Dual fuel engine control

• US 20050121005A1
• Filed: 03/07/2003
• Published: 06/09/2005
• Est. Priority Date: 03/08/2002
• Status: Active Grant

• Current Assignee: i-SENS, Inc.
• Original Assignee: i-SENS, Inc.
• Inventors: Edwards, John
• Granted Patent: US 7,093,588 B2
• Time in Patent Office: Days
• US Class Current: 123/525
• CPC Class Codes: F02B 2201/06 Dual fuel applications
• CPC Class Codes: F02D 19/0631 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 19/105 operating in a special mode, e.g. in a liquid fuel only mode for starting
• CPC Class Codes: F02D 41/0027 the fuel being gaseous non-electrical control F02D19/02
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A gas substitution system for a dual fuel diesel engine which monitors load and RPM and the operational state of the engine and vehicle including throttle displacement, cruise control, idle, wheel and engine braking, manual control. Data is collected to establish parameters such as fuel consumption and exhaust emissions for load/RPM pair values and using these to create a table of optimum gas substitution values at each load RPM pair within the range of operational states within which substitution is viable. The system is applicable to: constant engine speed stationary applications (gensets); variable engine speed applications, including mobile plant; automative applications with no existing engine management system; automative applications with a basic existing engine management system; automative applications with an advanced existing engine management system.

Claims

1. A method of controlling addition of gas into a dual fuel diesel engine in which

a) engines are monitored to develop a set of data of fuel requirements against load and RPM;

b) the control system monitors the load and RPM of the engine and comparing these to the stored data determines the appropriate gas addition.

2. A method as claimed in claim 1 in which the volume of gas is calculated to replace part of the energy supplied by the diesel fuel as a function of output load.

3. A method as claimed in claim 1 which is applied to a stationary engine and the governor output signal is used to derive instantaneous load and using that measurement to determine the gas substitution.

4. A method as claimed in claim 1 wherein the data set of fuel requirements establishes the optimum gas substitution for each set of load and RPM values.

5. A control system for the addition of gas to vehicle dual fuel diesel engine which includes

a) a sensor to sense RPM

b) a sensor to sense engine load

c) oil pressure and engine temperature sensors to provide alerts and optionally exhaust temperature alert sensor

d) sensors to sense the operational state of the vehicle and the engine including one or more of cruise control, manual control, braking, idling, cold start and accelerating sensors

e) optionally throttle position or road speed sensors.

9. A control system as claimed in claim 5 which only substitutes gas for diesel fuel when the vehicle is not braking, not idling and the throttle is not fully depressed.

6. ) A control system for the substitution of gas for diesel in a dual fuel diesel engine which includes

a) means to sense or derive RPM

b) means to sense or derive Load

c) storage means for a set of data of fuel requirements against load and RPM;

d) a control system which monitors the load and RPM of the engine and comparing these to the stored data determines the appropriate gas substitution.

7. A gas substitution control system as claimed in claim 6 for an engine having an advanced electronic engine management system wherein the means to sense or derive RPM and load are part of the advanced electronic engine management system.

8. A control system as claimed in claim 6 which also includes means to sense the operational state of the vehicle and the engine including one or more of cruise control, manual control, braking, idling, cold start and accelerating.

10. A system of analysing engine performance to assist in the improved control of the engine which includes

a) measuring devices for measuring parameters including engine load, RPM, fuel injected, air inlet temperature, exhaust temperature, oxygen or carbon dioxide levels in the exhaust gases, at discrete time intervals

b) electronic storage means for storing the data collected by the measuring devices at each of said discrete time intervals

c) means to analyse the stored data to establish a data table for each parameter against each measured engine load and RPM point.

11. A system as claimed in claim 10 in which imaging software is used to present the data sets for each parameter as a 3 dimensional surface plotted against load and RPM.

12. A system for managing the gas substitution for dual fuel engines which includes

a) a control system which continuously controls an amount of gas to be added and an amount of diesel fuel to be reduced

b) an information feed back system which records and/or displays measured and/or derived representations of current and historical engine operating parameters

c) an analysis system which identifies from the information feed back system for each engine family across total load and RPM ranges, the diesel only and dual fuel operating characteristics

d) a programming system which contains a library of default control system operating parameter programs created by the analysis system for each engine family.

13. A system as claimed in claim 12 wherein the information feed back system collects data including fuel consumption and exhaust emissions data which the analysis system uses to produce programs for the control system to optimize the addition of fuel to achieve optimum economic and/or environmental performance across the load/speed range.