Turbine Casing Heat Shield Thermal Expansion Gap Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In gas turbine engines, the gap between the blade track and the nozzle guide vane allows heat from the hot fluid to pass through and reach the turbine case, potentially damaging components and increasing maintenance costs due to high temperatures.
Innovation Solution
A heat shield is positioned between the blade track and the nozzle guide vane, which thermally expands to seal the gap, reducing heat exposure to the turbine casing and preventing hot fluid from entering the cavity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gap is left between the blade track and the nozzle guide vane, then the blade track and nozzle guide vane can thermally expand without contacting each other, but heat from hot fluid can pass through the gap to the turbine case causing damage
Solution Approach 1:
A heat shield is introduced as an intermediary component positioned between the blade track and the nozzle guide vane. This heat shield serves dual functions: it allows thermal expansion of the blade track and nozzle guide vane while blocking heat transfer from the hot fluid to the turbine case, thus resolving the contradiction between preventing contact and blocking heat exposure
Solution Approach 2:
The heat shield is designed to undergo thermal expansion during operation, allowing it to maintain the gap between the blade track and nozzle guide vane while still preventing heat transfer. The material and geometry of the heat shield are selected to expand appropriately with temperature while maintaining its protective function
2Reliability
If the gap remains open to allow thermal expansion, then component damage from contact is prevented, but maintenance costs increase due to heat damage
Solution Approach 1:
The heat shield acts as a protective intermediary that prevents hot fluid from reaching the turbine case through the gap. By blocking heat transfer while maintaining the expansion gap, it prevents heat damage to components, thereby reducing maintenance costs and improving ease of repair
3Object-affected harmful factors
If the gap is sealed to prevent heat transfer, then heat exposure to turbine case is reduced, but the blade track and nozzle guide vane may contact each other during thermal expansion
Solution Approach 1:
The heat shield serves as a mediator that maintains the necessary gap between the blade track and nozzle guide vane while blocking heat transfer. It allows thermal expansion to occur without causing contact, thus preventing both heat damage and mechanical contact issues
Solution Approach 2:
The heat shield is designed with appropriate material properties and geometry to undergo thermal expansion during operation. This expansion allows it to maintain the gap between components while still preventing heat transfer, resolving the contradiction between sealing the gap and allowing expansion
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 solution effectively reduces the temperature in the cavity, prolongs the lifespan of components, and allows for the use of less expensive materials by minimizing high-temperature exposure, thereby lowering maintenance and replacement costs.
Implementation Method 1
the heat shield and the nozzle guide vane configured to close the gap in response to a thermal expansion of the heat shield and a thermal expansion of the nozzle guide vane
Data Source
AI summary
Systems and methods for reducing heat exposure of a turbine casing in a gas turbine engine may be provided. The system may include a blade track coupled with a turbine casing with a clip. The system may further include a nozzle guide vane coupled to the turbine casing. A cavity may be formed by an end of the blade track, the clip, and a portion of the nozzle guide vane. A heat shield may be positioned between the clip and the end of the blade track in the cavity such that an edge of the heat shield and the portion of the nozzle guide vane form a gap. The heat shield and the nozzle guide vane may be positioned such that the gap closes in response to the heat shield and the nozzle guide vane thermally expanding.