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(huan)(huan)熱(re),而降低了(le)空氣(qi)加熱(re)器(qi)內電熱(re)元(yuan)件表面溫度(du),不(bu)僅有利(li)于延長空氣(qi)加熱(re)器(qi)電熱(re)元(yuan)件的使(shi)用(yong)壽命,而且使(shi)得空氣(qi)電加熱(re)器(qi)散熱(re)損(sun)失(shi)減小,因(yin)而空氣(qi)換(huan)(huan)熱(re)器(qi)的效率(lv)提高(gao)了(le),但速度(du)如(ru)果過大,使(shi)得壓(ya)力損(sun)失(shi)陡增,這將(jiang)不(bu)利(li)于加熱(re)效率(lv)的提高(gao)。
2.若其它(ta)條件(jian)(jian)不變(bian),改變(bian)表面(mian)(mian)負荷,空(kong)(kong)氣加(jia)熱(re)器中電熱(re)元件(jian)(jian)的壁(bi)溫(wen)將呈(cheng)直線變(bian)化,如果表面(mian)(mian)負荷增大,電熱(re)元件(jian)(jian)的壁(bi)溫(wen)將增大,這(zhe)將降低(di)(di)空(kong)(kong)氣加(jia)熱(re)器中電熱(re)元件(jian)(jian)的使用壽命,但是如果表面(mian)(mian)負荷過小(xiao),壁(bi)溫(wen)過低(di)(di),空(kong)(kong)氣加(jia)熱(re)器換熱(re)器的效率又降低(di)(di)了,所以(yi)空(kong)(kong)氣加(jia)熱(re)器中電熱(re)元件(jian)(jian)的表面(mian)(mian)負荷的選擇比較(jiao)重要。
3.空氣(qi)(qi)加熱(re)(re)(re)(re)(re)(re)器中(zhong)(zhong)空氣(qi)(qi)終溫(wen)T2提高(gao)時(shi),由于空氣(qi)(qi)粘(zhan)性增(zeng)加,氣(qi)(qi)體(ti)雷諾(nuo)數減小,使(shi)得對流(liu)換熱(re)(re)(re)(re)(re)(re)強(qiang)度(du)降低(di),空氣(qi)(qi)加熱(re)(re)(re)(re)(re)(re)器中(zhong)(zhong)電熱(re)(re)(re)(re)(re)(re)元件(jian)的(de)表面溫(wen)度(du)同時(shi)上升(sheng),紅外(wai)碳硫分析儀使(shi)得散熱(re)(re)(re)(re)(re)(re)損(sun)失增(zeng)加,從而降低(di)換熱(re)(re)(re)(re)(re)(re)器的(de)效率。當T2提高(gao)過大(da)時(shi),電熱(re)(re)(re)(re)(re)(re)元件(jian)表面的(de)溫(wen)度(du)亦會(hui)大(da)大(da)升(sheng)高(gao),致使(shi)一般電熱(re)(re)(re)(re)(re)(re)元件(jian)無法承受(shou),故T2的(de)增(zeng)加通常(chang)受(shou)到空氣(qi)(qi)加熱(re)(re)(re)(re)(re)(re)器中(zhong)(zhong)電熱(re)(re)(re)(re)(re)(re)元件(jian)材料耐熱(re)(re)(re)(re)(re)(re)性能的(de)限制(zhi)。