CN106731465B - Alkali sulphur absorbs low-temperature corrosion preventing control method when a kind of coal-fired flue-gas depth is cooling - Google Patents
Alkali sulphur absorbs low-temperature corrosion preventing control method when a kind of coal-fired flue-gas depth is cooling Download PDFInfo
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- 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
- B01D53/02—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 adsorption, e.g. preparative gas chromatography
- B01D53/04—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 adsorption, e.g. preparative gas chromatography with stationary adsorbents
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- 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
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- 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
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
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Abstract
Alkali sulphur absorbs low-temperature corrosion preventing control method when cooling the invention discloses a kind of coal-fired flue-gas depth, and this method is according to formulaCalculate alkali sulphur ratio CA/SWith the value of the uneven accumulation factor M in flow field；Alkali sulphur is than disclosing the mechanism of alkali sulphur absorption, control alkali sulphur is than only realizing that ash absorbs SO in flue gas from the conceptive of matter3Or H2SO4Necessary condition；The accumulation of the uneven accumulation factor characterization efficiency loss in flow field, reflects that ash absorbs SO3/H2SO4(g)/H2SO4(l) adequate condition；It controls alkali sulphur ratio and is greater than critical value 0.5, and make uneven accumulation factor control in 15~30 ranges, ash particle can be realized to SO3/H2SO4(g)/H2SO4(l) efficient absorption significantly reduces the low-temperature corrosion rate of flue gas deep cooler, and the grey cooperation-removal of acid is realized in subsequent electrostatic precipitator；The present invention breaches the grey sulphur of external proposition than single discriminant criterion, has been put forward for the first time through control alkali sulphur than realizing that flue gas deep cooler corrodes the double criterion evaluation methods and index of prevention and control with the uneven accumulation factor in flow field.
Description
Technical field
The invention belongs to the technical fields that gas-liquid solid caustic soda sulphur in ash-laden gas deep cooler absorbs, and in particular to a kind of combustion
Alkali sulphur absorbs low-temperature corrosion preventing control method when flue-gas depth is cooling.
Background technique
Coal-burning power plant consumes the 50% of coal in China total amount every year, is the main force of China's energy-saving and emission-reduction." implement in full fire coal
Power plant's minimum discharge and reducing energy consumption programme of work " it points out, arrive the year two thousand twenty, all coal-burning power plant's power for having transformation condition in the whole nation
Strive realize minimum discharge (i.e. under the conditions of benchmark oxygen content 6%, flue dust, SO2, discharged nitrous oxides concentration be respectively no higher than 10,
35,50 milligram/cubic metre), the conditional newly-built Thermal generation unit in the whole nation reaches minimum discharge level.Flue gas depth cools down skill
Art is to realize the key technology of coal-burning power plant's energy-saving and emission-reduction and minimum discharge, and core is will to enter the flue gas temperature of electrostatic precipitator
Degree is reduced to sulphuric acid dew point temperature, depth Mist heat recovering, while promoting ash particle and SO3Or H2SO4Gas-liquid solid caustic soda sulphur occurs
It absorbs, to realize that flue gas deep cooler low-temperature corrosion is controllable.
When flue gas depth be cooled to sulphuric acid dew point and it is following when, if ash particle and SO in flue gas3Or H2SO4It can be realized
Efficient gas-liquid solid caustic soda sulphur absorbs, and it is controllable that low-temperature corrosion can be realized.It is generally acknowledged that SO3Process in conjunction with vapor is higher
At a temperature of just have begun progress, flue gas temperature decrease after air preheater, almost all SO3Cooling is converted to gaseous
H2SO4.When flue gas continues to drop near flue gas acid dew point by depth is cooling, gaseous H2SO4Start condensation and forms liquid sulfur
Acid.SO3Or H2SO4It is generally acknowledged that there are two types of modes with the cohesive process of ash particle, one is physical absorption, and one is ashes
The neutralization of particle neutral and alkali ingredient.Physical suction-operated by ash particle surface area, pore structure, pore size etc. it is many-sided because
The influence of element, to SO3/H2SO4(g)/H2SO4(l) it is alkaline components in ash particle that absorption, which plays a decisive role, predominantly alkali
Metal oxide (such as Na2O、K2O etc.) and alkaline earth oxide (such as CaO, MgO), these alkaline components are in higher temperature
Under start to SO3/H2SO4(g)/H2SO4(l) there is absorption, when flue-gas temperature is reduced near acid dew point and is following, with
H2SO4Acid-base neutralization reaction occurs.Ash particle absorbs SO3Or H2SO4Later, specific resistance reduces, and surface viscosity increases, and little particle is poly-
Collect coalescence into bulky grain, removing is realized in subsequent electrostatic precipitator.
