CN113198294B - Seawater desulfurization control method and equipment - Google Patents

Seawater desulfurization control method and equipment Download PDF

Info

Publication number
CN113198294B
CN113198294B CN202110560604.1A CN202110560604A CN113198294B CN 113198294 B CN113198294 B CN 113198294B CN 202110560604 A CN202110560604 A CN 202110560604A CN 113198294 B CN113198294 B CN 113198294B
Authority
CN
China
Prior art keywords
absorption tower
preset
seawater
concentration
machine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110560604.1A
Other languages
Chinese (zh)
Other versions
CN113198294A (en
Inventor
陈筑
王海彬
王建
罗云岭
李杨
白云峰
徐仁博
韩旭
叶鹏飞
李前胜
姜彦辰
郭效源
邓洪浩
王志浩
郑添全
王宁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dalian Power Plant of Huaneng International Power Co Ltd
Original Assignee
Dalian Power Plant of Huaneng International Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dalian Power Plant of Huaneng International Power Co Ltd filed Critical Dalian Power Plant of Huaneng International Power Co Ltd
Priority to CN202110560604.1A priority Critical patent/CN113198294B/en
Publication of CN113198294A publication Critical patent/CN113198294A/en
Application granted granted Critical
Publication of CN113198294B publication Critical patent/CN113198294B/en
Priority to JP2022066631A priority patent/JP2022179349A/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1406—Multiple stage absorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1412—Controlling the absorption process
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1456—Removing acid components
    • B01D53/1481—Removing sulfur dioxide or sulfur trioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/18—Absorbing units; Liquid distributors therefor
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D11/00—Control of flow ratio
    • G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
    • G05D11/13—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means
    • G05D11/131—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components
    • G05D11/132—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components by controlling the flow of the individual components
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/10—Inorganic absorbents
    • B01D2252/103—Water
    • B01D2252/1035—Sea water

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Treating Waste Gases (AREA)

Abstract

The inventionDisclosed are a seawater desulfurization control method and apparatus, the method comprising: one of the first absorption tower and the second absorption tower is used as a local absorption tower, and the other one is used as an on-machine absorption tower; the first absorption tower and the second absorption tower share a set of desulfurization seawater pressurization system. If the first preset condition is met, fully opening a seawater inlet regulating valve of the absorption tower of the machine; if the second preset condition is met, increasing the opening of a seawater inlet regulating valve of the absorption tower of the machine based on a first preset speed; if a third preset condition is met and the first preset condition or the second preset condition is not met, reducing the opening degree of a seawater inlet regulating valve of the absorption tower of the machine based on a second preset speed; if the fourth preset condition is met, the opening degree of a seawater inlet regulating valve of the absorption tower of the machine is increased based on the second preset rate, SO that the clean flue gas outlet SO of the absorption tower is ensured2On the basis of the concentration not exceeding the standard and the minimum inlet seawater flow, the seawater inlet regulating valve is prevented from being manually regulated, and the reliability of the seawater desulfurization system is further improved.

