CN104976637B - Method for calculating cold air leakage amount of inlet of coal mill for thermal power generation boiler - Google Patents
Method for calculating cold air leakage amount of inlet of coal mill for thermal power generation boiler Download PDFInfo
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Abstract
The invention provides a method for calculating the cold air leakage amount of an inlet of a coal mill for a thermal power generation boiler. The method comprises the step that the cold air leakage amount of the inlet of the coal mill satisfies the formula: F1=Fh*(Th*Ch-Tr*Cr)/(T1*C1-Tr*Cr), wherein F1 is set to be the cold air leakage amount of the inlet of the coal mill, Fh is set to be the mixed air amount of the inlet of the coal mill, Th is set to be the temperature of mixed air of the inlet of the coal mill, Ch is set to be the constant-pressure specific heat capacity of the inlet of the coal mill, Tr is set to be the temperature of hot air of the inlet of the coal mill, Cr is set to be the constant-pressure specific heat capacity of the hot air of the inlet of the coal mill, T1 is set to be the temperature of cold air of the inlet of the coal mill, and C1 is set to be the constant-pressure specific heat capacity of the cold air of the inlet of the coal mill. The standard regulation quantity of an air door baffle at a cold air inlet of the coal mill of a direct blowing type coal pulverizing system is provided, the internal leakage amount of cold air of the direct blowing type coal pulverizing system is reduced, the drying capacity of the coal mill is increased, the exhaust gas temperature of the boiler is effectively lowered, and the standard regulation quantity of the air door baffle at the cold air inlet of the coal mill of the direct blowing type coal pulverizing system is acquired not through a test value any longer, so the stability and safety of a boiler combustion system are improved, and the regulation efficiency of the air door baffle at the cold air inlet of the coal mill of the direct blowing type coal pulverizing system is improved.
Description
First, technical field
Patent of the present invention is related to a kind of computational methods of coal pulverizer inlet cold wind leakage rate, especially a kind of to send out for firepower
The computational methods of the coal pulverizer inlet cold wind leakage rate in electric boiler.
2nd, background technology
The safety of thermal power plant unit operation and economy depend primarily on steam generator system, and affect steam generator system fortune
The factor of row safety and economy is the pulverized coal preparation system of boiler fired coal, and the task of thermal power plant pulverized coal preparation system is arranged to pot
Stove provides the coal dust that quality and quantity all meets combustion requirements.Existing thermal power generation corporations' coal dust preparation system mainly sets up separately to be put
For following several classes：（1）Middle storage low speed coal mill system；（2）Straight-blowing double-inlet and double-outlet steel ball coal mill system；（3）It is direct-firing
Medium-speed pulverizer system.Due to unit pulverized-coal system because its system arranges that relatively easy, reliability is high, it is strong to adapt to coal ability
Advantage is used widely；
For unit pulverized-coal system, coal pulverizer inlet cold wind leakage rate directly affects the drying capacity of coal pulverizer,
Cold wind leakage rate crosses the coal pulverizer inlet hot blast that senior general squeezes same volume, so as to cause direct-fired mill to dry out
Power is not enough, raises exhaust gas temperature, will affect boiler combustion stable when serious and safety, in each thermal power plant in blow-through
Formula pulverized coal preparation system drying capacity of pulverizer control adjustment aspect electric current aspect is primarily present following two problems：The direct-firing system of one
Powder system belongs to positive-pressure type pulverized coal preparation system, for the ball type pulverizer system, unit pulverized-coal system valve and baffle plate it is outer
Substantially, the performance of internal hemorrhage due to trauma problem is not obvious, it is difficult to inline diagnosis and maintenance for leakage problem；Its two simultaneously pressurized direct pulverizing coal system receive
Design condition affects, and cold wind pressure is higher than hot-blast pressure, thus brings cold wind caused by the abrasion of coal pulverizer inlet cold air damper to let out
Leakage quantity is big；
In order to ensure the safety of thermal power plant unit operation and improve its economy, to the mill in thermal power generation boiler
Coal machine entrance cold wind leakage rate is calculated and controlled tool to have very important significance, and thus be accordingly used in the coal-grinding in thermal power generation boiler
The computational methods of machine entrance cold wind leakage rate are a kind of important computational methods, be currently there are no a kind of for thermal power generation boiler
In coal pulverizer inlet cold wind leakage rate computational methods.