Then, Japanese associated companies are proposed by controlling one-parameter discriminant criterion of the grey sulphur than inhibiting low-temperature corrosion risk,
Grey sulphur is than being gas and dust characters (mg/m3) and SO3Mass concentration (mg/m3)The ratio between.However to grey in flue gas depth cooling procedure
Particle and SO3Or H2SO4Gas-liquid solid caustic soda sulphur absorption mechanism is the study found that SO in ash particle3/H2SO4(g)/H2SO4(l) absorption
What is played a major role is alkaline components, mainly by alkali metal oxide (such as Na2O、K2O etc.) and alkaline earth oxide is (such as
CaO, MgO etc.) composition, and with when flue-gas temperature is reduced near acid dew point and is following and H2SO4Acid-base neutralization reaction occurs.
Grey sulphur than be a kind of macroscopic view evaluation index, only only account for ash particle concentration in flue gas, and have ignored in ash particle to SO3
Or H2SO4The alkaline components for having absorbed practical function, do not ensure that low-temperature corrosion is in controllable state.It is cold in flue gas depth
But, it was also found that the coal quality situation in China and Japan differ widely in the engineering practice of device design and operation, content of ashes is higher, sulphur
Content is lower, and grey sulphur is most of all 500 or more than usually up to 1000 or more.The flue gas depth of even some typical power plant
When cooler is run, even if less than 5 low-temperature corrosion does not also occur for the grey sulphur ratio calculated, it may be said that Japanese associated companies propose
" grey sulphur ratio be greater than 100 " saying substantial deviation practical implementation.Therefore, grey sulphur ratio cannot accurately and reliably reflect flue gas
Alkali sulfur absorption rate in depth cooling procedure is also simply unreasonable using its index controllable as low-temperature corrosion.
In the flue gas deep cooler system SO to actual motion3Or H2SO4It is found after concentration determination, existing flue gas is deep
Degree cooling technology can not achieve ash particle and SO3Or H2SO4High-efficient alkali sulphur absorb.On the one hand, due to flue gas deep cooler
Often there is the special-shaped through-flow and Pipe bundle structure such as flue gas turning, sudden expansion, tapered, three-dimensional elbow in system, these abnormity are through-flow and pipe
The presence of binding structure causes smoke-filling movement, velocity field and ash particle concentration field uneven distribution, reduces having for alkali sulphur absorption
Effect property；On the other hand, since flue shuts off the different particle size distribution of ash particle in face, ash particle efficient absorption in flue gas is influenced
SO3Or H2SO4.Even flow field degree is to ash particle and SO3Or H2SO4High-efficient alkali sulphur absorption play considerable effect,
However efficiency loss is evaluated still without a comprehensive index of system at present to gas-liquid-solid in flue gas depth cooling procedure
The influence of alkali sulfur absorption rate, to realize that flue gas deep cooler corrodes prevention and control.
Summary of the invention
In order to overcome the above-mentioned problems of the prior art, the purpose of the present invention is to provide a kind of coal-fired flue-gas depth is cold
Alkali sulphur absorbs low-temperature corrosion preventing control method when but, realizes efficient gas by the uneven accumulation factor of control alkali sulphur ratio and flow field
Liquid solid caustic soda sulphur absorbs, and the low-temperature corrosion of effectively prevention and control flue gas deep cooler.
