摘要:
A long life, low cost, high-temperature, high efficiency thermoelectric module. Preferred embodiments include a two-part (a high temperature part and a cold temperature part) egg-crate and segmented N legs and P legs, with the thermoelectric materials in the three segments chosen for their chemical compatibility or their figure of merit in the various temperature ranges between the hot side and the cold side of the module. The legs include metal meshes partially embedded in thermoelectric segments to help maintain electrical contacts notwithstanding substantial temperature variations. In preferred embodiments a two-part molded egg-crate holds in place and provides insulation and electrical connections for the thermoelectric N legs and P legs. The high temperature part of the egg-crate is comprised of a ceramic material capable of operation at temperatures in excess of 500° C. and the cold temperature part is comprised of a thermoplastic material having very low thermal conductivity.
摘要:
A thermoelectric module having a gapless insulating eggcrate providing insulated spaces for a large number of p-type and n-type thermoelectric elements. The absence of gaps in the walls of the spaces virtually eliminates the possibility of interwall shorts between the elements. Electrical connections on both the hot and cold sides of the module electrically connect the elements in series or in parallel as desired. Usually, most or all of the elements will be connected in series. In a preferred embodiment, the gapless eggcrate is formed from a high temperature plastic. In a preferred embodiment, two lead wires are added before adding the hot and cold side electrical connections. In this embodiment, electrical connections on the hot and cold sides comprise a thin layer of molybdenum and a coating of aluminum over the molybdenum. The surfaces are ground down to expose the insulating eggcrate walls except where connections between the elements are desired. In this preferred embodiment a seal is then applied over both the hot and cold surfaces. The seal preferably is comprised of a very thin electrically insulating layer and over this electrically insulating layer a thin metal layer is provided.
摘要:
A super-lattice thermoelectric device. The device is comprised of p-legs and n-legs, each leg being comprised of a large number of very thin alternating layers of two materials with differing electron band gaps. The n-legs in the device are comprised of alternating layers of Si and SiC. The p-legs are comprised of alternating layers of B4C and B9C. In preferred embodiments the layers are about 100 angstroms thick. Thermoelectric modules made according to the present invention are useful for both cooling applications as well as electric power generation. This preferred embodiment is a thermoelectric 10×10 egg crate type module about 6 cm×6 cm×0.76 cm designed to produce 70 Watts with a temperature difference of 300 degrees C. with a module efficiency of about 30 percent. The module has 98 active thermoelectric legs, with each leg having more than 3 million super-lattice layers.
摘要:
A low-cost thermoelectric module utilizing a greatly reduced quantity of thermoelectric material as compared to similar prior art thermoelectric modules. An egg crate design containing thermoelectric elements is utilized in the present invention. However, the walls of the egg crate in the parts of the module separating the thermoelectric elements are made thick so that the total cross sectional area of the elements is less than 75 percent of the total module cross sectional area. The spaces above and below the elements are filled with a high heat and electric conducting material such as aluminum. This produces funnel-shaped conductors funneling heat and electric current into and out of each of the thermoelectric elements. The payoff to this approach is that the heat flux through the hot and cold module surfaces can be maintained while producing the same power output with about half the thermoelectric material or less. Avoiding any significant increase in heat flux through the module surface means avoiding increases in temperature drops normally encountered at the module surfaces.
摘要:
A super-lattice thermoelectric device. The device includes p-legs and n-legs, each leg having a large number of alternating layers of two materials with differing electron band gaps. The n-legs in the device are comprised of alternating layers of silicon and silicon germanium. The p-legs includes alternating layers of B4C and B9C. In preferred embodiments the layers are about 100 angstroms thick. Applicants have fabricated and tested a first Si/SiGe (n-leg) and B4C/B9C (p-leg) quantum well thermocouple. Each leg was only 11 microns thick on a 5 micron Si substrate. Nevertheless, in actual tests the thermocouple operated with an amazing efficiency of 14 percent with a Th of 250 degrees C. Thermoelectric modules made according to the present invention are useful for both cooling applications as well as electric power generation. This preferred embodiment is a thermoelectric 10×10 egg crate type module about 6 cm×6 cm×0.76 cm designed to produce 70 Watts with a temperature difference of 300 degrees C with a module efficiency of about 30 percent.