Description

Seawater desulfurization control method and equipment
Technical Field
The application relates to the technical field of environmental protection of thermal power plants, in particular to a seawater desulfurization control method and equipment.
Background
The seawater desulfurization process uses seawater as an absorbent, adopts a proper liquid-gas ratio to wash flue gas in an absorption tower, has low investment and operation cost, and is widely adopted by a large number of coastal power plants.
In the prior art, an operator controls the clean flue gas outlet SO of the absorption tower by manually controlling the seawater inlet regulating valve of the absorption tower2Concentration and minimum seawater flow at the inlet of the absorption tower, and the adjusting mode has the following defects:
(1) operator manually controls clean flue gas outlet SO2The concentration increases the monitoring pressure of operators, and meanwhile, the possibility of untimely adjustment exists, and the risk of environmental protection exceeding standards is increased.
(2) The minimum inlet seawater flow cannot be ensured in real time due to the fact that the inlet seawater flow of the absorption tower is manually adjusted. If the spraying density is uneven, the water holding capacity of the filler is different, the filler with the small water holding capacity is light in weight and small in resistance, a large amount of smoke is easy to pass through a weak area, so that the filler is dispersed by the smoke, the filler layer is leaky or uneven, and the desulfurization efficiency is reduced.
The throttling loss of the inlet regulating valve increases the power consumption of the plant.
Therefore, how to ensureClean flue gas outlet SO of absorption tower2The method avoids manual adjustment of a seawater inlet adjusting valve on the basis of the concentration not exceeding the standard and the minimum inlet seawater flow, further improves the reliability of a seawater desulfurization system, and is a technical problem to be solved at present.
Disclosure of Invention
The invention provides a seawater desulfurization control method, which is used for solving the technical problem of low reliability of a seawater desulfurization system caused by manual adjustment of a seawater inlet adjusting valve of each absorption tower in the prior art.
The method is applied to a seawater desulfurization system, the seawater desulfurization system comprises a first absorption tower, a second absorption tower and at least one seawater booster pump which can be controlled in a variable frequency mode, the first absorption tower is connected with a first unit through an original flue, the second absorption tower is connected with a second unit through an original flue, an outlet of the seawater booster pump is respectively connected with the first absorption tower and the second absorption tower through a seawater inlet adjusting valve of the first absorption tower and a seawater inlet adjusting valve of the second absorption tower, and the method comprises the following steps:
a seawater desulfurization control method is applied to a seawater desulfurization system and is characterized by comprising the following steps:
the selection module takes one of the first absorption tower and the second absorption tower as a local absorption tower and takes the other one as an on-line absorption tower;
wherein the local SO of the clean flue gas outlet of the local absorption tower is set2A near-machine SO with the concentration of Pa and the set clean smoke outlet of the near-machine absorption tower2Setting the opening of a seawater inlet regulating valve of the absorption tower of the machine as Ka, setting the opening of a seawater inlet regulating valve of the absorption tower of the machine as Kb, and setting the inlet seawater flow of the absorption tower of the machine as Qa;
a plurality of preset SOs are set in the selected module2Concentration of first predetermined SO2Concentration P1, second predetermined SO2Concentration P2 and third predetermined SO2A concentration P3, and multiple preset seawater flow rates including a first preset seawater flow rate V1 and a second preset seawater flow rateV2 and a third preset seawater flow rate V3;
the selected module is provided with a plurality of preset conditions, and when the system runs, the selected module can increase or decrease the opening Ka of the seawater inlet regulating valve of the absorption tower of the machine according to the preset conditions actually met by the system:
if the system meets a first preset condition, fully opening a seawater inlet regulating valve of the absorption tower of the machine;
if the system meets a second preset condition, increasing the opening Ka of a seawater inlet regulating valve of the absorption tower of the machine based on a first preset seawater flow rate V1;
if the system meets a third preset condition and does not meet the first preset condition or the second preset condition, reducing the opening Ka of a seawater inlet regulating valve of the absorption tower of the machine based on a second preset seawater flow rate V2;
if the system meets a fourth preset condition, increasing the opening Ka of a seawater inlet regulating valve of the absorption tower of the machine based on the second preset seawater flow rate V2;
if the system meets a fifth preset condition and does not meet the third preset condition or the fourth preset condition, increasing the opening Ka of a seawater inlet regulating valve of the absorption tower of the system based on a third preset speed V3;
wherein the first preset condition is that the machine SO of the clean flue gas outlet of the machine absorption tower2The concentration Pa is greater than the first preset SO2Concentration P1, the second preset condition is that the inlet seawater flow Qa of the local absorption tower is lower than the minimum flow Qmin corresponding to the current flue gas load, and the third preset condition is that the on-line SO at the clean flue gas outlet of the on-line absorption tower is close to the on-line SO2The concentration Pb is greater than the first preset SO2Concentration P1 and ratio of the local SO2The concentration Pa is higher than at least a second preset concentration P2, and the fourth preset condition is that the machine SO is used2Concentration Pa is higher than that of the temporary SO2The concentration Pb is higher than at least a third preset concentration P3, and the fifth preset condition is that the opening degree of a seawater inlet regulating valve of the absorption tower is smaller than 100%.
Furthermore, the opening degree of the seawater inlet regulating valves of the temporary absorption towers is set to be Kb, and the selected module is also provided with a first preset opening degree Kb1 of the seawater inlet regulating valve of the temporary absorption tower, a second preset opening degree Kb2 of the seawater inlet regulating valve of the temporary absorption tower, and a first preset SO2Concentration difference Δ Pa1 and second predetermined SO2The concentration difference Δ Pa 2;
when the system meets a first preset condition, a selection module calculates a local SO of a clean flue gas outlet of the local absorption tower2Concentration Pa and first predetermined SO2Setting the difference delta Pa of the concentration P1 as Pa-P1, comparing the delta Pa with delta Pa1 and delta Pa2 respectively by a selection module, determining the opening Kb of a seawater inlet regulating valve of the temporary absorption tower according to the comparison result,
when the delta Pa is less than or equal to the delta Pa1, the selected module sets the opening of a seawater inlet regulating valve of the absorber tower adjacent to the machine to be 0;
when the delta Pa1 is smaller than or equal to the delta Pa2, the selected module sets the opening degree of a seawater inlet regulating valve of the on-machine absorption tower to Kb 1;
when Δ Pa > [ Δ Pa2, the selection module sets the opening of the seawater inlet regulating valve of the mechanical absorption tower to Kb 2.
Further, a first preset adjustment coefficient alpha 1 of the first preset seawater flow and a first preset adjustment coefficient alpha 2 of the first preset seawater flow are also arranged in the selected module;
when the system meets a second preset condition, the selection module selects a corresponding preset seawater flow rate adjustment coefficient according to the opening degree of the seawater inlet adjustment valve of the temporary absorption tower to adjust the first preset seawater flow rate V1, the adjusted first preset seawater flow rate is set to be V1',
when the opening degree of a seawater inlet regulating valve of the temporary absorption tower is 0, the selected module sets V1 to V1;
when the opening degree of a seawater inlet regulating valve of the temporary absorption tower is Kb1, the selected module sets V1 ═ V1 × α 1;
when the opening degree of the seawater inlet regulating valve of the absorption tower is Kb2, the selected module sets V1 ═ V1 × α 2.
Further, when the system meets a third preset condition and the system does not meet the first preset condition or the second preset condition, the selection module calculates a computer-on-air SO2Concentration Pb and the first predetermined SO2The difference value of the concentration P1 is delta Pb, the delta Pb is set to be Pb-P1, and the selected module is further provided with a first preset temporary SO2Concentration Pb and the first predetermined SO2The difference in concentration P1 is Δ Pb 1;
when delta Pb is less than delta Pb1, the selected module does not adjust the opening Kb of the seawater inlet adjusting valve of the absorption tower approaching the machine;
when the delta Pb is not less than the delta Pb1, the selected module reduces the opening Kb of the seawater inlet regulating valve of the on-machine absorption tower;
furthermore, a first preset local absorption tower seawater inlet regulating valve opening degree Ka1, a second preset local absorption tower seawater inlet regulating valve opening degree Ka2, a third preset local absorption tower seawater inlet regulating valve opening degree Ka3, a second preset seawater flow first preset adjusting coefficient beta 1, a second preset seawater flow second preset adjusting coefficient beta 2 and a second preset seawater flow third preset adjusting coefficient beta 3 are further arranged in the selected module;
when the system meets a fourth preset condition, the selection module compares the opening degree Ka of the seawater inlet regulating valve of the absorption tower with the opening degree of the seawater inlet regulating valve of each preset absorption tower in sequence and selects a corresponding second preset seawater flow preset regulating coefficient according to the comparison result to regulate the second preset seawater flow rate, the regulated second preset seawater flow rate is set to be V2',
when Ka ≦ Ka1, the selected module sets V2 ═ V2;
when Ka1 < Ka ≦ Ka2, the selected module sets V2 ═ V2 × β 1;
when Ka2 < Ka ≦ Ka3, the selected module sets V2 ═ V2 × β 2;
when Ka > Ka3, the selected module sets V2 ═ V2 × β 3.
Further, the first preset SO2The concentration P1 is greater than the second preset SO2Concentration P2, the second predetermined SO2The concentration P2 is greater than the third preset SO2Concentration P3, the first preset seawater flow rate V1 being less than the third preset seawater flow rate V3, the third preset seawater flow rate V3 being less than the second preset seawater flow rate V2.
