Gas Turbine Spool Power Transfer for Compression Efficiency
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Solution Overview
Problem
Gas turbine engines with electric machines on multiple spools face challenges in efficiently managing electrical power demands across different operational conditions, leading to compromises in turbomachinery design and limited flexibility in meeting varying power requirements.
Innovation Solution
A method is implemented in a gas turbine engine with high-pressure and low-pressure spools, where the first electric machine operates as a generator at maximum power rating, and excess electrical power is transferred to the second electric machine to reduce the corrected speed of the high-pressure compressor and raise the working line of the low-pressure compressor, optimizing compression efficiency during cruise conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If electric machines are coupled to only one spool, then the configuration is simpler, but the turbomachinery design must accommodate all electrical power demands leading to compromise and reduced efficiency
Solution Approach 1:
The patent divides the electrical power generation function across multiple spools (high-pressure spool and low-pressure spool), with each spool having its own electric machine. This segmentation allows each spool to be optimized for specific power demand ranges, eliminating the need for a single spool to accommodate all demands and thereby resolving the compromise in design.
Solution Approach 2:
The control system dynamically allocates electrical power demands between the high-pressure and low-pressure spools based on real-time operating conditions. This dynamic allocation allows the system to optimize compression efficiency and meet varying power demands without requiring oversizing of either spool's electric machine.
2Adaptability or versatility
If electric machines are coupled to multiple spools, then flexibility in meeting power demands is improved, but control strategy complexity increases
Solution Approach 1:
The control system continuously monitors electrical power demands and operating conditions, then adjusts the allocation between spools in real-time. This feedback mechanism enables automatic optimization of compression efficiency and power distribution without requiring complex manual control strategies.
Solution Approach 2:
The control system autonomously manages the complex task of allocating power demands between multiple spools based on pre-established optimization criteria. This self-service approach handles the control complexity internally, allowing the system to maintain flexibility while keeping the control strategy manageable through automated decision-making algorithms.
3Power
If the first electric machine operates at maximum power rating, then electrical power supply is maximized, but the high-pressure spool load increases reducing compression efficiency
Solution Approach 1:
The patent extracts excess electrical power demand from the high-pressure spool by transferring it to the low-pressure spool. When the high-pressure spool's electric machine operates at its maximum power rating, the control system redirects additional power demands to the low-pressure spool's electric machine, thereby maintaining compression efficiency while still meeting total power requirements.
Solution Approach 2:
The control system changes the operational parameters of the two spools dynamically, adjusting their power output levels based on demand and efficiency considerations. By varying the power contribution of each spool, the system can maximize electrical power supply while maintaining optimal compression efficiency through appropriate parameter selection.
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 enhances compression efficiency and flexibility in meeting electrical power demands, reducing the load on the high-pressure spool and improving overall engine performance by effectively managing power distribution between the spools.
Implementation Method 1
operating the first electric machine as a generator at the maximum power rating
Implementation Method 2
transferring excess electrical power to the second electric machine to reduce a corrected speed of a HP compressor
Data Source
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AI summary
In a gas turbine engine 101 of the type having a high-pressure (HP) spool and a low-pressure (LP) spool, methods of increasing surge margin and compression efficiency at a given thrust are provided. One method increases compression efficiency and comprises transferring mechanical power from the HP spool to the LP spool to reduce a corrected speed of a HP compressor 105 therein and raise a working line of a LP compressor 104 therein. Another method increases surge margin and comprises transferring mechanical power from the LP spool to the HP spool to increase a corrected speed of a HP compressor 105 therein and lower a working line of a LP compressor 104 therein.