Krenus, R., Passos, M., Ortega, T., Mowery, K. et al., "Ethanol Flex Fuel system with Delphi Heated injector application," SAE Technical Paper 2014-01-1369, 2014, doi:10.4271/2014-01-1369.
After the second worldwide oil crisis, Brazil put in place by 1975 a strategic plan to stimulate the usage of ethanol (from sugar cane), to be mixed to the gasoline or to be sold as 100% ethanol fuel (known as E100).To enable an engine to operate with both gasoline and ethanol (and their mixtures), by 2003 the “Flex Fuel” technology was implemented. By 2012 calendar year, from a total of about 3.8 million vehicles sold in the Brazilian market, 91% offered the “Flex Fuel” technology, and great majority used a gasoline sub-tank to assist on cold starts (typically below 15°C, where more than 85% of ethanol is present in fuel tank).The gasoline sub-tank system suffers from issues such as gasoline deterioration, crash-worthiness and user inconvenience such as bad drivability during engine warm up phase. This paper presents fuel injector technologies capable of rapidly electrically heating the ethanol fuel for the Brazilian transportation market. These heated fuel injectors can be used for cold starting ethanol fueled engines as presented in SAE paper 2009-01-0615  and to enable emissions reduction with a variety of automotive fuels as presented in SAE paper 2010-01-1265 .This paper will demonstrate the benefits and advantages obtained by introducing the individually-controlled heated injectors on Hyundai HB20 1.6L Flex Fuel vehicles, which besides assisting on cold starts, also helps to meet upcoming emissions legal requirements (Proconve L6). Additionally, it will enable meeting future stringent regulations that will require unburned ethanol (ETOH) emission to be considered by Brazilian legislation. Through significant fuel injection optimization on both cold start and emissions, these advantages will also allow lowering fuel consumption with E100 and potential catalyst converter savings.