JP2004172481A - Thermoelectric conversion unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoelectric conversion unit which can inexpensively and stably generate electric power, while maintaining power generating efficiency in initial power generation even after the conversion unit is used repeatedly and for a long time. <P>SOLUTION: The thermoelectric conversion unit 10 comprises a thermoelectric conversion means 14 for taking out a generated electromotive force while performing thermoelectric conversion by a thermoelectric conversion mechanism 13 which has one or more p-type thermoelectric conversion elements 11 and one or more n-type thermoelectric conversion elements 12, and a sealing container 15 for storing and sealing the thermoelectric conversion means 14. Humidity in the sealing container 15 is maintained to the minimum. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power generation device that obtains electromotive force from heat, and more particularly to a thermoelectric conversion unit including a thermoelectric conversion element that obtains electromotive force from heat using the Seebeck effect.
[0002]
[Prior art]
The use form of the thermoelectric conversion element is roughly classified into two. One use form is a use for a local cooling system or a heating system using a Peltier effect in which cooling or heat release is caused by a direct current flowing through a thermoelectric conversion element. The other mode of use is as a power generation device to which a thermoelectric conversion element is applied with a thermoelectric conversion by the Seebeck effect of generating an electromotive force by giving a temperature difference to the thermoelectric conversion element.
[0003]
FIG. 12 shows a thermoelectric conversion unit configured using thermoelectric conversion elements.
[0004]
The thermoelectric conversion unit 1 shown in FIG. 12 includes a p-type semiconductor 2 and an n-type semiconductor 3, and an electrode portion 4a which is joined to one of the upper and lower surfaces of the p-type semiconductor 2 and takes out electricity from the p-type semiconductor 2. , An electrode portion 4b joined to one of the upper and lower surfaces of the n-type semiconductor 3 to take out electricity from the n-type semiconductor 3, and opposing the electrode portions 4a and 4b in the p-type semiconductor 2 and the n-type semiconductor 3. It has a connection electrode 5 connected to the other of the upper and lower surfaces, and a protective insulator 6 that covers and protects the electrode portions 4a and 4b and the connection electrode 5, and is formed by closing a gap between the protective insulators 6 with a resin 7. Is done.
[0005]
The thermoelectric conversion unit 1 supplies heat energy by bringing a low-temperature heat source into contact with the surfaces on the side of the electric extraction electrodes 4a and 4b and a high-temperature heat source on the surface opposite to the surface to which the electrode extraction electrodes 4a and 4b are joined. Thus, an electromotive force corresponding to the temperature difference between the low-temperature heat source and the high-temperature heat source, that is, electric energy is obtained. The electromotive force obtained by the thermoelectric conversion can be extracted from the electrode portions 4a and 4b.
[0006]
The thermoelectric conversion unit 1 can directly convert heat energy from two heat sources having a temperature difference into electric energy, and can be a low environmental load type power supply device with little load on the environment. Such a thermoelectric conversion unit 1 is described in, for example, JP-A-2001-102644 (see Patent Document 1).
[0007]
In addition to the thermoelectric conversion unit 1, attention has been paid to a next-generation low environmental load type power supply device such as a solar power generation system using a solar cell and a fuel cell system using hydrogen.
[0008]
[Patent Document 1]
JP 2001-102644 A
[0009]
[Problems to be solved by the invention]
However, when the thermoelectric conversion unit 1 is used repeatedly and continuously for a long time, there is a problem that the power generation efficiency is reduced as the number of times of use and the number of days of use are increased as compared with the time of the first power generation.
[0010]
Further, since the solar power generation system, which is another low environmental load type power supply device, is affected by the sunshine conditions, the operation rate of the solar power generation system is generally low, and there is a problem that the power generation amount fluctuates. In the photovoltaic power generation system, it is necessary to install a power supply unit outside for stable power supply. On the other hand, fuel cells have a problem that the cost of power generation is high because the price of hydrogen, which is a fuel required for power generation, is high.
[0011]
The present invention has been made in consideration of the above circumstances, and has as its object to provide a thermoelectric conversion unit that can maintain power generation efficiency at the time of first power generation even when used repeatedly and for a long time.
[0012]
Further, another object of the present invention is to provide a low-environmental load type power supply device capable of supplying power stably without an external power supply by stable power generation and capable of supplying power at a low power generation cost. To provide a thermoelectric conversion unit.
