# US 7,509,209 B2 · Methods and apparatus for operation of multiple fuel engines

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- Number: US 7,509,209 B2
- Document ID: US7509209B2
- Status: Granted
- Kind: B2
- Application number: 11/751,192
- Filed: 2007-05-21
- Published: 2007-12-27
- Granted: 2009-03-24
- Earliest claimed: 2002-09-24
- Assignees: Engine Control Technology, LLC
- Inventors: Frank J. Davis; Jozef Turlej
- Web page: https://patentgrep.com/patent/US7509209B2

## CPC

- F02D 41/0027: {the fuel being gaseous (non-electrical control F02D19/02)}
- F02D 19/027: {Determining the fuel pressure, temperature or volume flow, the fuel tank fill level or a valve position}
- F02D 19/061: {by controlling fuel injectors}
- F02D 19/0623: {Failure diagnosis or prevention; Safety measures; Testing}
- F02D 19/0631: {by estimation, i.e. without using direct measurements of a corresponding sensor}
- F02D 19/0647: {the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME]}
- F02D 19/066: {Retrofit of secondary fuel supply systems; Conversion of engines to operate on multiple fuels}
- F02D 19/0663: {Details on the fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers}
- F02D 19/105: {operating in a special mode, e.g. in a liquid fuel only mode for starting}
- F02D 41/0025: {Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures}
- F02D 2200/0406: Intake manifold pressure
- F02D 2200/0602: Fuel pressure
- F02D 2200/0606: Fuel temperature
- Y02T 10/30: Use of alternative fuels, e.g. biofuels
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

Methods and apparatus are disclosed for operation of a multiple fuel engine, which runs on a combination of two or more fuels. An electronic control unit (ECU) may be connected to the existing components of an engine system in order to control operation of the multiple fuel engine. The engine system may be mechanically governed or electronically controlled. The ECU inputs operating characteristics of the engine system, determines governing characteristics for multiple fuel operation based on the operating characteristics, and controls the amounts of fuel delivered to the engine based on the governing characteristics. In a preferred embodiment, a dual fuel engine operates using diesel as a first fuel and natural gas as a second fuel. The operating characteristics may include engine speed, throttle position, engine exhaust temperature, gas pressure of the second fuel, gas temperature of the second fuel, boost pressure of an intake manifold, or engine coolant temperature.

## Claims

### Claim 1

An electronic control unit for a multiple fuel engine utilizing a first fuel and a second fuel, the electronic control unit comprising:
an input that receives operating characteristics from an electronically controlled engine system, wherein at least one of the operating characteristics comprises gas pressure of the second fuel, gas temperature of the second fuel, boost pressure of an intake manifold, or engine coolant temperature; and
at least one output that controls amounts of the first fuel and the second fuel for delivery to the multiple fuel engine based on at least one of the operating characteristics, wherein an operating speed of the engine is maintained below a predetermined governed speed of the engine corresponding to a governed speed of the engine when the engine is only utilizing the first fuel.