JP2012178533A5 - - Google Patents

Description

According to Non-Patent Document 1, in Bi ₂ Te ₃ , when the length becomes shorter than the phonon mean free path, the phonon conducts ballistically in that direction. The heat transfer in the thin wire is characterized by the magnitude relationship between the length of the thin wire, the thickness in the direction perpendicular thereto, and the mean free path of the phonon when the heat transfer direction is taken along the length of the thin wire . When the length and thickness are longer than the phonon mean free path, the heat conduction follows the Fourier law and is a diffusive phonon. When the thickness is shorter than the phonon mean free path , the phonon conducts ballistic phonon in the thickness direction but heats more than the value characterized by diffusive phonon conduction due to phonon scattering due to the surface roughness of the wire. Conduction is reduced. When the length is shorter than the phonon mean free path, the ballistic phonon conduction, if not affected by the surface roughness, results in greater thermal conduction in the length direction than that characterized by diffusive phonon conduction. On the other hand, Non-Patent Document 2 evaluates the dependence on the amount of heat transfer in the thickness direction using non-equilibrium molecular dynamics for nanotubes. In a single-sheet nanotube, the surface roughness is reduced and there is an influence of ballistic phonon conduction in the length direction up to 1.6 μm at room temperature. As a result, the heat conduction is greater than the value characterized by diffusive phonon conduction. On the other hand, when the spatial dimension of the conductive material is small or when it is layered, the electrical conductivity is the allowance of the electrons carrying the current flowing in a narrow direction if the cross-sectional area traversed when the electrons move is small. The energy state interval generated is large and the scattering of electrons is less likely to occur, and the density of states of electrons changes depending on the spatial dimension, resulting in improved electrical conduction. Thermoelectric materials such as nanothin films, superlattices, and nanowires take advantage of the improvement in the figure of merit of thermoelectric materials at lower dimensions.

Thermoelectric materials currently in use include intermetallic compounds such as bismuth / tellurium and silicide compounds. Also, new thermoelectric materials include cage -type materials such as layered cobalt oxides and clathrate compounds, and those using strongly correlated electrons. The maximum use temperature of the PbTe-based compound is about 950K, but n-type PbTe has an about 450K maximum performance index of 1.7 × 10 ⁻³ K ⁻¹ when the electron concentration by impurity doping is 5 × 10 ²⁵ m ^−3. When the electron concentration is increased, the maximum performance index gradually decreases in proportion. At 7 × 10 ²⁵ m ⁻³ , the maximum performance index becomes 1.2 × 10 ⁻³ K ^{−1 at} about 800K. PbTe-based compound hot end temperature at the cold end temperature 300 K has a wide temperature range is 950K.

In Non-Patent Document 3, BiSbTe crystals are crushed to a few tens of nanometers in argon and then hot-pressed and hardened in order to increase the figure of merit by reducing thermal conductivity without impairing electrical conductivity. . An “amorphous structure between crystals” is produced at low cost between crystals, and ZT = 1.4 with 40% improvement. In Patent Document 6, in order to prevent heat flow and flow current, a thermoelectric material in which a grain boundary layer composed of a glass layer is not substantially present at the interface between crystals to prevent lattice vibration is 100 nanometers or less. Is used. Here, a thermoelectric material having a cage structure is used and formed on a substrate by a normal temperature impact solidification phenomenon by an aerosol deposition method.

How the working material moves in the space between the objects depends on the potential of the working material. In the vicinity of the surface in contact with the space, the potential is lowered by the electromirror effect. Its potential, by simulation, or analytically determined as non-patent document 4.

In thermoelectric power generation using radioisotopes, the radioactive isotope uses the radiation particle beam in the course of natural decay, and the decay heat of the part containing the radioisotope or the thermal energy generated at that time is collected in the collection part of the radiation particle beam. It is used for thermoelectric power generation.

