Nitinol thermodynamic state surfaces

Journal Article · Fri Sep 01 04:00:00 EDT 1978 · J. Energy; (United States)

OSTI ID:6780066

Cory, J S

Joule effect heat engines, using the shape memory alloy Nitinol as the working material, offer a realistic potential of converting cheap and abundant low-temperature heat energy into shaft power, much more efficiently and cheaply than conventional heat engines. Reasonable performance limits for commercial engines are expected to be 80% of Carnot, if optimized for efficiency, or $50 per kilowatt, if optimized for cost. These estimates are based on clearly perceived thermodynamic cycle improvements of experimental Nitinol heat engines that have already achieved a measured performance of about 1/5 of these limits. Once this potential is converted into commercial reality by the development of a Nitinol heat engine technology, a major tool for solving the world energy problem will become available. The engineering thermodynamics of Nitinol is one of the key elements of this technology. As shown by 150 years of heat engine experience, thermodynamics is vital for the efficient development of the technologies of system studies, invention, optimization, detailed design, and test evaluation of heat engine. To fulfill this role for Nitinol heat engines, historical experience shows that the engineering thermodynamics of Nitinol must (1) specify the necessary and sufficient state variables, (2) provide a quantitative description of all possible thermodynamic paths, together with (3) the work, (4) the heat flow, and (5) the energy dissipation associated with each of these paths. The purpose of this paper is to present an empirical data correlation which furnishes the first three requirements. A report is in preparation which provides a quantitative description of the heat flow and energy dissipation.

• Research Organization: Cory Labs., Inc., Escondido, CA
• OSTI ID: 6780066
• Journal Information: J. Energy; (United States), Journal Name: J. Energy; (United States) Vol. 2:5; ISSN JENED
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140909 -- Solar Thermal Utilization-- Miscellaneous Solar Applications-- (1980-)
36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
42 ENGINEERING
425007* -- Engineering-- Power Cycles-- Other-- (1980-)
ALLOYS
CARNOT CYCLE
COMMERCIALIZATION
CONVERSION
COST
EFFICIENCY
ENERGY CONVERSION
ENGINES
ENTROPY
EVALUATION
HEAT ENGINES
HYSTERESIS
NICKEL ALLOYS
NITINOL
NITINOL HEAT ENGINES
PHYSICAL PROPERTIES
SOLAR HEAT ENGINES
SURFACE PROPERTIES
THERMODYNAMIC CYCLES
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
TITANIUM ALLOYS