Turbine Pressure Equalization for Shaft Break Overspeed Protection
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Solution Overview
Problem
Gas turbine engines face the risk of turbine disintegration due to rapid acceleration during a shaft break event, which can cause extensive damage, and existing overspeed protection methods may not act quickly enough to prevent this.
Innovation Solution
A pressure equalization apparatus that introduces pressurized fluid directly downstream of the turbine blades to increase local pressure and reduce the pressure differential, using a regulating element to control fluid flow during a shaft break event.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing overspeed protection methods are used (introducing fluid downstream of turbine), then turbine overspeed is reduced, but the response time is insufficient to prevent turbine disintegration
Solution Approach 1:
The patent pre-positions pressurized fluid and its delivery system upstream of the turbine, ready for immediate deployment. When shaft break is detected, the fluid is instantly injected into the airflow path without requiring complex downstream fluid introduction systems, achieving faster response time while maintaining protection reliability
Solution Approach 2:
The patent uses an intermediary pressurized fluid (such as water or air) injected into the core airflow to reduce the pressure differential across the turbine. This intermediary substance acts as a mediator between the shaft break event and turbine speed control, enabling rapid energy reduction and overspeed prevention
2Reliability
If fluid is introduced downstream of the turbine to reduce mass flow rate, then turbine overspeed is mitigated, but the mechanism is too complex to act quickly enough
Solution Approach 1:
The patent extracts the fluid introduction point from the downstream region and relocates it to the upstream region before the turbine. This simplifies the system architecture by eliminating complex downstream fluid delivery mechanisms while maintaining the core function of reducing turbine power output through pressurized fluid injection into the airflow
Solution Approach 2:
The patent designs the system to automatically respond to shaft break detection without requiring complex control systems. The pre-positioned pressurized fluid system self-activates upon detection, and the geometric changes in the airflow path naturally facilitate fluid introduction, reducing the need for complex external control mechanisms
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 apparatus effectively reduces the likelihood of turbine disintegration and extensive damage by quickly mitigating turbine overspeed, enhancing safety in gas turbine engines.
Implementation Method 1
introduce a pressurised fluid into a core airflow at a region directly downstream of the turbine and proximate to the trailing edges of the turbine blades to directly increase a local pressure at the downstream region of the turbine
Data Source
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AI summary
An apparatus and method for reducing a pressure differential across a turbine 19 of a gas turbine engine 10 during a shaft break event, comprises a pressure equalization apparatus 200, 300, 400, 500, 600, 700 configured to introduce a pressurised fluid into a core airflow A at a region directly downstream of the turbine 19 in the event of a shaft break to directly increase a local pressure at the downstream region 29 of the turbine 19 and thereby reduce the pressure differential across the turbine 19. The reduction in the pressure differential may result in a reduction in the acceleration of the turbine 19.