Banks, an independent machinist and inventor in point richmond, california, develops novel heat engines using a peculiar alloy called nitinol. Pdf shape memory effect and performance of a nitinol engine. Nitinol is a trade name taken from the elements its composed ofnickel ni and titanium tiand the scientific group that discovered itthe naval ordnance laboratory nol. Most existing heat engines use methods of actuation that are subject to significant frictional losses. Thermophysical properties of 60 nitinol for mechanical component applications malcolm k. Nitinol metal alloy is one of the most useful alloys used for various purposes. Simply immerse the leading edge of the smaller pulley into an 45 90 degree celsius water bath, give the larger wheel a gentle spin and. The nitinol heat engine nhe uses a shapememory alloy of nickel and titanium to convert thermal energy directly to mechanical power and through a generator, to electricity. Memry offers nitinol in sheet form to broaden opportunities for designers working with nitinol. What temperature difference is required for a nitinol heat.
Ive heard about it quite a few times, people used to say me that it looked and worked like a perpetual machine. Nitinol wires are used in model heat engines made for demonstration purposes. Dec 22, 2016 the video is interesting and i vaguely remember reading something about this back in the 1970s from my popular science magazines. Nitinol shape memory alloys can be modified to a great extent by changes in composition, mechanical working, and heat treatment. Nitinol with shape memory could be easily deformed under the activation temperature.
Chapter ix energy conversion with heat engines background the basic resource of solar energy is a constant temperature thermal source at approximately 10,000 f. Exergia memory metal engine learning kit hs200 this is a very special kind of heat engine that demonstrates the conversion of heat into mechanical energy. Pdf the efficiency and power of the martensite rotor. Mar 10, 2016 the proceedings of the nitinol heat engine conference. Solar hot water nitinol heat engines packrat workshop. Working with a flat substrate enables rapid production of small components nested within a sheet or the ability to create large and unique structures that are not possible when starting with wire or tubing.
Oxidation of nitinol and its effect on corrosion resistance. It uses the unique property of nitinol alloy 50% nickel, 50% titanium, the nol at the end of nitinol refers to naval ordnance laboratory in. Despite the united states navy declaring to the department of energy that the development of nitinol heat engines would clearly serve the national interests by helping reduce petroleum energy dependence, this technology was swept under the rug. Heat engines a heat engine is any closedcycle device that extracts heat from a hot reservoir, does useful work, and exhausts heat to a cold reservoir. The present invention is a heat engine utilizing thermally responsive elements of a shape memory material. 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. Nickel titanium, also known as nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages.
Proceedings of the nitinol heat engine conference pdf download. Among the materials used for this purpose, the alloys with shape memory effect, especially nitinol alloy. Shape memory alloys the term alloy describes a solid structure that is composed of two or more elements. A team from the nol discovered the alloy while searching for materials that could be. The thermodynamics of nitinol heat engines was examined from the viewpoints of both theory and application. Nitinol wire shape memory nickel titanium alloy wire. If you heat it, it tries to return to the shape it remembers. Nitinol powered motor x 1 cold water bucket x 1 hot water bucket x 1 be the first to see a really practical clean safe energy source. All this, allows the nitinol engines to operate on heat energy of lowpotential lp waters, among which are the geothermal waters, waste waters of industrial. More specifically, it is a simple single wire nitinol engine using the basic principle of my prior u. It uses the unique property of nitinol alloy 50% nickel, 50% titanium, the nol at the end of nitinol refers to naval ordnance laboratory in maryland usa where this alloy has been developed called the memory effect. Aug 18, 2008 the engine efficiency in terms of the energy loss due to friction and the heat. On the visible level, superelastic nitinol is very springyyou would have a very hard time putting a kink in it.
It is seen that higher thermal efficiency can be obtained if a nitinol alloy with a larger h value than given above can be found. The thermodynamic system analyzed is a nitinol helix for which extensive forcelengthtemperature flt equation of state measurements have been made. Nitinol in the cold work condition as drawn or as rolled is material that has not been subject to a final heat treatment shape set anneal. Okay, let me firstly mention you that i had no idea about nitinol heat engine. Therefore i dont have to specifically stress out all the patents and designs for the heat engines that have already been tried and developed. And after digging and researching a loads of informati. Nitinol heat engines ridgway banks lawrence berkeley. In the heat device, the nitinol loop wire has the property of. Review critical overview of nitinol surfaces and their modi. The use of nitinol tubing for various medical purposes is increasing in popularity.
