Corona Ignition System for Compression Ignition Control
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Solution Overview
Problem
The challenge in internal combustion engines is to achieve controlled and rapid ignition in compression ignition combustion mode, as conventional spark plugs are inadequate for precise timing and influence over the combustion process, especially in lean-burn operations where NOx emissions are high, requiring complex exhaust treatment.
Innovation Solution
A corona ignition system is used to generate a non-thermal plasma, initiating self-ignition by forming radicals along corona filaments, allowing for precise control of ignition timing and location within the combustion chamber, potentially replacing conventional spark plugs for both compression ignition and external ignition modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional spark plugs are used for ignition in compression ignition mode, then the ignition system is simple, but the ignition timing control is imprecise and combustion process influence is insufficient
Solution Approach 1:
The patent applies parameter changes by utilizing the variable capacitance effect of the piezoelectric ceramic material. The capacitance changes in response to pressure variations within the combustion chamber, enabling the system to detect compression state and control ignition timing precisely without complex mechanical structures. This transforms a physical parameter (capacitance) into a control signal for precise ignition timing.
Solution Approach 2:
The patent replaces conventional mechanical ignition control systems with a piezoelectric-based capacitive sensing system. Instead of using complex mechanical linkages or electronic sensors with multiple components, the invention uses the inherent piezoelectric effect and capacitance changes of a ceramic material to directly sense and control ignition timing, simplifying the overall system while improving precision.
2Use of energy by moving object
If stratified lean combustion is used to reduce fuel consumption, then fuel efficiency improves, but nitrogen oxide emissions increase requiring complex exhaust treatment
Solution Approach 1:
The patent implements feedback control by using the piezoelectric capacitor to continuously monitor the compression state and combustion chamber pressure. This real-time feedback enables precise control of ignition timing and combustion process, allowing the engine to operate in compression ignition mode with lean mixtures while maintaining low NOx emissions through optimized combustion phasing and duration.
Solution Approach 2:
The invention changes the combustion mode parameter from conventional spark-ignited stratified combustion to compression ignition. This parameter change fundamentally alters the combustion chemistry and timing, enabling lean operation without the high NOx emissions associated with traditional lean-burn spark-ignited engines, as compression ignition provides better control over peak combustion temperatures.
3Object-generated harmful factors
If compression ignition combustion mode is used to reduce NOx emissions, then emissions improve, but combustion process control becomes difficult due to lack of singular control parameter
Solution Approach 1:
The patent establishes feedback control for compression ignition by using the piezoelectric capacitor to sense compression pressure and combustion chamber conditions. This feedback provides the missing control information, allowing the singular control parameter (ignition timing) to be precisely adjusted based on real-time chamber state, thereby enabling effective combustion process control in compression ignition mode.
Solution Approach 2:
The invention replaces the need for multiple control parameters with a piezoelectric-based sensing and control system that provides precise timing control through electrical signals. The piezoelectric material's response to mechanical pressure is converted into electrical signals that directly control ignition, simplifying the control interface while improving controllability.
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 enables precise control over ignition timing, reduces NOx emissions, eliminates the need for expensive exhaust treatment, and simplifies the combustion process control, allowing for stable engine operation across varying conditions.
Implementation Method 1
the capacitor is formed using a piezoelectric ceramic and changes in capacitance occur as a function of the compression pressure within the combustion chamber
Implementation Method 2
A corona ignition system is used to generate a non-thermal plasma, initiating self-ignition by forming radicals along corona filaments
Data Source
AI summary
The invention relates to an internal combustion engine which can be operated in a compression ignition combustion mode at least under certain operating conditions, wherein the combustion mixture present in the combustion chamber achieves auto-ignition conditions during the course of the process and auto-ignites. The internal combustion engine comprises a trigger unit for triggering the auto-ignition during the compression ignition combustion mode before reaching the conditions for auto-ignition. The invention is characterized in that the trigger unit is designed as a corona ignition system and can be operated as a trigger unit for triggering the auto-ignition during the compression ignition combustion mode particularly by generating non-thermal plasma.