Water-Ethanol Blend Injection for Engine Knock Suppression
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Solution Overview
Problem
Existing engine systems face challenges in achieving efficient fuel economy and reducing knock issues due to the limitations of using separate fuels, which require significant infrastructure changes and may not be available in all locations, leading to variability in engine performance.
Innovation Solution
A system that uses a water or water-alcohol blend for charge cooling, allowing operation at increased compression ratios and boosting, with a controller adjusting engine parameters based on the water fraction to improve performance and accommodate variations in water delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If separate fuels (ethanol and gasoline) are used for direct injection and port injection respectively, then charge cooling effect is improved and knock limits are reduced, but infrastructure changes are required and fuel availability becomes limited
Solution Approach 1:
The patent combines water injection with ethanol direct injection into a single fluid delivery system. The water-ethanol blend is delivered through the direct injector to provide both charge cooling and combustion fuel functions, eliminating the need for separate fuel infrastructure while maintaining the thermal management benefits
Solution Approach 2:
The water-ethanol blend serves multiple functions simultaneously: it provides charge cooling through evaporation, acts as a combustion fuel, and enables operation at higher compression ratios. This multi-functionality replaces the need for separate dedicated ethanol and gasoline fuel systems
2Object-affected harmful factors
If water-alcohol blend is used for charge cooling, then knock issues are reduced and compression ratio can be increased, but engine parameters need to be adjusted based on water fraction variation
Solution Approach 1:
The control system continuously monitors engine operating parameters and adjusts the water fraction in the water-ethanol blend based on real-time feedback. This closed-loop control optimizes the blend composition to maintain knock suppression while adapting to varying engine conditions and load requirements
Solution Approach 2:
The system dynamically adjusts engine parameters including ignition timing, injection timing, and water fraction based on operating conditions. This dynamic adaptation allows the engine to optimize performance and knock suppression across different load and speed regimes without requiring manual intervention
3Adaptability or versatility
If water fraction in the fluid varies, then adaptability to different conditions is improved, but engine performance consistency becomes challenging
Solution Approach 1:
The system intentionally varies the water fraction parameter in the water-ethanol blend to adapt to different operating conditions. By controlling the water fraction within optimized ranges and adjusting related engine parameters, the system maintains performance consistency while adapting to varying thermal management requirements and load conditions
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
Enables improved engine performance by enabling operation under increased compression ratios and boosting while reducing knock issues, even when secondary fuels are not available, through the use of a water or water-alcohol blend, and adjusts engine parameters dynamically based on water content.
Implementation Method 1
uses water (or a water-alcohol blend, such as water/ethanol) injection to generate charge cooling
Implementation Method 2
using water (or a water-alcohol blend, such as water/ethanol) injection to generate charge cooling
Data Source
AI summary
A method is described for an engine having a delivery system configured to deliver fuel and a fluid to an engine cylinder, said fluid containing at least some water. In one example, an engine operating parameter may be varied based on an amount of water in said fluid, where said amount is determined based on an operating condition.