汽(qi)(qi)車(che)要跑得(de)(de)快(kuai)，就必須要有(you)強勁的(de)動力(li)。目前汽(qi)(qi)車(che)的(de)動力(li)系(xi)(xi)(xi)統(tong)(tong)(tong)可粗(cu)分為(wei)自(zi)(zi)然(ran)(ran)進(jin)(jin)氣系(xi)(xi)(xi)統(tong)(tong)(tong)及增壓(ya)進(jin)(jin)氣系(xi)(xi)(xi)統(tong)(tong)(tong)兩大類。在歐洲(zhou)跑車(che)中，除了寶(bao)馬汽(qi)(qi)車(che)公司依(yi)然(ran)(ran)堅持使(shi)用自(zi)(zi)然(ran)(ran)進(jin)(jin)氣發動機外，其(qi)他(ta)各(ge)汽(qi)(qi)車(che)公司為(wei)了提升車(che)輛(liang)的(de)動力(li)性能，紛(fen)紛(fen)采(cai)用增壓(ya)系(xi)(xi)(xi)統(tong)(tong)(tong)，例如：奔馳跑車(che)使(shi)用機械增壓(ya)系(xi)(xi)(xi)統(tong)(tong)(tong)，紳寶(bao)汽(qi)(qi)車(che)則為(wei)渦(wo)輪增壓(ya)的(de)開山鼻祖。近年日系(xi)(xi)(xi)汽(qi)(qi)車(che)也開始大量(liang)采(cai)用渦(wo)輪增壓(ya)技術。自(zi)(zi)然(ran)(ran)進(jin)(jin)氣系(xi)(xi)(xi)統(tong)(tong)(tong)沒有(you)安裝任何形式的(de)增壓(ya)器，只是利(li)用活塞下行所(suo)產生的(de)負(fu)壓(ya)來吸進(jin)(jin)混(hun)合氣。雖然(ran)(ran)自(zi)(zi)然(ran)(ran)進(jin)(jin)氣系(xi)(xi)(xi)統(tong)(tong)(tong)通過可變氣門正時系(xi)(xi)(xi)統(tong)(tong)(tong)能夠得(de)(de)到較大的(de)馬力(li)輸(shu)出(chu)，但動力(li)的(de)提升很有(you)限。為(wei)了有(you)效增加(jia)發動機的(de)輸(shu)出(chu)功率，采(cai)用增壓(ya)系(xi)(xi)(xi)統(tong)(tong)(tong)可說是最有(you)效的(de)方式。

最常見的發動機增壓(ya)系統有機械增壓(ya)與廢氣(qi)渦輪增壓(ya)兩(liang)種。

機械增壓

發(fa)動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)以機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)方式(shi)(shi)驅(qu)(qu)動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)進行增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)，稱為(wei)機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)。當發(fa)動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)采(cai)用機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)時，通常由發(fa)動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)曲軸通過齒輪(lun)驅(qu)(qu)動(dong)(dong)(dong)(dong)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)。增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)一般采(cai)用離心式(shi)(shi)或羅茨壓(ya)(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)，個(ge)別的(de)(de)采(cai)用螺(luo)桿式(shi)(shi)壓(ya)(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)。近(jin)年(nian)來，在(zai)國外也開始采(cai)用新型的(de)(de)機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)渦旋式(shi)(shi)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)。因為(wei)驅(qu)(qu)動(dong)(dong)(dong)(dong)壓(ya)(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)消(xiao)(xiao)耗了發(fa)動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)一定(ding)的(de)(de)輸(shu)出功率，所(suo)以機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)發(fa)動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)的(de)(de)熱效(xiao)率不一定(ding)得到改善，有(you)(you)(you)時反而比非增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)內燃(ran)機(ji)(ji)(ji)還低(di)些。選擇增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)(ya)力時，首先要(yao)(yao)保證能(neng)達(da)到所(suo)要(yao)(yao)求(qiu)的(de)(de)平(ping)均有(you)(you)(you)效(xiao)壓(ya)(ya)(ya)(ya)(ya)(ya)力，其次要(yao)(yao)獲得盡可能(neng)低(di)的(de)(de)燃(ran)油消(xiao)(xiao)耗率。擔這兩(liang)(liang)個(ge)要(yao)(yao)求(qiu)對于(yu)機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)來說(shuo)常常是相(xiang)互(hu)矛盾(dun)的(de)(de)。如(ru)果追求(qiu)平(ping)均有(you)(you)(you)效(xiao)壓(ya)(ya)(ya)(ya)(ya)(ya)力，則必然(ran)導致機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)效(xiao)率降低(di)，燃(ran)油消(xiao)(xiao)耗率升高。因此，增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)(ya)力值(zhi)的(de)(de)選取應在(zai)功率和燃(ran)油消(xiao)(xiao)耗率兩(liang)(liang)者(zhe)之間尋求(qiu)最佳(jia)的(de)(de)妥協方案。機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)系統目前在(zai)歐洲車上用得較(jiao)普遍(bian)。由于(yu)機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)是在(zai)曲軸的(de)(de)帶動(dong)(dong)(dong)(dong)下(xia)持續地運轉，因此不動(dong)(dong)(dong)(dong)產(chan)生像渦輪(lun)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)渦輪(lun)遲滯現象。機(ji)(ji)(ji)械(xie)(xie)(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)雖然(ran)只能(neng)提(ti)升約10%20%的(de)(de)動(dong)(dong)(dong)(dong)力輸(shu)出，但(dan)平(ping)順連(lian)續性是渦輪(lun)增(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)(ya)發(fa)動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)所(suo)不及的(de)(de)。

