JP2014011898A - Power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generating system which can generate electricity with excellent efficiency and achieve space saving.SOLUTION: A power generating system 1 includes a heat source 2 of which temperature varies up and down with time, a first device 3 which is electrically polarized by temperature changes of the heat source 2, and a second device 4 for taking out generated power from the first device 3. The second device 4 includes a first electrode 8 and a second electrode 9 having polarities different from each other, and the first electrode 8 includes two outer electrodes 21 which are arranged oppositely so as to sandwich the third device 3 from outside and are electrically connected to one another, and the second electrode 9 includes an inner electrode 24 placed in the first device 3 between two outer electrodes 21.

Description

  The present invention relates to a power generation system, and more particularly to a power generation system mounted on a vehicle such as an automobile.

  Conventionally, in internal combustion engines such as automobile engines, heat exchangers such as boilers and air conditioning equipment, electric engines such as generators and motors, and various energy utilization devices such as light emitting devices such as lighting, for example, as exhaust heat, light, etc. A lot of thermal energy is released and lost.

  In recent years, from the viewpoint of energy saving, it has been required to recover the released thermal energy and reuse it as an energy source. Specifically, as such a system, for example, a heat source whose temperature rises and falls over time, and a first device that is electrically polarized by a piezo effect, a pyroelectric effect, a Seebeck effect, or the like according to a temperature change of the heat source, In order to extract electric power from the first device, a power generation system including a second device (electrode or the like) that is disposed so as to sandwich the first device has been proposed, and in such a power generation system, It has been proposed that devices and second devices are alternately stacked (see, for example, Patent Document 1).

JP 2011-250675 A

  On the other hand, such a power generation system may require even better power generation performance. Also, when the power generation system is installed in a limited space, for example, in an automobile, space saving is required. May be required.

  An object of the present invention is to provide a power generation system capable of generating power with excellent efficiency and saving space.

  In order to achieve the above object, a power generation system according to the present invention includes a heat source whose temperature rises and falls over time, a first device whose temperature rises and falls over time due to a temperature change of the heat source, and the first device. A second device for extracting power from the first device, the second device comprising a first electrode and a second electrode having different polarities, the first electrode sandwiching the first device from the outside Two outer electrodes disposed opposite each other and electrically connected to each other, and the second electrode includes an inner electrode disposed in the first device between the two outer electrodes. It is characterized by.

  In such a power generation system, the second device is disposed so as to face the first device from the outside, and is disposed between the first electrode including two outer electrodes that are electrically connected to each other and the two outer electrodes. And a second electrode including an inner electrode disposed in the first device.

  Therefore, in such a power generation system, power can be generated by the first device in at least two portions between one outer electrode and the inner electrode and between the other outer electrode and the inner electrode. According to such a power generation system, for example, without providing an inner electrode, two outer electrodes are provided separately from each other, and power generation efficiency is improved as compared with a case where power is generated by the first device only between them. Can do.

  As a result, according to such a power generation system, for example, in the case of a power generation system of the same size, the second device is disposed so as to sandwich the first device, and the second device is disposed in the first device. High output can be obtained as compared with the case where no arrangement is made. Further, even if the power generation system is downsized, the second device can be disposed so as to sandwich the first device, and the same level of output as when the second device is not disposed in the first device can be obtained. Space can be achieved.

  Further, in the power generation system of the present invention, the first electrode is further electrically connected to the outer electrode between the two outer electrodes, and at least one inner electrode disposed in the first device. The second electrode comprises a plurality of the inner electrodes that are electrically connected to each other, and in the first device, the inner electrode of the first electrode, and the inner electrode of the second electrode, Are preferably arranged alternately.

  In such a power generation system, since the inner electrode of the first electrode and the inner electrode of the second electrode are alternately arranged in the first device, the power generation efficiency can be further improved. Therefore, higher output can be obtained and space saving can be achieved.

  According to the power generation system of the present invention, since the power generation efficiency can be improved, higher output can be obtained and space saving can be achieved.

FIG. 1 is a schematic configuration diagram showing an embodiment of a power generation system of the present invention. FIG. 2 is an enlarged schematic configuration diagram showing an embodiment of the first device and the second device used in the power generation system of the present invention. FIG. 3 is a schematic configuration diagram showing an embodiment in which the power generation system of the present invention is mounted on a vehicle. FIG. 4 is an enlarged schematic configuration diagram showing another embodiment of the first device and the second device used in the power generation system of the present invention. 3 is a graph showing temperature conditions in Example 1. 3 is a graph showing the generated voltage obtained in Example 1. 6 is a graph showing temperature conditions in Comparative Example 1. 6 is a graph showing a power generation voltage obtained in Comparative Example 1.

  FIG. 1 is a schematic configuration diagram showing an embodiment of a power generation system of the present invention, and FIG. 2 is an enlarged schematic configuration diagram showing an embodiment of a first device and a second device used in the power generation system of the present invention. .

  In FIG. 1, a power generation system 1 includes a heat source 2 whose temperature rises and falls over time, a first device 3 that is electrically polarized by a temperature change of the heat source 2, and a second device 4 that extracts electric power from the first device 3. It has.

  The heat source 2 is not particularly limited as long as the temperature rises and falls over time, and examples thereof include various energy utilization devices such as an internal combustion engine and a light emitting device.

  An internal combustion engine is a device that outputs power, for example, for a vehicle. For example, a single cylinder type or a multi-cylinder type is adopted, and a multi-cycle type (for example, a 2-cycle type, a 4-cycle type) is used in each cylinder. System, 6-cycle system, etc.) are employed.

  In such an internal combustion engine, pistons are repeatedly moved up and down in each cylinder. For example, in a 4-cycle system, an intake process, a compression process, an explosion process, an exhaust process, and the like are sequentially performed, and fuel is discharged. It is burned and power is output.

  In such an internal combustion engine, in the exhaust process, high-temperature exhaust gas is exhausted through an exhaust gas pipe, heat energy is transmitted using the exhaust gas as a heat medium, and the internal temperature of the exhaust gas pipe rises.

  On the other hand, in the other steps (steps excluding the exhaust step), the amount of exhaust gas in the exhaust gas pipe is reduced, so that the internal temperature of the exhaust gas pipe decreases compared to the exhaust process.

  As described above, the temperature of the internal combustion engine rises in the exhaust process and falls in the intake process, the compression process, and the explosion process, that is, rises and falls over time.

  In particular, since each of the above steps is periodically and sequentially repeated according to the piston cycle, the inside of the exhaust gas pipe of each cylinder in the internal combustion engine is periodically cycled with the repetition cycle of each of the above steps. A temperature change, more specifically, a high temperature state and a low temperature state are periodically repeated.

  When the light emitting device is turned on (emission light), for example, light such as infrared rays and visible light is used as a heat medium, and the temperature rises due to the heat energy. Therefore, the temperature of the light emitting device increases and decreases over time by turning on (emitting) and turning off over time.

  In particular, for example, when the light-emitting device is a light-emitting device (blinking (flashing) type light-emitting device) in which lighting is turned on and off intermittently over time, the light-emitting device is turned on (light-emitting). Due to the thermal energy of the light, a temperature change periodically, more specifically, a high temperature state and a low temperature state are periodically repeated.

  Moreover, as the heat source 2, for example, a plurality of heat sources can be provided, and a temperature change can be caused by switching between the plurality of heat sources.

  More specifically, for example, two heat sources, a low-temperature heat source (such as a coolant) and a high-temperature heat source (eg, a heating material) having a higher temperature than the low-temperature heat source, are prepared as the heat source. A mode in which a low-temperature heat source and a high-temperature heat source are alternately switched is used.

  Thereby, the temperature as a heat source can be raised or lowered with time, and in particular, the temperature can be periodically changed by periodically switching the low-temperature heat source and the high-temperature heat source.

  Although it does not restrict | limit especially as the heat source 2 provided with the several heat source which can be switched, For example, the high temperature air provided with the low temperature air supply system for combustion, the thermal storage heat exchanger, the high temperature gas exhaust system, and the supply / exhaust switching valve Combustion furnace (for example, a high-temperature gas generator described in Republished No. 96-5474), for example, a seawater exchange device (hydrogen storage alloy actuator-type seawater exchange device) using a high-temperature heat source, a low-temperature heat source, and a hydrogen storage alloy Is mentioned.

  As these heat sources 2, the said heat source can be used individually or in combination with 2 or more types.

  The heat source 2 is preferably a heat source whose temperature changes periodically with time.

  The heat source 2 is preferably an internal combustion engine.

  The first device 3 is a device that is electrically polarized in accordance with a temperature change of the heat source 2.

  The electric polarization referred to here is a phenomenon in which a potential difference occurs due to dielectric polarization due to displacement of positive and negative ions due to crystal distortion, such as a piezo effect and / or a phenomenon in which a dielectric constant changes due to a temperature change and a potential difference occurs, such as pyroelectricity. It is defined as a phenomenon in which an electromotive force is generated in a material, such as an effect.

  More specifically, examples of the first device 3 include a device that is electrically polarized by a piezo effect, a device that is electrically polarized by a pyroelectric effect, and the like.

  The piezo effect is an effect (phenomenon) in which when a stress or strain is applied, it is electrically polarized according to the magnitude of the stress or strain.

  The first device 3 that is electrically polarized by the piezo effect is not particularly limited, and a known piezo element (piezoelectric element) can be used.

  When a piezo element is used as the first device 3, the piezo element, for example, receives and transfers heat from the heat source 2 in a state where its periphery is fixed by a fixing member and volume expansion is suppressed, and / or Arranged to be cooled.

  The fixing member is not particularly limited, and for example, a second device 4 (for example, an electrode) described later can be used.

  In such a case, the piezo element is heated or cooled (possibly via a heat medium (exhaust gas, light, etc.) as described above) due to a change in temperature of the heat source 2 with time, thereby expanding. Or shrink.

  At this time, since the volume expansion of the piezo element is suppressed by the fixing member, the piezo element is pressed by the fixing member and is electrically polarized by the piezo effect (piezoelectric effect) or phase transformation near the Curie point. . Thereby, as will be described in detail later, power is extracted from the piezo element via the second device 4.

  In addition, such a piezo element is normally maintained in a heated state or a cooled state, and when its temperature becomes constant (that is, a constant volume), the electric polarization is neutralized, and then cooled or heated, Again, it is electrically polarized.

  Therefore, as described above, when the temperature of the heat source 2 periodically changes and the high temperature state and the low temperature state are periodically repeated, the piezo element is periodically heated and cooled. Electrical polarization and its neutralization are repeated periodically.

  As a result, electric power is extracted as a waveform (for example, alternating current, pulsating flow, etc.) that varies periodically by the second device 4 described later.

  The pyroelectric effect is, for example, an effect (phenomenon) in which the insulator is electrically polarized in accordance with a change in temperature when the insulator (dielectric) is heated and cooled, and includes the first effect and the second effect. It is out.

  The first effect is an effect in which, when the insulator is heated and cooled, it spontaneously polarizes due to the temperature change and generates a charge on the surface of the insulator.

  In addition, the second effect is an effect that pressure deformation occurs in the crystal structure due to temperature changes during heating and cooling of the insulator, and piezoelectric polarization occurs due to stress or strain applied to the crystal structure (piezo effect, piezoelectric effect). ).

  The device that is electrically polarized by such a pyroelectric effect is not particularly limited, and a known pyroelectric element can be used.

  When a pyroelectric element is used as the first device 3, the pyroelectric element is disposed so as to transfer heat of the heat source 2 and to be heated and / or cooled.

  In such a case, the pyroelectric element is heated or cooled (possibly via a heat medium (exhaust gas, light, etc.) described above) due to a change in temperature of the heat source 2 with time, and the pyroelectric effect (first The electric polarization is caused by the first effect and the second effect. Thereby, although mentioned later in detail, electric power is taken out from the pyroelectric element via the second device 4.

  Also, such pyroelectric elements are usually maintained in a heated state or a cooled state, and when the temperature becomes constant, the electric polarization is neutralized, and then cooled or heated again to be electrically polarized again. .

  Therefore, when the temperature of the heat source 2 is periodically changed as described above and the high temperature state and the low temperature state are periodically repeated, the pyroelectric element is periodically heated and cooled. The electrical polarization of the element and its neutralization are repeated periodically.

  As a result, electric power is extracted as a waveform (for example, alternating current, pulsating flow, etc.) that varies periodically by the second device 4 described later.

  These first devices 3 can be used alone or in combination of two or more.

Specifically, as described above, the first device 3 is a known pyroelectric element (for example, BaTiO ₃ , CaTiO ₃ , (CaBi) TiO ₃ , BaNd ₂ Ti ₅ O ₁₄ , BaSm ₂ Ti _4. O ₁₂ , lead zirconate titanate (PZT: Pb (Zr, Ti) O ₃ ), etc., known piezo elements (eg, quartz (SiO ₂ ), zinc oxide (ZnO), Rochelle salt (potassium sodium tartrate) _{(KNaC 4 H 4 O 6)} , lead zirconate titanate (PZT: Pb (Zr, Ti ) O 3), lithium niobate (LiNbO _3), lithium tantalate (LiTaO _3), lithium tetraborate _(Li 2 B ₄ O ₇ ), Langasite (La ₃ Ga ₅ SiO ₁₄ ), Aluminum Nitride (AlN), Tourmaline, Poly Vinylidene fluoride (PVDF) or the like can be used.

  The Curie point of the first device 3 is, for example, −77 ° C. or higher, preferably −10 ° C. or higher, for example, 1300 ° C. or lower, preferably 900 ° C. or lower.

  The relative dielectric constant of the first device 3 (insulator (dielectric)) is, for example, 1 or more, preferably 100 or more, more preferably 2000 or more.

  In such a power generation system 1, the higher the relative dielectric constant of the first device 3 (insulator (dielectric)), the higher the energy conversion efficiency and the higher voltage can be taken out. If the relative dielectric constant is less than the above lower limit, the energy conversion efficiency is low, and the voltage of the obtained power may be low.

  The first device 3 (insulator (dielectric)) is electrically polarized by the temperature change of the heat source 2, and the electrical polarization may be any of electronic polarization, ionic polarization, and orientation polarization.

  For example, it is expected that a material that exhibits polarization by orientation polarization (for example, a liquid crystal material) can improve power generation efficiency by changing its molecular structure.

  Such a first device 3 is in contact with the heat source 2 through a second device 4 (described later) as necessary, or a heat medium (exhaust gas, light, etc.) that transfers the heat of the heat source 2. Arranged to be contacted (exposed).

  In FIG. 1, the second device 4 is provided to extract power from the first device 3.

  Such a second device 4 includes an electrode (for example, a copper electrode, a silver electrode, and the like) and a conductive wire connected to the electrode, and is disposed so as to contact the first device 3.

  More specifically, the second device 4 includes a first electrode 8 and a second electrode 9 having different polarities as shown in FIG.

  The first electrode 8 includes two outer electrodes 21, which are arranged to face each other so as to sandwich the first device 3 from the outside (on both sides of the front and back surfaces) and are electrically connected to each other. Yes.

  More specifically, the first electrode 8 is provided so as to extend along the direction orthogonal to the direction in which the first device 3 extends, and from one end of the bottom 22 toward one side in the longitudinal direction. It is formed in a substantially U shape in a sectional view including two wall portions 23. Further, in the first electrode 8, the two wall portions 23 are arranged as outer electrodes 21 so as to contact the front surface and the back surface of the first device 3. Further, the bottom portion 22 electrically connects the two outer electrodes 21 and comes into contact with an end portion on the other side in the longitudinal direction of the first device 3 (the other side with respect to one side where the wall portion 23 is extended). Are arranged.

  The second electrode 9 includes an inner electrode 24 disposed in the first device 3 between the two outer electrodes 21.

  Specifically, the inner electrode 24 is formed so as to extend in parallel with the outer electrode 21 between the two outer electrodes 21 arranged to face each other, and one end portion in the longitudinal direction protrudes from the first device 3, Further, the other end portion in the longitudinal direction is embedded in the first device 3 so as not to contact the bottom portion 22.

  Further, as shown by a broken line in FIG. 2, a conducting wire (second device 4) or the like is electrically connected to the first electrode 8 and the second electrode 9.

  In the power generation system 1 shown in FIG. 1, the second device 4 is electrically connected sequentially to the booster 5, the AC / DC converter (AC-DC converter) 6, and the battery 7.

  In order to generate power with such a power generation system 1, for example, first, the temperature of the heat source 2 is changed over time, preferably periodically, and the first device 3 is heated and heated by the heat source 2. / Or cool. The first device 3 described above is preferably electrically polarized periodically in accordance with such a temperature change.

  Thereafter, the electric power is taken out as a waveform (for example, alternating current, pulsating current, etc.) that periodically fluctuates according to the periodic electric polarization of the first device 3 through the second device 4.

  In such a power generation system 1, the temperature of the heat source 2 is, for example, 200 to 1200 ° C., preferably 700 to 900 ° C. in the high temperature state, and the temperature in the low temperature state is lower than the temperature in the high temperature state. More specifically, for example, 100 to 800 ° C., preferably 200 to 500 ° C., and the temperature difference between the high temperature state and the low temperature state is, for example, 10 to 600 ° C., preferably 20 to 500 ° C. is there.

  Moreover, the repetition period of these high temperature states and low temperature states is, for example, 10 to 400 cycles / second, preferably 30 to 100 cycles / second.

  Then, the electric power extracted by the power generation system 1 in this manner is boosted in a state of a waveform (for example, alternating current, pulsating current) that periodically varies in the booster 5 connected to the second device 4. As the booster 5, a booster capable of boosting AC voltage with excellent efficiency by a simple configuration using, for example, a coil and a capacitor is used.

  Next, the electric power boosted by the booster 5 is converted into a DC voltage by the AC / DC converter 6 and then stored in the battery 7.

  According to such a power generation system 1, since the heat source 2 whose temperature rises and falls with time is used, a fluctuating voltage (for example, an AC voltage) can be extracted, and as a result, a constant voltage (DC voltage) is extracted. Compared to the above, it is possible to store the electric power by boosting with excellent efficiency by a simple configuration.

  In addition, if the heat source 2 is a heat source that periodically changes in temperature, electric power can be extracted as a waveform that varies periodically. As a result, the electric power can be boosted with higher efficiency and stored with a simple configuration. can do.

  In particular, in such a power generation system 1, the second device 4 includes a first electrode 8 including two outer electrodes 21 that are arranged to face each other so as to sandwich the first device 3 from the outside and are electrically connected to each other. A second electrode 9 including an inner electrode 24 disposed in the first device 3 is provided between the two outer electrodes 21.

  Therefore, in such a power generation system 1, power is generated by the first device 3 in at least two portions between the one outer electrode 21 and the inner electrode 24 and between the other outer electrode 21 and the inner electrode 24. Can do. According to such a power generation system 1, for example, without providing the inner electrode 24, the two outer electrodes 21 are provided separately from each other, and the power generation efficiency is higher than in the case where power is generated by the first device 3 only between them. Improvements can be made.

  As a result, according to such a power generation system 1, for example, in the case of the power generation system 1 of the same size, the second device 4 is disposed so as to sandwich the first device 3, and the first device 3 As compared with the case where the second device 4 is not arranged, a higher output can be obtained. Further, even when the power generation system 1 is downsized, the second device 4 is disposed so as to sandwich the first device 3, and the same level of output as in the case where the second device 4 is not disposed in the first device 3 is obtained. And space saving can be achieved.

  FIG. 3 is a schematic configuration diagram showing an embodiment in which the power generation system of the present invention is mounted on a vehicle.

  In FIG. 3, the automobile 10 includes an internal combustion engine 11, a catalyst mounting portion 12, an exhaust pipe 13, a muffler 14, and a discharge pipe 15.

  The internal combustion engine 11 includes an engine 16 and an exhaust manifold 17.

  The engine 16 is a multi-cylinder (4-cylinder type) multi-cycle (4-cycle) engine, and an upstream end portion of a branch pipe 18 (described later) of the exhaust manifold 17 is connected to each cylinder.

  The exhaust manifold 17 is an exhaust manifold provided for converging exhaust gas exhausted from each cylinder of the engine 16, and a plurality of (four) branch pipes 18 (these are connected to each cylinder of the engine 16. 3 are referred to as the branch pipe 18a, the branch pipe 18b, the branch pipe 18c, and the branch pipe 18d in order from the upper side of FIG. 3), and each branch pipe on the downstream side of the branch pipe 18. And an air collecting tube 19 that integrates 18 into one.

  Each branch pipe 18 includes one box-shaped space 20 in the middle of the flow direction. The box-shaped space 20 is a substantially rectangular parallelepiped space interposed so as to communicate with the branch pipe 18, and includes the first device 3 and the second device 4 described above.

  In such an exhaust manifold 17, the upstream end portion of the branch portion 18 is connected to each cylinder of the engine 16, and the downstream end portion of the branch pipe 18 and the upstream end portion of the air collecting pipe 19 are connected to each other. It is connected. Further, the downstream end of the air collecting pipe 19 is connected to the upstream end of the catalyst mounting portion 12.

The catalyst mounting unit 12 includes, for example, a catalyst carrier and a catalyst coated on the carrier, and hydrocarbons (HC), nitrogen oxides (NO _x ) contained in exhaust gas discharged from the internal combustion engine 11, In order to purify harmful components such as carbon monoxide (CO), it is connected to the downstream end of the internal combustion engine 11 (exhaust manifold 17).

  The exhaust pipe 13 is provided to guide the exhaust gas purified in the catalyst mounting portion 12 to the muffler 14. The upstream end is connected to the catalyst mounting portion 12 and the downstream end is the muffler 14. It is connected to the.

  The muffler 14 is provided to silence noise generated in the engine 16 (in particular, an explosion process), and an upstream end thereof is connected to a downstream end of the exhaust pipe 13. The downstream end of the muffler 14 is connected to the upstream end of the discharge pipe 15.

  The exhaust pipe 15 is provided to discharge exhaust gas that has been exhausted from the engine 16 and sequentially passes through the exhaust manifold 17, the catalyst mounting portion 12, the exhaust pipe 13, and the muffler 14, and has been purified and silenced. The upstream end is connected to the downstream end of the muffler 14, and the downstream end is open to the outside air.

  The automobile 10 is equipped with the power generation system 1 as shown by a dotted line in FIG.

  As described above, the power generation system 1 includes the heat source 2, the first device 3, and the second device 4.

  That is, in the power generation system 1, the engine 16 of the internal combustion engine 11 is used as the heat source 2, and the first device 3 and the second device 4 are disposed in the box-shaped space 20 of the branch pipe 18. ing.

  More specifically, in the box-shaped space 20, the outer electrode 21 (bottom 22) side of the second device 4 is disposed on the upstream side in the flow direction, while the inner electrode 24 is disposed on the downstream side in the flow direction. At the same time, the first device 3 is disposed in contact with the second device 4. The first device 3 and the second device 4 are fixed by a fixing member (not shown).

  Further, the power generation system 1 sequentially and electrically supplies a booster 5, an AC / DC converter 6 and a battery 7 sequentially via a second device 4 (for example, a conducting wire) (not shown) as shown in FIG. It is connected.

  In such an automobile 10, by driving the engine 16, the pistons are repeatedly moved up and down in each cylinder, and the intake process, the compression process, the explosion process, and the exhaust process are sequentially performed. Is done.

  More specifically, for example, in two cylinders, that is, a cylinder connected to the branch pipe 18a and a cylinder connected to the branch pipe 18c, the pistons are interlocked to perform the intake process, the compression process, the explosion process, and the exhaust process. , Implemented in phase. As a result, the fuel is combusted and power is output, and high-temperature exhaust gas passes through the branch pipe 18a and the branch pipe 18c in the exhaust process.

  At this time, the heat of the engine 16 is transmitted through the exhaust gas (heat medium), the internal temperatures of the branch pipe 18a and the branch pipe 18c rise in the exhaust process, and other processes (intake process, compression process, explosion) In step (5), it moves up and down with time according to the piston cycle, and the high temperature state and the low temperature state are periodically repeated.

  On the other hand, in the two cylinders, the cylinder connected to the branch pipe 18b and the cylinder connected to the branch pipe 18d at different timings from the two cylinders, the pistons are interlocked, and the intake process, the compression process, The explosion process and the exhaust process are performed in the same phase. As a result, fuel is combusted and power is output, and at a timing different from that of the branch pipe 18a and the branch pipe 18c, high-temperature exhaust gas passes through the branch pipe 18b and the branch pipe 18d in the exhaust process.

  At this time, the heat of the engine 16 is transmitted through the exhaust gas (heat medium), the internal temperatures of the branch pipe 18b and the branch pipe 18d rise in the exhaust process, and other processes (intake process, compression process, explosion) In step (5), it moves up and down with time according to the piston cycle, and the high temperature state and the low temperature state are periodically repeated.

  This periodic temperature change has the same period but a different phase from the periodic temperature changes of the branch pipe 18a and the branch pipe 18c.

  In the power generation system 1, as described above, the first device 3 and the second device 4 are arranged inside each branch pipe 18 (in the box-shaped space 20).

  Therefore, when the exhaust gas discharged from the engine 16 (heat source 2) is introduced into the branch pipe 18 and filled in the box-shaped space 20, the first device 3 and the second device 2 in the box-shaped space 20 are filled. The device 4 is brought into contact with (exposed to) exhaust gas (heat medium) and is heated and / or cooled.

  At this time, as described above, in the box-shaped space 20, the first electrode 8 (particularly, the bottom 22 side) of the second device 4 is disposed on the upstream side in the flow direction, while the second electrode 9 flows. The first device 3 is disposed in contact with the second device 4 while being disposed on the downstream side in the direction.

  Therefore, for example, when the engine 16 (heat source 2) and the heat medium that transfers the heat of the engine 16 are in a high temperature state, the first device 3 starts from the portion that contacts the first electrode 8 (bottom 22). Heating is gradually performed toward the portion in contact with the electrode 9 to be in a high temperature state.

  Further, when the engine 16 (heat source 2) and the heat medium that transfers the heat of the engine 16 are in a low temperature state, the first device 3 is a portion that contacts the first electrode 8 from a portion that contacts the second electrode 9. Then, it is gradually cooled to a low temperature state.

  As described above, the first device 3 is heated and / or cooled by the temperature change of the engine 16 (heat source 2) and the heat medium that transfers the heat of the engine 16 with time.

  And thereby, the 1st device 3 can be periodically made into a high temperature state or a low temperature state, and the effect (for example, piezo element, pyroelectric element, etc.) according to the element (for example, piezo element, pyroelectric element, etc.) , Piezo effect, pyroelectric effect, etc.).

  Therefore, in this power generation system 1, power can be extracted from each first device 3 through the second device 4 as a waveform (for example, alternating current, pulsating current) that periodically varies.

  Further, in this power generation system 1, since the temperature of the branch pipe 18a and the branch pipe 18c and the temperature of the branch pipe 18b and the branch pipe 18d change periodically with the same period and different phases, Can be continuously extracted as a waveform (for example, alternating current, pulsating flow, etc.) that fluctuates automatically.

  Then, after passing through each branch pipe 18, the exhaust gas is supplied to the air collection pipe 19, collected, then supplied to the catalyst mounting section 12, and purified by the catalyst provided in the catalyst mounting section 12. Thereafter, the exhaust gas is supplied to the exhaust pipe 13, silenced in the muffler 14, and then discharged to the outside air through the discharge pipe 15.

  At this time, since the exhaust gas passing through each branch pipe 18 is collected in the air collection pipes 19, the exhaust gas sequentially passes through the air collection pipe 19, the catalyst mounting portion 12, the exhaust pipe 13, the muffler 14, and the exhaust pipe 15. The temperature is smoothed.

  Therefore, the temperature of the air collection pipe 19, the catalyst mounting portion 12, the exhaust pipe 13, the muffler 14 and the exhaust pipe 15 through which such exhaust gas whose temperature has been smoothed normally does not increase or decrease with time, It is constant.

  Therefore, when the air collecting pipe 19, the catalyst mounting part 12, the exhaust pipe 13, the muffler 14 or the exhaust pipe 15 is used as the heat source 2 and the first device 3 is arranged around or inside the heat source 2, it is taken out from the first device 3. The electric power to be generated is small in voltage and constant (DC voltage).

  Therefore, in such a method, there is a problem that the obtained electric power cannot be boosted efficiently with a simple configuration and the power storage efficiency is poor.

  On the other hand, as described above, if the first device 3 described above is arranged in the internal space of the branch pipe 18, the first device 3 is periodically brought into a high temperature state or a low temperature state due to the temperature change of the heat source 2 with time. The first device 3 can be periodically electrically polarized by an effect (for example, piezo effect, pyroelectric effect, etc.) according to the device (for example, piezo element, pyroelectric element, etc.). .

  Therefore, in this power generation system 1, power can be extracted from each first device 3 through the second device 4 as a waveform (for example, alternating current, pulsating current) that periodically varies.

  Thereafter, in this method, for example, as indicated by a dotted line in FIG. 3, the electric power obtained as described above is periodically changed in the booster 5 connected to the second device 4 (for example, alternating current, pulse, etc.). And then the boosted power is converted into a DC voltage by the AC / DC converter 6 and then stored in the battery 7. The electric power stored in the battery 7 can be used as appropriate as the power of the automobile 10 and various electrical components mounted on the automobile 10.

  And according to such a power generation system 1, since the heat source 2 whose temperature rises and falls with time is used, a fluctuating voltage (for example, AC voltage) can be taken out, and as a result, as a constant voltage (DC voltage) Compared with the case of taking out and converting by a DC-DC converter, it is possible to store the electric power by boosting with excellent efficiency.

  In the power generation system 1 described above, the first device 3 is gradually heated from the portion in contact with the first electrode 8 toward the portion in contact with the second electrode 9 to be in a high temperature state. From the portion that contacts the two electrodes 9 to the portion that contacts the first electrode 8, it is gradually cooled to a low temperature state, so that the first device 3 can be electrically polarized more efficiently.

  In particular, in such a power generation system 1, the second device 4 includes a first electrode 8 including two outer electrodes 21 that are arranged to face each other so as to sandwich the first device 3 from the outside and are electrically connected to each other. A second electrode 9 including an inner electrode 24 disposed in the first device 3 is provided between the two outer electrodes 21.

  Therefore, as described above, in such a power generation system 1, in at least two portions between the one external electrode 21 and the inner electrode 24 and between the other outer electrode 21 and the inner electrode 24, the first device 3 can generate electric power. According to such a power generation system 1, for example, without providing the inner electrode 24, the two outer electrodes 21 are provided separately from each other, and the power generation efficiency is higher than in the case where power is generated by the first device 3 only between them. Improvements can be made.

  As a result, according to such a power generation system 1, for example, in the case of the power generation system 1 of the same size, the second device 4 is disposed so as to sandwich the first device 3, and the first device 3 As compared with the case where the second device 4 is not arranged, a higher output can be obtained. Further, even when the power generation system 1 is downsized, the second device 4 is disposed so as to sandwich the first device 3, and the same level of output as in the case where the second device 4 is not disposed in the first device 3 is obtained. And space saving can be achieved.

  In the above description, one first device 3 is arranged with respect to one box-shaped space 20, but although not shown in detail, for example, in the box-shaped space 20, a plurality of first devices 3 are arranged. It can also be arranged. In such a case, the plurality of first devices 3 are aligned and spaced from each other, for example.

  FIG. 4 is an enlarged schematic configuration diagram showing another embodiment of the first device and the second device used in the power generation system of the present invention.

  In the above description, the first electrode 8 includes only two outer electrodes 21, and the second electrode 9 includes only one inner electrode 24. For example, as illustrated in FIG. In addition to the two outer electrodes 21, an inner electrode 24 can be further provided, and the second electrode 9 can include a plurality of inner electrodes 24.

  In the following description, when the inner electrode 24 provided in the first electrode 8 is distinguished from the inner electrode 24 provided in the second electrode 9, the inner electrode 24 provided in the first electrode 8 is referred to as the first inner electrode 24. The inner electrode 24 provided in the second electrode 9 as the electrode 24a is referred to as the second inner electrode 24b.

  In FIG. 4, the first electrode 8 is electrically connected to the outer electrode 21 between the two outer electrodes 21 disposed so as to sandwich the first device from the outside, and between the two outer electrodes 21. And at least one (three in FIG. 4) first inner electrodes 24 a disposed in the first device 3.

  The first inner electrode 24a is located between two outer electrodes 21 (wall portions 23) from the middle portion of the bottom portion 22 of the first electrode 8 (the middle portion in the direction in which the bottom portion 22 extends) toward one side in the longitudinal direction. A plurality (three) are provided so as to protrude, and are arranged in parallel at intervals. Accordingly, the two outer electrodes 21 (wall portion 23) and the plurality (three) of first inner electrodes 24a are electrically connected by the bottom portion 22, and the first electrode 8 is shaped like a comb. Is formed.

  The second electrode 9 includes a bottom portion 25 and a plurality (four in FIG. 4) of second inner electrodes 24b.

  The bottom portion 25 is disposed to face the bottom portion 22 of the first electrode 8 with a space therebetween.

  The second inner electrode 24b is formed so as to protrude from the both end edges of the bottom portion 25 and a middle portion (a middle portion in the direction in which the bottom portion 25 extends) toward the other side in the longitudinal direction.

  More specifically, in FIG. 4, two second inner electrodes 24 b are extended from both end edges of the bottom portion 25 toward the other side in the longitudinal direction. In addition, between the two second inner electrodes 24b, the second inner electrode 24b separately protrudes from the middle portion of the bottom portion 25 (the middle portion in the direction in which the bottom portion 25 extends) toward the other side in the longitudinal direction. In addition, a plurality (two) of the second inner electrodes 24b are arranged in parallel with an interval therebetween.

  Thereby, a plurality (four) of the second inner electrodes 24b are electrically connected by the bottom portion 25, and the second electrode 9 is formed in a comb shape.

  In this embodiment, the first inner electrode 24 a of the first electrode 8 and the second inner electrode 24 b of the second electrode 9 are alternately arranged in the first device 3.

  That is, the second inner electrode 24b of the second electrode 9 is inserted between the outer electrode 21 of the first electrode 9 and the first inner electrode 24a and between the first inner electrodes 24a.

  At this time, the first electrode 8 is arranged so that the one end portion in the longitudinal direction of the outer electrode 21 and the one end portion in the longitudinal direction of the first inner electrode 24 a do not contact the bottom portion 25 of the second electrode 9. Placed. The second electrode 9 is arranged so that the other end portion in the longitudinal direction of the second inner electrode 24 b does not contact the bottom portion 22 of the first electrode 8.

  Although not shown in detail, even in such a power generation system 1, the second device 4 is sequentially electrically connected to the booster 5, the AC / DC converter (AC-DC converter) 6, and the battery 7. ing.

  And when generating electric power with such an electric power generation system 1 provided with the 1st device 3 and the 2nd device 4, the 1st device 3 is first heated and / or cooled by the heat source 2 like the above, After the electric polarization is periodically performed, the electric power is extracted as a waveform that periodically varies through the second device 4. Thereafter, the extracted electric power is boosted in a state of a waveform that fluctuates periodically in a booster 5 connected to the second device 4, converted into a DC voltage in an AC / DC converter 6, and then supplied to a battery 7. Accumulate electricity.

  In such a power generation system 1 as well, the power generation efficiency can be improved as described above, so that a higher output can be obtained and space saving can be achieved.

  In particular, in such a power generation system 1, in the first device 3, the first inner electrode 24a of the first electrode 8 and the second inner electrode 24b of the second electrode 9 are alternately arranged. The power generation efficiency can be further improved. Therefore, higher output can be obtained and space saving can be achieved.

  Hereinafter, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
Bulk-type piezo element (structure: Nb and Sn-added PZT (Nb / Sn / Pb (Zr, Ti) O ₃ ), Curie point 315 ° C., relative dielectric constant: about 2500, product number: H5C, manufactured by Sumitomo Metal Electrodevices ) Was cut into a sheet having a size of 25 mm × 25 mm × 1.2 mm.

  Next, a cut was formed at a position about half the thickness direction (about 0.6 mm from one side) on the side surface of the piezoelectric element, and a silver paste for forming a second electrode (internal electrode) was injected into the cut. . In addition, a silver paste for forming the first electrode (external electrode) is applied so as to wrap both sides and the peripheral side surface (excluding the side surface where the cut is formed) of the piezo element, and then at 300 ° C. by an electric furnace. Heat treated for 1 hour.

  Thereby, the sample provided with the 1st electrode and the 2nd electrode was obtained.

  Then, two conducting wires (lead wires) were prepared, and one side thereof was attached to each electrode, and the other side was connected to a digital multimeter. And the obtained sample was arrange | positioned in the cylinder made from stainless steel.

  A heat gun was used as a heat source, the spray port was directed to the bottom of the first electrode of the sample, and the heat gun and the sample were arranged so that the spray port was 5 cm away from the sample.

  Further, in order to periodically block the hot air from the heat gun, a propeller was disposed between the cylinder on which the sample is disposed and the heat gun.

  And while blowing hot air from the heat gun and rotating the propeller, the sample is periodically irradiated with hot air from the heat gun, the temperature of the sample is raised and lowered over time, and it is electrically polarized. The generated voltage (electric power) was taken out.

  The temperature of the piezo element was measured with an infrared radiation thermometer. And the voltage change of the electric power taken out from the sample was observed with the voltmeter. FIG. 5 shows the temperature condition, and FIG. 6 shows the generated voltage.

Comparative Example 1
Bulk-type piezo element (structure: Nb and Sn-added PZT (Nb / Sn / Pb (Zr, Ti) O ₃ ), Curie point 315 ° C., relative dielectric constant: about 2500, product number: H5C, manufactured by Sumitomo Metal Electrodevices ) Was cut into a sheet having a size of 25 mm × 25 mm × 1.2 mm.

  Next, a silver paste was applied to both sides of the piezo element so as to have a size of 20 mm × 20 mm × 0.1 mm, and heat-treated at 300 ° C. for 1 hour in an electric furnace.

  As a result, a sample provided with only two outer electrodes that were provided separately from each other and were not connected by the bottom or the like was obtained.

  Then, two conducting wires (lead wires) were prepared, and one side thereof was attached to each electrode, and the other side was connected to a digital multimeter. And the obtained sample was arrange | positioned in the cylinder made from stainless steel.

  Then, in the same manner as in Example 1, the temperature of the sample was raised and lowered over time and electrically polarized, and the generated voltage (electric power) was taken out through the electrode and the conductive wire.

The temperature of the piezo element was measured with an infrared radiation thermometer. And the voltage change of the electric power taken out from the sample was observed with the voltmeter. FIG. 7 shows the temperature condition, and FIG. 8 shows the generated voltage.
(Discussion)
According to Example 1 using the sample including the outer electrode and the inner electrode, it was confirmed that the power generation can be efficiently performed as compared with Comparative Example 1 using the sample including only the outer electrode.

DESCRIPTION OF SYMBOLS 1 Power generation system 2 Heat source 3 1st device 4 2nd device 5 Booster 6 AC / DC converter 7 Battery 8 1st electrode 9 2nd electrode 21 Outer electrode 24 Inner electrode

Claims (2)

A heat source whose temperature rises and falls over time;
A first device in which the temperature is increased and decreased over time due to a temperature change of the heat source and is electrically polarized;
A second device for extracting power from the first device;
The second device is:
A first electrode and a second electrode having different polarities,
The first electrode is
Two outer electrodes disposed oppositely to sandwich the first device from the outside and electrically connected to each other;
The second electrode is
An electric power generation system comprising an inner electrode disposed in the first device between two outer electrodes. The first electrode further comprises at least one inner electrode disposed in the first device electrically connected to the outer electrode between two outer electrodes,
The second electrode includes a plurality of the inner electrodes that are electrically connected to each other,
2. The power generation system according to claim 1, wherein the inner electrode of the first electrode and the inner electrode of the second electrode are alternately arranged in the first device.

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