3rd, the content of the invention
In order to the purpose for overcoming above-mentioned technical disadvantages, patent of the present invention is to provide a kind of mill in thermal power generation boiler
The computational methods of coal machine entrance cold wind leakage rate, therefore stability and the safety of boiler combustion system are improved, improve blow-through
The regulation efficiency of formula pulverized coal preparation system coal pulverizer cold air inlet damper.
In order to achieve the above object, patent of the present invention is adopted the technical scheme that：
Application conditions：Direct-fired mill runs and coal pulverizer electric current is more than 25A and unit pulverized-coal system
Coal pulverizer inlet cold wind plate washer open degree feedback ＜ 3%；
Fl=Fh×（Th×Ch-Tr×Cr）/（Tl×Cl-Tr×Cr）,
Wherein：
Fl is set to coal pulverizer inlet cold wind leakage rate,
Fh is set to coal pulverizer inlet mixed air volume,
Th is set to coal pulverizer inlet mixing pathogenic wind-warm,
Ch is set to coal pulverizer inlet mixing wind specific heat at constant pressure,
Tr is set to coal pulverizer inlet hot blast temperature,
Cr is set to coal pulverizer inlet hot blast specific heat at constant pressure,
Tl is set to coal pulverizer inlet cold wind temperature,
Cl is set to coal pulverizer inlet cold wind specific heat at constant pressure；
In the present embodiment, direct-fired mill entrance dried medium specific heat at constant pressure C=1.319+3.013/
10^5 × T+2.118/10^7 × T^2-1.746/10^10 × T^3+5.863/10^14 × T^4-7.337/10^18 × T^5,
Wherein T is set to the real time dynamic measurement Celsius temperature that dried medium is respectively set to hot blast, mixing wind and cold wind
Value；
When T is set to the real time dynamic measurement celsius temperature scale that dried medium is mixing wind, Ch=1.319+3.013/10^5
×T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×T^4-7.337/10^18×T^5；
When wherein T is set to the real time dynamic measurement celsius temperature scale that dried medium is hot blast, Cr=1.319+3.013/10
^5×T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×T^4-7.337/10^18×T^5；
When wherein T is set to the real time dynamic measurement celsius temperature scale that dried medium is cold wind,
Cl=1.319+3.013/10^5×T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×
T^4-7.337/10^18×T^5；
In the present embodiment,
Fh is set to coal pulverizer inlet mixed air volume and is set to real time dynamic measurement value,
Th is set to coal pulverizer inlet mixing pathogenic wind-warm and is set to real time dynamic measurement value,
Tr is set to coal pulverizer inlet hot blast temperature and is set to real time dynamic measurement value,
Tl is set to coal pulverizer inlet cold wind temperature and is set to real time dynamic measurement value.
Due to devising the computational methods to direct-fired mill entrance cold wind leakage rate, there is provided direct-firing
The adjustment criteria amount of pulverized coal preparation system coal pulverizer cold air inlet damper, reduces leakage quantity in unit pulverized-coal system cold wind, improves
Drying capacity of pulverizer, effectively reduces exhaust gas temperature, is no longer worth to direct-fired mill by test cold
The adjustment criteria amount of wind inlet vane baffle plate, therefore stability and the safety of boiler combustion system are improved, improve direct-firing
The regulation efficiency of pulverized coal preparation system coal pulverizer cold air inlet damper.
The present invention is devised, the journey of the computational methods for the coal pulverizer inlet cold wind leakage rate in thermal power generation boiler
Sequence is set to be implanted in the DCS control system unit pulverized-coal system control modules of thermal power plant.
In technical scheme, selected parameter will meet the conservation of mass and heat of pulverized coal preparation system ventilation and keep
Constant condition, i.e.,：The conservation of mass：The summation of hot blast air quantity and cold wind air quantity into coal pulverizer is equal to the mixed air volume of coal pulverizer,
Heat conservation：Hot blast into coal pulverizer brings heat and cold wind into and brings the summation of heat into and is equal to the heat of coal pulverizer mixing wind.^
It is the implication of " power ", in all kinds of engineering calculation softwares such as：3.013/10^5 then it is expressed as 3.013/100000.
