Internal Combustion Engine 01内燃机_精品.pdfVIP

Internal Combustion Engine Gasoline Engine 張崴縉 南臺科技大學 機械系 引擎運作的基本原理 Combustion 燃燒 Engine is a heat engine (熱機), which converts chemical energy (化學能) in a fuel into mechanical energy (機械能). Engine Classifications • Type of ignition • Fuel used – Spark Ignition (SI) 火 – Gasoline (Petrol 花點火 246 °C) – Compression Ignition – Diesel (210 °C) (CI)壓縮點火 – Gas, Natural Gas, • Engine Cycle Methane – LPG – Four-Stroke Cycle – Two-Stroke Cycle – Alcohol – Ethyl ( 乙基), Methyl(甲基 ) • Basic Design – Gasohol汽油酒精 – Reciprocating (往複式) – Rotary (轉子式 ) Spark-ignition engines • 燃料通常在在引擎進氣系統與空氣混合。 • 當燃氣壓縮時，釋出電荷開始燃燒過程。 • 由火星塞產生之核心所發展出之火焰，會傳遞越過汽缸到達燃燒室壁面。 • 由於熱傳遞或作用物質在壁面遭破壞成為主控程序，汽缸壁會將火焰 ”冷卻或“ 熄滅。 • 在火燄前大量的燃氣混合物之自發性點火，亦可能發生在火焰傳播至混合物( 尾氣 前。此自燃) 或自爆之燃燒現象，由於會產生高壓，是造成火花點火引擎 爆震 (knock)的原因，會導致引擎受損。 • The combustion process is a fast exothermic gas-phase reaction (where oxygen is usually one of the reactants). • A flame is a combustion reaction which can propagate subsonically through space. • The existence of flame motion implies that the reaction is confined to a zone which is small in thickness compared to the engine combustion chamber. • The reaction zone is usually called the flame front. This flame characteristic of spatial propagation is the result of the strong coupling between chemical reaction, the transport processes of mass diffusion and heat conduction, and fluid flow. • The generation of heat and active specie