Modulated Bleed Valve for Gas Turbine Surge Margin
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Solution Overview
Problem
Gas turbine engines face challenges in managing airflow through the nozzle choke area, leading to potential surges that can cause vibration and damage, as the fixed nature of the choke area restricts airflow, limiting surge margin and efficiency, especially during transient conditions.
Innovation Solution
A modulated bleed valve system that can open, close, or partially open to reroute bleed airflow aft of the nozzle choke area, increasing nozzle airflow by 3% to 5% and enhancing surge margin, while being controlled by a processor to optimize airflow based on real-time parameters during flight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed nozzle choke area is used, then the engine structure is simple, but the surge margin is limited and the engine cannot adapt to transient conditions
Solution Approach 1:
The patent applies the dynamics principle by transforming the fixed nozzle choke area into a variable configuration through the bleed valve system. The bleed valve dynamically adjusts airflow bypassing the nozzle choke, effectively creating a variable nozzle area that adapts to different operating conditions. This allows the engine to maintain optimal surge margin across transient conditions while preserving the simplicity of the physical nozzle structure.
2Stress or pressure
If bleed airflow is allowed through the turbine nozzle, then pressure is reduced, but audible emissions are generated
Solution Approach 1:
The patent applies the intermediary principle by introducing a specialized bleed valve as a mediator between the high-pressure compressor and the turbine nozzle. This intermediary component controls and modulates the bleed airflow to achieve pressure reduction while minimizing audible emissions. The valve's controlled operation allows pressure management without the harmful noise effects of uncontrolled bleeding.
3Productivity
If the nozzle choke area is fixed, then manufacturing is simple, but airflow management during transient conditions is limited
Solution Approach 1:
The patent applies segmentation by dividing the airflow control function into separate components: the fixed nozzle choke area and the modulated bleed valve system. This segmentation allows the nozzle itself to remain simple and easy to manufacture, while the bleed valve system provides the sophisticated airflow management capability needed for transient conditions. The segmentation separates the structural simplicity from the control complexity.
Data Source
AI summary
Methods and systems for a gas turbine engine comprising a modulated bleed valve are provided. The gas turbine engine may comprise a turbine nozzle coupled to a controller, a modulated bleed valve in communication with the controller, and a tangible, non-transitory memory providing instructions to the controller to perform operations. The operations may include receiving parameter values from the parameter sensor at various times, determining desired bleed airflows to flow through the modulated bleed valve at various times, and/or commanding the modulated bleed valve to assume an open configuration or a closed configuration at various times. The modulated bleed valve may be configured to allow bleed airflow to bypass a nozzle choke area of the turbine nozzle and join a nozzle airflow.