Engine Boost Control for Local Air-Fuel Ratio Smoke Reduction
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Solution Overview
Problem
Internal combustion engines face challenges in reducing smoke generation due to oxygen deficiencies in specific combustion fields, as existing methods only address average air-fuel ratios and not local variations, leading to inadequate oxygen supply and increased smoke production.
Innovation Solution
A control device and method for an internal combustion engine that calculates local air-fuel ratios and adjusts boost pressure and injection strategies, such as increasing boost pressure or switching to split injections, to ensure sufficient oxygen levels in combustion fields, thereby reducing smoke generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the average air-fuel ratio in the combustion chamber is controlled, then the overall combustion efficiency is improved, but local oxygen deficiency occurs in specific combustion fields leading to smoke generation
Solution Approach 1:
The patent applies local quality by calculating and controlling the air-fuel ratio specifically in the combustion field where fuel is injected, rather than controlling the average air-fuel ratio throughout the entire combustion chamber. This ensures that oxygen supply is optimized at the precise location where combustion occurs, preventing local oxygen deficiency and smoke generation while maintaining overall combustion efficiency.
Solution Approach 2:
The patent implements feedback control by calculating the local air-fuel ratio in the combustion field and using this information to adjust the movable vane opening degree of the supercharger. This closed-loop control system continuously monitors the local air-fuel ratio and makes real-time adjustments to ensure adequate oxygen supply, thereby preventing smoke generation while maintaining efficient combustion.
2Quantity of substance
If the movable vane opening degree is increased to increase air flow into the combustion chamber, then the oxygen supply is improved, but the boost pressure control precision deteriorates
Solution Approach 1:
The patent applies dynamics by making the movable vane opening degree adjustable and controllable based on real-time combustion field conditions. The opening degree is dynamically optimized to balance air flow quantity and boost pressure control precision, allowing the system to adapt to varying operational requirements and maintain both adequate oxygen supply and precise pressure control.
Solution Approach 2:
The patent changes the parameter of movable vane opening degree based on the calculated local air-fuel ratio. By adjusting this parameter dynamically, the system optimizes the balance between air flow quantity and boost pressure control precision, ensuring that enough oxygen reaches the combustion field while maintaining precise control over the boost pressure for efficient combustion.
3Object-affected harmful factors
If the boost pressure is increased to increase oxygen supply in the combustion field, then the smoke generation is reduced, but the energy consumption of the supercharger increases
Solution Approach 1:
The patent applies partial action by increasing the boost pressure only when and to the extent necessary to achieve the required local air-fuel ratio in the combustion field. Rather than maintaining continuously high boost pressure, the system adjusts pressure levels dynamically based on actual combustion needs, reducing unnecessary energy consumption while still preventing smoke generation when oxygen deficiency occurs.
Solution Approach 2:
The patent changes the boost pressure parameter dynamically based on the local air-fuel ratio conditions. By adjusting boost pressure only when needed to maintain proper oxygen supply, the system minimizes energy consumption while effectively preventing smoke generation. This selective parameter adjustment optimizes the balance between smoke reduction and energy efficiency.
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
Effectively reduces smoke generation by ensuring adequate oxygen levels in combustion fields through precise control of boost pressure and injection patterns, improving engine efficiency and reducing particulate matter accumulation.
Implementation Method 1
a supercharger 11 configured to supercharge the intake air
Implementation Method 2
a turbine wheel configured to rotate about a rotation axis of the turbine wheel in response to a flow force of the exhaust gas
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An internal combustion engine (1) includes a variable-capacity supercharger (11) and a fuel injection valve (4) configured to directly inject fuel into a combustion chamber (71). The variable-capacity supercharger (11) includes a movable vane (11v). An electronic control unit (80) controls a boost pressure by adjusting an opening degree of the movable vane (11v). The electronic control unit (80) calculates a local air-fuel ratio (AFL) that is an air-fuel ratio in a combustion field (NP) for the fuel injected from the fuel injection valve (4). When the local air-fuel ratio (AFL) thus calculated is an air-fuel ratio richer than a predetermined required air-fuel ratio, the electronic control unit (80) increases the boost pressure of the intake air supercharged by the supercharger (11).