JP2013096274A - On-vehicle power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle power generation system in which device damage can be suppressed.SOLUTION: An on-vehicle power generation system 1 comprises: an internal combustion engine 2 including an engine 11 and an exhaust pipe 17; a first device 3 which is disposed within the exhaust pipe 17 and electrically polarized by supplying thereto exhaust gas of which the temperature varies with the passage of time; a second device 4 for taking power out of the first device 3; an afterburn prediction apparatus 5 for predicting the occurrence of afterburn and/or a water spray prediction apparatus 6 for predicting the occurrence of water spray in the first device 3; a flow passage regulation apparatus 7 for changing a flowing direction of exhaust gas flowing toward the first device 3 into a direction avoiding the first device 3; and a control unit 8 for operating the flow passage regulation apparatus 7 when the occurrence of afterburn is predicted by the afterburn prediction apparatus 5 and/or the occurrence of water spray in the first device 3 is predicted by the water spray prediction apparatus 6.

Description

  The present invention relates to an on-vehicle power generation system, and more particularly to an on-vehicle 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 is required to recover the released thermal energy and reuse it as an energy source. As such a method, thermoelectric conversion power generation using a pyroelectric element is known. Yes.

  Specifically, for example, a heating source that increases the temperature of each of the plurality of pyroelectric elements, a cooling source that decreases the temperature of each of the pyroelectric elements, a heating source and a cooling source, and / or a pyroelectric element A method of taking out DC power or AC power from a pyroelectric element by periodically raising and lowering the temperature of the pyroelectric element by a heating source and a cooling source using a power generation device including a moving unit that moves the element, It has been proposed (see, for example, Patent Document 1).

JP-A-11-332266

  On the other hand, as such a power generation method, a power generation device is mounted on a vehicle such as an automobile, for example, a pyroelectric element is disposed in an exhaust pipe from which exhaust gas is exhausted from an internal combustion engine, and the exhaust gas is supplied to a heating source and Use as a cooling source can also be considered.

  In such a case, air and fuel are supplied to the internal combustion engine, and the fuel is combusted to generate exhaust gas. The pyroelectric element is heated and cooled in the exhaust pipe by the exhaust gas.

  However, when the power generator is mounted on the vehicle, depending on the vehicle state, unburned or incompletely burned fuel may be discharged together with the exhaust gas into the exhaust pipe, and the fuel may explode in the exhaust pipe (afterburn).

  When the pyroelectric element is arranged in the exhaust pipe, if an afterburn occurs in the exhaust pipe, the pyroelectric element may be damaged due to the impact or the like.

  In addition, when the power generator is mounted on the vehicle, depending on the vehicle state, water contained in the exhaust gas may be cooled, and condensed water may be generated on the inner wall of the exhaust pipe.

  When the pyroelectric element is arranged in the exhaust pipe, if condensed water is generated on the inner wall of the exhaust pipe, the water may be transported by the exhaust gas and adhere to the pyroelectric element. In such a case, since the pyroelectric element is rapidly cooled, the pyroelectric element may be damaged.

  The objective of this invention is providing the vehicle-mounted electric power generation system which can suppress damage of a device.

  In order to achieve the above object, an in-vehicle power generation system according to the present invention includes an engine, an internal combustion engine including an exhaust pipe for exhausting exhaust gas from the engine, and the exhaust pipe, and the temperature increases and decreases over time. A first device that is electrically polarized by being supplied with exhaust gas, a second device that extracts power from the first device, an afterburn predicting means that predicts the occurrence of afterburn in the exhaust pipe, and / or Or in the exhaust pipe, the flow direction of the exhaust gas flowing toward the first device in a direction avoiding the first device in the exhaust pipe and predicting the generation of water in the first device When the occurrence of afterburn is predicted by the flow direction changing means for changing, and the afterburn predicting means, and / or The when the occurrence of the water of the first device is predicted by the water predicting means, it is characterized in that a control means for actuating said flow direction changing means.

