Inferential pulverized fuel flow sensing and manipulation within a coal mill
AssigneeHoneywell International Inc.
InventorsVladimir Havlena, Jaroslav Pekar, Daniel Pachner
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Abstract
The subject mater herein relates to coal mills and, more particularly, inferential pulverized fuel flow sensing and manipulation within a coal mill. Various embodiments provide systems, methods, and software to manipulate a primary air flow rate and a coal feed rate into a coal mill to produce a target pulverized fuel flow. Some embodiments include sensing a differential pressure between two or more locations within a coal mill to estimate a recirculated load of coal at one or more stages within the coal mill.
Claims16
A computerized method of controlling a coal mill comprising:
- receiving, from a coal mill controller that executes on a computer, a target pulverized fuel flow PFt of pulverized coal to a combustion process;
- receiving a primary airflow rate PA of primary airflow into the coal mill;
- receiving a coal feed rate CF of coal being fed into the coal mill;
- receiving differential pressures dP sensed between each of a plurality of sets of two locations within a fuel path of the coal mill, each differential pressure dP sensed with respect to a powder stage of coal within the fuel path of the coal mill;
- determining a recirculated load RL of coal within the coal mill and a pulverized fuel flow PFa of coal from the coal mill as a function of the differential pressure dP measurements, the primary airflow rate PA, and the coal feed rate CF;
- estimating a mass of coal powder in each powder stage within the fuel path of the coal mill;
- and
- manipulating, through execution of instructions on at least one processor of the computer, CF and PA into the coal mill while receiving differential pressures dP sensed between the plurality of sets of two locations within a fuel path of the coal mill to approximate a pulverized fuel flow PFa to the combustion process, wherein the CF and PA are manipulated to cause the PFa to approach the PFt.
A non-transient computer-readable medium, with instructions stored thereon which when executed by a computer processor, cause a computer to control operation of a coal mill by performing actions comprising:
- receiving a target pulverized fuel flow PFt of pulverized coal to a combustion process;
- receiving a primary airflow rate PA of primary airflow into the coal mill;
- receiving a coal feed rate CF of coal being fed into the coal mill;
- receiving differential pressures dP sensed between each of a plurality of sets of two locations within a fuel path of the coal mill, each differential pressure dP sensed with respect to a powder stage of coal within the fuel path of the coal mill;
- determining a recirculated load of coal within the coal mill and a pulverized fuel flow PFa of coal from the coal mill as a function of the differential pressure dP measurements, the primary airflow rate PA, and the coal feed rate CF;
- estimating a mass of coal powder in each powder stage within the fuel path of the coal mill;
- manipulating CF and PA into the coal mill while receiving differential pressures dP sensed between the plurality of sets of two locations within a fuel path of the coal mill to approximate a pulverized fuel flow PFa to the combustion process, wherein the CF and PA are manipulated through issuance of at least one command to at least one of an airflow controller and a coal feed controller to cause the PFa to approach the PFt.
Dependencies are inferred from the claim text.