Dual Fuel Engine Knock Control via Adaptive Fuel Blending
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dual fuel engine systems face challenges such as premature detonation, inadequate thermal energy for power output, air availability issues, and increased emissions due to varying load conditions and substandard gaseous fuel quality, which limit their widespread adoption in vehicles.
Innovation Solution
A dual fuel engine system with a control unit that adjusts gaseous fuel flow and ignition timing based on knock sensor feedback, allowing for operation on varying fuel grades and maximizing gaseous fuel use while minimizing liquid fuel consumption and emissions, using a combination of gaseous and liquid fuel supplies with a knock sensor to detect and adapt to fuel quality and engine demands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If gaseous fuel is injected into the intake air of a diesel engine, then emissions (NOx, particulates) are reduced and fuel economy is improved, but engine power is reduced due to lower cetane value and inadequate thermal energy
Solution Approach 1:
The patent combines gaseous fuel injection system with the existing diesel fuel injection system to create a dual-fuel engine. The gaseous fuel is injected into the intake air stream and mixed with air, while diesel fuel is injected directly into the combustion chamber. This merging allows the engine to utilize both fuel types, where gaseous fuel reduces emissions and diesel fuel maintains engine power through compression ignition.
Solution Approach 2:
The diesel engine is modified to perform multiple functions: it can operate on diesel fuel alone, gaseous fuel alone, or a combination of both. The control system enables the engine to adapt to different operating conditions and fuel availability, maximizing the use of gaseous fuel for emissions reduction while using diesel fuel to maintain power output when needed.
2Object-generated harmful factors
If the amount of diesel fuel injected is reduced to lower emissions, then NOx and particulate emissions are reduced, but engine power is reduced
Solution Approach 1:
Gaseous fuel acts as an intermediary energy source that supplements diesel fuel injection. By injecting gaseous fuel into the intake air, the system provides additional thermal energy and combustion contribution, allowing reduced diesel injection rates while maintaining engine power output and further reducing emissions.
3Object-generated harmful factors
If gaseous fuel flow volume is increased to maximize emissions reduction, then emissions are reduced, but knock occurs due to substandard fuel quality and varying load conditions
Solution Approach 1:
The control system continuously monitors engine operating conditions including load, speed, and combustion characteristics. Based on this feedback, the system dynamically adjusts the gaseous fuel injection rate and timing to prevent knock while maximizing emissions reduction. The control unit modifies gaseous fuel supply in response to detected knock conditions, balancing emissions performance with engine reliability.
Solution Approach 2:
The gaseous fuel injection system is designed to be dynamically adjustable based on varying engine load conditions and fuel quality. The injection rate, timing, and duration are continuously modified to match operating conditions, allowing the system to prevent knock at high loads while maximizing emissions reduction at lower loads where knock is less likely.
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 system reduces NOx, particulate, and CO2 emissions by optimizing gaseous fuel use and adapting to different fuel grades, ensuring efficient engine operation and power output while minimizing diesel fuel usage.
Implementation Method 1
at least one knock sensor arranged to detect knock in each combustion chamber
Implementation Method 2
During the compression stroke of the piston, the pressure and temperature of the mixture are increased
Implementation Method 3
Near the end of the compression stroke, a small quantity of pilot diesel fuel from the engine's existing diesel fuel injection system is injected into the cylinder. The pilot diesel ignites due to compression
Data Source
AI summary
A dual fuel engine operates on a gaseous fuel and a liquid fuel. The engine comprises a supply of gaseous fuel controlled by a first valve, a supply of compression ignitable liquid fuel controlled by a second valve, a control unit for controlling the supply of gaseous fuel and liquid fuel to each combustion chamber in the engine, and at least one knock sensor arranged to detect knock in each combustion chamber and to transmit an output signal proportional to the detected level of knock to the control unit. If knock is detected, the amount of gaseous fuel injected will be reduced while the amount of liquid fuel will be increased. The engine control system will subsequently adapt to the lower grade fuel and perform a calibration to operate as close as possible to the knock limit for the particular fuel.