  According to the in-vehicle power generation system of the present invention, control is performed when occurrence of afterburn is predicted by the afterburn prediction means and / or when occurrence of water in the first device is predicted by the moisture prediction means. The flow direction changing means is actuated by the means, and the flow direction of the exhaust gas flowing toward the first device is changed to a direction avoiding the first device.

  According to such an in-vehicle power generation system, when the occurrence of afterburn is predicted, the exhaust gas flows in a direction avoiding the first device. Therefore, it is possible to suppress afterburning in the vicinity of the first device, and it is possible to suppress damage to the first device due to the impact.

  Moreover, according to such an in-vehicle power generation system, when condensed water is generated in the exhaust pipe and generation of water in the first device is predicted, the exhaust gas flows in a direction avoiding the first device. Therefore, it can suppress that water is transported by exhaust gas and adheres to a 1st device, and it can suppress that a 1st device is rapidly cooled with the water and is damaged.

1 is a schematic configuration diagram of one embodiment (first embodiment) of an in-vehicle power generation system of the present invention. It is a principal part schematic block diagram of other embodiment (2nd Embodiment) of the vehicle-mounted electric power generation system of this invention.

1. First Embodiment FIG. 1 is a schematic configuration diagram of an embodiment (first embodiment) of an in-vehicle power generation system of the present invention.

  In FIG. 1, an automobile 10 includes an in-vehicle power generation system 1.

  The in-vehicle power generation system 1 takes out electric power from the internal combustion engine 2, the first device 3 that is electrically polarized by being supplied with exhaust gas that is exhausted from the internal combustion engine 2 and whose temperature rises and falls over time. Second device 4 for the above, afterburn predicting device 5 as an afterburn predicting unit for predicting the occurrence of afterburn, and wetness predicting device as a wetted predicting unit for predicting the occurrence of water in the first device 3 6, a flow path regulating device 7 as a flow direction changing means for changing the flow direction of the exhaust gas, and a control unit 8 as a control means for operating the flow path regulating device 7.

  The internal combustion engine 2 includes an engine 11, an intake pipe 16 for supplying air to the engine 11, an exhaust pipe 17 for exhausting exhaust gas from the engine 11, and fuel supply means for supplying fuel to the engine 11. The fuel supply device 20 is provided.

  The engine 11 is a device that outputs power of a vehicle or the like. For example, a single-cylinder type or a multi-cylinder type (for example, a 2-cylinder type, a 4-cylinder type, or a 6-cylinder type) is adopted. A multi-cycle method (for example, a 2-cycle method, a 4-cycle method, a 6-cycle method, etc.) is employed.

  Hereinafter, the engine 11 in which the 4-cylinder type is adopted and the 4-cycle system is adopted in each cylinder will be described.

  The engine 11 includes a plurality (four) of cylinders 12 arranged in parallel. In FIG. 1, one cylinder 12 is taken out and the other cylinders 12 are omitted.

  Each cylinder 12 includes a piston 13, a combustion chamber 14, an ignition plug (not shown), and the like. The upstream side is connected to the intake pipe 16 and the downstream side is connected to the exhaust pipe 17.

  Each cylinder 12 includes an intake valve 18 at a connection portion connected to the intake pipe 16 and an exhaust valve 19 at a connection portion connected to the exhaust pipe 17.

  The intake valve 18 is provided at a connection portion between the cylinder 12 and the intake pipe 16 so that the cylinder 12 can be opened and closed.

  The exhaust valve 19 is provided at the connecting portion between the cylinder 12 and the exhaust pipe 17 so that the cylinder 12 can be opened and closed.

  Although not shown, the intake valve 18 and the exhaust valve 19 are urged in the closing direction by an elastic force such as a spring. The intake valve 18 and the exhaust valve 19 can open and close the cylinder 12 by, for example, rotation of a camshaft.

  The intake pipe 16 is provided to supply air to the engine 11, and its downstream end is connected to the cylinder 12 of the engine 11 and its upstream end is open to the outside air.

  The intake pipe 16 includes a throttle valve 27. For example, the throttle valve 27 can be opened and closed and the opening thereof can be adjusted in accordance with a driving operation such as depressing an accelerator pedal, and air can be taken into the engine 11 by the opening and closing.