[0013]
Still another object of the present invention is to provide a thermoelectric conversion unit that can operate while reducing power consumption or generating power using a difference in ambient temperature without supplying power from the outside.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a thermoelectric conversion unit according to the present invention has at least one p-type thermoelectric conversion element and at least one n-type thermoelectric conversion element. Mechanism, a connection conductor for electrically connecting the plurality of thermoelectric conversion elements so as to extract an electromotive force generated by the thermoelectric conversion elements of the thermoelectric conversion mechanism as one power supply device, and a thermoelectric conversion unit joined by the connection conductor An electrode having a power supply terminal for extracting an electromotive force generated by the thermoelectric conversion mechanism from thermoelectric conversion elements located at both ends of the mechanism, and formed by joining the connection conductor and the electrode and the thermoelectric conversion element with a bonding material. A thermoelectric converter is provided, and a hermetically sealed container that stores and seals the thermoelectric converter is provided, and the humidity in the hermetically sealed container is kept to a minimum. It should be noted that the extremely low humidity in the closed container means a very low humidity that can maintain a power generation amount of 90% or more with respect to the initial power generation amount even in the case of a large number of times such as 80 or more times of power generation repetition.
[0015]
In the thermoelectric conversion unit according to the present invention, as described in claim 2, the closed container material is a non-conductive material, and is formed of, for example, an organic material such as acrylic or an inorganic material such as alumina. Features.
[0016]
Further, the thermoelectric conversion unit according to the present invention is characterized in that, as described in claim 3, the humidity in the sealed container is within 1%.
[0017]
Further, in the thermoelectric conversion unit according to the present invention, as described in claim 4, the atmosphere in the sealed container is a reduced pressure atmosphere, nitrogen (N ₂ A) it is selected from at least one of an atmosphere and an inert gas atmosphere.
[0018]
Furthermore, the thermoelectric conversion unit according to the present invention is characterized in that the pressure in the closed container is 9 kPa to 110 kPa, as described in claim 5.
[0019]
On the other hand, in the thermoelectric conversion unit according to the present invention, the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism include bismuth (Bi) and tellurium (Te). As a main component.
[0020]
In the thermoelectric conversion unit according to the present invention, the porosity of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism is 10% or more and 60% or more. It is characterized by the following.
[0021]
Furthermore, the thermoelectric conversion unit according to the present invention is characterized in that, as described in claim 8, the bonding material is a low melting point bonding material that melts at a temperature lower than the melting point of tin (Sn).
[0022]
Furthermore, in the thermoelectric conversion unit according to the present invention, as described in claim 9, the bonding material used as the bonding material is a low melting point bonding material that melts at a temperature lower than the melting point of tin (Sn). Low melting point bonding materials include tin (Sn) / antimony (Sb) -based materials, aluminum (Al) -based materials, copper (Cu) / lead (Pb) alloy-based materials, cadmium (Cd) -based materials, and copper (Cu) · It is characterized by being composed of at least one selected from a cadmium (Cd) -based material, an alkali-cured lead-based material, a zinc (Zn) -based material, and a sintered oil-containing material.
[0023]
On the other hand, in the thermoelectric conversion unit according to the present invention, the bonding material used as the bonding material is a low melting point bonding material that melts at a temperature lower than the melting point of tin (Sn). The thickness of the melting point bonding material is 2 mm or less.
[0024]
In the thermoelectric conversion unit according to the present invention, the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism include an inorganic material in a structure. It is characterized by having.
[0025]
Furthermore, in the thermoelectric conversion unit according to the present invention, as described in claim 12, the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism include an inorganic material in the structure. The ratio of the inorganic material is not less than 10 vol% and not more than 50 vol%.
[0026]
Furthermore, in the thermoelectric conversion unit according to the present invention, as described in claim 13, the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism contain an inorganic material in the structure. Wherein the inorganic material is quartz, alumina, mullite, titania, or zirconia.
[0027]
Such a thermoelectric conversion unit can maintain the power generation efficiency at the time of the initial power generation even when it is used repeatedly and for a long time, and can provide a stable power supply without an external power supply by stable power generation, and is inexpensive. Electricity can be supplied at a low power generation cost.
[0028]
The thermoelectric conversion unit according to the present invention, as described in claim 14, has a thermoelectric conversion mechanism having at least one each of a p-type thermoelectric conversion element and an n-type thermoelectric conversion element, and the thermoelectric conversion mechanism has A connection conductor for electrically connecting the plurality of thermoelectric conversion elements so as to extract an electromotive force generated by the thermoelectric conversion element as one power supply device, and thermoelectric conversion elements located at both ends of the thermoelectric conversion mechanism joined by the connection conductors An electrode having a power supply terminal for extracting an electromotive force generated by the thermoelectric conversion mechanism from a thermoelectric conversion unit, the thermoelectric conversion unit formed by joining the connection conductor and the electrode and the thermoelectric conversion element with a joining material, and the thermoelectric conversion unit A closed container that stores and hermetically seals, and keeps the humidity in the closed container to a minimum, and is attached around an electric device that operates by consuming power such as a measuring instrument, The electric power generated is taken out heat energy from the temperature difference between the ambient serial electrical device characterized by being configured to be utilized as a power source of the electrical device.
