Hydrogen ICE Dual-Mode Combustion for Load-Dependent Pre-Ignition Control
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Solution Overview
Problem
Hydrogen-fueled internal combustion engines face challenges such as high heat transfer and uncontrolled pre-ignition due to hot spots in the combustion chamber, particularly at varying engine loads and speeds.
Innovation Solution
A multi-mode operation system for hydrogen-fueled engines, switching between pre-mixed spark-ignited combustion at low loads and spark-assisted compression ignition at high loads, utilizing a centrally mounted fuel injector and co-located spark plug, with controlled ignition timing and multiple hydrogen injections to manage combustion efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pre-mixed spark-ignited combustion is used at low loads, then combustion efficiency is improved, but pre-ignition risk increases due to hot spots in the combustion chamber
Solution Approach 1:
The patent applies dynamics by switching between two combustion modes (pre-mixed spark-ignited combustion at low loads and spark-assisted compression ignition at high loads) based on operating conditions. This dynamic adaptation allows the system to optimize combustion efficiency while managing pre-ignition risks through mode selection rather than attempting to resolve the contradiction within a single mode.
2Power
If engine load and speed increase, then power output is improved, but propensity for pre-ignition increases due to higher combustion temperatures
Solution Approach 1:
The system dynamically transitions from pre-mixed spark-ignited combustion at low loads to spark-assisted compression ignition at high loads. This dynamic mode switching enables the engine to achieve higher power output at high loads while using the spark-assisted compression ignition mode to control pre-ignition risks that increase with temperature.
Solution Approach 2:
The patent changes combustion parameters by switching between different combustion modes. At high loads, the spark-assisted compression ignition mode alters the combustion parameters (ignition timing, temperature profile, pressure rise rate) to manage pre-ignition propensity while maintaining power output.
3Productivity
If centrally mounted fuel injector and co-located spark plug are used, then combustion phasing is improved, but heat transfer losses increase
Solution Approach 1:
The patent applies dynamics by switching combustion modes to manage heat transfer losses. The pre-mixed spark-ignited mode and spark-assisted compression ignition mode have different heat transfer characteristics, and the system dynamically selects the appropriate mode based on load conditions to balance combustion phasing benefits against heat transfer losses.
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 reduces pre-ignition risks, improves combustion efficiency, and minimizes NOx emissions by optimizing ignition methods based on load conditions, ensuring stable operation across varying engine loads.
Implementation Method 1
a spark plug in the glow plug position... the air fuel mixture is ignited by the ignition plug
Implementation Method 2
a centrally mounted hydrogen injector... By controlling both injection and spark timing
Implementation Method 3
spark-assisted compression ignition... fuel by the main injection is compressed and ignited
Implementation Method 4
The flame speed of hydrogen is about four to five times faster than that of gasoline, which improves efficiency through improved combustion phasing
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3C
AI summary
A method of operating a hydrogen-fueled internal combustion engine 100. The engine 100 is determined to have a mode control value, which represents a threshold torque. During operation of the engine 100, a demanded torque of the internal combustion engine 100 is determined and compared to the threshold torque. If the demanded torque is less than the threshold torque, the engine 100 is operated in a low load mode that uses spark ignition and pre-mixed combustion. If the demanded torque is greater than the threshold torque, the engine 100 is operated in a high load mode that uses compression ignition and diffusion combustion.