Hydraulic Starter Torque Modulation for Gas Turbine Light-Off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines face challenges in efficiently transitioning from startup to light-off conditions due to inconsistent torque output from hydraulic starters, which can lead to prolonged engine startup times and reduced likelihood of successful light-off, especially under varying altitude and temperature conditions.
Innovation Solution
A starter assembly with a fluid-actuated starter and a controller that modulates the flow rate of fluid to adjust torque output based on predefined rotational speed thresholds, allowing for reduced torque during initial startup and increased torque as the engine approaches light-off conditions, thereby optimizing the engine's operational conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If maximum torque is applied during engine startup, then the engine can overcome initial inertia and start rotating, but the startup time is prolonged and successful light-off is less likely
Solution Approach 1:
The hydraulic starter system dynamically adjusts torque output during the startup sequence by modulating fluid flow rate. The controller varies the flow rate from maximum at initial startup to reduced levels as the engine approaches light-off conditions, optimizing both acceleration and fuel efficiency throughout the transition.
Solution Approach 2:
The system changes the operational parameters of the hydraulic starter by adjusting fluid flow rate based on engine rotational speed and light-off conditions. This parameter modulation allows the starter to provide high torque when needed and reduce torque to minimize startup time and improve light-off probability.
2Force
If high fluid flow rate is supplied to the hydraulic starter, then maximum torque output is achieved, but startup efficiency is reduced due to prolonged startup duration
Solution Approach 1:
The controller implements periodic modulation of fluid flow rate to the hydraulic starter, alternating between high flow rates for torque generation and reduced flow rates for efficiency. This periodic action optimizes the balance between force output and startup efficiency throughout the engine light-off sequence.
Solution Approach 2:
The system applies partial torque (reduced fluid flow rate) during phases where maximum force is not required, specifically after initial engine rotation is achieved and before light-off. This partial action maintains sufficient torque to overcome compression while reducing overall startup time and improving efficiency.
3Ease of operation
If the hydraulic starter operates at constant torque, then the system is simple to control, but it cannot adapt to varying altitude and temperature conditions affecting light-off
Solution Approach 1:
The controller receives feedback regarding engine operational conditions and light-off status to dynamically adjust fluid flow rate to the hydraulic starter. This feedback mechanism enables the system to adapt to varying altitude and temperature conditions while maintaining automated control, resolving the contradiction between control simplicity and environmental adaptability.
Data Source
AI summary
A starter assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a fluid-actuated starter coupled to a spool, and a controller operable to cause a reduction in torque output of the starter in response to determining that a first threshold is met. The first threshold relates to an engine operational condition. A method for starting a gas turbine engine is also disclosed.