と表される。ここで、Ｔ_Ｈ、Ｔ_Ｃは高温および低温接合部温度、ｍ＝Ｒ_Ｌ／Ｒである。Ｒ、Ｒ_Ｌは内部抵抗および外部負荷である。電極−熱電材料間、異種熱電材料間などの電気的接触抵抗Ｒ_ｃの熱発電モジュール効率ηへの影響は

となる。ここで、

である。非特許文献６によるとＳｉ／ＳｉＯ_２基板上にＣｕ／Ｎｉ電極をメタライズされたところに電気化学的堆積法で熱電材料Ｂｉ_２Ｔｅ_３を高さＨで断面積がＡの形状に製作すると、その抵抗Ｒ_{Ｂｉ２Ｔｅ３}はＲ_{Ｂｉ２Ｔｅ３}＝ρ_{Ｂｉ２Ｔｅ３}Ａ／ＨとなるのでＰはＨ／Ａに比例することになる。ここでρ_{Ｂｉ２Ｔｅ３}はＢｉ_２Ｔｅ_３の抵抗率である。Ｈ／Ａを一定で、Ｈをマイクロからナノサイズに小さくすると、必要な断面積は減少し、出力密度が増えることが報告されている。実用用途として、人体と大気間の温度差でＰ〜１０数μＷが得られている。Systems using thermoelectric materials are optimized by selecting the type / shape / size of the thermoelectric material and the type / thickness of the surrounding heat insulating material according to the temperature range and heat quantity to be used. Heat should be dissipated using air-cooled fins, air-cooled fins with fans, or water cooling, and heat exchange with other structures must also be considered. The thermoelectric material is attached to the electrode / structure by grease, adhesion, or soldering. Also, to prevent moisture from entering the inside of the module in the system, seal it with epoxy resin, silicone resin, etc., so that there is no electrochemical elution of solder or diffusion of grease and adhesives. Yes. Such grease and sealing material cause heat conduction between the low-temperature part and the high-temperature part of the module, which reduces the performance.
The thermoelectric power output P is

It is expressed. Here, T _H and T _C are high temperature and low temperature junction temperature, m = R _L / R. R and _RL are an internal resistance and an external load. Electrode - between the thermoelectric material, the electrical effect of the thermoelectric module efficiency η of the contact resistance R _c, such as between different thermoelectric material

It becomes. here,

It is. According to Non-Patent Document 6, when a Cu / Ni electrode is metallized on a Si / SiO ₂ substrate, the thermoelectric material Bi ₂ Te ₃ is manufactured to have a height H and a cross-sectional area A by electrochemical deposition. Since the resistance R _Bi2Te3 is R _Bi2Te3 = ρ _Bi2Te3 A / H, P is proportional to H / A. Here, ρ _Bi2Te3 is the resistivity of Bi ₂ Te ₃ . It has been reported that when H / A is constant and H is reduced from micro to nano size, the required cross-sectional area decreases and the power density increases. As a practical use, P to several tens of μW is obtained due to a temperature difference between the human body and the atmosphere.

（＋はゼーベック効果による発電動作、−はペルチェ効果による冷却動作）
なるエネルギー収支バランスが生じる。システム効率ηは

である。ηを最大化するには
１）使用するモジュールの能力と目標性能とをバランスさせる。
２）モジュール単体の性能を適当な経済性で最大発揮できるようにする。
を考慮に入れる。
例えば、発電稼動のシステム効率η_ｇｅｎは

である。モジュール内部抵抗Ｒ_ｉ ^ＭＯＤと外部仕事する際の抵抗Ｒ_ｏの比ｍ＝Ｒ_ｏ／Ｒ_ｉ ^ＭＯＤについて、η_ｇｅｎを最大にするｍになるように最適化する。最大効率η_ｍａｘは温度条件と熱電材料の物性値すなわち性能指数のみによって決まることが知られている。また、冷却稼動のシステム効率η_ｒｅは

で表される。η_ｒｅを最大にするｍになるように最適化する。その結果、Ｒ_ｏに流れる作業物質流が最小化されＰが最小になる。Surface contacting the coating is an electrode plate with an insulator in contact with a certain heat source to that different heat source is a pair of film is an electrode plate with an insulator. A system is configured between the electrode pairs in units of π-type modules. For example, in order to increase the output current in power generation operation, in order to increase the parallel arrangement or the output voltage on a single coated electrode plate so that the legs of the plurality of π-type modules have the same thermoelectric material, respectively. In addition, there are a series arrangement in which π-type modules are turned upside down and pairs having different polarities are arranged on a single coated electrode plate, or a composite arrangement of these. Thus, the plurality of π-type modules are assembled from a plurality of pairs of heat sources, electrodes, and thermoelectric materials having different polarities. It is necessary to change the figure of merit of thermoelectric material pairs to improve module performance . At this time, the cross-sectional areas and lengths of the thermoelectric material pairs of each π-type foot are different. The thermoelectric system obtains a heat quantity Q _in from one heat source and applies it to the thermoelectric module, and the heat quantity flows through the thermoelectric material and is released to the other heat source as a heat release quantity Q _out . During this time, electrical work P acts on the outside world. That is,

