汽車(che)(che)要(yao)跑(pao)(pao)得快(kuai)，就必須要(yao)有強勁(jing)的(de)(de)(de)動力(li)(li)。目前(qian)汽車(che)(che)的(de)(de)(de)動力(li)(li)系(xi)(xi)統(tong)(tong)可粗分為(wei)自然進(jin)氣(qi)系(xi)(xi)統(tong)(tong)及增(zeng)(zeng)壓(ya)進(jin)氣(qi)系(xi)(xi)統(tong)(tong)兩大類。在歐洲跑(pao)(pao)車(che)(che)中，除了(le)寶(bao)馬汽車(che)(che)公(gong)司依然堅持使用(yong)(yong)自然進(jin)氣(qi)發動機外，其他各汽車(che)(che)公(gong)司為(wei)了(le)提升車(che)(che)輛的(de)(de)(de)動力(li)(li)性能，紛紛采用(yong)(yong)增(zeng)(zeng)壓(ya)系(xi)(xi)統(tong)(tong)，例如：奔馳跑(pao)(pao)車(che)(che)使用(yong)(yong)機械增(zeng)(zeng)壓(ya)系(xi)(xi)統(tong)(tong)，紳寶(bao)汽車(che)(che)則為(wei)渦輪(lun)增(zeng)(zeng)壓(ya)的(de)(de)(de)開山鼻(bi)祖。近(jin)年(nian)日系(xi)(xi)汽車(che)(che)也開始大量采用(yong)(yong)渦輪(lun)增(zeng)(zeng)壓(ya)技術。自然進(jin)氣(qi)系(xi)(xi)統(tong)(tong)沒(mei)有安裝任何形式(shi)的(de)(de)(de)增(zeng)(zeng)壓(ya)器，只(zhi)是(shi)利用(yong)(yong)活(huo)塞下行所產生的(de)(de)(de)負(fu)壓(ya)來(lai)吸進(jin)混合氣(qi)。雖(sui)然自然進(jin)氣(qi)系(xi)(xi)統(tong)(tong)通(tong)過(guo)可變氣(qi)門正時系(xi)(xi)統(tong)(tong)能夠得到較大的(de)(de)(de)馬力(li)(li)輸(shu)出，但動力(li)(li)的(de)(de)(de)提升很有限。為(wei)了(le)有效(xiao)增(zeng)(zeng)加(jia)發動機的(de)(de)(de)輸(shu)出功率(lv)，采用(yong)(yong)增(zeng)(zeng)壓(ya)系(xi)(xi)統(tong)(tong)可說是(shi)最(zui)有效(xiao)的(de)(de)(de)方式(shi)。

最常(chang)見的發(fa)動機增壓系(xi)統有(you)機械增壓與廢氣渦(wo)輪增壓兩種。

機械增(zeng)壓

發動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)以機(ji)(ji)(ji)械(xie)(xie)(xie)方式(shi)(shi)驅動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)器進(jin)行增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)，稱(cheng)為機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)。當發動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)采用(yong)機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)時，通(tong)常(chang)由發動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)曲軸通(tong)過齒輪驅動(dong)(dong)(dong)(dong)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)器。增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)器一般采用(yong)離心式(shi)(shi)或羅(luo)茨(ci)壓(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)，個(ge)別的(de)(de)采用(yong)螺桿(gan)式(shi)(shi)壓(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)。近年(nian)來，在國外也開始采用(yong)新型的(de)(de)機(ji)(ji)(ji)械(xie)(xie)(xie)渦(wo)旋式(shi)(shi)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)器。因(yin)為驅動(dong)(dong)(dong)(dong)壓(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)消(xiao)(xiao)耗了發動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)一定(ding)(ding)的(de)(de)輸(shu)出(chu)功率(lv)(lv)，所(suo)以機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)發動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)的(de)(de)熱效率(lv)(lv)不(bu)一定(ding)(ding)得到改善，有(you)時反而比非增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)內燃(ran)(ran)機(ji)(ji)(ji)還低些。選擇(ze)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)力(li)時，首(shou)先要保(bao)證能達到所(suo)要求(qiu)(qiu)的(de)(de)平均有(you)效壓(ya)(ya)(ya)(ya)力(li)，其次要獲(huo)得盡可能低的(de)(de)燃(ran)(ran)油消(xiao)(xiao)耗率(lv)(lv)。擔這兩個(ge)要求(qiu)(qiu)對(dui)于機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)來說常(chang)常(chang)是(shi)相互(hu)矛盾(dun)的(de)(de)。如果追求(qiu)(qiu)平均有(you)效壓(ya)(ya)(ya)(ya)力(li)，則必然(ran)導致機(ji)(ji)(ji)械(xie)(xie)(xie)效率(lv)(lv)降(jiang)低，燃(ran)(ran)油消(xiao)(xiao)耗率(lv)(lv)升(sheng)高。因(yin)此(ci)，增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)力(li)值的(de)(de)選取應在功率(lv)(lv)和燃(ran)(ran)油消(xiao)(xiao)耗率(lv)(lv)兩者(zhe)之間尋求(qiu)(qiu)最佳的(de)(de)妥協方案(an)。機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)系統目(mu)前在歐洲車上(shang)用(yong)得較普遍。由于機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)的(de)(de)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)機(ji)(ji)(ji)是(shi)在曲軸的(de)(de)帶動(dong)(dong)(dong)(dong)下持續(xu)地運轉，因(yin)此(ci)不(bu)動(dong)(dong)(dong)(dong)產(chan)生(sheng)像渦(wo)輪增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)的(de)(de)渦(wo)輪遲滯現象。機(ji)(ji)(ji)械(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)雖然(ran)只能提升(sheng)約10%20%的(de)(de)動(dong)(dong)(dong)(dong)力(li)輸(shu)出(chu)，但平順(shun)連續(xu)性是(shi)渦(wo)輪增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)發動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)所(suo)不(bu)及的(de)(de)。

