Engine Apparatus Mixed Combustion Ratio Avoidance Control
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Solution Overview
Problem
Existing engine apparatuses face challenges in avoiding abnormal combustion such as preignition and knocking when switching between gas and diesel modes or operating in a mixed combustion mode, due to changes in the mixed combustion ratio of gaseous fuels.
Innovation Solution
The engine apparatus prescribes a dangerous region for abnormal combustion based on the mixed combustion ratio of gaseous fuels and employs an avoidance control to prevent entering this region during operation, thereby ensuring stable combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the mixed combustion ratio of gaseous fuel is changed to a predetermined target ratio during mode switching, then the engine can operate in different modes (gas mode, diesel mode, mixed combustion mode), but abnormal combustion such as preignition and knocking may occur locally
Solution Approach 1:
The control unit prescribes a dangerous region map in advance that identifies combustion ratio ranges prone to abnormal combustion. Before mode switching occurs, the control unit plans the fuel injection strategy to avoid entering these predetermined dangerous regions, thereby preventing abnormal combustion before it can occur.
Solution Approach 2:
The control unit continuously monitors the actual mixed combustion ratio during operation and compares it against the prescribed dangerous region map. Based on this feedback, the control unit dynamically adjusts fuel injection amounts and timing to keep the combustion ratio outside the dangerous region, ensuring stable combustion during mode transitions.
2Ease of operation
If the amount of supplied fuel is increased monotonously to a switch threshold during mode switching, then the mode transition can be achieved, but abnormal combustion may still occur depending on the mixed combustion ratio
Solution Approach 1:
Instead of simply increasing fuel amount monotonously, the control unit changes multiple parameters simultaneously - the mixed combustion ratio is controlled to follow a specific trajectory that avoids the dangerous region, while also adjusting fuel injection timing and distribution. This multi-parameter coordination ensures mode switching occurs without entering abnormal combustion zones.
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 solution allows the engine apparatus to operate safely by avoiding abnormal combustion, ensuring reliable performance across different operation modes and mixed combustion ratios.
Implementation Method 1
an engine apparatus which is driven by at least one of a gaseous fuel and a liquid fuel being inputted into a combustion chamber
Data Source
AI summary
In an engine apparatus which is driven by at least one of a gaseous fuel and a liquid fuel being inputted into a combustion chamber, a dangerous region where abnormal combustion is predicted is preset with respect to the mixed combustion ratio of the gaseous fuel contained in fuels which are inputted into the combustion chamber, and the dangerous region is avoided when an engine is operated. For example, in the engine apparatus, when the engine is operated while the mixed combustion ratio is changed, an avoidance control which avoids the dangerous region is executed. For example, in the engine apparatus, the dangerous region is preset in a relation between the engine load and the mixed combustion ratio of the gaseous fuel.