Ignition Device Limiting Diode Prevents Hydrogen Backfire
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Solution Overview
Problem
The use of hydrogen as a fuel in internal combustion engines poses a risk of unexpected spark plug discharges, leading to backfires and abnormal combustion due to its high combustibility at low temperatures, which existing ignition devices fail to prevent effectively.
Innovation Solution
An ignition device incorporating an ignition coil with a primary and secondary coil, a power supply, a switching element, and a limiting diode, where the limiting diode, either a Zener or avalanche diode, is forward-biased to prevent discharge at abnormal timings by reducing the ON-state voltage in the secondary coil and managing residual energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If hydrogen is used as fuel in the internal combustion engine, then low carbon society can be realized, but discharge may occur in the spark plug at unexpected timing causing backfire or abnormal combustion
Solution Approach 1:
A limiting diode is introduced as an intermediary component in the secondary circuit to control voltage. The diode limits the voltage to a predetermined level, preventing unexpected discharge while allowing normal ignition operation with hydrogen fuel
Solution Approach 2:
The voltage parameter in the secondary circuit is changed from uncontrolled to limited by introducing the limiting diode. This parameter change ensures that voltage remains below the breakdown threshold during normal operation, preventing abnormal discharge when using hydrogen fuel
2Device complexity
If a conventional ignition device is used, then simple structure is maintained, but discharge occurs at abnormal timing due to high ON-state voltage
Solution Approach 1:
The limiting diode serves as an intermediary element added to the secondary circuit, providing voltage limitation functionality with minimal impact on the overall device structure
Solution Approach 2:
The limiting diode is configured with asymmetric orientation in the circuit, allowing current flow in one direction while blocking reverse current, thereby limiting voltage spikes during specific operational phases
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 solution effectively prevents discharge at the spark plug during normal operation and reduces the risk of abnormal ignition, ensuring safe and controlled combustion in engines using hydrogen fuels.
Implementation Method 1
an ignition coil, a power supply device, a switching element, a spark plug, and a limiting diode. The ignition coil is formed by electromagnetic coupling of a primary coil and a secondary coil
Implementation Method 2
The limiting diode includes a Zener diode or an avalanche diode that is interposed in a first connecting wire or a second connecting wire
Data Source
AI summary
An ignition device for an internal combustion engine that uses fuels including hydrogen. The ignition device includes an ignition coil including a primary coil and a secondary coil, a power supply device, a switching element, a spark plug, and a limiting diode. The switching element performs switching between passage and interruption of a primary current. The spark plug causes discharge at a gap, based on a high voltage induced at the secondary coil. The limiting diode includes a Zener diode that is forward-biased when oriented in a direction from the one end to the other end of the secondary coil. A breakdown voltage of the limiting diode is higher than the maximum value of an ON-state voltage obtained by multiplication of a value of a direct-current voltage applied to the primary coil by a ratio of the number of turns of the secondary coil to that of the primary coil.