Abstract
The paper studies the increase of performance of heavy duty diesel engine when the intake air is cooled by means of an air-air heat exchanger. For the turbocharged 798-05R engine manufactured at ROMAN truck factory there were presented dynamometric tests showing power, torque, specific fuel consumption and smoke level on the speed characteristic at total load. Other relevant indicators for engine development are the characteristics of iso-consumption, mechanical loss and mechanical efficiency. A stress is laid on the influence of air coolers. For two air coolers, a steel made and an aluminum made one, which were mounted on the same engine and tested on a dynamometric bench at Road Vehicle Institute (INAR) experimental data were compared. The solution of aluminum heat exchanger produced an increase of effective power of 4 HP and a reduction of specific fuel consumption of 4-8 g/HPh, over the whole range of speeds.
The results were commented based on other engines inter-cooling performance. The work shows a stage of the engine R&D based on previous simulations.
Keywords: diesel engine, inter-cooling, charge air cooler