Internal

Combustion

Engines

Prof. (Dr.) M P Poonia

Director

NITTTR, Chandigarh

HEAT ENGINE

A heat engine – any device that is

capable of converting thermal

energy (heat) into mechanical

energy (work). We will consider an

important class of such devices

whose operation is cyclic

The Production of

Mechanical Power from the

Chemical Energy Contained

in the Fuel

PURPOSE

Energy Conversion Process

Chemical Energy

Heat Energy

Mechanical Energy

Electrical Energy

Combustion GeneratorMachine

Heat Engine

Conversion of

Heat into Work

HEAT TO WORK

Internal

Combustion

Engines

HEAT TO

WORK

Then Why is DIESEL called So……..

&What was it called before That….????

Do you Know…????RUDOLPH DIESEL invented Diesel

Engine, But He did not Discover the

Fuel DIESEL…..

HEAT TO WORKP

ress

ure

Volume

2

13

4

Work Done By Gas

Heat extractedWork Done

On Gas

Conversion of

Heat into Work

Examples of

Internal

Combustion

Engines

I C Engine

I C Engine

Basic Gas

Turbine Cycle

External

Combustion

Engines

Examples of

External

Combustion Engines

Working Fluid

(ICE)

One Working

Fluid (Air +Fuel

+ Residual Gas)

in Internal

Combustion

Engine

Working Fluid

(EC)

Normally Two

Working Fluid

(Air +Fuel +

Burnt Gases)

and Steam in

External

Combustion

Engine

Fuel Combustion

(IC)

Combustion of

the Fuel Takes

Place Inside

the Cylinder

Fuel Combustion

(EC)

Combustion of the Fuel Takes

Place Outside the Cylinder

Small and

Simple in Size

as Compared

to E.C. Engine

Because

Higher Power

to Weight

Ratio

Size (IC)

Heat Losses

(IC)

In this type of engine, no heat

transfer occurs, so the heat

losses are less

Heat Losses

(IC)

Advantages of

IC Engines Over

EC Engine

FAQ

1. How is a EC Engine Different from

an Internal Combustion (IC) Engine?

IC engines burn refined petroleum to

produce hot combustion gases. Those hot

gases move a piston within a cylinder. The

IC process is so fast that combustion

products are produced and then dissipate

almost immediately. Normally, the engine

speed is in the range of 2000 – 4000 rpm.

FAQ

In an EC engine, heat is produced by

burning fuel at ambient temperatures and

pressures. Ignition isn't "timed“; instead,

it's continuous, so any number of fuels

can be used to produce the required heat,

and that fuel is only burned in direct

proportion to the work required.

The most effective working fluid for the

expansion step in an EC engine transfers

power to the wheels quickly, safely and

efficiently.

FAQ

2. How Does External Combustion

Yield Higher Fuel Economy than

in IC Engine?

Fuel economy is the work performed per

unit of energy consumed. Energy for

every vehicle on the road comes from

combustion. Only 25-30% of the original

energy content of the gasoline or diesel

fuel is available to actually turn the

wheels..

FAQ

EC engines burn only enough fuel to

maintain an operating temperature.

When that temperature is reached, the

fuel flow is cut off. Mechanical losses are

similar. The net result is 40-50% of

available energy transferred to the wheel.

EC engines can produce far more torque

than IC engines of the same

displacement.

Thanks