Improvement of measurement efficiency at the engine test bench

Abstract: The improvement of measurement efficiency in industry is getting more andmore important. Faster measurement procedures lead to more experiments inless time and so reduce the costs. This master thesis is focusing on theimprovement of the conditioning unit on one of the test bench equipped with asmall turbocharged diesel engine.In order to test engine according to manufacturer specifications, the air going inthe cylinder has to be at a certain temperature depending on the load and thespeed of the engine. The intercooler, (exchanger air/air), being not present on atest bench, the intake air down-stream the turbocharger is cooled down by anair-water heat exchanger. This water is either warmed up by a heater or cooleddown by a water-water heat exchanger. The temperature of the water in thecooling/heating system is controlled in order to get the desired intake airtemperature. The cooling power is controlled by opening and closing a valve in acooling circuit and the heating power is depending of the amount electricityconsumed by the heater. Both of the cooling and heating units are controlled byone PI governor in a global control strategy.The cold hydraulic circuit has to be modified in order get a more precise flow inthe water-water exchanger to be able to control the intake air temperature. Thecooling power is the crucial part having more than 20 kW of cooling powerregarding the 6 kW of heating power. Once this step achieved, experiments willbe done in order to modify and optimize the control strategy to get the bestperformances of the system.Once this has been optimized, this control strategy will be adapted to other testbenches with different engine size in order to get better and fastermeasurements.