JP2013189884A - Reformed gas supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate reformed gas containing hydrogen from a raw material gas when the temperature of an internal combustion engine is low.SOLUTION: A reformed gas generator 12 is connected with a canister 15 for treating evaporation fuel generated in a fuel tank 14, and a steam supply device 16. The reformed gas generator 12 is supplied with a purge gas (raw material gas) from the canister 15 and steam from the steam supply device 16. By applying predetermined voltage to a catalyst 21 even if temperatures of the catalyst 21 and the supplied raw material gas are low, the reformed gas generator 12 can generate a reformed gas containing hydrogen by using the raw material gas. Further, the reformed gas is introduced via a reformed gas introduction path 13 to an intake passage. Thereby, even if the internal combustion engine 1 is in a low temperature state, hydrogen is generated by reformation of the raw material gas and can be supplied to the internal combustion engine 1, and combustion in the internal combustion engine 1 can be promoted.

Description

  The present invention relates to a reformed gas supply apparatus capable of generating a reformed gas containing hydrogen at a low temperature by applying a voltage to a catalyst and supplying the generated hydrogen to an intake system of an internal combustion engine.

  In recent years, a technique for adding hydrogen to an air-fuel mixture has been developed for the purpose of promoting combustion in an internal combustion engine. For example, Patent Document 1 discloses that a hydrogenated fuel obtained by adding hydrogen to gasoline is reformed by a catalyst using exhaust heat of an internal combustion engine and separated into hydrogen and a dehydrogenated product (gasoline). A technique for generating hydrogen to be supplied to an air-fuel mixture is disclosed.

JP 2006-226167 A

  However, as in Patent Document 1, when the fuel is reformed by utilizing exhaust heat, the reforming reaction temperature at the catalyst is high. There is a problem that cannot be generated. Therefore, in order to promote combustion using hydrogen at a low temperature of the internal combustion engine, only hydrogen is separated and stored in a tank or the like, which causes a problem that the apparatus becomes complicated and large. is there.

  Accordingly, the reformed gas supply apparatus of the present invention is a reformed gas generator capable of generating a reformed gas containing hydrogen at a low temperature using a raw material gas by applying a voltage to a catalyst having a dielectric supported on a noble metal. And a source gas supply unit for supplying the source gas to the reformed gas generator. The reformed gas is introduced into the intake system of the internal combustion engine.

  According to the present invention, even when the internal combustion engine is in a low temperature state, hydrogen can be generated by reforming the raw material gas in the reformed gas generator and supplied to the internal combustion engine, thereby promoting combustion of the internal combustion engine. be able to.

  In addition, the reformed gas generator can generate reformed gas containing hydrogen from the raw material gas regardless of the temperature state of the internal combustion engine, so that only hydrogen is separated and stored in a tank or the like for promoting combustion of the internal combustion engine. In addition, hydrogen can be introduced into the intake system of the internal combustion engine as necessary without causing the apparatus to become complicated or large.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed typically the whole structure of the reformed gas supply apparatus in 1st Example of this invention. Explanatory drawing which showed the outline of the reformed gas generator typically. Explanatory drawing which showed typically the whole structure of the reformed gas supply apparatus in 2nd Example of this invention. Explanatory drawing which showed typically the whole structure of the reformed gas supply apparatus in 3rd Example of this invention. Explanatory drawing which showed typically the whole structure of the reformed gas supply apparatus in 4th Example of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing the overall configuration of the reformed gas supply apparatus in the first embodiment of the present invention.

  The internal combustion engine 1 is mounted on a vehicle such as an automobile. An intake passage 4 is connected to the combustion chamber 2 of the internal combustion engine 1 via an intake valve 3 and an exhaust passage 6 is connected via an exhaust valve 5. A spark plug 7 for spark-igniting the air-fuel mixture in the combustion chamber 2 is provided at the central top of the combustion chamber 2.

  An air flow meter 8 that detects the intake air amount, a throttle valve 9 that controls the intake air amount, and a fuel injection valve 10 that injects and supplies fuel (hydrocarbon compounds such as gasoline) are disposed in the intake passage 4.

  Here, various controls of the internal combustion engine 1 such as the fuel injection amount of the fuel injection valve 10, the valve opening degree of the throttle valve 9, and the ignition timing of the spark plug 7 are performed by an ECU (engine control unit) 11. In addition to the detected value of the air flow meter 8, signals from various sensors are input to the ECU 11.

  Further, a reformed gas introduction path 13 for introducing reformed gas containing hydrogen generated by the reformed gas generator 12 is connected to the intake passage 4 at a position downstream of the throttle valve 9.

