Fuel Leakage Detection in Engine Injection Systems
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Solution Overview
Problem
Current methods for detecting fuel leakage in internal-combustion engine injection systems cannot accurately determine if leakage occurs into the combustion chamber, leading to incomplete combustion and increased exhaust emissions.
Innovation Solution
A method involving the simultaneous capture of temporal fuel-pressure profiles in high-pressure and low-pressure branches using sensors, with checks for fuel loss and influx to determine if leakage occurs into the combustion chamber, allowing for precise detection and characterization of fuel leakage without additional sensory components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If pressure monitoring is performed only in the high-pressure branch, then fuel leakage detection is simplified, but the precision of leakage characterization is insufficient
Solution Approach 1:
The detection system is segmented into two independent pressure monitoring branches: high-pressure branch monitoring (for detecting leakage from common rail) and low-pressure branch monitoring (for detecting leakage into low-pressure system). This segmentation allows precise characterization of leakage paths while using existing separate pressure sensors already present in the fuel injection system.
2Measurement precision
If additional sensors are installed to improve leakage detection accuracy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The existing pressure sensors in the high-pressure and low-pressure branches, originally designed for fuel pressure monitoring during operation, are repurposed to serve dual functions: (1) normal fuel injection control, and (2) leakage detection after engine shutdown. This eliminates the need for additional dedicated leakage sensors while achieving precise leakage characterization.
3Object-generated harmful factors
If fuel leakage is detected early, then exhaust emissions are reduced, but detection reliability must be ensured to avoid false alarms
Solution Approach 1:
The system performs preliminary detection of fuel leakage immediately after engine shutdown by monitoring pressure changes in both high-pressure and low-pressure branches. By detecting leakage early before it causes significant emissions during restart or idle operation, the system can trigger warning signals or preventive measures while maintaining high reliability through comparison of pressure profiles against predetermined thresholds.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables easy and reliable detection of fuel leakage into the combustion chamber, preventing elevated exhaust emissions by quantifying the leakage and facilitating prompt repair, thus maintaining engine imperviousness and compliance with emissions regulations.
Implementation Method 1
in the high-pressure branch and in the low-pressure branch in each instance an associated temporal fuel-pressure profile is captured during a measuring period by way of sensors
Data Source
AI summary
A method and a device detect and characterize fuel leakage in an injection system of an internal combustion. The injection system has an injection device for injecting fuel into a combustion chamber of the internal combustion engine, a closable high-pressure branch for supplying the injection device with fuel placed under a first fuel pressure, and a closable low-pressure branch for feeding fuel placed under a second, lower fuel pressure from a fuel supply to the high-pressure branch. The high-pressure branch and the low-pressure branch are each closed, wherein in the high-branch branch and in the low-pressure branch an associated curve of fuel pressure over time is sensed at the same time during a measurement time period. On the basis of the sensed curve of fuel pressure of the high-pressure branch, it is checked whether fuel loss occurred in the closed-off high-pressure branch during the measurement time period. By way of the sensed curve of fuel pressure of the low-pressure branch, it is checked whether a flow of fuel into the closed-off low-pressure branch occurred during the measurement time period. If the existence of fuel loss was determined in the first checking step and additionally it was determined in the second checking step that no flow of fuel into the low-pressure branch occurred, a signal is output, which indicates fuel leakage from the high-pressure branch into the combustion chamber.