Wet biofuel compression ignition
AssigneeWisconsin Alumni Research Foundation
InventorsDavid Darin Wickman, Sage Lucas Kokjohn
Life of this patent
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Abstract
A compression ignition engine system allows use of hydrous fuels, in particular hydrous biofuels, with high water content (e.g., 20-85% water). The hydrous fuel is pressurized, and also preferably heated via the engine's exhaust gas, to increase its enthalpy, and is then directly injected into the engine cylinder(s) near top dead center. The system provides brake thermal efficiency increases of 20% or more versus a comparable system using conventional diesel fuel, while allowing the use of inexpensive undistilled or lightly distilled biofuels.
Claims20
A compression ignition engine method including the step of injecting a hydrous fuel into a cylinder of a compression ignition engine to effect ignition of the hydrous fuel within the cylinder, wherein:
- a. the cylinder solely contains:
- (1) air, and
- (2) a hydrous fuel containing at least 20% water by mass,
- during ignition,
- b. the hydrous fuel is:
- (1) pressurized to a pressure of at least 50 bar,
- (2) heated to a temperature of at least 550 K, and
- (3) in a liquid or supercritical phase,
- prior to injection into the cylinder of the compression ignition engine.
A compression ignition engine method including the steps of:
- a. pressurizing a hydrous fuel to a pressure of at least 50 bar,
- b. heating the hydrous fuel to a temperature of at least 550 K,
- c. injecting the pressurized and heated hydrous fuel into a cylinder of the compression ignition engine in a liquid or supercritical phase during one or more of:
- (1) a compression stroke of the compression ignition engine, and
- (2) an expansion stroke of the compression ignition engine,
- to effect ignition of the hydrous fuel within the cylinder.
A compression ignition engine system including:
- a. a compression ignition engine,
- b. a fuel tank configured to contain a hydrous fuel,
- c. a fuel pump configured to supply the hydrous fuel to the compression ignition engine,
- d. a recuperator:
- (1) situated between the fuel pump and the compression ignition engine,
- (2) configured to transfer heat from exhaust from the compression ignition engine to the hydrous fuel,
- e. an injector configured to inject the heated hydrous fuel into a cylinder of the compression ignition engine,
- wherein
- i. the fuel pump is configured to pressurize the hydrous fuel to a pressure of at least 50 bar for supply to the injector, and
- ii. the recuperator is configured to heat the hydrous fuel to a temperature of at least 550 K.
Dependencies are inferred from the claim text.