EGEE 102
Energy Conservation and Environmental Protection

Heat Engines


Energy conversions occurring in an automobile are illustrated below:

Line drawing showing chemical energy flowing to thermal energy flowing to mechanical energy
Energy Conversions in an Automobile

Any device that converts thermal energy into mechanical energy—such as an automobile or a power plant—is called a heat engine. In these devices, high temperature heat (thermal energy) produced by burning a fuel is partly converted to mechanical energy to do work and the rest is rejected into the atmosphere, typically as a low temperature exhaust.

Heat Engine diagram showing that high temperature heat produced by burning fuel is converted into mechanical work and low temperature exhaust.
Heat Engine