Method for ascertaining a quality characteristics of a diesel fuel

• US 20080308067A1
• Filed: 06/06/2008
• Published: 12/18/2008
• Est. Priority Date: 06/14/2007
• Status: Abandoned Application

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schumacher, Herbert, Schuckert, Marko, Dzeko, Sanl, Jin, Liwel
• Application Number:
  US12/157,208
• Publication Number:
  US 20080308067A1
• Time in Patent Office: Days
• US Class Current: 123/435
• 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 2200/0612 determined by estimation
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 35/028 by determining the combustion timing or phasing
• 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: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A method for ascertaining a quality characteristic of a Diesel fuel for a Diesel internal combustion engine, having a device for determining the cylinder pressure curve of at least one cylinder, a process variable of the combustion being ascertained from the cylinder pressure curve, which characterizes the fuel quality.

Claims

1. A method for ascertaining a quality characteristic of a Diesel fuel for a Diesel internal combustion engine, the method comprising:

determining a cylinder pressure curve of at least one cylinder of the engine; and

ascertaining a process variable of a combustion as a function of the cylinder pressure curve, which characterizes the fuel quality.

2. The method according to claim 1, wherein the process variable is a distance between a point of injection and a combustion center point.

3. The method according to claim 1, wherein the process variable is a distance between a point of injection and a time of a maximum of a heat-release development.

4. The method according to claim 1, further comprising correcting the process variable by a correction value that is a function of environmental conditions of the internal combustion engine.

5. The method according to claim 4, further comprising ascertaining the correction value as a function of at least one of an environmental temperature, an environmental pressure, an engine pressure and an additional torque requirement by auxiliary assemblies of the internal combustion engine.

6. The method according to claim 1, wherein the ascertainment of the process variable takes place during a test operation under specified boundary conditions.

7. The method according to claim 6, wherein the specified boundary conditions include at least one of a crankshaft speed, a load, a supercharging pressure, an exhaust gas recirculation rate, an injection pressure and a beginning of injection.

8. The method according to claim 6, further comprising depositing single injections during the test operation.

9. A device for ascertaining a quality characteristic of a Diesel fuel for a Diesel internal combustion engine, comprising:

means for determining a cylinder pressure curve of at least one cylinder of the engine; and

means for ascertaining a process variable of a combustion as a function of the cylinder pressure curve, which characterizes the fuel quality.

10. The device according to claim 9, wherein the device is a control unit.

11. A computer-readable medium containing a computer program which when executed by a processor performs the following method for ascertaining a quality characteristic of a Diesel fuel for a Diesel internal combustion engine:

determining a cylinder pressure curve of at least one cylinder of the engine; and

ascertaining a process variable of a combustion as a function of the cylinder pressure curve, which characterizes the fuel quality.