機車二次空氣對廢氣排放及觸媒轉換器之影響研究

A Study on the effect of secondary air in motorcycle to the exhaust pollution and catalytic converter

姚御凌(Yi-Ling Yao)

指導教授 ： 鄒忠全

崑山科技大學/工程學院/機械工程研究所/碩士(2009年)

https://doi.org/10.6828/KSU.2009.00023

摘要

本文主要目的在針對機車引擎冷車起動過程，探討二次空氣對觸媒轉換器及污染改善的影響。探討引擎溫車暫態和熱車穩態過程，與怠速及高轉速運轉狀況下之污染排放和觸媒轉換器溫度變化。在冷起動暫態下，引擎及觸媒轉換器均未達工作溫度，此時的汙染是非常嚴重的，故實驗利用高壓引進各種二次空氣流量，使污染排放廢氣能夠繼續燃燒，除了可以降低污染排放CO及HC外，還可以提高污染排放的溫度，使其能快速加熱觸媒轉換器和含氧感知器，提早達到工作溫度，提高觸媒轉換器轉換效率與減少污染排放。
本實驗使用主動式二次空氣，以光陽KYMCO奔騰G5 Fi 噴射引擎為測試車體，以電子方式來控制二次空氣流量，分別以10、20、30、40、50 L/min，導入汽缸頭旁的排氣歧管，藉此讓燃燒不完全的廢氣再繼續燃燒。如此可將燃燒不完全的HC和CO繼續燃燒，而且可同時加熱排氣管裡的氧化觸媒和含氧感知器，減少HC和CO的汙染排放。
經由一系列的實驗測試獲得結果為，主動式二次空氣比被動式二次空氣更能夠減低CO及HC的排放，但需要有大量的二次空氣對機車引擎污染排放CO及HC才有良好的淨化效果。在熱車實驗了解到，二次空氣流量在20 L/min以上，能夠有效同時改善CO、HC的排放量；在冷車實驗了解到，主動式二次空氣流量越大越能夠改善HC的排放量，而CO的排放量，只有在30 L/min以上，才有明顯的改善

關鍵字

CO ； HC ； 污染排放 ； 機車引擎 ； 二次空氣 ； 觸媒轉換器 ； 含氧感知器

並列摘要

This paper is mainly to discuss the effect of secondary air in motorcycles to the exhaust pollution and catalytic converter during the engine warm-up period. We measured the exhaust emissions and catalytic converter’s temperature during engine warm-up and the idle/high engine speed. Under the warm-up transient condition, the engine and catalytic converter are both not reach the working temperature. The pollution during this period is heavy. So in this experiment, we controlled different flows of high-pressure’s secondary air into the exhaust pipe to make exhaust emission to burn continuously. This operation will lower the amount of CO and HC in exhaust, it also can make exhaust temperature higher to heat the catalytic converter and oxygen sensor rapidly.The converting efficiency of the catalytic converter was improved and the exhaust pollution was reduced.
In this experiment we used active secondary air and the test engine is G5 Fi engine of KYMCO company. The secondary air flow was controlled electronically. The high-pressure secondary air into exhaust manifold near the cylinder head was controlled with the amount of 10、20、30、40、50 L/min respectively. By this method, the exhaust continue to burn the HC and CO in exhaust pipe. Then the emission to the environment was reduced.
Through a series of experiments, we found that the operation of the active secondary air is better than the passive one to lower the CO and HC amount in exhaust. But it needs large amount of active secondary air to reduce the CO and HC in exhaust. In the experiment under the stable operation of engine, we found that if the secondary air amount is over 20 L/min, it can reduce the CO and HC amount in exhaust at the same time. If under the warm-up operation of engine, we found that the larger amount the secondary air is, the lower amount the HC in exhaust. But the amount of CO only reduce obviously when the secondary air is over 30 L/min

並列關鍵字

CO ； HC ； pollution emissions ； locomotive engine ； secondary air ； catalytic converter ； oxygen sensor

參考文獻

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