CN112933942A - Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology - Google Patents

Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology Download PDF

Info

Publication number
CN112933942A
CN112933942A CN202110124868.2A CN202110124868A CN112933942A CN 112933942 A CN112933942 A CN 112933942A CN 202110124868 A CN202110124868 A CN 202110124868A CN 112933942 A CN112933942 A CN 112933942A
Authority
CN
China
Prior art keywords
sncr
fuel
heat
flue gas
boiler
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110124868.2A
Other languages
Chinese (zh)
Inventor
杨希刚
古世军
陈国庆
黄林滨
李昌松
戴维葆
杜庆敏
张晖
刘柱
金保昇
张勇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guodian Nanning Power Generation Co ltd
State Energy Group Guangxi Electric Power Co ltd
Southeast University
CHN Energy Group Science and Technology Research Institute Co Ltd
Guodian Nanjing Electric Power Test Research Co Ltd
Original Assignee
Guodian Nanning Power Generation Co ltd
State Energy Group Guangxi Electric Power Co ltd
Southeast University
CHN Energy Group Science and Technology Research Institute Co Ltd
Guodian Nanjing Electric Power Test Research Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guodian Nanning Power Generation Co ltd, State Energy Group Guangxi Electric Power Co ltd, Southeast University, CHN Energy Group Science and Technology Research Institute Co Ltd, Guodian Nanjing Electric Power Test Research Co Ltd filed Critical Guodian Nanning Power Generation Co ltd
Priority to CN202110124868.2A priority Critical patent/CN112933942A/en
Publication of CN112933942A publication Critical patent/CN112933942A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/77—Liquid phase processes
    • B01D53/79—Injecting reactants
    • 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
    • B01D53/54—Nitrogen compounds
    • B01D53/56—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J7/00—Arrangement of devices for supplying chemicals to fire
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2067—Urea
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chimneys And Flues (AREA)

Abstract

The invention discloses a coal-fired power plant boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology, wherein the boiler fuel efficiency is obtained by respectively calculating the heat loss rate of exhaust smoke, the heat loss rate of incomplete combustion of gas, the heat loss rate of incomplete combustion of solid, the heat dissipation loss rate of a boiler, the physical sensible heat loss rate of ash, the heat loss rate of SNCR reaction, other heat loss rates of the boiler, and the percentage of external heat and the lower calorific value of fuel after the SNCR is put into operation; the SNCR reaction heat loss rate comprises urea melting phase change absorption heat, liquid water in urea solution heating gasification absorption heat and heat loss rate caused by release heat of urea chemical reaction. The invention provides a method for accurately and uniformly distributing urea solution sprayed into a hearth to unit mass fuel by calculating the difference value of the moisture content of flue gas at the outlet of an air preheater of an SNCR boiler during operation and shutdown for the first time, and solves the problem that the quality of the fuel entering the hearth and the urea solution entering the hearth are difficult to accurately measure.

