CN107292006A - The startup computational methods and system of a kind of super critical boiler - Google Patents
The startup computational methods and system of a kind of super critical boiler Download PDFInfo
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- 238000000205 computational method Methods 0.000 title claims abstract description 16
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- 238000004134 energy conservation Methods 0.000 claims abstract description 13
- 238000009825 accumulation Methods 0.000 claims abstract description 11
- 238000004458 analytical method Methods 0.000 claims abstract description 4
- 239000000779 smoke Substances 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 44
- 238000001816 cooling Methods 0.000 claims description 26
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- 238000009826 distribution Methods 0.000 claims description 22
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- 239000003517 fume Substances 0.000 claims description 7
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Abstract
The invention discloses the startup computational methods and system of a kind of super critical boiler, calculated first for hearth combustion：Burner hearth is divided into radiation heat transfer area and two, radiation and convection area part, two parts calculated respectively, different combustion rate lower hearth exit gas temperatures, burner hearth heat absorption percentage and flue gas specific heat is obtained；Secondly exchange heat and calculate for boiler heating surface：On the basis of intraductal working medium side simplifies with pipe outer flue gas side flowing heat-transfer character progress analysis in heating surface during to boiler startup, the distributed parameter model changed using consideration thermal parameter with position coordinates, according to mass-conservation equation, momentum conservation equation, energy conservation equation, metal accumulation of heat equation and the mathematical modeling for supplementing Temperature of Working in establishing equation start-up course, pressure, enthalpy, heating surface metal temperature and smoke temperature change rule, and solved.Different boiler start-up system layout patterns can be calculated and compared by the present invention, provide the user optimal boiler start-up system.
Description
Technical field
The invention belongs to boiler startup field, and in particular to the startup computational methods and system of a kind of super critical boiler.
Background technology
Boiler start-up system and Steam Turbine Bypass System are installed on supercritical unit, the spirit of supercritical unit can be greatly improved
Activity and economic benefit.How optimal boiler start-up system is designed according to the investment situation and power plant's operational mode of user, made
Heat loss is minimum during must starting；Which type of boosting curve should be taken during boiler startup, can just make the thermal stress of heavy wall element
And the metal wall surface temperature such as superheater, reheater is in tolerance band.While meeting conditions above, operations staff also needs to
Know that the matching relationship of boosting curve and combustion rate curve could be so that boiler be boosted according to predetermined boosting curve.Solve
The basis of above mentioned problem is the computational methods that accurate simulation boiler startup process is capable of in research and development.Existing many of computational methods are fitted
Dynamic characteristic when having minor variations near steady-state operation point for boiler is calculated, when being calculated for start-up course error compared with
Greatly.
The content of the invention
It is above-mentioned existing to overcome it is an object of the invention to provide the startup computational methods and system of a kind of super critical boiler
Different boiler start-up system layout patterns can be calculated and compared by the defect that technology is present, the present invention, provide the user optimal
Boiler start-up system.
To reach above-mentioned purpose, the present invention is adopted the following technical scheme that：
A kind of startup computational methods of super critical boiler, comprise the following steps：
1) hearth combustion is calculated：Burner hearth is divided into radiation heat transfer area and two, radiation and convection area part, respectively to two portions
Divide and calculated, obtain different combustion rate lower hearth exit gas temperatures, burner hearth heat absorption percentage and flue gas specific heat；
2) boiler heating surface heat exchange is calculated：During to boiler startup in heating surface intraductal working medium side with managing outer fume side
On the basis of the progress analysis of flowing heat transfer characteristic simplifies, the distributed constant mould changed using consideration thermal parameter with position coordinates
Type, starts according to mass-conservation equation, momentum conservation equation, energy conservation equation, metal accumulation of heat equation and supplement establishing equation
During Temperature of Working, pressure, enthalpy, the mathematical modeling of heating surface metal temperature and smoke temperature change rule, and asked
Solution.
Further, the radiation heat transfer area is burner hearth bottom to the region between burner, and its heat transfer type is radiation
Heat exchange, flue gas and the heat convection of furnace wall are not considered；The radiation and convection area is more than radiation heat transfer area until furnace outlet
Part, the heat transfer of area's flame and water-cooling wall is based on radiation heat transfer, while considering heat convection caused by flow of flue gas.
Further, step 1) in radiation heat transfer area is calculated, including：
The Radiant exothermicity of radiation heat transfer area flame and furnace wall is：
Radiant exothermicity between flame and radiation heat transfer area outlet is：
High-temperature flue gas is in the equation of heat balance of radiation heat transfer area heat release：
More than in three formulas, CsFor flame and the radiation heat transfer coefficient of furnace wall, εfFor total emissivity, radiation heat transfer area furnace wall
Heat exchange area Afw=2 (W+D) Lf+ WD, radiation heat transfer area outlet heat exchange area AI=WD, W are that stove is wide, and D is that stove is deep, LfFor
Radiation heat transfer area height, x is ascent of the flame to furnace wall, and μ is that flame-gas radiation exchanges ratio, TfWith TwRespectively radiate
Heat transfer zone flame temperature and furnace wall temperature,To consider the errors in radiation heat transfer area after radiation loss, BjTo calculate fuel
Consumption, QlTo send into the efficient heat of burner hearth, h on the basis of one kilogram of calculating fuelfoFor radiation heat transfer area exiting flue gas enthalpy
Value；
According to high-temperature flue gas in the equation of heat balance of radiation heat transfer area heat release, it can be calculated by successive approximation method and obtain spoke
Penetrate the temperature and enthalpy of heat transfer zone exiting flue gas.
Further, step 1) in radiation and convection area is calculated, including：
It is Q according to the radiant heat flux of radiation heat transfer area outletICalculating the total hot-fluid into radiation and convection area is：
Qri=Yghfo+QI
The Radiant exothermicity of flue gas and tweer is：
Qrw=αrArwx1Δθ
Radiant exothermicity between flue gas and radiation and convection area outlet is：
QII=αrAIIx2Δθ
In the formula of the above three, average heat transfer temperature and pressure Δ θ is expressed as：
Always heat exchange amount is：
Qr=Qrw+QII+Qc
Therefore the hot-fluid of furnace outlet is：
Qro=Qri-Qr
Exiting flue gas enthalpy is accordingly：
Furnace outlet gas temperature θ is determined by the corresponding relation of flue-gas temperature and enthalpyroAfterwards, you can try to achieve burner hearth heat absorption hundred as the following formula
Divide ratio and flue gas specific heat：
Burner hearth heat absorption percentage be：
Flue gas specific heat is：
Wherein：hfoFor radiation heat transfer area exiting flue gas enthalpy, αrFor radiation and convection area flue gas and the radiation heat transfer coefficient of furnace wall,
Δ θ is average heat transfer temperature and pressure, θfFor radiation and convection area flame temperature, θroFor flue gas temperature of hearth outlet, θwFor radiation and convection
Area's internal protecting wall temperature, x1For ascent of the flue gas to furnace wall, radiation and convection area furnace wall heat exchange area Arw=2 (W+D) Lr, wherein Lr
For radiation and convection section length, x2For ascent of the flue gas to radiation and convection area outlet, radiation and convection area outlet heat exchange area AI
=AII, αcFor convection transfer rate, AwFor heat convection area, Q is the total amount of heat for entering burner hearth, θadFor adiabatic combustion temperature.
Further, step 2) in when deriving intraductal working medium and HEAT TRANSFER LAW, make following basic assumption：
A) assume that parallel transistor heating power waterpower is uniform, the heated of all parallel connection tube banks is represented with a heat pipe and is flowed
Situation；
B) the interior outside of wall peripherally equably neither endothermic nor exothermic；
C) consider that metal pipe-wall is very thin, therefore do not consider the radial direction thermal resistance of metallic walls, and be along the thermal resistance of metal axial
It is infinitely great；
D) medium is only exchanged heat with metallic walls in radial direction, without considering axially heat exchange；
E) Temperature of Working and VELOCITY DISTRIBUTION are uniform in same section, and medium only flows vertically in pipe, nothing
Internal circulation.
Further, based on assumed above, quality continuity equation is expressed as：
In formula：M-working medium flow, kg/s；
L-flow direction coordinate, m；
F-conduit cross-sectional area, m2；
ρ-working medium density, kg/m3；
T-time, s；
Energy conservation equation：
In formula：q2- the unit interval, unit length tube wall was to refrigerant heat transfer amount, W/m；
H-working medium enthalpy, J/kg；
mwWorking medium quality, m in-unit pipe rangew=ρ F, kg/m；
Due to dh=cwD θ, energy conservation equation can also be expressed as：
In formula：cw- working medium specific heat capacity, J/ (kg K)；
θ-Temperature of Working, DEG C；
Momentum conservation equation：
In formula：U-refrigerant flow rate, m/s；
P-power pressure, Pa；
β-pipe inclination angle, rad；
fpThe pipe range friction pressure drop of-unit, Pa；
The thermal balance of unit length metal pipe-wall is considered in calculating process, metal accumulation of heat equation is obtained：
In formula：mM- unit pipe range metal quality, kg/m；
cM- metal specific heat holds, J/ (kg K)；
θM- metal temperature, DEG C；
q1- unit interval flue gas is to the heat output of unit length metal pipe-wall, W/m；
q2- the unit interval, unit length metal pipe-wall was to the heat output of working medium, W/m；
q1、q2Determined respectively according to fume side and working medium side convection heat transfer' heat-transfer by convection equation：
q1=αGF1(θG-θM)
q2=α F2(θM-θ)
In formula：αG- flue gas is to the metal pipe-wall coefficient of heat transfer, W/ (m2K)；
α-working medium convection transfer rate, W/ (m2K)；
F1- unit tube long metal pipe wall external surface area, m2；
F2- unit tube long metal pipe wall internal surface area, m2；
θG- flue-gas temperature, DEG C.
To feed-tank, feedwater piping, economizer, water wall section tube wall metal temperature, due to working medium pair in these parts
The coefficient of heat transfer of metal inner surface is very big, it is believed that metal temperature is identical with Temperature of Working, and to superheater, reheater section gold
Belong to temperature, then must take into consideration the difference of Temperature of Working and metal temperature, and by solving the tube wall temperature institute of consideration metal accumulation of heat
The differential equation that follows obtains the heating surface metal temperature of start-up course not in the same time, to boiler Gas Parameters everywhere, according to working as
Layer combustion rate calculates the flue gas flow of the moment furnace outlet, temperature, specific heat capacity parameter during preceding calculating, and the moment flue gas is in mistake
The energy conservation equation that Temperature Distribution at hot device, reheater and economizer part is met by flue gas is solved, flue gas flow, ratio
Thermal capacitance then thinks identical with furnace outlet.
A kind of startup computing system for the super critical boiler for realizing the above method, including：
Combustion module：Flue gas temperature of hearth outlet, exhaust gas volumn and cigarette for calculating the hearth combustion under different combustion rates
Gas specific heat and burner hearth heat absorption percentage；
Input module：For reading in data file, the data file includes the detailed of boiler general structure and each part
Physical dimension, starts the setting value of initial time boiler working medium, the distribution of flue gas thermal parameter and start-up course everywhere；
Geometry computing module：For according to data in data file, being calculated each modular construction size of boiler
Calculate geometric parameter required during the heat transfer of these part mobiles；
Fluid interchange calculates primary module：For to the flowing of a layer boiler start-up system all parts is passed during difference in start-up course
Enthalpy drop of the steam in high pressure cylinder is calculated after enthusiasm condition and steam turbine red switch；
Burn computing module：For the method for operation according to steam-water separator to be to water-cooling wall import working medium flow and saves coal
Working medium flow is calculated in device, burner hearth heat absorption percentage, flue gas flow, stove when then calculating current corresponding to layer combustion rate
Thorax exit gas temperature and specific heat capacity, burner hearth when layer combustion rate lower hearth caloric receptivity is with 100% combustion rate when finally calculating current
The ratio of caloric receptivity；
Flow circulation module：For calculating feed-tank to boiler component flowing heat transfer between economizer, and according to the conservation of mass
Principle, layer water-cooling wall entrance feedwater flow during current calculating；
Water-cooling wall computing module：For calculating water-cooling wall working medium enthalpy, pressure distribution and the hydrophobic enthalpy of steam-water separator；
First crosses, reheater computing module：For calculating when no steam flows into superheater system by steam-water separator
Superheater system closes reheater system flue gas, Working fluid flow heat transfer and metal pipe-wall Temperature Distribution；
Second crosses, reheater computing module：Overheated when thering is steam to flow into superheater system by steam-water separator for calculating
Device system and reheater systematic working medium, flow of flue gas heat transfer, metal pipe-wall Temperature Distribution and from time of ignition to layer when calculating
Medium-loss, thermal loss.
Further, the furnace outlet flue gas temperature of the hearth combustion under obtained different combustion rates is calculated in combustion module
Degree, exhaust gas volumn and flue gas specific heat and burner hearth heat absorption percentage, numerical value and beginning and ending time together with the constant combustion rate of input are constituted
The burning data input value that burning computing module is called.
Further, it is corresponding that the geometric parameter calculated in geometry computing module each calculates grid including each part of boiler
Pipe inner and outer surfaces product, volume and metal quality.
Further, according to the principle of mass conservation in Water flow-path computing module, layer water-cooling wall entrance feedwater during current calculating
Flow YfwFor：
Yfw=Ycy-Yxh+YBP+Yp(1)+Yp(2)+Yp(3)
In formula：Ycy--- deaerator storage tank rate of discharge, kg/s；
Yxh--- the layer hydrophobic recirculating mass of steam-water separator, kg/s during current calculating；
YBP--- layer high pressure bypass valve injection flow rate during a upper calculating, determined in the first mistake, reheater computing module, kg/
s；
YP(1)、YP(2)、YP(3) --- layer superheater and each injection point injection flow rate of reheater, kg/s during a upper calculating.
Compared with prior art, the present invention has following beneficial technique effect：
The present invention, which is developed, can simulate boiler cold-state, warm state, the computational methods of hot starting, hot start process, and this method can be to not
It is calculated and compared with boiler start-up system layout pattern, provides the user optimal boiler start-up system, while this method can
The different parts metals Temperature Distributions of each moment boiler during starting are calculated, and flow through inside and outside Temperature of Working, the enthalpy of each part
Distribution value, considers start-up course working medium and thermal loss situation, is provided for power plant operations staff from ignition of the boiler to minimum
Optimum start-up curve between DC load.
The start-up course of the correct analog DC boiler of present system energy, the boiler startup time is shorter, and payment for initiation is used and opened
The fewer but too fast startup of heat loss can cause excessive heat should in header and steam-water separator uniform thickness wall elements during dynamic
Power, optimal pot just can be provided by means of starting computing system, heavy wall element thermal stress and durability analysis program for operations staff
Stove boosts and corresponding combustion rate change curve, so as on the premise of equipment safety is ensured, complete to start with the most short time
Process, farthest saves payment for initiation and uses and reduce working medium and thermal loss during startup.
Brief description of the drawings
Fig. 1 is main program of the present invention and major sub programs call graph；
Fig. 2 is cold start combustion rate and feedwater flow change curve in case study on implementation of the present invention；
Fig. 3 is cold start main steam pressure and high pressure turbine by valve opening change curve in case study on implementation of the present invention；
Fig. 4 is cold start steam-water separator water tank pressure history in case study on implementation of the present invention；
Fig. 5 is cold start pendant superheater import and export Temperature of Working change curve in case study on implementation of the present invention；
Fig. 6 is cold start finishing superheater outlet tube wall temperature change curve in case study on implementation of the present invention；
Fig. 7 is cold start low temperature superheater outlet tube wall temperature change curve in case study on implementation of the present invention.
Embodiment
The present invention is described in further detail below in conjunction with the accompanying drawings：
A kind of startup computational methods of super critical boiler, step is as follows：
1) hearth combustion is calculated：In order to calculate in start-up course different combustion rate lower hearth exit gas temperatures, it is flow, close
The parameter such as degree and specific heat, is divided into radiation heat transfer area and two, radiation and convection area part by burner hearth.Wherein radiation heat transfer area is burner hearth
Bottom to the region between burner, its heat transfer type is radiation heat transfer, and flue gas and the heat convection of furnace wall are not considered.Radiation pair
It is more than radiation heat transfer area until the part of furnace outlet to flow area, the heat transfer of area's flame and water-cooling wall using radiation heat transfer as
It is main, while heat convection caused by flow of flue gas must also be considered.
The Radiant exothermicity of radiation heat transfer area flame and furnace wall is：
Radiant exothermicity between flame and radiation heat transfer area outlet is：
High-temperature flue gas is in the equation of heat balance of radiation heat transfer area heat release：
More than in three formulas, CsFor flame and the radiation heat transfer coefficient of furnace wall, εfFor total emissivity, radiation heat transfer area furnace wall
Heat exchange area Afw=2 (W+D) Lf+ WD, radiation heat transfer area outlet heat exchange area AI=WD, W are that stove is wide, and D is that stove is deep, LfFor
Radiation heat transfer area height, x is ascent of the flame to furnace wall, and μ is that flame-gas radiation exchanges ratio, TfWith TwRespectively radiate
Heat transfer zone flame temperature and furnace wall temperature,To consider the errors in radiation heat transfer area after radiation loss, BjTo calculate fuel
Consumption, QlTo send into the efficient heat of burner hearth, h on the basis of one kilogram of calculating fuelfoFor radiation heat transfer area exiting flue gas enthalpy
Value.
According to high-temperature flue gas in the equation of heat balance of radiation heat transfer area heat release, it just can be calculated by successive approximation method and obtain spoke
Penetrate the temperature and enthalpy of heat transfer zone exiting flue gas.
Radiation and convection area exports the calculating of (furnace outlet) flue-gas temperature：
Radiant heat flux by radiation heat transfer area outlet is QI, therefore enter the total hot-fluid in radiation and convection area and be：
Qri=Yghfo+QI
The Radiant exothermicity of flue gas and tweer is：
Qrw=αrArwx1Δθ
Radiant exothermicity between flue gas and radiation and convection area outlet is：
QII=αrAIIx2Δθ
The quantity of heat convection of flue gas and tweer is：
Qc=αcAwΔθ
In the formula of the above three, average heat transfer temperature and pressure Δ θ is represented by：
Always heat exchange amount is：
Qr=Qrw+QII+Qc
Therefore the hot-fluid of furnace outlet is：
Qro=Qri-Qr
Exiting flue gas enthalpy is accordingly：
Furnace outlet gas temperature θ is determined by the corresponding relation of flue-gas temperature and enthalpyroAfterwards, you can try to achieve burner hearth heat absorption hundred as the following formula
Divide ratio and flue gas specific heat：
Burner hearth heat absorption percentage be：
Flue gas specific heat is calculated as follows：
Wherein：hfoFor radiation heat transfer area exiting flue gas enthalpy, αrFor radiation and convection area flue gas and the radiation heat transfer coefficient of furnace wall,
Δ θ is average heat transfer temperature and pressure, θfFor radiation and convection area flame temperature, θroFor flue gas temperature of hearth outlet, θwFor radiation and convection
Area's internal protecting wall temperature, x1For ascent of the flue gas to furnace wall, radiation and convection area furnace wall heat exchange area Arw=2 (W+D) Lr, wherein Lr
For radiation and convection section length, x2For ascent of the flue gas to radiation and convection area outlet, radiation and convection area outlet heat exchange area
AII=AI, αcFor convection transfer rate, AwFor heat convection area, Q is the total amount of heat for entering burner hearth, θadFor adiabatic combustion temperature
Degree.
2) boiler heating surface heat exchange is calculated：During to boiler startup feed-tank, feedwater piping, economizer, water-cooling wall,
Intraductal working medium side is carried out with managing outer flue gas side flowing heat-transfer character in the heating surfaces such as pendant superheater, convection superheater, reheater
On the basis of analysis simplifies, using the distributed parameter model that thermal parameter changes with position coordinates is considered, according to conservation of mass side
Work in journey, momentum conservation equation, energy conservation equation, metal accumulation of heat equation and some supplement establishing equations description start-up courses
Matter temperature, pressure, enthalpy, the mathematical modeling and method for solving of heating surface metal temperature and smoke temperature change rule.
When deriving intraductal working medium with HEAT TRANSFER LAW, make following basic assumption：
1st, assume that parallel transistor heating power waterpower is uniform, the heated of all parallel connection tube banks is represented with a heat pipe and is flowed
Situation；
2nd, the interior outside of wall peripherally equably neither endothermic nor exothermic；
3rd, it is very thin in view of metal pipe-wall, therefore do not consider the radial direction thermal resistance of metallic walls (i.e. without temperature between the inside and outside layer of wall
Difference), and be infinity along the thermal resistance of metal axial；
4th, medium and metallic walls are only exchanged heat in radial direction, without considering axially heat exchange；
5th, Temperature of Working and VELOCITY DISTRIBUTION are uniform in same section, and medium only flows vertically in pipe, nothing
Internal circulation.
Obtained based on assumed above：
Quality continuity equation：
In formula：M-working medium flow, kg/s；
L-flow direction coordinate, m；
F-conduit cross-sectional area, m2；
ρ-working medium density, kg/m3；
T-time, s.
Energy conservation equation：
In formula：q2- the unit interval, unit length tube wall was to refrigerant heat transfer amount, W/m；
H-working medium enthalpy, J/ ㎏；
mwWorking medium quality, m in-unit pipe rangew=ρ F, kg/m；
Utilize dh=cwD θ, energy conservation equation also has a kind of form：
In formula：cw- working medium specific heat capacity, J/ (kg K)；
θ-Temperature of Working, DEG C.
Momentum conservation equation：
In formula：U-refrigerant flow rate, m/s；
P-power pressure, Pa；
β-pipe inclination angle, rad；
fpThe pipe range friction pressure drop of-unit, Pa.
It is also contemplated that the thermal balance of unit length metal pipe-wall can obtain metal accumulation of heat equation in calculating process：
In formula：mM- unit pipe range metal quality, kg/m；
cM- metal specific heat holds, J/ (kg K)；
θM- metal temperature, DEG C；
q1- unit interval flue gas is to the heat output of unit length metal pipe-wall, W/m；
q2- the unit interval, unit length metal pipe-wall was to the heat output of working medium, W/m.
q1、q2It can be determined respectively according to fume side and working medium side convection heat transfer' heat-transfer by convection equation：
q1=αGF1(θG-θM)
q2=α F2(θM-θ)
In formula：αG- flue gas is to the metal pipe-wall coefficient of heat transfer, W/ (m2K)；
α-working medium convection transfer rate, W/ (m2K)；
F1- unit tube long metal pipe wall external surface area, m2；
F2- unit tube long metal pipe wall internal surface area, m2；
θG- flue-gas temperature, DEG C.
To the part tube wall metal temperature such as feed-tank, feedwater piping, economizer, water-cooling wall, due to working medium in these parts
It is very big to the coefficient of heat transfer of metal inner surface, it is believed that metal temperature is identical with Temperature of Working.And to portions such as superheater, reheaters
Part metal temperature, then must take into consideration the difference of Temperature of Working and metal temperature, and by solving the metallic walls of consideration metal accumulation of heat
The differential equation that temperature is followed obtains the heating surface metal temperature of start-up course not in the same time.To boiler Gas Parameters, root everywhere
Calculate the parameters such as flue gas flow, temperature, the specific heat capacity of the moment furnace outlet according to layer combustion rate during current calculate, and the moment cigarette
The energy conservation equation that Temperature Distribution of the gas at the parts such as superheater, reheater and economizer is met by flue gas is solved, cigarette
Throughput, specific heat capacity then think identical with furnace outlet.
Referring to Fig. 1, change mathematical modeling setting up start-up course working medium side with fume side thermal parameter and correctly asked
On the basis of solution, the design feature for the activation system being equipped with according to super critical boiler and the operation characteristic of Steam Turbine Bypass System, profit
With above-mentioned computation model and solution, along with to the mathematical description of some other phenomenon and solution in start-up course, exploitation can
Simulate boiler cold-state, warm state, the computer program of hot starting, hot start process.
The program is write using formula translation, using modular construction, mainly comprising combustion module, input module, several
What computing module, fluid interchange calculate primary module, burning computing module, Water flow-path computing module, water-cooling wall computing module, first
Cross, reheater computing module and the second mistake, reheater computing module etc..In some modules, also data important to some
There is provided self-checking function, once the input value or calculated value of these data exceed the allowed band of program, then shows mistake letter
Breath.Data volume is larger in program calculated result file, is unfavorable for destination file and draws and program debugging, storage has been also set up for this
A certain or a few kind of parameter result of calculation and the data file for starting the time, such as set up steam-water separator water storage pressure tank and open
Dynamic time, excessively reheater out temperature and startup time, main steam temperature, pressure and data file of startup time etc..
Corresponding calculation procedure is repeated, after boiler is negative enters DC state, start-up process simulation terminates, and returns to main journey
Sequence.
1. combustion module：The task of combustion module is the furnace outlet flue gas temperature for calculating the hearth combustion under different combustion rates
Degree, exhaust gas volumn and flue gas specific heat and burner hearth heat absorption percentage, numerical value and beginning and ending time together with the constant combustion rate of input are constituted
The burning data input file that subprogram burning computing module is called.
2. input module：The task of input module is to read in data file, and the data file includes boiler general structure
And the detailed construction size of each part, start initial time boiler working medium, the distribution of flue gas thermal parameter and start-up course one everywhere
A little setting values.
3. geometry computing module：Geometry computing module enters according to data in data file to each modular construction size of boiler
Row calculates to obtain calculating geometric parameter required during the heat transfer of these part mobiles.These geometric parameters mainly include each part
It is each to calculate the corresponding pipe inner and outer surfaces product of grid, volume and metal quality etc..
4. fluid interchange calculates primary module：The task that fluid interchange calculates primary module be to it is different in start-up course when layer pot
Enthalpy drop of the steam in high pressure cylinder is calculated after stove activation system all parts flowing heat transfer situation and steam turbine red switch.
5. burn computing module：Computing module burn it is determined that after new time step, first according to steam-water separator
The method of operation (temperature control or water level control) is calculated working medium flow in water-cooling wall import working medium flow and economizer,
Burner hearth heat absorption percentage, flue gas flow, flue gas temperature of hearth outlet and specific heat when then calculating current corresponding to layer combustion rate
Hold, the ratio of burner hearth caloric receptivity when layer combustion rate lower hearth caloric receptivity is with 100% combustion rate when finally calculating current.
6. Water flow-path computing module：Water flow-path computing module calculates feed-tank to boiler component flowing heat transfer between economizer,
According to the principle of mass conservation, layer water-cooling wall entrance feedwater flow Y during current calculatingfwFor：
Yfw=Ycy-Yxh+YBP+Yp(1)+Yp(2)+Yp(3)
In formula：Ycy--- deaerator storage tank rate of discharge, kg/s；
Yxh--- the layer hydrophobic recirculating mass of steam-water separator, kg/s during current calculating；
YBP--- layer high pressure bypass valve injection flow rate during a upper calculating, determined in mistake, reheater computing module 1, kg/s；
YP(1)、YP(2)、YP(3) --- layer superheater and each injection point injection flow rate of reheater, kg/s during a upper calculating.
7. water-cooling wall computing module：Water-cooling wall computing module mainly calculates water-cooling wall working medium enthalpy, pressure distribution and carbonated drink point
From the hydrophobic enthalpy of device.
8. first crosses, reheater computing module 1：The module mainly calculates no steam and flows into superheater by steam-water separator
Superheater system, reheater system flue gas, Working fluid flow heat transfer and metal pipe-wall Temperature Distribution during system.
9. second crosses, reheater computing module 2：The module calculate have steam by steam-water separator flow into superheater system when
Superheater system, reheater systematic working medium, flow of flue gas heat transfer, metal pipe-wall Temperature Distribution and from time of ignition to calculate when layer
Medium-loss, thermal loss.If turbine inlet parameter is reached after red switch requirement, steam is also calculated in high pressure cylinder or intermediate pressure cylinder
In enthalpy drop.
The present invention is described in further detail with reference to embodiment：
Using certain 600MW supercritical units cold start by ignition of the boiler to steam turbine red switch this period as example, to this
One start-up course is calculated, and is compared the calculated value and measured value of boiler important parameter in start-up course, is as a result shown the journey
Sequence can be good at simulating unit start-up course, available for actual engineering design.
Implementation steps are as follows：
1) it is in order to simplify calculating, ceiling and cladding heating surface is equivalent into two superheaters, it was connected on by flue gas flow
In hot device system.The vertical tube wall of water-cooling wall, preceding screen superheater and Late reworking also press flue gas flow arranged in series.So, cigarette
Flow of air order just successively to Spiral Coil Waterwall, vertical tube plates water-cooling wall, preceding screen superheater, Late reworking, high temperature again
Hot device, finishing superheater, steam, low-temperature reheater, wall enclosed superheater and economizer carry out convection current and radiant heat transfer.
2) consider that the unit activation system is arranged, calculation procedure is divided oxygen-eliminating device, feedwater piping, province by working medium flow altogether
Coal device, water-cooling wall, steam-water separator, air suspended type flash vessel, steam, wall enclosed superheater, preceding screen superheater, rear screen overheat
13 calculating units such as device, finishing superheater, low-temperature reheater and high temperature reheater, and each part is averagely drawn by length
It is divided into the calculating grid of corresponding number.
3) intraductal working medium convection transfer rate and pipe when input all parts tube construction size, minimum direct current load operation
Outer flue gas convection transfer rate, radiation heat transfer coefficient, time of ignition all parts metal temperature distribution and at full capacity when main steam
Flow, temperature, pressure, reheated steam flow, temperature, pressure, superheater system pressure drop, input data also include deaerator storage tank
The quality of water when filling water, time of ignition deaerator storage tank outlet feedwater enthalpy and deaerator storage tank metal quality etc..
4) mathematical modeling that solution start-up course working medium side, fume side and the metal accumulation of heat set up according to program are followed,
Calculate start during each moment working medium side, fume side thermodynamic state and parameter and metal temperature distribution and startup during work
Matter and thermal loss, and result of calculation is analyzed.
Result of calculation is analyzed：
Fig. 2 is that boiler cold-state start-up course combustion rate is changed over time in case study on implementation of the present invention, combustion rate anaplasia at any time
The functional relation of change is used as calculating input condition.Start-up course high pressure turbine by valve opening change such as curve 2 in Fig. 3, makees during calculating
For input condition by the curve matching into functional relation input related subprogram of the valve opening to the time.
The start-up course main steam boosting curve that curve 1 is calculated by program in Fig. 3.As can be seen that the master that program is calculated
Raise steam curve and the actual main steam boosting curve of start-up course closely, show with the actual combustion rate of start-up course
And high pressure turbine by valve opening changes over time relation as input condition, program being capable of correct simulation start-up course main steam pressure
The change of power.What is used in program calculates main steam pressure according to combustion rate, high pressure turbine by valve opening and some other parameters
Model is correct.Accordingly, optimal start up curve just can be provided for power plant user using the program.
Fig. 4 is compared for the calculated value of start-up course steam-water separator water storage pressure tank with measured value.It can be seen that
In the past, working medium is not yet vaporized 18.5min in water-cooling wall, and steam is had no this moment and flows into superheater system.Water-cooling wall goes out during 18.5min
Mouth working medium is steam-water twin phases mixture, and relevant pressure is 13.7bar, after steam-water separator is separated, wherein saturated steam flowing
Enter superheater system, steam-water separator water storage pressure tank rises to 20.6bar by 13.7bar, the increase put into fuel quantity, water
There is carbonated drink expansion in cold wall, causes a large amount of water vapours to enter steam-water separator, causes mutation of water level, and the vapour in 49.3min
Separator water storage pressure tank is quickly ramped up to 44.1bar by 20.6bar.The bright steam-water separator calculation of pressure model of the chart is accurate
It is really reliable.
What Fig. 5 was represented be respectively with program calculate and power plant it is actual measurement acquisition start-up course pendant superheater into and out of
Mouth vapor (steam) temperature, curve 1 is respectively start-up course pendant superheater import and export steam calculated value with curve 2.They and measured value
Basically identical, it is correct to show the intraductal working medium of program use and manage outer flue gas unsteady state flow to move Calculation of Heat Transfer model.
Curve is that start-up course is finishing superheater outlet steam temperature calculated value in Fig. 6, it can be seen that it and measured value
It is basically identical.Due to being only collected into the measured value of the indivedual each parameters of moment boiler of start-up course, it is assumed here that some time sections
Water spray impose a condition, it is ensured that inlet steam temperature measured value and calculated value are equal at the collection measured value moment.But superheater
It is a transient that Working fluid flow heat transfer and the outer flow of flue gas of pipe, which are conducted heat, in system, and this just necessarily brings some to miss to calculating
Difference.As can be seen that when the time of startup is 49.8min, it is 329.8 DEG C that tube wall temperature calculated value is steamed in finishing superheater outlet, measurement
It is worth for 350.9 DEG C, relative error is up to 6%.
Fig. 7 is the calculated value and measured value of low temperature superheater outlet steam temperature in start-up course, it can be seen that calculated value
Meet preferably with measured value, it is correct to show the intraductal working medium of program use and manage outer flue gas unsteady state flow to move heat transfer model
's.
By comparing result of calculation and actual measured results comprehensively, show the startup of the correct analog DC boiler of program energy
Process.
The boiler startup time is shorter, during payment for initiation is used and started the fewer but too fast startup of heat loss can in header and
Cause excessive thermal stress in steam-water separator uniform thickness wall elements.By means of starting calculation procedure, heavy wall element thermal stress and longevity
Life analysis program just can provide optimal boiler boosting and corresponding combustion rate change curve for operations staff, so as to ensure to set
On the premise of standby safety, with most short time completion start-up course, during farthest saving payment for initiation use and reducing startup
Working medium and thermal loss.
Claims (10)
1. the startup computational methods of a kind of super critical boiler, it is characterised in that comprise the following steps：
1) hearth combustion is calculated：Burner hearth is divided into radiation heat transfer area and two, radiation and convection area part, two parts entered respectively
Row is calculated, and obtains different combustion rate lower hearth exit gas temperatures, burner hearth heat absorption percentage and flue gas specific heat；
2) boiler heating surface heat exchange is calculated：Intraductal working medium side is flowed with managing outer flue gas side in heating surface during to boiler startup
On the basis of heat-transfer character progress analysis simplifies, the distributed parameter model changed using consideration thermal parameter with position coordinates, root
According in mass-conservation equation, momentum conservation equation, energy conservation equation, metal accumulation of heat equation and supplement establishing equation start-up course
Temperature of Working, pressure, enthalpy, the mathematical modeling of heating surface metal temperature and smoke temperature change rule, and solved.
2. a kind of startup computational methods of super critical boiler according to claim 1, it is characterised in that the radiation heat transfer
Area is burner hearth bottom to the region between burner, and its heat transfer type is radiation heat transfer, does not consider that the convection current of flue gas and furnace wall is changed
Heat；The radiation and convection area is more than radiation heat transfer area until the part of furnace outlet, the heat transfer of area's flame and water-cooling wall
Based on radiation heat transfer, while considering heat convection caused by flow of flue gas.
3. a kind of startup computational methods of super critical boiler according to claim 2, it is characterised in that step 1) in spoke
Heat transfer zone is penetrated to be calculated, including：
The Radiant exothermicity of radiation heat transfer area flame and furnace wall is：
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Radiant exothermicity between flame and radiation heat transfer area outlet is：
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High-temperature flue gas is in the equation of heat balance of radiation heat transfer area heat release：
More than in three formulas, CsFor flame and the radiation heat transfer coefficient of furnace wall, εfFor total emissivity, the heat exchange of radiation heat transfer area furnace wall
Area Afw=2 (W+D) Lf+ WD, radiation heat transfer area outlet heat exchange area AI=WD, W are that stove is wide, and D is that stove is deep, LfFor radiation
Heat transfer zone height, x is ascent of the flame to furnace wall, and μ is that flame-gas radiation exchanges ratio, TfWith TwRespectively radiation heat transfer
Area's flame temperature and furnace wall temperature,To consider the errors in radiation heat transfer area after radiation loss, BjTo calculate fuel consumption
Amount, QlTo send into the efficient heat of burner hearth, h on the basis of one kilogram of calculating fuelfoFor radiation heat transfer area exiting flue gas enthalpy；
According to high-temperature flue gas in the equation of heat balance of radiation heat transfer area heat release, it can be calculated by successive approximation method and obtain radiation and change
The temperature and enthalpy of hot-zone exiting flue gas.
4. a kind of startup computational methods of super critical boiler according to claim 3, it is characterised in that step 1) in spoke
Convective region is penetrated to be calculated, including：
It is Q according to the radiant heat flux of radiation heat transfer area outletICalculating the total hot-fluid into radiation and convection area is：
Qri=Yghfo+QI
The Radiant exothermicity of flue gas and tweer is：
Qrw=αrArwx1Δθ
Radiant exothermicity between flue gas and radiation and convection area outlet is：
QII=αrAIIx2Δθ
In the formula of the above three, average heat transfer temperature and pressure Δ θ is expressed as：
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Always heat exchange amount is：
Qr=Qrw+QII+Qc
Therefore the hot-fluid of furnace outlet is：
Qro=Qri-Qr
Exiting flue gas enthalpy is accordingly：
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Furnace outlet gas temperature θ is determined by the corresponding relation of flue-gas temperature and enthalpyroAfterwards, you can try to achieve burner hearth heat absorption percentage as the following formula
With flue gas specific heat：
Burner hearth heat absorption percentage be：
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Flue gas specific heat is：
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Wherein：hfoFor radiation heat transfer area exiting flue gas enthalpy, αrFor radiation and convection area flue gas and the radiation heat transfer coefficient of furnace wall, Δ θ
For average heat transfer temperature and pressure, θfFor radiation and convection area flame temperature, θroFor flue gas temperature of hearth outlet, θwFor in radiation and convection area
Furnace wall temperature, x1For ascent of the flue gas to furnace wall, radiation and convection area furnace wall heat exchange area Arw=2 (W+D) Lr, wherein LrFor spoke
Penetrate convection current section length, x2For ascent of the flue gas to radiation and convection area outlet, radiation and convection area outlet heat exchange area AI=
AII, αcFor convection transfer rate, AwFor heat convection area, Q is the total amount of heat for entering burner hearth, θadFor adiabatic combustion temperature.
5. a kind of startup computational methods of super critical boiler according to claim 1, it is characterised in that step 2) in pushing away
When leading intraductal working medium with HEAT TRANSFER LAW, make following basic assumption：
A) assume that parallel transistor heating power waterpower is uniform, the heated and flowing feelings of all parallel connection tube banks are represented with a heat pipe
Condition；
B) the interior outside of wall peripherally equably neither endothermic nor exothermic；
C) consider that metal pipe-wall is very thin, therefore do not consider the radial direction thermal resistance of metallic walls, and be infinite along the thermal resistance of metal axial
Greatly；
D) medium is only exchanged heat with metallic walls in radial direction, without considering axially heat exchange；
E) Temperature of Working and VELOCITY DISTRIBUTION are uniform in same section, and medium only flows vertically in pipe, no inside
Circulation.
6. the startup computational methods of a kind of super critical boiler according to claim 5, it is characterised in that false based on more than
If quality continuity equation is expressed as：
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In formula：M-working medium flow, kg/s；
L-flow direction coordinate, m；
F-conduit cross-sectional area, m2；
ρ-working medium density, kg/m3；
T-time, s；
Energy conservation equation：
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In formula：q2- the unit interval, unit length tube wall was to refrigerant heat transfer amount, W/m；
H-working medium enthalpy, J/kg；
mwWorking medium quality, m in-unit pipe rangew=ρ F, kg/m；
Due to dh=cwD θ, energy conservation equation can also be expressed as：
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<mi>&theta;</mi>
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In formula：cw- working medium specific heat capacity, J/ (kg K)；
θ-Temperature of Working, DEG C；
Momentum conservation equation：
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In formula：U-refrigerant flow rate, m/s；
P-power pressure, Pa；
β-pipe inclination angle, rad；
fpThe pipe range friction pressure drop of-unit, Pa；
The thermal balance of unit length metal pipe-wall is considered in calculating process, metal accumulation of heat equation is obtained：
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In formula：mM- unit pipe range metal quality, kg/m；
cM- metal specific heat holds, J/ (kg K)；
θM- metal temperature, DEG C；
q1- unit interval flue gas is to the heat output of unit length metal pipe-wall, W/m；
q2- the unit interval, unit length metal pipe-wall was to the heat output of working medium, W/m；
q1、q2Determined respectively according to fume side and working medium side convection heat transfer' heat-transfer by convection equation：
q1=αGF1(θG-θM)
q2=α F2(θM-θ)
In formula：αG- flue gas is to the metal pipe-wall coefficient of heat transfer, W/ (m2K)；
α-working medium convection transfer rate, W/ (m2K)；
F1- unit tube long metal pipe wall external surface area, m2；
F2- unit tube long metal pipe wall internal surface area, m2；
θG- flue-gas temperature, DEG C；
To feed-tank, feedwater piping, economizer, water wall section tube wall metal temperature, due in these parts working medium to metal
The coefficient of heat transfer of inwall is very big, it is believed that metal temperature is identical with Temperature of Working, and to superheater, reheater section Metal Temperature
Degree, then must take into consideration the difference of Temperature of Working and metal temperature, and consider that the tube wall temperature of metal accumulation of heat is followed by solving
The differential equation obtain start-up course heating surface metal temperature not in the same time, to boiler Gas Parameters everywhere, according to current meter
Layer combustion rate calculates the flue gas flow of the moment furnace outlet, temperature, specific heat capacity parameter during calculation, and the moment flue gas is in overheat
The energy conservation equation that Temperature Distribution at device, reheater and economizer part is met by flue gas is solved, flue gas flow, specific heat
Rong Ze thinks identical with furnace outlet.
7. a kind of startup computing system for the super critical boiler for realizing claim 1 methods described, it is characterised in that including：
Combustion module：Flue gas temperature of hearth outlet, exhaust gas volumn and flue gas ratio for calculating the hearth combustion under different combustion rates
Heat and burner hearth heat absorption percentage；
Input module：For reading in data file, the data file includes boiler general structure and the detailed construction of each part
Size, starts the setting value of initial time boiler working medium, the distribution of flue gas thermal parameter and start-up course everywhere；
Geometry computing module：For according to data in data file, modular construction size each to boiler calculated
These part mobiles geometric parameter required when conducting heat；
Fluid interchange calculates primary module：For to it is different in start-up course when layer boiler start-up system all parts flowing heat transfer feelings
Enthalpy drop of the steam in high pressure cylinder is calculated after condition and steam turbine red switch；
Burn computing module：For the method for operation according to steam-water separator in water-cooling wall import working medium flow and economizer
Working medium flow is calculated, and burner hearth heat absorption percentage, flue gas flow, the burner hearth when then calculating current corresponding to layer combustion rate go out
Mouth flue-gas temperature and specific heat capacity, burner hearth absorbs heat when layer combustion rate lower hearth caloric receptivity is with 100% combustion rate when finally calculating current
The ratio of amount；
Flow circulation module：For calculating feed-tank to boiler component flowing heat transfer between economizer, and according to the principle of mass conservation,
Layer water-cooling wall entrance feedwater flow during current calculating；
Water-cooling wall computing module：For calculating water-cooling wall working medium enthalpy, pressure distribution and the hydrophobic enthalpy of steam-water separator；
First crosses, reheater computing module：For calculating overheat when flowing into superheater system by steam-water separator without steam
Device system closes reheater system flue gas, Working fluid flow heat transfer and metal pipe-wall Temperature Distribution；
Second crosses, reheater computing module：For calculate have steam by steam-water separator flow into superheater system when superheater system
System and reheater systematic working medium, flow of flue gas heat transfer, metal pipe-wall Temperature Distribution and the working medium from layer during time of ignition to calculating
Loss, thermal loss.
8. the startup computing system of a kind of super critical boiler according to claim 7, it is characterised in that combustion module is fallen into a trap
Flue gas temperature of hearth outlet, exhaust gas volumn and flue gas specific heat and the burner hearth heat absorption hundred of hearth combustion under obtained different combustion rates
Divide ratio, numerical value and beginning and ending time together with the constant combustion rate of input constitute the burning data input that burning computing module is called
Value.
9. a kind of startup computing system of super critical boiler according to claim 7, it is characterised in that geometry computing module
The geometric parameter of middle calculating each calculates the corresponding pipe inner and outer surfaces product of grid, volume and metallic including each part of boiler
Amount.
10. the startup computing system of a kind of super critical boiler according to claim 7, it is characterised in that Water flow-path is calculated
According to the principle of mass conservation in module, layer water-cooling wall entrance feedwater flow Y during current calculatingfwFor：
Yfw=Ycy-Yxh+YBP+Yp(1)+Yp(2)+Yp(3)
In formula：Ycy--- deaerator storage tank rate of discharge, kg/s；
Yxh--- the layer hydrophobic recirculating mass of steam-water separator, kg/s during current calculating；
YBP--- layer high pressure bypass valve injection flow rate during a upper calculating, determined in the first mistake, reheater computing module, kg/s；
YP(1)、YP(2)、YP(3) --- layer superheater and each injection point injection flow rate of reheater, kg/s during a upper calculating.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108679640A (en) * | 2018-03-22 | 2018-10-19 | 西安交通大学 | The fuel control method that Boiler Metallic accumulation of heat changes during consideration thermal power plant peak regulation |
| CN109977560A (en) * | 2019-03-29 | 2019-07-05 | 江苏方天电力技术有限公司 | A kind of waste heat boiler dynamic operational behaviour modeling method |
| CN110274627A (en) * | 2019-06-25 | 2019-09-24 | 西安交通大学 | The measurement method of interior high temperature and pressure working medium flow distribution is restrained in parallel connection |
| CN112182843A (en) * | 2020-09-02 | 2021-01-05 | 项家从 | Virtual detection method for furnace combustion temperature |
| CN112446134A (en) * | 2020-10-23 | 2021-03-05 | 中南大学 | Method for calculating heat loss of furnace body region in electric arc furnace steelmaking process |
| CN112989719A (en) * | 2021-03-03 | 2021-06-18 | 东南大学 | Dynamic characteristic modeling method for gas boiler unit |
| CN113449251A (en) * | 2021-06-24 | 2021-09-28 | 东北电力大学 | Method for calculating flue gas temperature in heat transfer process of forward-flow arrangement supercritical economizer |
| CN114398749A (en) * | 2021-11-30 | 2022-04-26 | 西安交通大学 | Safety calculation method for heating surface of supercritical (super-supercritical) boiler in power-off accident |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102734783A (en) * | 2012-06-12 | 2012-10-17 | 广东电网公司电力科学研究院 | Method for calibrating monitoring data parameters of heat-absorbing surfaces at each level of supercritical boiler of power station |
| CN103699790A (en) * | 2013-12-17 | 2014-04-02 | 上海交通大学 | Method for detecting average temperature of hearth outlet smoke of coal-fired power plant in real time |
| US20140262257A1 (en) * | 2013-03-14 | 2014-09-18 | Babcock & Wilcox Power Generation Group, Inc. | Small supercritical once-thru steam generator |
| CN104763997A (en) * | 2015-03-09 | 2015-07-08 | 章礼道 | Parameter optimization ultra-supercritical secondary reheating power station boiler |
| CN106021916A (en) * | 2016-05-18 | 2016-10-12 | 厦门大学 | Calculation method suitable for NOx emission of ultra-supercritical boiler |
-
2017
- 2017-06-08 CN CN201710428811.5A patent/CN107292006B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102734783A (en) * | 2012-06-12 | 2012-10-17 | 广东电网公司电力科学研究院 | Method for calibrating monitoring data parameters of heat-absorbing surfaces at each level of supercritical boiler of power station |
| US20140262257A1 (en) * | 2013-03-14 | 2014-09-18 | Babcock & Wilcox Power Generation Group, Inc. | Small supercritical once-thru steam generator |
| CN103699790A (en) * | 2013-12-17 | 2014-04-02 | 上海交通大学 | Method for detecting average temperature of hearth outlet smoke of coal-fired power plant in real time |
| CN104763997A (en) * | 2015-03-09 | 2015-07-08 | 章礼道 | Parameter optimization ultra-supercritical secondary reheating power station boiler |
| CN106021916A (en) * | 2016-05-18 | 2016-10-12 | 厦门大学 | Calculation method suitable for NOx emission of ultra-supercritical boiler |
Non-Patent Citations (2)
| Title |
|---|
| 杨冬 等: ""600MW变压运行超临界参数锅炉启动过程模拟计算"", 《动力工程》 * |
| 杨冬 等: ""直流锅炉启动过程模拟计算程序OTBSP的开发"", 《西安交通大学学报》 * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108679640A (en) * | 2018-03-22 | 2018-10-19 | 西安交通大学 | The fuel control method that Boiler Metallic accumulation of heat changes during consideration thermal power plant peak regulation |
| CN108679640B (en) * | 2018-03-22 | 2019-06-14 | 西安交通大学 | The fuel control method that Boiler Metallic accumulation of heat changes during consideration thermal power plant's peak regulation |
| CN109977560A (en) * | 2019-03-29 | 2019-07-05 | 江苏方天电力技术有限公司 | A kind of waste heat boiler dynamic operational behaviour modeling method |
| CN110274627A (en) * | 2019-06-25 | 2019-09-24 | 西安交通大学 | The measurement method of interior high temperature and pressure working medium flow distribution is restrained in parallel connection |
| CN110274627B (en) * | 2019-06-25 | 2020-06-19 | 西安交通大学 | Measuring method for high-temperature and high-pressure working medium flow distribution in parallel tube bundle |
| CN112182843A (en) * | 2020-09-02 | 2021-01-05 | 项家从 | Virtual detection method for furnace combustion temperature |
| CN112446134A (en) * | 2020-10-23 | 2021-03-05 | 中南大学 | Method for calculating heat loss of furnace body region in electric arc furnace steelmaking process |
| CN112989719A (en) * | 2021-03-03 | 2021-06-18 | 东南大学 | Dynamic characteristic modeling method for gas boiler unit |
| CN112989719B (en) * | 2021-03-03 | 2023-12-22 | 东南大学 | Dynamic characteristic modeling method for gas boiler unit |
| CN113449251A (en) * | 2021-06-24 | 2021-09-28 | 东北电力大学 | Method for calculating flue gas temperature in heat transfer process of forward-flow arrangement supercritical economizer |
| CN114398749A (en) * | 2021-11-30 | 2022-04-26 | 西安交通大学 | Safety calculation method for heating surface of supercritical (super-supercritical) boiler in power-off accident |
| CN114398749B (en) * | 2021-11-30 | 2024-03-29 | 西安交通大学 | Safety calculation method for heating surface of supercritical (super) boiler under power failure accident |
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