Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
  • F03G7/00—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for
  • F03G7/06—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like
  • F03G7/061—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like characterised by the actuating element
  • F03G7/0614—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like characterised by the actuating element using shape memory elements
  • F03G7/06143—Wires
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
  • F03G7/00—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for
  • F03G7/06—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like
  • F03G7/064—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like characterised by its use
  • F03G7/0641—Motors; Energy harvesting or waste energy recovery
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
  • F03G7/00—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for
  • F03G7/06—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like
  • F03G7/061—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like characterised by the actuating element
  • F03G7/06114—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like characterised by the actuating element using the thermal expansion or contraction of solid materials
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
  • F03G7/00—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for
  • F03G7/06—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like
  • F03G7/061—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like characterised by the actuating element
  • F03G7/0612—Mechanical-power-producing mechanisms, not otherwise provided for or using energy sources not otherwise provided for using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like characterised by the actuating element using polymers

Definitions

• the present application relates to the field of energy recovery and in particular to the use of Shape-Memory Alloys (SMAs) or Negative Thermal Expansion materials (NTE) for the same.
• SMAs Shape-Memory Alloys
• NTE Negative Thermal Expansion materials
• a Shape-Memory Alloy is an alloy that "remembers" its original, cold- forged shape which, once deformed, returns to its pre-deformed shape upon heating.
• This material is a lightweight, solid-state alternative to conventional actuators such as hydraulic, pneumatic, and motor-based systems.
• Shape-Memory Alloys are the copper-zinc-aluminium- nickel, copper-aluminium-nickel, and nickel-titanium (NiTi) alloys but SMAs can also be created, for example, by alloying zinc, copper, gold and iron. The list is non-exhaustive.
• an energy recovery device comprising: an engine comprising a plurality of Negative Thermal Expansion (NTE) elements such as, but not limited to, Shape-Memory Alloys (SMAs), fixed at a first end and connected at a second end to a drive mechanism characterised by a holder configured with a plurality of slots adapted to receive the plurality of Shape Memory Alloy (SMA) or NTE elements.
• NTE Negative Thermal Expansion
• SMAs Shape-Memory Alloys
• the motivation behind the creation of the invention was to be able to shape the ends of the Shape Memory Alloy (SMA) or NTE elements in such a way that they may be kept in some sort of a support frame or holder such that the high force developed by their contraction can be safely transmitted in a manner resulting in mechanical work.
• SMA Shape Memory Alloy
• the holder comprises a plate perforated with suitably sized slots such that the elements can engage the slots and be secured in place.
• At least one element comprises a swage terminal end for restricting movement of the element when engaged with the holder. In one embodiment at least one element comprises a kinked or bent end for restricting movement of the element when engaged with the holder.
• At least one element comprises a dome shaped end for restricting movement of the element when engaged with the holder.
• the Negative Thermal Expansion (NTE) element comprises a Shape Memory Alloy.
• the Shape Memory Alloy comprises a Nickel-Titanium alloy.
• the Shape Memory Alloy (SMAs) or Negative Thermal Expansion (NTE) elements are arranged as a plurality of wires positioned substantially parallel with each other to define a core.
• an energy recovery device comprising a plurality of Shape Memory Alloy (SMAs) or Negative Thermal Expansion (NTE) elements arranged as a plurality of wires positioned substantially parallel with each other to define a core.
• a holder for use in an energy recovery device or engine, comprising a plurality of slots configured to receive a plurality of Negative Thermal Expansion (NTE) elements.
• the holder comprises a plate perforated with suitably sized slots such that the elements can engage the slot and be secured in place.
• an engine comprising a plurality of Shape Memory Alloy (SMA) or Negative Thermal Expansion (NTE) elements fixed at a first end and connected at a second end to a drive mechanism wherein a holder is configured with a plurality of slots adapted to receive the plurality of Shape Memory Alloy (SMA) or NTE elements.
• SMA Shape Memory Alloy
• NTE Negative Thermal Expansion
