An air preheater (APH) temperature control system, including at least a first APH or combustion/secondary air bypass duct in metered communication with a combustion air inlet duct and a secondary air duct, adapted in use to bleed a portion of the combustion air as secondary air bypass from the air inlet duct upstream of the APH 100 for reintroduction downstream into the secondary air duct, and a flow control device for metering or controlling volumetric flow of the secondary air bypass and tempering primary air flow in use operative to maintain the flue gas outlet temperature at or above a desired minimum predetermined temperature for the incident flue gas volumetric flow exiting the APH alone or in conjunction with other tempering means maintaining mills outlet temperature within a safety range of T10.sub.MIN to T10.sub.MAX.

A method for continuous firing of combustion chambers with at least three regenerative burners, wherein a first regenerative burner cyclically in the combustion mode conveys supply air and a second regenerative burner in the exhaust mode conveys exhaust air. To avoid escape of hazardous process gases from the combustion chamber into the environment and high carbon monoxide emissions, and to provide energy-efficient firing operation despite use of compact regenerators, the volume flow of the supply or exhaust air through the first or second regenerative burner is reduced continuously and in counter-cycle mode to the volume flow of supply or exhaust air through a third regenerative burner at constant combustion chamber pressure until the first or second regenerative burner is flow-free.

A combustion system for a coal fired furnace having a windbox includes a source of a mixture of pulverized coal and air, and a splitter that receives the mixture and splits it into first and second mixed streams. A first nozzle receives the first mixed stream and discharges it into the furnace. A separator receives the second mixed stream and separates it into an air stream and a coal rich stream. An air conduit connected between the separator and the source of the mixture causes at least some of the air stream to be fed back into the mixture. A second nozzle receives the coal rich stream and discharges it into the furnace. A third nozzle receives support air from the windbox and discharges it into the furnace in a combustion supporting relationship with respect to the coal rich stream.

A control device of a hydrogen gas burner device sets a target flow rate of a hydrogen gas such that a flow rate of the hydrogen gas decreases as a temperature of the hydrogen gas becomes higher, based on the temperature of the hydrogen gas and a needed quantity of heat of the hydrogen gas during the combustion, sets a target flow speed such that the flow speed of the hydrogen gas released from a combustion nozzle via a flow speed regulator becomes a flow speed based on the target flow rate and the flow speed of the hydrogen gas increases as a value of the target flow rate decreases, controls the flow rate regulator such that the flow rate of the hydrogen gas reaches the target flow rate, and controls the flow speed regulator such that the flow speed of the hydrogen gas reaches the target flow speed.

A combustion-support-gas bypass line is provided to cause combustion support gas to bypass a preheater. A combustion-support-gas flow control damper is provided in the combustion-support-gas bypass line. An inlet temperature of a deduster is measured by a temperature sensor and the inlet temperature measured by the temperature sensor is inputted to a controller and is compared with a set temperature more than an acid dew-point preliminarily set in the controller. On the basis of a comparison result, an opening-degree control signal is outputted from the controller to the combustion-support-gas flow control damper so as to make the inlet temperature to a set temperature more than an acid dew-point.

The present disclosure relates to systems and methods that are useful for controlling one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants and methods of carrying out a power production method utilizing different fuel chemistries. Combustion of the different fuel mixtures can be controlled so that a defined set of combustion characteristics remains substantially constant across a range of different fuel chemistries.

A control device of a hydrogen gas burner device sets a target flow rate of a hydrogen gas such that a flow rate of the hydrogen gas decreases as a temperature of the hydrogen gas becomes higher, based on the temperature of the hydrogen gas and a needed quantity of heat of the hydrogen gas during the combustion, sets a target flow speed such that the flow speed of the hydrogen gas released from a combustion nozzle via a flow speed regulator becomes a flow speed based on the target flow rate and the flow speed of the hydrogen gas increases as a value of the target flow rate decreases, controls the flow rate regulator such that the flow rate of the hydrogen gas reaches the target flow rate, and controls the flow speed regulator such that the flow speed of the hydrogen gas reaches the target flow speed.

The present disclosure relates to systems and methods that are useful for controlling one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants and methods of carrying out a power production method utilizing different fuel chemistries. Combustion of the different fuel mixtures can be controlled so that a defined set of combustion characteristics remains substantially constant across a range of different fuel chemistries.

An air preheater (APH) temperature control system, including at least a first APH or combustion/secondary air bypass duct in metered communication with a combustion air inlet duct and a secondary air duct, adapted in use to bleed a portion of the combustion air as secondary air bypass from the air inlet duct upstream of the APH 100 for reintroduction downstream into the secondary air duct, and a flow control device for metering or controlling volumetric flow of the secondary air bypass and tempering primary air flow in use operative to maintain the flue gas outlet temperature at or above a desired minimum predetermined temperature for the incident flue gas volumetric flow exiting the APH alone or in conjunction with other tempering means maintaining mills outlet temperature within a safety range of T10.sub.MIN to T10.sub.MAX.

The present disclosure relates to systems and methods that are useful for controlling one or more aspects of a power production plant. More particularly, the disclosure relates to power production plants and methods of carrying out a power production method utilizing different fuel chemistries. Combustion of the different fuel mixtures can be controlled so that a defined set of combustion characteristics remains substantially constant across a range of different fuel chemistries.