  The reformed gas generator 12 is connected to a canister 15 (raw material gas supply unit) for processing the evaporated fuel generated in the fuel tank 14 and a water vapor supply unit 16 for generating water vapor to purge the canister 15. The purge gas composed of air and evaporated fuel and the water vapor supplied from the water vapor supply device 16 are supplied.

  One end of a purge air introduction path 17 is connected to the canister 15 for introducing air when purging the evaporated fuel adsorbed on the canister 15 (light component of the fuel). The other end of the purge air introduction path 17 is connected to the intake passage 4 at a position between the throttle valve 9 and the air flow meter 8. Then, the purge gas as the raw material gas is supplied to the reformed gas generator 12 through the purge gas passage 18. In the present embodiment, the other end of the purge air introduction passage 17 is connected to the intake passage 4. However, the other end of the purge air introduction passage 17 is opened to the atmosphere, and is required for purging the canister 4. Air may be introduced from other than the intake passage 4.

  The water vapor supply device 16 supplies water vapor to the reformed gas generator 12, and for example, heat evaporation that heats and vaporizes water as a raw material with an electric heater or the like, or water as a raw material with ultrasonic waves Water vapor is generated by either ultrasonic evaporation for atomization and evaporation, or evaporation by spraying water as a raw material. The steam supplier 16 supplies steam to the reformed gas generator 12 when the raw material gas is supplied to the reformed gas generator 12.

  FIG. 2 is an explanatory view schematically showing the outline of the reformed gas generator 12. The reformed gas generator 12 includes a catalyst 21 and a pair of electrodes 22, 22 that can apply a predetermined voltage to the catalyst 21 and allow a current to flow through the catalyst 21.

  The catalyst 21 is obtained by supporting a noble metal on a dielectric. More specifically, for example, the above-mentioned dielectric is coated on a honeycomb monolith support made of cordierite, and the noble metal is further supported thereon. Formed with.

  As the dielectric in the catalyst 21, for example, cerium oxide (CeO2) or zirconium oxide (CeO2-ZrO2) is preferably used. In addition, as the noble metal supported on the dielectric, for example, platinum (Pt), palladium (Pd), rhodium (Rh) or the like is preferably used, but nickel (Ni), cobalt (Co), or the like is used. Even when used, a reformed gas containing hydrogen can be generated from the raw material gas at a low temperature.

  The pair of electrodes 22 and 22 are arranged so as to be in direct contact with the catalyst, respectively, but may be arranged so as not to be in direct contact with the catalyst 21. Further, the application of voltage to the electrodes 22 and 22 is controlled by the ECU 11.

  The reformed gas generator 12 applies a predetermined voltage to the catalyst 21, so that even if the catalyst 21 and the supplied raw material gas are at a low temperature, the raw material gas and water vapor are used to contain hydrogen. A reformed gas can be generated. The reformed gas is a mixed gas containing carbon monoxide, carbon dioxide, methane and the like in addition to hydrogen.

  The timing of generating the reformed gas by the reformed gas generator 12 is, for example, when the internal combustion engine 1 is in a low temperature state such as when the engine is started. At such timing, purging of the canister 15 is executed by a command from the ECU 11, and water vapor is generated by the water vapor supplier 16 according to a command from the ECU 11. The canister 15 is purged by, for example, opening a purge control valve (not shown) provided in the purge gas passage 18. Further, even when the internal combustion engine 1 is not started, if the amount of evaporated fuel adsorbed by the canister 15 increases, the canister 15 is purged when the internal combustion engine 1 is operated at a high load. Water vapor may not be supplied to the reformed gas generator 12 so that the reformed gas is not generated.

  In such a reformed gas supply apparatus of the first embodiment, even when the internal combustion engine 1 is in a low temperature state, the reformed gas generator 12 generates the reformed gas containing hydrogen by reforming the raw material gas. Thus, the combustion of the internal combustion engine 1 can be promoted by the hydrogen in the reformed gas.

  Since the reformed gas generator 12 can generate the reformed gas containing hydrogen from the raw material gas regardless of the temperature state of the internal combustion engine 1, only hydrogen is supplied to the tank or the like for promoting combustion of the internal combustion engine 1. Hydrogen can be introduced into the intake system of the internal combustion engine 1 as needed without the need for separate storage and without complicating or increasing the size of the apparatus.

  Since the purged gas is supplied to the reformed gas generator 12 by using the evaporated fuel as the air introduced along with the purge, the evaporated fuel can be smoothly supplied to the reformed gas generator 12.