(+ Is power generation operation by Seebeck effect,-is cooling operation by Peltier effect)
The energy balance becomes. System efficiency η is

It is. To maximize η 1) Balance the capabilities of the modules used and the target performance.
2) To maximize the performance of a single module with appropriate economic efficiency.
Take into account.
For example, the system efficiency η _gen for power generation operation is

It is. The ratio m = R _o / R _i ^MOD of the module internal resistance R _i ^MOD and the resistance R _{o at} the time of external work is optimized so as to be m that maximizes η _gen . It is known that the maximum efficiency η _max is determined only by temperature conditions and physical property values of thermoelectric materials, that is, performance indexes. The system efficiency η _{re for} cooling operation is

It is represented by Optimize for m to maximize _ηre . As a result, P working substance flowing through the R _o is minimized is minimized.

In the first aspect, as shown in FIG. 1, a submicrometer space 12 is arranged so as to prevent heat transfer in the direction in which the heat flow or working substance flow of the thermoelectric materials 10 and 11 is transmitted. The heat transfer due to the existence of quasi-particles such as lattice vibration, magnon, and spin wave while maintaining almost the same or larger value as the working substance flow in the two left and right thermoelectric materials 10, 11 It is characterized by improving the efficiency of the thermoelectric system by suppressing the thermal fluctuations due to, and the quantum fluctuations at low temperatures. The distance between the pinnacle surfaces 13 between the terminals of the two thermoelectric materials 10, 11 that make up the space 12 in FIG. 1 depends on the absolute temperature T at the pinnacle surface 13, “distance” L _max (T) Exceeding this makes it possible to almost ignore the heat transfer due to phonons in the space 12. Incidentally, compared to the lattice vibration _{L max} (T) magnon and _{L max,} such as spin waves (T) is much smaller. L _max (T) can be obtained from the actual measurement range of the distance between the atomic force microscope and the measurement surface. On the other hand, by making the space below sub-micro, it is possible to avoid being limited to the space charge of the working substance. The working material flow in this portion can be made larger by making the size of the space closer to L _max (T) from submicrometers. Hereinafter, a space including one or more of the above-described structures so as to prevent transmission of heat flow or working material flow is abbreviated as a space portion. Either one of the thermoelectric materials 10 and 11 can be a good working substance conductor other than the thermoelectric material. During operation, conduction of thermal energy due to radiation energy loss in the space portion depends on the temperature difference between the opposed terminals 13 and 14 in the space portion and the area to be opposed. When terminals 13 and 14 are wider than L _max (T) but narrower than sub-micrometers, the temperature difference between thermoelectric materials sandwiching the space and between thermoelectric materials and electrodes is about several Kelvin, so that almost no loss can be suppressed. . Further, by making the space 12 into a vacuum, heat transfer by convection there can be suppressed. Although the thermal conductivity in the metal is mostly due to heat conduction component kappa _c classical system working substance and becomes a semiconductor, the thermal conductivity component kappa _ph component due to the lattice becomes larger. By utilizing a difference in factors of physical transfer phenomena kappa _c and kappa _ph in space portion, a contrivance for reducing the zero and kappa _c the kappa _ph.
If the κ _ph component and the κ _c component are the same, the performance index of Equation 1 can easily be doubled if only the heat conduction by phonons is suppressed and the others remain unchanged. Thermoelectric materials with good figure of merit have the same κ _ph and κ _c components .
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments in accordance with the principles of the invention and together with the description schematically illustrate such embodiments. To do. The conceptual diagram of the invention emphasizes the essence of the invention.

  By inserting the space portion, the space portion may mainly hinder the work material flow during power generation operation. The work substance is released from the surface using heat, electric field, electromagnetic waves, and the like. When the working substance moves in the direction from 11 to 10 in FIG. 1, the working substance is excited in the space portion by the excitation of the working substance by energy such as heat in the thermoelectric materials 13, 14 or in the vicinity of the spire surface 13. By tunneling through the potential barrier, the working substance moves to the space portion 12 and moves to the counter electrode 14. According to macroscopic quantum mechanics, the probability of tunneling through the potential barrier of the working material at the space interface 13 decreases exponentially as the working material mass increases, but fluctuations are suppressed when operating at very low temperatures. L _max Since (T) becomes smaller and the distance between the terminals 13 and 14 can be made narrower, a thermoelectric conversion element using ions having a large work substance mass is also possible. In the case of electrons and holes in a semiconductor, the mass of holes is generally several times the mass of electrons. As a result, when the space 12 is separated to some extent, electrons are tunneled through the p-type semiconductor rather than through holes. When the thermoelectric material 11 is a semiconductor and the steeple 13 is a metal, the semiconductor 11 and the steeple 13 are preferably ohmic junctions during power generation operation and Schottky junctions during cooling operation.