[0029]
Since such a thermoelectric conversion unit is configured to be able to supply electric power to the electric device due to a temperature difference around the electric device that consumes the electric power, the power supply from the outside is reduced or the power supply from the outside is reduced. It is possible to operate the electric equipment without the need.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a thermoelectric conversion unit according to the present invention will be described with reference to the drawings.
[0031]
[First Embodiment]
FIG. 1 is a schematic configuration diagram of a thermoelectric conversion unit 10 showing an example of the first embodiment of the thermoelectric conversion unit.
[0032]
The thermoelectric conversion unit 10 shown in FIG. 1 has, for example, a thermoelectric conversion mechanism having at least one p-type thermoelectric conversion element 11 and at least one n-type thermoelectric conversion element 12, similarly to the thermoelectric conversion unit 1 shown in FIG. The thermoelectric conversion unit 13 includes a thermoelectric conversion unit 14 configured to take out the generated electromotive force, and a sealed container 15 that stores and closes the thermoelectric conversion unit 14.
[0033]
FIG. 2 is a schematic structural diagram showing details of the thermoelectric conversion means 14.
[0034]
The thermoelectric conversion unit 14 shown in FIG. 2 includes, for example, a thermoelectric conversion unit 13 having two p-type thermoelectric conversion elements 11 and two n-type thermoelectric conversion elements 12, and an individual thermoelectric conversion element. A connection conductor 17 for electrical connection, an electrode 19 having a power supply terminal 18 as an outlet for taking out an electromotive force from the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 electrically connected, 17 and a surface protection insulator 20 for covering and protecting the periphery so as not to directly touch the electrode 19.
[0035]
The p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 included in the thermoelectric conversion means 14 are thermoelectric conversion elements composed of a composition containing Bi (bismuth) -Te (tellurium) as a main component. The plurality of thermoelectric conversion elements included in the thermoelectric conversion means 14 are electrically connected in series by joining with the connection conductor 17 and the joining material 22 so as to function as one power supply device.
[0036]
The end of the thermoelectric conversion element provided in the thermoelectric conversion means 14, for example, in the case of the thermoelectric conversion means 14 shown in FIG. 2, the p-type thermoelectric conversion element 11a on the left end and the n-type thermoelectric conversion element 12b on the right end Electrodes 19a and 19b having power supply terminals 18a and 18b for extracting electromotive force are respectively joined. Then, the thermoelectric conversion means 14 can take out the electromotive force generated in each thermoelectric conversion element in series from the power supply terminals 18a and 18b provided on the electrodes 19a and 19b. Further, the connection conductor 17 and the electrode 19 provided in the thermoelectric conversion means 14 insulate the surface excluding the power supply terminals 18a and 18b so as not to be directly touched with the hand, and also connect the connection conductor 17, the electrode 19 and the electrode 19 from the external impact. In order to protect the thermoelectric conversion mechanism 13, the thermoelectric conversion mechanism 13 is covered with a surface protection insulator 20 and joined with a joining material 22.
[0037]
The thermoelectric conversion unit 10 shown in FIG. 1 stores the thermoelectric conversion means 14 shown in FIG. 2 in a closed container 15, and hermetically closes the power supply terminals 18 a and 18 b outside the closed container 15. Then, the humidity inside the sealed container 15 storing the thermoelectric conversion means 14 is kept to a minimum. It is to be noted that maintaining the humidity in the sealed container 15 to a minimum means that even when the number of times of power generation (hereinafter referred to as the number of times of repetition) is as large as about 80 times, at least 90% of the initial power generation amount. This means maintaining the humidity in the closed container 15 capable of maintaining the above-described power generation amount.
[0038]
The sealed container 15 is a non-conductive material, and is formed of, for example, an organic material such as epoxy, acrylic, and polytetrafluoroethylene and an inorganic material such as alumina.
[0039]
FIG. 3 shows a comparison between the amount of power generated by the thermoelectric conversion unit 10 and the amount of power generated when the humidity is 0, 1, 2, 5, and 10%.
[0040]
The power generation amount shown in FIG. 3 is obtained by maintaining the humidity in the sealed container 15 provided in the thermoelectric conversion unit 10 at 0% and providing the thermoelectric conversion unit 10 with a temperature difference of 50 ° C. for the first power generation amount. As 100, the power generation amount when the humidity and the number of repetitions in the closed container 15 are changed is shown as a relative value to 100.
[0041]
According to FIG. 3, the thermoelectric conversion unit 10 having a humidity higher than 1% has a larger number of repetitions than the case where the humidity in the sealed container 15 included in the thermoelectric conversion unit 10 is maintained at 0% and 1%. Indeed, the amount of power generation is decreasing. Further, the tendency of the decrease in the amount of power generation shows a remarkable decrease in the thermoelectric conversion unit 10 having a higher humidity.