  The exhaust pipe 17 is provided to exhaust the exhaust gas from the engine 11, and its upstream end is connected to the cylinder 12 of the engine 11.

  Further, the exhaust pipe 17 includes a sub exhaust pipe 29.

  The sub-exhaust pipe 29 is a bypass flow path provided for flowing exhaust gas in a direction to avoid the first device 3 (described later), and an upstream end is connected to the upstream side of the first device 3 (described later). At the same time, the downstream end is connected to the downstream side of the first device 3 (described later).

  Further, although not shown in the drawing, a plurality (four) of exhaust pipes 17 connected to a plurality (four) of cylinders 12 are gathered into one on the downstream side of the engine 11 and the first device 3 (described later). The downstream end of the assembled exhaust pipe 17 is open to the outside air. As a result, exhaust gases discharged from the engine 11 can be collected and released to the outside air.

  The fuel supply device 20 includes a fuel tank 21 and a fuel supply pipe 22.

  The fuel tank 21 is a tank that stores fuel (for example, gasoline) supplied to the engine, and is formed of a heat-resistant pressure-resistant container or the like.

  The fuel supply pipe 22 is provided to supply fuel from the fuel tank 21 to the engine 11, and its upstream end is connected to the fuel tank 21 and its downstream end is connected to the fuel injection valve 23. It is connected.

  The fuel injection valve 23 is a valve for adjusting the amount of fuel supplied from the fuel tank 21 to the engine 11 and injecting the fuel to the engine 11, and is provided at the downstream end of the fuel supply pipe 22. It is provided and connected to the upstream side of the intake valve 18 of the intake pipe 16.

  The fuel injection valve 23 is not particularly limited, and a known injection valve can be used.

  Such a fuel injection valve 23 is electrically connected to the engine control unit 28 of the engine 11, and its opening / closing is controlled by the engine control unit 28.

  The engine control unit 28 operates the engine 11 (for example, the rotational speed of the engine 11 detected by a tachometer (not shown), for example, the pressure in the intake pipe 16 downstream of the throttle valve 27 detected by a pressure sensor (not shown)). Etc.), and is composed of a microcomputer including a CPU, a ROM, a RAM, and the like.

  The fuel injection valve 23 is electrically connected to the engine control unit 28, whereby a control signal from the engine control unit 28 can be input to the fuel injection valve 23. Thereby, the engine control unit 28 controls the opening and closing and the opening degree of the fuel injection valve 23, that is, the fuel injection amount (fuel supply amount to the engine 11) by the fuel injection valve 23 in accordance with the operating state of the engine 11. It is possible.

  The first device 3 is a device which is discharged from the internal combustion engine 2 (engine 11) and is electrically polarized by increasing or decreasing the temperature with time by supplying exhaust gas whose temperature increases or decreases with time.

  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 is, for example, in contact with (exposed to) exhaust gas in a state where its periphery is fixed by a fixing member and volume expansion is suppressed. Arranged in the exhaust pipe 17.

  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 by the temperature change of the exhaust gas with time, and thereby expanded or contracted.

  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 exhaust gas periodically changes in temperature 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 in the exhaust pipe 17 so as to be in contact (exposed) with the exhaust gas.

  In such a case, the pyroelectric element is heated or cooled by the temperature change of the exhaust gas with time, and is electrically polarized by the pyroelectric effect (including 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 exhaust gas changes periodically 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.

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 (tourmaline), poly Vinylidene fluoride (PVDF) or the like can be used.

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

  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 an in-vehicle power generation system 1, the higher the relative permittivity of the first device 3 (insulator (dielectric material)), the higher the energy conversion efficiency and the higher voltage the electric power can be extracted. If the relative dielectric constant is less than the lower limit, the energy conversion efficiency may be 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 exhaust gas. The electrical polarization may be any of electronic polarization, ion 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.

  A plurality of such first devices 3 are arranged in the exhaust pipe 17 at intervals, for example, and fixed by the second device 4 (and a fixing member (not shown) provided if necessary). Yes. In FIG. 1, one first device 3 is extracted and shown, and the other first devices 3 are omitted.

