Modelling and Experimental Validation of a VNT Turbocharger for Improving Performances of a Marine Diesel Generator Engine

This paper presents modelling and experimental validation for improving the performances of a marine diesel generator engine.Based on the diesel engine theory, the laws of conservation of energy, and the principle of movement of fl ow through turbocharger nozzle, a mathematical model of a real turbocharged engine was built, concentrating on the mathematic model of fl ow through nozzles.This model is simulated by Matlab/Simulink program, the results of simulation showed the relationships between the engine and the turbocharger, the turbine and the compressor, and between the nozzles and the turbocharger.The experiments were carried out to validate this model, the errors between the simulation and measure were acceptable.The measure and simulation results also determined that at the low load conditions (≤50% load) engine performances can be improved by adjusting nozzle opening degree (from fully opening to 90% and 80% opening).Sažetak Ovaj rad prikazuje modeliranje i eksperimentalnu validaciju za poboljšanje performansi brodskog motora s dizel generatorom.Na temelju teorije dizel motora, zakona očuvanja energije i načela kretanja protoka kroz mlaznicu turbopuhala izrađen je matematički model pravog motora s turbopunjenjem, s fokusom na matematičkom modelu protoka kroz mlaznice.Ovaj model je simuliran programom Matlab / Simulink, a rezultati simulacije pokazali su odnos motora i turbopuhala, turbine i kompresora, te mlaznica i turbopuhala.Eksperimenti su provedeni kako bi se provjerio ovaj model, a pogreške između simulacije i mjere bile su prihvatljive.Rezultati mjerenja i simulacije također su odredili da se pri uvjetima malog opterećenja (≤ 50 % opterećenja) performanse motora mogu poboljšati podešavanjem stupnja otvaranja mlaznica (od potpunog otvaranja do 90 % i 80 % otvaranja).