FUNDAMENTALS OF THE DIESEL CYCLE

DOE-HDBK-1018/1-93 Diesel Engine Fundamentals FUNDAMENTALS OF THE DIESEL CYCLE FUNDAMENTALS OF THE DIESEL CYCLE Diesel engines operate under the principle of the internal combustion engine. There are two basic types of diesel engines, two-cycle and four-cycle. An understanding of how each cycle operates is required to understand how to correctly operate and maintain a diesel engine. EO 1.3 EXPLAIN how a diesel engine converts the chemical energy stored in the diesel fuel into mechanical energy. EO 1.4 EXPLAIN how the ignition process occurs in a diesel engine. EO 1.5 EXPLAIN the operation of a 4-cycle diesel engine, including when the following events occur during a cycle: a. Intake b. Exhaust c. Fuel injection d. Compression e. Power EO 1.6 EXPLAIN the operation of a 2-cycle diesel engine, including when the following events occur during a cycle: a. Intake b. Exhaust c. Fuel injection d. Compression e. Power The Basic Diesel Cycles A diesel engine is a type of heat engine that uses the internal combustion process to convert the energy stored in the chemical bonds of the fuel into useful mechanical energy. This occurs in two steps. First, the fuel reacts chemically (burns) and releases energy in the form of heat. Second the heat causes the gasses trapped in the cylinder to expand, and the expanding gases, being confined by the cylinder, must move the piston to expand. The reciprocating motion of the piston is then converted into rotational motion by the crankshaft. Rev. 0 ME-01 Page 21