  When voltage is applied to the space, the height of the spire is high and the distance between the terminals of the surfaces 13 and 14 is L _max If the radius is closer to (T) or the radius of curvature is small at the convex tip portion of the spire surface 13 in FIG. 1, the electric field becomes larger, and the potential of the working substance in the vicinity of the spire surface 13 of charged particles as the working substance. The height and thickness of the barrier are greatly reduced. The maximum electric field is in the vicinity of the convex tip of the steeple surface 13, and an enhancement factor β that depends on the height from the joint surface of the thermoelectric material 11 and the steeple surface 13 to the convex tip of the steeple surface 13 and the radius of curvature of the convex tip is used. Its maximum electric field E _Convex Is E _Convex = ΒE _s It becomes. Where E _s Is an electric field in the vicinity of a flat plate when the working substance discharge surface 13 of the thermoelectric conversion element is a flat plate. This value is 10 for the working material to pass through the tunnel. ⁹ It must be larger than [V / m]. The electric field can be increased by reducing the radius of curvature of the steeple surface 13, increasing the height of the steeple, and shortening the distance between the terminals of the surfaces 13 and 14. The current depends on the electric field in the vicinity of the surface of the tip of the spire and the work substance emission area. It flows according to the space charge distribution.

  When the voltage applied to the space 12 in FIG. 1 cannot increase the intensity of the electric field generated in the space portion to a required value or when the working material flow is small, the charged particle receiving terminal which is the working material as shown in FIG. By deforming the shape of the surface 22 so as to surround the charged particle emission spire surface 24 which is a working substance, the maximum electric field E _Convex The value of becomes higher than before deformation, and the area where charged particles are emitted increases. There is also a possibility that the electric field of other pointed parts will be maximized. As a result, the amount of charged particle emission increases. In this way, by changing the shape of the surfaces 22 and 24, the working substance flow in the space 23 due to the electric field emission of the charged particles as the working substance causes the working substance flow of any of the heat conducting materials 20 and 21 to sandwich the space. It is possible to improve the figure of merit of Equation 1 by making it as close as possible or better. When the working material flow rate is small, the working material flow rate can be increased by forming a plurality of spire structures 30, 31, and 32 in parallel as shown in FIG.

Claim 1 is a thermoelectric conversion element in which a space portion where the counter terminal pairs 13 and 14 of FIG. 1 are separated exists. However, even if the above method is used, the working substance is difficult to move in the space portion, and conduction in the space portion is performed. There are cases where the working substance flow to be performed is less than the working substance flow in the heat conducting material at both ends sandwiching the space portion. In this case, the space 62 is bridged with a working material good conductor as shown in FIG. 6, so that the heat flow is suppressed and a member longer than L _max (T) is used to face the end surface 61 to the end surface 60. It is possible to suppress the heat flow due to direct grid vibration and obtain a larger working material flow when separated. As 63 in FIG. 6, at least one side of a columnar shape having a diameter of several nanometers (FIG. 4a), a cylindrical shape having a thickness of several nanometers (FIG. 4b), or a plane perpendicular to the direction of the working substance flow, When a plate-like member having a length of several nanometers (FIG. 4c) is used, the influence of phonon scattering on a surface that is not a cross section representing the thickness becomes more significant than the influence of phonon scattering outside the surface. In addition, in this case, there is a state where the working substance is not easily scattered in the direction other than the working substance flow direction, and the surface has a small cross-sectional area that does not significantly affect the scattering of the working substance in the working substance flow direction. If so, the working material flow is increased. Spatial dimension influences the working material flow. When the working material flow inside the bridging member is smaller than the working material flow of the thermoelectric material at both ends sandwiching the bridging member with this cross-sectional area, the cross-sectional area of the working material good conductor is increased or a plurality of working material good conductors are used (hereinafter referred to as the working material good conductor). , A space that is cross-linked with a fine structure is abbreviated as a space part). A plate-like member having a thickness of several nanometers (FIGS. 4B and 4C) has a worse working substance flow than a thin member (FIG. 4A), but is better than a three-dimensional bulk. As shown in FIG. 6, the figure of merit is enhanced by having a space portion where a pair of opposite terminals are connected by a thin conductor body 63 between the thermoelectric conversion elements 60 and 61 as shown in FIG.