In order to achieve the above object, the invention adopts the following technical scheme:
Alkali sulphur absorbs low-temperature corrosion preventing control method when a kind of coal-fired flue-gas depth is cooling, method includes the following steps:
Step 1 carries out grey neutral and alkali metal oxide according to national standard GB/T1574-2007 " coal ash analysis method "
Fe2O3、CaO、MgO、Na2O and K2The test of O mass content；
Step 2 carries out converting the sum of the mass percent of alkaline metal oxide Wt in ashACalculating:
In formula:--- Fe in ash2O3Mass content, %；
WtCaO--- CaO mass content in ash, %；
WtMgO--- MgO mass content in ash, %；
--- Na in ash2O mass content, %；
--- K in ash2O mass content, %；
Step 3 carries out converting alkaline metal oxide content C in ashACalculating:
CA=CD×WtA
In formula: CD--- gas cooler entrance dust concentration, mg/m3；
WtA--- the sum of the mass percent of alkaline metal oxide, % are converted in ash；
Step 4 carries out gas cooler entrance SO3ConcentrationCalculating:
In formula: η1--- As-received sulphur is converted into SO in fire coal2Conversion ratio；
η2——SO2To SO3Conversion ratio；
M --- boiler fired coal amount, t/h；
Sar--- As-received sulfur content in fire coal, %；
q4--- the heat loss of imperfect solid combustion of boiler, %；
Q --- flue gas flow, m3/h；
Step 5 carries out alkali sulphur ratio CA/SCalculating:
In formula:--- gas cooler entrance SO3Concentration, mg/m3；
CA--- alkaline metal oxide content, mg/m are converted in ash3；
Step 6 carries out flue and heat-exchanging tube bundle that coal-burning power plant's air preheater outlet is exported to flue gas deep cooler
Local coefficient m calculating:
In formula: k --- gas-solid impact factor, dimensionless；
A --- flue gas passes through the average angle turned over when different polymorphic structures, °；
S1--- flue gas passes through the flow area before different polymorphic structures, m2；
S2--- flow area of the flue gas after different polymorphic structures, m2；
Step 7, the calculating for carrying out the uneven accumulation factor M in flow field:
In formula: mi--- flue gas passes through local coefficient when different polymorphic structures；
The uneven accumulation factor M in flow field is a kind of criterion for evaluating efficiency loss, carrys out evaluation of flue gas with this and exists
When by special-shaped through-flow and Pipe bundle structure, the accumulation of efficiency loss；
Step 8, alkali sulphur absorb low-temperature corrosion preventing control method:
Control alkali sulphur ratio CA/SOnly realize grey efficient absorption SO in flue gas3Or H2SO4Necessary condition, alkali sulphur ratio is bigger,
Alkali sulfur absorption rate is higher；And controlling the uneven accumulation factor M in flow field is to determine grey efficient absorption SO3Or H2SO4Adequate condition,
Within the specified scope, the uneven accumulation factor in flow field is smaller, and alkali sulfur absorption rate is higher；
As long as designing and running time control alkaline sulphur ratio C in flue gas deep coolerA/SGreater than critical value 0.5, and make uneven
When accumulation factor M control is in 15~30 ranges, grey efficient absorption SO in flue gas can be realized3Or H2SO4, significantly reduce flue gas
The low-temperature corrosion rate of deep cooler, on the one hand, realize the safe and highly efficient operation of flue gas deep cooler, on the other hand, ash
Absorb SO3Or H2SO4Afterwards, cooperation-removal ash and SO will be realized in subsequent electrostatic precipitator3Or H2SO4Purpose；
As the alkali sulphur ratio CA/SWhen being not greater than critical value, the coal different to alkaline metal oxide content is mixed
Match, or uniformly spray alkaline metal oxide powder directly into flue gas, improves the alkalinous metal oxygen that coal-burning power plant uses coal
Compound content realizes that high-efficient alkali sulphur absorbs to improve the alkali sulphur ratio for using coal, and effective prevention and control flue gas deep cooler
Low-temperature corrosion；
When the stream of flue and heat-exchanging tube bundle that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports
When the uneven accumulation factor M in field is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and even flow field is set
Meter reduces flue gas and passes through the average angle turned over when different polymorphic structures, and keeps smoke-filling movement, velocity field and ash particle dense
Degree field energy enough has the function of that collaboration improves alkali sulfur absorption rate.