The nitinol heat engine of claim 8 wherein the counterweighted crank means provides a semicircular motion to the lower ends of said levers to effect submerging the nitinol wires in a first temperature bath and then reversing direction to move the wires in a partially circular arc up and out of the first temperature bath and over and down into. All prototypes can be found in the paper called proceedings of nitinol heat engine conference 1978. The vt1 shape memory alloy heat engine design city tech. The device applies only hot water hot side and cold ambient air cool side. This video explores how a basic nitinol heat engine works. The heat engine is a very special kind of heat engine that demonstrates the conversion of heat energy into mechanical energy. Abandoned application number us14476,878 inventor joseph lawrence kellogg mingming guo. Nickel titanium, also known as nitinol part of shape memory alloy, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages e. It has been shown that nitinol corrosion resistance can be significantly improved by surface treatments such as electropolishing 1. The nitinol heat engine, discussed in this thesis, is also a result of this growing interest in the quest for alternative power sources. It is a nickel titanium metal alloy with some unique properties.
Nitinol nickel titanium properties, uses and composition. This paper examines three separate technologies for ac. Whatever happened to nitinol based heat scavenging power. Heat engine nitinol metal engine driven by hot and cold water. The heatmobile is a very special kind of heat engine that demonstrates the conversion of heat into mechanical energy.
Alfred johnson who was granted a patent on this type of heat engine in 1977 patent. Engine performance data and new designs up to 25 hp were presented during the sessions. This paper mainly focuses on the parameters that affect power output of nitinol heat engine and phase transforma tion char acteristics of nitinol wir e. The difference between superelastic and shape memory nitinol is pretty basic, but it throws a lot of people off. Feb 07, 2018 this is a follow up to a previous video. Whereas shape memory nitinol can be bent at low temperatures and then heated to be restored to the original shape. The pulleys feature ball bearing construction for fluid movement. Diy nitinol engine questions energy forum at permies.
The inventor of the present invention is also the inventor of the banks nitinol heat engines, u. This video features the final working version of the previous design. It exhibits the shape memory effect and superelasticity at different temperatures nitinol alloys exhibit two closely related and unique. In the 30% coldworked wire, however, the rphase is only observed after heat. Stanford national aeronautics and space administration glenn research center cleveland, ohio 445 abstract the linear thermal expansion coefficient, specific heat capacity, electrical resistivity and thermal conductivity of 60. Unlike conventional heat engines such as gasoline or other fuel type engines, nitinol heat engines do not require high combustion temperatures. Introduction the problem of creation of heat engines operating on the basis of structural phase transitions in solids has been of special interest for researchers during several tens of years. Nitinol wire description nitinol is a nickeltitanium alloy with super elasticity and shape memory properties.
Shape memory alloys smas are unique alloys in that they can remember an original shape after being deformed. Tests on nitinol wire in simulations of various heat engine cycles are reported on, as well as the training bistable memory phenomenon. Nitinol wires can be used for marking and locating breast tumors. Nitinol is a shape shifting memory alloy, that can be used to produce mechanical energy, by. An nhe was analyzed and designed to produce power from solar irradiation in space, with radiative cooling to a deepspace heat. Let us consider this process similar to heat transfer of metal su rface at the. In sheet and strip products, that value is usually closer to 20% reduction. It uses the unique property of nitinol alloy to generate mechanical motion from heat. The wheel of the heating device is immersed in a hot liquid 5.
Transformation strain for polycrystalline material for a. Nitinol memory metal heat engine nitinol wire stirling. Van humbeecka akatholieke universiteit leuven, mtm kasteelpark arenberg 44, b3001 leuven, belgium bames laboratory, ames, ia 50011, usa received 18 july 2007. The nitinol system exhibits significant hysteresis and is determined. Well, not not far from the laboratory, apparently, and almost certainly very specialized, niche. This allows the design of devices that apply a constant force or load stress over a wide range of shapes. Electropolishing of nitinol forms a protective uniform titanium oxide layer that protects the base material from corrosion.
