The efficiency and power of the martensite rotor heat engine. I

TL;DR

This paper analyzes the thermodynamic and mechanical aspects of the martensite rotor heat engine (MRHE), deriving formulas for efficiency and power, and explores its potential for eco-friendly electricity generation using low-potential water sources.

Contribution

It provides analytical expressions for MRHE efficiency and power, considering material properties and hydraulic resistance, and evaluates its application potential with numerical estimates for nitinol.

Findings

Maximum power depends on engine parameters and material properties.

Optimal engine parameters enhance efficiency and power output.

MRHE can be effectively used for eco-friendly electricity generation.

Abstract

The physical aspects - mechanics and thermodynamics - of operation of martensite rotor heat engine (MRHE) on the basis of martensite-austenite structural phase transition with the transition temperature in the region of low-potential water temperatures have been studied. The engine converts the thermal energy of low-potential water into the elastic energy of working body (spring, ribbon or wire) made of the material with shape memory effect. At some simplifying assumptions, the analytical expressions are obtained for the thermal efficiency and the power of MRHE of different type. The registration of head hydraulic resistance and heat conductivity of working body material is made and the maximum value of power produced by the engine at the given mechanical and heat conditions is calculated. The recommendations are given on the optimal choice of engine parameters. On the basis of numerical estimations for nitinol, the possibility of application of MRHE is shown for efficient and ecologically pure production of electric energy both on local (geothermal waters, waste water of industrial enterprises, etc.) and global (warm ocean stream) scales.