Description

Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology
Technical Field
The invention designs a method for calculating the boiler fuel efficiency of a coal-fired generator set by adopting an SNCR (selective non-catalytic reduction) denitration technology.
Background
In recent years, with the continuous improvement of environmental protection requirements, SNCR flue gas denitration technology is additionally arranged for a plurality of domestic coal-fired power generating units to control the emission of nitrogen oxides. The SNCR denitration technology is characterized in that 5-10% of urea solution is sprayed into a hearth to be pyrolyzed to generate ammonia gas to reduce NO. The influence on the fuel efficiency of the boiler is very obvious due to the large amount of water sprayed into the boiler, and the experimental measurement and calculation of the fuel thermal efficiency of the boiler after the SNCR denitration technology is adopted have important value for evaluating the SNCR operation cost.
At present, the method for calculating the fuel efficiency of the boiler of the domestic large-scale coal-fired power plant boiler is in accordance with GB/T10184-2015, and the standard specifies a method for calculating the boiler efficiency of the boiler of the coal-fired power plant boiler and a method for calculating the boiler efficiency after a calcium-based desulfurizer is sprayed into the boiler, but the method is not suitable for calculating the fuel efficiency of the boiler adopting an SNCR (selective non-catalytic reduction) denitration technology. The main reasons are as follows: 1. the influence of the sprayed water amount of the SNCR on the heat loss of the steam in the boiler exhaust heat loss is not considered; 2. heat loss of SNCR denitration reaction is not considered; 3. the influence of SNCR denitration reaction on the heat loss of the dry flue gas is not considered. If the standard method is adopted to calculate the fuel efficiency of the coal-fired power plant boiler adopting the SNCR denitration technology, the influence of the 3 large aspects is easily ignored, the calculated fuel efficiency of the boiler is lower by 1-2%, and the error is extremely large.
The measurement of the urea injected by the SNCR denitration technology is not accurate, the coal amount of coal as fired of the coal-fired power station boiler cannot be accurately calculated, and the reaction process of the urea solution injected into a hearth is complex, so that the fuel efficiency of the coal-fired power station boiler is difficult to obtain by accurate measurement and calculation after the SNCR denitration technology is adopted, and an accurate method is not available at present.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provides a method for calculating the fuel efficiency of a boiler of a post-combustion coal electric station of an SNCR (selective non-catalytic reduction) denitration system.
In order to achieve the above object, the present invention disclosesThe invention discloses a boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology, and the boiler fuel efficiency eta isSNCRBy respectively calculating the heat loss rate q of exhaust smoke after the SNCR is put into operation2,SNCRGas incomplete combustion heat loss rate q3,SNCRHeat loss rate q of incomplete combustion of solid4,SNCRBoiler heat dissipation loss rate q5,SNCRAsh physical sensible heat loss rate q6,SNCRSNCR reaction Heat loss Rate q7,SNCROther heat loss rate q of boilerqt,SNCRPercent of external heat to lower calorific value of fuel qw1,SNCRObtaining; the SNCR reaction heat loss rate q7,SNCRThe method comprises the steps of urea melting phase change heat absorption, liquid water heating gasification heat absorption in urea solution, and heat loss rate caused by heat release of urea chemical reaction.
Wherein the content of the first and second substances,
ηSNCR＝100-q2,SNCR-q3,SNCR-q4,SNCR-q5,SNCR-q6,SNCR-q7,SNCR-qqt,SNCR+qw1,SNCR，％。
according to the invention, the calculation of the heat loss rate of the SNCR denitration reaction is increased, the influence of the SNCR reaction on the fuel efficiency of the boiler is fully considered, and meanwhile, the total package reaction is adopted to calculate the heat loss of the SNCR denitration reaction, so that the calculation is more accurate.
Wherein the heat loss rate q of exhaust gas2,SNCRThe heat loss rate caused by dry flue gas generated by fuel combustion and the heat loss rate caused by heat carried out of the system by water vapor in the flue gas are included; the dry flue gas generated by fuel combustion also comprises dry flue gas generated by SNCR reaction corresponding to unit mass of fuel, and the water vapor in the flue gas also comprises moisture brought by urea solution and moisture generated by SNCR reaction.
In the invention, in the calculation of the heat loss rate of the exhaust smoke, the heat loss caused by the dry smoke and the heat taken away by the water vapor contained in the smoke are considered, and the influence of the urea solution sprayed into the furnace by the SNCR system and the reaction thereof on the volume of the dry smoke and the influence of the water vapor amount are also considered, so that the calculation is more accurate.
In the specific calculation, the exhaust heat loss rate q2,SNCR，％＝Q2,SNCR/Qnet,SNCR×100；Q2,SNCRFor lost heat, Q, caused by flue gas generated by combustion of unit mass of fuel after SNCR commissioningnet,SNCRThe lower calorific value of the fuel entering the furnace; volume of dry flue gas generated by SNCR reaction corresponding to unit mass of fuel
Figure BDA0002923265310000021
By calculating the mass of urea solution sprayed into the furnace by the SNCR system corresponding to the unit mass of fuel
Figure BDA0002923265310000022
Obtaining:
Figure BDA0002923265310000023
in the calculation process of the influence of the SNCR reaction on the volume of the dry flue gas, the urea solution sprayed into the furnace by the SNCR system is uniformly distributed on the fuel with unit mass, and a calculation model is established, so that the method is more accurate and convenient.
Wherein the lost heat Q caused by flue gas generated by combustion of unit mass of fuel after SNCR operation2,SNCRInvolving the heat Q taken away from the system by the dry flue gas2,gyAnd the heat taken away by the water vapor contained in the flue gas
Figure BDA0002923265310000024
Figure BDA0002923265310000025
Q2，gy＝Vgy，SNcRCp，gy，SNCR(tgy，ky，o，SNCR-tjz)；
In the formula (I), the compound is shown in the specification,
Figure BDA0002923265310000031
volume of air, m, required for the combustion theory of fuel per unit mass3/kg；
Figure BDA0002923265310000032
Generated for SNCR reaction per unit mass of fuelVolume of flue gas, m3Per kg; alpha is the excess air factor at the outlet of the air preheater after the SNCR was put into service.
The heat taken away by the vapor contained in the flue gas after the SNCR system is put into operation
Figure BDA0002923265310000033
Calculated by the following formula:
Figure BDA0002923265310000034
in the formula (I), the compound is shown in the specification,
Figure BDA0002923265310000035
volume of water vapor in flue gas at outlet of air preheater generated by combustion of unit mass of fuel after operation of SNCR system3/kg；tjzTest reference temperature, deg.C; t is tgy，ky，o，SNCRThe outlet flue gas temperature of an air preheater at the rear of the operation of the SNCR system is DEG C;
Figure BDA0002923265310000036
is water vapor from tjzTo tgy，ky，o，SNCRConstant pressure specific heat capacity, kJ/(m)3.K)；
Wherein the volume of water vapor in flue gas at the outlet of the air preheater generated by combustion of fuel per unit mass after operation of the SNCR system
Figure BDA0002923265310000037
The method also comprises the water brought in by the urea solution after the SNCR system is put into operation and the water generated by the SNCR reaction.
When the volume of the water vapor in the flue gas at the outlet of the air preheater is calculated, the influence brought by the water in the urea solution and the water generated by the reaction of the water in the urea solution after the SNCR system is put into operation is fully considered.