Preferably, for coal-powder boiler, As-received sulphur is converted into SO in the fire coal2Conversion ratio η1Take 90%；It is described
SO2To SO3Conversion ratio η2Take 1.8%-2.2%.
Preferably, the alkaline metal oxide powder directly uniformly sprayed into flue gas is CaO or MgO powder.
Preferably, as the alkali sulphur ratio CA/SIt is different to alkaline metal oxide content when being not greater than critical value 0.5
Coal carries out mixture, refers to the low coal of the high coal of alkalinous metal content and alkalinous metal content carrying out ratio coal blending, will fire
0.5 or more is increased to the alkali sulphur ratio of coal.
Preferably, when the flue and heat exchanger tube that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports
When the uneven accumulation factor M in the flow field of beam is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and flow field is equal
Design is homogenized, refers to sectional dimension, the shape, angle of turn for changing flue, increases deflector, so that even flow field.
Preferably, when the flue and heat exchanger tube that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports
When the uneven accumulation factor M in the flow field of beam is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and flow field is equal
Design is homogenized, refers to structure, shape and the sectional dimension for changing heat exchanger, redesigns enhanced heat transfer component, or change and strengthen
The structure of heat transfer element, so that even flow field.
Compared to the prior art compared with, the beneficial effects of the present invention are:
(1) the method for the present invention alkali sulphur ratio is reality and SO in ash particle3Or H2SO4The conversion alkali of absorption coalescence effect occurs
Property oxide content and gas cooler entrance SO3The ratio between concentration, by control alkali sulphur than realizing efficient gas-liquid solid caustic soda sulphur
It absorbs.Compared with grey sulphur ratio, alkali sulphur, which compares in ash particle, absorbs SO3Or H2SO4Ingredient carried out more careful division, should
Index can intuitively reflect ash particle and SO3/H2SO4(g)/H2SO4(l) alkali sulfur absorption rate.
(2) the method for the present invention is using alkali sulphur than characterization ash particle and SO3/H2SO4(g)/H2SO4(l) gas-liquid solid caustic soda sulphur is inhaled
Yield discloses the mechanism of alkali sulphur absorption from the conceptive of matter, provides for gas-liquid solid caustic soda sulphur absorption in flue gas depth cooling procedure
One more accurate and reliable evaluation method and index.
(3) the uneven accumulation factor in the method for the present invention flow field reflects flue gas stream when by special-shaped through-flow and Pipe bundle structure
The accumulation of field inhomogeneities passes through the uneven accumulation factor in control flow field and realizes that efficient gas-liquid solid caustic soda sulphur absorbs.It is different
Shape is through-flow and the presence of Pipe bundle structure makes smoke-filling movement, velocity field and dust concentration field distribution uneven, therefore, flue gas temperature
The inhomogeneities of degree field, velocity field and particle concentration field is liquid solid caustic soda sulphur absorption process when actual influence flue gas depth is cooling
The control of key, the uneven accumulation factor in flow field provides another important evaluation method and index for the absorption of gas-liquid solid caustic soda sulphur.
(4) the grey sulphur that the method for the present invention breaches external proposition has been put forward for the first time than single discriminant criterion through control alkali
Sulphur than with the uneven accumulation factor in flow field double criterion evaluation methods and index that realize low-temperature corrosion controllable.As long as in flue gas depth
Cooler design and operation time control alkaline sulphur ratio are greater than critical value, and make uneven accumulation factor control in a certain range, i.e.,
Grey efficient absorption SO in flue gas can be achieved3Or H2SO4, the low-temperature corrosion rate of flue gas deep cooler is significantly reduced, realizes flue gas
Deep cooler corrodes prevention and control.
Specific embodiment
The present invention is described in detail below.
