Aircraft OBIGGS Flow Architecture for Fuel Consumption Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current on-board inert gas generating systems for aircraft face challenges in efficiently managing nitrogen-enriched air production, particularly during varying flight phases, leading to increased fuel consumption and payload penalties due to inefficient use of engine bleed air and inadequate inerting capacity.
Innovation Solution
The air separation system splits the outlet of primary and secondary air separation modules into low, mid, and high flow paths, allowing for three operational modes to match nitrogen-enriched air production with demand, optimizing system performance and reducing oxygen concentration in fuel tanks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engine bleed air is used to supply pressurized air for NEA generation, then the air separation system can operate, but engine performance decreases and fuel consumption increases
Solution Approach 1:
The system changes the operating parameters of the air separation modules by implementing multiple flow modes (low, mid, high) that adjust the flow rate of pressurized air through the ASMs. This allows the system to operate efficiently at partial capacity during cruise (reducing energy demand) while maintaining the capability to operate at full capacity when needed, thereby reducing overall fuel consumption without compromising system reliability
Solution Approach 2:
The system implements dynamic flow control with multiple operational modes that can switch between low, mid, and high flow rates based on flight phase and inerting demands. This dynamic adaptability allows the system to minimize engine bleed air usage during cruise while maintaining the ability to provide high flow rates during descent when inerting demand increases, thus resolving the contradiction between system operation and fuel consumption
2Device complexity
If a single air separation module is used, then the system is simpler, but the inerting capacity is insufficient during descent
Solution Approach 1:
The air separation system is divided into multiple air separation modules (primary and secondary ASMs) that can operate independently or in combination. This segmentation allows the system to provide low flow from a single module during cruise while combining multiple modules to deliver high flow during descent, thereby increasing inerting capacity without requiring a completely different system architecture
Solution Approach 2:
Multiple air separation modules are designed with universal functionality to perform the same air separation task. Each module can operate independently at reduced capacity or combine to provide full capacity, making the system universally adaptable to varying inerting demands across different flight phases while maintaining a relatively simple overall structure
3Productivity
If high flow rate is maintained continuously, then the inerting capacity is sufficient, but the system operates inefficiently during cruise
Solution Approach 1:
The system implements dynamic flow control with three distinct operational modes (low, mid, high flow rates) that can be switched based on flight phase and inerting demands. During cruise, the system operates in low or mid flow mode to match reduced inerting requirements, while switching to high flow mode during descent when inerting demand increases, thereby maintaining sufficient inerting capacity while optimizing system efficiency
Solution Approach 2:
The system changes the flow rate parameter of the air separation modules based on operational requirements. By implementing multiple flow modes with different flow rates, the system can adjust its output to match the varying inerting demands of different flight phases, avoiding continuous high-flow operation during cruise and thereby improving overall system efficiency while maintaining adequate inerting capacity when needed
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 configuration enhances inerting system performance, reduces system size, and minimizes fuel consumption by optimizing flow rates and thermal conditioning, thereby improving aircraft efficiency and safety during different flight phases.
Implementation Method 1
both oxygen and nitrogen are separated from the air stream due to permeation through the fiber walls
Data Source
AI summary
An air separation system and method wherein the outlet of a primary air separation module (one or more modules or bundles of fiber membranes) is split into two flow paths, a low flow path and a high flow path. The outlet of a secondary air separation module (one or more modules or bundles of fiber membranes) is split into two flow paths, a mid flow path and a high flow path, the latter being joined with the high flow of the primary air separation module. Flow along the primary low flow passes through a low-flow orifice, flow along the secondary mid-flow path passes through a mid-flow orifice, and flow along the high flow paths of both the primary and secondary air separation modules is joined together for passage through a shutoff valve and a high flow orifice. This configuration allows for three different flow modes of operation.