In the concrete calculation, the volume of the water vapor in the flue gas at the outlet of the air preheater generated by burning the fuel with unit mass after the SNCR system is put into operation
Figure BDA0002923265310000038
Calculated by the following formula:
Figure BDA0002923265310000039
in the formula, HarIs the received base hydrogen content of the fuel,%; marIs the received base moisture content,%, of the fuel;
Figure BDA00029232653100000310
volume of air, m, required for the combustion theory of fuel per unit mass3/kg；hkq，abIs the absolute moisture content of air, kg/kg; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
The invention reacts to the SNCR heat loss rate q7,SNCRBy calculating the mass of urea solution sprayed into the furnace by the SNCR system corresponding to the unit mass of fuel
Figure BDA00029232653100000311
Obtaining:
Figure BDA00029232653100000312
in the formula, a, the ammonia nitrogen molar ratio of urea and NO in flue gas is sprayed; b-denitration efficiency of SNCR reaction system,%; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
The invention establishes a calculation method of the SNCR denitration reaction heat loss term by introducing two parameters of ammonia nitrogen molar ratio and denitration efficiency.
The invention has the heat loss rate q of incomplete combustion of gas3,SNCRThe calculation of the volume of the discharged smoke also comprises dry smoke generated by SNCR reaction corresponding to unit mass of fuel
Figure BDA0002923265310000041
Dry flue gas generated by SNCR reaction corresponding to the unit mass of fuel
Figure BDA0002923265310000042
By calculating the mass of urea solution sprayed into the furnace by the SNCR system corresponding to the unit mass of fuel
Figure BDA0002923265310000043
Obtaining:
Figure BDA0002923265310000044
in the invention, the influence of the SNCR system on the volume of dry flue gas is also fully considered in the calculation of the incomplete combustion heat loss rate of gas.
Percentage q of external heat to low calorific value of fuel in the present inventionw1,SNCRThe external heat also comprises physical sensible heat Q brought by the urea solutionf,SNCR。
The invention carries out physical sensible heat Q on the urea solutionf,SNCRCalculated by the following formula:
Figure BDA0002923265310000045
Figure BDA0002923265310000046
Figure BDA0002923265310000047
in the formula (I), the compound is shown in the specification,
Figure BDA0002923265310000048
the physical sensible heat of urea and water is kJ/kg;
Figure BDA0002923265310000049
Figure BDA00029232653100000410
the specific heat capacities of urea and water are kJ/(kg. K);
Figure BDA00029232653100000411
the temperatures of urea and water entering the system boundary, respectively, are in deg.C; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
The invention also fully considers the influence of the SNCR system in the calculation of the percentage of the external heat and the lower calorific value of the fuel.
The mass of the urea solution sprayed into the furnace by the SNCR system corresponding to the unit mass of the fuel
Figure BDA00029232653100000412
Calculated by the following method:
Figure BDA0002923265310000051
in the formula (I), the compound is shown in the specification,
Figure BDA0002923265310000052
the difference value of the corresponding moisture content of the dry flue gas at the outlet of the air preheater before the operation of the SNCR system is kg/m3；Vgy，no-SNCRVolume of dry flue gas at outlet of air preheater before operation of SNCR system, m3Per kg; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
Compared with the prior art, the invention has the following advantages:
1. the method for accurately and uniformly distributing the urea solution sprayed into the hearth to the fuel with unit mass by calculating the difference value of the moisture contents of the flue gas at the outlet of the air preheater of the SNCR boiler during operation and shutdown is put forward for the first time, and the problem that the quality of the fuel entering the hearth and the urea solution entering the hearth are difficult to accurately measure is effectively solved.
2. A new heat loss item of the boiler, namely SNCR denitration reaction heat loss is introduced, the total package reaction is adopted to calculate the SNCR denitration reaction heat loss on the basis of the denitration elementary reaction, and a calculation method of the SNCR denitration reaction heat loss item is established by introducing two parameters of ammonia nitrogen molar ratio and denitration efficiency, so that the calculation of the boiler heat efficiency under the SNCR operation condition is more accurate.
3. The method establishes a flow for calculating the boiler fuel efficiency of the coal-fired power station by adopting the SNCR denitration technology, and provides a theoretical technology for the influence of the SNCR operation on the boiler fuel efficiency.
Drawings
FIG. 1 is a flow of fuel efficiency test and calculation of a coal-fired power plant boiler adopting SNCR denitration technology.
Detailed Description
The present invention will be described in detail with reference to specific examples.
Firstly, establishing a mathematical model
1. Boiler fuel efficiency general expression
Figure BDA0002923265310000053
Formula (II)
The method comprises the following steps: etaSNCRBoiler efficiency after SNCR commissioning,%;
Q2,SNCR-heat loss heat, kJ/kg, caused by flue gas generated by combustion of unit mass of fuel after SNCR is put into operation;
Q3,SNCR-the incomplete combustion of gases produced by the combustion of the fuel per unit mass after the SNCR is put into operation causes a loss of heat, kJ/kg;
Q4,SNCR-heat loss after SNCR, kJ/kg, caused by incompletely burned solids after combustion per unit mass of fuel;
Q5,SNCR-boiler heat dissipation heat per unit mass of fuel after SNCR is put into operation, kJ/kg;
Q6,SNCRafter the SNCR is put into operation, the physical heat loss of ash corresponding to the fuel of unit mass is kJ/kg;
Q7,SNCR-kJ/kg relative to the heat loss per unit mass of fuel caused by the SNCR reaction;
Qqt,SNCRq removal of unit mass fuel after SNCR commissioning2,SNCR～Q7,SNCROther boilers lose heat, kJ/kg;
Qnet,ar-lower calorific value of the fuel (receiving basis) fed to the furnace, kJ/kg;
Qwl,SNCRall other input heat, kJ/kg, except the calorific value of the fuel fed into the furnace.
By conversion, equation (1) can be expressed as:
ηSNCR＝100-q2,SNCR-q3,SNCR-q4,SNCR-q5,SNCR-q6,SNCR-q7,SNCR-qqt,SNCR+qwl,SNCR (2)
formula (II)
The method comprises the following steps: etaSNCRBoiler efficiency after SNCR commissioning,%;
q2,SNCR-heat loss from exhaust gas after SNCR is put into operation,%;
q3,SNCRheat loss,%, from incomplete combustion of gases after SNCR operation;
q4,SNCRheat loss,%, from incomplete combustion of solids after SNCR put into service;
q5,SNCRboiler heat dissipation loss after SNCR commissioning,%;
q6,SNCRphysical sensible heat loss of ash after SNCR put into operation,%;
q7,SNCRSNCR heat loss after SNCR commissioning,%;
qqt,SNCR-commissioning SNCR post-divide-by-q2,SNCR～q7,SNCROther heat losses of other boilers,%;
qwl,SNCRpercent of external heat to low fuel heating value.
2. Lost heat Q caused by flue gas generated by combustion of unit mass of fuel after SNCR (selective non-catalytic reduction) operation2,SNCR
The heat lost by flue gas generated by burning unit mass of fuel after the SNCR is put into operation comprises two parts: firstly, the lost heat that the dry flue gas that fuel burning produced arouses, secondly, the heat loss that the steam in the flue gas carried the heat that goes out the system arouses can be expressed as:
Q2,SNCR＝Q2,gy+Q2,H2O (3)
in the formula:Q2,gy-the amount of heat, kJ/kg, taken from the system by the dry flue gas;
Figure BDA0002923265310000077
-the heat, kJ/kg, carried away by the water vapour contained in the flue gas.
2.1 Heat Q taken from the System by Dry flue gas2,gy
The quantity of heat taken away from the system by the dry flue gas in the formula (3) can be calculated by the following formula:
Q2,gy＝Vgy,SNCRCp,gy,SNCR(tgy,ky,o,SNCR-tjz) (4)
