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)(re),而(er)降(jiang)低(di)了(le)空氣(qi)(qi)加熱(re)(re)(re)(re)器內電(dian)(dian)(dian)熱(re)(re)(re)(re)元(yuan)件表面(mian)溫度,不僅有利于延長空氣(qi)(qi)加熱(re)(re)(re)(re)器電(dian)(dian)(dian)熱(re)(re)(re)(re)元(yuan)件的(de)使(shi)(shi)用(yong)壽命,而(er)且(qie)使(shi)(shi)得空氣(qi)(qi)電(dian)(dian)(dian)加熱(re)(re)(re)(re)器散熱(re)(re)(re)(re)損失減小,因而(er)空氣(qi)(qi)換熱(re)(re)(re)(re)器的(de)效(xiao)(xiao)率(lv)提(ti)高了(le),但(dan)速度如果過大,使(shi)(shi)得壓力損失陡(dou)增(zeng),這將不利于加熱(re)(re)(re)(re)效(xiao)(xiao)率(lv)的(de)提(ti)高。
2.若(ruo)其它條件不變,改變表(biao)(biao)面(mian)負荷(he),空氣加熱(re)(re)器(qi)中電熱(re)(re)元(yuan)件的壁溫(wen)將呈直線變化,如果表(biao)(biao)面(mian)負荷(he)增大,電熱(re)(re)元(yuan)件的壁溫(wen)將增大,這將降低空氣加熱(re)(re)器(qi)中電熱(re)(re)元(yuan)件的使(shi)用壽命,但是如果表(biao)(biao)面(mian)負荷(he)過(guo)(guo)小,壁溫(wen)過(guo)(guo)低,空氣加熱(re)(re)器(qi)換熱(re)(re)器(qi)的效率(lv)又降低了,所以(yi)空氣加熱(re)(re)器(qi)中電熱(re)(re)元(yuan)件的表(biao)(biao)面(mian)負荷(he)的選擇比較重要。
3.空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器中空(kong)(kong)氣(qi)終溫(wen)T2提(ti)高時,由(you)于空(kong)(kong)氣(qi)粘性(xing)增(zeng)(zeng)加(jia)(jia),氣(qi)體雷諾數減小(xiao),使(shi)(shi)得(de)對流換熱(re)強(qiang)度(du)降(jiang)低(di),空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器中電熱(re)元(yuan)(yuan)件(jian)的表面溫(wen)度(du)同(tong)時上升(sheng),紅外碳(tan)硫分析(xi)儀使(shi)(shi)得(de)散熱(re)損失(shi)增(zeng)(zeng)加(jia)(jia),從而降(jiang)低(di)換熱(re)器的效(xiao)率。當T2提(ti)高過大(da)時,電熱(re)元(yuan)(yuan)件(jian)表面的溫(wen)度(du)亦會(hui)大(da)大(da)升(sheng)高,致使(shi)(shi)一(yi)般電熱(re)元(yuan)(yuan)件(jian)無法承受(shou),故T2的增(zeng)(zeng)加(jia)(jia)通常受(shou)到空(kong)(kong)氣(qi)加(jia)(jia)熱(re)器中電熱(re)元(yuan)(yuan)件(jian)材料(liao)耐(nai)熱(re)性(xing)能(neng)的限制(zhi)。