Cylinder Deactivation for Dedicated EGR Engine Control
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Solution Overview
Problem
Engines with dedicated exhaust gas recirculation (EGR) cylinders face limitations in controlling the EGR fraction and temperature composition at the intake manifold, leading to simplified but less effective control over the system.
Innovation Solution
A system and method that deactivates primary and non-primary EGR cylinders in response to cylinder deactivation or EGR fraction deviation conditions, adjusting valve operation and fuel flow to control the EGR fraction and improve closed cycle efficiency and in-cylinder temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If dedicated EGR cylinders are used with standard fueling and controls, then the system is simplified with fewer hardware devices, but the EGR fraction is limited to a fixed ratio and control over temperature and composition is lost
Solution Approach 1:
The patent applies dynamics by enabling variable cylinder deactivation strategies where different cylinders can be deactivated independently based on real-time operating conditions. This dynamic control allows the EGR fraction to vary beyond fixed ratios, providing adaptability while maintaining system simplicity through software-based control rather than additional hardware
2Ease of operation
If all cylinders are operated in the same manner, then the system is easier to control, but the EGR fraction is limited to a simple ratio of EGR cylinders to total cylinders
Solution Approach 1:
The patent segments the cylinder control into different groups (EGR cylinders vs. non-EGR cylinders) that can be independently managed. This segmentation allows different operational modes where EGR cylinders can be selectively deactivated to adjust EGR fraction, while non-EGR cylinders maintain standard operation, thus providing both control simplicity and EGR fraction adjustability
3Adaptability or versatility
If cylinders are deactivated to change EGR fraction, then control over EGR fraction is improved, but valve operation and fuel flow control complexity increases
Solution Approach 1:
The control system uses self-service by leveraging existing engine management infrastructure (fuel injectors, valve control systems) to achieve EGR fraction adjustment. The system repurposes these existing components for dual functions: standard fuel management and EGR control, avoiding the need for dedicated EGR control hardware while maintaining adaptability
Data Source
AI summary
Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one primary exhaust gas recirculation (EGR) cylinder and a plurality of non-primary EGR cylinders. The systems, apparatus and methods control the EGR fraction by deactivation of one or more of the cylinders.