Bleed Air Heat Exchanger Cooling for Hybrid Engine Tail Cone Electronics

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Solution Overview

Problem

Future hybrid engine programs require a ventilation system to maintain low thermal capability electronics in the tail cone zone, as existing systems are inadequate for managing excess thermal energy generated by these components.

Innovation Solution

An environmental control system utilizing bleed air from a bleed air system, a heat exchanger, and ambient cooling air to manage thermal energy, with features like a pylon-mounted heat exchanger, shutoff valve, and air scoops to enhance cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If existing ventilation systems are used, then the system structure is simple, but the thermal energy removal capability is insufficient for electronics in the tail cone zone

Engineering Contradiction:
Improvethermal energy removal capabilityVSAvoidsystem structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines the environmental control system bleed air system with a dedicated cooling system for electronics. The bleed air system, originally designed for environmental control, is integrated to also provide cooling functionality by routing cooled bleed air to electronics in the tail cone zone, merging two functions into one system

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a heat exchanger as an intermediary component between the bleed air system and the electronics. The heat exchanger transfers thermal energy from the bleed air to the surrounding structure or ambient air, enabling indirect cooling of electronics without direct contact between cooling media and electronic components

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If bleed air is used for cooling electronics, then the cooling effectiveness is improved, but the system complexity increases due to additional components and routing

Engineering Contradiction:
Improvecooling effectivenessVSAvoidcomponents and routing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bleed air system is designed to serve multiple functions: environmental control for the aircraft cabin and cooling for electronics in the tail cone zone. By making the bleed air system universal, the patent eliminates the need for separate cooling systems, reducing overall complexity while maintaining cooling effectiveness

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

Solution Approach 2:

The cooling system is segmented into distinct functional zones: the bleed air source, the heat exchanger section, and the distribution lines to electronics. This segmentation allows each component to be optimized independently while maintaining overall system reliability and ease of maintenance

Inventive Principle:
Principle #1Segmentation

3Temperature

If a heat exchanger is installed in the pylon structure, then the cooling capacity is enhanced, but the installation complexity and structural modifications increase

Engineering Contradiction:
Improvecooling capacityVSAvoidinstallation complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The heat exchanger is installed in the pylon structure, utilizing the vertical and lateral dimensions of the engine support structure. This three-dimensional integration allows the heat exchanger to be positioned in available structural space without requiring additional external installations, enhancing cooling capacity while minimizing impact on manufacturing

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If ambient cooling air is used to remove thermal energy, then the cooling efficiency is improved, but the system requires additional air inlet and outlet pathways

Engineering Contradiction:
Improvecooling efficiencyVSAvoidair pathways
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system utilizes ambient cooling air that flows naturally through the aircraft structure and heat exchanger. The design leverages the aircraft's own airflow patterns and pressure differentials during flight to provide cooling, making the system self-service and eliminating the need for additional active air moving components or complex controlled pathways

Inventive Principle:
Principle #25Self-service

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 maintains operational temperatures within limits, providing dedicated cooling to electronics and engine components, even under off-normal conditions, using a scoop-enhanced design with enhanced pressure differentials.

Implementation Method 1

a heat exchanger fluidly coupled between the bleed air system and a gas turbine engine; and ambient cooling air fluidly coupled with the heat exchanger, wherein the ambient cooling air is configured to remove thermal energy from the bleed air flowing through the heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4686815A1High pressure cooling systems for hybrid and conventional engines
Publication Date: 2026.02.04 RTX CORP
  • EP4686815A1 patent drawingFigure 1
  • EP4686815A1 patent drawingFigure 2~3
  • EP4686815A1 patent drawing

AI summary

An environmental control system bleed cooling system including bleed air from the environmental control system bleed air system; a heat exchanger fluidly coupled between the environmental control system bleed air system and a gas turbine engine; and ambient cooling air fluidly coupled with the heat exchanger, wherein the ambient cooling air is configured to remove thermal energy from the bleed air flowing through the heat exchanger.