Further, the frequency converter of the seawater booster pump is controlled based on a cascade PID and feedforward control strategy, and the cascade PID and feedforward control strategy comprises controlling the local SO based on a main PID controller2Concentration and the on-line SO2Concentration, controlling inlet seawater flow of the local absorption tower and the temporary absorption tower based on a secondary PID controller, wherein the feed-forward signal comprises raw flue gas SO of the local absorption tower2The product of the concentration and the total coal amount or the smoke gas amount of the corresponding unit, and the raw smoke gas SO of the on-machine absorption tower2The concentration is multiplied by the total coal or flue gas of the corresponding unit.
Further, the input signals of the cascade PID and feedforward control strategy comprise a local input signal and a temporary input signal, and the local input signal comprises the inlet seawater flow and the raw flue gas SO of the local absorption tower2Concentration, the on-line input signal comprises the inlet seawater flow and the raw flue gas SO of the on-line absorption tower2Concentration, the method further comprising:
if the manual selection of the local priority mode is detected, or the seawater inlet regulating valve of the on-machine absorption tower is switched to the manual mode, or the MFT signal of the unit corresponding to the on-machine absorption tower is switched to the local priority mode;
if the manual selection of the on-line priority mode is detected, or the seawater inlet regulating valve of the absorption tower of the machine is switched to the manual mode, or the MFT signal of the unit corresponding to the absorption tower of the machine is switched to the on-line priority mode;
if the manual selection of the coordination control mode is detected, switching to a dual-computer coordination control mode;
the local priority mode includes that the machine-approaching input signal automatically tracks the local input signal or the machine-approaching input signal is forced to be 0, the machine-approaching priority mode includes that the local input signal automatically tracks the machine-approaching input signal or the local input signal is forced to be 0, and the dual-machine coordination control mode includes that the local input signal and the machine-approaching input signal are not processed.
Further, a seawater desulfurization control apparatus of a seawater desulfurization control method includes a first absorption tower, a second absorption tower, and at least one variable-frequency-controlled seawater booster pump, where the first absorption tower is connected to a first unit through an original flue, the second absorption tower is connected to a second unit through an original flue, an outlet of the seawater booster pump is connected to the first absorption tower and the second absorption tower respectively through a seawater inlet regulating valve of the first absorption tower and a seawater inlet regulating valve of the second absorption tower, and the apparatus includes:
a selection module, configured to use one of the first absorption tower and the second absorption tower as a local absorption tower, and use the other as an on-machine absorption tower;
the first adjusting module is used for fully opening a seawater inlet adjusting valve of the absorption tower of the machine if a first preset condition is met;
the second adjusting module is used for increasing the opening of the seawater inlet adjusting valve of the absorption tower of the machine based on a first preset speed if a second preset condition is met;
the third adjusting module is used for reducing the opening of a seawater inlet adjusting valve of the absorption tower of the machine based on a second preset speed if a third preset condition is met and the first preset condition or the second preset condition is not met;
the fourth adjusting module is used for increasing the opening of the seawater inlet adjusting valve of the absorption tower of the machine based on the second preset speed if a fourth preset condition is met;
wherein the first preset condition is specifically the local SO of the clean flue gas outlet of the local absorption tower2The concentration is greater than a first preset concentration, and the second preset condition is that the flow of the seawater at the inlet of the absorption tower of the machine is lower than the current smokeThe third preset condition is specifically that the machine-approaching SO at the clean flue gas outlet of the machine-approaching absorption tower is close to the machine2The concentration is greater than the first preset concentration and is greater than the local SO2The concentration is higher than at least a second preset concentration, and the fourth preset condition is specifically that the machine SO2Concentration ratio of the said in-situ SO2The concentration is higher by at least a third preset concentration.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a seawater desulfurization control method and equipment, which are applied to a seawater desulfurization system comprising a first absorption tower, a second absorption tower and at least one variable-frequency-controlled seawater booster pump, wherein the method comprises the following steps: one of the first absorption tower and the second absorption tower is used as a local absorption tower, and the other one is used as an on-machine absorption tower; if the first preset condition is met, fully opening a seawater inlet regulating valve of the absorption tower of the machine; if the second preset condition is met, increasing the opening of a seawater inlet regulating valve of the absorption tower of the machine based on a first preset speed; if a third preset condition is met and the first preset condition or the second preset condition is not met, reducing the opening degree of a seawater inlet regulating valve of the absorption tower of the machine based on a second preset speed; if the fourth preset condition is met, the opening degree of a seawater inlet regulating valve of the absorption tower of the machine is increased based on the second preset rate, SO that the clean flue gas outlet SO of the absorption tower is ensured2On the basis of the concentration not exceeding the standard and the minimum inlet seawater flow, the seawater inlet regulating valve is prevented from being manually regulated, so that the reliability of the seawater desulfurization system is improved, and the monitoring pressure of operators is reduced; the seawater inlet regulating valve of at least one absorption tower is fully opened, so that the throttling loss of the seawater inlet regulating valve is reduced, and the power consumption of a plant is reduced; and the frequency converter of the seawater booster pump is controlled based on a cascade PID and feedforward control strategy, so that the frequency of the seawater booster pump is reduced as much as possible, and the station power consumption of the seawater booster pump is reduced.
Furthermore, the selected module is provided with a plurality of seawater inlet regulating valves of the absorption tower approaching the machine, the opening degree of the seawater inlet regulating valves is Kb, and when the system meets a first preset condition, the seawater inlet regulating valves are selectedThe module calculates the local SO of the clean flue gas outlet of the local absorption tower2Concentration Pa and first predetermined SO2Comparing the difference delta Pa of the concentration P1 with delta Pa1 and delta Pa2 respectively, determining the opening degree Kb of a seawater inlet regulating valve of the temporary absorption tower according to the comparison result, and determining the opening degree Kb of a clean flue gas outlet of the temporary absorption tower according to the clean flue gas outlet of the temporary absorption tower2Concentration and first predetermined SO2The opening degree of the seawater inlet regulating valve of the temporary absorption tower is regulated to a corresponding value by the concentration difference value, SO that the local SO of the clean smoke outlet of the local absorption tower can be effectively avoided when the system runs2Too high a concentration results in a system that cannot efficiently process SO2The system has the advantages that the power consumption of the seawater booster pump is further reduced, and meanwhile, the reliability of the system is effectively improved.
Further, a first preset seawater flow first preset adjustment coefficient alpha 1 and a first preset seawater flow first preset adjustment coefficient alpha 2 are further arranged in the selection module, when the system meets a second preset condition, the selection module selects a corresponding preset seawater flow adjustment coefficient according to the opening degree of the seawater inlet adjusting valve of the on-machine absorption tower to adjust the first preset seawater flow rate V1, and the corresponding first preset seawater flow preset adjustment coefficient is selected according to the opening degree of the seawater inlet adjusting valve of the on-machine absorption tower to adjust the first preset seawater flow rate, SO that the system can ensure that the clean flue gas outlet of the on-machine absorption tower discharges SO meeting the emission standard under the condition that the opening degree of the seawater inlet adjusting valve of the on-machine absorption tower is different2Thereby further improving the reliability of the system.
Furthermore, a first preset seawater inlet regulating valve opening degree of the local absorption tower and a second preset seawater flow first preset regulating coefficient are further arranged in the selection module, when the system meets a third preset condition, the selection module compares the opening degree Ka of the seawater inlet regulating valve of the local absorption tower with the opening degree of the seawater inlet regulating valve of each preset local absorption tower in sequence and selects the corresponding second preset seawater flow preset regulating coefficient according to the comparison result to regulate the second preset seawater flowThe water flow rate V2 is adjusted by selecting a stack of second preset seawater flow rate corresponding to second preset seawater flow preset adjustment coefficients according to the opening of the seawater inlet adjusting valve of the absorption tower, SO that the system can ensure that the clean flue gas outlet of the absorption tower of the machine discharges SO meeting the emission standard under the condition that the opening of the seawater inlet adjusting valve of the absorption tower of the machine is different2Thereby further improving the reliability of the system.
Further, the frequency converter of the seawater booster pump is controlled by using a cascade PID plus feedforward control strategy, the seawater desulfurization system selects a corresponding operation mode according to a feedforward signal, and if the manual selection of the local priority mode is detected, or the seawater inlet regulating valve of the on-line absorption tower is switched to the manual mode, or the MFT signal of the unit corresponding to the on-line absorption tower is switched to the local priority mode; if the manual selection of the on-line priority mode is detected, or the seawater inlet regulating valve of the absorption tower of the machine is switched to the manual mode, or the MFT signal of the unit corresponding to the absorption tower of the machine is switched to the on-line priority mode; if the manual selection coordination control mode is detected, the dual-machine coordination control mode is switched, the throttling loss of the inlet regulating valve can be effectively controlled and the increase of the power consumption of the plant can be reduced based on various operation modes, and therefore the reliability of the seawater desulfurization system is further improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic diagram showing the construction of a seawater desulfurization system according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart illustrating a seawater desulfurization control method according to an embodiment of the present invention;