  As a result, the first device 3 can contact (expose) the exhaust gas through the second device 4 in the exhaust pipe 17.

  The second device 4 is provided to extract power from the first device 3.

  More specifically, the second device 4 is not particularly limited, but, for example, two electrodes (for example, a copper electrode, a silver electrode, etc.) disposed opposite to each other with the first device 3 interposed therebetween, for example, ., And the like, and are electrically connected to the first device 3.

  In addition, the second device 4 is electrically connected to the battery 9 via a booster (not shown), an AC / DC converter (AC-DC converter) (not shown), etc., if necessary. Yes.

  The afterburn prediction device 5 is a device for predicting the occurrence of afterburn (described later) in the exhaust pipe 17, and is composed of a microcomputer including a CPU, a ROM, a RAM, and the like.

  The afterburn predicting device 5 has a throttle valve 27, a spark plug (not shown), a limiter (not shown), etc., as shown by broken lines in FIG. Are electrically connected to each other, and the occurrence of afterburn (described later) can be predicted.

  The water exposure prediction apparatus 6 is an apparatus for predicting that water adheres to the first device 3 arranged in the exhaust pipe 17 (that is, generation of water exposure of the first device 3), and includes a CPU, It is comprised from the microcomputer provided with ROM, RAM, etc.

  This wetness prediction apparatus 6 includes a temperature sensor 15. The temperature sensor 15 is provided close to or in contact with the exhaust pipe 17 in order to detect the inner wall temperature of the exhaust pipe 17 upstream of the first device 3. For example, a known temperature sensor such as an infrared radiation thermometer or a thermocouple thermometer is used as the temperature sensor 15.

  By measuring the inner wall temperature of the exhaust pipe 17 by the temperature sensor 15, the water-receiving prediction device 6 can predict that condensed water is generated on the inner wall of the exhaust pipe 17, and thereby the first device 3. The occurrence of water exposure can be predicted.

  The flow path regulating device 7 is, for example, a three-way valve that switches between a position where the exhaust gas passes through the exhaust pipe 17 and a position where the exhaust gas passes through the sub exhaust pipe 29 so as to be interposed in the exhaust pipe 17. The exhaust pipe 17 and the auxiliary exhaust pipe 29 are provided at the connection portion between the upstream end portions.

  Such a flow path regulating device 7 can open and close the exhaust pipe 17 and the sub exhaust pipe 29 by switching.

  Specifically, the flow path restriction device 7 opens the exhaust pipe 17 and closes the sub exhaust pipe 29 to flow exhaust gas into the exhaust pipe 17 and supply it to the first device 3; By closing the exhaust pipe 17 and opening the sub exhaust pipe 29, it is possible to switch to a position where exhaust gas can flow into the sub exhaust pipe 29 and the first device 3 can be avoided.

  As described above, the flow path restriction device 7 can change the flow direction of the exhaust gas flowing toward the first device 3 to a direction avoiding the first device 3 by the switching.

  The control unit 8 is a unit (for example, ECU: Electronic Control Unit) that performs electrical control in the in-vehicle power generation system 1, and is configured by a microcomputer including a CPU, a ROM, a RAM, and the like.

As indicated by a broken line in FIG. 1, the control unit 8 is electrically connected to the afterburn prediction device 5 and the wetness prediction device 6 and electrically connected to the flow path restriction device 7, which will be described later. As described above, when the occurrence of afterburn is predicted by the afterburn prediction device 5 and / or when the occurrence of moisture in the first device 3 is predicted by the moisture prediction device 6, the flow path restriction device 7 is operable.
2. Power Generation Method Hereinafter, a power generation method using the above-described on-vehicle power generation system 1 will be described in detail.

  In this in-vehicle power generation system 1, the piston 11 is repeatedly moved up and down in the cylinder 12 by driving the engine 11. Thus, for example, in the 4-cycle system, an intake process, a compression process, an explosion process, an exhaust process, and the like are sequentially performed. To be implemented.

