Fuel Injector Plenum Design for Uniform Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing fuel injector design faces challenges in adjusting the inner baffle to a constant angle within a closed plenum, leading to uneven fuel gas flow and difficulty in uniformly mixing fuel and air due to surface unevenness and pressure loss variations across premixing tubes.
Innovation Solution
A fuel injector design featuring tapered upstream and downstream support plates with premixing tubes arranged in concentric circles, where the plenum's axial length is adjusted based on the number of premixing tubes and volume flow rate to maintain constant flow velocity, and premixing tubes protrude outward to reduce pressure loss differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an inner baffle is disposed at a constant angle to control fuel gas flow, then uniform mixing of fuel and air can be achieved, but it becomes difficult to adjust the angle within a closed plenum space
Solution Approach 1:
The inner baffle is designed as a movable component that can be adjusted to different angles. The adjustment mechanism allows the baffle angle to be changed while maintaining structural support, enabling both precise angle control and operational flexibility within the closed plenum space.
Solution Approach 2:
The plenum space is segmented into multiple zones by the adjustable inner baffle, allowing independent control of fuel gas flow paths. This segmentation enables precise angle adjustment for each baffle section to optimize mixing at different locations within the plenum.
2Reliability
If welding is performed to prevent fuel inflow between premixing tubes and inner baffle, then sealing is improved, but surface unevenness occurs on the inner baffle making fuel gas flow difficult
Solution Approach 1:
A flexible sealing ring or gasket is introduced between the premixing tubes and inner baffle to provide reliable sealing without welding. This flexible film compensates for surface unevenness while maintaining the seal, allowing smooth fuel gas flow along the inner baffle surface.
Solution Approach 2:
A sealing intermediary component is placed between the premixing tubes and inner baffle to prevent direct contact and welding. This intermediary provides both sealing function and a smooth surface for fuel gas flow, eliminating the harmful surface unevenness caused by welding.
3Ease of manufacture
If the plenum is designed as a closed space with fixed structure, then manufacturing is simplified, but it becomes difficult to adjust flow velocity and maintain uniform fuel supply
Solution Approach 1:
The closed plenum incorporates adjustable components such as movable baffles and variable-area nozzles that allow flow velocity adjustment while maintaining the overall fixed structure. These dynamic elements enable adaptation of fuel gas flow characteristics without compromising manufacturing simplicity.
Solution Approach 2:
The plenum design includes adjustable parameters such as baffle angles, opening areas, and flow path lengths that can be modified to control fuel gas flow velocity. These parameter changes allow the fixed plenum structure to adapt to different operating conditions while maintaining manufacturing simplicity.
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 design allows for easy adjustment of fuel gas flow velocity and uniform mixing of air and fuel, ensuring consistent fuel supply regardless of premixing tube positions, with improved precision in maintaining constant flow velocity and reduced pressure loss.
Implementation Method 1
an upstream support plate configured to introduce a fuel gas from a first end side into an inner side in a direction of an axis and having a shape of a tapered cylinder whose diameter gradually enlarges toward a second end side in the direction of the axis
Implementation Method 2
the fuel gas supplied from the plenum into the premixing tubes via the fuel introduction holes is mixed with the air in the premixing tubes
Implementation Method 3
the fuel gas supplied from the plenum into the premixing tubes via the fuel introduction holes is mixed with the air in the premixing tubes and is injected from second end sides of the premixing tubes
Data Source
AI summary
An injector includes: an upstream support plate into which a fuel gas is to be introduced and which has a shape of a tapered cylinder with a diameter which enlarges; a downstream support plate that defines a plenum at an inner side along with the upstream support plate; and premixing tubes, each of which is supported by the upstream support plate and the downstream support plate and is configured to introduce air. The premixing tubes are disposed in circular rows at equal intervals in a circumferential direction, and portions of the premixing tubes which are located in the plenum include fuel introducing holes.