FIG. 3 is a schematic diagram showing the construction of a seawater desulfurization system according to another embodiment of the present invention;
FIG. 4 shows a logic diagram for automatic control of a frequency converter of a seawater booster pump according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram illustrating a seawater desulfurization control apparatus according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
An embodiment of the present invention provides a seawater desulfurization control method, which is applied to a seawater desulfurization system, and as shown in fig. 1, the seawater desulfurization system includes a front pool 1 of a desulfurization seawater booster pump room, a first absorption tower 4, a second absorption tower 5, at least one variable-frequency control seawater booster pump 2, and a desulfurization aeration tank 6, the first absorption tower is connected to a first unit (not shown in the figure) through an original flue, the second absorption tower 5 is connected to a second unit (not shown in the figure) through an original flue, and an outlet of the seawater booster pump is respectively connected to the first absorption tower 4 and the second absorption tower 5 through a seawater inlet regulating valve of the first absorption tower 4 and a seawater inlet regulating valve of the second absorption tower 5.
The working principle of the seawater desulfurization system is as follows:
the flue gas discharged from the boiler is subjected to electric dust removal, then is boosted by a double-suction centrifugal induced-increase one induced draft fan and is sent into an absorption tower through an original flue. A part of seawater in the condenser siphon well flows into a front pool of a desulfurized seawater booster pump room by virtue of gravity, then is sent into an absorption tower by a seawater booster pump, forms good vaporific liquid drops in the absorption tower after being sprayed, and leads gas-phase SO to be condensed2Converted to liquid phase, soluble SO2Immediately reacts with seawater to form sulfite ions.
SO in the seawater in the absorption tower is removed from the flue gas2Then the acid solution is acidic, the oxygen consumption of the washing seawater passing through the absorption tower is increased, and the dissolved oxygen is reducedAnd can not be directly discharged into the sea. Therefore, the seawater for washing the flue gas is collected in the desulfurization aeration tank, mixed with the other part of seawater which is deducted from the booster pump by the siphon well of the condenser, and aerated by introducing a large amount of air into the aeration tank through two aeration fans, and finally the seawater which meets the discharge standard is discharged back to the sea.
In the prior art, the seawater inlet regulating valves of the absorption towers are manually regulated by operators, so that the reliability of a seawater desulfurization system cannot be effectively guaranteed, and in order to solve the technical problem, the seawater desulfurization control method in the embodiment automatically regulates the seawater inlet regulating valves of the absorption towers, as shown in fig. 2, the method comprises the following steps:
step S201, using one of the first absorption tower and the second absorption tower as a local absorption tower, and using the other as an on-machine absorption tower.
And S202, if a first preset condition is met, fully opening a seawater inlet regulating valve of the absorption tower of the machine.
And step S203, if a second preset condition is met, increasing the opening degree of a seawater inlet regulating valve of the absorption tower of the machine based on a first preset speed.
And step S204, if a third preset condition is met and the first preset condition or the second preset condition is not met, reducing the opening degree of a seawater inlet regulating valve of the absorption tower of the machine based on a second preset speed.
And step S205, if a fourth preset condition is met, increasing the opening degree of the seawater inlet regulating valve of the absorption tower of the machine based on the second preset rate.
In particular, the local SO of the clean flue gas outlet of the local absorption tower2A near-machine SO with the concentration of Pa and the set clean smoke outlet of the near-machine absorption tower2Setting the opening of a seawater inlet regulating valve of the absorption tower of the machine as Ka, setting the opening of a seawater inlet regulating valve of the absorption tower of the machine as Kb, and setting the inlet seawater flow of the absorption tower of the machine as Qa;
a plurality of preset SOs are set in the selected module2Concentration of first predetermined SO2Concentration P1, second predetermined SO2Concentration P2 and third predetermined SO2A concentration P3, wherein the selection module is further provided with a plurality of preset seawater flow rates, including a first preset seawater flow rate V1, a second preset seawater flow rate V2 and a third preset seawater flow rate V3;
the selected module is provided with a plurality of preset conditions, and when the system runs, the selected module can increase or decrease the opening Ka of the seawater inlet regulating valve of the absorption tower of the machine according to the preset conditions actually met by the system:
in this embodiment, each absorption tower corresponds to one generator set, the local absorption tower is the absorption tower corresponding to the current generator set, and the local absorption tower and the nearby absorption tower can be interchanged.
The states of the seawater inlet regulating valve comprise a manual state and an automatic state, and in order to reliably control the seawater inlet regulating valve, the seawater inlet regulating valve is put into the automatic state when receiving an automatic putting-in instruction sent by an operator.
In the present embodiment, the desulfurization control method is performed after the seawater inlet control valve is automatically put into operation.
Specifically, the selected module is provided with a plurality of seawater inlet regulating valves Kb, the opening degree of the seawater inlet regulating valve Kb1 of the temporary absorption tower is preset, the opening degree of the seawater inlet regulating valve Kb2 of the temporary absorption tower is preset, and the first preset SO is also arranged in the selected module2Concentration difference Δ Pa1 and second predetermined SO2The concentration difference Δ Pa 2;
when the system meets a first preset condition, a selection module calculates a local SO of a clean flue gas outlet of the local absorption tower2Concentration Pa and first predetermined SO2Setting the difference delta Pa of the concentration P1 as Pa-P1, comparing the delta Pa with delta Pa1 and delta Pa2 respectively by a selection module, determining the opening Kb of a seawater inlet regulating valve of the temporary absorption tower according to the comparison result,
when the delta Pa is less than or equal to the delta Pa1, the selected module sets the opening of a seawater inlet regulating valve of the absorber tower adjacent to the machine to be 0;
when the delta Pa1 is smaller than or equal to the delta Pa2, the selected module sets the opening degree of a seawater inlet regulating valve of the on-machine absorption tower to Kb 1;
when Δ Pa > [ Δ Pa2, the selection module sets the opening of the seawater inlet regulating valve of the mechanical absorption tower to Kb 2.
Specifically, the first preset condition is specifically that the local SO of the clean flue gas outlet of the local absorption tower is used as the local SO2The concentration is greater than the first preset concentration, and when the concentration is greater than the first preset concentration, the local SO is used2When the concentration is greater than the first preset concentration, the SO of the machine is indicated2The concentration is very high, and the SO of the machine needs to be quickly reduced in order to avoid the environmental protection parameter exceeding the standard2Concentration, thus fully opening the seawater inlet regulating valve of the local absorption tower.
Specifically, a first preset adjustment coefficient alpha 1 of the first preset seawater flow and a first preset adjustment coefficient alpha 2 of the first preset seawater flow are also arranged in the selection module;
when the system meets a second preset condition, the selection module selects a corresponding preset seawater flow rate adjustment coefficient according to the opening degree of the seawater inlet adjustment valve of the temporary absorption tower to adjust the first preset seawater flow rate V1, the adjusted first preset seawater flow rate is set to be V1',
when the opening degree of a seawater inlet regulating valve of the temporary absorption tower is 0, the selected module sets V1 to V1;
when the opening degree of a seawater inlet regulating valve of the temporary absorption tower is Kb1, the selected module sets V1 ═ V1 × α 1;
when the opening degree of the seawater inlet regulating valve of the absorption tower is Kb2, the selected module sets V1 ═ V1 × α 2.
Specifically, when the system meets a third preset condition and the system does not meet the first preset condition or the second preset condition, the module computer is selected to be in computer SO2Concentration Pb and the first predetermined SO2The difference value of the concentration P1 is delta Pb, the delta Pb is set to be Pb-P1, and the selected module is further provided with a first preset temporary SO2Concentration Pb and the first predetermined SO2The difference in concentration P1 is△Pb1；
When delta Pb is less than delta Pb1, the selected module does not adjust the opening Kb of the seawater inlet adjusting valve of the absorption tower approaching the machine;
when the delta Pb is not less than the delta Pb1, the selected module reduces the opening Kb of the seawater inlet regulating valve of the on-machine absorption tower;
in this embodiment, the inlet seawater flow rates required by different flue gas loads are different, and in a specific application scenario of the present application, when the flue gas load is not greater than 60% BMCR, the minimum flow rate is 5000m3H; when the smoke load is more than 60 percent BMCR (Boiler Maximum Continuous evaporation capacity of a Boiler), the minimum flow is 6500m3H is used as the reference value. The second preset condition is that the inlet seawater flow of the absorption tower is lower than the minimum flow corresponding to the current flue gas load. When the second preset condition is met, the flow of the seawater at the inlet of the absorption tower is insufficient, and the large seawater inlet regulating valve needs to be opened, so that the opening degree of the seawater inlet regulating valve of the absorption tower is increased based on the first preset speed.
Specifically, the selected module is also provided with a first preset local absorption tower seawater inlet regulating valve opening degree Ka1, a second preset local absorption tower seawater inlet regulating valve opening degree Ka2, a third preset local absorption tower seawater inlet regulating valve opening degree Ka3, a second preset seawater flow first preset regulating coefficient beta 1, a second preset seawater flow second preset regulating coefficient beta 2 and a second preset seawater flow third preset regulating coefficient beta 3;