廢氣渦輪增壓(ya)

利用發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)廢(fei)氣(qi)(qi)(qi)(qi)能(neng)量驅動(dong)(dong)(dong)渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)器，稱為(wei)廢(fei)氣(qi)(qi)(qi)(qi)渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)（簡稱渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)），如圖所示是(shi)(shi)(shi)(shi)廢(fei)氣(qi)(qi)(qi)(qi)渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)系統。廢(fei)氣(qi)(qi)(qi)(qi)渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)的(de)(de)(de)(de)特點(dian)是(shi)(shi)(shi)(shi)在渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)器和(he)發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)之(zhi)間(jian)沒有機(ji)(ji)(ji)(ji)械連接。它們之(zhi)間(jian)靠氣(qi)(qi)(qi)(qi)路相(xiang)通。因(yin)為(wei)壓(ya)氣(qi)(qi)(qi)(qi)機(ji)(ji)(ji)(ji)消耗的(de)(de)(de)(de)功(gong)是(shi)(shi)(shi)(shi)渦(wo)(wo)輪(lun)(lun)(lun)從廢(fei)氣(qi)(qi)(qi)(qi)中回收的(de)(de)(de)(de)一(yi)部(bu)(bu)分能(neng)量，所以渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)不僅可(ke)以增(zeng)(zeng)(zeng)(zeng)加發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)功(gong)率，而(er)且可(ke)以提(ti)(ti)高(gao)(gao)其熱效(xiao)率，降低(di)燃油(you)(you)消耗率。如果在轎車(che)尾部(bu)(bu)看到Turbo或者T的(de)(de)(de)(de)標識，即表明(ming)該車(che)采用的(de)(de)(de)(de)發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)是(shi)(shi)(shi)(shi)渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)的(de)(de)(de)(de)。渦(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)器實(shi)際上是(shi)(shi)(shi)(shi)臺空(kong)氣(qi)(qi)(qi)(qi)壓(ya)縮機(ji)(ji)(ji)(ji)，它是(shi)(shi)(shi)(shi)利用發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)排出(chu)的(de)(de)(de)(de)廢(fei)氣(qi)(qi)(qi)(qi)慣(guan)性推動(dong)(dong)(dong)渦(wo)(wo)輪(lun)(lun)(lun)，渦(wo)(wo)輪(lun)(lun)(lun)又帶動(dong)(dong)(dong)同軸(zhou)的(de)(de)(de)(de)葉(xie)輪(lun)(lun)(lun)壓(ya)縮由空(kong)氣(qi)(qi)(qi)(qi)濾清器管道送來的(de)(de)(de)(de)空(kong)氣(qi)(qi)(qi)(qi)，使(shi)空(kong)氣(qi)(qi)(qi)(qi)增(zeng)(zeng)(zeng)(zeng)壓(ya)后(hou)進入氣(qi)(qi)(qi)(qi)缸。當發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)轉(zhuan)速(su)提(ti)(ti)高(gao)(gao)，廢(fei)氣(qi)(qi)(qi)(qi)排出(chu)速(su)度與(yu)渦(wo)(wo)輪(lun)(lun)(lun)轉(zhuan)速(su)也同步提(ti)(ti)高(gao)(gao)，葉(xie)輪(lun)(lun)(lun)就(jiu)壓(ya)縮更多(duo)的(de)(de)(de)(de)空(kong)氣(qi)(qi)(qi)(qi)進入氣(qi)(qi)(qi)(qi)缸，空(kong)氣(qi)(qi)(qi)(qi)的(de)(de)(de)(de)壓(ya)力和(he)密度增(zeng)(zeng)(zeng)(zeng)大可(ke)以燃燒更多(duo)的(de)(de)(de)(de)燃油(you)(you)，相(xiang)應增(zeng)(zeng)(zeng)(zeng)加油(you)(you)量和(he)調整一(yi)下發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)轉(zhuan)速(su)，就(jiu)可(ke)以增(zeng)(zeng)(zeng)(zeng)加發(fa)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)輸出(chu)功(gong)率。