Fuel Tank Venting Control Using Lambda Sensor Feedback
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Solution Overview
Problem
Existing methods for venting fuel tank systems in internal combustion engines struggle to precisely control the purge gas flow and fuel-oxygen ratio, leading to inefficiencies and increased pollutant emissions.
Innovation Solution
A method and system that utilize a lambda sensor to control the purge gas delivery device and control valve based on its measurement signal, ensuring precise metering of purge gas flow and maintaining a defined fuel-oxygen ratio, thereby optimizing engine efficiency and reducing emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a lambda sensor is integrated into the exhaust stream to control purge gas flow, then the fuel-oxygen ratio control precision is improved, but the device complexity increases
Solution Approach 1:
The lambda sensor integrated into the exhaust stream is used for dual purposes: controlling the fuel injection quantity to maintain optimal combustion, and simultaneously controlling the purge gas flow rate from the fuel tank. This multi-functional use of the existing sensor avoids adding extra sensors while achieving precise fuel-oxygen ratio control during purge operations.
Solution Approach 2:
The control device continuously receives signals from the lambda sensor and dynamically adjusts both the fuel injection quantity and purge gas flow rate in real-time. This closed-loop feedback control ensures that the fuel-oxygen ratio remains within optimal ranges even as operating conditions change, resolving the contradiction between control precision and system complexity.
2Productivity
If the purge gas flow rate is increased to regenerate the fuel vapor filter more effectively, then the filter regeneration efficiency is improved, but the fuel-oxygen ratio control precision deteriorates
Solution Approach 1:
The system dynamically adjusts the purge gas flow rate based on real-time lambda sensor readings and engine operating conditions. Rather than using a fixed high flow rate, the control device modulates the purge flow to match actual regeneration needs while maintaining fuel-oxygen ratio precision, thus resolving the contradiction between regeneration efficiency and control accuracy.
Solution Approach 2:
The control device changes the purge gas flow rate parameter dynamically based on engine load, temperature, and lambda sensor feedback. By adjusting this parameter adaptively rather than statically, the system achieves effective filter regeneration without compromising fuel-oxygen ratio control precision.
3Measurement precision
If additional sensors are added to the purge gas line to improve measurement precision, then the control accuracy is improved, but the manufacturing costs increase
Solution Approach 1:
The lambda sensor in the exhaust stream performs multiple functions including combustion control and purge gas flow control. By leveraging this existing sensor's capabilities for dual purposes, the invention eliminates the need for additional dedicated sensors in the purge gas line, thereby maintaining control accuracy while reducing manufacturing costs.
Solution Approach 2:
The existing lambda sensor and control system serve the additional function of purge gas flow regulation without requiring separate measurement devices. The system uses its own existing resources (the lambda sensor) to achieve enhanced control accuracy, avoiding the need for external additions that would increase manufacturing costs.
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 precise control of purge gas flow and fuel-oxygen ratio, enhancing engine efficiency and minimizing pollutant emissions without the need for additional sensors, thus reducing manufacturing costs.
Implementation Method 1
the purge gas delivery device (46) and the control valve (42) are controlled, based on the measurement signal of a lambda sensor (56) integrated into an exhaust stream (26) of the internal combustion engine (20)
Implementation Method 2
integrating a fuel vapor filter, usually an activated carbon filter, into the vent line to absorb the fuel vapors
Implementation Method 3
ambient air can be drawn in through an ambient air inlet of the fuel vapor filter by means of a vacuum created at the point where the purge gas line connects to the fresh air/fuel mixture
Data Source
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AI summary
A method for venting a fuel tank system of an internal combustion engine is provided, wherein the fuel tank system comprises at least: a fuel tank 10, a fuel vapor filter 14 in fluid-conducting communication with an ambient outlet 44, a vent line 12 leading from the fuel tank 10 to the fuel vapor filter 14, a purge gas line 16 leading from the fuel vapor filter 14 to a fresh gas stream 18 of the internal combustion engine, and a purge gas delivery device 46 integrated into the purge gas line 16. The internal combustion engine further comprises an exhaust stream 26 with an integrated lambda sensor 56. The purge gas delivery device 46 is controlled based on the measurement signal of the lambda sensor 56 to regulate the flow rate of the purge gas in the purge gas line 16. The method can advantageously be carried out on an internal combustion engine that additionally includes a lambda controller 48.Since such an internal combustion engine should already include a lambda sensor 56 for the operation of such a lambda controller 48, the method according to the invention enables the control of the venting of the fuel tank system of the internal combustion engine without additional sensors, which has an advantageous effect on the costs of manufacturing such an internal combustion engine.