  Further, since the evaporative fuel is supplied to the reformed gas generator 12 using the air in the intake passage 4 having a low temperature introduced with the purge, the raw material gas itself becomes a low temperature, and the reformed gas It can suppress that hydrogen in it reacts with oxygen. Therefore, even if evaporative fuel is supplied to the reformed gas generator 12 using air, the hydrogen obtained by reforming the raw material gas can be efficiently supplied to the internal combustion engine 1.

  Note that the reformed gas generator 12 generates the reformed gas when the evaporated fuel adsorbed on the canister 15 contains alcohol even if the source gas is composed of only the purge gas. Can do. That is, in the first embodiment, if the fuel in the fuel tank 14 is limited to a fuel containing alcohol such as ethanol, the water vapor supplier 16 can be omitted.

  Hereinafter, other embodiments of the present invention will be described, but the same components as those in the first embodiment described above are denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 3 is an explanatory view schematically showing the overall configuration of the reformed gas supply apparatus in the second embodiment of the present invention. The reformed gas supply device of the second embodiment has substantially the same configuration as the reformed gas supply device of the first embodiment described above, but this second embodiment has a natural gas such as CNG or LNG, for example. A pressure vessel 31 such as a stored cylinder is provided, and natural gas in the pressure vessel 31 is supplied to the reformed gas generator 12 as a raw material gas. The steam supplier 16 supplies steam to the reformed gas generator 12 when the raw material gas is supplied to the reformed gas generator 12.

  Also in the second embodiment, the reformed gas generator 12 applies a predetermined voltage to the catalyst 21 so that the source gas can be supplied even if the catalyst 21 or the supplied source gas is at a low temperature. It is possible to generate a reformed gas containing hydrogen.

  For this reason, also in the second embodiment, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. Further, in the second embodiment, the raw material gas can be supplied to the reformed gas generator 12 even in a situation where the evaporated fuel is not adsorbed by the canister.

  FIG. 4 is an explanatory view schematically showing the overall configuration of the reformed gas supply apparatus in the third embodiment of the present invention. The reformed gas supply apparatus of the third embodiment has substantially the same configuration as the above-described reformed gas supply apparatus of the first embodiment, but this third embodiment evaporates the liquid fuel in the fuel tank 14. The vaporized fuel vaporized by the liquid material evaporator 36 is supplied to the reformed gas generator 12 as a material gas.

  The liquid raw material evaporator 36 is, for example, heated evaporation in which liquid fuel as a raw material is heated and vaporized by an electric heater or the like, or ultrasonic evaporation in which liquid fuel as a raw material is atomized with an ultrasonic wave or evaporated, or becomes a raw material. Evaporated fuel is generated by either evaporation by spraying of liquid fuel. The steam supplier 16 supplies steam to the reformed gas generator 12 when the raw material gas is supplied to the reformed gas generator 12.

  Also in the third embodiment, the reformed gas generator 12 applies a predetermined voltage to the catalyst 21 so that the source gas can be supplied even if the catalyst 21 or the supplied source gas is at a low temperature. It is possible to generate a reformed gas containing hydrogen.

  Therefore, also in the third embodiment, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. Further, in the third embodiment, the raw material gas can be supplied to the reformed gas generator 12 even in a situation where the evaporated fuel is not adsorbed by the canister.

  FIG. 5 is an explanatory view schematically showing the overall configuration of the reformed gas supply apparatus in the fourth embodiment of the present invention. The reformed gas supply device of the fourth embodiment has substantially the same configuration as the reformed gas supply device of the first embodiment described above, but in this fourth embodiment, the liquid fuel in the fuel tank 14 is ethanol. Or it has become a fuel containing alcohol, such as methanol, and has the liquid raw material evaporator 41 which evaporates the liquid fuel containing this alcohol.

  The liquid raw material evaporator 41 is, for example, heating evaporation in which liquid fuel as a raw material is heated and vaporized by an electric heater or the like, or ultrasonic evaporation in which liquid fuel as a raw material is atomized and evaporated, or a raw material. Evaporated fuel is generated by vaporization or evaporation by spraying liquid fuel.

  In the fourth embodiment, the reformed gas generator 12 is connected to one end of an evaporative fuel introduction path 42 that introduces the evaporative fuel generated by the liquid raw material evaporator 41. The other end of the evaporated fuel introduction path 42 is connected to the intake passage 4 at a position between the throttle valve 9 and the air flow meter 8. Then, the evaporated fuel generated by the liquid source evaporator 41 is supplied as a source gas to the reformed gas generator 12 via the evaporated fuel introduction path 42.