• Figure 2 illustrates views of a number of wires making up the engine core, according to one aspect of the invention
• Figure 3 illustrates a plurality of swaged wires fed into a bundle holder, according to one embodiment of the invention
• Figure 4 illustrates views of a number of wires making up the engine core, according to one aspect of the invention
• Figure 5 illustrates a plurality of kinked or bent wires fed into a bundle holder, according to one embodiment of the invention
• Figure 6 illustrates views of a number of wires with domed shape ends making up the engine core, according to one aspect of the invention
• Figure 7 illustrates a plurality of kinked or bent wires fed into a bundle holder, according to one embodiment of the invention.
• Figure 8 illustrates a wire bundle holder according to another aspect of the invention.
• the invention relates to a heat recovery system which can use either Shape Memory Alloys (SMAs) or other Negative Thermal Expansion materials (NTE) to generate power from low grade heat.
• SMAs Shape Memory Alloys
• NTE Negative Thermal Expansion materials
• the SMA engine 1 comprises a SMA actuation core.
• the SMA actuation core is comprised of SMA material clamped or otherwise secured at a first point which is fixed. At the opposing end, the SMA material is clamped or otherwise secured to a drive mechanism 2. Thus whilst the first point is anchored the second point is free to move albeit pulling the drive mechanism 3.
• An immersion chamber 4 is adapted to house the SMA engine and is also adapted to be sequentially filled with fluid to allow heating and/or cooling of the SMA engine. Accordingly, as heat is applied to the SMA core it is free to contract.
• the SMA core comprises a plurality of parallel wires, ribbons or sheets of SMA material.
• a deflection in and around 4% is common for such a core.
• a linear movement of approximately 4cm is available.
• the force that is provided depends on the mass of wire used.
• Such an energy recovery device is described in PCT Patent Publication number WO2013/087490, assigned to the assignee of the present invention, and is incorporated fully herein by reference.
• NiTi Nickel- Titanium alloy
• SMA or NTE material can be used in the context of the present invention.
• the wire's extremities have to be presented in such a way that they can be securely fixed in a metallic, or other material, support, hereinafter referred to as a bundle holder.
• the invention provides a holder, for use in an energy recovery device, comprising a plurality of slots configured to receive a plurality of Negative Thermal Expansion (NTE) or Shape Memory Alloy (SMA) elements.
• NTE Negative Thermal Expansion
• SMA Shape Memory Alloy
• FIG. 2 illustrates two wires that can be used to form a core indicated by the reference numerals 20 and 21 .
• the swage can be made in two ways, Swage A, 20, and Swage B, 21 .
• Swage A is located at the very end of the wire whereas Swage B is located just before the end of the wire, as illustrated in Figure 2.
• the type of swage used can be determined by the bundle holder or the space which the wire needs to fit into.
• Figure 3 illustrates a plurality of swaged wires 30 fed into a bundle holder 31 consisting of multiple slots 32 or holes or openings.
• the slots, openings or holes are designed to be smaller in diameter than the swage width, but marginally larger in diameter than the wire 30.
• FIG 4 Another embodiment of the invention is shown in Figure 4, where a high level of heat is used to place a bend or kink on each end of the wire, indicated by the reference numeral 41 .
• This acts as a stop when the wire 41 is loaded by resting against the surface of a wire bundle holder unit 42, as illustrated in Figure 5.
• the wires can be lined up beside each other on a single plane, thus facilitating a tightly packed arrangement of wires.
• Figure 6 illustrates another embodiment where one end of the wire 50 is dome shaped 51 to act as a stop when the wire is being held in a bundle or wire holder.
• the domed ends of the wire are larger than the holes in which the wires are placed, thus when a load is applied, the domes 51 act to resist pull-through, as illustrated in Figure 7.
• the assembly direction of the domes is irrelevant due to their cylindrical nature.
• the energy recovery device can comprise a plurality of Shape Memory Alloy (SMAs) or Negative Thermal Expansion (NTE) elements arranged as a plurality of wires positioned substantially parallel with each other to define a core.
• SMAs Shape Memory Alloy
• NTE Negative Thermal Expansion
• the wires for example, can be those described above with respect to Figures 2 to 7.
• the bundle holder has to eliminate the tedious and strenuous process of placing hundreds of these NiTi wires in some sort of support and reduce production time and costs.
• a casting alternative to the machined bundle holder can be used.
• the wires will not need to be swaged as they will be imbedded in a mould.
• Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods. Casting is a manufacturing process by which a liquid material is usually poured into a mould, which contains a hollow cavity of the desired shape, and then allowed to solidify. Not all metals are appropriate to be used as bundle holder materials.