The current is transmitted by a classical working material or a quantum working material. Heat is transmitted along with what generates electric power, or is transmitted by lattice vibration, radiation, or the like. When the space portion is narrow, or when the space portion is cross-linked by a thin line , the quantum work material can be used at a very low temperature. Hereinafter, the space part bridged by the thin line is abbreviated as a connected space part. In the presence of a magnetic field, the resistance of the work substance is added due to the Hall effect or the Nernst effect, or the heat flow, current and voltage do not point in the same direction. It is a distance of L _max (T) or more with respect to lattice vibration, and the performance index of the thermoelectric material is obtained by providing a space portion or a connected space portion so as to prevent the heat transfer associated with the working material flow. Improve.

When an electromagnetic wave or radiation containing light is applied to the interface of the thermoelectric material 81 that contacts and opposes the space 82 in FIG. 8, the energy is given to the work substance. As a result, the working substance becomes a high energy state, and the energy exceeding the potential barrier of the working substance to the space portion is reduced.
In addition, the width of the potential barrier that tunnels through the potential of the working material is reduced. Or the state of the working substance which is easy to jump out on the surface can be taken. The radiation source primarily serves to help move the work material from the work material discharge surface to the work material receiving surface. Claim 3 is a working substance moving from the electromagnetic wave supply part or radiation source disposed in the space 82 to the working substance moving in the space 82 in FIG. 8, the material 81 having the discharge terminal surface, or the working substance to be released from the surface into the space 82. The working material can be easily conducted through the space 82. It is also possible to embed the radiation source in the surface portion of the thermoelectric material 80 facing the work substance discharge terminal or the discharge terminal 81. When the radiation source is placed in the vicinity of the working substance discharge terminal 81 or embedded, the heat generated by the radiation decay can be used. When light is used, it is guided into the space using an optical fiber or the like to irradiate the work substance discharge surface. Alternatively, the distance between the counter terminals at the center portion in the space portion is short, and the light can reach the inside by increasing the distance between the counter terminals on the outside. In FIG. 8, the effect of field electron emission can be included by making 81 a spire structure.

In the heat conversion element including the space portion or the connected space portion, the mobility of the working material is not uniform in position and time. At the interface where the amount of inflow and outflow of electric charge of the working material is different, the inflow or outflow of the electric charge of the working material is large and the electric charge is accumulated, thereby obstructing the working material flow. Further, when the charge of the working substance is accumulated, the heat conversion element is deteriorated. The fourth aspect of the present invention is characterized in that an effect of diffusing a working substance locally present on the surface of the working substance receiving terminal surface or the discharging terminal surface is obtained by coating the working substance good conductor thin film. The coating of the working material good conductor thin film reduces the influence of deterioration by strengthening the element or preventing concentration of heat, and increases the amount of energy obtained per unit time. The potential of the working substance against movement into the terminal based on the local concentration difference between the working substance receiving terminal surface or the discharge terminal surface and the thermoelectric material by coating the working material receiving terminal surface or the discharge terminal surface with a good working material conductor The barriers can be reduced, or destruction caused by excessive or insufficient working substance concentrations can be reduced.

In a thermoelectric conversion element having a space portion, the terminal portion deteriorates due to impact or mechanical destruction due to local movement in the space as the working substance moves in the space portion. In addition, by encapsulating the gas or metal vapor, the space, the collision between the work material and gas molecules, changing the energy state in the space of the working substance. In order to eliminate thermoelectric material destruction other than friction caused by working substance excitation in the release surface or the receiving surface after passing through the work substance release surface, the surface may be coated with another substance or joined with another substance. It is protected by increasing interatomic bonding force or by making coordinated movements in atomic groups. Alternatively, a cage-type thermoelectric material can be used for the work substance receiving terminal to absorb vibration and prevent deterioration.