  In FIG. 5, 43 is an upstream side open / close valve that opens and closes the other end of the evaporated fuel introduction path 42, and 44 is a downstream side open / close valve that opens and closes a connection part between the reformed gas introduction path 13 and the intake passage 4. Both are controlled to open and close by the ECU 11.

  In the fourth embodiment, when the reformed gas is supplied to the internal combustion engine 1, the upstream side open / close valve 43 and the downstream side open / close valve 44 are opened, and the throttle valve 9 is throttled by using the negative pressure downstream. The fuel vapor generated by the liquid material evaporator 41 together with the air upstream of the valve 9 is introduced into the reformed gas generator 12. Further, when the reformed gas is not supplied to the internal combustion engine 1, both the upstream side open / close valve 43 and the downstream side open / close valve 44 are closed.

  In such a 4th Example, the fuel vapor produced | generated with the liquid raw material evaporator 41 contains alcohol. Therefore, the reformed gas generator 12 applies a predetermined voltage to the catalyst 21 so that the catalyst 21 and the supplied raw material gas are at a low temperature and does not supply steam to the reformed gas generator 12. However, it is possible to generate a reformed gas containing hydrogen using this raw material gas.

  That is, also in the fourth embodiment, it is possible to obtain substantially the same function and effect as those of the first embodiment described above. Further, in the fourth embodiment, it is possible to supply the raw material gas to the reformed gas generator 12 even in a state where the evaporated fuel is not adsorbed by the canister.

  In the fourth embodiment, when there is no need to supply the reformed gas to the internal combustion engine 1, both the upstream side open / close valve 43 and the downstream side open / close valve 44 are closed, so that the reformed gas introduction passage 13 is closed. Since the reformed gas can be temporarily confined in the interior, if the reformed gas in the reformed gas introduction path 13 is used at the time of starting the internal combustion engine 1 after warming up, the effect of improving the combustion of hydrogen As a result, the fuel supply amount at the start can be further reduced, and the exhaust performance at the start can be improved.

  In addition, in order to supply the reformed gas generator 12 with the evaporated fuel generated by the liquid raw material evaporator 41 using the air introduced by opening both the upstream side open / close valve 43 and the downstream side open / close valve 44. The evaporated fuel can be smoothly supplied to the reformed gas generator 12.

  The reformed gas generator 12 is supplied with the evaporated fuel generated by the liquid source evaporator 41 using the air in the intake passage 4 having a low temperature. It can suppress that hydrogen in a quality gas reacts with oxygen. Therefore, even if evaporative fuel is supplied to the reformed gas generator 12 using air, the hydrogen obtained by reforming the raw material gas can be efficiently supplied to the internal combustion engine 1.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Combustion chamber 3 ... Intake valve 4 ... Intake passage 5 ... Exhaust valve 6 ... Exhaust passage 7 ... Spark plug 8 ... Air flow meter 9 ... Throttle valve 10 ... Fuel injection valve 11 ... ECU
DESCRIPTION OF SYMBOLS 12 ... Reformed gas generator 13 ... Reformed gas introduction path 14 ... Fuel tank 15 ... Canister 16 ... Steam supply 17 ... Purge air introduction path 18 ... Purge gas path 21 ... Catalyst 22 ... Electrode

Claims (6)

A reformed gas generator capable of generating a reformed gas containing hydrogen at a low temperature using a source gas by applying a voltage to a catalyst having a noble metal supported on a dielectric, and the source gas in the reformed gas generator A raw material gas supply unit for supplying
A reformed gas supply apparatus for introducing the reformed gas into an intake system of an internal combustion engine.   The source gas supply unit is a canister that adsorbs evaporated fuel evaporated in a fuel tank of the internal combustion engine, and purge gas generated when air is introduced into the canister and the adsorbed evaporated fuel is desorbed is used as the source material. The reformed gas supply device according to claim 1, wherein the reformed gas generator is supplied as a gas to the reformed gas generator.   The reformed gas supply apparatus according to claim 1, wherein the source gas supply unit is a pressure vessel in which the source gas is stored.   2. The reformed gas supply apparatus according to claim 1, wherein the source gas supply unit is a liquid source evaporator that evaporates liquid fuel of the internal combustion engine to generate the source gas.   The liquid raw material evaporator is formed by heating the fuel to vaporize the fuel, ultrasonic evaporation to atomize the fuel by ultrasonic vaporization, or evaporation by spraying the fuel. The reformed gas supply device according to claim 4, wherein   6. The reformed gas supply apparatus according to claim 1, wherein the source gas is supplied from the source gas supply unit to the reformed gas generator using air.

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