摘要:
A thermoelectric generator utilizing a number of thermoelectric modules to produce electric power from waste heat when waste heat is available and from an alternate heat source when waste heat is not available. In both cases hot gasses are directed along several separate paths so that all of the modules are provided with approximately equal hot side temperatures. In a preferred embodiment the engine exhaust exits into an octagonally-shaped plenum into eight separate heat exchangers. Eight modules are mounted in each of the heat exchangers for a total of 64 modules. Preferred embodiments of the present invention include an auxiliary combustion burner-blower unit producing a hot exhaust that exits into the plenum to provide electric power when the truck is not operating. Valve features are provided to control the temperature and exhaust flow rate through the generator.
摘要:
A multi-layer superlattice quantum well thermoelectric material comprising at least 10 alternating layers has a layer thickness of each less than 50 nm, the alternating layers being electrically conducting and barrier layers, wherein the layer structure shows no discernible interdiffusion leading to a break-up or dissolution of the layer boundaries upon heat treatment at a temperature in the range from 50 to 150° C. for a time of at least 100 hours and the concentration of doping materials in the conducting layers is 1018 to 1023 cm−3 and in the barrier layers is 1013 to 1018 cm−3.
摘要:
A thermoelectric module comprised of a quantum well thermoelectric material with low thermal conductivity and low electrical resitivity (high conductivity) for producing n-legs and p-legs for thermoelectric modules. These qualities are achieved by fabricating crystalline quantum well super-lattice layers on a substrate material having very low thermal conductivity. Prior to depositing the super-lattice thermoelectric layers the low thermal conductivity substrate is coated with a thin layer of crystalline semi-conductor material, preferably silicon. This greatly improves the thermoelectric quality of the super-lattice quantum well layers. In preferred embodiments the super-lattice layers are about 4 nm to 20 nm thick. In preferred embodiments about 100 to 1000 of these super-lattice layers are deposited on each substrate layer, to provide films of super-lattice layers with thicknesses of in the range of about 0.4 microns to about 20 microns on much thicker substrates. The substrates may be a few microns to a few millimeters thick. The thermoelectric films are then stacked and fabricated into thermoelectric p-legs and n-legs which in turn are fabricated into thermoelectric modules. These layers of quantum well material may in preferred embodiments be separated by much thicker layers of thermal and electrical insulating material such that the volume of insulating material in each leg is at least 20 times larger than the volume of quantum well material.
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 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 compact high power density thermoelectric generator for producing electric power from a hot fluid heat source. In preferred embodiments the HPD TEGs provide a wide range of electric power generators with a large range of outputs utilizing a modular approach featuring: (1) a basic building TEG block which can be combined with a number of the same type of building blocks to provide (2) a basic TEG section and a number of these basic TEG sections can be combined to provide this wide range of (3) HPD TEG systems. In these preferred embodiments the heat sources could include the exhaust of a truck, car boat, and other generators engines.
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:
Thermoelectric elements for use in a thermoelectric device. The thermoelectric elements have a very large number of alternating layers of semiconductor material deposited on a very thin flexible substrate. The layers of semiconductor material alternate between barrier semiconductor material and conducting semiconductor material creating quantum wells within the thin layers of conducting semiconductor material. The conducting semiconductor material is doped to create conducting properties. The substrate preferably should be very thin, a very good thermal and electrical insulator with good thermal stability and strong and flexible. In a preferred embodiment, the thin organic substrate is a thin polyimide film (specifically Kapton.RTM.) coated with an even thinner film of crystalline silicon. The substrate is about 0.3 mills (127 microns) thick. The crystalline silicon layer is about 0.1 micron thick. This embodiment includes on each side of the thin Kapton.RTM. substrate about 3,000 alternating layers of silicon and silicon-germanium, each layer being about 100 .ANG. and the total thickness of the layers being about 30 microns. Preferably, the silicon layer is applied in an amorphous form and heated to about 350.degree. C. to 375.degree. C. to crystallize it. In other preferred embodiments, the substrate material is thin films of other organic materials or thin films of inorganic materials such as silicon.
摘要:
A stovepipe thermoelectric generator. The unit fits in a stovepipe of a coal or wood stove. At least one thermoelectric module is sandwiched between a hot side fin unit with fins extending into the flow of exhaust gases and a cold side fin unit with fins cooled by forced room air. A damper controls exhaust gas flow through a heat chamber, directing the exhaust gas through a generating side and a bypass side depending on a temperature indication. This prevents heat damage to the thermoelectric module. At least one fan is provided to force room air through cooling fins of the cold side fin unit An electric circuit is described for providing power for the fan and providing additional electric power for purposes such as charging a battery.
摘要:
A segmented lead telluride egg-crate thermoelectric module. In preferred embodiments N legs and P legs are segmented into at least two segments. The segments are chosen for their figure of merit in the various temperature ranges between the hot side and the cold side of the module. In preferred embodiments a low-temperature egg-crate, molded from a liquid crystal polymer material, having very low thermal conductivity holds in place and provides insulation and electrical connections for the thermoelectric N legs and P legs at the cold side of the module. A castable ceramic capable of operation at temperatures in excess of 500° C. is used to provide electrical insulation between the legs at the hot side of the module.