Crankcase Ventilation Gas Detection and Routing
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Solution Overview
Problem
Existing crankcase ventilation systems in internal combustion engines face challenges in managing fuel leakage into the crankcase during engine standstill, which can lead to startability issues and safety hazards due to the risk of fire or explosion.
Innovation Solution
A system that includes a closed circuit conduit for guiding crankcase gas to the air inlet guide and an open circuit conduit for venting crankcase gas to the atmosphere, equipped with gas detection means positioned in the air inlet guide or open circuit conduit to detect leaks and a valve arrangement to selectively route crankcase gas between the closed and open circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a closed crankcase ventilation system is used to manage fuel leakage, then fuel evaporation and combustion efficiency improve, but the risk of knocking combustion, backfiring and engine runaway increases with volatile fuels like DME
Solution Approach 1:
The crankcase ventilation system is segmented into multiple pathways: a first pathway directs crankcase gas to the combustion chamber for controlled combustion, while a second pathway provides a bypass route to the atmosphere. This segmentation allows the system to manage volatile fuel vapors by providing alternative routes, preventing over-pressurization and reducing the risk of knocking combustion and backfiring while maintaining effective fuel leakage management.
2Object-affected harmful factors
If an open crankcase ventilation system is used to vent vaporized fuel to the atmosphere, then the risk of knocking combustion and backfiring is reduced, but safety hazards and environmental burden increase
Solution Approach 1:
The system implements local quality by providing different treatment for crankcase gas under different operating conditions. During normal operation, the first pathway directs gas to the combustion chamber for beneficial combustion. During standstill or high-vapor conditions, the second pathway activates to safely vent excess vapors to the atmosphere, preventing dangerous pressure buildup while minimizing environmental impact through selective operation.
3Reliability
If crankcase gas is directed to the air inlet guide during engine standstill, then gas detection and leak management improve, but the risk of combustible gases reaching cylinders increases without proper control
Solution Approach 1:
The system dynamically switches between pathways based on engine operating conditions. During engine standstill, the first pathway directs crankcase gas to the air inlet guide where gas detection means can monitor for leaks. When the engine starts or under high-vapor conditions, the system transitions to directing gas through the second pathway to the atmosphere, preventing combustible gas accumulation in the cylinders while maintaining detection capability during safe operating periods.
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
The system effectively detects and manages crankcase gas leaks during engine standstill, reducing the risk of high gas concentrations externally and ensuring safe engine start-up by preventing combustible gases from reaching the cylinders.
Implementation Method 1
gas detection means positioned in the air inlet guide or open circuit conduit to detect leaks
Implementation Method 2
valve arrangement to selectively route crankcase gas between the closed and open circuits
Data Source
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AI summary
The invention provides a system for ventilation of a crankcase (217) of an internal combustion engine, the system comprising - an air inlet guide (203, 212) adapted to guide air to at least one cylinder (220) of the engine, - a closed circuit conduit (209) for guiding crankcase gas from the crankcase (217) to the air inlet guide (203, 212), - wherein the system comprises gas detection means (2181, 2182, 2183) positioned in the air inlet guide (203, 212), for detecting crankcase gas in the air inlet guide.