Browse Publications Technical Papers 2012-36-0249
2012-10-02

An Onboard Ethanol Concentration Sensor for the Brazilian Market 2012-36-0249

A flex fuel engine is capable of operating efficiently on any combination of gasoline and ethanol. However, an engine combustion strategy must adapt quickly to a change in ethanol concentration after a refueling event in order to achieve optimum engine combustion. Typical control systems rely on an exhaust gas oxygen sensor (lambda) to measure changes in oxygen concentration following combustion. This feedback control approach can take five to ten minutes to detect the fuel change and correct the combustion strategy. This relatively long lag time could result in suboptimal engine performance such as a loss of engine power, engine knocking, poor cold start performance, unburned hydrocarbons, and high pollutant emissions. To counter this shortcoming, an on-board flex fuel sensor (FFS) was developed to enable a feed-forward control strategy. The FFS may be installed inline between the fuel tank and fuel injector and measure the fuel prior to it reaching the injector. The FFS sensor estimates the concentration of ethanol in the fuel in real-time using a correlation based on permittivity, conductivity, and temperature of the fuel flowing through the sensor. The FFS is specifically designed for the Brazilian market and is calibrated to measure the anhydrous ethanol and hydrous ethanol contained in gasohol and alcohol respectively. The sensor can accurately estimate the total ethanol concentration (anhydrous plus hydrous) within +/− five volume percent for any combination of gasohol and alcohol. The sensor can operate with a fuel temperature range of −40°C to 95°C. In addition, the FFS provides diagnostic capability and is able to identify and report water contamination to the engine control module.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Performance of a Methanol Fueled Car

811383

View Details

TECHNICAL PAPER

Delphi's Heated Injector Technology: The Efficient Solution for Fast Ethanol Cold Starts and Reduced Emissions

2012-01-0418

View Details

JOURNAL ARTICLE

Gaseous and Particulate Emissions Using Isobutanol-Extended Fuel in Recreational Marine Two-Stroke and Four-Stroke Engines

2014-32-0087

View Details

X