The field that pertains to the present invention is that of heat engines, more particularly, a nitinol powered heat engine which produces a linear output for the purpose of doing work. The heat engineis a very special kind of heat engine that demonstrates the conversion of heat energy into mechanical energy. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. If this resource isto be used for anything other than lighting, the energy received must be converted into a more useful form. Longer heat treatments result in a typical twostage transformation. Unitek nitinol heat activated wire is available in the following configurations. Extraodinary energy devices heat, evaporation, electricity.
The video is interesting and i vaguely remember reading something about this back in the 1970s from my popular science magazines. The first nitinol motor was built and studied in the 1970s, nearly 40 years ago. It behaves almost like a tin wire with one difference it cant be bend to too acute angles. Nitinol heat engine uses the unique property of nitinol alloy to generate mechanical motion from heat. The idea of a heat engine that employs a shapememoryalloy sma as the mediator, through which heat flow transforms into kinetic energy is probably a few minutes younger than that of the sma alone. Full text views reflects the number of pdf downloads, processing of small scale nitinol billets by induction heated nonconventional isothermal extrusion. Nov 23, 2012 thermophysical properties of 60 nitinol for mechanical component applications malcolm k. Efficiency of the solidstate engine made with nitinol memory material. May 29, 1984 the present invention relates to heat engines and more particularly to a single wire nitinol powered heat engine. Alfred johnson who was granted a patent on this type of heat engine.
A closedcycle device is one that periodically returns to its initial conditions, repeating the same process over. Different alloys are named according to the weight percentage of nickel, e. This simple nitinol wire heat engine is constructed of a boomerang shaped clear acrylic holder with two high quality cast aluminum pulleys. Nitinol heat engine with mechanical storage mechanism. This alloy exhibits the superelasticity or pseudoelasticity and the shape memory properties. The heat device uses a loop of nitinol wire to generate power. Nitinol is a shape shifting memory metal alloy that can produce mechanical energy by simple temperature variation. Nitinol engine is f ed by the heat energy of lp water by means of heat transfer at the boundary of wire lp water. Nitinol heat motor for sale energy forum at permies. Schiller thesis submitted to the faculty of virginia polytechnic institute and state university in partial fulfillment of the requirements for a degree of master of science in mechanical engineering dr. Latheman666 recently posted a video see below of a nitinol engine that uses a temperat. The present invention relates to heat engines and more particularly to a single wire nitinol powered heat engine. He has taught junior high school music and science, published chamber music, and worked as a technical associate for lawrence berkeley laboratory.
Nitinol version of a minto wheel type and teetertotter engine this is an attempt to get away from expensive and dangerous gases. Surveys indicate that a high percentage of all mechanical components value, manufactured in the world, comes from machining operations and that annual expenditure on machine tools and cutting. Proceedings of the nitinol heat engine conference, 2627. Us20160069331a1 nitinol heat engine with mechanical storage. It operates somewhat the same as a regular minto wheel but instead of using a low boiling point liquid to provide the pumping action it uses a set of nitinol springs. An nhe was analyzed and designed to produce power from solar irradiation in space, with radiative cooling to a deepspace heat sink. Shape memory refers to the ability of nitinol to undergo deformation at one temperature, then recover its original, under formed shape upon heating above its transformation temperature.
The dsc test yields extremely repeatable curves where tangents are used to identify the start, finish and peak temperatures of each of. It is now understood that nitinol stabilizes, under certain conditions, so that a stressstraintemperature cycle may be repeated indefinitely. This fully assembled memory metal heat engine demonstrates the conversion of heat energy into mechanical energy. Shape memory alloys have the remarkable property of being easily deformed at low temperatures, but rapidly and. Proceedings of the nitinol heat engine conference, 26. Jun 09, 2016 nitinol is a kind of wire that has a memory. Thermophysical properties of 60nitinol for mechanical. The engine in his video is said to be running at 70 rpm for over 23,000,000 revolutions. Unlike other heat engines, the vt1 heat engine induces actuation using. Perhaps a nitinol motor could use waste heat in a hybrid vehicles engine to charge the battery for higher efficiency, or replace the alternator on regular vehicles. The efficiency and power of the martensite rotor heat engine.
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