Alkali sulphur absorbs low-temperature corrosion preventing control method when a kind of coal-fired flue-gas depth is cooling, method includes the following steps:
Step 1 carries out grey neutral and alkali metal oxide according to national standard GB/T1574-2007 " coal ash analysis method "
Fe2O3、CaO、MgO、Na2O、K2The test of O mass content；
Step 2 carries out converting the sum of the mass percent of alkaline metal oxide Wt in ashACalculating:
In formula:--- Fe in ash2O3Mass content, %；
WtCaO--- CaO mass content in ash, %；
WtMgO--- MgO mass content in ash, %；
--- Na in ash2O mass content, %；
--- K in ash2O mass content, %；
Step 3 carries out converting alkaline metal oxide content C in ashACalculating:
CA=CD×WtA
In formula: CD--- gas cooler entrance dust concentration, mg/m3；
WtA--- the sum of the mass percent of alkaline metal oxide, % are converted in ash；Step 4 carries out gas cooler
Entrance SO3ConcentrationCalculating:
In formula: η1--- As-received sulphur is converted into SO in fire coal2Conversion ratio；
η2——SO2To SO3Conversion ratio；
M --- boiler fired coal amount, t/h；
Sar--- As-received sulfur content in fire coal, %；
q4--- the heat loss of imperfect solid combustion of boiler, %；
Q --- flue gas flow, m3/h；
Step 5 carries out alkali sulphur ratio CA/SCalculating:
In formula:--- gas cooler entrance SO3Concentration, mg/m3；
CA--- alkaline metal oxide content, mg/m are converted in ash3；
Step 6 carries out flue and heat-exchanging tube bundle that coal-burning power plant's air preheater outlet is exported to flue gas deep cooler
Local coefficient m calculating:
In formula: k --- gas-solid impact factor, dimensionless；
A --- flue gas passes through the average angle turned over when different polymorphic structures, °；
S1--- flue gas passes through the flow area before different polymorphic structures, m2；
S2--- flow area of the flue gas after different polymorphic structures, m2；
Step 7, the calculating for carrying out the uneven accumulation factor M in flow field:
In formula: mi--- flue gas passes through local coefficient when different polymorphic structures；
The uneven accumulation factor M in flow field is a kind of criterion for evaluating efficiency loss, carrys out evaluation of flue gas with this and exists
When by special-shaped through-flow and Pipe bundle structure, the accumulation of efficiency loss.
Step 8, alkali sulphur absorb low-temperature corrosion preventing control method:
Control alkali sulphur ratio CA/SOnly realize grey efficient absorption SO in flue gas3Or H2SO4Necessary condition, alkali sulphur ratio is bigger,
Alkali sulfur absorption rate is higher；And controlling the uneven accumulation factor M in flow field is to determine grey efficient absorption SO3Or H2SO4Adequate condition,
Within the specified scope, the uneven accumulation factor in flow field is smaller, and alkali sulfur absorption rate is higher；
As long as designing and running time control alkaline sulphur ratio C in flue gas deep coolerA/SGreater than critical value 0.5, and make uneven
When accumulation factor M control is in 15~30 ranges, grey efficient absorption SO in flue gas can be realized3Or H2SO4, significantly reduce flue gas
The low-temperature corrosion rate of deep cooler, on the one hand, realize the safe and highly efficient operation of flue gas deep cooler, on the other hand, ash
Absorb SO3Or H2SO4Afterwards, cooperation-removal ash and SO will be realized in subsequent electrostatic precipitator3Or H2SO4Purpose；
As the alkali sulphur ratio CA/SWhen being not greater than critical value 0.5, the coal different to alkaline metal oxide content is carried out
Mixture, or alkaline metal oxide powder is uniformly sprayed directly into flue gas, improve the alkalinous metal that coal-burning power plant uses coal
Oxide content realizes that high-efficient alkali sulphur absorbs to improve the alkali sulphur ratio for using coal, and effectively prevention and control flue gas deep cooler
Low-temperature corrosion；
When the stream of flue and heat-exchanging tube bundle that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports
When the uneven accumulation factor M in field is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and even flow field is set
Meter reduces flue gas and passes through the average angle turned over when different polymorphic structures, and keeps smoke-filling movement, velocity field and ash particle dense
Degree field energy enough has the function of that collaboration improves alkali sulfur absorption rate.
For coal-powder boiler, As-received sulphur is converted into SO in the fire coal2Conversion ratio η1Take 90%；The SO2To
SO3Conversion ratio η2Take 1.8%-2.2%.
