US 10,537,845 B2 · Ammonia-adding system for ammonia-based desulfurization device

Abstract

Ammonia-adding apparatus and methods for ammonia-based desulfurization use multi-stage control, calculate a theoretical amount of ammonia based on gas amounts provided by an inlet continuous emission monitoring system (CEMS) and an outlet CEMS of the ammonia-based desulfurization device or associated gas amounts, a SO2 concentration provided by the inlet CEMS, and a predetermined SO2 concentration of the outlet CEMS. The apparatus and methods calculate a corrected theoretical amount of ammonia using half of the ratio of the actual amount of added ammonia to the actual amount of removed sulfur dioxide as a correction coefficient for the theoretical amount of ammonia; add an ammonia absorbent equivalent to the corrected theoretical amount of ammonia to the ammonia-based desulfurization device through an ammonia metering means and an ammonia control valve, and automatically control the actual ammonia flow rate based on the actual SO2 concentration and a change trend provided by the outlet CEMS.

Claims30

Dependent claims

Apparatus for adding ammonia to an absorption solution in a flue-gas desulfurization system, the apparatus comprising:

adding an emission monitoring system configured to provide a measure of an output sulfur dioxide characteristic;
valves configured to:
add ammonia to the absorption solution at a base rate that is proportional to:
a) a target sulfur dioxide removal rate defined as a difference between:
1) a product of:
a gas flow rate corresponding to an inlet of the desulfurization system and an inlet SO2 concentration;
and
2) a product of:
a gas flow rate corresponding to an outlet of the desulfurization system and a predetermined SO2 outlet concentration;
and
b) a correction coefficient that includes a ratio of cumulative ammonia added to cumulative sulfur dioxide removed;
and,
then, control ammonia addition to the absorption solution to a second rate based on the measure of the output sulfur dioxide characteristic;
and
a distributed control system configured to:
receive a flue gas inlet flow rate corresponding to the inlet of the desulfurization system;
and
calculate an amount of required ammonia based, at least partly, on the flue gas inlet flow rate,
wherein the gas flow rate corresponding to the inlet is evaluated as the flue gas inlet flow rate.

16 more elements

Apparatus for adding ammonia to an absorption solution in a flue-gas desulfurization system, the apparatus comprising:

an emission monitoring system configured to provide a measure of an output sulfur dioxide characteristic;
valves configured to:
add ammonia to the absorption solution at a base rate that is proportional to:
a) a target sulfur dioxide removal rate defined as a difference between:
1) a product of:
a gas flow rate corresponding to an inlet of the desulfurization system and an inlet SO2 concentration;
and
2) a product of:
a gas flow rate corresponding to an outlet of the desulfurization system and a predetermined SO2 outlet concentration;
and
b) a correction coefficient that includes a ratio of cumulative ammonia added to cumulative sulfur dioxide removed;
and,
then, control ammonia addition to the absorption solution to a second rate based on the measure of the output sulfur dioxide characteristic;
and
a distributed control system configured to:
receive a flue gas outlet flow rate corresponding to the outlet of the desulfurization system;
and
calculate an amount of required ammonia based, at least partly, on the flue gas outlet flow rate,
wherein the gas flow rate corresponding to the outlet is evaluated as the flue gas outlet flow rate.

16 more elements

Dependencies are inferred from the claim text.

Ammonia-adding system for ammonia-based desulfurization device

Life of this patent

Ammonia-adding system for ammonia-based desulfurization device

Life of this patent

Abstract

Claims30