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)流換熱(re)(re),而(er)降低了空(kong)氣(qi)加熱(re)(re)器(qi)內電熱(re)(re)元(yuan)件表面溫度(du),不僅有(you)利(li)于延長空(kong)氣(qi)加熱(re)(re)器(qi)電熱(re)(re)元(yuan)件的(de)使用壽命,而(er)且使得空(kong)氣(qi)電加熱(re)(re)器(qi)散熱(re)(re)損失減小,因而(er)空(kong)氣(qi)換熱(re)(re)器(qi)的(de)效(xiao)率提(ti)高了,但速度(du)如果過大(da),使得壓力損失陡增,這將不利(li)于加熱(re)(re)效(xiao)率的(de)提(ti)高。
2.若其它條件(jian)不變(bian)(bian),改變(bian)(bian)表(biao)面負(fu)荷,空氣(qi)加(jia)熱(re)(re)器中(zhong)電熱(re)(re)元件(jian)的壁(bi)溫(wen)(wen)將(jiang)(jiang)呈直(zhi)線變(bian)(bian)化,如果(guo)表(biao)面負(fu)荷增(zeng)大,電熱(re)(re)元件(jian)的壁(bi)溫(wen)(wen)將(jiang)(jiang)增(zeng)大,這(zhe)將(jiang)(jiang)降(jiang)低(di)空氣(qi)加(jia)熱(re)(re)器中(zhong)電熱(re)(re)元件(jian)的使用壽命,但是如果(guo)表(biao)面負(fu)荷過小,壁(bi)溫(wen)(wen)過低(di),空氣(qi)加(jia)熱(re)(re)器換(huan)熱(re)(re)器的效率(lv)又降(jiang)低(di)了(le),所以(yi)空氣(qi)加(jia)熱(re)(re)器中(zhong)電熱(re)(re)元件(jian)的表(biao)面負(fu)荷的選擇比較(jiao)重要。
3.空(kong)氣加(jia)熱(re)(re)(re)器(qi)中空(kong)氣終溫T2提高(gao)(gao)時(shi)(shi),由(you)于(yu)空(kong)氣粘(zhan)性(xing)增(zeng)加(jia),氣體雷諾(nuo)數減小,使得(de)(de)對(dui)流換熱(re)(re)(re)強度(du)(du)降低,空(kong)氣加(jia)熱(re)(re)(re)器(qi)中電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)的(de)(de)表面(mian)溫度(du)(du)同(tong)時(shi)(shi)上升(sheng),紅(hong)外碳硫分析儀使得(de)(de)散熱(re)(re)(re)損失增(zeng)加(jia),從而降低換熱(re)(re)(re)器(qi)的(de)(de)效率。當(dang)T2提高(gao)(gao)過大時(shi)(shi),電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)表面(mian)的(de)(de)溫度(du)(du)亦會(hui)大大升(sheng)高(gao)(gao),致(zhi)使一般(ban)電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)無法(fa)承(cheng)受,故T2的(de)(de)增(zeng)加(jia)通常受到空(kong)氣加(jia)熱(re)(re)(re)器(qi)中電(dian)(dian)熱(re)(re)(re)元(yuan)件(jian)(jian)材料耐(nai)熱(re)(re)(re)性(xing)能的(de)(de)限(xian)制。