Auto-ignition Engine Cylinder Groups with Variable Compression Ratios
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Solution Overview
Problem
Current diesel engines with partial deactivation methods for auto-ignition internal combustion engines have limitations in optimizing fuel consumption and efficiency, particularly during part-load operations, as they do not effectively manage load distribution and heat losses across cylinder groups with different compression ratios.
Innovation Solution
The implementation of at least two cylinder groups with different compression ratios, where one group operates at a higher compression ratio for low loads and the other at a lower compression ratio for high loads, allowing for dynamic activation and deactivation of cylinders based on load conditions to optimize fuel efficiency and reduce wall heat losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If partial deactivation of cylinders is implemented to improve fuel efficiency during part-load operation, then specific fuel consumption is reduced, but the engine cannot effectively adapt to varying load conditions with optimal compression ratios
Solution Approach 1:
The engine is divided into two separate cylinder groups (first and second groups), each with different compression ratios. This segmentation allows independent operation of cylinder groups based on load conditions, enabling the engine to optimize fuel efficiency across different operating ranges by activating only the appropriate group.
Solution Approach 2:
The engine implements dynamic switching between different cylinder groups based on real-time load conditions. The control system can activate or deactivate entire cylinder groups, allowing the engine to adapt its compression ratio to match current operating demands, thereby maintaining optimal fuel efficiency across varying loads.
2Device complexity
If a single compression ratio is used for all cylinders, then the engine structure is simpler, but fuel consumption increases during part-load operation due to suboptimal compression for the current load
Solution Approach 1:
Instead of using a single compression ratio for all cylinders, the engine segments cylinders into two groups with different compression ratios. This allows each group to be optimized for specific load ranges, improving fuel consumption characteristics without requiring complex individual cylinder control.
Solution Approach 2:
The engine changes the compression ratio parameter by switching between different cylinder groups based on load conditions. During part-load operation, the high-compression group can be activated to optimize fuel consumption, while during full-load operation, the low-compression group becomes more suitable, effectively adapting the compression parameter to operating conditions.
3Reliability
If all cylinders remain active during part-load operation, then the engine can handle load variations, but wall heat losses increase reducing overall efficiency
Solution Approach 1:
The engine extracts or removes entire cylinder groups from operation when they are not needed for the current load conditions. During part-load operation, one cylinder group can be completely deactivated, eliminating wall heat losses from that group while maintaining sufficient power output from the active group, thereby improving overall efficiency.
Solution Approach 2:
Instead of partially deactivating individual cylinders within a group, the engine applies partial action by deactivating entire cylinder groups. This approach is sufficient for handling part-load conditions while maximizing efficiency gains by completely eliminating heat losses from deactivated cylinders, rather than partially reducing them.
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 enhances fuel efficiency by adjusting compression ratios to match load conditions, reducing specific fuel consumption and minimizing heat losses, thereby improving overall engine performance across various load ranges.
Implementation Method 1
at least two groups are characterized by different compression ratios εi, at least one cylinder of a first group having a compression ratio ε1 and at least one cylinder of a second group having a compression ratio ε2
Data Source
AI summary
Methods and systems are provided for optimizing the operation of a multi-cylinder auto-ignition internal combustion engine. In one example, cylinders of the auto-ignition internal combustion engine may form two groups of cylinders, where one group of cylinders has a larger compression ratio, smaller width, and smaller volume than the other group of cylinders, and where at least one cylinder of the other group is configured as a switchable cylinder that is deactivated in a load-dependent manner. By configuring the cylinders in multiple groups based on compression ratios, and operating the cylinders in a load-dependent manner, fuel consumption may be optimized.