Cross-over Purge Flow System for Turbomachine Wheel Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing turbomachine purge systems rely on a single stage pressure drop to drive air flow, which may not effectively manage high temperatures and temperature gradients in rotor components, leading to low cycle fatigue, embrittlement, and reduced system performance and durability.
Innovation Solution
A cross-over purge flow system is implemented in turbomachine wheel members, featuring two independent sets of purge circuits that direct purge flows in distinct directions, allowing for increased pressure drops and enhanced cooling, with the first flow passing through a conduit from the outer surface to the central bore and the second flow passing from the central bore to the outer surface, creating a cross-over purge flow zone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a single stage pressure drop is used to drive purge air flow, then the system structure is simple, but the temperature management effectiveness is insufficient leading to high rotor wheel temperatures and temperature gradients
Solution Approach 1:
The purge system is segmented into multiple independent purge circuits (first plurality and second plurality) with distinct flow paths. Each circuit handles specific temperature zones and flow directions, allowing independent optimization of temperature management in different regions of the rotor wheel while maintaining overall system effectiveness.
Solution Approach 2:
The invention introduces a cross-flow dimension by directing purge flows in opposite directions through the rotor wheel thickness. The first purge flow moves in one direction while the second purge flow moves in the opposite direction, creating a three-dimensional cooling pattern that enhances temperature management effectiveness beyond single-direction cooling.
2Reliability
If multiple independent purge circuits are implemented, then temperature management is improved, but the device complexity increases
Solution Approach 1:
The rotor wheel structure serves multiple functions simultaneously: it acts as the rotating component of the turbomachine and as the housing for multiple independent purge circuits. The wheel body integrates both the first and second pluralities of purge circuits, eliminating the need for separate external cooling systems and reducing overall device complexity despite the enhanced cooling capability.
Solution Approach 2:
Multiple purge circuits that are fluidly isolated from each other are merged into a single rotor wheel structure. The first plurality of purge circuits and second plurality of purge circuits coexist within the same wheel body, sharing the structural space while maintaining independent fluid paths, thereby improving reliability without proportionally increasing external system complexity.
3Duration of action of stationary object
If higher purge flows are used to reduce temperature gradients, then component life is extended, but the pressure drop requirements increase
Solution Approach 1:
Different purge circuits are directed to different regions of the rotor wheel to address local temperature gradients. The first purge flow targets specific high-temperature zones while the second purge flow addresses opposite regions, allowing optimized pressure drop distribution across different areas rather than applying uniform high pressure throughout the entire wheel.
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 configuration enables higher purge flows, improved temperature management, and extended component life by allowing two independent cooling circuits within a single rotating component, simplifying construction and maintaining turbomachine operability.
Implementation Method 1
A first plurality of purge circuits are formed in the body and are arranged to direct a first purge flow in a first direction
Implementation Method 2
the purge air flow reduces temperature gradients as well as lowers peak rotor wheel temperature
Implementation Method 3
A second plurality of purge circuits are also formed in the body and are arranged to direct a second purge flow in a second direction, that is distinct from the first direction
Implementation Method 4
the purge air flow reduces temperature gradients as well as lowers peak rotor wheel temperature
Implementation Method 5
the purge air flow reduces temperature gradients as well as lowers peak rotor wheel temperature to enhance component life and turbomachine operability
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A wheel member (20, 21, 22) includes a body (50) having a first surface (54) that extends to a second surface (55) through an intermediate portion (56). The body (50) includes an outer diametric surface (58) and a central bore (60). A first plurality of purge circuits (64) are formed in the body (50). The first plurality of purge circuits (64) extend from a first end (74) to a second end (75) through the body (50). The first plurality of purge circuits (64) are arranged to direct a first purge flow (80) in a first direction. A second plurality of purge circuits (68) are formed in the body (50) and fluidly isolated from the first plurality of purge circuits (64). The second plurality of purge circuits (68) extend from a first end portion (85) to a second end portion (86) through the body (50) and are arranged to direct a second purge flow (95) in a second direction, that is distinct from the first direction, to establish a cross-over purge flow system (45).