In the method of combining segmented thermoelectric materials, the durability of the thermoelectric system depends on the temperature distribution at the time of using the interface between the thermoelectric material and the electrode part, the interface between the segments, the thermal expansion of the space part, and the thermal fluctuation of the heat source. It is determined by fatigue due to thermal stress due to the influence of temperature change during operation. For this reason, contact resistance between the thermoelectric material and the electrode is increased, and as a result, burnout due to Joule heat of fatigue cracks has been reported. By providing the space portion, mechanical damage due to thermal expansion can be prevented. Since the distance between the opposite terminals is larger than L _max (T), fatigue due to thermal fluctuation due to quantum fluctuation at low temperature, fluctuation of the interface due to temperature change during operation, and movement between interfaces other than the working substance Destruction is suppressed.

In power generation in operation during power generation in which the temperature difference between the high-temperature part and the low-temperature part is wide, the electromotive force can be increased by arranging a plurality of stages. As shown in FIG. 10, it is assumed that a plurality of segmented thermoelectric materials or good working substance conductors are used. At this time , the height of the nano-sized conductive pillar or coil on the surface of the thermoelectric conversion element 101 and the radius of curvature of the working substance discharge surface influence the deformation of the working substance from the bulk density of the thermoelectric material and the movement of the working substance. However, these values, the working substance discharge surface area of these conductor columns and coils, the optimum distance between the space terminals and the number of segments are determined as follows. By making the distance between the space partial terminals closer to a value larger than L _max (T) with a sub-micrometer, the working material flow can be further increased as described below by taking the power generation operation of FIG. 10 as a specific example.
1) When the distance between the surface of the spire in the space portion terminal to the surface of the counter terminal exceeds L _max (T) , heat transfer due to phonons in this space portion can be almost ignored. This L _max (T) is related to the force between atoms constituting the spire surface and the counter terminal, and can be obtained from the actual measurement range of the distance between the atomic force microscope and the measurement surface. L _max (T) can be corrected by taking into account thermal expansion and thermal fluctuations of the heat source, particularly quantum fluctuations at low temperatures.
2) The enhanced electric field strength in the vicinity of the surface of the steeple in the operating space can be approximated by multiplying the potential difference / distance between the counter terminals by the proportionality factor β taking into account curvature. Or it is calculated | required by simulation. The potential difference between the opposite terminals is influenced by the electromotive force of the thermoelectric material at both ends of the space portion.
3) The amount of movement of the working substance due to thermal excitation of the working substance, quantum fluctuations at low temperatures, and tunnel transmission depends on the working substance release area and direction . In the injected terminal, the state density of the working substance in the bulk of the thermoelectric material into which the working substance is injected changes depending on the direction of movement of the working substance, and as a result, the microscopic electric conductivity and thermal conductivity are affected. give. By making the spiers to the spiers a thin line, these physical property values change and the figure of merit improves. The space shape and the distance between the space portion terminals are optimized so that the working material receiving end face of the space portion satisfies the above-mentioned 2, and the working material flow of the thermoelectric material is brought close to the working material flow. Such a device enables smooth and efficient space movement of the working substance.
4) When a working material flow exceeding the bulk of the thermoelectric material cannot be obtained with one spire, the working material flow can be increased by arranging a plurality of spires as shown in FIG. When the plurality of spires are dense on the surface of the electron emission terminal, the effect of β of 2 is greatly reduced. The work material flow by field electron emission is optimized including the spire density on the surface of the electron emission terminal so that it is greater than or equal to the work material flow of the thermoelectric material at both ends before being divided. In this way, an appropriate distance between the space partial terminals is determined.
Due to the wide temperature difference, the working material flow of the thermoelectric material at both ends before being divided becomes greater than the working material flow of the thermoelectric material at the both ends, or the working material flow due to field electron emission due to the enhanced electric field strength in the space part is the working material of the thermoelectric material bulk If optimization including the spire density on the surface of the electron emission terminal can be performed so that the flow rate is increased or as close as possible, the above ideas 1 to 4 are applied to other space portions. As a result, an additional loss other than the radiation emission energy loss due to the temperature difference between the opposite terminals can be greatly reduced by the optimized space portion including the shape of one or more electrode terminal surfaces. When there is a power generation operation in which the temperature difference between the high temperature part and the low temperature part is narrow, the distance between the space partial terminals cannot be optimized. In this case, the connected space part of FIG. 6 is used. When cooling, apply the necessary voltage and current. If manufactured as described above, even if the performance index of the thermoelectric material is the highest, the performance index of the heat conversion element is greatly improved. Moreover, since the cooling operation is a reversible process of the power generation operation, the efficiency of the heat conversion element manufactured in this way is greatly improved even in the cooling operation.

