Page 54 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Piston T. D. C. By injecting the fuel prior to arrival, the fuel mixes well with the air in the combustion chamber
and increases the pressure. (2 to 3). At the same time uniform combustion of the entire injected fuel begins with
the temperature exceeding the constant volume. The combustion process is completed in 3 to 4 hours and the
heat is increased under constant pressure. That is, a power stroke occurs. At this point (3-4) the T of the piston.
D. C. From B. D. C. Movement has started. So the volume is increasing. But the pressure is constant. Thus,
under constant pressure, combustion of fuel stops at point 4 and expansion of gas begins. (4 to 5) and 5 to 1
constant volume heat is released. Or the burnt gases are released directly from the cylinder. In a diesel engine,
the expansion stroke pressure is never less than atmospheric pressure.
Temperature – entropy: The temperature-entropy diagram (TS diagram) in which the thermodynamic state is
specified by a point on a graph with specific entropy (s) as the horizontal axis and absolute temperature (T) as
the vertical axis. TS diagrams are a useful and common tool, particularly because it helps to visualize the heat
transfer during a process. For reversible (ideal) processes, the area under the T-s curve of a process is the heat
transferred to the system during that process.

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CITS : Automotive - Mechanic Diesel - Lesson 08 - 10 CITS : Automotive - Mechanic Diesel - Lesson 08 - 10