in the formula: vgy,SNCRDry flue gas volume at air preheater exit, m, generated by combustion of fuel per unit mass with corresponding SNCR reactions3/kg；
Cp,gy,SNCR-commissioning SNCR post-air preheater exit flue gas from tjzTo tgy,ky,o,SNCRConstant pressure specific heat capacity, kJ/(m)3.K)。
tgy,ky,o,SNCR-temperature of flue gas at outlet of air preheater after SNCR commissioning at C.
tjzTest reference temperature, DEG C.
C in the above formula (4)p,gy,SNCRIs calculated according to a smoke component table look-up table, a specific algorithm is calculated according to a 45-page formula (73) of GB/T10184-2015, and Tgy,ky,o,SNCRAnd tjzAre measured in experiments.
V in the above formula (4)gy,SNCRIs calculated according to the following method:
Figure BDA0002923265310000071
in the formula:
Figure BDA0002923265310000072
theoretical flue gas volume, m, produced by combustion of a unit mass of fuel3/kg；
Figure BDA0002923265310000073
Air volume, m, required for the combustion theory of fuel per unit mass3/kg；
Figure BDA0002923265310000074
Volume of dry flue gas, m, produced by SNCR reaction per unit mass of fuel3/kg。
α -coefficient of excess air at the outlet of the air preheater after SNCR was put into service.
In the above formula (5)
Figure BDA0002923265310000075
Calculated according to the following equation (6):
Figure BDA0002923265310000076
in the formula: car-the received base carbon content of the fuel,%;
Sar-the received base sulphur content of the fuel,%;
Nar-the received basic nitrogen content of the fuel,%.
In the above formulae (5) and (6)
Figure BDA0002923265310000081
Calculated according to the following equation (7):
Figure BDA0002923265310000082
in the formula: o isar-the oxygen content of the fuel,%;
Har-the received base hydrogen content of the fuel,%.
The fuel in formulas (6) and (7) received levels of base carbon, hydrogen, oxygen, nitrogen and sulfur, which were determined from coal quality tests taken during the test.
α in the above formula (5) is calculated according to the following formula (8):
Figure BDA0002923265310000083
in the formula:
Figure BDA0002923265310000084
-volume fraction of dry flue gas oxygen at the outlet of the air preheater after commissioning of the SNCR,%;
in the above formula (5)
Figure BDA0002923265310000085
Is the volume of dry flue gas generated during the SNCR reaction. After entering the boiler, the urea reacts with the nitrogen oxides (mainly NO) in the boiler, and the final reaction product is N2、H2O and CO2Therefore, the overall package reaction equation for the reaction of urea and NO is:
Figure BDA0002923265310000086
in the formula: a, spraying ammonia nitrogen molar ratio of urea to NO in flue gas;
b-denitration efficiency of SNCR reaction system,%.
As can be seen from the reaction equation (9), the injection of 1mol of urea into the furnace will consume (b/a) mol of NO and (3a-b/2a) mol of oxygen in the dry flue gas, and release (2a + b)/2a mol of N into the dry flue gas2And 1mol of CO2. Subtracting the amount of the consumed dry flue gas component from the amount of the generated dry flue gas to obtain that spraying 1mol of urea into the hearth will result in 0.5mol of flue gas reduction, so the influence of spraying urea on the volume of the flue gas can be expressed as:
Figure BDA0002923265310000087
in the formula:
Figure BDA0002923265310000088
-the mass of urea solution injected into the furnace, kg/kg, corresponding to the unit mass of fuel SNCR.
The amount of urea in the SNCR system corresponding to the unit mass of fuel in the above equation (10)
Figure BDA0002923265310000089
Calculated by the following procedure:
a. measuring the moisture content d of the flue gas at the outlet of the air preheater after the SNCR denitration system is put into operationSNCR；
b. When the SNCR is not put into operation according to the test result of the sampled coal quality in the test process, the moisture content d in the flue gas at the outlet of the air preheater is calculatedno-SNCRThe calculation method is as follows:
Figure BDA0002923265310000091
Figure BDA0002923265310000092
in the formula:
Figure BDA0002923265310000093
h in outlet flue gas of non-operational SNCR (selective non-catalytic reduction) time-air preheater2O content, kg/kg;
dno-SNCRmoisture content, kg/m, corresponding to dry flue gas per unit volume of outlet of SNCR (selective non-catalytic reduction) time-air preheater3；
dSNCRMoisture content, kg/m, corresponding to unit volume of dry flue gas at outlet of SNCR (selective non-catalytic reduction) time-air preheater3；
Vgy,no-SNCRVolume of dry flue gas at outlet of air preheater when SNCR is not put into operation, m3/kg。
In the formula (12)
Figure BDA0002923265310000094
And
Figure BDA0002923265310000095
calculated according to equations (6) and (7)。
Quality of steam in outlet flue gas of air preheater when SNCR is not put into operation in formula (11)
Figure BDA0002923265310000096
The device mainly comprises the following parts:
(1) water vapor generated by burning hydrogen element in the fuel;
(2) water vapor evaporated from fuel moisture;
(3) water in the air.
Figure BDA0002923265310000097
In the formula: mar-the received base moisture content of the fuel,%;
hkq,ababsolute moisture content of air, kg/kg;
c. calculating the increment of the corresponding moisture content of the dry flue gas in unit volume after the SNCR denitration system is put into operation:
Figure BDA0002923265310000098
in the formula:
Figure BDA0002923265310000099
the difference value of the corresponding moisture contents of the dry flue gas at the outlet of the air preheater of the SNCR denitration system during operation and shutdown, kg/m3；
d. And converting the urea solution sprayed into the hearth by the SNCR denitration system to the fuel with unit mass.
It is known that: the concentration of the urea solution sprayed into the hearth by the SNCR denitration system is c, and the increase of the corresponding moisture content of the dry flue gas calculated by the formula (14) mainly comprises two parts: (1) spraying moisture carried by the urea solution into the furnace; (2) moisture produced by the SNCR reaction.
As can be seen from the formula (9), 2mol of water vapor can be generated by the reaction of 1mol of urea entering the furnace. Then the following relationship exists:
Figure BDA00029232653100000910
in the formula:
Figure BDA00029232653100000911
-the mass of the urea solution sprayed into the furnace corresponding to the unit mass of fuel SNCR, kg/kg;
c-mass fraction (concentration) and percent of urea in the urea solution;
from equation (15), the mass of the urea solution injected at c% concentration corresponding to the unit mass of fuel is calculated as:
Figure BDA0002923265310000101
2.2 Heat taken away by vapor in flue gas after operation of SNCR denitration system
Figure BDA0002923265310000102
Figure BDA0002923265310000103
In the formula:
Figure BDA0002923265310000104
volume of water vapour in flue gas at outlet of air preheater resulting from combustion of unit mass of fuel after SNCR put into operation, m3/kg；
Figure BDA0002923265310000105
Water vapour from tjzTo tgy,ky,o,SNCRConstant pressure specific heat capacity, kJ/(m)3.K)。
In the formula (17)
Figure BDA0002923265310000106
The calculation process is as follows:
after the SNCR denitration system is put into operation, the water vapor in the flue gas at the outlet of the air preheater is mainly obtained from the following aspects:
(1) water vapor generated by burning hydrogen element in the fuel;
(2) water vapor evaporated from fuel moisture;
(3) moisture in the air;
(4) after the SNCR denitration system is put into operation, the water brought by the urea solution;
(5) moisture produced by the SNCR reaction.
Figure BDA0002923265310000107
The specific heat capacity at constant pressure of steam in the formula (17)
Figure BDA0002923265310000108
This can be found in appendix E of GB 10184-2015.
T in formula (17)gy,ky,o,SNCRAnd tjzAre measured in experiments.
H in formula (18)kq,abIs the absolute moisture content of the air and can be obtained by measurement.
3. Lost heat Q caused by incomplete combustion of gas generated by combustion of unit mass of fuel after SNCR commissioning3，SNCR