The alkaline metal oxide powder directly uniformly sprayed into flue gas is CaO or MgO powder.
As the alkali sulphur ratio CA/SWhen being not greater than critical value 0.5, the coal different to alkaline metal oxide content is carried out
Mixture refers to the low coal of the high coal of alkalinous metal content and alkalinous metal content carrying out ratio coal blending, will use coal
Alkali sulphur ratio is increased to 0.5 or more.
When the stream of flue and heat-exchanging tube bundle that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports
When the uneven accumulation factor M in field is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and even flow field is set
Meter refers to sectional dimension, the shape, angle of turn for changing flue, increases deflector, so that even flow field.
When the stream of flue and heat-exchanging tube bundle that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports
When the uneven accumulation factor M in field is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and even flow field is set
Meter refers to structure, shape and the sectional dimension for changing heat exchanger, redesigns enhanced heat transfer component, or changes augmentation of heat transfer member
The structure of part, so that even flow field.
Parameter definition theoretical foundation of the invention is as follows:
When flue gas depth be cooled to sulphuric acid dew point and it is following when, ash particle and SO in flue gas3Or H2SO4Gas-liquid-solid occurs
Alkali sulphur absorbs, and ash particle partial size increases and specific resistance reduces, and is then removed in electrostatic precipitator, to realize SO3Or
H2SO4Effective removing.Realize that the controllable key of low-temperature corrosion is SO in flue gas3Or H2SO4Effective removing.When in flue gas
Ash particle and SO3Or H2SO4When realizing that efficient alkali sulphur absorbs, it is controllable that flue gas deep cooler low-temperature corrosion can be realized.By alkali
Sulphur absorption mechanism it is found that ash particle to SO3Or H2SO4Absorption be mainly grey neutral and alkali ingredient absorption, including object
Reason absorption and chemical reaction, and based on chemical reaction, these alkaline components are mainly alkali metal oxide (such as Na2O、K2O etc.)
With alkaline earth oxide (such as CaO, MgO).Alkali sulphur ratio is bigger, and alkali sulfur absorption rate is higher.Alkali sulphur is than taking off from the conceptive of matter
Show the mechanism that alkali sulphur absorbs, provides a more accurate and reliable evaluation method and index for the absorption of gas-liquid solid caustic soda sulphur.
However found in the actual moving process of flue gas deep cooler, control alkali sulphur is than only realizing that ash is high in flue gas
Effect absorbs SO3Or H2SO4Necessary condition, the simple alkali sulphur ratio that controls can not achieve SO3Or H2SO4Complete alkali sulphur absorb.One
Aspect, there are polymorphic structures for the flue and heat-exchanging tube bundle exported due to air preheater outlet to flue gas deep cooler, so that
Smoke-filling movement, velocity field and dust concentration field distribution are uneven, reduce the validity of alkali sulphur absorption；On the other hand, due to
Flue shuts off the different particle size distribution of ash particle in face, influences ash particle efficient absorption SO in flue gas3Or H2SO4.Flow field is uneven
Accumulation factor is a kind of criterion for evaluating efficiency loss, carrys out evaluation of flue gas by special-shaped through-flow and Pipe bundle structure with this
When, the accumulation of efficiency loss, the uneven accumulation factor in flow field is smaller, and alkali sulfur absorption rate is higher.Therefore, flow field is controlled
Uneven accumulation factor is to determine grey efficient absorption SO3Or H2SO4Adequate condition.
As long as designing and run time control alkaline sulphur ratio in flue gas deep cooler is greater than critical value, and makes unevenly to accumulate system
In a certain range, ash particle efficient absorption SO in flue gas can be realized in number control3Or H2SO4, it is cooling to significantly reduce flue gas depth
The low-temperature corrosion rate of device realizes that flue gas deep cooler corrodes prevention and control.
