|Abstract: ||摘要:由於人類過度使用石化燃料,造成全球空氣汙染日趨嚴重,已經對人們身心健康及生態環境,有莫大之威脅,有鑑於此,世界各國之環保組織已有所警覺,將空氣汙染排放標準日益升高,特別針對在人口密度高交通繁忙區之機動車輛。而由於柴油引擎具有高輸出功率及結構堅固等優點,使得柴油車每年成長速度持續增高,但也成為空氣的主要汙染源,柴油引擎排放之汙染物以黑煙、氮氧化物、粒狀汙染物為主,皆是因燃油燃燒所產生,為了有效控制柴油車之汙染,改善燃料之研究就變得迫切重要。現今使用替代性燃料被認為可行有效之方法。本計畫在評估各種可能之替代性燃料之安全性、價格、效率、毒性等因素後,認為二次丙基二醇為一頗具發展潛力之替代性燃料。 分別調配不同比例之二次丙基二醇/柴油比,加入四氣缸柴油引擎,測試乳化油對引擎廢氣排放及性能影響。實驗結果顯示,氮氧化物隨著引擎轉速提高而降低,當二次丙基二醇比例增加時,曲線有先升高後下降之趨勢。在一氧化碳方面,則隨著轉速及二次丙基二醇比例提高而增多。|
Abstract:The overuse of fossil fuels by human beings has resulted in the increasingly serious problem of global air pollution, which leads to a large threat to the ecological environment and the health of human beings. Aware of this, international organizations of environment protection have raised the standard of combustion emissions, especially for those from the motor vehicles in metropolitan area of high population. The advantages of higher power output and more sturdy in structure for diesel engines have lead to the annual growth speed of diesel-powered vehicles increasingly higher, which becomes a major source of air pollution. The exhaust emissions of diesel engines are mainly smoke, oxides of nitrogen, and particulate originated from combustion of fuel. It has been considered an effective and feasible way to improve combustion emissions by using alternative fuels. In order to control effectively the exhaust emissions of diesel-powered vehicles, the study of alternative fuels has become a much important issue. After evaluating the safety, price, efficiency, toxicity of numerous possible alternative fuels in this study, dipropylene glycol is considered as an alternative fuel bearing a high potential of development. Various proportions of dipropylene glycol, diesel oil and distillated water were stirred by a homogenizing machine to constitute emulsified fuel oils. A four-cylinder diesel engine was employed to investigate the influences of using the emulsified oil as alternative fuel on the engine performance and emission characteristics. The experimental results show that nitrogen oxides (NOx) reduced with the increase of the engine speed. Moreover, the curves of NOx appear to increase and then decrease with the proportion of dipropylene glycol in the emulsified oil. In addition, the carbon monoxide emission significantly increased with either the engine speed or proportion of dipropylene glycol.