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),而降低了空(kong)氣(qi)加(jia)熱(re)(re)器(qi)內(nei)電熱(re)(re)元件表面(mian)溫度(du),不(bu)僅有(you)利(li)于(yu)延長空(kong)氣(qi)加(jia)熱(re)(re)器(qi)電熱(re)(re)元件的(de)使用(yong)壽命,而且使得空(kong)氣(qi)電加(jia)熱(re)(re)器(qi)散熱(re)(re)損失(shi)減小(xiao),因而空(kong)氣(qi)換熱(re)(re)器(qi)的(de)效(xiao)率(lv)提高了,但速(su)度(du)如(ru)果過大,使得壓力(li)損失(shi)陡增(zeng),這將不(bu)利(li)于(yu)加(jia)熱(re)(re)效(xiao)率(lv)的(de)提高。
2.若其(qi)它條件(jian)不變,改變表(biao)面(mian)負荷(he),空氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)的(de)壁(bi)溫(wen)將(jiang)呈直(zhi)線變化,如果(guo)表(biao)面(mian)負荷(he)增大(da),電(dian)熱(re)(re)元件(jian)的(de)壁(bi)溫(wen)將(jiang)增大(da),這將(jiang)降低空氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)的(de)使(shi)用壽命,但是(shi)如果(guo)表(biao)面(mian)負荷(he)過小,壁(bi)溫(wen)過低,空氣(qi)加(jia)熱(re)(re)器(qi)(qi)換熱(re)(re)器(qi)(qi)的(de)效率又降低了,所以(yi)空氣(qi)加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元件(jian)的(de)表(biao)面(mian)負荷(he)的(de)選擇比(bi)較重要(yao)。
3.空(kong)(kong)氣加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)空(kong)(kong)氣終溫T2提高時(shi),由于空(kong)(kong)氣粘性(xing)增(zeng)加(jia),氣體雷諾數減小,使(shi)得對流換(huan)熱(re)(re)強(qiang)度(du)降低(di),空(kong)(kong)氣加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元(yuan)(yuan)件(jian)的(de)表面溫度(du)同時(shi)上升,紅外碳硫分析儀(yi)使(shi)得散熱(re)(re)損失增(zeng)加(jia),從(cong)而降低(di)換(huan)熱(re)(re)器(qi)(qi)的(de)效率(lv)。當T2提高過大(da)(da)時(shi),電(dian)熱(re)(re)元(yuan)(yuan)件(jian)表面的(de)溫度(du)亦會大(da)(da)大(da)(da)升高,致使(shi)一(yi)般電(dian)熱(re)(re)元(yuan)(yuan)件(jian)無法承受(shou),故T2的(de)增(zeng)加(jia)通常受(shou)到空(kong)(kong)氣加(jia)熱(re)(re)器(qi)(qi)中(zhong)(zhong)電(dian)熱(re)(re)元(yuan)(yuan)件(jian)材料(liao)耐熱(re)(re)性(xing)能的(de)限制。