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林小男 Mar 30, 2006



⁨5⁩ ⁨個評論⁩

? [已註銷] Mar 31, 2006
The EGR valve is the main emissions control component in the exhaust gas recirculation system. The valve is located on the intake manifold, and opens a small passageway between the exhaust and intake manifold to allow a metered amount of exhaust to flow back into the engine. This reduces combustion temperatures and helps control the formation of oxides of nitrogen. The EGR valve is opened by the application of vacuum to its control diaphragm. Some also require a certain amount of exhaust back pressure before they'll open. On newer vehicles, the valve is electronic and uses one or more solenoids or a small stepper motor. The valve should remain closed while the engine is cold and at idle. It should only open once the engine has warmed up and is running at part-throttle. If the valve sticks shut (or is disconnected), NOX emissions will soar and detonation will often result (See Detonation and Spark Knock). If it sticks in the open position or fails to close all the way, it acts like a vacuum leak resulting in a rough idle, hesitation and possible stalling.

EGR (轉自TOYOTA汽車教室)

EGR(Exhaust Gas Recirculation廢氣再回收)是從排氣歧管接出一個旁通管至進氣歧管內,而將部分引擎廢氣隨著新鮮空氣導入引擎中燃燒,導入廢棄的量是由ECU依據當時引擎轉速、負荷等訊息所計算出來,並由EGR閥所控制。

EGR 的功用最主要是用來降低引擎中NOx的排放量的,其中NOx的產生是因為引擎燃燒溫度過高所致。本來,要降低燃燒溫度來抑制NOx的生成最好的方法就是延後點火提前角,然而點火角延後會大幅降低引擎性能並且提高油耗量,所以目前最好的解決方是就是裝設 EGR。EGR雖然會小幅的犧牲一點引擎性能,但卻能降低引擎燃燒溫度,以控制NOx的生成。經實驗證明,正確的利用EGR能降低百分之50的NOx生成量。如此便能大大減低觸媒轉換器的負擔,降低觸媒對於NOx的配方量,而節省觸媒轉換器的製造成本。

我有再拍照了..又要請大家幫小弟看看囉.謝謝 😮😮