Fuel reform apparatus includes: internal combustion engine including injector and configured so that compression-ignition combustion is carried out in combustion chamber; reform unit interposed in fuel supply path from fuel tank to injector and including reformer reforming fuel stored in fuel tank by oxidation reaction; and controller including CPU and memory. Controller performs: estimating progress level of oxidation reaction in reformer; and controlling operation of reform unit based on progress level of oxidation reaction estimated.

Fuel reform apparatus includes: internal combustion engine including injector and configured so that compression-ignition combustion is carried out in combustion chamber; reform unit interposed in fuel supply path from fuel tank to injector and including reformer reforming fuel stored in fuel tank by oxidation reaction; and controller including CPU and memory. Controller performs: estimating progress level of oxidation reaction in reformer; and controlling operation of reform unit based on progress level of oxidation reaction estimated.

Fuel reform apparatus includes: internal combustion engine including injector and configured so that compression-ignition combustion is carried out in combustion chamber; reform unit interposed in fuel supply path from fuel tank to injector and including reformer reforming fuel stored in fuel tank by oxidation reaction; ignition timing detector detecting ignition timing of fuel in combustion chamber; and controller including CPU and memory. Controller performs: determining whether fuel has been supplied into fuel tank; determining whether reforming is needed based on ignition timing when it is determined that fuel has been supplied; controlling operation of reform unit so as to reform fuel stored in fuel tank to supply to injector when it is determined that reforming is needed; and controlling operation of reform unit so as to supply fuel stored in fuel tank to injector without reforming when it is determined that reforming is not needed.

An engine system includes: an ammonia engine; a reforming device that has a reforming catalyst for cracking ammonia gas into hydrogen and configured to reform ammonia gas to generate reformed gas containing hydrogen; and a control unit. The control unit includes: a purge controller configured to control a reforming injector so as to be closed and control a reforming throttle valve so as to be opened, after an ignition switch gives an instruction of a stop of the ammonia engine; and an engine stop controller configured to control main injectors so as to be closed, after the ignition switch gives the instruction of the stop of the ammonia engine.

An engine system includes: an ammonia engine; a reforming device that has a reforming catalyst for cracking ammonia gas into hydrogen and configured to reform ammonia gas to generate reformed gas containing hydrogen; and a control unit. The control unit includes: a purge controller configured to control a reforming injector so as to be closed and control a reforming throttle valve so as to be opened, after an ignition switch gives an instruction of a stop of the ammonia engine; and an engine stop controller configured to control main injectors so as to be closed, after the ignition switch gives the instruction of the stop of the ammonia engine.

An engine system includes an engine having a combustion chamber, an intake gas passage through which air to be supplied to the combustion chamber flows, an exhaust gas passage through which exhaust gas generated from the combustion chamber flows, a reformer configured to reform the fuel to generate a reformed gas containing hydrogen, a gas supply passage through which air to be supplied to the reformer flows, a bypass passage connected to the gas supply passage and the exhaust gas passage so as to bypass the reformer and through which the fuel having passed through the reformer is circulated to an upstream of the reformer, and a switching valve switched between a normal position that does not allow the fuel having passed through the reformer to flow to the bypass passage and a circulating position that allows the fuel having passed through the reformer to flow to the bypass passage.

An engine includes a reformer, a reforming-air adjuster, a reforming-fuel supply unit, a reformed-gas adjuster, and a control unit. The reformer is configured to reform fuel into a reformed gas. When a start signal is input, the control unit controls the reforming-air adjuster and the reforming-fuel supply unit to a reformable state in which the fuel is reformable in the reformer, and the control unit controls the reformed-gas adjuster so that the reformed gas flows through the reformed-gas adjuster with a degree of opening smaller than a normal degree of opening that is a degree of opening of the reformed-gas adjuster when composition of the reformed gas is in a stable state before the composition of the reformed gas becomes in the stable state, for a given period of time including at least a period immediately after the engine starts.

Some embodiments described herein relate to a method of operating a compression ignition engine. The method of operating the compression ignition engine includes opening an intake valve to draw a volume of air into a combustion chamber, closing an intake valve, and moving a piston from a bottom-dead-center (BDC) position to a top-dead-center (TDC) position in the combustion chamber at a compression ratio of at least about 15:1. The method further includes injecting a volume of fuel into the combustion chamber at an engine crank angle between about 330 degrees and about 365 degrees during a first time period. The fuel has a cetane number less than about 40. The method further includes combusting substantially all of the volume of fuel. In some embodiments, a delay between injecting the volume of fuel into the combustion chamber and initiation of combustion is less than about 2 ms.

Provided is a hydrogen reformer using exhaust gas, comprising: a catalytic reaction unit which generates a reforming gas containing hydrogen when exhaust gas generated in an engine and fuel are supplied thereto; and a heat exchange chamber which is mounted on an outer surface of the catalytic reaction unit and exchanges heat between the exhaust gas and the catalytic reaction unit to supply heat that is required for an endothermic reaction of the catalytic reaction unit, wherein heat of the exhaust gas is used for the endothermic reaction of a catalyst, such that a separate heat source for the endothermic reaction is unnecessary.

An internal combustion engine assembly is provided with a fuel tank for fuel including ethanol, and a reformer for steam reforming of ethanol that is with an outlet connected to a buffer tank. A first reformer supply duct extends from the fuel tank to the reformer via a fuel evaporator that is in heat exchanging contact with the exhaust gases, for supplying ethanol vapor to the reformer. A second reformer supply duct extends from a water reservoir to the reformer via a water evaporator that is in heat exchanging contact with the exhaust gases. The reformer is in heat exchanging contact with the catalytic converter and is adapted for reforming ethanol and water into syngas including carbon monoxide and hydrogen, and for supplying the syngas via the outlet to the buffer tank. The reformer and the catalytic converter may form an integrated unit.