The incomplete combustion heat loss of gas generated by unit mass of fuel after SNCR operation is mainly caused by incomplete combustion CO and H contained in the exhaust smoke2、CH4And CxHy, etc., can be calculated as follows:
Figure BDA0002923265310000109
in the formula:
Figure BDA0002923265310000111
and
Figure BDA0002923265310000112
in the outlet dry flue gas of the air preheaterCO、H2、CH4、CxHyVolume fraction of (c)%.
V in formula (19)gy,SNCRCalculated according to the formula (5),
Figure BDA0002923265310000113
and
Figure BDA0002923265310000114
measured by tests.
4. Lost heat Q caused by incompletely burning solids after combustion of unit mass of fuel after SNCR commissioning4，SNCR
The loss of heat generated by incomplete combustion of solid per unit mass of fuel after SNCR operation is mainly composed of heat contained in combustible substances in ash and slag generated by fuel combustion, and can be calculated according to the following formula:
Figure BDA0002923265310000115
in the formula: a. thear-fuel receives base ash,%;
Figure BDA0002923265310000116
-average mass fraction of combustible material in fly ash and slag%
A in the formula (20)arObtained by the industrial analysis of the test coal quality,
Figure BDA0002923265310000117
the combustible material is obtained by sampling fly ash and slag through tests and analyzing the combustible material.
5. Boiler heat dissipation heat quantity Q corresponding to unit mass fuel after SNCR operation5，SNCR
The heat loss of the boiler refers to the heat dissipated from the boundary inner furnace wall of the boiler system, auxiliary equipment and high-pressure and high-temperature pipelines in the boundary of the boiler system to the periphery of the environment. The size of the boiler heat dissipation loss is related to the heat load, the outer surface temperature, the ambient wind speed and the like of a boiler unit, so the boiler heat dissipation loss heat corresponding to the unit mass fuel of the SNCR which is not put into operation does not change obviously after the SNCR is put into operation, and the boiler heat dissipation loss can be found according to GB/T10184-2015 appendix I or actually measured according to GB/T8174 and GB/T17357.
6. Physical heat loss of ash Q corresponding to unit mass of fuel after SNCR operation6，SNCR
The boiler ash of the coal-fired power plant mainly has three part sources: the first is slag, the second is settled ash at the lower part of the economizer, and the third is fly ash at the dust remover. After the SNCR is put into operation, the ash physical sensible heat loss heat corresponding to the unit mass of fuel consists of the physical sensible heat of the three parts of ash, and can be calculated according to the following formula:
Figure BDA0002923265310000118
in the formula: omegalz、ωcjh、ωfh-mass fraction of slag, settled ash and fly ash in the fuel ash;
Clz、Ccjh、Cfh-specific heat of slag, settled ash and fly ash, kJ/(kg · K);
tlz、tcjh、tfh-temperature of slag, settled ash and fly ash, c;
Figure BDA0002923265310000119
-mass fraction of solid combustible material in slag, settled ash and fly ash,%.
In the test process, samples of slag, settled ash and fly ash are obtained by sampling at a constant speed at a slag falling port of a boiler, a settling chamber at the lower part of an economizer and a front flue of a dust remover. The specific heat of the slag, settled ash and fly ash can be estimated according to appendix F or appendix GB/T10184-201, and the temperature T of the slag, settled ash and fly ashlz、tcjh、tfhCan be calculated according to the temperature of the flue gas at the sampling position,
Figure BDA0002923265310000121
can be obtained by analyzing solid combustible substances of three ash samples. The mass fraction omega of the slag, the settled ash and the fly ash in the fuel ashlz、ωcjh、ωfhGenerally determined according to design values.
7. Heat loss Q due to SNCR reaction per unit mass of fuel7，SNCR
Compared with an SNCR denitration system which is not put into operation, the urea pyrolysis reaction and the oxidation-reduction reaction between ammonia gas and NO and O are increased in a hearth behind the SNCR denitration system. Urea ((NH) sprayed into hearth2)2CO) solution is first evaporated to dryness and heated to a molten state and undergoes a phase change and then a pyrolysis reaction to decompose into NH3And CO2The vast majority of the NH pyrolyzed to form reducible NOx3And CO2The pyrolysis reaction is not endothermic. Partial NH produced by pyrolysis of urea3Reacts with NO in the flue gas to generate N2And H2O, and simultaneously, partial oxygen and NH in the flue gas are consumed3The reaction to reduce NO is an exothermic reaction. In addition, part of NH3Also reacts with oxygen to form NO or N2. The reaction process of urea injection into the furnace can be described as:
CO(NH2)2(s)→CO(NH2)2(l) (22)
H2O(l)→H2O(g) (23)
CO(NH2)2+H2O＝CO2+2NH3 (24)
4NH3+4NO+O2＝4N2+6H2O (25)
4NH3+5O2＝4NO+6H2O (26)
therefore, the heat loss caused by the SNCR reaction of the urea solution sprayed into the furnace is mainly formed by three parts of cloth, namely, the urea is melted and phase-changed to absorb heat, the liquid water in the urea solution is heated and gasified to absorb heat, and the urea is chemically reacted to release heat, which can be expressed as follows:
Figure BDA0002923265310000122
in the formula:
Figure BDA0002923265310000123
melting phase change heat absorption capacity kJ/kg corresponding to unit mass of fuel urea;
Figure BDA0002923265310000124
the heat absorbed by the water heating gasification of the urea solution injected into the furnace, kJ/kgQ, corresponding to the unit mass of fuel7,fy,SNCRAnd the total heat release of pyrolysis, oxidation and reduction reaction of the corresponding unit mass of the fuel urea is kJ/kg.
The urea melts at 140 deg.C and decomposes at 180 deg.C, so that the urea melts and changes phase to absorb heat
Figure BDA0002923265310000125
Comprises the following steps:
Figure BDA0002923265310000131
the latent heat absorbed by water gasification in the corresponding unit mass of the fuel urea solution is as follows:
Figure BDA0002923265310000132
from the reaction equations (23) to (25), it can be seen that the ammonia gas generated by the pyrolysis of urea reacts with nitrogen oxides (mainly NO) in the furnace or with O2Reaction, the final product of the reaction is N2、H2O and CO2Therefore, the package reaction equation for the reaction of urea with NO is expressed as:
Figure BDA0002923265310000133
in the formula: a, spraying ammonia nitrogen molar ratio of urea to NO in flue gas;
b-denitration efficiency of SNCR reaction system,%.
Q-is the heat of denitration reaction, and the calculated result is that Q is 544+89.86b/a, kJ/mol
After the boiler achieves ultralow emission, the SNCR system cannot be closed in the test process, so that the initial concentration of NOx can refer to historical same-working-condition data or DCS parameters, and if the requirement on precision is not high, the alpha can also be a design value.
Figure BDA0002923265310000134
8. Q removal per unit mass of fuel after SNCR commissioning2,SNCR～Q7,SNCROther lost heat Q of boilers thanqt,SNCR
Q removal per unit mass of fuel after SNCR commissioning2,SNCR～Q7,SNCRThe heat loss of other boilers is not increased except the heat removed by the pebble coal and the cooling water system, and the two loss terms can be calculated according to GB/T10184-2015 according to the operation boundary conditions.
9. All input heat Q except the calorific value of the fuel entering the furnacewl,SNCR
All input heat except the fuel entering the furnace after the SNCR is put into operation is basically the same as the situation of the SNCR which is not put into operation, but the physical sensible heat brought by the urea solution is increased, and the physical sensible heat brought by cooling air and the air for atomizing the urea solution is merged into dry air due to participation in combustion, and specific expressions are as follows:
Figure BDA0002923265310000135
in the formula: qrl-physical sensible heat of the fuel, kJ/kg;
Qf,SNCR-the physical sensible heat brought in by the urea solution, kJ/kg.
Qgkq-physical sensible heat brought in by dry air, kJ/kg;
Figure BDA0002923265310000136