[0042]
When compared at 80 repetitions, the range of humidity at which power generation of 90% or more of the initial power generation is obtained is 0% to 2%, and when the humidity is more than 5% and 10%, the power generation The amount is less than 90% of the initial power generation. Furthermore, when compared at 120 repetitions, the humidity at which power generation of 90% or more of the initial power generation is obtained is 0%, 1%, and when the humidity is more than 2%, 5%, 10%. In this case, the power generation amount is less than 90% of the initial power generation amount. When the humidity in the closed container 15 is 0%, the power generation amount is almost 100% of the initial power generation amount, and when the humidity in the closed container 15 is 1%, the power generation amount is about 96% of the initial power generation amount. % And the amount of power generation does not decrease much.
[0043]
Therefore, it is desirable that the humidity in the sealed container 15 be in the range of 0% to 2% at which a power generation amount of 90% or more of the initial power generation amount can be obtained even when the number of repetitions is 80. Further, a more desirable range of the humidity in the sealed container 15 is 0% to just over 1% at which a power generation amount of 90% or more of the initial power generation amount can be obtained even when the number of repetitions is 120 times. It is within 0% to 1% at which 95% or more of the initial power generation can be obtained.
[0044]
FIG. 4 shows a plurality of thermoelectric conversion elements included in the thermoelectric conversion mechanism 13 shown in FIG. 1, that is, each of the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 shown in FIG. The relationship between the ratio of porosity (hereinafter, referred to as porosity) and the amount of power generated by the thermoelectric conversion unit 10 is shown.
[0045]
The power generation amount shown in FIG. 4 is a p-type power generation amount where the power generation amount generated when the porosity of the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 included in the thermoelectric conversion mechanism 13 is 0% is 100. The amount of power generation when only the porosity of the thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 is changed is shown as a relative value to 100.
[0046]
According to FIG. 4, the power generation amount tends to increase as the porosity in the thermoelectric conversion element increases. However, as the porosity in the thermoelectric conversion element increases, the workability deteriorates, and chipping or the like tends to occur during the production of the thermoelectric conversion element. That is, the yield decreases as the porosity in the thermoelectric conversion element increases. Therefore, the porosity in the thermoelectric conversion element is in a range where deterioration in workability does not cause a significant decrease in yield, and in a range where an increase in power generation of 5% or more with respect to the power generation at a porosity of 0% is observed. A range of 10% to 60% is desirable. Further, a more preferable range of the porosity in the thermoelectric conversion element is 10% or more and less than 50%, and further preferably 10% or more and 45% or less.
[0047]
FIG. 5 shows a thermoelectric conversion device in which inorganic materials such as alumina, mullite, titania, and zirconia are contained in the structure of the p-type thermoelectric conversion device 11 and the n-type thermoelectric conversion device 12 included in the thermoelectric conversion mechanism 13 shown in FIG. A comparison between a thermoelectric conversion unit 10 using an element and a conventional thermoelectric conversion unit such as the thermoelectric conversion unit 1 shown in FIG.
[0048]
The amount of power generation shown in FIG. 5 is 100, with the amount of power generation of the conventional product being 100. In the structure of the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 shown in FIG. The amount of power generation in the case where titania and zirconia are contained at a certain ratio, for example, 20% vol, is shown as a relative value to 100.
[0049]
According to FIG. 5, when the structure of the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 contains alumina, mullite, titania, and zirconia, which are inorganic materials, about 107% of alumina is used. About 122% for mullite, about 112% for titania, and about 116% for zirconia, all of which increase power generation by about 7% to 22% compared to the power generation of conventional products.
[0050]
Although not shown in FIG. 5, even when quartz is used as the inorganic material, an increase in the amount of power generation is recognized as in the case of the inorganic material shown in FIG.
[0051]
In FIG. 6, the structure of the thermoelectric conversion elements of the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 included in the thermoelectric conversion mechanism 13 shown in FIG. The relationship between the content of the inorganic material and the amount of power generation when the content (vol%) of the material is changed is shown.
[0052]
The amount of power generation shown in FIG. 6 is such that the content of alumina in the structure of the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 included in the thermoelectric conversion mechanism 13 is 0 vol%, that is, the p-type thermoelectric conversion element. Assuming that the amount of power generated when alumina is not contained in the structures of the 11 and n-type thermoelectric conversion elements 12 is 100, the alumina contained in the structure of the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 The power generation amount when only the content is changed is shown as a relative value to 100.
