Variable-Speed Cabin Blower Control for Lower Fuel Use
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional air cycle systems in aircraft increase fuel consumption, cause over-pressure and over-temperature, rely on sensors that increase complexity and induce errors, and require tuning of controllers for desired airflow conditions.
Innovation Solution
A cabin blower control system that uses a processor to determine airflow conditions without sensors by utilizing a predetermined blower dataset to control compressor speed and variable exit vane arrangement, minimizing fuel consumption and maintaining desired pressure and temperature without measuring outlet conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional air cycle systems use sensors to determine outlet conditions, then measurement precision is improved, but device complexity increases and reliability decreases due to sensor errors
Solution Approach 1:
The patent extracts and eliminates the sensor component from the system by using a sensorless control approach. Instead of measuring outlet conditions directly with sensors, the system uses a compressor map and inlet conditions to estimate outlet conditions, thereby removing the source of sensor-related complexity and errors while maintaining the ability to control the air cycle system effectively
Solution Approach 2:
The patent introduces an intermediary calculation method that uses the compressor map as a mediator between inlet conditions and outlet conditions. Rather than directly measuring outlet parameters, the system uses the compressor map to translate inlet conditions and compressor speed into estimated outlet conditions, enabling control without direct sensors
2Measurement precision
If conventional air cycle systems use sensors to determine outlet conditions, then measurement precision is improved, but reliability decreases due to sensor errors
Solution Approach 1:
The patent extracts and eliminates the sensor component from the system by using a sensorless control approach. Instead of measuring outlet conditions directly with sensors, the system uses a compressor map and inlet conditions to estimate outlet conditions, thereby removing the source of sensor-related errors and improving reliability
Solution Approach 2:
The patent implements a feedback mechanism using the compressor map that continuously adjusts compressor speed based on the difference between desired and actual outlet conditions. This feedback loop, combined with the compressor map's characteristic curves, enables the system to maintain reliable operation without sensors by constantly adapting to changing conditions
3Stress or pressure
If conventional air cycle systems bleed air directly from the compressor, then pressure is improved, but fuel consumption increases
Solution Approach 1:
The patent applies dynamics by using a variable speed compressor driven by a motor instead of a fixed compressor driven by engine bleed air. The compressor speed can be dynamically adjusted to match the actual demand of the air cycle system, avoiding the energy waste of continuously compressing air at high pressure when less air or lower pressure is needed, thereby reducing fuel consumption while maintaining required pressure levels
4Power
If conventional air cycle systems deliver air at high pressure and high temperature, then power is improved, but temperature increases requiring additional cooling components
Solution Approach 1:
The patent applies preliminary action by pre-cooling the air in an air-to-air heat exchanger before it enters the evaporator. This preliminary cooling step reduces the temperature of the high-pressure air from the compressor, allowing the evaporator to work more efficiently and reducing the overall cooling load, thereby managing temperature without sacrificing power output
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 efficiently modulates airflow to desired conditions, reducing fuel consumption, eliminating sensor-related errors, and simplifying implementation while maintaining operational flexibility and reliability.
Implementation Method 1
The blower unit includes at least one compressor that is configured to receive an inlet airflow from the inlet and generate an outlet airflow at the outlet
Implementation Method 2
The cabin blower system may further include a heat exchanger configured to transfer heat from the outlet airflow to an ambient airflow
Data Source
AI summary
A cabin blower control system for controlling a cabin blower system includes a drive unit and a controller including a memory and a processor. The memory stores a predetermined blower dataset for a blower unit of the cabin blower system. The blower unit includes at least one compressor. The processor performs the following steps: receive a desired mass flow rate of the outlet airflow to meet a current loading on the cabin blower system; receive an inlet temperature and an inlet pressure of the inlet airflow, a compressor speed of the compressor, and a current operating condition of the blower unit; determine an estimated power consumption, a current power consumption, and an estimated operating condition of the blower unit; determine a desired speed of the compressor to operate the compressor at the desired speed.