US-12624668-B2 - Engine system and method for determining fuel characteristics

US12624668B2US 12624668 B2US12624668 B2US 12624668B2US-12624668-B2

Abstract

A method for determining a fuel characteristic, the method including receiving a gaseous fuel within a gaseous fuel rail of a dual fuel engine configured to run on at least the gaseous fuel and a diesel fuel. The method may include receiving a pressure signal from a pressure sensor indicating a pressure of the gaseous fuel within the gaseous fuel rail, and identifying at least one of an amplitude and a phase of the pressure signal, The method may further include determining a characteristic of the fuel within the fuel rail based on the amplitude or the phase of the pressure signal, and, based on the determined characteristic of the fuel, modifying an operational parameter of the dual fuel engine.

Inventors

Michael Graziano
Jason J. Rasmussen

Assignees

CATERPILLAR INC.

Dates

Publication Date: 20260512
Application Date: 20240717

Claims (20)

1 . A method, comprising: receiving a gaseous fuel within a gaseous fuel rail of a dual fuel engine configured to run on the gaseous fuel and a diesel fuel; initiating a change in the pressure of the gaseous fuel by opening a gas admission valve (GAV) configured to supply fuel from the gaseous fuel rail to an engine cylinder; closing the GAV to seal the gaseous fuel rail; receiving a pressure signal from a pressure sensor indicating a fluctuating pressure of the gaseous fuel within the gaseous fuel rail; identifying a phase lag of the pressure signal; determining a characteristic of the gaseous fuel within the gaseous fuel rail based on the phase lag of the pressure signal; and based on the determined characteristic of the gaseous fuel, modifying an operational parameter of the dual fuel engine.
2 . The method of claim 1 , further comprising: initiating a change in the pressure of the gaseous fuel by opening a gas admission valve (GAV) configured to supply fuel from the gaseous fuel rail to an engine cylinder; closing the GAV to seal the gaseous fuel rail; and determining the characteristic of the gaseous fuel based on an amplitude value, in addition to the phase lag of the pressure signal, resulting from the opening of the GAV.
3 . The method of claim 1 , further comprising: applying a strategy that includes integrating the pressure signal for determining the characteristic of the gaseous fuel based on an amplitude of the pressure signal in addition to the phase lag of the pressure signal.
4 . The method of claim 1 , wherein modifying the operational parameter of the dual fuel engine includes adjusting a spark timing of the dual fuel engine.
5 . The method of claim 1 , further comprising, based on the determined characteristic of the gaseous fuel, displaying a warning on a display.
6 . The method of claim 1 , further comprising, based on the determined characteristics of the gaseous fuel, adjusting a quantity of the gaseous fuel.
7 . The method of claim 1 , further comprising determining the characteristic of the gaseous fuel within the gaseous fuel rail as part of a start-up test of the dual fuel engine.
8 . A method, comprising: initiating a change in a pressure of a gaseous fuel within a gaseous fuel rail by opening a gas admission valve (GAV) configured to supply the gaseous fuel from the gaseous fuel rail to an engine cylinder of an internal combustion engine; closing the GAV to seal the gaseous fuel rail; receiving a pressure signal representing the pressure of the gaseous fuel; identifying a phase lag or a time lag of the pressure signal after the GAV has closed; determining a specific gravity of the gaseous fuel within the gaseous fuel rail based on the phase lag or the time lag of the pressure signal; and based on the specific gravity of the gaseous fuel, performing one or more of: modifying an operational parameter of the internal combustion engine, displaying a warning on a display, or adjusting a quantity of the gaseous fuel.
9 . The method of claim 8 , wherein modifying the operational parameter of the internal combustion engine includes retarding a spark timing of the internal combustion engine when the specific gravity of the gaseous fuel is above a threshold value.
10 . The method of claim 8 , including adjusting the quantity of the gaseous fuel supplied to the internal combustion engine via the gaseous fuel rail when the specific gravity of the gaseous fuel is above a threshold value.
11 . The method of claim 8 , wherein modifying the operational parameter of the internal combustion engine further includes derating the internal combustion engine when the specific gravity of the gaseous fuel is above a threshold value.
12 . The method of claim 8 , further comprising displaying the specific gravity on the display.
13 . The method of claim 8 : further comprising comparing the specific gravity of the gaseous fuel within the gaseous fuel rail with an expected specific gravity of the gaseous fuel; and wherein the operational parameter of the internal combustion engine is modified based on the comparison of the specific gravity of the gaseous fuel with the expected specific gravity of the gaseous fuel.
14 . The method of claim 8 , wherein the specific gravity is determined while the internal combustion engine is operating and combusting the gaseous fuel.
15 . A system, comprising: an internal combustion engine assembly including an internal combustion engine configured to operate with at least a gaseous fuel, the internal combustion engine assembly including: a fuel system; and a gaseous fuel rail of the fuel system, the gaseous fuel rail configured to receive the gaseous fuel; at least one sensor for measuring a pressure within the gaseous fuel rail; and a controller in communication with the at least one sensor and configured to: initiate a change in the pressure of the gaseous fuel by causing a gas admission valve (GAV) configured to supply fuel from the gaseous fuel rail to an engine cylinder to open; cause the GAV to close to seal the gaseous fuel rail; receive a pressure signal from the at least one sensor indicating a fluctuating pressure of the gaseous fuel within the gaseous fuel rail; identify a phase lag of the pressure signal; determine a characteristic of the gaseous fuel within the gaseous fuel rail based on the phase lag of the pressure signal; and based on the determined characteristic of the gaseous fuel, modify an operational parameter of the internal combustion engine.
16 . The system of claim 15 , wherein the at least one sensor includes at least two sensors.
17 . The system of claim 15 , wherein the at least one sensor is connected at an end of the gaseous fuel rail.
18 . The system of claim 17 , further comprising a gas admission valve (GAV) coupled between the gaseous fuel rail and a plurality of combustion cylinders, wherein the at least one sensor being configured to detect fluctuations in pressure caused by actuation of the GAV.
19 . The system of claim 15 , wherein the controller is further configured to, based on the determined characteristic of the gaseous fuel, adjust a spark timing of combustion cylinders of the internal combustion engine.
20 . The system of claim 15 , wherein the controller determines the characteristic of the gaseous fuel while the internal combustion engine is at startup or while the internal combustion engine is operative.

