Power augmentation for an air cycle machine of an environmental control system
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Environmental control system pack air cycle machines face challenges in maintaining minimum shaft speed during altitude operations due to low available bleed pressures, leading to flow restrictions.
Innovation Solution
A nozzle arrangement that directs a medium, such as bleed air or cabin air, to impinge on the fan of the air cycle machine, providing a pneumatic power augmentation through a regulated flow rate, which can eliminate the need for turbine flow and maintain minimum shaft speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If bleed air is supplied to turbines to maintain minimum shaft speed during altitude operation, then shaft speed is maintained above minimum value, but pack flow restriction increases
Solution Approach 1:
The invention segments the function of maintaining shaft speed from the turbine flow path by introducing a separate nozzle arrangement that directs medium impingement at the fan, allowing independent control of shaft speed maintenance without affecting pack flow restriction
Solution Approach 2:
The nozzle arrangement acts as an intermediary mechanism between the medium source and the fan, providing a controlled impingement path that transfers momentum to maintain shaft speed without requiring high bleed air pressure through the turbine flow path
2Productivity
If available bleed pressure is reduced for low pressure architecture, then pack flow restriction is minimized, but ability to maintain minimum shaft speed during altitude operation deteriorates
Solution Approach 1:
The invention employs pneumatic principles by using a nozzle arrangement to direct medium flow impingement on the fan, utilizing fluid dynamics to transfer momentum and maintain shaft speed without relying on high bleed air pressure
Solution Approach 2:
The invention changes the operational parameters by using medium impingement angle and flow rate as controllable variables to maintain shaft speed, replacing the traditional reliance on high bleed air pressure
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 nozzle arrangement effectively maintains minimum air cycle machine shaft speed at all altitude conditions, reducing flow restrictions and enhancing fan longevity by minimizing excitation and vibrations.
Implementation Method 1
at least one nozzle of the nozzle arrangement configured to direct a medium to impinge on a fan of an air cycle machine
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system (100) that comprises a nozzle arrangement (200;300;400) is provided. The nozzle arrangement (200;300;400) includes at least one nozzle (205;405) configured to supply a medium (203) at a nozzle flow rate to a fan (149) of an air cycle machine (140). The nozzle flow rate provides a pneumatic power assist or a power augmentation to a fan (149) of an air cycle machine (140). The power augmentation, in accordance with the nozzle flow rate, reduces a need for a flow across a turbine (145) of the air cycle machine (140).