As shown in FIG. 9, instead of moving the thermoelectric materials 90 and 91 or the thermoelectric material and the terminal , the working substance is less likely to be scattered between the thermoelectric materials 90, and moreover from the emission area of the spire on the opposite end face 91 that releases the working substance. The actuator arranged in 95 helps the fine working substance 94 having a large shape similar to or surrounding the fine moving substance 94 to move parallel to the working material discharge surface. By superimposing alternating current at the start of operation, the space portion 92 or the space 93 between the surface 94 driven by the actuator and the electrode surface 90 serves as a capacitor, so that the voltage applied to the space portion can be made high. . As a result, the high voltage can be used as a trigger for the initial action. Further, by using multiple stages, the voltage applied to the target space portion during operation can be made high by using CR oscillation or CL oscillation.

  By constructing a cue on the working substance discharge surface or the working substance receiving surface, it becomes easy to produce a spire structure. FIG. 11 shows an example in which claim 7 is applied to the thermoelectric conversion element according to claim 1. By providing a cue portion 115 at the time of manufacture between a thermoelectric material having a work substance discharge terminal surface or a good work substance conductor 111 and the work substance discharge terminal 113, the spire structure is easily manufactured. A submicrometer order cue portion can be provided on the nanometer order discharge terminal. Alternatively, the amount of movement of the efficiency material flow can be increased by providing a cue portion which is a good conductor for the work material on the work material receiving surface.
  FIG. 12 shows an example in which claim 7 is applied to the thermoelectric conversion element according to claim 2. By providing at least one of the clue portions 124 having a shape larger in the direction of the working substance flow than 123 at the joint portion connecting the thermoelectric material or good working substance conductors 120 and 121 and the bridging material 123 in which the working substance easily flows, the performance can be improved. Aim for improvement.
  The cue portions 115, 124, 125 are not primarily responsible for the structure but may be responsible for controlling the working material flow. The quality can be improved by making the work substance difficult to be scattered at the cue portion. Further, the flow of the work substance and the heat can be controlled by coating the cue part without changing the ease of scattering of the work substance in the cue part itself. Alternatively, the working substance flow can be increased by connecting the working substance receiving terminal surface 113 or the working substance good conductor bridging member 123 directly to the thermoelectric material or working substance good conductor inside the clue part.

  The above description of maximizing the figure of merit of thermoelectric materials and optimized π-type modules and system embodiments in accordance with the principles of the present invention provides examples and explanations for optimizing thermoelectric materials, π-type modules and systems. The scope of the present invention is disclosed, even if it is exhaustive. It is not limited to the stem embodiment itself. Modifications and variations are possible in accordance with the above teachings, or variations and modifications can be obtained from implementations of the various system embodiments of the present invention. As is apparent, there are numerous implementations in providing a method, π-type module and / or system for realizing a thermal conversion element from a thermoelectric material having a space portion or a connected space portion according to the claimed invention. A form may be employed.

  Any actuators, π-type modules and systems used to describe this application, unless otherwise noted, should not be construed as critical or essential to the invention.

The figure of the space part containing the spire terminal of a thermoelectric conversion element. The figure of the space part containing the spire terminal of a thermoelectric conversion element, and the terminal surrounding it. The figure of the space part which has two or more spire structures of a thermoelectric conversion element. Column structure diagram with a thin cross-sectional area. (A) is a cylinder. (B) is a hollow cylinder. (C) is a rectangular parallelepiped. The thickness sectional drawing of the bridge | crosslinking member which has a layered structure. (A) is a cylinder. (B) is a rectangular parallelepiped. The figure of the space part to which the thermoelectric conversion element was connected. The figure of the connected space part which has a some bridge | crosslinking member with a thermoelectric conversion element. The figure of the space part of a thermoelectric conversion element. The figure of the space part with the work physical distribution which operate | moves with the actuator which has a shape similar to a work substance discharge | release end surface. The figure of the space part segmented into the multistage of the thermoelectric conversion element. The figure of the space part containing the spire terminal which has a cue part of a thermoelectric conversion element. The figure of the connected space part with the clue part of a thermoelectric conversion element.

