Nested Exhaust Heat Exchanger for Aircraft Turbine Energy Recuperation
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Solution Overview
Problem
Turbine engines lose energy due to the exhaustion of high-temperature gases, and existing technologies do not effectively recuperate this energy to improve engine performance.
Innovation Solution
An aircraft propulsion system that includes a turbine engine and an exhaust gas heat exchanger, which extends axially and features a central conduit, outer radial plenum, fluid conduits, and inter-conduit passages, allowing for a serpentine fluid flow path to recuperate energy from exhaust gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a simple exhaust system is used, then the device complexity is low, but energy is lost without effective recuperation
Solution Approach 1:
The heat exchanger employs a nested arrangement of multiple fluid conduits (first, second, third fluid conduits) where each conduit is positioned within or adjacent to others, creating a compact concentric structure. This nesting allows multiple fluid streams to be processed simultaneously within a confined space, maximizing heat recuperation while minimizing the overall device footprint and complexity
Solution Approach 2:
The invention transitions from a single-dimensional exhaust flow to a multi-dimensional heat exchange system by arranging fluid conduits in concentric circles around the central exhaust passage. This radial arrangement in the cross-sectional plane creates multiple heat exchange surfaces simultaneously, enabling comprehensive energy recuperation without significantly increasing axial length or overall complexity
2Productivity
If multiple fluid conduits are added to increase heat exchange efficiency, then energy recuperation improves, but the device complexity increases
Solution Approach 1:
The invention combines multiple heat exchange functions into a single integrated heat exchanger assembly. The first, second, and third fluid conduits are merged into a concentric arrangement around the central exhaust passage, with inter-conduit passages providing fluid communication between them. This merging allows multiple fluid streams to exchange heat simultaneously within one compact structure, achieving high energy recuperation efficiency without proportionally increasing device complexity
Solution Approach 2:
The heat exchanger assembly serves multiple functions simultaneously: the central exhaust passage handles exhaust gas flow, while the nested fluid conduits handle multiple working fluids at different stages of the Brayton cycle. The inter-conduit passages provide both structural support and fluid communication pathways. This multi-functionality maximizes energy recuperation while minimizing the number of separate components needed
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 recuperates energy from exhaust gases, improving the performance of the turbine engine and enhancing the Brayton cycle efficiency.
Implementation Method 1
The exhaust gas heat exchanger includes a central conduit, an outer radial plenum, a plurality of fluid conduits, and a plurality of inter-conduit passages... pass through the exhaust gas passages disposed between adjacent fluid conduits
Implementation Method 2
A serpentine fluid flow path extends through the fluid conduits and the inter-conduit passages... exhaust gases from the turbine engine enter the forward end of the exhaust gas heat exchanger, pass through the exhaust gas passages
Data Source
AI summary
An aircraft propulsion system is provided that includes a turbine engine and an exhaust gas heat exchanger. The exhaust gas heat exchanger includes a central conduit, an outer radial plenum, fluid conduits, and inter-conduit passages. The fluid conduits are disposed in a nested arrangement. Each fluid conduit has inner and outer radial walls that extend axially between the forward and aft ends. The inner and outer radial walls are radially separated to form an internal fluid passage. Each fluid conduit is radially spaced apart from adjacent fluid conduits to define an axially extending exhaust gas passages. The inter-conduit passages include at least one inter-conduit passage that provides fluid communication between the central conduit and a first fluid conduit, and at least one inter-conduit passage that provides fluid communication between first and second fluid conduits. A serpentine fluid flow path extends through the fluid conduits and the inter-conduit passages.