FUEL PROPERTY DETERMINATION SYSTEM FOR INTERNAL COMBUSTION ENGINE

• US 20120239276A1
• Filed: 11/11/2010
• Published: 09/20/2012
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nishiumi, Ryoji
• Granted Patent: US 9,394,840 B2
• Time in Patent Office: Days
• US Class Current: 701/103
• CPC Class Codes: F02D 19/0605 to adjust the fuel pressure or temperature
• CPC Class Codes: F02D 19/061 by controlling fuel injectors
• CPC Class Codes: F02D 19/0628 Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 19/0636 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 19/0649 Liquid fuels having different boiling temperatures, volatilities, densities, viscosities, cetane or octane numbers
• CPC Class Codes: F02D 19/081 Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other
• CPC Class Codes: F02D 2200/0612 determined by estimation
• CPC Class Codes: F02D 35/026 using an estimation
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/146 the characteristics being an NOx content or concentration
• CPC Class Codes: F02D 41/1461 of the exhaust gases emitted by the engine
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A fuel injection pressure at a timing at which an NOx concentration (combustion temperature) indicates a maximum value under the condition that a fuel injection timing is fixed to a first injection timing is recorded as a first NOx peak injection pressure. Similarly, a second NOx peak injection pressure is recorded under the condition that the fuel injection timing is fixed to a second injection timing. A cetane number and distillation property of fuel are determined on the basis of these NOx peak injection pressures.

Claims

1. A fuel property determination system for a compression ignition internal combustion engine, comprising:

a first parameter changing unit that is configured to change a first operating parameter for varying a degree of mixing of fuel and air that are supplied into a combustion chamber of the internal combustion engine;

a second parameter changing unit that is configured to change a second operating parameter for varying a combustion temperature of a mixture of fuel and air;

a determination unit that is configured to determine a timing at which the combustion temperature indicates a maximum value when the first operating parameter is changed under the condition that the second operating parameter is fixed;

a first recording unit that is configured to record the first operating parameter at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the second operating parameter (InjT) is fixed to a predetermined first setting value as a first recorded value;

a second recording unit that is configured to record the first operating parameter at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the second operating parameter is fixed to a predetermined second setting value as a second recorded value; and

a fuel property determination unit that is configured to determine a cetane number and evaporation index of the fuel on the basis of the first recorded value and the second recorded value.

2. The fuel property determination system according to claim 1, wherein

the first operating parameter is any one of a fuel injection pressure and an engine coolant temperature.

3. The fuel property determination system according to claim 1, wherein

the second operating parameter is any one of a fuel injection timing, an intake air flow rate and a compression ratio.

4. The fuel property determination system according to claim 1, wherein

the determination unit includes an NOx concentration detecting unit that is configured to detect an NOx concentration in exhaust gas flowing through an exhaust passage, wherein the determination unit is configured to determine that a timing at which the NOx concentration in exhaust gas indicates a maximum value is the timing at which the combustion temperature indicates the maximum value when the first operating parameter is changed under the condition that the second operating parameter is fixed.

5. The fuel property determination system according to claim 1, wherein

the first operating parameter is a fuel injection pressure, the second operating parameter is a fuel injection timing, the determination unit includes an NOx concentration detecting unit that is configured to detect an NOx concentration in exhaust gas flowing through an exhaust passage, the determination unit is configured to determine a timing at which the NOx concentration in exhaust gas indicates a maximum value is a timing at which the combustion temperature indicates the maximum value when the fuel injection pressure is changed under the condition that the fuel injection timing is fixed, the first recording unit is configured to record the fuel injection pressure at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the fuel injection timing is fixed to the first setting value as the first recorded value, and the second recording unit is configured to record the fuel injection pressure at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the fuel injection timing is fixed to the second setting value as the second recorded value.

6. The fuel property determination system according to claim 1, wherein

the evaporation index is a distillation property.

7. The fuel property determination system according to claim 1, wherein

the evaporation index is the kinematic viscosity of the fuel.

8. A fuel property determination system for a spark ignition internal combustion engine, comprising:

a first parameter changing unit that is configured to change a first operating parameter for varying a degree of mixing of fuel and air that are supplied into a combustion chamber of the internal combustion engine;

a second parameter changing unit that is configured to change a second operating parameter for varying a combustion temperature of a mixture of fuel and air;

a determination unit that is configured to determine a timing at which the combustion temperature indicates a maximum value when the first operating parameter is changed under the condition that the second operating parameter is fixed;

a first recording unit that is configured to record the first operating parameter at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the second operating parameter is fixed to a predetermined first setting value as a first recorded value;

a second recording unit that is configured to record the first operating parameter at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the second operating parameter is fixed to a predetermined second setting value as a second recorded value; and

a fuel property determination unit that is configured to determine an octane number and evaporation index of the fuel on the basis of the first recorded value and the second recorded value.

9. The fuel property determination system according to claim 8, wherein

the first operating parameter is any one of a fuel injection pressure and an engine coolant temperature.

10. The fuel property determination system according to claim 8, wherein

the second operating parameter is any one of an ignition timing, an intake air flow rate and a compression ratio.

11. The fuel property determination system according to claim 8, wherein

the determination unit includes an NOx concentration detecting unit that is configured to detect an NOx concentration in exhaust gas flowing through an exhaust passage, wherein the determination unit is configured to determine that a timing at which the NOx concentration in exhaust gas indicates a maximum value is the timing at which the combustion temperature indicates the maximum value when the first operating parameter is changed under the condition that the second operating parameter is fixed.

12. The fuel property determination system according to claim 8, wherein

the first operating parameter is a fuel injection pressure, the second operating parameter is an ignition timing, the determination unit includes an NOx concentration detecting unit that is configured to detect an NOx concentration in exhaust gas flowing through an exhaust passage, the determination unit is configured to determine a timing at which the NOx concentration in exhaust gas indicates a maximum value is the timing at which the combustion temperature indicates the maximum value when the fuel injection pressure is changed under the condition that the ignition timing is fixed, the first recording unit is configured to record the fuel injection pressure at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the ignition timing is fixed to the first setting value as the first recorded value, and the second recording unit is configured to record the fuel injection pressure at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the ignition timing is fixed to the second setting value as the second recorded value.

13. The fuel property determination system according to claim 8, wherein

the evaporation index is a distillation property.

14. The fuel property determination system according to claim 8, wherein.

the evaporation index is the kinematic viscosity of the fuel.