Embedded Electrical Machine Cooling in Gas Turbine Engines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines face challenges in effectively cooling embedded electrical machines due to high operating temperatures, which can lead to thermal management issues and potential damage.
Innovation Solution
The implementation of a cooling system that includes a cooling duct and blower assembly, providing pressurized air through multiple airflow paths and buffer cavities around the electrical machine, both during and after engine operation, to maintain the electrical machine within a safe temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the electrical machine is embedded within the gas turbine engine, then the engine's functionality and power output are improved, but the temperature of the electrical machine increases leading to thermal management issues
Solution Approach 1:
The cooling system is divided into multiple independent airflow paths (first cooling airflow path within the enclosure, second cooling airflow path outside the enclosure) that can operate separately or together. This segmentation allows targeted cooling of different regions of the electrical machine and enclosure, effectively managing heat distribution while maintaining high power output capability.
Solution Approach 2:
Cooling air acts as an intermediary substance that transfers thermal energy from the electrical machine to the surrounding environment. The system uses buffer cavities filled with cooling air to mediate heat transfer between the electrical machine and the hot gas turbine environment, preventing direct thermal coupling and maintaining operational temperature limits.
2Temperature
If a cooling system is added to manage temperatures, then the temperature control of the electrical machine is improved, but the device complexity increases
Solution Approach 1:
The cooling system is designed to perform multiple functions: it cools the electrical machine during operation, provides thermal buffering during shutdown, and protects against heat soakback. The same enclosure and airflow paths serve both structural support and thermal management functions, reducing the need for additional dedicated cooling components and simplifying the overall system.
Solution Approach 2:
The cooling system uses a nested structure where the first cooling airflow path is contained within the enclosure, which itself is nested within the gas turbine engine. The second cooling airflow path surrounds the enclosure externally. This nested arrangement allows compact integration of multiple cooling functions within the existing engine geometry, minimizing added complexity while achieving effective temperature control.
3Temperature
If multiple cooling airflow paths and buffer cavities are implemented, then the cooling effectiveness is improved, but the manufacturing complexity increases
Solution Approach 1:
The enclosure serves dual purposes: it provides structural support for the electrical machine and simultaneously forms the boundaries of the first cooling airflow path and the first buffer cavity. By merging these functions into a single component, the system achieves effective multi-path cooling without requiring separate manufactured parts for each airflow channel, thereby reducing manufacturing complexity while maintaining cooling effectiveness.
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 solution effectively reduces the temperature of the electrical machine, preventing damage from high operating temperatures and ensuring reliable operation by maintaining the electrical machine below a peak soakback temperature of about 200°C, even after engine shutdown.
Implementation Method 1
A cooling duct provides pressurized air to the first cooling airflow path such that the air flows along both the first cooling airflow path and the second cooling airflow path
Implementation Method 2
The first cooling airflow path at least partially defines a first cooling airflow buffer cavity at least partially around the electrical machine. The second cooling airflow path at least partially defines a second cooling airflow buffer cavity at least partially around the enclosure.
Data Source
AI summary
A gas turbine engine includes a fan located at a forward portion of the gas turbine engine. A compressor section and a turbine section are arranged in serial flow order. The compressor section and the turbine section together define a core airflow path. A rotary member is rotatable with at least a portion of the compressor section and with at least a portion of the turbine section. An electrical machine is coupled to the rotary member and is located at least partially inward of the core airflow path in a radial direction. An enclosure at least partially encloses the electrical machine. The enclosure at least partially defines a first cooling airflow path within the enclosure that at least partially defines a first cooling airflow buffer cavity at least partially around the electrical machine. The first cooling airflow path is in communication with a second cooling airflow path located outside the enclosure that at least partially defines a second cooling airflow buffer cavity at least partially around the enclosure. A cooling duct provides pressurized air to the first cooling airflow path such that the air flows along both the first cooling airflow path and the second cooling airflow path providing the first cooling airflow buffer cavity and the second cooling airflow buffer cavity.