when the system meets a third preset condition, the selection module compares the opening degree of the seawater inlet regulating valve of the absorption tower with the opening degree of the seawater inlet regulating valve of each preset absorption tower in sequence according to the opening degree Ka of the seawater inlet regulating valve of the absorption tower, selects a corresponding second preset seawater flow preset regulating coefficient according to the comparison result to regulate the second preset seawater flow rate V2, sets the regulated second preset seawater flow rate V2',
when Ka ≦ Ka1, the selected module sets V2 ═ V2;
when Ka1 < Ka ≦ Ka2, the selected module sets V2 ═ V2 × β 1;
when Ka2 < Ka ≦ Ka3, the selected module sets V2 ═ V2 × β 2;
when Ka > Ka3, the selected module sets V2 ═ V2 × β 3.
In this embodiment, the third preset condition is specifically that the on-machine SO at the clean flue gas outlet of the on-machine absorption tower is in the presence of the on-machine SO2The concentration is greater than the first preset concentration and is greater than the local SO2The concentration is higher than at least a second preset concentration, and when a third preset condition is met and the first preset condition or the second preset condition is not met, the online SO is indicated2The seawater inlet regulating valves of the two absorption towers are connected with the outlet of the seawater booster pump, SO that the opening degree of the seawater inlet regulating valve of the absorption tower can be reduced, the seawater is shunted to the absorption tower close to the machine, and the SO close to the machine can be reduced2And (4) concentration.
Specifically, the selected module is also provided with a first preset local absorption tower seawater inlet regulating valve opening degree Ka1, a second preset local absorption tower seawater inlet regulating valve opening degree Ka2, a third preset local absorption tower seawater inlet regulating valve opening degree Ka3, a second preset seawater flow first preset regulating coefficient beta 1, a second preset seawater flow second preset regulating coefficient beta 2 and a second preset seawater flow third preset regulating coefficient beta 3;
when the system meets a fourth preset condition, the selection module compares the opening degree of the seawater inlet regulating valve of the absorption tower with the opening degree of the seawater inlet regulating valve of each preset absorption tower in sequence according to the opening degree Ka of the seawater inlet regulating valve of the absorption tower, selects a corresponding second preset seawater flow preset regulating coefficient according to the comparison result to regulate the second preset seawater flow rate V2, sets the regulated second preset seawater flow rate V2',
when Ka ≦ Ka1, the selected module sets V2 ═ V2;
when Ka1 < Ka ≦ Ka2, the selected module sets V2 ═ V2 × β 1;
when Ka2 < Ka ≦ Ka3, the selected module sets V2 ═ V2 × β 2;
when Ka > Ka3, the selected module sets V2 ═ V2 × β 3.
In this embodiment, the fourth preset condition is specifically the local SO2Concentration ratio of organic SO2The concentration is higher than at least a third preset concentration, and when a fourth preset condition is met, the concentration indicates the SO of the machine2The concentration is high, the opening degree of a seawater inlet regulating valve of the absorption tower of the machine needs to be increased, SO that the opening degree of the seawater inlet regulating valve of the absorption tower of the machine is increased based on the second preset rate, and the SO of the machine is reduced2And (4) concentration.
In order to reduce the throttling loss of the seawater inlet regulating valve, in some embodiments of the present application, the method further comprises:
if a fifth preset condition is met and the third preset condition or the fourth preset condition is not met, increasing the opening degree of a seawater inlet regulating valve of the absorption tower of the machine based on a third preset rate;
the fifth preset condition is that the opening degree of a seawater inlet regulating valve of the absorption tower is less than 100%.
In this embodiment, when a fifth preset condition is satisfied and the third preset condition or the fourth preset condition is not satisfied, the local SO is configured to2Concentration and on-line SO2The concentration is not high, and the opening degree of the seawater inlet regulating valve of the absorption tower can be increased based on a third preset rate, so that the seawater inlet regulating valve of at least one absorption tower is fully opened, the throttling loss of the seawater inlet regulating valve is reduced, and the power consumption of a plant is reduced.
In order to further improve the reliability of the seawater desulfurization system, in some embodiments of the present application, the first preset concentration is greater than the second preset concentration, the second preset concentration is greater than the third preset concentration, the first preset rate is less than the third preset rate, and the third preset rate is less than the second preset rate.
The person skilled in the art can flexibly set the preset concentration and the preset rate according to actual needs, which does not affect the scope of the present application.
In order to further improve the reliability of the seawater desulfurization system, in some embodiments of the present application, the frequency converter of the seawater booster pump is based onControlled by a cascade PID plus feedforward control strategy that includes controlling the local SO based on a master PID controller2Concentration and the on-line SO2Concentration, controlling inlet seawater flow of the local absorption tower and the temporary absorption tower based on a secondary PID controller, wherein the feed-forward signal comprises raw flue gas SO of the local absorption tower2The product of the concentration and the total coal amount or the smoke gas amount of the corresponding unit, and the raw smoke gas SO of the on-machine absorption tower2The concentration is multiplied by the total coal or flue gas of the corresponding unit.
In this embodiment, the cascade PID plus feedforward control strategy is to connect the main PID controller and the sub PID controller in series, and then add the feedforward signal after the sub PID controller. The specific control parameters may be determined according to the debugging result, and are not described herein again. In a specific application scenario of the present application, fig. 4 shows an automatic control logic diagram of a frequency converter of a seawater booster pump in an embodiment of the present invention.
In addition, the minimum opening of the seawater inlet regulating valve in the automatic state is a preset minimum opening, and the preset minimum opening may be 60%.
To increase the flexibility of the seawater desulfurization system, in some embodiments of the present application, the input signals of the cascade PID plus feedforward control strategy include a local input signal and a temporary input signal, the local input signal includes the inlet seawater flow and the raw flue gas SO of the local absorber2Concentration, the on-line input signal comprises the inlet seawater flow and the raw flue gas SO of the on-line absorption tower2Concentration, the method further comprising:
if the manual selection of the local priority mode is detected, or the seawater inlet regulating valve of the on-line absorption tower is switched to the manual mode, or an MFT (Main Fuel Trip) signal of a unit corresponding to the on-line absorption tower is detected, switching to the local priority mode;
if the manual selection of the on-line priority mode is detected, or the seawater inlet regulating valve of the absorption tower of the machine is switched to the manual mode, or the MFT signal of the unit corresponding to the absorption tower of the machine is switched to the on-line priority mode;
if the manual selection of the coordination control mode is detected, switching to a dual-computer coordination control mode;
the local priority mode includes that the machine-approaching input signal automatically tracks the local input signal or the machine-approaching input signal is forced to be 0, the machine-approaching priority mode includes that the local input signal automatically tracks the machine-approaching input signal or the local input signal is forced to be 0, and the dual-machine coordination control mode includes that the local input signal and the machine-approaching input signal are not processed.
Considering that two sets of units and one set of unit are in an off-state, the input signal of the cascade PID and feedforward control strategy can be switched in three modes according to actual conditions, and the flexibility of the seawater desulfurization system is improved.
By applying the technical scheme, in a seawater desulfurization system comprising a first absorption tower, a second absorption tower and at least one variable-frequency control seawater booster pump, one of the first absorption tower and the second absorption tower is used as a local absorption tower, and the other one is used as an on-line absorption tower; if the first preset condition is met, fully opening a seawater inlet regulating valve of the absorption tower of the machine; if the second preset condition is met, increasing the opening of a seawater inlet regulating valve of the absorption tower of the machine based on a first preset speed; if a third preset condition is met and the first preset condition or the second preset condition is not met, reducing the opening degree of a seawater inlet regulating valve of the absorption tower of the machine based on a second preset speed; if the fourth preset condition is met, the opening degree of a seawater inlet regulating valve of the absorption tower of the machine is increased based on the second preset rate, SO that the clean flue gas outlet SO of the absorption tower is ensured2On the basis of the concentration not exceeding the standard and the minimum inlet seawater flow, the seawater inlet regulating valve is prevented from being manually regulated, so that the reliability of the seawater desulfurization system is improved, and the monitoring pressure of operators is reduced; the seawater inlet regulating valve of at least one absorption tower is fully opened, so that the throttling loss of the seawater inlet regulating valve is reduced, and the power consumption of a plant is reduced; and the frequency converter of the seawater booster pump is controlled based on a cascade PID and feedforward control strategy, so that the frequency of the seawater booster pump is reduced as much as possible, and the number of plants of the seawater booster pump is reducedConsuming electricity.
In order to further illustrate the technical idea of the present invention, the technical solution of the present invention will now be described with reference to specific application scenarios.
Fig. 3 is a schematic structural diagram of a seawater desulfurization system of a power plant, where the seawater desulfurization system includes a front pool 1 of a desulfurization seawater booster pump room, a first absorption tower 4, a second absorption tower 5, at least one variable-frequency control seawater booster pump 2, and a desulfurization aeration tank 6, the first absorption tower is connected to a first unit (not shown in the figure) through an original flue, the second absorption tower 5 is connected to a second unit (not shown in the figure) through an original flue, and an outlet of the seawater booster pump is connected to the first absorption tower 4 and the second absorption tower 5 through a seawater inlet regulating valve of the first absorption tower 4 and a seawater inlet regulating valve of the second absorption tower 5, respectively. The control strategy is as follows:
the general idea is as follows:
clean flue gas outlet SO2The seawater inlet regulating valve at the higher concentration side is kept fully open; the frequency converter of the seawater booster pump preferentially adjusts the minimum seawater flow at the inlet of the absorption tower; frequency converter of seawater booster pump simultaneously and auxiliarily adjusts SO at maximum clean flue gas outlet of two units2The concentration does not exceed the environmental protection limit.
Firstly, the seawater inlet regulating valve of the absorption tower is kept in a full-open state as much as possible.
Under special conditions, the seawater inlet regulating valve can be closed to realize the diversion of seawater to the temporary machine, SO that the SO of the temporary machine is ensured2The seawater flow at the inlet of the absorption tower is improved on the premise that the concentration does not exceed the standard. The specific control strategy is as follows:
principle:
1. at any time, guarantee the local SO2The concentration is not exceeded.
2. At any time, the minimum seawater flow of the machine is ensured.
3. The seawater inlet regulating valve of at least one unit absorption tower is always kept fully opened.
The specific strategy is as follows:
condition 1: local SO2The concentration is more than 30 mg/Nm.
Condition 2: machine absorptionThe flow of seawater at the inlet of the tower is lower than the minimum flow (the minimum flow is 5000 m)3H is used as the reference value. When the flue gas load is more than 60 percent BMCR, the minimum flow is 6500m3/h)。
Condition 3: temporary SO2Concentration higher than 30mg/Nm and SO of the machine2Concentration ratio of organic SO2The concentration is at least 10mg/Nm lower.
Condition 4: local SO2Concentration ratio of organic SO2The concentration is at least 5mg/Nm higher.
Condition 5: the opening degree of the seawater inlet regulating valve of the absorption tower is less than 100 percent.
When condition 1 is satisfied (priority is highest):
a seawater inlet regulating valve of the absorption tower of the machine is fully opened;
when condition 2 is satisfied:
the opening degree (2%/5 min) of the seawater inlet regulating valve of the absorption tower is increased.
When condition 3 is satisfied and condition 1 or condition 2 is not satisfied:
the opening degree (10%/5 min) of the seawater inlet regulating valve of the absorption tower is reduced.
When condition 4 is satisfied:
the opening degree (10%/5 min) of the seawater inlet regulating valve of the absorption tower is increased.
When condition 5 is satisfied and condition 3 or 4 is not satisfied:
the opening degree (5%/5 min) of the seawater inlet regulating valve of the absorption tower is increased.
Under other conditions:
does not participate in the regulation.
And secondly, adding automatic control logic of a frequency converter of the seawater booster pump, preferentially controlling the minimum seawater flow at the inlet of the absorption tower, and simultaneously controlling the SO at the clean flue gas outlet2And (4) concentration.
Principle:
at any time, the minimum seawater flow of the unit is ensured.
Specific strategies
As shown in fig. 4, a cascaded PID plus feedforward control strategy is employed.
1. The main PID controller controls the most of the two unitsBig clean flue gas outlet SO2And (4) concentration.
2. And the auxiliary PID controller controls the minimum seawater flow at the inlets of the two unit absorption towers.
3. The feed-forward signal being the raw flue gas SO2Concentration multiplied by total coal (flue gas) quantity.
Supplementary explanation:
1. the minimum opening degree of the seawater inlet adjusting electric door of the absorption tower is 60 percent under the automatic state.
2. The input signals of the logic (#3, #4 seawater flow; #3, #4 raw flue gas SO) take into account that there may be two units with one unit off-stream status2Concentration) is added with a control mode switching button.
Three control modes are switched: the #3 unit takes precedence, the #4 unit takes precedence and the two units coordinate and control.
The three modes act:
1) when the #3 unit is selected to have priority, the #3 unit signal is automatically tracked or forced to be 0 by the #4 unit side input signal;
2) when the #4 unit is selected to have priority, the #4 unit signal is automatically tracked or forced to be 0 by the #3 unit side input signal;
3) and the double units coordinate and control to keep the original input signals of each unit side.
Three ways trigger the condition:
1) selecting a #3 unit priority mode manually, switching a #4 unit seawater inlet regulating valve manually, and switching a #4 unit MFT signal to a #3 unit priority mode automatically by taking one trigger;
2) selecting a #4 unit priority mode manually, switching a #3 unit seawater inlet adjusting valve manually, and switching a #3 unit MFT signal to a #4 unit priority mode automatically by taking one trigger;
3) and manually selecting the dual-computer coordination control mode to trigger automatic switching to the dual-computer coordination control mode.
The control strategy is specifically verified by taking the situation that a second-stage unit and a first-stage unit of a certain power plant are under the same boiler load and the same coal type. Experiments prove that the secondary unit adopting the control strategy saves the electricity consumption by about 20 percent compared with the primary unit desulfurizing seawater booster pump without adopting the control strategy, and obviously reduces the plant power consumption rate.
Corresponding to the seawater desulfurization control method in the embodiment of the present application, an embodiment of the present invention further provides a seawater desulfurization control apparatus, which is applied to a seawater desulfurization system, where the seawater desulfurization system includes a first absorption tower, a second absorption tower, and at least one variable-frequency-control seawater booster pump, the first absorption tower is connected to a first unit through an original flue, the second absorption tower is connected to a second unit through an original flue, an outlet of the seawater booster pump is connected to the first absorption tower and the second absorption tower through a seawater inlet regulating valve of the first absorption tower and a seawater inlet regulating valve of the second absorption tower, respectively, as shown in fig. 5, the apparatus includes:
a selecting module 501, configured to use one of the first absorption tower and the second absorption tower as a local absorption tower, and use the other as an on-machine absorption tower;
the first adjusting module 502 is used for fully opening the seawater inlet adjusting valve of the absorption tower of the machine if a first preset condition is met;
a second adjusting module 503, configured to increase an opening of a seawater inlet adjusting valve of the local absorption tower based on a first preset rate if a second preset condition is met;
a third adjusting module 504, configured to reduce an opening of a seawater inlet adjusting valve of the local absorption tower based on a second preset rate if a third preset condition is met and the first preset condition or the second preset condition is not met;
a fourth adjusting module 505, configured to increase an opening degree of a seawater inlet adjusting valve of the local absorption tower based on the second preset rate if a fourth preset condition is met;
wherein the first preset condition is specifically the local SO of the clean flue gas outlet of the local absorption tower2The concentration is greater than a first preset concentration, the second preset condition is that the flow of seawater at the inlet of the local absorption tower is lower than the minimum flow corresponding to the current flue gas load, and the third preset condition is that the on-line SO at the clean flue gas outlet of the on-line absorption tower is close to the on-line SO2The concentration is greater than the first preset concentration and is greater than the local SO2The concentration is higher than at least a second preset concentration, and the fourth preset condition is specifically that the machine SO2Concentration ratio of the said in-situ SO2The concentration is higher than at least a third preset concentration
In a specific application scenario of the present application, the apparatus further includes:
the fifth adjusting module is used for increasing the opening of a seawater inlet adjusting valve of the absorption tower of the machine based on a third preset speed if a fifth preset condition is met and the third preset condition or the fourth preset condition is not met;
the fifth preset condition is that the opening degree of a seawater inlet regulating valve of the absorption tower is less than 100%.
In a specific application scenario of the application, the first preset concentration is greater than the second preset concentration, the second preset concentration is greater than the third preset concentration, the first preset rate is less than the third preset rate, and the third preset rate is less than the second preset rate.
In a specific application scenario of the present application, the frequency converter of the seawater booster pump is controlled based on a cascade PID plus feedforward control strategy, where the cascade PID plus feedforward control strategy includes controlling the local SO based on a main PID controller2Concentration and the on-line SO2Concentration, controlling inlet seawater flow of the local absorption tower and the temporary absorption tower based on a secondary PID controller, wherein the feed-forward signal comprises raw flue gas SO of the local absorption tower2The product of the concentration and the total coal amount or the smoke gas amount of the corresponding unit, and the raw smoke gas SO of the on-machine absorption tower2The concentration is multiplied by the total coal or flue gas of the corresponding unit.
In a specific application scenario of the present application, the input signals of the cascade PID plus feedforward control strategy include a local input signal and a temporary input signal, where the local input signal includes an inlet seawater flow and a raw flue gas SO of the local absorption tower2Concentration, the on-line input signal comprises the inlet seawater flow and the raw flue gas SO of the on-line absorption tower2Concentration of, said isThe device further comprises a switching module for:
if the manual selection of the local priority mode is detected, or the seawater inlet regulating valve of the on-machine absorption tower is switched to the manual mode, or the MFT signal of the unit corresponding to the on-machine absorption tower is switched to the local priority mode;
if the manual selection of the on-line priority mode is detected, or the seawater inlet regulating valve of the absorption tower of the machine is switched to the manual mode, or the MFT signal of the unit corresponding to the absorption tower of the machine is switched to the on-line priority mode;
if the manual selection of the coordination control mode is detected, switching to a dual-computer coordination control mode;
the local priority mode includes that the machine-approaching input signal automatically tracks the local input signal or the machine-approaching input signal is forced to be 0, the machine-approaching priority mode includes that the local input signal automatically tracks the machine-approaching input signal or the local input signal is forced to be 0, and the dual-machine coordination control mode includes that the local input signal and the machine-approaching input signal are not processed.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not necessarily depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims (9)

