Predictive emissions monitor systems and methods

Patent metadata

Field	Value
Publication number	US-9808762-B2
Application number	US-201514694821-A
Country	US
Kind code	B2
Filing date	Apr 23, 2015
Priority date	Apr 23, 2015
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

One embodiment of the present disclosure describes an industrial system, which includes a control system with a predictive emissions monitoring system that facilitates determining a chemical level output from a selective catalytic reduction unit that reduces the chemical level in gaseous emissions produced by a combustion source using a selective catalytic reduction model. The control system tunes the selective catalytic reduction model by determining tuning parameters based at least in part on vendor information and tuning data determined via a tuning sequence. The tuning sequence includes operating the combustion source at a plurality of load levels, injecting a reactant into received gaseous emissions at each of the plurality of load levels in accordance with an injection rate provided in the vendor information; and determining an input chemical level to and an output chemical level from the selective catalytic reduction unit at each of the plurality of load levels.

First claim

The invention claimed is:

1. A method for operating a selective catalytic reduction unit, comprising:
tuning, using a control system, a selective catalytic reduction model to the selective catalytic reduction unit to describe expected relationship between operational parameters of the selective catalytic reduction unit and level of nitrogen oxide output from the selective catalytic reduction unit, wherein tuning the selective catalytic reduction model comprises:
instructing a combustion source that produces gaseous emissions comprising nitrogen oxide to operate at each of a plurality of load levels;
instructing the selective catalytic reduction unit to inject a reactant into the gaseous emissions output from the combustion source while operating at each of the plurality of load levels in accordance with an injection rate provided in vendor information;
determining an input nitrogen oxide level to and an output nitrogen oxide level from the selective catalytic reduction unit at each of the plurality of load levels; and
determining tuning parameters of the selective catalytic reduction model based at least in part on the input nitrogen oxide level, the output nitrogen oxide level, and the injection rate of the reactant at each of the plurality of load levels; and

after tuning the selective catalytic reduction model to the selective catalytic reduction unit:
predicting, using the control system, the level of nitrogen oxide expected to be output from the selective catalytic reduction unit based at least in part on the operational parameters of the selective catalytic reduction unit and the selective catalytic reduction model; and

controlling, using the control system, operation of the selective catalytic reduction unit based at least in part on the level of nitrogen oxide expected to be output from the selective catalytic reduction unit;
wherein tuning the selective catalytic reduction model comprises removing a sensor used to determine the output nitrogen oxide level at each of the plurality of load levels after determining the tuning parameters of the selective catalytic reduction model.

2. The method of claim 1 , wherein the vendor information indicates:
a constant injection rate of the reactant based on load level of the combustion source;
operational parameter ranges in which the selective catalytic reduction unit is expected to operate; and
a nitrogen oxide reduction rate expected to occur when the selective catalytic reduction unit injects the reactant using the constant injection rate and operates within the operational parameter ranges.

3. The method of claim 1 , wherein:
determining the input nitrogen oxide level at each of the plurality of load levels comprises polling a first sensor coupled between the combustion source and the selective catalytic reduction unit; and
determining the output nitrogen oxide level at each of the plurality of load levels comprises polling a second sensor coupled to an exhaust of the selective catalytic reduction unit, wherein the second sensor is a temporary sensor.

4. The method of claim 1 , wherein instructing the combustion source to operate at the plurality of load levels comprises instructing the combustion source to operate at a first load level and, subsequently, instructing the combustion source to operate at a second load level different from the first load level.

5. The method of claim 1 , wherein controlling operation of the selective catalytic reduction unit comprises instructing the selective catalytic reduction unit to adjust the injection rate of the reactant into the gaseous emissions received from the combustion source.

6. The method of claim 1 , wherein predicting the level of nitrogen oxide expected to be output from the selective catalytic reduction unit comprises:
determining the operational parameters of the selective catalytic reduction unit; and
inputting the operational parameters into the selective catalytic reduction model after the tuning parameters are determined.

7. The method of claim 1 , wherein the reactant comprises ammonia or urea.

8. A method for utilizing a selective catalytic reduction model, comprising:
tuning the selective catalytic reduction model to a selective catalytic reduction unit configured to process nitrogen oxide produced by a combustion source, wherein tuning the selective catalytic reduction model comprises:
instructing the combustion source to operate at a plurality of load levels;
determining an input nitrogen oxide level to and an output nitrogen oxide level from the selective catalytic reduction unit at each of the plurality of load levels;
determining an injection rate of a reactant in the selective catalytic reduction unit at each of the plurality of load levels;
determining tuning parameters of the selective catalytic reduction model based at least in part on the input nitrogen oxide level, the output nitrogen oxide level, and the injection rate of the reactant determined at each of the plurality of load levels; and
removing a sensor used to determine the output nitrogen oxide level at each of the plurality of load levels after determining the tuning parameters of the selective catalytic reduction model; and

controlling, using a control system, operation of the selective catalytic reduction unit based at least in part on amount of nitrogen oxide released from the selective catalytic reduction unit determined using the selective catalytic reduction model.

9. The method of claim 8 , wherein instructing the combustion source to operate at the plurality of load levels comprises instructing the combustion source to operate at a first load level and, subsequently, instructing the combustion source to operate at a second load level different from the first load level.

10. The method of claim 8 , wherein controlling operation of the selective catalytic reduction unit comprises instructing the selective catalytic reduction unit to adjust the injection rate of the reactant into gaseous emissions received from the combustion source.

11. The method of claim 8 , wherein controlling operation of the selective catalytic reduction unit comprises: predicting the level of nitrogen oxide expected to be output from the selective catalytic reduction unit by: determining operational parameters of the selective catalytic reduction unit; and inputting the operational parameters into the selective catalytic reduction model after the tuning parameters are determined; and controlling, using a control system, operation of the selective catalytic reduction unit based the level of nitrogen oxide predicted to be output from the selective catalytic reduction unit.

Assignees

• Rockwell Automation Tech Inc

Inventors

• Hayes Iv Walter Edgar
• Smith Keith Alex
• Boe Eugene
• Yieh Dennis Tzyy-nian

Classifications

• B01D2251/2067

  Urea · CPC title

• B01D53/8696 Primary

  Controlling the catalytic process · CPC title

• B01D2251/2062

  Ammonia · CPC title

• B01D53/90

  Injecting reactants · CPC title

• B01D2258/0283

  Flue gases · CPC title