環境因素對於車輛污染油耗測試影響之研究

本研究係以改變實驗室環境因素並以底盤動力計模擬車輛在路上行駛狀況，測試車輛是否因環境因素不同而造成排放污染物的變化。目前台灣車輛油耗污染測試依循「汽油汽車廢氣排放測試程序與方法」所有測試中環境溫度介於20℃∼30℃之間，在污染測試期間，測試環境或引擎進氣空氣的絕對溼度（H）必須達到5.5g≦H≦12.2g H2O/㎏乾燥空氣下執行FTP75測試。其中排氣管所排放之污染物分為CO、CO2、NOx、HC等，而測試時的環境溫度的確會造成部份的影響。污染物中的HC、CO及CO2隨著溫度升高有下降、NOx則著溫度升高有上升之趨勢，且較低溫度條件下所量測出來的油耗值會相對的較高。CO及HC生成因數為燃燒不完全所致，因為較低的環境溫度將造成引擎機油及冷卻水也處於較低溫度，又因為引擎於低溫下啟動比較容易產生CO及HC。NOx的生成因數為較高的燃燒溫度，所以NOx會隨著溫度升高而有增加的趨勢，但於相同溫度條件下較高的溼度產生較高的NOx。

關鍵字

引擎；車輛廢氣；底盤動力計

並列摘要

The object of this research is to investigate the relation between the test environment factors versus and the vehicle emission performance. The experiments are using the chassis dynamometer to simulate the vehicle driving condition. Presently, vehicle’s emission and fuel test is compliant with 「Gasoline Vehicle Emission Test Procedure and method」. In this standard, the environment temperature and the absolute humidity of test environment or engine air inlet need to between 20~30℃ and 5.5g~12.2g of the duration, respectively. The main contaminants of the exhaust are CO, CO2, NOx, and HC etc. The results shown that the THC, CO, and CO2 will decrease and NOx will increase with temperature rising. In lower temperature condition, the fuel economy will lower than normal. Producing of CO and HC are caused by un-completely combustion that will induce the engine oil and coolant in lower temperature due to lower ambient temperature. And if engine start in lower temperature state, it will be easily to produce CO and HC. Producing of NOx are caused by higher combustion temperature, so quantity of NOx will increase with temperature rising and in higher humidity.