1. A seawater desulfurization control method is applied to a seawater desulfurization system and is characterized by comprising the following steps:
the selection module takes one of the first absorption tower and the second absorption tower as a local absorption tower and takes the other one as an on-line absorption tower;
wherein the local SO of the clean flue gas outlet of the local absorption tower is set2Setting the net flue gas outlet of the on-machine absorption tower at the concentration of PaMechanical SO2Setting the opening of a seawater inlet regulating valve of the absorption tower of the machine as Ka, setting the opening of a seawater inlet regulating valve of the absorption tower of the machine as Kb, and setting the inlet seawater flow of the absorption tower of the machine as Qa;
a plurality of preset SOs are set in the selected module2Concentration of first predetermined SO2Concentration P1, second predetermined SO2Concentration P2 and third predetermined SO2A concentration P3, wherein the selection module is further provided with a plurality of preset seawater flow rates, including a first preset seawater flow rate V1, a second preset seawater flow rate V2 and a third preset seawater flow rate V3;
the selected module is provided with a plurality of preset conditions, and when the system runs, the selected module can increase or decrease the opening Ka of the seawater inlet regulating valve of the absorption tower of the machine according to the preset conditions actually met by the system:
if the system meets a first preset condition, fully opening a seawater inlet regulating valve of the absorption tower of the machine;
if the system meets a second preset condition, increasing the opening Ka of a seawater inlet regulating valve of the absorption tower of the machine based on a first preset seawater flow rate V1;
if the system meets a third preset condition and does not meet the first preset condition or the second preset condition, reducing the opening Ka of a seawater inlet regulating valve of the absorption tower of the machine based on a second preset seawater flow rate V2;
if the system meets a fourth preset condition, increasing the opening Ka of a seawater inlet regulating valve of the absorption tower of the machine based on the second preset seawater flow rate V2;
if the system meets a fifth preset condition and does not meet the third preset condition or the fourth preset condition, increasing the opening Ka of a seawater inlet regulating valve of the absorption tower of the system based on a third preset speed V3;
wherein the first preset condition is that the machine SO of the clean flue gas outlet of the machine absorption tower2The concentration Pa is greater than the first preset SO2Concentration P1, the second preset condition is that the inlet of the absorption tower isThe flow Qa of the seawater is lower than the minimum flow Qmin corresponding to the current flue gas load, and the third preset condition is that the clean flue gas outlet of the on-machine absorption tower is in an on-machine SO state2The concentration Pb is greater than the first preset SO2Concentration P1 and ratio of the local SO2The concentration Pa is higher than at least a second preset concentration P2, and the fourth preset condition is that the machine SO is used2Concentration Pa is higher than that of the temporary SO2The concentration Pb is higher than at least a third preset concentration P3, and the fifth preset condition is that the opening degree of a seawater inlet regulating valve of the absorption tower is smaller than 100%.
2. The seawater desulfurization control method according to claim 1, wherein the selected module has a plurality of seawater inlet control valves Kb, and the selected module further has a first preset seawater inlet control valve Kb1, a second preset seawater inlet control valve Kb2, and a first preset SO 22Concentration difference Δ Pa1 and second predetermined SO2The concentration difference Δ Pa 2;
when the system meets a first preset condition, a selection module calculates a local SO of a clean flue gas outlet of the local absorption tower2Concentration Pa and first predetermined SO2Setting the difference delta Pa of the concentration P1 as Pa-P1, comparing the delta Pa with delta Pa1 and delta Pa2 respectively by a selection module, determining the opening Kb of a seawater inlet regulating valve of the temporary absorption tower according to the comparison result,
when the delta Pa is less than or equal to the delta Pa1, the selected module sets the opening of a seawater inlet regulating valve of the absorber tower adjacent to the machine to be 0;
when the delta Pa1 is smaller than or equal to the delta Pa2, the selected module sets the opening degree of a seawater inlet regulating valve of the on-machine absorption tower to Kb 1;
when Δ Pa > [ Δ Pa2, the selection module sets the opening of the seawater inlet regulating valve of the mechanical absorption tower to Kb 2.
3. The seawater desulfurization control method according to claim 1, wherein the selected module further comprises a first preset seawater flow first preset adjustment coefficient α 1 and a first preset seawater flow first preset adjustment coefficient α 2;
when the system meets a second preset condition, the selection module selects a corresponding preset seawater flow rate adjustment coefficient according to the opening degree of the seawater inlet adjustment valve of the temporary absorption tower to adjust the first preset seawater flow rate V1, the adjusted first preset seawater flow rate is set to be V1',
when the opening degree of a seawater inlet regulating valve of the temporary absorption tower is 0, the selected module sets V1 to V1;
when the opening degree of a seawater inlet regulating valve of the temporary absorption tower is Kb1, the selected module sets V1 ═ V1 × α 1;
when the opening degree of the seawater inlet regulating valve of the absorption tower is Kb2, the selected module sets V1 ═ V1 × α 2.
4. The seawater desulfurization control method of claim 1, wherein the selection module is configured to calculate the computer-aided SO when the system satisfies a third predetermined condition and the system does not satisfy the first predetermined condition or the second predetermined condition2Concentration Pb and the first predetermined SO2The difference value of the concentration P1 is delta Pb, the delta Pb is set to be Pb-P1, and the selected module is further provided with a first preset temporary SO2Concentration Pb and the first predetermined SO2The difference in concentration P1 is Δ Pb 1;
when delta Pb is less than delta Pb1, the selected module does not adjust the opening Kb of the seawater inlet adjusting valve of the absorption tower approaching the machine;
when the delta Pb is not less than the delta Pb1, the selected module reduces the opening Kb of the seawater inlet regulating valve of the on-machine absorption tower.
5. The seawater desulfurization control method according to claim 1, wherein the selected module further comprises a first preset local absorption tower seawater inlet regulating valve opening Ka1, a second preset local absorption tower seawater inlet regulating valve opening Ka2, a third preset local absorption tower seawater inlet regulating valve opening Ka3, a second preset seawater flow rate first preset regulating coefficient β 1, a second preset seawater flow rate second preset regulating coefficient β 2, and a second preset seawater flow rate third preset regulating coefficient β 3;
when the system meets a fourth preset condition, the selection module compares the opening degree of the seawater inlet regulating valve of the absorption tower with the opening degree of the seawater inlet regulating valve of each preset absorption tower in sequence according to the opening degree Ka of the seawater inlet regulating valve of the absorption tower, selects a corresponding second preset seawater flow preset regulating coefficient according to the comparison result to regulate the second preset seawater flow rate V2, sets the regulated second preset seawater flow rate V2',
when Ka ≦ Ka1, the selected module sets V2 ═ V2;
when Ka1 < Ka ≦ Ka2, the selected module sets V2 ═ V2 × β 1;
when Ka2 < Ka ≦ Ka3, the selected module sets V2 ═ V2 × β 2;
when Ka > Ka3, the selected module sets V2 ═ V2 × β 3.
6. The seawater desulfurization control method of claim 2, wherein the first preset SO is2The concentration P1 is greater than the second preset SO2Concentration P2, the second predetermined SO2The concentration P2 is greater than the third preset SO2Concentration P3, the first preset seawater flow rate V1 being less than the third preset seawater flow rate V3, the third preset seawater flow rate V3 being less than the second preset seawater flow rate V2.
7. The method of claim 1, wherein the frequency converter of the seawater booster pump is controlled based on a cascade PID plus feedforward control strategy comprising controlling the local SO based on a primary PID controller2Concentration and the on-line SO2Concentration, controlling inlet seawater flow of the local absorption tower and the temporary absorption tower based on a secondary PID controller, wherein the feed-forward signal comprises raw flue gas SO of the local absorption tower2The product of the concentration and the total coal or flue gas volume of the corresponding unit, andcrude flue gas SO of absorption tower near machine2The concentration is multiplied by the total coal or flue gas of the corresponding unit.
8. The seawater desulfurization control method of claim 7, wherein the input signals of the cascade PID plus feedforward control strategy comprise a local input signal and a temporary input signal, the local input signal comprises an inlet seawater flow rate of the local absorption tower and raw flue gas SO2Concentration, the on-line input signal comprises the inlet seawater flow and the raw flue gas SO of the on-line absorption tower2Concentration, the method further comprising:
if the manual selection of the local priority mode is detected, or the seawater inlet regulating valve of the on-machine absorption tower is switched to the manual mode, or the MFT signal of the unit corresponding to the on-machine absorption tower is switched to the local priority mode;
if the manual selection of the on-line priority mode is detected, or the seawater inlet regulating valve of the absorption tower of the machine is switched to the manual mode, or the MFT signal of the unit corresponding to the absorption tower of the machine is switched to the on-line priority mode;
if the manual selection of the coordination control mode is detected, switching to a dual-computer coordination control mode;
the local priority mode includes that the machine-approaching input signal automatically tracks the local input signal or the machine-approaching input signal is forced to be 0, the machine-approaching priority mode includes that the local input signal automatically tracks the machine-approaching input signal or the local input signal is forced to be 0, and the dual-machine coordination control mode includes that the local input signal and the machine-approaching input signal are not processed.
9. A seawater desulfurization control apparatus using the seawater desulfurization control method according to any one of claims 1 to 8, wherein the seawater desulfurization system comprises a first absorption tower connected to a first unit through a raw flue, a second absorption tower connected to a second unit through a raw flue, and at least one variable-frequency-controlled seawater booster pump, an outlet of the seawater booster pump is connected to the first absorption tower and the second absorption tower through a seawater inlet regulating valve of the first absorption tower and a seawater inlet regulating valve of the second absorption tower, respectively, the apparatus comprising:
a selection module, configured to use one of the first absorption tower and the second absorption tower as a local absorption tower, and use the other as an on-machine absorption tower;
the first adjusting module is used for fully opening a seawater inlet adjusting valve of the absorption tower of the machine if a first preset condition is met;
the second adjusting module is used for increasing the opening of the seawater inlet adjusting valve of the absorption tower of the machine based on a first preset speed if a second preset condition is met;
the third adjusting module is used for reducing the opening of a seawater inlet adjusting valve of the absorption tower of the machine based on a second preset speed if a third preset condition is met and the first preset condition or the second preset condition is not met;
the fourth adjusting module is used for increasing the opening of the seawater inlet adjusting valve of the absorption tower of the machine based on the second preset speed if a fourth preset condition is met;
wherein the first preset condition is specifically the local SO of the clean flue gas outlet of the local absorption tower2The concentration is greater than a first preset concentration, the second preset condition is that the flow of seawater at the inlet of the local absorption tower is lower than the minimum flow corresponding to the current flue gas load, and the third preset condition is that the on-line SO at the clean flue gas outlet of the on-line absorption tower is close to the on-line SO2The concentration is greater than the first preset concentration and is greater than the local SO2The concentration is higher than at least a second preset concentration, and the fourth preset condition is specifically that the machine SO2Concentration ratio of the said in-situ SO2The concentration is higher by at least a third preset concentration.
CN202110560604.1A 2021-05-21 2021-05-21 Seawater desulfurization control method and equipment Active CN113198294B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202110560604.1A CN113198294B (en) 2021-05-21 2021-05-21 Seawater desulfurization control method and equipment
JP2022066631A JP2022179349A (en) 2021-05-21 2022-04-13 Seawater desulfurization control method and device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110560604.1A CN113198294B (en) 2021-05-21 2021-05-21 Seawater desulfurization control method and equipment

