Method for obtaining information on quality of combustion of a liquor in a chemical recovery boiler and a method for controlling a chemical recovery boiler

Patent metadata

Field	Value
Publication number	US-12039239-B2
Application number	US-202117183962-A
Country	US
Kind code	B2
Filing date	Feb 24, 2021
Priority date	Mar 6, 2020
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

A method for obtaining information on quality of combustion of a liquor in a chemical recovery boiler. The method comprises entering a value of a first input parameter to a computational model configured to determine, based on the value of the first input parameter, a value of the quality of combustion of the liquor in the chemical recovery boiler, and at a first time, running the computational model to obtain a first modelling result. The method comprises measuring, from the chemical recovery boiler a value indicative of carryover to obtain a measurement result; comparing the first modelling result with [a] the measurement result or [b] a result derived from the measurement result, to obtain a primary comparison result; and adjusting the value of the first input parameter based on the primary comparison result to obtain an adjusted value of the first input parameter. The method comprises entering the adjusted value of the first input parameter to the computational model, and at a second time, running the computational model to obtain the information on quality of combustion of the liquor in the chemical recovery boiler.

First claim

The invention claimed is:

1. A method for controlling a chemical recovery boiler, the method comprising:
entering a value of a first input parameter to a computational model configured to determine, based on the value of the first input parameter, a value of the quality of combustion of liquor in the chemical recovery boiler,
at a first time, running the computational model to obtain a first modelling result,
measuring, from the chemical recovery boiler, a value indicative of carryover to obtain a measurement result,
comparing the first modelling result with [a] the measurement result or [b] a result derived from the measurement result, to obtain a primary comparison result based on the value indicative of carryover,
adjusting the value of the first input parameter based on the primary comparison result to obtain an adjusted value of the first input parameter,
entering the adjusted value of the first input parameter to the computational model,
at a second time, running the computational model with the adjusted value of the first input parameter to obtain information on quality of combustion of the liquor in the chemical recovery boiler, and
controlling, in the chemical recovery boiler, at least one parameter selected from the group consisting of:
a temperature of black liquor or brown liquor that is fed into the furnace of the chemical recovery boiler, and
a pressure of the black or brown liquor that is fed into the furnace of the chemical recovery boiler,

using the information on the quality of combustion of the liquor in the chemical recovery boiler.

2. The method of claim 1 , wherein the value indicative of carryover is measured at least one of:
directly with a carryover detector, or
by measuring one or both of [i] a size of a char bed, and [ii] a temperature or a temperature profile at a location that is downstream from a liquor injection gun of the chemical recovery boiler, the liquor injection gun being configured to feed the liquor that is burnt into the chemical recovery boiler, and upstream from a superheater of the chemical recovery boiler, in the direction of flow of flue gases in the chemical recovery boiler.

3. The method of claim 1 , wherein:
the computational model is based on fluid dynamics or
the computational model is a reduced model.

4. The method of claim 1 , wherein the value of the first input parameter comprises one or both of:
a value of a model particle size of black or brown liquor within the chemical recovery boiler and/or
a value of a model deposit thickness on a superheater of the chemical recovery boiler.

5. The method of claim 1 , wherein:
the computational model comprises at least a first part describing a furnace area of the chemical recovery boiler.