-the physical sensible heat, kJ/kg, introduced by the corresponding water vapour contained in the air per mass of fuel;
Qaux-heat brought in by auxiliary equipment in the system, kJ/kg.
The physical sensible heat taken in by the urea solution in formula (32) can be determined as follows:
Figure BDA0002923265310000141
in the formula:
Figure BDA0002923265310000142
-is the physical sensible heat of urea and water, kJ/kg;
Figure BDA0002923265310000143
Figure BDA0002923265310000144
in the formula:
Figure BDA0002923265310000145
-is the physical sensible heat of urea and water, kJ/kg;
Figure BDA0002923265310000146
the specific heat capacities of urea and water are kJ/(kg. K);
Figure BDA0002923265310000147
the temperature of the urea and water entering the boundary of the system, deg.C.
Other amounts of extraneous heat may be determined by reference to the method of GB/T10184-2015.
Second, test and calculation process
The invention discloses a method for calculating the boiler fuel efficiency of a coal-fired generator set by adopting an SNCR (selective non-catalytic reduction) denitration technology, which provides that the SNCR is sprayed into a urea solution in a boiler to be uniformly distributed on fuel with unit mass by measuring and calculating the difference value of the moisture content of flue gas after the SNCR is put into operation, thereby solving the problem that the quality of the fuel in the boiler and the urea solution in the boiler are difficult to accurately measure; the method introduces a new heat loss term of the boiler, namely an SNCR denitration reaction heat loss term, and comprises urea melting phase change heat absorption capacity, water gasification heat absorption capacity and SNCR reaction heat release capacity, and on the basis of denitration elementary reaction, provides a method for calculating the SNCR denitration reaction heat loss by adopting total package reaction.
The invention provides a method for calculating the boiler fuel efficiency of a coal-fired power generating unit by adopting an SNCR (selective non-catalytic reduction) denitration technology, which comprises the following steps:
1. under the condition of stable unit load required by the test, measuring the moisture content, the flue gas temperature, the oxygen content of the flue gas and CO at the outlet of the air preheater after the SNCR denitration technology is put into operation2、H2、CH4And CxHy concentration, and measuring the oxygen content and the flue gas temperature of the flue gas at the outlet of the economizer; taking raw coal from an inlet of a coal mill and carrying out industrial analysis and element analysis; taking the large slag and the fly ash from the designated position of the boiler and analyzing the carbon content; measuring the temperature and moisture content of the air near the inlet of the air blower; and measuring the flue gas temperature at the slag falling port or the slag temperature of the slag drying machine.
2. According to the results of industrial analysis and element analysis of the test coal quality, the moisture content of the flue gas at the outlet of the air preheater when the SNCR denitration technology is not put into operation is calculated by combining the moisture content of the air and the oxygen content of the flue gas at the outlet of the air preheater, and the moisture content is calculated by applying the formulas (6) to (8) and the formulas (11) to (13).
3. And (3) calculating according to the moisture content in the outlet flue gas of the air preheater of the SNCR denitration technology of commissioning and non-commissioning which is measured and calculated in the steps (1) and (2) to obtain a moisture content difference, calculating according to the concentration (urea mass fraction) of the urea solution sprayed into the furnace by the SNCR denitration technology to obtain the mass of the urea solution sprayed into the furnace by the corresponding unit mass of fuel, and calculating by applying the formulas (14) to (16).
4. Calculating the lost heat Q caused by the flue gas generated by the combustion of the fuel with unit mass after the SNCR operation according to the industrial analysis and the element analysis of the raw coal, the temperature and the oxygen content of the flue gas at the outlet of the air preheater, the moisture content of the air and the mass of the urea solution sprayed into the furnace corresponding to the fuel with unit mass measured in the step (1)2,SNCRThe calculation is performed by using the expressions (3) to (5) and the expressions (17) to (18).
5. According to the industrial analysis and the element analysis of raw coal, the flue gas CO and H at the outlet of the air preheater2、CH4And CxHy concentration and the mass of the urea solution sprayed into the furnace per unit mass of fuel, calculating the heat loss Q caused by incomplete combustion of gas generated by combustion of the unit mass of fuel after SNCR operation3，SNCRCalculated by using the formula (19).
6. According to the content of combustible substances of fly ash and large slag, the industrial analysis and the element analysis of the raw coal, which are measured in the step (1), calculating the lost heat Q caused by incompletely burning solid after the unit mass of fuel is burnt after the SNCR is put into operation4，SNCRCalculated by using equation (20).
7. According to GB/T10184-2015 appendix I, or according to GB/T8174 and GB/T17357, actually measuring boiler heat loss heat Q corresponding to unit mass fuel after SNCR operation5，SNCR；
8. According to the slag temperature, the economizer outlet flue gas temperature and the air preheater outlet flue gas temperature measured in the step (1), calculating the ash physical heat loss heat Q corresponding to the unit mass of fuel after the SNCR is put into operation6，SNCRCalculated by using the formula (21).
9. Calculating the heat loss Q caused by SNCR reaction relative to the unit mass of the fuel according to the mass of the urea solution sprayed into the furnace by the corresponding unit mass of the fuel and the mass concentration of the urea7，SNCRThe calculation is performed by using the expressions (27) to (31).
10. Calculating Q of the fuel of unit mass after the SNCR is put into operation according to GB/T10184-2015 and operation boundary conditions2,SNCR～Q7,SNCROther lost heat Q of boilers thanqt,SNCR；
11. Calculating all input heat Q except the calorific value of the fuel entering the furnace according to the temperature of the urea solution, the ambient temperature and the moisture content of the air and the temperature of the raw coalwl,SNCRCalculated by using the equations (32) to (35).
12. Based on the respective lost heat calculated in the above steps, the fuel thermal efficiency of the boiler is calculated by applying equations (1) to (2).
The above parameters are obtained and calculated as shown in fig. 1.
Third, calculate the example
The 660MW supercritical unit boiler is a II-type boiler with a model DG-2141/25.4-II12, and is a supercritical parameter, W-type flame combustion, a vertical tube ring water-cooled wall variable-pressure operation direct-current boiler, primary reheating, reheating steam temperature adjustment by a baffle, balanced ventilation, open-air arrangement, solid slag discharge, an all-steel framework and a full-suspension structure. .
The test working condition is 660MW load working condition, and the coal quality data and the test measurement data of the test working condition are shown in the following table:
Figure BDA0002923265310000161
Figure BDA0002923265310000171
boiler efficiency calculations after commissioning the SNCR system are shown in the table below.
Figure BDA0002923265310000172
As can be seen from the calculation results in the table, the boiler efficiency calculated by the method of the patent considering the influence of the SNCR on the heat loss term of the boiler efficiency is 92.8%, while the influence of the SNCR on the heat loss term of the boiler is not considered in GB10184/T-2015, the boiler efficiency calculated by the method is 93.36%, the difference between the two methods is 0.38%, and the coal consumption deviation is reduced to 1 g/kWh. The calculation method is more accurate.

