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(liu)換熱(re)(re)(re),而降低(di)了空(kong)(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)內電熱(re)(re)(re)元件表面(mian)溫(wen)度,不僅有利于(yu)延長空(kong)(kong)(kong)氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)(qi)電熱(re)(re)(re)元件的(de)使用壽(shou)命,而且使得(de)空(kong)(kong)(kong)氣(qi)電加(jia)(jia)熱(re)(re)(re)器(qi)(qi)散熱(re)(re)(re)損失減(jian)小(xiao),因而空(kong)(kong)(kong)氣(qi)換熱(re)(re)(re)器(qi)(qi)的(de)效率(lv)提(ti)高了,但速度如(ru)果過大,使得(de)壓力損失陡增,這將不利于(yu)加(jia)(jia)熱(re)(re)(re)效率(lv)的(de)提(ti)高。
2.若(ruo)其它(ta)條件(jian)不變(bian),改變(bian)表(biao)面(mian)負荷,空氣加(jia)熱(re)(re)器(qi)中電熱(re)(re)元件(jian)的(de)(de)壁溫將呈(cheng)直線變(bian)化(hua),如果表(biao)面(mian)負荷增(zeng)大(da),電熱(re)(re)元件(jian)的(de)(de)壁溫將增(zeng)大(da),這將降低空氣加(jia)熱(re)(re)器(qi)中電熱(re)(re)元件(jian)的(de)(de)使用壽命(ming),但(dan)是如果表(biao)面(mian)負荷過小,壁溫過低,空氣加(jia)熱(re)(re)器(qi)換(huan)熱(re)(re)器(qi)的(de)(de)效(xiao)率(lv)又降低了,所(suo)以(yi)空氣加(jia)熱(re)(re)器(qi)中電熱(re)(re)元件(jian)的(de)(de)表(biao)面(mian)負荷的(de)(de)選擇比較重要(yao)。
3.空氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)空氣(qi)終溫(wen)T2提高(gao)(gao)時(shi)(shi),由于空氣(qi)粘性增(zeng)加(jia)(jia),氣(qi)體(ti)雷(lei)諾數減小,使得(de)對(dui)流換熱(re)(re)(re)強度(du)降(jiang)低(di),空氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)(dian)(dian)熱(re)(re)(re)元件(jian)(jian)的表(biao)面溫(wen)度(du)同時(shi)(shi)上升(sheng),紅外碳(tan)硫分析儀(yi)使得(de)散熱(re)(re)(re)損失增(zeng)加(jia)(jia),從而降(jiang)低(di)換熱(re)(re)(re)器(qi)的效率。當T2提高(gao)(gao)過大(da)時(shi)(shi),電(dian)(dian)(dian)熱(re)(re)(re)元件(jian)(jian)表(biao)面的溫(wen)度(du)亦會大(da)大(da)升(sheng)高(gao)(gao),致使一般電(dian)(dian)(dian)熱(re)(re)(re)元件(jian)(jian)無(wu)法承受(shou),故T2的增(zeng)加(jia)(jia)通常受(shou)到空氣(qi)加(jia)(jia)熱(re)(re)(re)器(qi)中(zhong)電(dian)(dian)(dian)熱(re)(re)(re)元件(jian)(jian)材料耐(nai)熱(re)(re)(re)性能的限制(zhi)。