  More specifically, in the engine 11, first, the throttle valve 27 is opened, air is supplied from the intake pipe 16, and a predetermined amount of fuel is supplied (injected) from the fuel supply pipe 22 by the fuel injection valve 23. And they are mixed. Then, the air-fuel mixture is supplied to the combustion chamber 14 of the cylinder 12 by opening the intake valve 18 (intake process).

  Next, the intake valve 18 is closed and the piston 13 is raised, so that the air-fuel mixture in the combustion chamber 14 is compressed and heated to a high temperature (compression process).

  Next, the air-fuel mixture is ignited by an ignition plug (not shown) and burned explosively, and the piston 13 is pushed down by the explosion (explosion process).

  Thereafter, the exhaust valve 19 is opened, and the gas (exhaust gas) generated by the combustion is exhausted from the cylinder 12 (exhaust process).

  As described above, in the engine 11, the fuel is combusted and power is output, and high-temperature exhaust gas passes through the exhaust pipe 17 in the exhaust process.

  At this time, the heat of the engine 11 is transmitted through the exhaust gas, and the temperature of the exhaust gas (the internal temperature of the exhaust pipe 17) rises in the exhaust process. On the other hand, in other processes (intake process, compression process, explosion process), the amount of exhaust gas in the exhaust pipe 17 is reduced, so the temperature of the exhaust gas (internal temperature of the exhaust pipe 17) decreases.

  As described above, the temperature of the exhaust gas 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 repeated sequentially according to the piston cycle, the exhaust gas periodically changes in temperature with the repetition cycle of each of the above steps, more specifically, The high temperature state and the low temperature state are periodically repeated.

  In such an in-vehicle power generation system 1, the temperature of the internal combustion engine 2 and the exhaust gas 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 the above-described temperature. Less 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., 20 to 500 ° C.

  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.

  In the in-vehicle power generation system 1, as described above, the first device 3 is disposed inside the exhaust pipe 17.

  At this time, the flow path regulating device 7 opens the exhaust pipe 17 and closes the sub exhaust pipe 29.

  Therefore, when exhaust gas discharged from the engine 11 (internal combustion engine 2) is introduced into the exhaust pipe 17, the exhaust gas is supplied to the first device 3 in the exhaust pipe 17, and the first device 3 The exhaust gas is contacted (exposed) through the second device 4 and heated and / or cooled.

  In other words, the first device 3 is heated and / or cooled by the temperature change over time of the engine 11 (internal combustion engine 2) and the exhaust gas that transfers the heat of the engine 11.

  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 in-vehicle power generation system 1, the electric 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. 1, the electric power obtained as described above is boosted by a booster (not shown) connected to the second device 4 as necessary, and AC / DC conversion is performed. After being converted to a DC voltage in a container (not shown), the battery 9 is charged. The electric power stored in the battery 9 can be used as appropriate as power for the automobile 10 and various electric components mounted on the automobile 10.

On the other hand, the exhaust gas used for power generation passes through the first device 3 and is then purified by a known catalyst or the like and discharged to the outside air.
3. Afterburning and flooding In the automobile 10 on which the above-described on-vehicle power generation system 1 is mounted, occurrence of afterburning or flooding of the first device 3 may be predicted depending on the traveling conditions. Hereinafter, the case where each occurrence is predicted will be described in detail.
(1) Afterburning Afterburning, fuel that has not been burned in the combustion chamber 14 (unburned fuel) or fuel that has not been burned (incompletely burned fuel) is discharged from the cylinder 12 to the exhaust pipe 17. This is a phenomenon of combustion (explosion) in the exhaust pipe 17 and is caused by various factors.

  For example, when the throttle valve 27 is increased by depressing the accelerator pedal to increase the air supply amount and the fuel supply amount by the fuel injection valve 23 during the operation of the automobile 10, The amount of increase in air may be insufficient with respect to the amount of increase in the amount of fuel, and fuel may be excessive in the cylinder 12.

  If excessive fuel is supplied into the cylinder 12, the fuel cannot be burned sufficiently, and unburned fuel or incompletely burned fuel may be discharged to the exhaust pipe 17.

  Further, for example, when the accelerator pedal is returned and the throttle valve 27 is closed, the supply of air is stopped, so that the fuel adhering to the vicinity of the intake valve 18 is supplied to the cylinder 12 by negative pressure. In some cases, the amount of fuel in the cylinder 12 becomes excessive. In the same manner as described above, if excessive fuel is supplied, combustion cannot be sufficiently performed in the cylinder 12, and unburned fuel or incompletely burned fuel may be discharged to the exhaust pipe 17.

  As described above, when excess fuel is supplied into the cylinder 12 by opening and closing the throttle valve 27 and its opening, unburned fuel or incompletely burned fuel may be discharged to the exhaust pipe 17. In such a case, the occurrence of afterburn in the exhaust pipe 17 is predicted.

  The occurrence of afterburn is not limited to the above, but is predicted due to various other factors. Specifically, for example, if a spark plug (not shown) provided in the cylinder 12 is worn, an ignition failure may occur during combustion of the fuel, and the fuel may not be sufficiently combusted. Even in such a case, unburned fuel or incompletely burned fuel may be discharged to the exhaust pipe 17 and afterburn may occur.

  For example, although not shown, in the automobile 10, a limiter (not shown) such as a speed limiter may be operated by stopping ignition by a spark plug (not shown) or delaying ignition. . Even in such a case, unburned fuel or incompletely burned fuel may be discharged to the exhaust pipe 17 and afterburn may occur.

  When unburned fuel or incompletely burned fuel is discharged to the exhaust pipe 17 in this way and afterburn occurs in the exhaust pipe 17, the first device 3 may be damaged due to the impact or the like.

  Therefore, in this in-vehicle power generation system 1, in order to suppress the damage of the first device 3, the occurrence of afterburn is predicted, and the flow direction of the exhaust gas is directed toward the first device 3 based on the prediction. To the direction to avoid the first device 3.

  Specifically, in the in-vehicle power generation system 1, first, the occurrence of afterburn is predicted by the afterburn prediction device 5.

  Specifically, the afterburn predicting device 5 detects the operating conditions of the afterburn generation factors (for example, the throttle valve 27, the spark plug (not shown), the limiter (not shown), etc.), and the above-mentioned afterburning is performed. The occurrence of afterburn is predicted by determining whether or not the condition for occurrence of burn is met.

  When the afterburn prediction device 5 predicts the occurrence of afterburning, the control unit 8 activates the flow path restricting device 7 to close the exhaust pipe 17 on the upstream side of the first device 3. The exhaust pipe 29 is opened.

  Thereby, the exhaust gas flowing through the exhaust pipe 17 is introduced into the sub exhaust pipe 29 by the flow path restriction device 7, and the flow direction of the exhaust gas flowing toward the first device 3 is in a direction to avoid the first device 3. Be changed. And exhaust gas is introduced into the sub exhaust pipe 29 from the upstream side of the first device 3 so as to avoid the first device 3, and is introduced again into the exhaust pipe 17 on the downstream side of the first device 3. It is purified by a catalyst and discharged to the outside air.

According to such an in-vehicle power generation system 1, when the occurrence of afterburn is predicted, the exhaust gas flows in a direction to avoid the first device 3. Therefore, it is possible to suppress the occurrence of afterburning in the vicinity of the first device 3, and it is possible to suppress the damage of the first device 3 due to the impact.
(2) Water Coverage In the above-described on-vehicle power generation system 1, the water vapor contained in the exhaust gas discharged from the cylinder 12 may be cooled, and condensed water may be generated on the inner wall of the exhaust pipe 17.

  Specifically, for example, immediately after the engine 11 is started, the inner wall temperature of the exhaust pipe 17 may be below or near the dew point of the exhaust gas. In such a case, the exhaust gas is discharged from the engine 11. The exhaust gas is cooled in the exhaust pipe 17. Then, the water vapor contained in the exhaust gas is cooled, whereby solidified water is generated on the inner wall of the exhaust pipe 17.

  When condensed water is generated in this way, the condensed water may be transported by exhaust gas and adhere to the first device 3, that is, the first device 3 may be wet.

  In such a case, since the first device 3 is rapidly cooled, the first device 3 may be damaged.

  Therefore, in this in-vehicle power generation system 1, in order to suppress the damage of the first device 3, the generation of water in the first device 3 is predicted, and the flow direction of the exhaust gas is determined based on the prediction. Is changed from the direction of flowing toward the first direction to avoid the first device 3.

  Specifically, in this in-vehicle power generation system 1, first, the occurrence of water exposure is predicted by the water exposure prediction device 6.

  Specifically, the temperature sensor 15 detects the inner wall temperature of the exhaust pipe 17 upstream of the first device 3. Then, it is determined whether or not the temperature detected by the temperature sensor 15 is equal to or lower than the dew point of the exhaust gas or the temperature in the vicinity of the dew point.

  If the inner wall temperature of the exhaust pipe 17 is equal to or lower than the dew point of the exhaust gas or a temperature near the dew point, when the exhaust gas is discharged from the cylinder 12 to the exhaust pipe 17, the water vapor in the exhaust gas is cooled, and the exhaust pipe 17 Condensed water is generated on the inner wall of the first device 3, and the condensed water may cause water in the first device 3.

  Therefore, it is predicted whether or not the inner wall temperature of the exhaust pipe 17 is equal to or lower than the dew point of the exhaust gas or a temperature near the dew point.

  And when generation | occurrence | production of the flooding of the 1st device 3 is estimated by the flooding prediction apparatus 6, the flow control apparatus 7 is actuated by the control unit 8, and the exhaust pipe 17 is connected upstream of the 1st device 3. The auxiliary exhaust pipe 29 is opened while being closed.

  Thereby, the exhaust gas flowing through the exhaust pipe 17 is introduced into the sub exhaust pipe 29 by the flow path restriction device 7, and the flow direction of the exhaust gas flowing toward the first device 3 is in a direction to avoid the first device 3. Be changed. And exhaust gas is introduced into the sub exhaust pipe 29 from the upstream side of the first device 3 so as to avoid the first device 3, and is introduced again into the exhaust pipe 17 on the downstream side of the first device 3. It is purified by a catalyst and discharged to the outside air.

According to such an in-vehicle power generation system 1, when condensed water is generated in the exhaust pipe 17 and generation of water in the first device 3 is predicted, the exhaust gas tends to avoid the first device 3. Flowing. Therefore, it can suppress that water is conveyed by exhaust gas and adheres to the 1st device 3, and it can suppress that the 1st device 3 is rapidly cooled and damaged with the water.
4). 2nd Embodiment FIG. 2: is a principal part schematic block diagram of other embodiment (2nd Embodiment) of the vehicle-mounted electric power generation system of this invention.

  In the above description, the exhaust pipe 17 is provided with the auxiliary exhaust pipe 29, the exhaust gas is introduced into the auxiliary exhaust pipe 29 by the flow path restriction device 7, and the flow direction of the exhaust gas flowing toward the first device 3 is determined as the first direction. For example, the flow direction of the exhaust gas flowing toward the first device 3 may be changed to a direction avoiding the first device 3 without providing the auxiliary exhaust pipe 29. it can.

  In this embodiment, as shown in FIG. 2, the exhaust pipe 17 is not provided with a sub exhaust pipe 29, and a substantially rectangular parallelepiped box-shaped space 30 is interposed in the exhaust pipe 17. The first device 3 is arranged in the box space 30 so as to be unevenly distributed on one side in the vehicle height direction.

  In this embodiment, the flow path restriction device 7 includes a substantially flat plate-like restriction member 25, and is swingably fixed upstream of the first device 3 in the box-shaped space 30. Yes.

  Specifically, the flow path regulating device 7 has one end fixed to the inner surface of the box-shaped space 30 via a hinge, and a position for opening the box-shaped space along the inner surface of the box-shaped space 30. Then, the box-shaped space 30 is oscillated to a position where the box-shaped space 30 is semi-closed by standing obliquely.