In the technical program, the air quantity, pathogenic wind-warm and specific heat at constant pressure to direct-fired mill is arranged attaches most importance to
Technical characteristic is wanted, in the technical field of the computational methods of the coal pulverizer inlet cold wind leakage rate in for thermal power generation boiler,
With novelty, creative and practicality, the term in the technical program all can be with patent text in the art
Offer and explain and understand.
4th, illustrate
With reference to embodiment, the present invention is further described, following examples are intended to illustrate rather than to this
The further restriction of invention.
One embodiment of the present invention, technical scheme,
Application conditions：Direct-fired mill runs and coal pulverizer electric current is more than 25A and unit pulverized-coal system
Coal pulverizer inlet cold wind plate washer open degree feedback ＜ 3%；
Fl=Fh×（Th×Ch-Tr×Cr）/（Tl×Cl-Tr×Cr）,
Wherein：
Fl is set to coal pulverizer inlet cold wind leakage rate,
Fh is set to coal pulverizer inlet mixed air volume,
Th is set to coal pulverizer inlet mixing pathogenic wind-warm,
Ch is set to coal pulverizer inlet mixing wind specific heat at constant pressure,
Tr is set to coal pulverizer inlet hot blast temperature,
Cr is set to coal pulverizer inlet hot blast specific heat at constant pressure,
Tl is set to coal pulverizer inlet cold wind temperature,
Cl is set to coal pulverizer inlet cold wind specific heat at constant pressure；
In the present embodiment, direct-fired mill entrance dried medium specific heat at constant pressure C=1.319+3.013/
10^5 × T+2.118/10^7 × T^2-1.746/10^10 × T^3+5.863/10^14 × T^4-7.337/10^18 × T^5,
Wherein T is set to the real time dynamic measurement Celsius temperature that dried medium is respectively set to hot blast, mixing wind and cold wind
Value；
When T is set to the real time dynamic measurement celsius temperature scale that dried medium is mixing wind, Ch=1.319+3.013/10^5
×T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×T^4-7.337/10^18×T^5；
When wherein T is set to the real time dynamic measurement celsius temperature scale that dried medium is hot blast, Cr=1.319+3.013/10
^5×T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×T^4-7.337/10^18×T^5；
When wherein T is set to the real time dynamic measurement celsius temperature scale that dried medium is cold wind,
Cl=1.319+3.013/10^5×T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×
T^4-7.337/10^18×T^5；
In the present embodiment,
Fh is set to coal pulverizer inlet mixed air volume and is set to real time dynamic measurement value,
Th is set to coal pulverizer inlet mixing pathogenic wind-warm and is set to real time dynamic measurement value,
Tr is set to coal pulverizer inlet hot blast temperature and is set to real time dynamic measurement value,
Tl is set to coal pulverizer inlet cold wind temperature and is set to real time dynamic measurement value；
T value is obtained by the centigrade real time dynamic measurement to hot blast, mixing wind and cold wind, Ch, Cr is calculated
With Cl values, Fh, Th, Tr and Tl value is obtained by real time dynamic measurement, be calculated Fl values, thermal power plant is controlled by Fl values
The combustion system of the boiler of unit.
1000MW unit direct-fired mill model BBD4360 coal pulverizers
| Project | Unit | Technical parameter（Design coal） |
| Coal pulverizer model | BBD-4360 | |
| Pulverizer capacity（HGI=50, H2O=8%, 75% pass through 200 mesh sieves） | t/h | 70 |
| Cylinder effective diameter | mm | 4250 |
| Cylinder effective length | mm | 6140 |
| Drum speed | r/min | 16 |
| Cylinder dischargeable capacity | m3 | 87.1 |
| Maximum ball load | t | 92 |
| Sealing air quantity | kg/h | 4500 |
Before this enforcement is provided without, it is impossible to online to estimate coal pulverizer inlet cold wind slip, after using the present embodiment, profit
Find that coal pulverizer inlet cold wind slip is for about 10-15% or so with this method, by changing to multiple stage coal pulverizer inlet cold-air flap
Make, cold wind slip is reduced to into less than 3%, make exhaust gas temperature reduce about 3 DEG C or so, unit generation coal consumption is reduced about
0.4g/kWh, improves unit overall economy quality.
