An Experimental Study on GHG Emissions Reduction and Fuel Economy Improvement of Heavy-Duty Trucks by Using Aerodynamics Device Package

Internal combustion engines can be modified to operate regenerative braking cycles by using compressed air power. This paper presents a particular air hybridization design from among many possible configurations. The engine cycles are enabled by a highly flexible engine valvetrain, which actuates engine valves to generate desired torque with optimal efficiency. A lumped parameter model is developed first to investigate the cylinder-tank mass and energy interaction based on thermodynamic relationships and engine piston kinematics. Special consideration is given to the engine valve timing and air flow. A high fidelity, detailed model using the commercially available GT-Power software is developed for a commercial 10.8 liter heavy-duty diesel engine with a 280 liter air tank in order to capture the effects of engine friction, heat transfer, gas dynamics, etc. The model is used to develop optimal valve timing for engine control. The established engine maps are incorporated into the ADVISOR vehicle simulation package to evaluate the potential fuel economy improvement for a refuse truck under a variety of driving cycles. Depending on the particular driving cycle, the simulation has shown a potential 4% – 18% fuel economy improvement over the truck equipped with the conventional baseline diesel engine.

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Modeling of Compressed Air Hybrid Operation for a Heavy Duty Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.3078788 ◽

2009 ◽

Vol 131 (5) ◽

Cited By ~ 4

Author(s):

Xiaoyong Wang ◽

Tsu-Chin Tsao ◽

Chun Tai ◽

Hyungsuk Kang ◽

Paul N. Blumberg

Keyword(s):

Diesel Engine ◽

Fuel Economy ◽

Second Law Of Thermodynamics ◽

Lumped Parameter Model ◽

Compressed Air ◽

Heavy Duty ◽

Vehicle Simulation ◽

Heavy Duty Diesel Engine ◽

Fuel Economy Improvement ◽

Heavy Duty Diesel

This paper presents the analysis and modeling of a 10.8 l heavy-duty diesel engine modified for operating compressed air hybrid engine cycles. A lumped parameter model is developed to first investigate the engine cylinder-air tank mass and energy interaction. The efficiency of compressed air energy transfer is defined based on the second law of thermodynamics. A high fidelity model is developed using commercially available software (GT-POWER) to capture the effects of engine friction, heat transfer, gas dynamics, etc. Engine valve timing for optimal efficiency in air regeneration and the corresponding engine speed-torque maps are established using the detailed engine model. The compressed air hybrid engine maps are then incorporated into vehicle simulation (ADVISOR) to evaluate the potential fuel economy improvement for a refuse truck under a variety of driving cycles. Depending on the particular driving cycle, the simulation has shown a potential 4–18% fuel economy improvement over the truck equipped with the conventional baseline diesel engine.

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