[0053]
According to FIG. 6, the power generation amount tends to increase as the alumina content increases. However, when the content of alumina increases, the workability deteriorates, and chipping or the like easily occurs, so that the yield decreases. Therefore, the content of alumina in the thermoelectric conversion element is in a range where deterioration in workability does not cause a significant decrease in yield, and an increase in power generation of 5% or more with respect to the power generation when the alumina content is 0 vol% is recognized. 10 vol% or more and 50 vol% or less are desirable. Further, a more preferable range of the alumina content is 10 vol% to 45 vol%, and a more preferable range is 10 vol% to 40%.
[0054]
The tendency shown in FIG. 6 is the same for the thermoelectric conversion unit 10 configured using a thermoelectric conversion element containing an inorganic material other than alumina, such as quartz, mullite, titania, and zirconia.
[0055]
In FIG. 7, the atmosphere in the sealed container 15 provided in the thermoelectric conversion unit 10 is an air atmosphere, a reduced pressure atmosphere, and a nitrogen (hereinafter, N). ₂ The comparison of the power generation amount in the atmosphere and the inert gas atmosphere is shown.
[0056]
The amount of power generation shown in FIG. 7 is set such that the atmosphere in the closed container 15 shown in FIG. , Only the atmosphere in the sealed container 15 is ₂ The amount of power generation when the atmosphere and the inert gas atmosphere are changed is shown as a relative value to 100.
[0057]
According to FIG. 7, a reduced pressure atmosphere, N ₂ In the case of an atmosphere or an inert gas atmosphere, even if the number of times of power generation is repeated 100 times, the power generation amount hardly decreases, so that the power generation ratio is 100% or more and about 110% to 120%. I have. Therefore, the inside of the sealed container 15 is set to a reduced pressure atmosphere, N ₂ An atmosphere selected from any of an atmosphere and an inert gas atmosphere is desirable.
[0058]
Further, the pressure in the closed container in the reduced pressure atmosphere is desirably 9 kPa to 100 kPa. The more preferable range of the pressure in the closed container in the reduced pressure atmosphere is 9 kPa to 80 kPa, and more preferably 9 kPa to 60 kPa. On the other hand, N ₂ The pressure in the closed container in an atmosphere or an inert gas atmosphere is preferably 9 kPa to 110 kPa. And N ₂ A more desirable range of the pressure in the closed vessel in the atmosphere and the inert gas atmosphere is 30 kPa to 110 kPa, and more preferably 50 kPa to 110 kPa.
[0059]
In the thermoelectric conversion means 14 included in the thermoelectric unit 10 shown in FIG. 8, a bonding material 22 for bonding the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 to the connection conductor 17 and the electrode 19 is the same as a conventional adhesive. (Hereinafter, referred to as a conventional bonding method) and the amount of power generated when a low melting point bonding material, for example, a tin-antimony-based material is bonded to the bonding material 22 by soldering. The low melting point bonding material refers to a material in which tin alone melts in a solid state, that is, a material having a melting point lower than the melting point of tin (232 ° C.).
[0060]
The power generation amount shown in FIG. 8 is a relative value where the power generation amount when the low melting point bonding material is used as the bonding material 22 is set to 100 when the power generation amount by the conventional bonding method is used. According to FIG. 8, the power generation ratio when the low melting point material is used as the bonding material 22 is about 170%, which is about 1% of the thermoelectric conversion unit (referred to as a conventional product in FIG. 8) bonded by the conventional bonding method. It can be seen that it becomes 0.7 times. Therefore, as the bonding material 22 used in the thermoelectric conversion unit 10 shown in FIG. 1, it is more desirable to use a low-melting-point bonding material than a conventionally used adhesive from the viewpoint of an increase in power generation.
[0061]
The low melting point bonding material used as the bonding material 22 is an aluminum (Al) -based material, a copper (Cu) -lead (Pb) alloy-based material, a cadmium ( Cd) -based material, copper (Cu) / cadmium (Cd) -based material, alkali-cured lead-based material, zinc (Zn) -based material, and sintered oil-containing material. A similar effect can be obtained.
[0062]
On the other hand, when deriving the characteristics shown in FIG. 8, the thermoelectric conversion unit 10 in which a low melting point bonding material as the bonding material 22 of the thermoelectric conversion unit 10 was soldered was used. Similar effects can be obtained by joining by welding, welding or brazing other than soldering. Further, the thickness of the low melting point bonding material does not significantly affect the tendency of the increase in the amount of power generation shown in FIG. 8, but is preferably 2 mm or less from the viewpoint of economy.
[0063]
According to the thermoelectric unit of the present embodiment, by maintaining the humidity in the sealed container 15 included in the thermoelectric conversion unit 10 at 0% to 1%, even when the number of repetitions is 100 or more, the power generation of 95% or more of the initial power generation is performed. It is possible to maintain the quantity.
[0064]
In addition, the proportion of pores, the type and proportion of inorganic materials contained in the p-type thermoelectric conversion element 11 and the n-type thermoelectric conversion element 12 used in the thermoelectric conversion means 14 included in the thermoelectric conversion unit 10, and the inside of the closed container 15. By appropriately selecting the atmosphere, the amount of power generation can be increased. Furthermore, the amount of power generation can be increased by using a low-melting-point bonding material as the bonding material 22 for bonding the bonding conductor 17 and the electrode 19 of the thermoelectric conversion means 14 to the thermoelectric conversion mechanism 13 and the protective insulator 20.
[0065]
In the present embodiment, the thermoelectric converter 14 covered with the protective insulator 20 is stored in the closed container 15. However, the thermoelectric converter 14 is not provided with the protective insulator 20. May be stored in the closed container 15. Further, the non-conductive material used for the closed container 15 may be a metal material having a metal surface subjected to a non-conductive treatment such as an insulating coating.
[0066]
[Second embodiment]
9 to 11 show an example of a thermoelectric conversion unit according to the second embodiment.
[0067]
The thermoelectric conversion units 10A to 10C shown in FIGS. 9 to 11 are thermoelectric conversion units each including a heat supply source 25 and a power supply unit 26 having the same mechanism as the thermoelectric conversion unit 10 shown in FIG. The thermoelectric conversion unit differs from the thermoelectric conversion unit 10 shown in FIG. 1 in that a heat supply source 25 for performing thermoelectric conversion is provided. The thermoelectric conversion unit 10A is essentially the same except that it has a heat supply source 25. Therefore, portions that are not substantially different from the thermoelectric conversion unit 10 according to the first embodiment are denoted by the same reference numerals and described. Is omitted.
[0068]
FIG. 9 shows an example of a thermoelectric conversion unit 10A using a water supply pipe as the heat supply source 25.
[0069]
In the thermoelectric conversion unit 10A shown in FIG. 9, a water supply pipe having a device (hereinafter, referred to as an electric device) 29 that operates by consuming power, such as a water meter that requires power supply, as the heat supply source 25 is used. The power supply unit 26 includes a power supply unit 26 and a power supply medium 30 that supplies power from the power supply unit 26 to the electric device 29.
[0070]
The thermoelectric conversion unit 10 </ b> A extracts a heat energy as a heat supply source 25 using a temperature difference around a water pipe having a water meter as the electric device 29. The power supply unit 26 is a thermoelectric conversion unit in which the heat supply source 25 and the power supply unit 26 that generate electric power by performing thermoelectric conversion using the heat energy from the heat supply source 25 are used. The thermoelectric conversion unit 10A shown in FIG. 9 uses the temperature difference from the water temperature, the ground temperature, and the ambient temperature obtained through the water supply pipe as the heat supply source 25, and uses the extracted heat energy as the thermoelectric conversion unit 10A shown in FIG. The thermoelectric conversion is performed by the power supply unit 26 having the same mechanism as described above. The electromotive force generated by the power supply unit 26 provided in the thermoelectric conversion unit 10A performing thermoelectric conversion is configured to be usable as a power supply of a water meter as the electric device 29.
[0071]
FIG. 10 shows an example of a thermoelectric conversion unit 10B as another example of the second embodiment.
[0072]
The thermoelectric conversion unit 10B shown in FIG. 10 includes a gas pipe having a gas flow meter as the electric device 29, a power supply unit 26, and a power supply medium 30. The thermoelectric conversion unit 10B generates power by performing thermoelectric conversion in the power supply unit 26 using the gas temperature obtained through the gas pipe and the temperature difference from the ambient temperature as the heat supply source 25. The power generated by the power supply unit 26 included in the thermoelectric conversion unit 10B illustrated in FIG. 10 is supplied to the gas flow meter as the electric device 29 by the power supply medium 30, and the gas flow meter is driven.
[0073]
Further, FIG. 11 shows an example of a thermoelectric conversion unit 10C as another example of the second embodiment.
[0074]
The thermoelectric conversion unit 10C illustrated in FIG. 11 includes the thermoelectric conversion unit 10A illustrated in FIG. 9 and a battery 35 including a power supply control unit capable of controlling power supply.
[0075]
The thermoelectric conversion unit 10 </ b> C temporarily stores the electromotive force obtained by the thermoelectric conversion in the battery 35 and operates the electric device 29 via the battery 35. The thermoelectric conversion unit 10 </ b> C including the battery 35 supplies a constant amount of power to the water meter as the electric device 29 even when the temperature near the heat supply source 25 changes and the amount of power generation fluctuates and becomes unstable. can do. In addition, since the battery 35 includes the power supply control unit, the generated electricity can be supplied to the water meter as the electric device 29 when necessary.