摘要:
A thermoelectric conversion system including a burner assembly and a number of thermoelectric conversion modules for converting thermal energy resulting from the operation of the burner assembly into electrical energy. The burner assembly includes a central combustion chamber and a number of longitudinally extending heat pipes each having an evaporator section and a condenser section with the evaporator sections positioned at spaced locations around the combustion chamber. The system also includes flow means for causing the hot gases provided by the combustion chamber to flow past the evaporator sections. The heat pipes and the conversion modules correspond in number, with each of the modules connected in heat transfer relationship with a corresponding heat pipe condenser section.
摘要:
A miniature thermoelectric module for generating electric power from low power heat sources in the range of a fraction of a Watt to a few Watts. The module comprises an array of thermoelectric elements, each element having a cross section of less than 0.001 square inch and a length of at least 0.25 inch. The elements are separated from each other with a polyimide insulator sheet in a checkerboard array. In a preferred embodiment, the modules are fabricated by hot pressing a stack of alternating plates of p and n doped thin plates all separated by thin sheets of a polyimide insulator material to produce a pressed stack of p and n doped layers. The stack is then sliced to produce layered plates which are then stacked with insulating polyimide layers positioned between the layered plates to produce the checkerboard array of p and n thermoelectric elements. Contacts are applied to electrically connect all of the elements. In a preferred embodiment, the contacts are applied by first sputtering a thin layer of gold, then welding gold tabs, and then blasting away the excess sputtered gold. In one preferred embodiment, the contacts connect all of the elements in series. In another preferred embodiment, the elements are connected in a series-parallel circuit. In a preferred embodiment, the module is utilized in a generation unit with a 1-Watt radioactive heat source to produce about 40 mW of electric power at 5.5 Volts which is converted to 12 Volts with a DC to DC converter.
摘要:
A combustion heat powered portable electronic device. At least one thermoelectric module is sandwiched between a hot block heated by a combustion heat source and a cold-side heat sink and provides electric power to a portable electronic device from the temperature difference. An electric circuit provides power for purposes of operating the portable electronic device either directly or indirectly by charging a rechargeable battery which in turn provides power to the electronic device. In a preferred embodiment the combustion heat source is a catalytic combustion unit. The hot block and/or cold side heat sink can be integrated into a single unit with the thermoelectric module. In a preferred embodiment the cold side heat sink is cooled by fins cooled by air driven by a forced air fan powered by the thermoelectric module.
摘要:
A method for fabricating a thermoelectric module with thermoelectric elements installed in an gapless eggcrate. This gapless eggcrate provides insulated spaces for a large number of p-type and n-type thermoelectric elements. The absence of gaps in the walls of the spaces virtually eliminates the possibility of interwall shorts between the elements. Thermoelectric elements, both p-type and n-type, are inserted into the insulated spaces in the gapless eggcrate to provide the desired thermoelectric effects . Electrical connections are established on both the hot and cold sides of the module to connect the thermoelectric elements in series or parallel as desired. Normally, most or all of the elements will be connected in series. In a preferred embodiment the gapless eggcrate is formed from a high temperature plastic. P-type thermoelectric material is extruded and then sliced to form p-type thermoelectric elements, and n-type thermoelectric material is extruded and sliced to form n-type thermoelectric elements. The thermoelectric elements are loaded in the eggcrate in an arrangement to put them all in series when a metal spray is applied to the hot and cold sides. Two electrical leads are applied and electrical connections on both the hot and cold sides are provided using a metal thermal spray technique. A thin layer of molybdenum is sprayed on one of the surfaces and then a coating of aluminum is sprayed over the molybdenum. These steps are repeated for the other side. Then the surfaces are ground down to expose the insulating eggcrate walls except where connections between the elements are desired. A seal is then applied over both the hot and cold surfaces. The seal preferably is very thin electrically insulating layer and over this layer a layer of aluminum is provided.
摘要:
A thermoelectric converter includes a heat source having a mating face and a heat sink also having a mating face. The converter also includes a thermoelectric conversion module positioned between these faces. The module includes an electrically insulative holder having a first side positioned adjacent the heat source and a second side disposed adjacent the heat sink. The holder includes spaced parallel first walls and spaced parallel second walls extending normal to the first wall so that these first and second walls define an array of compartments with each compartment containing a thermoelectric element. The module further includes a compressed resilient, thermally conductive pad positioned in each compartment.