發動(dong)(dong)(dong)機(ji)采用(yong)機(ji)械(xie)(xie)(xie)方式驅動(dong)(dong)(dong)機(ji)械(xie)(xie)(xie)增壓(ya)(ya)(ya)(ya)(ya)器(qi)進行(xing)增壓(ya)(ya)(ya)(ya)(ya)，即機(ji)械(xie)(xie)(xie)增壓(ya)(ya)(ya)(ya)(ya)器(qi)。當發動(dong)(dong)(dong)機(ji)采用(yong)機(ji)械(xie)(xie)(xie)渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)時(shi)，發動(dong)(dong)(dong)機(ji)曲(qu)軸(zhou)通(tong)常(chang)(chang)通(tong)過(guo)齒輪驅動(dong)(dong)(dong)渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)器(qi)。渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)器(qi)一(yi)般采用(yong)離(li)心式或羅茨式壓(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)，有(you)時(shi)采用(yong)螺桿式壓(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)。近年來，國外采用(yong)了一(yi)種新型(xing)的(de)(de)(de)機(ji)械(xie)(xie)(xie)渦(wo)(wo)(wo)旋增壓(ya)(ya)(ya)(ya)(ya)器(qi)。由于(yu)驅動(dong)(dong)(dong)壓(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)消耗(hao)發動(dong)(dong)(dong)機(ji)一(yi)定的(de)(de)(de)輸出功率，渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)發動(dong)(dong)(dong)機(ji)的(de)(de)(de)熱效(xiao)率不(bu)一(yi)定提高，有(you)時(shi)甚至低于(yu)非渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)內燃(ran)機(ji)。選擇增壓(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)力(li)時(shi)，應(ying)(ying)首(shou)先保證平均(jun)有(you)效(xiao)壓(ya)(ya)(ya)(ya)(ya)力(li)，并盡可能(neng)(neng)降(jiang)低燃(ran)油消耗(hao)率。對于(yu)機(ji)械(xie)(xie)(xie)增壓(ya)(ya)(ya)(ya)(ya)，這兩(liang)個要求(qiu)常(chang)(chang)常(chang)(chang)是矛盾的(de)(de)(de)。如(ru)果追求(qiu)平均(jun)有(you)效(xiao)壓(ya)(ya)(ya)(ya)(ya)力(li)，機(ji)械(xie)(xie)(xie)效(xiao)率將(jiang)(jiang)不(bu)可避免地(di)降(jiang)低，燃(ran)油消耗(hao)率將(jiang)(jiang)增加。因(yin)此，在選擇增壓(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)力(li)值時(shi)，應(ying)(ying)找到(dao)功率和燃(ran)油消耗(hao)之(zhi)間的(de)(de)(de)最佳(jia)折衷點。機(ji)械(xie)(xie)(xie)增壓(ya)(ya)(ya)(ya)(ya)器(qi)系(xi)統目(mu)前(qian)廣泛應(ying)(ying)用(yong)于(yu)歐洲(zhou)車(che)輛。由于(yu)渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)器(qi)是在曲(qu)軸(zhou)驅動(dong)(dong)(dong)下(xia)連續工作的(de)(de)(de)，渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)器(qi)遲滯現象是不(bu)可改(gai)變(bian)的(de)(de)(de)。機(ji)械(xie)(xie)(xie)渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)只能(neng)(neng)使輸出功率提高10%和20%左(zuo)右，但渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)發動(dong)(dong)(dong)機(ji)的(de)(de)(de)平穩性(xing)和連續性(xing)不(bu)如(ru)渦(wo)(wo)(wo)輪增壓(ya)(ya)(ya)(ya)(ya)發動(dong)(dong)(dong)機(ji)。
精密鑄造廠廢氣渦輪增壓
利(li)用發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)廢氣(qi)(qi)(qi)(qi)能量驅(qu)動(dong)(dong)(dong)(dong)(dong)渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)器，稱(cheng)(cheng)為廢氣(qi)(qi)(qi)(qi)渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)(簡稱(cheng)(cheng)渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya))，如圖所示為廢氣(qi)(qi)(qi)(qi)渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)系統(tong)。廢氣(qi)(qi)(qi)(qi)渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)的(de)特點是渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)器與(yu)發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)之間沒有機(ji)(ji)(ji)械(xie)連接(jie)。它(ta)們是通過空(kong)(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)連接(jie)起來(lai)的(de)。由于壓(ya)(ya)(ya)(ya)(ya)縮機(ji)(ji)(ji)消耗了渦(wo)(wo)輪(lun)(lun)機(ji)(ji)(ji)從廢氣(qi)(qi)(qi)(qi)中回收的(de)部分能量，因此渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)不僅(jin)可(ke)以提高(gao)(gao)發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)的(de)功率(lv)，而(er)且可(ke)以提高(gao)(gao)發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)的(de)熱效率(lv)，降(jiang)低燃油消耗率(lv)。如果(guo)在(zai)(zai)汽車的(de)后部看到(dao)渦(wo)(wo)輪(lun)(lun)或(huo)T標志，它(ta)表明在(zai)(zai)汽車中使用的(de)發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)是渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)的(de)。渦(wo)(wo)輪(lun)(lun)增(zeng)壓(ya)(ya)(ya)(ya)(ya)器實(shi)際(ji)上是一種空(kong)(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)壓(ya)(ya)(ya)(ya)(ya)縮機(ji)(ji)(ji)，它(ta)利(li)用發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)的(de)廢氣(qi)(qi)(qi)(qi)慣性來(lai)驅(qu)動(dong)(dong)(dong)(dong)(dong)渦(wo)(wo)輪(lun)(lun)，渦(wo)(wo)輪(lun)(lun)驅(qu)動(dong)(dong)(dong)(dong)(dong)同軸葉輪(lun)(lun)壓(ya)(ya)(ya)(ya)(ya)縮空(kong)(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)過濾管發(fa)(fa)(fa)出的(de)空(kong)(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)，從而(er)使空(kong)(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)加(jia)(jia)壓(ya)(ya)(ya)(ya)(ya)進入氣(qi)(qi)(qi)(qi)缸。隨著發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)轉(zhuan)(zhuan)速的(de)提高(gao)(gao)，廢氣(qi)(qi)(qi)(qi)排放(fang)速度(du)與(yu)渦(wo)(wo)輪(lun)(lun)轉(zhuan)(zhuan)速同步增(zeng)大，葉輪(lun)(lun)將更多的(de)空(kong)(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)壓(ya)(ya)(ya)(ya)(ya)縮到(dao)缸內。增(zeng)加(jia)(jia)空(kong)(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)壓(ya)(ya)(ya)(ya)(ya)力(li)和密度(du)可(ke)以燃燒更多的(de)燃料(liao)。通過增(zeng)加(jia)(jia)燃油量和調(diao)整發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)轉(zhuan)(zhuan)速，可(ke)以提高(gao)(gao)發(fa)(fa)(fa)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)的(de)輸(shu)出功率(lv)。
