Crankcase Ventilation Line Diagnosis via Nitrogen Oxide Sensor
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Solution Overview
Problem
Internal combustion engines face issues with fuel dissolving in lubricants during cold starts, leading to undesirable lubrication changes, increased wear, and potential faults, with unburned fuel vapors potentially leaking into the environment through the crankcase ventilation system, necessitating effective monitoring for tightness and leaks in the crankcase ventilation line.
Innovation Solution
A method and device for diagnosing the crankcase ventilation line by diverting fresh air into the crankcase and using a nitrogen oxide sensor to detect concentrations, with predefined threshold values to evaluate tightness, leaks, and detachment, enabling fault detection and display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a crankcase ventilation line is used to vent fuel vapors and combustion by-products, then pressure build-up in the crankcase is prevented and emissions are controlled, but the system becomes susceptible to leaks and detachments that compromise tightness and environmental compliance
Solution Approach 1:
A nitrogen oxide sensor is introduced as an intermediary detection device in the intake tract to indirectly monitor the tightness of the crankcase ventilation line. The sensor detects nitrogen oxide concentrations in the intake air, which serve as indicators of potential leaks or detachments in the ventilation system, enabling monitoring without direct intervention in the crankcase ventilation line itself.
Solution Approach 2:
The system implements feedback by continuously monitoring nitrogen oxide concentrations in the intake air and using this information to infer the tightness status of the crankcase ventilation line. The control device receives sensor signals and processes them to determine whether the ventilation line is properly sealed, providing ongoing feedback about system integrity without requiring direct measurement of the ventilation line itself.
2Measurement precision
If nitrogen oxide concentration is monitored in the intake tract, then leaks and detachments in the crankcase ventilation line can be detected, but additional sensors and control systems are required
Solution Approach 1:
The nitrogen oxide sensor serves multiple functions: it monitors nitrogen oxide concentrations in the intake air for emission control purposes and simultaneously serves as an indicator for detecting tightness issues in the crankcase ventilation line. This multi-functionality allows the same sensor to provide dual benefits without requiring separate dedicated monitoring equipment.
Solution Approach 2:
The system uses existing intake air flow and nitrogen oxide detection capabilities to self-monitor the tightness of the crankcase ventilation line. The nitrogen oxide concentrations naturally present in the intake air serve as the monitoring medium, eliminating the need for separate test gases, pressure sensors, or additional active testing mechanisms.
3Object-affected harmful factors
If the crankcase ventilation system is monitored for tightness, then environmental compliance is ensured, but the monitoring process adds system complexity and potential failure points
Solution Approach 1:
The nitrogen oxide sensor acts as an intermediary that indirectly monitors ventilation line integrity without being part of the crankcase ventilation system itself. This separation means the monitoring function does not add components to the sealed crankcase ventilation path, avoiding potential leak sources while still providing effective monitoring through intake air analysis.
Solution Approach 2:
Instead of directly measuring parameters inside the crankcase ventilation system, the method uses nitrogen oxide concentrations in the intake air as a copy or proxy indicator of ventilation line tightness. This indirect measurement approach allows monitoring without physical intrusion into the sealed crankcase system.
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
This approach allows for simple and economic evaluation of the crankcase ventilation line's function, effectively detecting leaks and detachment, ensuring the system's tightness and reducing environmental emissions, thereby extending engine service life and compliance with regulatory standards.
Implementation Method 1
the nitrogen oxide concentration in the crankcase ventilation line (53) close to the point of introduction into the intake tract (1) upstream of the compressor (13) is detected by means of a nitrogen oxide sensor (56)
Data Source
AI summary
Various embodiments include a method for diagnosing a crankcase ventilation line of a crankcase ventilation device for an internal combustion engine having a crankcase, an intake tract, and a compressor arranged in the intake tract for compressing the intake air comprising: diverting fresh air from the intake tract via a fresh air supply line; either enabling or inhibiting a flow of fresh air into a free volume of the crankcase depending on a switch position of a shut-off valve in the fresh air supply line; detecting a nitrogen oxide concentration in the crankcase during the process of crankcase ventilation, close to the point of introduction into the intake tract upstream of the compressor using a nitrogen oxide sensor; and evaluating the tightness of the crankcase ventilation line based at least in part on the detected nitrogen oxide concentration.