Generators are widely used across the world as portable power units in case of power outages, used for emergency services and are also used in rural areas without access to electricity. The majority of commercially available generators use internal combustion engines designed as automobile engines with little or no optimization for use in generators. With operating conditions vastly different than that of automobile engines, they can be re-designed to operate much more efficiently as generator engines. The development objective here was to design a low cost, 1.6L, lean burn, internal combustion engine which minimizes heat losses, time losses and frictional losses to improve thermal efficiency. Various high swirl, high squish, easily CNC’d combustion chambers were created in the re-design process. A computer model was used to provide insight into the trade-off between time losses and heat losses. A maximum brake thermal efficiency of 37.2% was achieved.

In the realm of class 8 trucking, fuel economy and emissions compliance are becoming the driving force for development of new heavy-duty direct injected (HDDI) diesel engine technologies. Current production engines in this class convert around 40% of the fuels energy into usable work while the unused potential transfers to the environment as excess heat energy. Current OEMs are working toward decreasing this heat loss and improve engine efficiency and emissions. Quantifying the energy lost by component and system highlights the areas that demand the most attention. By studying test cell data of heat rejection on a production Cummins ISX engine and using the data to calibrate an engine model for the simulation software GT-Suite, heat rejection values and the components which transfer the energy are exposed. The simulation software provides energy transfer by both system and component type. The results reveal that 10% of engine total heat rejection (THR) is transferred through the cylinder wall to the engine coolant system. When the heat imparted on the cylinder wall is broken up by component, the piston rings contribute nearly as much heat into the liner as the combustion gas.