Abstract: A subtracting unit calculates a voltage deviation of an output voltage of a DC-to-DC converter from a target voltage. A feedback control variable calculator calculates a feedback control variable in each control cycle. In a control cycle in which a crossing of the output voltage and the target voltage is detected by a feedforward control determination unit, a feedforward control variable calculator calculates a feedforward control variable so that a change in the output voltage is prevented. A switching control signal generator generates a control signal for the DC-to-DC converter for controlling the output voltage, according to a summation of the feedforward control variable and the feedback control variable.

Abstract: A subtracting unit calculates a voltage deviation of an output voltage of a DC-to-DC converter from a target voltage. A feedback control variable calculator calculates a feedback control variable in each control cycle. In a control cycle in which a crossing of the output voltage and the target voltage is detected by a feedforward control determination unit, a feedforward control variable calculator calculates a feedforward control variable so that a change in the output voltage is prevented. A switching control signal generator generates a control signal for the DC-to-DC converter for controlling the output voltage, according to a summation of the feedforward control variable and the feedback control variable.

Abstract: The present invention provides a fuel gasification furnace including a gasification chamber (1) for fluidizing a high-temperature fluidizing medium therein to form a gasification chamber fluidized bed having an interface, and for gasifying a fuel in the gasification chamber fluidized bed, a char combustion chamber (2) for fluidizing a high-temperature fluidizing medium therein to form a char combustion chamber fluidized bed having an interface, and for combusting char generated by gasification in the gasification chamber (1) in the char combustion chamber fluidized bed to heat the fluidizing medium, and a first energy recovery device (109) for using gases generated by the gasification chamber (1) as a fuel. The gasification chamber (1) and the char combustion chamber (2) are integrated with each other.

Abstract: The present invention provides a fuel gasification furnace including a gasification chamber (1) for fluidizing a high-temperature fluidizing medium therein to form a gasification chamber fluidized bed having an interface, and for gasifying a fuel in the gasification chamber fluidized bed, a char combustion chamber (2) for fluidizing a high-temperature fluidizing medium therein to form a char combustion chamber fluidized bed having an interface, and for combusting char generated by gasification in the gasification chamber (1) in the char combustion chamber fluidized bed to heat the fluidizing medium, and a first energy recovery device (109) for using gases generated by the gasification chamber (1) as a fuel. The gasification chamber (1) and the char combustion chamber (2) are integrated with each other.

Abstract: The present invention provides a fuel gasification furnace including a gasification chamber (1) for fluidizing a high-temperature fluidizing medium therein to form a gasification chamber fluidized bed having an interface, and for gasifying a fuel in the gasification chamber fluidized bed, a char combustion chamber (2) for fluidizing a high-temperature fluidizing medium therein to form a char combustion chamber fluidized bed having an interface, and for combusting char generated by gasification in the gasification chamber (1) in the char combustion chamber fluidized bed to heat the fluidizing medium, and a first energy recovery device (109) for using gases generated by the gasification chamber (1) as a fuel. The gasification chamber (1) and the char combustion chamber (2) are integrated with each other.

Abstract: A gasification furnace and a combustion furnace are integrated with each other to form a single fluidized-bed gasification and combustion furnace in which unburned char generated in the gasification furnace is combusted in the combustion furnace, and the thus generated heat of combustion is utilized as a heat source for gasification. The fluidized-bed gasification and combustion furnace (1) comprises a gasification furnace (3) and a combustion furnace (4) which are divided by a first partition wall (2). In the gasification furnace (3), a revolving flow of the fluidized medium is formed by diffusion devices (32, 33) provided on furnace bottoms, and an upward flow of the fluidized medium partly flows in the combustion furnace (4). The combustion furnace (4) is divided into a main partition wall (5).

Abstract: A gasification furnace and a combustion furnace are integrated with each other to form a single fluidized-bed gasification and combustion furnace in which unburned char generated in the gasification furnace is combusted in the combustion furnace, and the thus generated heat of combustion is utilized as a heat source for gasification. The fluidized-bed gasification and combustion furnace (1) comprises a gasification furnace (3) and a combustion furnace (4) which are divided by a first partition wall (2). In the gasification furnace (3), a revolving flow of the fluidized medium is formed by diffusion devices (32, 33) provided on furnace bottoms, and an upward flow of the fluidized medium partly flows in the combustion furnace (4). The combustion furnace (4) is divided into a main partition wall (5).

Abstract: The present invention provides a fuel gasification furnace including a gasification chamber (1) for fluidizing a high-temperature fluidizing medium therein to form a gasification chamber fluidized bed having an interface, and for gasifying a fuel in the gasification chamber fluidized bed, a char combustion chamber (2) for fluidizing a high-temperature fluidizing medium therein to form a char combustion chamber fluidized bed having an interface, and for combusting char generated by gasification in the gasification chamber (1) in the char combustion chamber fluidized bed to heat the fluidizing medium, and a first energy recovery device (109) for using gases generated by the gasification chamber (1) as a fuel. The gasification chamber (1) and the char combustion chamber (2) are integrated with each other.

Abstract: The present invention provides a fuel gasification furnace including a gasification chamber (1) for fluidizing a high-temperature fluidizing medium therein to form a gasification chamber fluidized bed having an interface, and for gasifying a fuel in the gasification chamber fluidized bed, a char combustion chamber (2) for fluidizing a high-temperature fluidizing medium therein to form a char combustion chamber fluidized bed having an interface, and for combusting char generated by gasification in the gasification chamber (1) in the char combustion chamber fluidized bed to heat the fluidizing medium, and a first energy recovery device (109) for using gases generated by the gasification chamber (1) as a fuel. The gasification chamber (1) and the char combustion chamber (2) are integrated with each other.

Abstract: An apparatus for treating wastes includes a fluidized bed reactor for partially combusting the wastes at a relatively low temperature, and a separate relatively high temperature reactor for separate gasification of gaseous material and char from the first gasification. This synthesis gas thus formed is cooled, subjected to a conversion operation in a converter to produce hydrogen.

Abstract: Combustibles such as wastes are gasified in a fluidized bed. A fluidized-bed furnace has a heat recovery region in addition to a combustion region. The temperature of a fluidized bed or the temperature of a freeboard is controlled so as to be kept at a predetermined value by adjusting the heat recovery rate in the heat recovery region.

Abstract: A method and apparatus for treating wastes by two-stage gasification recovers metals or ash content in the wastes in such a state that they can be recycled, and gases containing carbon monoxide (CO) and hydrogen gas (H2) for use as synthesis gas for ammonia (NH3) or production of hydrogen gas. The wastes are gasified in a fluidized-bed reactor at a low temperature. Then, gaseous material and char produced in the fluidized-bed reactor are introduced into a high-temperature combustor, and gasified at a high temperature and ash content is converted into molten slag. After water scrubbing and a CO conversion reaction, the gas is separated into H2 and residual gas. The residual gas is then supplied to the fluidized-bed reactor as a fluidizing gas.

Abstract: A combustion method and apparatus in which combustible matter, e.g., waste matter, coal, etc., is gasified to produce a combustible gas containing a sufficiently large amount of combustible component to melt the ash by its own heat. A fluidized-bed furnace (2) has an approximately circular horizontal cross-sectional configuration. A moving bed (9), in which a fluidized medium settles and diffuses, is formed in the central portion of the furnace, and a fluidized bed (10), in which the fluidized medium is actively fluidized, is formed in the peripheral portion in the furnace. The fluidized medium is turned over to the upper part of the moving bed (9) from the upper part of the fluidized bed (10), thus circulating through the two beds. Combustible matter (11) is cast into the upper part of the moving bed (9) and gasified to form a combustible gas while circulating, together with the fluidized medium.

Abstract: The present invention relates to a swirling-type melting furnace for gasifying combustible wastes and/or coal, and a method of gasifying wastes by the swirling-type melting furnace. In the swirling-type melting furnace (5), gaseous materials supplied to a combustion chamber (6) form a swirling flow which includes an outer swirling flow primarily containing particulate combustibles and an inner swirling flow primarily containing gaseous combustibles. Oxygen is supplied through an inner wall of the combustion chamber (6) to the outer swirling flow primarily containing the particulate combustibles for thereby accelerating gasification of the particulate combustibles.

Abstract: The present invention relates to a swirling-type melting furnace for gasifying combustible wastes and/or coal, and a method of gasifying wastes by the swirling-type melting furnace. In the swirling-type melting furnace (5), gaseous materials supplied to a combustion chamber (6) form a swirling flow which includes an outer swirling flow primarily containing particulate combustibles and an inner swirling flow primarily containing gaseous combustibles. Oxygen is supplied through an inner wall of the combustion chamber (6) to the outer swirling flow primarily containing the particulate combustibles for thereby accelerating gasification of the particulate combustibles.

Abstract: A fluidized-bed reactor is suitable for uniformly oxidizing, i.e. combusting or gasifying, solid material containing combustible material and incombustible material, and for stably recovering thermal energy from the oxidized combustible material while smoothly discharging the incombustible material. The fluidized-bed reactor comprises a plurality of fluidizing gas diffusion devices disposed at a bottom of a fluidized-bed furnace for imparting different fluidizing speeds to the fluidized medium in a fluidized bed in the fluidized-bed furnace to form an upward flow of the fluidized medium in a fluidizing region with a substantially high fluidizing speed of the fluidized medium and a descending flow of the fluidized medium in a fluidizing region with a substantially low fluidizing speed of the fluidized medium. A plate-like thermal energy recovery device is disposed in the fluidizing region with the substantially low fluidizing speed of the fluidized medium and has a heat recovery surface extending vertically.

Abstract: A method of treating wastes includes partially combusting the wastes in a fluidized bed reactor at a relatively low temperature followed by separate gasification of gaseous material and char from the first gasification in a separate relatively high temperature reactor. This forms synthesis gas that is cooled, subjected to a conversion operation to produce hydrogen.

Abstract: A fluidized-bed thermal reaction apparatus burns or gasifies combustible matter containing incombustible components, so that deposition of incombustible components in a fluidized-bed furnace is prevented, and incombustible components are smoothly removed, thereby efficiently burning or gasifying the combustible matter. A weak diffusion plate, a strong diffusion plate, and an auxiliary diffusion plate, each have a large number of fluidizing gas feed holes. An incombustible component outlet is disposed between the auxiliary diffusion plate and the strong diffusion plate. A part of fluidizing gas is supplied from the incombustible component outlet, or the incombustible component outlet is provided to open horizontally. Thus, a continuous fluidized bed circulating stream is formed in the furnace bottom. The weak and auxiliary diffusion plates each has a downwardly inclined surface extending toward the incombustible component outlet.

Abstract: A method and apparatus for treating wastes by two-stage gasification recovers metals or ash content in the wastes in such a state that they can be recycled, and gases containing carbon monoxide (CO) and hydrogen gas (H.sub.2) for use as synthesis gas for ammonia (NH.sub.3) or production of hydrogen gas. The wastes are gasified in a fluidized-bed reactor at a low temperature. Then, gaseous material and char produced in the fluidized-bed reactor are introduced into a high-temperature combustor, and gasified at a high temperature and ash content is converted into molten slag. After water scrubbing and a CO conversion reaction, the gas is separated into H.sub.2 and residual gas. The residual gas is then supplied to the fluidized-bed reactor as a fluidizing gas.

Abstract: A pressurized internal circulating fluidized-bed boiler is incorporated in a combined-cycle electric generating system in which a fuel such as coal, petro coke or the like is combusted in a pressurized fluidized bed and an exhaust gas produced by the combusted fuel is introduced into a gas turbine. The pressurized internal circulating fluidized-bed boiler includes a pressure vessel, a combustor disposed in the pressure vessel and a main fluidized bed combustion chamber provided with an air diffusion device. A thermal energy recovery chamber is partitioned from the main combustion chamber by an inclined partition wall. A fluidized medium flows into and out of the main combustion chamber and the thermal energy recovery chamber. A free board is provided integrally above the main combustion chamber and the thermal energy recovery chamber so that combustion gas from the main combustion chamber and the thermal energy recovery chamber is mixed in the free board.