Publications (2)

Publication Number Publication Date
CN113198294A CN113198294A (en) 2021-08-03
CN113198294B true CN113198294B (en) 2021-11-19

Family

ID=77023032

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110560604.1A Active CN113198294B (en) 2021-05-21 2021-05-21 Seawater desulfurization control method and equipment

Country Status (2)

Country Link
JP (1) JP2022179349A (en)
CN (1) CN113198294B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113864005B (en) * 2021-08-16 2024-06-11 华能国际电力股份有限公司大连电厂 Operation method of water supply pump steam turbine
CN116173699A (en) * 2023-03-02 2023-05-30 北京亿玮坤节能科技有限公司 Small nozzle energy-saving high-efficiency desulfurization system

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62130722U (en) * 1986-02-10 1987-08-18
JP5773687B2 (en) * 2011-02-28 2015-09-02 三菱日立パワーシステムズ株式会社 Seawater flue gas desulfurization system and power generation system
CN104736225B (en) * 2013-01-29 2018-05-04 富士电机株式会社 The seawater amount control device of Drechsel system, the seawater amount control method of Drechsel system, alkali number control device and alkali number control method
CN104703675A (en) * 2013-04-17 2015-06-10 富士电机株式会社 Exhaust gas treatment device, vessel, and exhaust gas treatment method
DK2976147T3 (en) * 2013-05-08 2018-04-30 Langh Patents Oy Ab PROCEDURE FOR TREATING CURRENTS INCLUDED IN SHIP'S EXHAUST GASES AND SHIPS WITH A SCRUB CLEANING UNIT
US9771279B2 (en) * 2015-03-31 2017-09-26 General Electric Technology Gmbh Foam intercept system
JP6737315B2 (en) * 2018-10-18 2020-08-05 栗田工業株式会社 Inventory management system and inventory management method for treating agents used for treating exhaust gas

Also Published As

Publication number Publication date
JP2022179349A (en) 2022-12-02
CN113198294A (en) 2021-08-03

Similar Documents

Publication Publication Date Title
CN113198294B (en) Seawater desulfurization control method and equipment
CN109101049B (en) Desulfurization absorption tower pH value-to-power frequency hybrid control system and method
CN106362575B (en) A kind of heat-engine plant desulfurized spray system and method for controlling desulfurization
CN107224862A (en) It is a kind of to carry out low concentration SO using fuzzy alkali adding method2The device and method of flue gas desulfurization
CN107648988A (en) A kind of device and method of double loop regulation desulfurization for slurry flow
CN210699477U (en) Device for adjusting desulfurization slurry supply flow rate by adding feedforward to single PID loop
CN114281042A (en) Energy-saving control method and device for wet desulphurization circulating system
CN112999857B (en) Regulation and control method and regulation and control system for wide-load limestone slurry supply system
CN206253001U (en) It is a kind of to possess the Deuslfurizing system for sea water that complementary energy reclaims function
JP2010276203A (en) Control device of power plant condensate system
CN113405088A (en) Three-impulse frequency conversion automatic adjusting method
CN209596870U (en) A kind of desulphurization system of underload energy-saving safe
CN208472854U (en) A kind of constant pressure water supply system of fixed frequency pump
CN106563336B (en) A kind of ship washing desulphurization devices and methods therefor that high underload is applicable
CN113685800B (en) Automatic parallel pump control system of steam-driven water supply pump based on rate self-adaption
CN205361053U (en) Wet flue gas desulfurization supplies thick liquid device
CN108744943A (en) A kind of desulphurization plant and its sulfur removal technology
CN215997728U (en) Water pressure self-adaptation washing unit
CN211487158U (en) High-efficiency grading composite desulfurizing tower with control system
CN108310952A (en) A kind of desulfurization and denitrification integral system and its build bed process
WO2021128497A2 (en) Method, system and apparatus for controlling emission index in ship exhaust desulphurization
CN115253652B (en) Desulfurization single-tower double-circulation automatic slurry supply control method and device
CN212327889U (en) Fault emergency processing system of limestone slurry supply system
CN109758873B (en) Low-load safe energy-saving desulfurization method and system
CN218393043U (en) Frequency conversion slurry circulating pump system suitable for double-tower double-circulation desulfurization device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant