Abstract
KEYWORDS – combined engine, diesel and brayton combined cycle, theory analysis, simulation, GT-Power
ABSTRACT – Due to thermal and mechanical limitations, conventional engines can’t meet the requirements of heavy duty vehicles for larger power density and lower fuel consumption of comprehensive working conditions at the same time. A new Diesel and Brayton combined engine was designed in order to research the feasibility to solve this problem. The configuration of the combined engine was presented. Theory model of the Diesel and Brayton combined engine was built adopting the equations of thermodynamics. And according to the set parameters of the theory cycle, the thermal efficiency and specific work were calculated. One diesel engine with turbocharger and intercooler and one gas turbine with similar rated power have been chosen to make the combined engine. Simulation model was built in GT-Power, and the performances under the rated condition were calculated, thus the power density can be evaluated. From the both two aspects, the expected benefits of larger power density and lower fuel consumption can be validated. Driving cycle based configuration and control strategy were proposed and tested. Results show that cycle efficiency of the combined engine can be 58% higher than that of gas turbine engine, while the power density of the combined engine can be 47% higher than that of diesel engine. The new designed engine can acquire high thermal efficiency and high power density, but deserves further researches before it can be widely used.