Actively-Driven Bleed Source Switching for Gas Turbine Cooling
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Solution Overview
Problem
Conventional cooling methods in gas turbine engines require large amounts of airflow to maintain component temperatures within material limits, especially in high-pressure areas, due to high operating temperatures which exceed material limits.
Innovation Solution
A bleed air cooling system with multiple bleed flowpaths and valves, equipped with sensors to monitor conditions, directs airflow from different axial locations of the compressor section to specific cooling locations in the turbine section, optimizing airflow distribution based on sensed conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If large amounts of cooling airflow are used to maintain component temperatures within material limits, then component temperatures are controlled, but engine efficiency decreases and excessive airflow is required
Solution Approach 1:
The compressor discharge is divided into multiple zones along the axial direction, with bleed ports positioned at different axial locations. This segmentation allows selective extraction of cooling air from specific zones, enabling precise temperature control with reduced total airflow quantity compared to conventional single-source cooling
Solution Approach 2:
Different axial zones of the compressor discharge are utilized to provide cooling air with different thermal characteristics. By selecting bleed ports at specific axial locations, the system delivers cooling air with appropriate temperature and pressure characteristics to specific turbine section locations, optimizing cooling efficiency and reducing overall airflow requirements
2Use of energy by moving object
If high operating temperatures are used in the turbine section, then engine efficiency improves, but material limits are exceeded
Solution Approach 1:
The system replaces conventional passive cooling methods with an actively controlled cooling system using electronically operated valves and sensors. This active control system dynamically adjusts cooling airflow to maintain turbine section temperatures below material limits while allowing higher operating temperatures for improved efficiency
Solution Approach 2:
The system dynamically changes the parameters of cooling airflow (quantity, temperature, pressure) by selectively opening and closing bleed ports at different axial locations. This allows the turbine section temperature to be maintained within material limits while the engine operates at higher temperatures for improved efficiency
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 system enhances cooling efficiency by selectively diverting airflow to critical areas, reducing the need for excessive airflow and improving temperature management within the turbine section, thus extending material limits and improving engine performance.
Implementation Method 1
a bleed duct in fluid communication with the bleed ports and configured to convey the bleed airflow from the two or more bleed ports to the bleed outlet
Implementation Method 2
cooling air is often provided from the compressor to the turbine section to reduce component temperature in the turbine section
Data Source
AI summary
A bleed air cooling system for a gas turbine engine includes one or more bleed flowpaths operably connected to a bleed outlet to divert a bleed airflow from a gas turbine engine flowpath. Each bleed flowpath includes two or more bleed ports to divert a bleed airflow from a gas turbine engine flowpath, and a bleed duct in fluid communication with the bleed ports and configured to convey the bleed airflow from the two or more bleed ports to the bleed outlet. A valve is located at each bleed port of and is configured to move between an opened position and a closed position, and one or more sensors are located along the bleed flowpath to sense one or more conditions of the bleed air cooling system. The valve at a particular bleed port is moved to the opened position based on the sensed one or more conditions.