Claims (6)
1. alkali sulphur absorbs low-temperature corrosion preventing control method when a kind of coal-fired flue-gas depth is cooling, it is characterised in that: this method include with
Lower step:
Step 1 carries out grey neutral and alkali metal oxide Fe according to national standard GB/T1574-2007 " coal ash analysis method "2O3、
CaO、MgO、Na2O and K2The test of O mass content；
Step 2 carries out converting the sum of the mass percent of alkaline metal oxide Wt in ashACalculating:
In formula:--- Fe in ash2O3Mass content, %；
WtCaO--- CaO mass content in ash, %；
WtMgO--- MgO mass content in ash, %；
--- Na in ash2O mass content, %；
--- K in ash2O mass content, %；
Step 3 carries out converting alkaline metal oxide content C in ashACalculating:
CA=CD×WtA
In formula: CD--- gas cooler entrance dust concentration, mg/m3；
WtA--- the sum of the mass percent of alkaline metal oxide, % are converted in ash；
Step 4 carries out gas cooler entrance SO3ConcentrationCalculating:
In formula: η1--- As-received sulphur is converted into SO in fire coal2Conversion ratio；
η2——SO2To SO3Conversion ratio；
M --- boiler fired coal amount, t/h；
Sar--- As-received sulfur content in fire coal, %；
q4--- the heat loss of imperfect solid combustion of boiler, %；
Q --- flue gas flow, m3/h；
Step 5 carries out alkali sulphur ratio CA/SCalculating:
In formula:--- gas cooler entrance SO3Concentration, mg/m3；
CA--- alkaline metal oxide content, mg/m are converted in ash3；
Step 6, the office for carrying out flue and heat-exchanging tube bundle that coal-burning power plant's air preheater outlet is exported to flue gas deep cooler
The calculating of portion's Coefficient m:
In formula: k --- gas-solid impact factor, dimensionless；
α --- flue gas passes through the average angle turned over when different polymorphic structures, °；
S1--- flue gas passes through the flow area before different polymorphic structures, m2；
S2--- flow area of the flue gas after different polymorphic structures, m2；
Step 7, the calculating for carrying out the uneven accumulation factor M in flow field:
In formula: mi--- flue gas passes through local coefficient when different polymorphic structures；
The uneven accumulation factor M in flow field is a kind of criterion for evaluating efficiency loss, carrys out evaluation of flue gas with this and is passing through
When special-shaped through-flow and Pipe bundle structure, the accumulation of efficiency loss；
Step 8, alkali sulphur absorb low-temperature corrosion preventing control method:
Control alkali sulphur ratio CA/SOnly realize grey efficient absorption SO in flue gas3Or H2SO4Necessary condition, alkali sulphur ratio is bigger, alkali sulphur
Absorptivity is higher；And controlling the uneven accumulation factor M in flow field is to determine grey efficient absorption SO3Or H2SO4Adequate condition, advising
Determine in range, the uneven accumulation factor in flow field is smaller, and alkali sulfur absorption rate is higher；
As long as designing and running time control alkaline sulphur ratio C in flue gas deep coolerA/SGreater than critical value 0.5, and make unevenly to accumulate
When coefficient M control is in 15~30 ranges, i.e., grey efficient absorption SO in realization flue gas3Or H2SO4, it is cold to significantly reduce flue gas depth
But the low-temperature corrosion rate of device, on the one hand, realize the safe and highly efficient operation of flue gas deep cooler, on the other hand, ash absorbs SO3
Or H2SO4Afterwards, cooperation-removal ash and SO will be realized in subsequent electrostatic precipitator3Or H2SO4Purpose；
As the alkali sulphur ratio CA/SWhen being not greater than critical value 0.5, the coal different to alkaline metal oxide content is mixed
Match, or uniformly spray alkaline metal oxide powder directly into flue gas, improves the alkalinous metal oxygen that coal-burning power plant uses coal
Compound content realizes that high-efficient alkali sulphur absorbs to improve the alkali sulphur ratio for using coal, and effective prevention and control flue gas deep cooler
Low-temperature corrosion；
When the flow field of flue and heat-exchanging tube bundle that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports not
When uniform accumulation factor M is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and even flow fieldization designs, is subtracted
Small flue gas passes through the average angle turned over when different polymorphic structures, and makes smoke-filling movement, velocity field and ash particle concentration field
Can have the function of that collaboration improves alkali sulfur absorption rate.
