,這將(jiang)降低空氣(qi)加熱(re)器(qi)(qi)中(zhong)電(dian)(dian)熱(re)元(yuan)(yuan)件的(de)使用壽命,但是如果(guo)表面負荷過小,壁(bi)溫(wen)過低,空氣(qi)加熱(re)器(qi)(qi)換(huan)熱(re)器(qi)(qi)的(de)效率(lv)又降低了,所(suo)以(yi)空氣(qi)加熱(re)器(qi)(qi)中(zhong)電(dian)(dian)熱(re)元(yuan)(yuan)件的(de)表面負荷的(de)選擇比較重要。
3.空(kong)(kong)(kong)氣(qi)加(jia)(jia)熱器中空(kong)(kong)(kong)氣(qi)終溫T2提(ti)高時,由于空(kong)(kong)(kong)氣(qi)粘(zhan)性增(zeng)加(jia)(jia),氣(qi)體雷諾數減小,使得(de)對(dui)流換(huan)熱強(qiang)度(du)降(jiang)(jiang)低(di),空(kong)(kong)(kong)氣(qi)加(jia)(jia)熱器中電熱元件(jian)的表面溫度(du)同時上升,紅(hong)外碳(tan)硫分析儀使得(de)散熱損失增(zeng)加(jia)(jia),從而降(jiang)(jiang)低(di)換(huan)熱器的效率。當T2提(ti)高過大時,電熱元件(jian)表面的溫度(du)亦會大大升高,致使一般(ban)電熱元件(jian)無(wu)法承受,故T2的增(zeng)加(jia)(jia)通常(chang)受到空(kong)(kong)(kong)氣(qi)加(jia)(jia)熱器中電熱元件(jian)材料耐熱性能的限制。