Patent of the present invention has lower feature：
1st, due to devising the computational methods to direct-fired mill entrance cold wind leakage rate, there is provided blow-through
The adjustment criteria amount of formula pulverized coal preparation system coal pulverizer cold air inlet damper, reduces leakage quantity in unit pulverized-coal system cold wind, carries
High drying capacity of pulverizer, effectively reduces exhaust gas temperature, is no longer worth to direct-fired mill by test
The adjustment criteria amount of cold air inlet damper, therefore stability and the safety of boiler combustion system are improved, improve blow-through
The regulation efficiency of formula pulverized coal preparation system coal pulverizer cold air inlet damper.
2nd, due to devising the computational methods to direct-fired mill entrance cold wind leakage rate, by dynamic in real time
State is measured, and obtains the coal pulverizer inlet cold wind leakage rate of Real-time and Dynamic, improves boiler combustion system reliability of operation energy.
3rd, the restriction of numerical range has been carried out to planform due to devising, has made numerical range be set to patent of the present invention
Technical scheme in technical characteristic, be not to be calculated by formula or by the limited number of time technical characteristic that draws of test, test table
The technical characteristic of the bright numerical range achieves good technique effect.
4th, due to devising the technical characteristic of patent of the present invention, the work of set in the independent of technical characteristic and each other
With, being shown by testing, the property indices of patent of the present invention are set to setting at least to for existing property indices
1.7 times, there is good market value by assessment.
Above-described embodiment is the coal pulverizer inlet cold wind leakage rate in thermal power generation boiler provided by the present invention
Computational methods a kind of way of realization, according to scheme provided by the present invention other deform, increase or reduce and be therein
Composition or step, or the present invention is belonged to into the protection model of the present invention for other technical fields close with the present invention
Enclose.
Claims (2)
1. a kind of computational methods of the coal pulverizer inlet cold wind leakage rate in thermal power generation boiler；It is characterized in that：Its step
Suddenly it is：
Application conditions：Direct-fired mill runs and coal pulverizer electric current is more than 25A and unit pulverized-coal system coal-grinding
Machine entrance cold wind plate washer open degree feedback ＜ 3%；
Fl=Fh×（Th×Ch-Tr×Cr）/（Tl×Cl-Tr×Cr）,
Wherein：
Fl is set to coal pulverizer inlet cold wind leakage rate,
Fh is set to coal pulverizer inlet mixed air volume,
Th is set to coal pulverizer inlet mixing pathogenic wind-warm,
Ch is set to coal pulverizer inlet mixing wind specific heat at constant pressure,
Tr is set to coal pulverizer inlet hot blast temperature,
Cr is set to coal pulverizer inlet hot blast specific heat at constant pressure,
Tl is set to coal pulverizer inlet cold wind temperature,
Cl is set to coal pulverizer inlet cold wind specific heat at constant pressure；
Direct-fired mill entrance dried medium specific heat at constant pressure C=1.319+3.013/10^5 × T+2.118/10^
7 × T^2-1.746/10^10 × T^3+5.863/10^14 × T^4-7.337/10^18 × T^5,
Wherein T is set to the real time dynamic measurement celsius temperature scale that dried medium is respectively set to hot blast, mixing wind and cold wind；
When T is set to the real time dynamic measurement celsius temperature scale that dried medium is mixing wind, Ch=1.319+3.013/10^5 × T+
2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×T^4-7.337/10^18×T^5；
When wherein T be set to dried medium be hot blast real time dynamic measurement celsius temperature scale, Cr=1.319+3.013/10^5 ×
T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×T^4-7.337/10^18×T^5；
When wherein T is set to the real time dynamic measurement celsius temperature scale that dried medium is cold wind,
Cl=1.319+3.013/10^5×T+2.118/10^7×T^2-1.746/10^10×T^3+5.863/10^14×T^4-
7.337/10^18×T^5；
Fh is set to coal pulverizer inlet mixed air volume and is set to real time dynamic measurement value,
Th is set to coal pulverizer inlet mixing pathogenic wind-warm and is set to real time dynamic measurement value,
Tr is set to coal pulverizer inlet hot blast temperature and is set to real time dynamic measurement value,
Tl is set to coal pulverizer inlet cold wind temperature and is set to real time dynamic measurement value.
2. computational methods of the coal pulverizer inlet cold wind leakage rate in thermal power generation boiler according to claim 1,
It is characterized in that：The program of the computational methods for the coal pulverizer inlet cold wind leakage rate in thermal power generation boiler is set to implantation
To in the DCS control system unit pulverized-coal system control modules of thermal power plant.
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