The Effects of Maintaining Constant Engine Air Intake Temperature on Its performance and Emissions

A laboratory evaluation work was conducted by a team of researchers to determine the effects on the performance, fuel consumption and emissions of a spark ignition (SI) engine powered vehicle, when a constant air intake temperature was maintained (pre-cooled condition). The temperature was regulated in the range of 32-34°C at all conditions of the trial. The air entering the engine combustion chamber is from a device installed at the existing automotive refrigeration system. The test was performed on the roller chassis dynamometer (Rotronics-Autoscan with KRONOS software) using a car of 1.6 litres, four automatic transmissions. Two types of tests were performed which they are i) steady-state test at part load throttle and ii) torque and power curves tests at wide open throttle. The salient points of this test work are the increment of the torque and power curves (6.0-19.59%), the reduction of the fuel consumption (average of 16.19%) and positive improvement on the exhaust emission (reduction of NOX and CO at the range 100-400 ppm and 200-700 ppm respectively) when the air intake temperature was maintained at the entrance of the engine combustion chamber.