Internal Combustion Engine Valve Timing Control for Part Load Efficiency
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Solution Overview
Problem
Large internal combustion engines, particularly those in marine applications, are inefficient during slow steaming operations, which occur at loads below maximum capacity, leading to untapped potential for engine efficiency and increased fuel consumption.
Innovation Solution
A control system for internal combustion engines that adjusts inlet valve actuation and fuel injection to optimize operation in part load modes, with specific closing angles and injection timings for engine loads between 40% to 75% of maximum load, and transitions to high load modes above this range, allowing for earlier inlet valve closure and adjusted fuel injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the internal combustion engine operates at part load (below maximum capacity), then fuel consumption increases and efficiency decreases, but the engine cannot maintain optimal performance across all load conditions
Solution Approach 1:
The patent implements dynamic valve actuation timing that adapts to different load conditions. The control system adjusts the inlet valve closing angle based on the current load, transitioning from earlier closing at part load to later closing at high load, allowing the engine to optimize efficiency across varying operating conditions rather than being fixed at a single timing configuration
Solution Approach 2:
The patent changes the valve actuation timing parameter based on load conditions. Specifically, the inlet valve closing angle is varied between part load mode (earlier closing) and high load mode (later closing), enabling the engine to achieve optimal fuel consumption at different operating points by adjusting this critical timing parameter
2Productivity
If the inlet valve closes earlier in part load mode, then fuel consumption is reduced and efficiency is improved, but the valve timing must be dynamically adjusted based on load conditions
Solution Approach 1:
The control system serves multiple functions: it monitors engine load conditions, determines the appropriate operating mode (part load or high load), selects the corresponding valve timing strategy, and actuates the variable valve timing mechanism. This multi-functional approach consolidates what could be separate complex systems into a unified control architecture that achieves high efficiency across different operating conditions
3Power
If the engine is optimized for maximum load performance, then power output is maximized, but performance and efficiency deteriorate during slow steaming operations at lower loads
Solution Approach 1:
The patent segments the operating range into distinct modes: part load mode (up to approximately 75% of maximum load) and high load mode (above 75% of maximum load). Each mode has optimized valve timing parameters, allowing the engine to achieve peak efficiency in each segment while maintaining the capability to deliver maximum power when needed, rather than being compromised across the entire operating range
Data Source
AI summary
A control system is disclosed for operating an internal combustion engine. The control system includes a control unit configured for providing a part load mode that is optimized for slow operation of the engine at loads up to an upper part load limit in the range from 40% to 75% of a maximum engine load. The control unit is also configured for providing a high load mode for engine loads above the upper part load limit. In the part load mode, at least one inlet valve is closed at a closing angle later than in the high load mode.