SMA Heat Engine Pulley System for Waste Thermal Energy Recovery
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Solution Overview
Problem
Waste thermal energy generated by industrial, automotive, and manufacturing processes is often dissipated without being harnessed for useful purposes, representing a significant inefficiency in energy utilization.
Innovation Solution
A heat engine utilizing a shape-memory alloy (SMA) element that converts thermal energy gradients into mechanical energy by selectively changing crystallographic phase between martensite and austenite, thereby rotating pulleys and generating mechanical energy, which can be further converted into electrical energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If shape memory alloy elements are used to convert thermal energy to mechanical energy, then energy utilization efficiency is improved, but device complexity increases
Solution Approach 1:
The patent utilizes the phase transition properties of shape memory alloy (SMA) elements between austenite and martensite phases to convert thermal energy into mechanical work. The SMA elements undergo reversible phase changes in response to temperature variations, enabling the heat engine to operate without moving mechanical valves or complex piston mechanisms, thus reducing overall device complexity while improving energy utilization.
Solution Approach 2:
The invention replaces traditional mechanical components (pistons, valves, connecting rods) with SMA elements that directly convert thermal energy to mechanical motion through phase transitions. This substitution eliminates complex mechanical linkages and reduces the number of moving parts, thereby reducing device complexity while maintaining energy conversion functionality.
2Power
If SMA elements are placed at different radial distances on pulleys, then mechanical energy output is improved, but manufacturing precision requirements increase
Solution Approach 1:
The timing cable serves multiple functions: it synchronizes the rotation of pulleys, transmits mechanical power, and compensates for variations in SMA element positioning. By using a single component (timing cable) to handle multiple tasks, the system can tolerate greater variations in SMA element placement without compromising overall performance, thus reducing manufacturing precision requirements while maintaining power output.
Solution Approach 2:
The timing cable acts as an intermediary element between the SMA elements and the load. It provides mechanical coupling and synchronization while accommodating tolerances in SMA element positioning. The timing cable's flexibility and tensioning mechanism allow it to absorb positioning variations, enabling the system to achieve desired power output without requiring extremely precise manufacturing of SMA element locations.
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 SMA-based heat engine effectively captures and converts waste thermal energy into usable mechanical and electrical energy, enhancing energy efficiency and reducing waste heat dissipation.
Implementation Method 1
The SMA element selectively changes crystallographic phase between martensite and austenite and thereby either contracts and expands in response to exposure to the first temperature and the second temperature
Implementation Method 2
The SMA element selectively changes crystallographic phase between martensite and austenite
Implementation Method 3
A first rotatable pulley and a second rotatable pulley spaced from the first rotatable pulley. The SMA element is disposed about a portion of the first rotatable pulley at a first radial distance and about a portion of the second rotatable pulley at a second radial distance
Data Source
AI summary
A heat engine includes a first rotatable pulley and a second rotatable pulley spaced from the first rotatable pulley. A shape memory alloy (SMA) element is disposed about respective portions of the pulleys at an SMA pulley ratio. The SMA element includes a first wire, a second wire, and a matrix joining the first wire and the second wire. The first wire and the second wire are in contact with the pulleys, but the matrix is not in contact with the pulleys. A timing cable is disposed about respective portions of the pulleys at a timing pulley ratio, which is different than the SMA pulley ratio. The SMA element converts a thermal energy gradient between the hot region and the cold region into mechanical energy.