Toroidal Multi-Stage Thermoacoustic Engine Layout for Compact Power Gain
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Solution Overview
Problem
Existing multi-stage thermoacoustic heat engines are thermally and mechanically cumbersome, volumetrically inefficient, and prone to high thermal stresses due to the repeated exposure of the gaseous working fluid's acoustic power path to common thermal interfaces, limiting their scalability and efficiency.
Innovation Solution
A multi-stage traveling wave thermoacoustic engine with a topologically folded acoustic power path that re- accesses the same thermal interfaces multiple times within a single domed pressure vessel, minimizing hot joints and improving manufacturing simplicity and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple heat engine stages are connected in series with common thermal interfaces, then the overall gain of the engine is increased, but the device becomes thermally and mechanically cumbersome with high thermal stresses
Solution Approach 1:
The engine is divided into multiple discrete stages (first stage with first hot/cold heat exchangers, second stage with second hot/cold heat exchangers, etc.), where each stage operates independently with its own thermal interfaces. This segmentation allows the acoustic power to be processed through multiple stages without subjecting a common thermal interface to repeated exposure, thereby reducing thermal and mechanical complexity while maintaining increased overall gain.
2Power
If a folded loop topology is used to provide common thermal interface points, then multi-stage operation is achieved, but the device becomes very large and volumetrically inefficient
Solution Approach 1:
The patent transitions from a planar folded loop topology to a three-dimensional stacked configuration where stages are arranged vertically one above another. Each stage occupies a separate vertical level within the pressure vessel, allowing multiple stages to coexist in a compact volume without requiring the extensive horizontal spacing needed for folded loop topologies.
3Reliability
If stages are physically separated, then thermal stress is reduced, but volumetric efficiency and scalability are compromised
Solution Approach 1:
The patent employs a nested arrangement where multiple stages are stacked concentrically within the pressure vessel, with each stage containing its own thermal interfaces and acoustic processing components. This nesting allows stages to be physically separated for thermal stress reduction while maintaining compact volumetric efficiency through hierarchical spatial organization.
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 enhances volumetric and thermal efficiency, improves scalability, and reduces thermal stresses, resulting in a more efficient and reliable power generation system.
Implementation Method 1
Thermal buffer tube 112 provides a thermal buffer between hot heat exchanger 110 and the cold side (114 and 116) by providing space for the heated helium gas to oscillate without reaching the cold side
Implementation Method 2
A flow straightener and heat exchanger 114 suppress prevent certain types of gas flow and reduces heat loss thereby improving the thermal efficiency of the heat engine
Implementation Method 3
Jet pump 120 is used to reduce gas streaming and thereby improve thermal efficiency
Implementation Method 4
Applying heat at one end of the tube creates a heat differential along the length of the tube and induces sound waves which can be used to convert the heat into mechanical energy
Data Source
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AI summary
A multi-stage traveling wave thermoacoustic engine is disclosed. A plurality of heat engine stages are formed as a toroidal spiral cascade of N stages inside a pressure vessel. Each stage feeds into the next stage such that all of the thermoacoustic power cycles past a common set of thermal interfaces multiple times with the single domed pressure vessel. The inventive thermoacoustic engine is simpler and cheaper to manufacture and more reliable due to the minimization of hot joints.