A considerable part of the energy generated by an automotive internal combustion engine is wasted as
heat in the exhaust system. This wasted heat could be recovered and applied to power auxiliary systems
in a vehicle, contributing to its overall energy efficiency. In the present work, the experimental analysis of
an absorption refrigeration system was performed. The exhaust system of an automotive internal
combustion engine was connected to the generator element of an absorption refrigeration system. The
performance of the absorption refrigerator was evaluated as a function of the supplied heat. The use of a
control strategy for the engine exhaust gas mass flow rate was implemented to optimize the system.
Exhaust gas flow was controlled by step-motor actuated valves commanded by a microcontroller in
which a proportional-integral control scheme was implemented. Information such as engine torque,
speed, key temperatures in the absorption cycle, as well as internal temperatures of the refrigerator was
measured in a transient regime. The results indicated that the refrigeration system exhibited better
performance when the amount of input heat is controlled based on the temperature of the absorption
cycle generator. It was possible to conclude that, by dynamically controlling the amount of input heat, the
utilisation range of the absorption refrigeration system powered by exhaust gas heat could be expanded
in order to incorporate high engine speed operating conditions.