Per-Cylinder Combustion Control with Exhaust Temperature and NOx Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing internal combustion engines face challenges in balancing combustion across multiple cylinders, particularly in hydrogen engines, leading to variations in air-fuel ratios and stratification, which increase NOx emissions and the likelihood of engine knock and misfire, while existing control systems rely on single parameters that are inadequate for precise combustion control.
Innovation Solution
A control system utilizing both exhaust temperature and NOx sensors to measure and adjust operational parameters such as air-fuel ratio, spark timing, and exhaust gas recirculation fraction for each cylinder to balance combustion performance and reduce NOx emissions, while avoiding incomplete combustion and engine knock.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single parameter control systems are used, then device complexity is reduced, but combustion control precision deteriorates
Solution Approach 1:
The control system is segmented into multiple independent control loops, with each cylinder having its own control channel that independently processes exhaust temperature and NOx sensor data. This allows precise per-cylinder control without requiring a completely complex integrated system, as each segment operates semi-autonomously while contributing to overall engine performance.
Solution Approach 2:
The control system uses universal dual-sensor feedback (exhaust temperature and NOx sensors) across all cylinders, where the same sensing and control methodology is applied universally to each cylinder. This multi-functional approach enables precise control of multiple cylinders using consistent principles, reducing overall system complexity while maintaining high precision through standardized reusable control logic.
2Object-generated harmful factors
If operational parameters are adjusted to reduce NOx emissions, then harmful factors are reduced, but combustion performance may deteriorate
Solution Approach 1:
The system implements closed-loop feedback control using both exhaust temperature sensors and NOx sensors for each cylinder. The controller continuously monitors actual exhaust temperature and NOx levels, compares them against target values, and dynamically adjusts operational parameters (fuel injection timing, air-fuel ratio, EGR rate) to maintain optimal combustion. This feedback mechanism ensures NOx reduction does not compromise combustion performance, as the system automatically compensates to maintain reliable combustion while reducing emissions.
Solution Approach 2:
The control system dynamically changes multiple operational parameters simultaneously rather than relying on single parameter adjustment. By coordinating changes in fuel injection timing, air-fuel ratio, and exhaust gas recirculation rate based on dual-sensor feedback, the system achieves NOx reduction while maintaining combustion performance. The multi-parameter adjustment approach allows the system to navigate the complex trade-off between emissions and combustion reliability effectively.
3Reliability
If combustion is optimized for one cylinder, then combustion performance is improved, but variations among cylinders increase
Solution Approach 1:
The control system treats each cylinder as a separate controlled entity with independent feedback loops. Each cylinder's exhaust temperature and NOx sensors provide localized feedback that is processed independently, allowing the controller to identify and correct cylinder-specific deviations. This segmentation enables the system to maintain consistent combustion across all cylinders by addressing each one's unique characteristics rather than applying uniform control, thereby reducing inter-cylinder variations while maintaining overall performance.
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 achieves precise control of combustion across multiple cylinders, reducing NOx emissions and minimizing variations, thereby improving engine efficiency and performance.
Implementation Method 1
a temperature sensor configured to measure an exhaust temperature from a cylinder of the internal combustion engine
Implementation Method 2
a NOx sensor configured to measure an exhaust NOx amount from the cylinder
Implementation Method 3
control the one or more of the plurality of operational parameters based on the current combustion performance
Implementation Method 4
an exhaust gas recirculation fraction
Data Source
AI summary
A control system for an internal combustion engine includes a temperature sensor configured to measure an exhaust temperature from a cylinder of the internal combustion engine, a NOx sensor configured to measure an exhaust NOx amount from the cylinder, and a controller operably connected to the temperature sensor and the NOx sensor. The controller is configured to: receive the measured exhaust temperature from the temperature sensor and the measured exhaust NOx amount from the NOx sensor, calculate a current combustion performance of the cylinder based on the measured exhaust temperature and the measured exhaust NOx amount, determine whether to adjust one or more of a plurality of operational parameters, and control the one or more of the plurality of operational parameters based on the current combustion performance.