Description

TECHNICAL FIELD The present disclosure relates determining a characteristic of fuel, and, more particularly, determining a characteristic of fuel for an internal combustion engine. BACKGROUND Internal combustion engines combust fuels to generate energy. While some engines operate in environments in which fuel characteristics are consistent, other engines are used in environments where fuel characteristics change over time. The properties of a given fuel impact engine performance, emissions, fuel consumption, and other aspects of the combustion engine's operation. As an example, specific gravity impacts engine performance as decreasing specific gravity tends to hasten the rate at which combustion occurs. Some engine systems are configured to adjust operation based on changes in the properties of fuel, including specific gravity, by allowing a user to manually enter values into, for example, a computing device associated with the engine. The computing device adjusts operational parameters of the engine in response to values received from the user, compensating for the change to the rate of combustion. Physical properties of fuel, including specific gravity, may change, for example, when fuel obtained directly from a well or worksite. In at least some circumstances, changes to specific gravity or other fuel characteristics occur quickly. While existing systems that adjust based on specific gravity are useful, there are at least some occasions in which it is difficult to obtain an accurate specific gravity measurement to allow the internal combustion engine to perform adjustments and compensate for changes in the fuel. A specific gravity detection device for an internal combustion engine is described in JP 2019019748 A (“the '748 publication”) to Takano. A fuel pressure detection unit described in the '748 publication detects fuel pressure and a specific gravity of fuel is based on a calculated fuel density. While the detection unit described in the '748 publication may be useful for estimating the specific gravity in some circumstances, it is unable to provide a specific gravity of fuel based on characteristics of a pressure signal such as amplitude, phase, and others. Embodiments of the present disclosure may solve one or more of the problems set forth above and/or other problems in the art. The scope of the current disclosure, however, is defined by the attached claims, and not by the ability to solve any specific problem. SUMMARY In one aspect of the present disclosure, a method for determining a fuel characteristic may include receiving a gaseous fuel within a gaseous fuel rail of a dual fuel engine configured to run on at least the gaseous fuel and a diesel fuel. The method may include receiving a pressure signal from a pressure sensor indicating a pressure of the gaseous fuel within the gaseous fuel rail, and identifying at least one of an amplitude and a phase of the pressure signal. The method may also include determining a characteristic of the fuel within the fuel rail based on the amplitude or the phase of the pressure signal, and, based on the determined characteristic of the fuel, modifying an operational parameter of the dual fuel engine. In another aspect of the present disclosure, a method may include receiving a gaseous fuel within a gaseous fuel rail for supplying the gaseous fuel to an internal combustion engine configured to run on at least gaseous fuel, and measuring a pressure signal of the gaseous fuel within the fuel rail. The method may include identifying at least one of an amplitude or a phase of the pressure signal, and determining a specific gravity of the fuel within the fuel rail based on the amplitude or phase of the pressure signal. The method may also include, based on the specific gravity of the fuel, performing one or more of: modifying an operational parameter of the combustion engine, displaying a warning on a display, or adjusting a quantity of the gaseous fuel. In still another aspect of the present disclosure, a gaseous fuel specific gravity estimation system may include an internal combustion engine assembly configured to operate with at least gaseous fuel. The engine assembly may include a fuel system, and a fuel rail of the fuel system, the fuel rail configured to receive gaseous fuel. The system may include a sensor for measuring a pressure within the fuel rail, and a controller in communication with the sensor and configured to receive a pressure signal from a pressure sensor indicating a pressure of the gaseous fuel within the gaseous fuel rail, identify at least one of an amplitude and a phase of the pressure signal, determine a characteristic of the fuel within the fuel rail based on the amplitude or the phase of the pressure signal, and, based on the determined characteristic of the fuel, modify an operational parameter of the internal combustion engine. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in, and constitute a par