  In such a flow path regulating device 7, the swing of the regulating member 25 is controlled by the control unit 8, and the box-shaped space 30 can be opened and semi-closed by the swing. As a result, the flow path restriction device 7 regulates the flow direction of the exhaust gas and can change the flow direction of the exhaust gas flowing toward the first device 3 to a direction avoiding the first device 3.

  In such an in-vehicle power generation system 1, as described above, afterburn may occur in the exhaust pipe 17 or the first device 3 may be wetted. In such a case, the same as above In some cases, the first device 3 may be damaged.

  Therefore, also in such an in-vehicle power generation system 1, in order to suppress the damage of the first device 3, the occurrence of afterburning and / or the occurrence of water on the first device 3 is predicted, and based on the prediction, The flow direction of the exhaust gas is changed from the direction flowing toward the first device 3 to the direction avoiding the first device 3.

  Specifically, first, the occurrence of afterburn is predicted by the afterburn prediction device 5 in the same manner as described above, and the occurrence of water in the first device 3 is predicted by the water prediction device 6.

  When the occurrence of afterburn is predicted by the afterburn prediction device 5 and / or when the occurrence of moisture in the first device 3 is predicted by the moisture prediction device 6, the flow is controlled by the control unit 8. The road regulating device 7 is operated and the regulating member 25 is swung. Thereby, the box-shaped space 30 is semi-closed on the upstream side of the first device 3 (see the broken line in FIG. 2).

  The degree of occlusion in the semi-occlusion is not particularly limited, but preferably, the regulating member 25 is swung so that the distal end portion of the regulating member 25 of the flow path regulating device 7 has the same height as the thickness of the first device 3. The box-shaped space 30 is semi-closed.

  As a result, the flow direction of the exhaust gas is regulated by the flow path regulating device 7, and the flow direction of the exhaust gas flowing toward the first device 3 is changed to a direction avoiding the first device 3 (arrow in FIG. 2). reference). Then, the exhaust gas flows from the upstream side to the downstream side of the first device 3 so as to avoid the first device 3, is purified by a known catalyst or the like, and is discharged to the outside air.

  According to such an in-vehicle power generation system 1, when the occurrence of afterburn is predicted, the exhaust gas flows in a direction to avoid the first device 3. Therefore, it is possible to suppress the occurrence of afterburning in the vicinity of the first device 3, and it is possible to suppress the damage of the first device 3 due to the impact.

  Also in such an in-vehicle power generation system 1, when condensed water is generated in the exhaust pipe 17 and generation of water in the first device 3 is predicted, the direction in which the exhaust gas avoids the first device 3. Flowing into. Therefore, it can suppress that water is conveyed by exhaust gas and adheres to the 1st device 3, and it can suppress that the 1st device 3 is rapidly cooled and damaged with the water.

  In the above description, the afterburn prediction device 5, the wetness prediction device 6, the control unit 8, and the engine control unit 28 are provided as separate bodies. For example, the afterburn prediction device 5, the wetness prediction Two or more of the apparatus 6, the control unit 8, and the engine control unit 28 may be provided integrally.

DESCRIPTION OF SYMBOLS 1 In-vehicle power generation system 2 Internal combustion engine 3 1st device 4 2nd device 5 Afterburn prediction apparatus 6 Water-prediction apparatus 7 Flow path control apparatus 8 Control unit 11 Engine 17 Exhaust pipe

Claims (1)

An internal combustion engine comprising an engine and an exhaust pipe for discharging exhaust gas from the engine;
A first device disposed in the exhaust pipe and electrically polarized by being supplied with an exhaust gas whose temperature rises and falls over time;
A second device for extracting power from the first device;
Afterburn predicting means for predicting the occurrence of afterburn in the exhaust pipe, and / or wetness predicting means for predicting the occurrence of moisture in the first device;
A flow direction changing means for changing a flow direction of the exhaust gas flowing toward the first device in the exhaust pipe to a direction avoiding the first device;
The flow direction changing means is operated when occurrence of afterburn is predicted by the afterburn prediction means and / or when occurrence of water in the first device is predicted by the water prediction means. An on-vehicle power generation system comprising a control means.

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