[0076]
According to the thermoelectric unit of the present embodiment, since the thermoelectric unit includes the heat supply source 25 and the power supply unit 26 that performs thermoelectric conversion, for example, an apparatus including an electric device 29 such as a water pipe having a water meter is used. In the case of the thermoelectric conversion unit 10A serving as the heat supply source 25, the temperature difference around the water supply pipe is taken out as heat energy, and the electric device 29 can be operated with the electric power generated by performing thermoelectric conversion in the electric power supply unit 26. Therefore, an external power supply for operating the electric device 29 is not required.
[0077]
Further, as another embodiment, the thermoelectric conversion unit 10C including the battery 35 including the power supply control means is capable of maintaining a constant amount of power even when the temperature near the heat supply source 25 changes and the amount of power generation is unstable. Can be supplied. Furthermore, by controlling the power supply by the power supply control means, it is possible to supply the electric power generated by the thermoelectric conversion unit 10C to the electric equipment 29 other than the water meter as the electric equipment 29 which is normally used.
[0078]
Although the battery 35 provided in the thermoelectric conversion unit 10C is provided with the power supply control means, it is possible to supply a constant amount of power to the electric device 29 without the power supply control means. is there.
[0079]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the thermoelectric conversion unit which concerns on this invention, even if it uses repeatedly and it uses for a long period of time, the electric power generation amount at the time of the first electric power generation can be maintained, without hardly decreasing the electric power generation amount.
[0080]
In addition, the thermoelectric conversion unit is a low environmental load type power supply device that directly converts heat energy into electric energy, and is capable of generating power stably using a temperature difference around the thermoelectric conversion unit. Further, since the thermal energy to be used can utilize the temperature difference generated in the natural environment, it is possible to supply power with reduced power generation costs.
[0081]
Further, the thermoelectric conversion unit is composed of a thermoelectric conversion unit provided in the thermoelectric conversion unit, which generates electric power by utilizing a temperature difference of the surroundings. If an electric device integrated thermoelectric conversion unit with a conversion unit is formed, the electric device included in the electric device integrated thermoelectric conversion unit can be operated even if there is almost no power supply from outside the thermoelectric conversion unit or no power supply at all Can be configured as possible.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a thermoelectric conversion unit according to the present invention.
FIG. 2 is a schematic configuration diagram of a thermoelectric conversion unit included in the thermoelectric conversion unit according to the present invention.
FIG. 3 is a graph showing the relationship between the number of times of power generation and the power generation ratio in the thermoelectric conversion unit when the thermoelectric conversion is performed by changing the humidity in the sealed container provided in the thermoelectric conversion unit according to the present invention in the range of 0% to 10%. FIG.
FIG. 4 is a correlation diagram showing the relationship between the ratio of the pores in the thermoelectric element and the power generation ratio when the thermoelectric conversion is performed by changing the ratio of the pores in the thermoelectric element included in the thermoelectric conversion unit according to the present invention.
FIG. 5 is an explanatory diagram illustrating the relationship between the type of inorganic material and the power generation ratio when performing thermoelectric conversion while changing the type of inorganic material contained in the thermoelectric conversion element provided in the thermoelectric conversion unit according to the present invention.
FIG. 6 shows the relationship between the content of the inorganic material and the power generation ratio when the thermoelectric conversion is performed by changing the content (vol%) of alumina (inorganic material) contained in the thermoelectric element included in the thermoelectric conversion unit according to the present invention. FIG.
FIG. 7 is an explanatory diagram illustrating the relationship between the atmosphere in the closed vessel provided in the thermoelectric conversion unit and the power generation ratio when the thermoelectric conversion unit according to the present invention performs thermoelectric conversion 100 times.
FIG. 8 is a diagram showing a case where a thermoelectric conversion unit according to the present invention performs thermoelectric conversion, a case where a low melting point alloy material is used for a joint surface between a heat source part and an electrode, and an electrode and an insulator provided in the thermoelectric conversion unit; Explanatory drawing explaining the relationship of the power generation amount ratio in the case of using.
FIG. 9 is an apparatus configuration diagram showing an embodiment of a thermoelectric conversion unit in which the thermoelectric conversion unit according to the present invention is attached to a water pipe and applied as a power supply source to a water meter.
FIG. 10 is an apparatus configuration diagram showing an embodiment of a thermoelectric conversion unit in which a thermoelectric conversion unit according to the present invention is attached to a gas pipe and applied as a power supply source to a gas meter.
FIG. 11 is a diagram illustrating an example of a thermoelectric conversion unit in which a thermoelectric conversion unit according to the present invention is mounted on a water pipe, generated electricity is stored in a battery, and the battery is applied as a power supply source to a water meter. FIG.
