Pneumatic Starter Air Valve Control for Rotor Bowing Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pneumatic starter air valves for gas turbine engines face challenges in controlling air flow when actuated with non-direct current voltage signals, leading to difficulties in managing pressure regulation and rotor bowing prevention.
Innovation Solution
A method and system that utilize a first solenoid actuated by steady-state and pulse-width modulation input signals to control the pneumatic starter air valve, with an electronic circuit allowing passage of steady-state signals and preventing pulse-width modulation signals to the second solenoid, enabling pressure regulation in one mode and disabling it in another, thereby managing pressure levels and mitigating rotor bowing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a solenoid is actuated with a non-direct current voltage signal to control the pneumatic starter air valve, then the valve can be controlled for different operating modes, but the response control of the pneumatic starter air valve becomes harder
Solution Approach 1:
The control signal is segmented into two distinct types: steady-state signals for normal operation and pulse-width modulation signals for rotor bowing prevention. The electronic circuit segments the control path by routing steady-state signals to both the first solenoid and second solenoid, while pulse-width modulation signals only reach the first solenoid, thereby simplifying response control for each specific function
Solution Approach 2:
An electronic circuit acts as an intermediary between the control system and the solenoids. This intermediary selectively passes or blocks signals based on their type, ensuring that pulse-width modulation signals only actuate the first solenoid while steady-state signals actuate both solenoids, thus maintaining precise control response across different operating modes
2Reliability
If pressure regulation is enabled for engine starting, then the air pressure is properly regulated, but the system cannot quickly respond to rotor bowing conditions
Solution Approach 1:
The system dynamically switches between two operational states: during normal engine starting, the second solenoid is actuated to enable pressure regulation; when rotor bowing is detected, the pulse-width modulation signal disables the second solenoid, quickly adapting the system response to the new condition without being constrained by the pressure regulation mechanism
Solution Approach 2:
The electronic circuit is pre-configured to automatically disable pressure regulation when pulse-width modulation signals are detected, anticipating rotor bowing conditions. This preliminary action ensures that pressure regulation does not interfere with the rapid response needed for rotor bowing mitigation
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 approach improves control over the pneumatic starter air valve, enabling effective engine starting and mitigating rotor bowing by regulating pressure appropriately, enhancing the valve's response and preventing damage to the engine.
Implementation Method 1
A solenoid of the pneumatic starter air valve can be actuated with a direct current voltage signal
Implementation Method 2
allowing passage of the steady-state input signal to a second solenoid of the starter air valve to actuate the second solenoid and enable pressure regulation
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Methods and systems (200) for controlling a pneumatic starter air valve (210) of a gas turbine engine are described herein. The starter air valve (210) is controlled in a first mode of operation by actuating a first solenoid (201) of the starter air valve (210) with a steady-state input signal. Passage of the steady-state input signal to a second solenoid (202) of the starter air valve (210) is allowed, to actuate the second solenoid (202) and enable pressure regulation of the starter air valve (210). The starter air valve (210) is controlled in a second mode of operation by actuating the first solenoid (201) with a pulse-width modulation input signal. Passage of the pulse-width modulation input signal to the second solenoid (202) is prevented, to disable the pressure regulation in the second mode of operation.