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U.S. Department of Energy
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Assessment of water addition to spark ignition engines

Technical Report ·
OSTI ID:6585977

This report presents an assessment of water addition to spark ignition engines based on data available in the open literature and on information obtained through communication with university, industrial, and government personnel. Water addition techniques addressed are (1) manifold injection or carburetion of water-gasoline emulsions, (2) separate induction of water and gasoline, (3) direct cylinder injection of water, (4) manifold water-vapor induction, and (5) water injection into the air intake. Test results show that water addition typically decreases vehicle fuel economy and NO/sub x/ emissions, increases HC emissions, and suppresses combustion knock. When accompanied by an engine compression ratio increase and/or advanced spark timing, limited data show that water addition can result in a moderate fuel economy increase at the expense of increased emissions. Unresolved problem areas include phase instability and cost of water-gasoline emulsions, engine corrosion, engine lubricant contamination and deposits, and the need for a freezing point depressant. Water-vapor induction devices (often misnamed as vapor injectors) available in the commercial automotive aftermarket have little or no effect on fuel economy. Because of its limited potential and added complexity and cost, research in water addition is not being pursued actively by automotive industry. However, Saab-Scania AB offers a water injection kit in Sweden, which is designed to provide a short period boost for Saab's two liter turbocharged automobile engine.

Research Organization:
Aerospace Corp., El Segundo, CA (USA)
DOE Contract Number:
AI01-82CS50286
OSTI ID:
6585977
Report Number(s):
DOE/CS/50286-3; ON: DE83006013
Country of Publication:
United States
Language:
English