Multi-Needle Fuel Injector for Dual-Fuel Combustion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fuel injection systems in internal combustion engines face challenges in efficiently managing the injection of both liquid and gaseous fuels, particularly in dual-fuel engines, where precise control over fuel flow rates and pressures is necessary to optimize combustion efficiency and engine performance.
Innovation Solution
A multi-needle fuel injector design is introduced, featuring a nozzle tip with multiple injection holes, a first needle biased by a first biasing member within a control volume, and a second needle surrounding the first needle, biased by a second biasing member. This design allows for controlled fuel flow through different sets of holes based on the energization duration of a needle actuator, enabling efficient injection of both pilot and main fuel quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single needle is used in the fuel injector, then the device complexity is reduced, but the precision of fuel flow control and injection timing is insufficient
Solution Approach 1:
The fuel injector needle is segmented into multiple independent needles (first needle, second needle, third needle), each capable of independent movement and fuel injection control. This segmentation allows precise control over different fuel injection stages (pilot injection, main injection, post injection) while maintaining separate control mechanisms for each needle, thereby achieving high fuel flow control precision without excessive structural complexity.
Solution Approach 2:
The multiple needles are designed with different lengths and are capable of dynamic, independent movement at different rates. The first needle moves faster than the second needle, and the second needle moves faster than the third needle, allowing dynamic control of fuel injection timing and duration. This dynamic capability enables precise control of fuel flow rates and injection sequences, resolving the contradiction between precision and complexity.
2Duration of action of moving object
If multiple needles with different lengths are used, then the control over fuel injection timing and duration is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The different needle lengths are predetermined during manufacturing to establish a hierarchical movement sequence. The first needle (longest) is designed to move first, followed by the second needle, and then the third needle (shortest). This preliminary design of length differentials creates built-in timing control that compensates for manufacturing tolerances, as the sequential activation is determined by the structural design rather than requiring extremely tight length tolerances.
Solution Approach 2:
The invention changes the parameter of needle length to create functional differentiation among the needles. By varying the lengths of the first, second, and third needles, the system achieves different injection durations and timing characteristics. This parameter change approach allows control over injection duration without requiring extremely tight manufacturing tolerances, as the length differences themselves are the control mechanism.
3Productivity
If a multi-needle system is implemented, then the fuel atomization and mixing efficiency is improved, but the device complexity increases
Solution Approach 1:
The control system is segmented into multiple independent control volumes (first control volume, second control volume, third control volume), each associated with a specific needle. This segmentation allows independent control of each injection stage, enabling optimized fuel atomization and mixing for different injection phases (pilot, main, post). The segmented control structure achieves high combustion efficiency while keeping the control architecture manageable through clear functional separation.
Solution Approach 2:
The multi-needle system provides multi-functionality by enabling different injection modes (pilot injection for gaseous fuel combustion, main injection for liquid fuel, post injection for emission control) using a single injector assembly. This universal design achieves improved combustion efficiency across various operating conditions without requiring multiple separate injectors, thereby balancing productivity improvement with acceptable device complexity.
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 multi-needle fuel injector system enhances combustion efficiency by precisely controlling fuel flow rates and pressures, improving atomization and mixing of air/gaseous and liquid fuels, thereby optimizing engine performance and efficiency across various operating conditions.
Implementation Method 1
a first needle biased against the nozzle tip via a first biasing member positioned within a first control volume; and a second needle surrounding a portion of the first needle and biased against the first needle and the nozzle tip via a second biasing member positioned within a second control volume
Data Source
AI summary
Various methods and systems are provided for a fuel injector. In one example, a fuel injector includes a nozzle tip including a plurality of injection holes, a first needle biased against the nozzle tip via a first biasing member positioned within a first control volume, and a second needle surrounding a portion of the first needle and biased against the first needle and the nozzle tip via a second biasing member positioned within a second control volume. A needle actuator may be energized for different durations of time in order to move one or more of the first needle and the second needle relative to the nozzle tip.