Tail Cone Cooling Ducts for Turbine-Mounted Electrical Apparatus

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cooling systems for electrical apparatus in aircraft gas turbine engines, particularly those installed behind the low-pressure turbine, face complexity and inefficiency due to the need for custom designs to manage heat from hot exhaust gases, which complicates the cooling process.

Innovation Solution

A cooling system that incorporates a primary duct and secondary duct configuration, where the primary duct connects the outlet passage of the low-pressure compressor to the housing via a strut, and the secondary duct connects the bypass passage to the housing, both with shielding structures to prevent heat ingress and facilitate cooling gas flow, allowing for effective cooling of electrical apparatus with a simpler configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an oil cooling system is used to cool electrical apparatus behind the turbine, then the electrical apparatus can be cooled, but the system structure becomes complicated and requires custom design according to the object shape

Engineering Contradiction:
Improvecooling effectivenessVSAvoidcooling system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the traditional oil cooling system with an air cooling system. The air cooling system uses cooling air passages formed within the housing structure itself, eliminating the need for complex oil channels, pumps, and heat exchangers. The housing incorporates internal cooling air passages that directly channel cooling air to the electrical apparatus, simplifying the overall system structure while maintaining effective cooling.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The housing serves multiple functions: it provides structural support, contains the electrical apparatus, and acts as a cooling system through its integrated cooling air passages. This multi-functionality eliminates the need for separate dedicated cooling components, reducing system complexity while maintaining cooling effectiveness.

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

2Productivity

If the electrical apparatus is installed behind the low-pressure turbine, then power generation efficiency is improved, but the apparatus is exposed to hot exhaust gases causing thermal damage risks

Engineering Contradiction:
Improvepower generation efficiencyVSAvoidthermal damage from exhaust gases
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The housing acts as an intermediary barrier between the hot exhaust gases and the electrical apparatus. It incorporates cooling air passages that channel cooler air from the compressor outlet through the housing structure to the electrical apparatus, creating a thermal buffer zone that protects the apparatus from direct exposure to hot exhaust gases while allowing the apparatus to remain in the optimal position for power generation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the temperature difference between the hot exhaust gases and the cooler compressor outlet air into a beneficial cooling mechanism. The housing structure utilizes this temperature gradient by channeling the cooler air through internal passages to cool the electrical apparatus, effectively using the thermal environment to protect the apparatus rather than harm it.

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

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 efficient cooling of electrical apparatus behind the turbine with a simpler setup, reducing thermal damage risks and improving reliability by using air cooling, which can be used alone or in combination with oil cooling systems.

Implementation Method 1

A cooling system that incorporates a primary duct and secondary duct configuration, where the primary duct connects the outlet passage of the low-pressure compressor to the housing via a strut, and the secondary duct connects the bypass passage to the housing, both with shielding structures to prevent heat ingress and facilitate cooling gas flow

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

both with shielding structures to prevent heat ingress

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Data Source

PatentEP3926157B1Cooling system for aircraft gas turbine engine
Publication Date: 2024.05.15 IHI CORP
  • EP3926157B1 patent drawingFigure 1
  • EP3926157B1 patent drawingFigure 2
  • EP3926157B1 patent drawingFigure 3

AI summary

A cooling system includes: a core casing (18) configured to house a compressor (12, 13), a combustion chamber (14), and a turbine (15, 16); a tail cone (28) configured to form at least part of an exhaust passage (23) of the turbine (15, 16) together with the core casing (18); struts (27) configured to connect the core casing (18) with a support body (26) of the tail cone (28); a housing (31) installed in the tail cone (28), configured to house an electrical apparatus; and at least one primary duct (40) configured to connect between an internal space of the housing (31) and an outlet passage (12a) of the compressor (12) or a discharge port of a blower (34) installed in a gas turbine engine via at least one of the struts (27) and a radial outside of the core casing (18).