• Shape- Memory Alloys contract when heated, while most metals expand.
• a non-reactive material can be selected in this case.
• alloyed materials that have zero thermal expansion while heated.
• Tetramethylammonium copper(l) zinc (II) cyanide has a zero or near zero thermal expansion between the temperatures of; 200K ⁇ 400K (i.e. -73.15 ⁇ 126.85°C)
• (1 -x)PbTi)03 - xBi(Mg,Ti)1 /203 has zero or near zero thermal expansion between the temperatures of; room temp ⁇ 500 °C
• the SMA will be at its smallest size (austenitic phase - the diameter of the wire decreases). This process will ensure the fixing of the wire, since the transition from austenite to martensite will result in an increase of diameter, so the cast will act as interference fit.
• Nitinol core In order for a Nitinol core to actuate a piston, a method must be identified for fixing a bundle of wires so that one end is fixed to the top of the core and the other end is attached to the piston.
• Figure 8 shows a proposed way of manufacturing a bundle holder that contains thousands of holes.
• the concept replaces the need for machining solid blocks of material by creating a mesh using wire versions of the same material.
• the wire would be cut into pre-defined lengths. It would then be placed into a jig which would maintain the distance between each wire. This would form a bottom layer.
• Another set of wires would then be placed on top of the first layer; however this layer would be rotated at a 90° angle to the first layer. From a top view this would have the same appearance as a bundle with several holes.
• the next step would be to fuse the top and bottom layer. This would increase the rigidity of the bundle and prevent the gap between wires from increasing or decreasing.
• One way that layers could be fused together would be by using a spot welding technique commonly used to weld panels and thin metals.
• This process consists of an Anode (-) and a Cathode (+).
• the anode is placed on the top layer while the cathode is positioned on the bottom layer.
• the anode and cathode press the two wires together at one junction.
• a current is then passed through the junction which causes it to heat, melt and fuse the wires together. This would be advantageous over drilling holes as a typical spot weld takes 0.63 seconds to fuse the wire. Naturally more time would need to be added to let the weld cool.
• the strength of the bundle holder can be increased by simply adding more layers. This would be particularly advantageous if a part of the bundle holder failed during service as it would allow the bundle holder to be repaired rather than recycled.
• the bundle holder must overcome some specific problems: 1 ) Transmitting the high-force, low displacement load of the NiTi wires during operation. 2) Enabling the close-packing of the wires, insofar as possible, to enable maximum heat transfer from the transiting water to the wire and vice versa.
• the bundle holder has to eliminate the tedious and strenuous process of placing hundreds of these NiTi wires in some sort of support and reduce production time and costs.
• Doming the wires at both ends after it has been cut means that no further work has to be done to the wire.
• These wires are then inserted into a bundle holder which has slots cut out. The width of these slots is equal to the diameter of the wire, which allows the dome at the top of the wire to rest on either side of the slot.
• the wire will be inserted into the bundle holder through a hole that is wider than each dome at the end of every row. This hole will then have a screw threaded into it to hold the wires in place and complete the bundle. This method also allows both the top and bottom layer of the bundle to be inserted at the same time.
• SMAs Shape Memory Alloys
• NTE materials can be used for certain types of applications.
• Shape memory polymers are: polyurethanes, polyurethanes with ionic or mesogenic components made by prepolymer method, block copolymer of polyethylene terephthalate (PET) and polyethyleneoxide (PEO), block copolymers containing polystyrene and poly(1 ,4-butadiene), and an ABA triblock copolymer made from poly(2-methyl-2-oxazoline) and polytetrahydrofuran, amorphous polynorbornene.
• PET polyethylene terephthalate
• PEO polyethyleneoxide
• ABA triblock copolymer made from poly(2-methyl-2-oxazoline) and polytetrahydrofuran, amorphous polynorbornene.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Springs (AREA)
• Vehicle Cleaning, Maintenance, Repair, Refitting, And Outriggers (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

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Cited By (6)

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• 2014
  • 2014-05-30 GB GBGB1409679.6A patent/GB201409679D0/en not_active Ceased
• 2015
  • 2015-05-29 JP JP2017514975A patent/JP2017530295A/ja not_active Withdrawn
  • 2015-05-29 EP EP15731858.5A patent/EP3149327B1/en active Active
  • 2015-05-29 WO PCT/EP2015/062047 patent/WO2015181388A2/en not_active Ceased
  • 2015-05-29 US US15/315,083 patent/US9995289B2/en active Active

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