廢氣渦輪增(zeng)壓

利用發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)廢氣(qi)(qi)能(neng)量驅動(dong)渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)器(qi)，稱為(wei)廢氣(qi)(qi)渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)（簡稱渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)），如圖所(suo)示(shi)是(shi)(shi)(shi)廢氣(qi)(qi)渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)系(xi)統。廢氣(qi)(qi)渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)的(de)(de)(de)特點是(shi)(shi)(shi)在渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)器(qi)和發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)之(zhi)(zhi)間沒(mei)有(you)機(ji)(ji)(ji)(ji)(ji)械連接。它們之(zhi)(zhi)間靠氣(qi)(qi)路相通。因為(wei)壓(ya)(ya)氣(qi)(qi)機(ji)(ji)(ji)(ji)(ji)消耗(hao)的(de)(de)(de)功(gong)是(shi)(shi)(shi)渦(wo)(wo)輪(lun)(lun)從廢氣(qi)(qi)中(zhong)回(hui)收的(de)(de)(de)一部(bu)分(fen)能(neng)量，所(suo)以(yi)渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)不(bu)僅可以(yi)增(zeng)(zeng)(zeng)加(jia)發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)功(gong)率(lv)，而(er)且可以(yi)提(ti)高其(qi)熱(re)效率(lv)，降低燃油消耗(hao)率(lv)。如果在轎車尾部(bu)看到Turbo或者T的(de)(de)(de)標識，即表(biao)明該車采用的(de)(de)(de)發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)是(shi)(shi)(shi)渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)的(de)(de)(de)。渦(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)(ya)器(qi)實(shi)際(ji)上是(shi)(shi)(shi)臺空(kong)(kong)氣(qi)(qi)壓(ya)(ya)縮機(ji)(ji)(ji)(ji)(ji)，它是(shi)(shi)(shi)利用發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)排(pai)出(chu)的(de)(de)(de)廢氣(qi)(qi)慣性推動(dong)渦(wo)(wo)輪(lun)(lun)，渦(wo)(wo)輪(lun)(lun)又帶動(dong)同軸的(de)(de)(de)葉(xie)輪(lun)(lun)壓(ya)(ya)縮由空(kong)(kong)氣(qi)(qi)濾清器(qi)管道送(song)來(lai)的(de)(de)(de)空(kong)(kong)氣(qi)(qi)，使(shi)空(kong)(kong)氣(qi)(qi)增(zeng)(zeng)(zeng)壓(ya)(ya)后(hou)進入(ru)氣(qi)(qi)缸。當發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)轉(zhuan)速提(ti)高，廢氣(qi)(qi)排(pai)出(chu)速度與渦(wo)(wo)輪(lun)(lun)轉(zhuan)速也同步提(ti)高，葉(xie)輪(lun)(lun)就壓(ya)(ya)縮更多(duo)的(de)(de)(de)空(kong)(kong)氣(qi)(qi)進入(ru)氣(qi)(qi)缸，空(kong)(kong)氣(qi)(qi)的(de)(de)(de)壓(ya)(ya)力和密度增(zeng)(zeng)(zeng)大可以(yi)燃燒更多(duo)的(de)(de)(de)燃油，相應增(zeng)(zeng)(zeng)加(jia)油量和調整(zheng)一下發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)轉(zhuan)速，就可以(yi)增(zeng)(zeng)(zeng)加(jia)發(fa)動(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)輸出(chu)功(gong)率(lv)。