Modulated Cooling Flow Scheduling for Turbine Engine Efficiency
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Solution Overview
Problem
Gas turbines face a challenge in reducing fuel consumption (SFC) without compromising stall margin, as traditional coolant airflow management is not optimized for varying operating conditions, leading to excess cooling at part power and inadequate cooling at high power operations.
Innovation Solution
The implementation of modulating valves in the coolant flow system between the compressor and turbine sections, allowing for dynamic control of coolant flow based on operating conditions, such as cruise and acceleration, to balance SFC and stall margin requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cooling airflow is increased to maintain stall margin at high power, then stall margin is improved, but specific fuel consumption worsens
Solution Approach 1:
The patent applies dynamics by making the cooling airflow variable rather than fixed. The system dynamically adjusts cooling airflow based on real-time operating conditions (power level, temperature, compressor state), allowing the engine to optimize between stall margin and fuel consumption at different operating points. This is achieved through controllable valves or variable geometry components that modulate cooling flow as needed.
Solution Approach 2:
The patent changes the parameter of cooling airflow from a constant value to a variable parameter that adapts to operating conditions. By adjusting cooling airflow parameters (flow rate, distribution) based on power level and temperature, the system resolves the contradiction between maintaining adequate cooling for stall margin and minimizing fuel consumption during cruise operations.
2Use of energy by moving object
If cooling airflow is reduced to improve specific fuel consumption at part power, then specific fuel consumption is improved, but stall margin worsens
Solution Approach 1:
The system dynamically responds to changing operating conditions by adjusting cooling airflow in real-time. During part-power cruise operations, the system reduces cooling airflow to improve fuel consumption, while during high-power or transient conditions, it increases cooling airflow to maintain stall margin. This dynamic adaptation resolves the contradiction by making cooling flow conditional rather than fixed.
Solution Approach 2:
The patent implements feedback control where the system monitors operating parameters (power level, temperature, compressor state) and adjusts cooling airflow accordingly. This closed-loop control ensures that cooling flow is optimized for fuel consumption during stable cruise while automatically increasing when stall margin becomes compromised, resolving the contradiction through continuous adaptation.
3Temperature
If traditional high power coolant airflow requirements are maintained during cruise, then turbine temperature protection is improved, but specific fuel consumption worsens due to excess cooling
Solution Approach 1:
The patent applies local quality by providing different cooling airflow levels to different turbine sections or different areas of the turbine based on local thermal requirements. Rather than uniformly cooling the entire turbine at high power levels, the system selectively applies cooling where and when needed, reducing excess cooling during cruise while maintaining adequate temperature protection during high-power operations.
Solution Approach 2:
The system dynamically adjusts cooling airflow based on actual turbine temperature requirements rather than using fixed high-power settings. During cruise operations with lower turbine temperatures, cooling flow is reduced to minimize fuel consumption impact. During high-power operations with elevated turbine temperatures, cooling flow is increased to maintain temperature protection, resolving the contradiction through condition-based adaptation.
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 reduces fuel consumption by optimizing coolant flow during part power operations while maintaining adequate stall margin during high power and acceleration conditions, thereby improving overall engine efficiency and resource utilization.
Implementation Method 1
coolant flow within the gas turbine to improve overall specific fuel consumption (SFC) while not compromising stall margin
Data Source
AI summary
A turbine engine includes a compressor, and high and low pressure turbines. The configuration includes a mid-compression station which can be, in the case of a single compressor in the middle of that compressor, or at the exit of the first compressor in the case of two compressors. Also, there is an exit pressure station at the exit of the compression system. A first gas flow line is interposed between the mid-compression station of the compressor and the low pressure turbine, and a second gas flow line is interposed between the exit pressure station of the compression system and the high pressure turbine. A first valve is coupled to the first gas flow line and modulates a low pressure flow rate of coolant in the first gas flow line, and a second valve is coupled to the second gas flow line and modulates a high pressure flow rate of coolant in the second coolant flow line. A controller is configured to operate the first and second valves based on an operating condition of the turbine engine so as to improve the specific fuel consumption while ensuring acceptable stall margin.