FIG. 12 is a schematic diagram of a conventional thermoelectric conversion unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Thermoelectric conversion unit, 11 ... p-type thermoelectric conversion element, 12 ... n-type thermoelectric conversion element, 13 ... thermoelectric conversion mechanism, 14 ... thermoelectric conversion means, 15 ... closed container, 17 ... connection conductor, 18a, 18b ... Power supply terminals, 19a, 19b: electrodes, 20: surface protective insulator, 25: heat supply source, 26: power supply unit, 29: electric equipment, 30, 30a, 30b: power supply medium, 35: battery.

Claims (14)

a thermoelectric conversion mechanism having at least one each of a p-type thermoelectric conversion element and an n-type thermoelectric conversion element; and the plurality of thermoelectric conversion mechanisms for extracting an electromotive force generated by the thermoelectric conversion element of the thermoelectric conversion mechanism as one power supply device. A connection conductor for electrically connecting the thermoelectric conversion elements, and an electrode having a power supply terminal for extracting an electromotive force generated by the thermoelectric conversion mechanism from the thermoelectric conversion elements located at both ends of the thermoelectric conversion mechanism joined by the connection conductor. A thermoelectric conversion unit formed by joining the connection conductor and the electrode and the thermoelectric conversion element with a joining material,
A closed container that stores and closes the thermoelectric conversion unit,
A thermoelectric conversion unit, wherein the humidity in the closed container is kept to a minimum. The thermoelectric conversion unit according to claim 1, wherein the closed container material is a non-conductive material, and is formed of, for example, an organic material such as acrylic or an inorganic material such as alumina. 3. The thermoelectric conversion unit according to claim 1, wherein the humidity in the closed container is within 1%. The atmosphere in the sealed container is reduced pressure atmosphere, nitrogen (N ₂₎ atmosphere and the thermoelectric conversion unit according to claim 1, characterized in that it is selected from at least one inert gas atmosphere. The thermoelectric conversion unit according to claim 1, wherein the pressure in the closed container is 9 kPa to 110 kPa. 2. The thermoelectric conversion unit according to claim 1, wherein the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism contain bismuth (Bi) and tellurium (Te) as main components. 3. 3. The thermoelectric conversion unit according to claim 1, wherein the porosity of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism is 10% or more and 60% or less. 3. The thermoelectric conversion unit according to claim 1, wherein the bonding material is a low melting point bonding material that melts at a temperature lower than a melting point of tin (Sn). 4. The bonding material used as the bonding material is a low melting point bonding material that melts at a temperature lower than the melting point of tin (Sn). The low melting point bonding material is a tin (Sn) / antimony (Sb) -based material, aluminum (Al). ) -Based materials, copper (Cu) / lead (Pb) alloy-based materials, cadmium (Cd) -based materials, copper (Cu) / cadmium (Cd) -based materials, alkali-cured lead-based materials, zinc (Zn) -based materials, The thermoelectric conversion unit according to claim 1, wherein the thermoelectric conversion unit is formed of one or more types selected from oil-containing materials. The bonding material used as the bonding material is a low melting point bonding material that melts at a temperature lower than the melting point of tin (Sn), and the thickness of the low melting point bonding material is 2 mm or less. 2. The thermoelectric conversion unit according to 2. The thermoelectric conversion unit according to claim 1, wherein the p-type thermoelectric conversion element and the n-type thermoelectric conversion element of the thermoelectric conversion mechanism include an inorganic material in a structure. The p-type thermoelectric conversion element and the n-type thermoelectric conversion element included in the thermoelectric conversion mechanism include an inorganic material in a structure, and a ratio of the inorganic material is 10 vol% or more and 50 vol% or less. The thermoelectric conversion unit according to claim 11, wherein The p-type thermoelectric conversion element and the n-type thermoelectric conversion element having the thermoelectric conversion mechanism contain an inorganic material in the structure, and the inorganic material is quartz, alumina, mullite, titania, and zirconia. The thermoelectric conversion unit according to claim 11 or 12, wherein a thermoelectric conversion mechanism having at least one each of a p-type thermoelectric conversion element and an n-type thermoelectric conversion element; and the plurality of thermoelectric conversion mechanisms for extracting an electromotive force generated by the thermoelectric conversion element of the thermoelectric conversion mechanism as one power supply device. A connection conductor for electrically connecting the thermoelectric conversion elements, and an electrode having a power supply terminal for extracting an electromotive force generated by the thermoelectric conversion mechanism from the thermoelectric conversion elements located at both ends of the thermoelectric conversion mechanism joined by the connection conductor. A thermoelectric conversion unit formed by joining the connection conductor and the electrode and the thermoelectric conversion element with a joining material,
A closed container that stores and closes the thermoelectric conversion unit,
Keeping the humidity in the closed container to a minimum, attached to the periphery of electrical equipment that operates with power consumption such as measuring instruments,
A thermoelectric conversion unit wherein power generated by extracting heat energy from a temperature difference around the electric device can be used as a power source of the electric device.

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