Thermally isolated cooling air delivery for gas turbine engines
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Solution Overview
Problem
Gas turbine engines face challenges in effectively cooling rotating components due to high temperatures, particularly in the turbine and compressor sections, where cooling air is often heated by these high temperatures, reducing efficiency.
Innovation Solution
A thermally isolated cooling air system is implemented, using a heat exchanger and insulation materials like ceramic fiber blankets to maintain cooling air temperature and prevent heat infiltration, with a control system to manage airflow and compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cooling air is supplied to rotating components in high temperature sections, then cooling function is provided, but cooling air is heated by high temperatures reducing efficiency
Solution Approach 1:
The cooling air supply system is segmented into multiple independent paths: a first cooling air path that is thermally isolated from hot sections and a second cooling air path that receives air from the first path. This segmentation allows cooling air to be delivered to rotating components without being directly exposed to high temperatures, maintaining cooling effectiveness while improving efficiency.
Solution Approach 2:
A thermally isolated cooling air path acts as an intermediary between the ambient air source and the rotating components. This intermediate path prevents direct thermal contact between hot engine sections and the cooling air, allowing efficient heat transfer for cooling while avoiding the heating effect that would reduce cooling efficiency.
2Device complexity
If cooling air path is exposed to hotter sections, then structural simplicity is maintained, but heat infiltration reduces cooling efficiency
Solution Approach 1:
The cooling air path is extracted from the hot engine sections and routed through a thermally isolated path. By separating the cooling air flow from the high temperature environment, the system eliminates heat infiltration that would otherwise reduce cooling efficiency, while the overall structure remains integrated within the engine architecture.
Solution Approach 2:
Thermal insulation materials such as ceramic fiber blankets are used to create a thermally isolated path for the cooling air. These insulation layers act as barriers that prevent heat infiltration into the cooling air path, maintaining cooling efficiency without requiring complete structural separation from the engine components.
3Loss of energy
If insulation materials are added to isolate cooling air path, then cooling efficiency is improved, but device complexity increases
Solution Approach 1:
Thin film thermal insulation materials like ceramic fiber blankets are applied to the cooling air path to prevent heat infiltration. These flexible insulation materials provide effective thermal isolation without adding significant structural complexity or bulk to the engine design, allowing efficient heat barrier protection with minimal impact on overall system complexity.
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
The system effectively cools rotating components by maintaining cooling air temperature, enhancing the efficiency and longevity of gas turbine engine components while reducing heat-related inefficiencies.
Implementation Method 1
A thermally isolated cooling air system is implemented, using a heat exchanger and insulation materials like ceramic fiber blankets to maintain cooling air temperature
Implementation Method 2
using a heat exchanger and insulation materials like ceramic fiber blankets to maintain cooling air temperature and prevent heat infiltration
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A gas turbine engine (20) includes a plurality of rotating components housed within a compressor section (24) and a turbine section (28). A first tap (104;206) is connected to the compressor section (24) and configured to deliver air at a first pressure. A heat exchanger (110;210) is connected downstream of the first tap (104;206). A flowpath is defined between a rotating surface and a non-rotating surface. The flowpath is connected downstream of the heat exchanger (110;210) and is configured to deliver air to at least one of the plurality of rotating components. At least a portion of the non-rotating surface and the rotating surface includes a base metal (150;160). An insulation material (152,154,156,162,164) is disposed on a surface along the flowpath.