Adaptive EGR Control for Engine Temperature and Stability
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Solution Overview
Problem
Internal combustion engines configured to operate on alternative fuels face challenges with varying fuel burning characteristics and misfire probabilities, as well as excessive exhaust temperatures that limit engine output and risk component damage.
Innovation Solution
A method of controlling the amount of recirculated exhaust gas based on current exhaust temperature and combustion stability parameters, increasing recirculated gas when temperatures are high and reducing it when stability drops, to optimize power output while maintaining exhaust temperature within safe limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the amount of recirculated exhaust gas is increased to reduce exhaust temperature, then exhaust temperature decreases and engine output is protected, but combustion stability deteriorates and misfire probability increases
Solution Approach 1:
The patent implements dynamic adjustment of the EGR rate based on real-time monitoring of combustion stability parameters (such as cylinder pressure, temperature, or misfire detection). The control system continuously adapts the recirculated exhaust gas amount to maintain optimal combustion stability while achieving exhaust temperature reduction, rather than using a fixed EGR rate.
Solution Approach 2:
The patent employs a feedback control mechanism where combustion stability parameters are monitored and used to adjust the EGR rate. When combustion stability deteriorates due to high recirculated exhaust gas, the system reduces the EGR rate to restore stability, creating a closed-loop control system that balances temperature reduction with combustion reliability.
2Power
If engine output is increased to improve productivity, then power output increases, but exhaust temperature rises above safe limits risking component damage
Solution Approach 1:
The patent introduces recirculated exhaust gas as an intermediary substance that absorbs excess heat from the combustion process. By controlling the EGR rate, the system acts as a heat sink that reduces exhaust temperature while allowing the engine to operate at higher power outputs, thus mediating between power production and temperature management.
Solution Approach 2:
The patent changes the composition parameter of the intake charge by introducing recirculated exhaust gas, which alters the thermal properties of the combustion process. This parameter change allows the engine to sustain higher power outputs without proportionally increasing exhaust temperature, as the recirculated gas modifies the combustion characteristics.
3Device complexity
If a fixed EGR rate is used to simplify control, then device complexity is reduced, but adaptability to varying fuel compositions and operating conditions deteriorates
Solution Approach 1:
The patent enables the control system to self-adjust the EGR rate based on monitored combustion parameters without requiring complex external control mechanisms. The system uses its own operational data (combustion stability, temperature, pressure) to automatically optimize the EGR rate, making the system self-regulating and adaptable to varying conditions.
Solution Approach 2:
The patent designs the control system to handle multiple functions: temperature control, combustion stability maintenance, and adaptation to different fuel types (including alternative fuels like biogas and biodiesel). This multi-functional approach allows a single adaptive EGR control system to address various operating conditions and fuel compositions without requiring separate control mechanisms for each scenario.
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 adaptive control method enhances engine power output while preventing misfires and protecting engine components from excessive heat, even under varying fuel compositions and ambient conditions.
Implementation Method 1
increasing the amount of recirculated exhaust gas if a current exhaust temperature of the engine is above a first threshold temperature
Data Source
Figure 1
Figure 2a~2b
Figure 3~5
AI summary
A method (100) of controlling an amount of recirculated exhaust gas (Egr) to a cylinder (3) of an internal combustion engine (1) is disclosed. The method (100) comprises the steps of increasing (110) the amount of recirculated exhaust gas (Egr) if a current exhaust temperature (Tex) of the engine (1) is above a first threshold temperature (T1), and reducing (120) the amount of recirculated exhaust gas (Egr) if a combustion stability parameter (Sp) of the engine (1) drops below a first stability threshold value (S1). The present disclosure further relates to a computer program, a computer-readable medium (200), a control arrangement (5), an internal combustion engine (1), and a vehicle (40).