Spiraled Heat Exchange Passage for Fuel-Based Powerplant Cooling

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Solution Overview

Problem

Existing gas turbine engines face challenges in efficiently cooling internal components due to the inefficiency of bleeding compressed air for cooling, which also complicates the inclusion of internal passages for routing bleed air, especially as engines become more compact.

Innovation Solution

A powerplant assembly incorporating a heat exchange passage that spirals around key components like the electric machine and bearings, utilizing a fuel source to fluidly couple with the heat exchange passage for cooling and lubrication, thereby transferring heat energy from these components into a flowing fluid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If bleed air is used for cooling internal components, then cooling effectiveness is improved, but engine efficiency deteriorates

Engineering Contradiction:
Improvecooling effectivenessVSAvoidengine efficiency
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent converts the harmful hot exhaust gases into a beneficial cooling resource by routing them through heat exchange passages that spiral around internal components like the electric machine and bearings. This transforms waste heat into useful cooling effect, eliminating the need to bleed compressed air and thereby preserving engine efficiency while achieving effective cooling

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Temperature

If internal passages for routing bleed air are added, then cooling capability is improved, but device complexity increases

Engineering Contradiction:
Improvecooling capabilityVSAvoidinternal passage complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The heat exchange passages serve multiple functions simultaneously: they cool internal components by transferring heat from hot exhaust gases, provides structural support as part of the engine housing, and enable heat recovery for preheating intake air or other utility purposes. This multi-functionality reduces the need for dedicated separate cooling passages, thereby simplifying overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The heat exchange passages are designed with spiral or curved geometries that follow the contours of internal components like the electric machine and bearings. This curved path arrangement allows the passages to wrap around components efficiently within the compact engine space, providing comprehensive cooling coverage without requiring complex straight-line routing or multiple discrete passage segments

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Volume of moving object

If engine size is reduced for compactness, then space utilization is improved, but routing of cooling passages becomes more difficult

Engineering Contradiction:
Improveengine sizeVSAvoidpassage routing difficulty
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The spiral and curved heat exchange passages are specifically designed to navigate the compact engine geometry by wrapping around the electric machine and bearings in a space-efficient manner. This curved routing allows the passages to make optimal use of the limited radial and axial space available in the compact engine layout, providing effective cooling without requiring additional engine volume

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The heat exchange passages are nested within the existing engine structure by routing them through the walls and supports of the engine housing, and by positioning them in concentric arrangements around rotating components. This nesting approach allows the cooling system to be integrated within the compact engine envelope without adding external bulk or requiring separate dedicated cooling zones

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Effectively cools and lubricates critical components while maintaining engine efficiency by utilizing a spiraling heat exchange passage that uses fuel to dissipate heat, reducing the need for bleed air and simplifying internal cooling systems.

Implementation Method 1

transferring heat energy from these components into a flowing fluid

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

heat exchange passage that spirals around key components like the electric machine and bearings, utilizing a fuel source to fluidly couple with the heat exchange passage for cooling

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

utilizing a fuel source to fluidly couple with the heat exchange passage for cooling and lubrication, thereby transferring heat energy from these components into a flowing fluid

Methodology Applied
Scientific EffectThermal energy dissipation: Heat Exchanger

Data Source

PatentEP4636226A1Powerplant with spiraled heat exchange passage
Publication Date: 2025.10.22 RTX CORP
  • EP4636226A1 patent drawingFigure 1
  • EP4636226A1 patent drawingFigure 2
  • EP4636226A1 patent drawingFigure 3

AI summary

An assembly is provided for a powerplant (20). This powerplant assembly includes an electric machine (24), a stationary structure (70) and a fuel source (96). The electric machine (24) includes an electric machine rotor (82). The electric machine rotor (82) is configured to rotate about an axis (26). The stationary structure (70) supports the electric machine (24) and includes a heat exchange passage (92). The heat exchange passage (92) spirals around the electric machine (24) as the heat exchange passage (92) extends within the stationary structure (70) and axially along the electric machine (24). The fuel source (96) is fluidly coupled to the heat exchange passage (92).