Abstract: Fuel reforming catalysts 28 generate a hydrogen-containing reformed gas when they come into contact with exhaust gas that contains a reforming fuel. Upstream and downstream air-fuel ratio sensors 58, 60 are respectively installed upstream and downstream of the fuel reforming catalysts 28. The upstream air-fuel ratio sensor 58 outputs a upstream sensor signal in accordance with oxygen concentration. The downstream air-fuel ratio sensor 60 outputs a downstream sensor signal in accordance with oxygen concentration and hydrogen concentration by using zirconia's oxygen detection capability and a change of a diffusion layer's hydrogen-concentration-dependent oxygen detection capability. An ECU 50 detects the hydrogen concentration without being affected by the oxygen concentration through the use of the upstream sensor signal in which only the oxygen concentration is reflected and the downstream sensor signal in which the oxygen concentration and hydrogen concentration are reflected.

Abstract: In an exhaust purification system that purifies exhaust from a plurality of cylinder groups of an internal combustion engine, an exhaust passageway (1,51) from each cylinder group is divided into a plurality of passageways (2a, 2b, 52a, 52b/3,53). With regard to one or more of the divided exhaust passageways (3,53), the amount of exhaust passing therethrough is reduced so as to reduce the heat release to the outside from the exhaust as a whole. In this manner, the temperature of exhaust introduced into an exhaust purification device (4,54) is kept at high temperature.

Abstract: Fuel reforming catalysts 28 generate a hydrogen-containing reformed gas when they come into contact with exhaust gas that contains a reforming fuel. Upstream and downstream air-fuel ratio sensors 58, 60 are respectively installed upstream and downstream of the fuel reforming catalysts 28. The upstream air-fuel ratio sensor 58 outputs a upstream sensor signal in accordance with oxygen concentration. The downstream air-fuel ratio sensor 60 outputs a downstream sensor signal in accordance with oxygen concentration and hydrogen concentration by using zirconia's oxygen detection capability and a change of a diffusion layer's hydrogen-concentration-dependent oxygen detection capability. An ECU 50 detects the hydrogen concentration without being affected by the oxygen concentration through the use of the upstream sensor signal in which only the oxygen concentration is reflected and the downstream sensor signal in which the oxygen concentration and hydrogen concentration are reflected.

Abstract: An internal combustion engine operable with a mixed fuel composed of alcohol and gasoline and excellent in fuel efficiency and durability. A separator separates the mixed fuel, which is composed of gasoline and ethanol, into high-concentration ethanol and high-concentration gasoline. A reforming fuel supply device supplies the high-concentration ethanol, as a reforming fuel, into an exhaust gas removed through a branch pipe. A fuel reforming catalyst supported in a reforming chamber within a heat exchanger works to cause a reforming reaction between the high-concentration ethanol and exhaust gas and generate a reformed gas that contains H2 and CO. The reformed gas is supplied into an intake pipe of the internal combustion engine via a reformed gas conduit pipe. The separated high-concentration ethanol and high-concentration gasoline are remixed by a mixer and supplied from a fuel injection device to the internal combustion engine.

Abstract: In an exhaust purification system that purifies exhaust from a plurality of cylinder groups of an internal combustion engine, an exhaust passageway (1,51) from each cylinder group is divided into a plurality of passageways (2a, 2b, 52a, 52b/3,53). With regard to one or more of the divided exhaust passageways (3,53), the amount of exhaust passing therethrough is reduced so as to reduce the heat release to the outside from the exhaust as a whole. In this manner, the temperature of exhaust introduced into an exhaust purification device (4,54) is kept at high temperature.

Abstract: An internal combustion engine capable of reforming and recycling a portion of fuel included in exhaust gas from a combustion chamber includes an exhaust passage where exhaust gas from the combustion chamber flows; a reformer that has a reforming reaction chamber including a fuel reforming catalyst; a branch passage that branches from the exhaust passage at a branch portion provided upstream from the reformer, and directs exhaust gas to the reforming reaction chamber; and a secondary air supplier and an exhaust purification catalyst serving as fuel removal means, which are provided downstream from the branch portion.

Abstract: An internal combustion engine capable of reforming and recycling a portion of fuel included in exhaust gas from a combustion chamber includes an exhaust passage where exhaust gas from the combustion chamber flows; a reformer that has a reforming reaction chamber including a fuel reforming catalyst; a branch passage that branches from the exhaust passage at a branch portion provided upstream from the reformer, and directs exhaust gas to the reforming reaction chamber; and a secondary air supplier and an exhaust purification catalyst serving as fuel removal means, which are provided downstream from the branch portion.