10 Thermoelectric material or working substance good conductor with working substance receiving terminal surface 11 Thermoelectric material or working substance good conductor with working substance discharging terminal surface 12 Space 13 Spire surface of working substance discharging terminal 14 Working substance receiving terminal surface 20 Working substance receiving terminal surface Thermoelectric material or working substance good conductor 21 having a working substance discharge terminal surface Thermoelectric material or working substance good conductor 22 Space 23 Spire surface 24 of working substance discharge terminal Working substance receiving terminal surface 30, 31, 32 Spire structure 60 Thermoelectric material 61 Thermoelectric Good material or working substance conductor 62 Space 63 Bridging member 70 which is a working substance good conductor Thermoelectric material or working substance good conductor 71 having a working substance receiving terminal surface Thermoelectric material or working substance good conductor 72 having a working substance discharge terminal surface Space 73 Multiple working substances Good conductor bridging member 80 Heat with work substance receiving terminal surface Good material or working substance conductor 81 Thermoelectric material or working substance good conductor 82 having working substance discharge terminal surface Space 90, 91 Thermoelectric material or working substance good conductor 92 space 93 Space 94 between the surface having a similar shape and the terminal surface Surface 95 having a similar shape and a material 100, 101, 102 for allowing the working substance to flow between the surface having the similar shape and the terminal surface, or a segment 110 of a good conductor of the working substance, or a thermoelectric material having a working substance receiving terminal surface or Working material good conductor 111 Thermoelectric material having working substance discharge terminal surface or working substance good conductor 112 space 113 Working substance discharge terminal spire surface 114 Working substance receiving terminal surface 115 Cue part 120 Thermoelectric material 121 Thermoelectric material or working substance good conductor 122 Space 123 Work Material good conductor bridging member 124, 125

Claims (8)

One or more spaces between the end of the thermoelectric material and the surface of the material facing the thermoelectric material or in the thermoelectric material portion constituting the thermoelectric material, which prevent the flow of the heat flow or working substance flow , and the thermoelectric material in contact with these spaces The flow rate of the work substance is equal to or greater than that, but the heat transfer other than that caused by the work substance is almost negligible, and the electric field charge particles , magnetic field charge particles, Josephson junction or concentration diffusion field By including a space part that is easy to release the external working substance particles included , there is no space part to reduce the thermal conductivity or to reduce the damage due to thermal stress or the diffusion of material ions, Or the thermoelectric conversion element characterized by using the heat | fever generate | occur | produced by the movement to the edge part of a working substance. In thermoelectric material part comprising between to the thermoelectric material of the end portion and the therewith confronting the material to the surface of the thermoelectric material comprises one or more spaces are spread prevent the transferred heat flow to the working substance stream most of these By bridging at least one space with one or more fine wires, there is a working substance flow rate equal to or higher than that of the thermoelectric material in contact with this bridging space , but the heat transfer other than that caused by the working substance causes phonon scattering. Thermoelectric conversion characterized in that it is longer than the distance that can be reduced by the length of the wire, and has reduced thermal conductivity or reduced damage due to thermal stress or diffusion of material ions compared to the case where they are joined together without any space. element. Claim 1, in the thermoelectric conversion element according to claim 2, wherein, with these in order to have a space provided with the electromagnetic wave source or radiation source to at least one spatial vicinity of the interface, such as a thermoelectric material, a space provided these ray source A thermoelectric conversion element having a current amount equal to or greater than that of a thermoelectric material in contact with the thermoelectric material, and having a space portion or a bridged space portion and having a reduced thermal conductivity as compared to a case where they are joined to each other. The surface in contact with the space portion or the space portion cross-linked with the thermoelectric conversion element according to claim 1, claim 2, or claim 3 is coated or joined with a conductive material to prevent local charging or retention of a working substance. The thermoelectric conversion element characterized by the above-mentioned. By applying a coating or a material to the surface in contact with the space portion or the bridged space portion with the thermoelectric conversion element according to claim 1 or claim 3 , the energy state of the work material on the surface is changed, and a large current or work material flow is generated. A thermoelectric conversion element characterized by being hardly deteriorated even when flowing. A segment element using a thermoelectric conversion element according to claim 1, claim 2, claim 3, claim 4, or claim 5 or a heat conversion element having a movable portion in a space portion, which is easy to design. A thermoelectric conversion module and a thermoelectric conversion system incorporating them. A direction perpendicular to the direction in which the working substance flow is transmitted to a part extending from a direction that is not a space part to a part having a shape that is easy to release the working substance according to claim 1, or a part that joins the thin line according to claim 2 A thermoelectric conversion element comprising a cue portion having a shape that allows easy release of the external work particles and a protrusion or fine wire larger than the fine wire. The thermoelectric conversion element according to claim 1, claim 2, claim 3, claim 4, claim 5, and claim 7, and the thermoelectric conversion system incorporating them.

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