2. alkali sulphur absorbs low-temperature corrosion preventing control method, feature when a kind of coal-fired flue-gas depth cooling as described in claim 1
Be: for coal-powder boiler, As-received sulphur is converted into SO in the fire coal2Conversion ratio η1Take 90%；The SO2To SO3's
Conversion ratio η2Take 1.8%-2.2%.
3. alkali sulphur absorbs low-temperature corrosion preventing control method, feature when a kind of coal-fired flue-gas depth cooling as described in claim 1
Be: the alkaline metal oxide powder directly uniformly sprayed into flue gas is CaO or MgO powder.
4. alkali sulphur absorbs low-temperature corrosion preventing control method, feature when a kind of coal-fired flue-gas depth cooling as described in claim 1
It is: as the alkali sulphur ratio CA/SWhen being not greater than critical value 0.5, the coal different to alkaline metal oxide content is mixed
Match, refers to and the low coal of the high coal of alkalinous metal content and alkalinous metal content is subjected to ratio coal blending, the alkali of coal will be used
Sulphur ratio is increased to 0.5 or more.
5. alkali sulphur absorbs low-temperature corrosion preventing control method, feature when a kind of coal-fired flue-gas depth cooling as described in claim 1
Be: when the flow field of flue and heat-exchanging tube bundle that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports not
When uniform accumulation factor M is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and even flow fieldization designs, is
Refer to sectional dimension, the shape, angle of turn for changing flue, increases deflector, so that even flow field.
6. alkali sulphur absorbs low-temperature corrosion preventing control method, feature when a kind of coal-fired flue-gas depth cooling as described in claim 1
Be: when the flow field of flue and heat-exchanging tube bundle that the air preheater outlet from coal-burning power plant to flue gas deep cooler exports not
When uniform accumulation factor M is greater than control range, numerical simulation is carried out to flue and heat exchanger flow field and even flow fieldization designs, is
Refer to structure, shape and the sectional dimension for changing heat exchanger, redesigns enhanced heat transfer component, or change the knot of enhanced heat transfer component
Structure, so that even flow field.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1114731A (en) * | 1995-03-20 | 1996-01-10 | 刘曾春 | Vortex-impact-type smoke purifier antiseptic making technology and desulphurizing method |
| CN103657391A (en) * | 2013-12-11 | 2014-03-26 | 中能东讯新能源科技(大连)有限公司 | Bidirectional semidry-method desulfuration device for tail flue of boiler |
| CN104484578A (en) * | 2014-12-31 | 2015-04-01 | 浙江菲达环保科技股份有限公司 | Low-low-temperature electric dust remover ash sulfur ratio computing method and corrosion degree control method |
| CN104676620A (en) * | 2015-02-11 | 2015-06-03 | 杭州华电能源工程有限公司 | Flue gas processing system and flue gas processing method capable of enabling low-low temperature electrostatic precipitation to be combined with water pollination type GGH (Gas Gas Heater) |
| CN106166437A (en) * | 2016-07-21 | 2016-11-30 | 南京西普环保科技有限公司 | A kind of cement kiln flue gas desulphurization system and method |
-
2016
- 2016-12-30 CN CN201611255350.8A patent/CN106731465B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1114731A (en) * | 1995-03-20 | 1996-01-10 | 刘曾春 | Vortex-impact-type smoke purifier antiseptic making technology and desulphurizing method |
| CN103657391A (en) * | 2013-12-11 | 2014-03-26 | 中能东讯新能源科技(大连)有限公司 | Bidirectional semidry-method desulfuration device for tail flue of boiler |
| CN104484578A (en) * | 2014-12-31 | 2015-04-01 | 浙江菲达环保科技股份有限公司 | Low-low-temperature electric dust remover ash sulfur ratio computing method and corrosion degree control method |
| CN104676620A (en) * | 2015-02-11 | 2015-06-03 | 杭州华电能源工程有限公司 | Flue gas processing system and flue gas processing method capable of enabling low-low temperature electrostatic precipitation to be combined with water pollination type GGH (Gas Gas Heater) |
| CN106166437A (en) * | 2016-07-21 | 2016-11-30 | 南京西普环保科技有限公司 | A kind of cement kiln flue gas desulphurization system and method |
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