6. The method of claim 1 , wherein:
the computational model comprises a part describing a furnace area of the chemical recovery boiler; the method comprising:
entering also a value of a second input parameter to the computational model, wherein the value of the second input parameter comprises value(s) of one or more than one of:
a first flow of combustion air through a first air inlet into the chemical recovery boiler and a second flow of combustion air through a second air inlet into the chemical recovery boiler,
an effective cross sectional area of the first air inlet and an effective cross sectional area of the second air inlet,
a temperature of combustion air at a first vertical level and a temperature of combustion air at a second vertical level,
a first flow of black or brown liquor into the chemical recovery boiler through a first injection gun,
a second flow of black or brown liquor into the chemical recovery boiler through a second injection gun,
a pressure in a drum of the chemical recovery boiler,
a dry matter content of the black or brown liquor that is fed into the chemical recovery boiler,
a chemical content of dry matter of the black or brown liquor that is fed into the chemical recovery boiler,
a heat value of the black or brown liquor that is fed into the chemical recovery boiler,
a temperature of the black or brown liquor that is fed into the chemical recovery boiler,
a pressure of the black or brown liquor that is fed into the chemical recovery boiler,
a first angle of a first injection gun that feeds the black or brown liquor into the chemical recovery boiler,
a second angle of a second injection gun that feeds the black or brown liquor into the chemical recovery boiler,
a flow of concentrated non-condensable gases into the furnace of the chemical recovery boiler,
a flow of another auxiliary fuel into the furnace of the chemical recovery boiler, or
an oxygen content of flue gases.

7. The method of claim 6 , comprising:
defining a first control procedure,
adjusting the value of the second input parameter according to the first control procedure to obtain a first adjusted value of the second input parameter,
entering the first adjusted value of the second input parameter to the computational model,
thereafter, running the computational model to obtain secondary information on quality of combustion of the liquor in the chemical recovery boiler, and
controlling the chemical recovery boiler using the secondary information on quality of combustion of the liquor in the chemical recovery boiler.

8. The method of claim 7 , comprising:
defining a second control procedure,
adjusting the value of the second input parameter according to the second control procedure to obtain a second adjusted value of the second input parameter,
entering the second adjusted value of the second input parameter to the computational model,
thereafter, running the computational model to obtain tertiary information on quality of combustion of the liquor in the chemical recovery boiler, and
controlling the chemical recovery boiler using the secondary and tertiary information on quality of combustion of the liquor in the chemical recovery boiler.

9. The method of claim 1 , wherein:
the computational model comprises a first part describing a furnace area of the chemical recovery boiler and second part describing a superheater area of the chemical recovery boiler; the method comprising:
entering also a value of a second input parameter to the computational model, wherein the value of the second input parameter comprises value(s) of one or more than one of:
a first flow of combustion air through a first air inlet into the chemical recovery boiler and a second flow of combustion air through a second air inlet into the chemical recovery boiler,
an effective cross sectional area of the first air inlet and an effective cross sectional area of the second air inlet,
a temperature of combustion air at a first vertical level and a temperature of combustion air at a second vertical level,
a first flow of black or brown liquor into the chemical recovery boiler through a first injection gun,
a second flow of black or brown liquor into the chemical recovery boiler through a second injection gun,
a pressure in a drum of the chemical recovery boiler,
a dry matter content of the black or brown liquor that is fed into the chemical recovery boiler,
a chemical content of dry matter of the black or brown liquor that is fed into the chemical recovery boiler,
a heat value of the black or brown liquor that is fed into the chemical recovery boiler,
a temperature of the black or brown liquor that is fed into the chemical recovery boiler,
a pressure of the black or brown liquor that is fed into the chemical recovery boiler,
a first angle of a first injection gun that feeds the black or brown liquor into the chemical recovery boiler,
a second angle of a second injection gun that feeds the black or brow

Assignees

• Valmet Automation Oy

Inventors

• Mansikkasalo Jarmo

Classifications

• G06F30/28 Primary

  using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD] · CPC title

• G06F30/27

  using machine learning, e.g. artificial intelligence, neural networks, support vector machines [SVM] or training a model · CPC title

• F23G5/50 Primary

  Control or safety arrangements · CPC title

• D21C11/0057

  Oxidation of liquors, e.g. in order to reduce the losses of sulfur compounds, followed by evaporation or combustion if the liquor in question is a black liquor (deodorisation of gases D21C11/08; combustion D21C11/12, D21C11/14) · CPC title

• F23G7/04

  of waste liquors, e.g. sulfite liquors · CPC title