Claims (11)

1. The boiler fuel efficiency calculation method adopting the SNCR denitration technology is characterized in that the boiler fuel efficiency eta isSNCRBy respectively calculating the heat loss rate q of exhaust smoke after the SNCR is put into operation2，SNCRGas incomplete combustion heat loss rate q3，SNCRHeat loss rate q of incomplete combustion of solid4，SNCRBoiler heat dissipation loss rate q5，SNCRAsh physical sensible heat loss rate q6，SNCRSNCR reaction Heat loss Rate q7，SNCROther heat loss rate q of boilerqt，SNCRPercent of external heat to lower calorific value of fuel qw1，SNCRObtaining; the SNCR reaction heat loss rate q7，SNCRThe method comprises the steps of urea melting phase change heat absorption, liquid water heating gasification heat absorption in urea solution, and heat loss rate caused by heat release of urea chemical reaction.
2. The boiler fuel efficiency calculation method according to claim 1, wherein the exhaust heat loss rate q is2，SNCRThe heat loss rate caused by dry flue gas generated by fuel combustion and the heat loss rate caused by heat carried out of the system by water vapor in the flue gas are included; the dry flue gas generated by the fuel combustion also comprises dry flue gas generated by SNCR reaction corresponding to the fuel of unit mass; the water vapor in the flue gas also comprises moisture brought by the urea solution and moisture generated by the SNCR reaction.
3. The boiler fuel efficiency calculation method according to claim 2, wherein the exhaust heat loss rate q is2，SNCR，％＝Q2，sNCR/Qnet，SNCRX 100; said Q2，SNCRFor lost heat, Q, caused by flue gas generated by combustion of unit mass of fuel after SNCR commissioningnet，SNCRThe lower calorific value of the fuel entering the furnace; the volume of dry flue gas generated by SNCR reaction corresponding to the unit mass of fuel
Figure FDA0002923265300000011
By calculating the mass of urea solution sprayed into the furnace by the SNCR system corresponding to the unit mass of fuel
Figure FDA0002923265300000017
Obtaining:
Figure FDA0002923265300000012
4. the method according to claim 3, wherein the amount of heat Q lost by flue gas generated by combustion of the SNCR-based fuel is calculated2，SNCRInvolving the heat Q taken away from the system by the dry flue gas2，gyAnd the heat taken away by the water vapor contained in the flue gas
Figure FDA0002923265300000013
Figure FDA0002923265300000014
Q2，gy＝Vgy，SNCRCp，gy，SNCR(tgy，ky，o，SNCR-tjz)；
In the formula (I), the compound is shown in the specification,
Figure FDA0002923265300000015
volume of air, m, required for the combustion theory of fuel per unit mass3/kg；
Figure FDA0002923265300000016
Volume of dry flue gas generated by SNCR reaction per unit mass of fuel, m3Per kg; alpha is the excess air factor at the outlet of the air preheater after the SNCR was put into service.
5. The boiler fuel combustion efficiency calculation method of claim 4, wherein the operational SNCR systemHeat carried away by water vapor contained in the rear flue gas
Figure FDA0002923265300000021
Calculated by the following formula:
Figure FDA0002923265300000022
in the formula (I), the compound is shown in the specification,
Figure FDA0002923265300000023
volume of water vapor in flue gas at outlet of air preheater generated by combustion of unit mass of fuel after operation of SNCR system3/kg；tjzTest reference temperature, deg.C; t is tgy，ky，o，SNCRThe outlet flue gas temperature of an air preheater at the rear of the operation of the SNCR system is DEG C;
Figure FDA0002923265300000024
is water vapor from tjzTo tgy，ky，o，SNCRConstant pressure specific heat capacity, kJ/(m)3·K)；
Volume of water vapor in flue gas at outlet of air preheater generated by combustion of unit mass of fuel after operation of SNCR system
Figure FDA0002923265300000025
The method also comprises the water brought in by the urea solution after the SNCR system is put into operation and the water generated by the SNCR reaction.
6. The method of calculating the fuel combustion efficiency of a boiler according to claim 5, wherein the SNCR system is put into operation to generate a volume of water vapor in flue gas at an outlet of an air preheater for combustion of a unit mass of fuel
Figure FDA0002923265300000026
Calculated by the following formula:
Figure FDA0002923265300000027
in the formula, HarIs the received base hydrogen content of the fuel,%; marIs the received base moisture content,%, of the fuel;
Figure FDA0002923265300000028
volume of air, m, required for the combustion theory of fuel per unit mass3/kg；hkq，abIs the absolute moisture content of air, kg/kg; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
7. The boiler fuel efficiency calculation method of claim 1, wherein the SNCR reaction heat loss rate q7，SNCRBy calculating the mass of urea solution sprayed into the furnace by the SNCR system corresponding to the unit mass of fuel
Figure FDA0002923265300000029
Obtaining:
Figure FDA00029232653000000210
in the formula, a-ammonia nitrogen molar ratio of sprayed urea to NO in flue gas; b-denitration efficiency of SNCR reaction system,%; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
8. The boiler fuel efficiency calculation method according to claim 1, wherein the gas incomplete combustion heat loss rate q3，SNCRThe calculation of the volume of the discharged smoke also comprises dry smoke generated by SNCR reaction corresponding to unit mass of fuel
Figure FDA0002923265300000031
Dry flue gas generated by SNCR reaction corresponding to the unit mass of fuel
Figure FDA0002923265300000032
By calculating the mass of urea solution sprayed into the furnace by the SNCR system corresponding to the unit mass of fuel
Figure FDA0002923265300000033
Obtaining:
Figure FDA0002923265300000034
9. the boiler fuel efficiency calculation method of claim 1, wherein the percentage q of the extraneous heat to the lower calorific fuel value isw1，SNCRThe external heat also comprises physical sensible heat Q brought by the urea solutionf，SNCR。
10. The boiler fuel efficiency calculation method according to claim 9, wherein the sensible physical heat Q brought in by the urea solutionf，SNCRCalculated by the following formula:
Figure FDA0002923265300000035
Figure FDA0002923265300000036
Figure FDA0002923265300000037
in the formula (I), the compound is shown in the specification,
Figure FDA0002923265300000038
the physical sensible heat of urea and water is kJ/kg;
Figure FDA0002923265300000039
Figure FDA00029232653000000310
the specific heat capacities of urea and water are kJ/(kg. K);
Figure FDA00029232653000000311
the temperatures of urea and water entering the system boundary, respectively, are in deg.C; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
11. The method for calculating the fuel efficiency of the boiler according to the claim 6, 7, 8 or 10, wherein the SNCR system for the unit mass of the fuel injects the mass of the urea solution in the boiler
Figure FDA00029232653000000312
Calculated by the following method:
Figure FDA00029232653000000313
in the formula (I), the compound is shown in the specification,
Figure FDA00029232653000000314
the difference value of the corresponding moisture content of the dry flue gas at the outlet of the air preheater before the operation of the SNCR system is kg/m3；Vgy，no-SNCRVolume of dry flue gas at outlet of air preheater before operation of SNCR system, m3Per kg; mass fraction of the urea solution sprayed into the hearth by the c-SNCR system is percent.
CN202110124868.2A 2021-01-29 2021-01-29 Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology Pending CN112933942A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110124868.2A CN112933942A (en) 2021-01-29 2021-01-29 Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110124868.2A CN112933942A (en) 2021-01-29 2021-01-29 Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology

Publications (1)

Publication Number Publication Date
CN112933942A true CN112933942A (en) 2021-06-11

Family

ID=76239426

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110124868.2A Pending CN112933942A (en) 2021-01-29 2021-01-29 Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology

Country Status (1)

Country Link
CN (1) CN112933942A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113282872A (en) * 2021-06-29 2021-08-20 广东电网有限责任公司 Method for calculating thermal efficiency of boiler of coal-fired thermal power generating unit in real time and related device
CN114459787A (en) * 2022-01-21 2022-05-10 广西壮族自治区特种设备检验研究院 Method, system and device for quickly testing thermal efficiency of industrial boiler

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113282872A (en) * 2021-06-29 2021-08-20 广东电网有限责任公司 Method for calculating thermal efficiency of boiler of coal-fired thermal power generating unit in real time and related device
CN114459787A (en) * 2022-01-21 2022-05-10 广西壮族自治区特种设备检验研究院 Method, system and device for quickly testing thermal efficiency of industrial boiler
CN114459787B (en) * 2022-01-21 2023-06-16 广西壮族自治区特种设备检验研究院 Method, system and device for rapidly testing thermal efficiency of industrial boiler

Similar Documents

Publication Publication Date Title
CN102012968B (en) Method for monitoring thermal efficiency and coal quality data of pulverized coal fired boiler in real time
Pei et al. Process simulation of oxy-fuel combustion for a 300 MW pulverized coal-fired power plant using Aspen Plus
Pfeifer et al. Comparison of dual fluidized bed steam gasification of biomass with and without selective transport of CO2
CN112933942A (en) Boiler fuel efficiency calculation method adopting SNCR (selective non-catalytic reduction) denitration technology
Zhu et al. NO emissions under pulverized char combustion in O2/CO2/H2O preheated by a circulating fluidized bed
CN203507793U (en) Device for simultaneously removing sulfur dioxide and nitrogen oxide from coke oven flue gas
CN105056758B (en) A kind of fluid catalytic removes the method and device of nitrogen oxides
CN103604133B (en) A kind of flue gas purification system of multi-pollutant integration dry removal and technique
Xu et al. The characteristics of recycled NO reduction over char during oxy-fuel fluidized bed combustion
Waldner et al. Energy from Waste–Clean, efficient, renewable: Transitions in combustion efficiency and NOx control
CN101870480B (en) Method for preparing ammonia gas from urea solid by dry pyrolysis
CN103087776B (en) Chemical Iooping combustion-based dry pulverized coal pressurized entrained-flow bed gasification method and chemical Iooping combustion-based dry pulverized coal pressurized entrained-flow bed gasification device
CN108671751A (en) A kind of chain grate-rotary kiln pelletizing equipment for denitrifying flue gas and application method
CN105228746A (en) The catalyst recovery process of COS reforming catalyst
Fang et al. The application of fly ash gasification for purifying the raw syngas in an industrial-scale entrained flow gasifier
CN107739036A (en) A kind of dry type urea pyrolysis ammonia system and method
Chein et al. Thermodynamic analysis of integrated adiabatic chemical looping combustion and supercritical CO2 cycle
Zarzycki et al. Modelling of the process of coal dust combustion in a cyclone furnace
Lu et al. Process design and thermal-calculation of a novel entrained-flow gasifier using fine ash as feedstock
CN208742297U (en) A kind of chain grate-rotary kiln pelletizing equipment for denitrifying flue gas
CN204952660U (en) Denitration dry desulfurization equipment in coal fired boiler flue gas stove
CN208186363U (en) A kind of system for pyrolyzing and burning of smoke backflow formula
CN204063013U (en) A kind of CFBB with TRT
CN112949981B (en) Evaluation method for influence of SNCR system on operation economy of coal-fired power generation unit
Ni et al. Experimental study on the effects of reheat temperatures on the ammonium bisulfate and ash blend deposition

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
CB02 Change of applicant information
CB02 Change of applicant information

Address after: 210023 fairyland Road, Qixia District, Nanjing, Jiangsu Province, No. 10

Applicant after: Guoneng Nanjing Electric Power Test Research Co.,Ltd.

Applicant after: State energy group Guangxi Electric Power Co.,Ltd.

Applicant after: National Energy Group Science and Technology Research Institute Co.,Ltd.

Applicant after: SOUTHEAST University

Applicant after: Guodian Nanning Power Generation Co.,Ltd.

Address before: 210023 fairyland Road, Qixia District, Nanjing, Jiangsu Province, No. 10

Applicant before: GUODIAN NANJING ELECTRIC POWER TEST RESEARCH Co.,Ltd.

Applicant before: State energy group Guangxi Electric Power Co.,Ltd.

Applicant before: National Energy Group Science and Technology Research Institute Co.,Ltd.

Applicant before: SOUTHEAST University

Applicant before: Guodian Nanning Power Generation Co.,Ltd.

SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination