QB/T 1493-1992 Determination and calculation method of thermal balance and thermal efficiency of flame tunnel kiln for daily ceramics

This standard specifies the determination and calculation methods of the heat balance and thermal efficiency of daily-use ceramic flame tunnel kilns. This standard applies to the determination and calculation of the heat balance and thermal efficiency of flame tunnel kilns using liquid, solid and gaseous fuels in the production of daily-use ceramic products. The determination and calculation of the heat balance and thermal efficiency of tunnel kilns producing other types of ceramic products can refer to this standard. Determination items can also be added or deleted according to the specific status of the kiln. QB/T 1493-1992 Determination and calculation methods of heat balance and thermal efficiency of daily-use ceramic flame tunnel kilns QB/T1493-1992 Standard download decompression password: www.bzxz.net

Light Industry Industry Standard of the People's Republic of China
Determination and calculation methods of thermal balance and thermal efficiency of flame tunnel kilns for daily-use ceramics
1 Subject content and scope of application
This standard specifies the determination and calculation methods of thermal balance and thermal efficiency of flame tunnel kilns for daily-use ceramics. QB/T 1493- 1992
This standard is applicable to the determination and calculation of thermal balance and thermal efficiency of flame tunnel kilns using liquid, solid and gaseous fuels in the production of daily-use ceramic products. For the determination and calculation of thermal balance and thermal efficiency of tunnel kilns for the production of other types of ceramic products, this standard can be used as a reference. It is also possible to increase the measurement items according to the specific status of the kiln. 2 Reference standards
GB/T211 Determination of total moisture in coal
GB/T212 Industrial analysis of coal
GB/T384 Determination of calorific value of petroleum products
3 Units, symbols and standards
3.1 Units
This standard adopts the national legal measurement unit (SI). For the conversion of calorie and joule, this standard stipulates the use of 20C calorie, that is, 1cal=4.1816J The conversion of millimeter water column and Pascal is: 1mmHO=9.8066Pa Note: In order to facilitate comparison with the current engineering unit system, the engineering unit value and its unit are attached in the text. 3.2 Symbols
See Appendix A (Supplement).
Temperature base 0C, that is, T. 273.15K.
Material base 1kg (product).
4 Measurement items and methods
4.1 Preparation before measurement
4.1.1 Organize measurement personnel to learn relevant measurement techniques and safety regulations, understand the significance of measurement, be familiar with instrument performance, and master measurement methods. 4.1.2 According to the measurement plan formulated in Table 1, make good job division of labor and measurement requirements for measurement personnel. 4.1.3 Refer to Appendix F to prepare the measurement instruments; make necessary calibrations to achieve the specified accuracy. 4.1.4 Understand the design, production and maintenance history of the measured tunnel kiln, and fill in the basic information of the tunnel density according to Appendix B Table B1. 4.1.5 Arrange measurement points, open measurement holes, install measurement instruments, and conduct single-item inspections. 4.2 Heat balance block diagram
Approved by the Ministry of Light Industry of the People's Republic of China on April 14, 1992140
Implementation on December 1, 1992
QB/T1493-1992
4.2.1 In heat balance calculation, in order to prevent the heat input and heat expenditure items from being forgotten, a block diagram is often used to show the heat input and heat expenditure items one by one, as shown in Figure 1. QhhQ
Figure 1 Heat balance block diagram
4.2.2 This standard divides the daily ceramic flame tunnel system. The outer surface of the kiln body is the boundary, and the air, oil, gas and steam pipelines are bounded by the nearest measuring point. The bottom of the kiln (including the pit under the car) is bounded by the ground plane. Outside the boundary (such as dryers, etc.) are not included in the system. Waste heat utilization is calculated separately.
Note: Waste heat boilers are included in the system.
, 3 Measurement time
4.3.1 The kiln must be stable for at least one firing cycle before the measurement can be carried out. 4.3.2 The total continuous measurement time shall not be less than one firing cycle. Note: The firing cycle refers to the time from the entry of the waste into the kiln to the burning into the product and leaving the kiln. 4.4 Measurement steps
4.4.1 First, conduct a pilot test on the tunnel density. 4.4.2 The production conditions such as raw materials, fuel composition and waste loading during the test and formal measurement should be consistent. 4.4.3 The measurement items and measurement methods shall be carried out in accordance with Table 1. 4.5 Calculation and analysis of measurement results
4.5.1 After the measurement is completed, the original data shall be systematically sorted. 4.5.2 Calculate the material balance, heat balance and thermal efficiency according to the contents of Chapters 5, 6 and 7. 4.5.3 Suspected data and missed items shall be supplemented and calculated. 4.5.4 Analyze and study the final calculation results, point out the problems and put forward suggestions for improvement. 4.6 Records and reports
4.6.1 Draw a measurement point layout diagram and write down the model and accuracy of the measurement instruments in accordance with the format of Appendix F. 4.6.2 The current situation of the tunnel kiln shall be filled in item by item according to Table B1 of Record B. 4.6.3 The comprehensive table of measured data shall be filled in item by item according to Table B2 of Appendix B. 141
Measurement items
Fuel entering the kiln temperature
Ambient air temperature
Leakage air temperature
·Combustion air entering the kiln temperature
5. Atomizing air entering the kiln temperature
6. Atomizing steam entering the kiln temperature
Air curtain entering the kiln temperature
8. Cooling air entering the kiln temperature
9. De-density Flue gas temperature
10. Flue gas inlet waste heat utilization
device temperature tyi+℃
11. Flue gas outlet waste heat utilization
device temperature tye, ℃
12. Exhaust hot air temperature
13. Ring body kiln temperature
14. Product kiln outlet temperature
15. Kiln car metal entry temperature
degrees, C
QB/T 1493—1992
Table 1 Measurement items and measurement methods
Measurement time
Selection of measurement points for full cycle recording of oil and gas
Oil or gas should be recorded in the pipeline before entering the kiln; coal should be measured for 2~4h; coal should be measured once in front of each firebox for each coal pile
in the place where air circulation is not affected by the kiln temperature
Mechanical air supply assists combustion in the pipeline before entering the kiln, and natural air supply assists combustion in the air circulation in front of the furnace
Center point in the cross section of the atomizing air duct before the burner
Center point in the cross section of the atomizing steam duct before the burner
Center point in the cross section of the atomizing steam duct before the burner
1~2㎡ in front of the air curtain duct
Every 2~4 h measurement-
every 2~4 hMeasurement-
Center point of the cross section
1~2m in front of the dense smoke pipe
Center point of the cross section
Center point of the intersection of the main flue and the branch flue
Inlet flue gas pipe of the waste heat utilization device
Center point of the dynamic ballast surface
Exit flue gas pipe of the waste heat utilization device
Center point of the dynamic pressure cross section
Center point of the hot air duct
Center point of the cross section
1~2m away from the dense smoke pipe
Center point of the top and middle corners of the kiln car
Measurement method
Use resistance thermometer and glass thermometer to measure and take the average value
Use thermocouple and mercury thermometer to measure and take the average value
Take the front, back, left, right and middle of the kiln car! Products in the pot
Use thermal resistance thermometer, gauge
kiln car metal wind part to measure before, after and wheel
times, before entering the kiln and out of the kiln
16. Kiln car metal out of the kiln temperature, teC
17. Kiln car refractory lining brick
kiln temperature, ℃
measure within 10 minutes after
surface thermometer or point thermometer
t||Measurement, take the average value
Specified items
18. Densification temperature of refractory bricks, ℃
19. Temperature of bricks entering the kiln
20. Densification temperature of heavy bricks
21. Temperature of auxiliary materials entering the kiln, ℃
22. Temperature of auxiliary materials leaving the kiln
23. Maximum firing temperature of products
QB/T 1493-1992
Table 1 continued)
Measurement time
Measure every 2~4 hours, measure within 10 minutes before entering the kiln and after leaving the kiln
Full measurement period
24.The average temperature of ash and slag is measured at four points at the four corners and four points at the center of each surface around the car. Two points are evenly distributed on the vertical and horizontal center lines, and two holes are evenly distributed on the diagonal lines to the center of the platform, as shown in the figure below. Pre-distribute the temperature on two representative cars, or use the thermal method to calculate. ○ Temperature measurement points on the platform surface Go to the temperature measuring hole in the center of the platform
Dense car front, rear, left, right and middle column
body, take the average temperature inside and outside the pot
Dense car front, rear left, right and middle column
body take points
Measurement method
Use thermal resistance thermometer, surface thermometer or point thermometer to measure
measure and take the average value
Choose three representative kiln cars for temperature measurement
Use standard SK Triangular temperature measuring car, on the same section of each car, press the dimension, select the appropriate cone number, and put the nine points of upper, middle, lower, left, middle and right into the nine temperature measuring dimensions in the bowl. Before the ash leaves the grate, 25. The average temperature of each measuring area of ​​the dense item. 26. The average temperature of each measuring area of ​​the kiln wall. 27. The temperature in the furnace. 28. The temperature of the water entering the furnace. The measurement is carried out at the beginning, and the mud seat is inserted into the measurement according to the standard. The average value is taken, and the exposed-silicon-mounted thermocouple and the depth of the ash layer in the grate of each furnace are used!
【Measured with electronic potentiometer, take
First use point thermometer or surface thermometer
to find the surface temperature change
average value
Use surface thermometer or point thermometer
】The area close to each other is a measurement area. In the measurement area, measure with thermometer, take the average temperature. Select several measuring points at the top, middle and bottom of the wall as the temperature of each measurement area. Select several measuring points at the left, middle and left of the kiln roof. Use platinum-platinum thermocouples and electric thermometers
at the furnace mouth and various holes
before the waste heat boiler enters the furnace and after it comes out of the furnace
every 2 to 4 hours Measurement-
29. Temperature of steam out of furnace
30. Temperature of emulsified water of heavy oil
On the pipeline in front of emulsification device
Measured by sub-potential difference meter
Measured by glass thermometer or point thermometer
Measurement items
1. Average heat flux
density qd on kiln roof surface, W/m2
2. Average heat flux
density on dense wall surface, W/m2
3. Surface area of ​​each measuring area of ​​dense body
1. Pipe cross-sectional area at measuring point
2. Dynamic pressure pr,Pa
3. Flow velocity wi+m/s
4. Pipe cross-sectional area at measuring point
5. Dynamic pressure pm.Pa
6. Flow velocity wm+m/s
7. Cross-sectional area of ​​pipe at measuring point
Dynamic pressure rPa
9. Flow velocity, m/s
10. Cross-sectional area of ​​pipe at measuring point
Product Awm2
11. Dynamic pressure pw, Pa
12. Flow velocity wm, m/s
Atomizing steam flow
Cross-sectional area of ​​pipe at measuring point
Product Ai+m2
15. Dynamic pressure p, Pa
16. Flow velocity m/s
QB/T 1493—1992
Table 1 (continued)
Measurement time
At the beginning of measurement
Before measurement
Every 4 hMeasure once
Before measurement
Measure every 4h
Before measurement
Measure every 4h
Before measurement
Measure every 4h
Overall measurement period
Before measurement
Every 4h Measure once
Selection of measuring points
Use a point thermometer or surface thermometer to find
the area with similar surface temperature change is defined as one
whole kiln surface
the straight part of the air duct (>3D) is selected
Measurement method
Use a contact heat flow meter or a non-contact
contact heat flow meter to measure the heat
flow density of each point; or use a point thermometer or a surface
thermometer to measure and calculate
Use a ruler to actually measure and calculate
Measure with a steel tape measure Calculate after measurement
Pitot tube and compensated micromanometer
or inclined pressure gauge
According to Appendix G at the measured section
Determine the number of measuring points
Select the surface at the straight part of the duct (>3D)
Measurement by hot-ball electric anemometer
Calculate after steel tape measurement
Pitot tube and compensated micromanometer
According to Appendix G at the measured section or inclined pressure gauge to determine the number of measuring points
Select the surface at the straight part of the duct (>3D)
Hot-ball electric anemometer Anemometer measurement
Calculate after measuring with a steel tape measure
Pitot tube and compensated micromanometer
According to Appendix G at the measured section or determine the number of measuring points with an inclined pressure gauge
Hot-ball electric anemometer measurement
Select the surface at the straight pipe part of the air duct (>3D)
Calculate after measuring with a steel tape measure
Pitot tube and compensated micromanometer
According to Appendix G at the measured section or determine the number of measuring points with an inclined pressure gauge
Select the surface at the steam main pipe before the burner
Straight pipe of air duct Select the surface at the part (3D)
Measurement by hot-bulb electric anemometer
Measurement by steam flowmeter
Measurement by steel tape measure and calculation
Pitot tube and compensated micromanometer
or inclined pressure gauge
Determine the number of measuring points according to Appendix G at the measured section
Measurement by high-temperature anemometer
Measurement items
17. Pipeline cross-section area at the measuring point Aym2
18, dynamic pressure pyPa
19. Flow rate 4+m/s
1. Fuel consumption m
kg/kg product
2. Kiln car metal mass m
kg/kg product
3. Density car refractory lining brick mass
mn, kg/kg product
4. Density mass of kiln mra
kg/kg product
i5. Kiln product mass mb
6. Pituitary mass ms, kg!
kg Crystal production
7. Quality of auxiliary materials
miakg/kg Product
18. Ash mass, m, kg
kgProduct
19. Evaporation volume of waste heat boiler
mz.kz/kgProduct
10. Emulsified water volume of heavy oil
mu.kg/kgProduct
Composition of combustion products, %
2.Flue gas composition, %
Low heating plate of fuel
Qw* kJ /kg fuel
(kJ/m fuel）
QB/T 1493 - 1992
Table 1 (continued)
Sputtering time
Before determination
Every 4 h Measurement times
Full measurement cycle
Before measurement
Full measurement cycle
Before measurement
While maintaining the ash of each furnace
Selection of measurement pointsbZxz.net
Summary of the straight pipe part of the flue (>3D)
Measurement method
Measurement with steel ruler and calculation
Pitot tube and compensated micromanometer
At this measurement point, confirm the number of points according to Appendix G or the number of decomposition pressure gauge
Oil and gas fuels at On the pipeline before the dense coal: coal is measured in the coal pile in front of each firebox. Select representative dense coal cars. Each dense coal place is selected. Overall or randomly select 10 types of crystal-producing coals. Under the condition of consistent slag thickness, the whole measurement cycle is carried out. The whole measurement cycle is carried out every 2~4h. The tidal volume is selected at a fixed time within a fixed period to release the coal. In the ash pit of each firebox, |tt||Water inlet main pipe
On the pipeline in front of the oil-water mixing device
Take samples in the secret passage respectively
Collect the samples in the middle of the flue section
High-temperature anemometer measurement machine
Oil and gas are measured with flow meters, and coal is weighed in front of the furnace
Use a calibrated scale to actually weigh
the quality of metal parts and lining bricks:
Converted from the whole cycle
Record the number of broken bodies and unit weight of each secret car And its type, calculate after measuring the total amount of each car, calculate the total amount after random sampling and weighing, actually weigh the load on each car, use a calibrated phosphorus scale to directly weigh the discharge of carbon slag, and convert it from the whole week; or calculate the whole cycle consumption according to the mass fraction of ash in the coal consumed by the fuel science and the carbon content in the ash, and take the average value. -Generally use a transfer flow meter to take four samples and then use a gas analyzer to measure and record them on site, and the average value is the low calorific value of the fuel. It can be measured by a special calorimeter, or it can be calculated according to the composition of the fuel before entering the pipeline for oil and gas fuels. Take samples from the bypass pipeline in the furnace, and use the Austrian gas analyzer to analyze the gas of the coal fuel. Then calculate: Sampling should be done from the coal pile near the firebox. The coal should be analyzed by elemental analysis or industrial analysis. For details, see Appendix C. Specific items 2. Average water content of the ring body 3. Chemical composition of the body ash content in the coal 5. Fuel moisture content W.% Carbon content in the ash 7. Working pressure of the waste heat boiler petPa Note: D is the diameter of the measuring pipe. 5 Material balance calculation method 5.1 See Figure 2 for the material balance diagram.
5.2 Income Items
QB/T 1493. 1992
Table 1 (Complete)
Measurement time
Measurement time every 4 hours
Measurement frequency
Measurement time every 4 hours
Full measurement period
5.2.1 Mass of impurity in the annulus ma, kg/kgProduct selection of measurement points
Joint sample at the corner of the middle layer of the impurity car
Joint sample of coal pile in the fire box
Sampling in the ash pool before leaving the kiln
Into the main pipe
Figure 2 Material balance diagram
5.3 Expenditure Items
5.3.1 Mass of impurity product m, calculated as 1kg
5.3.2 Mass of free water in the annulus m, kg/kgProduct mm In W
, W. is the average relative moisture content of the bulk,%. 5.3.3 Loss on ignition of dry bulk, mi, kg/kg product, mmgm
Determination method: Place the bulk to be measured at temperature in a weighing bottle with a constant weight, and weigh it with a balance with a sensitivity of 0.001g. Calculate the mass of the bulk! Then dry it in a drying oven at 105℃ to constant weight. Weigh the dry mass m, then ((mm2)/m×100, that is, the moisture content. Take the sample after the moisture content is determined for chemical analysis. See GB/T 211 and GB/T 211. Generally, an industrial single-bulk elastic pressure gauge is used for measurement. Take the average value of the whole closed period (1): mg QB/T 1493-1992 dry mass kiln mass, kg/kg product. mg = m.(l - W,)
5.4 Material balance
m=m+m,+m
6 Heat balance calculation method
6.1 Heat intake
6.1.1 Chemical heat of fuel combustion Q.kJ/kg product Q m·Qm
Where: m. Fuel consumption, kg/kg product or m/kg product; Qiw—low calorific value of fuel application base, kJ/kg fuel or kJ/m fuel, see Appendix C. 6.1.2 Sensible heat of fuel Q.kJ/kg product Q- mc t.
If the water content in the fuel is high, Qx=m,·［(1-W.）·C+4.1816 W.] Where: - fuel temperature entering the kiln, C;
fuel moisture content, %;
C fuel specific heat capacity, kJ/(kg·C) or kJ/(m2·C), see Appendix E Table E1 for coal specific heat capacity. Heavy oil fuel, =1.74+0.0025t
Gas fuel: -0.01Z(, c)
Where: r; - volume fraction of each gas in the fuel or flue gas, %; - average specific heat capacity of each gas component, kJ/(m2·C), see Appendix E Table E4. 6.1.3 Sensible heat brought by combustion air Q+kJ/kg product Qk = Vk * Ck + tk
Specific heat capacity of combustion air, kJ/(m.℃), see Appendix E Table E4, where: ck——.
—Temperature of combustion air entering the kiln, C;
Vk—Amount of combustion air, m\/kg product. Vh= as·m.·V?
Where: αs\
Average excess air coefficient in the burning zone;
V——-Theoretical air volume, m/kg or m2/m\fuel, see Appendix D. When burning oil, if the temperatures of atomizing air and combustion air entering the kiln are different, their flow rates and sensible heat brought in should be calculated separately. Qkk = VkCk- th + Vkw Ck
Wherein: Qk—sensible heat brought in by atomizing air and combustion-supporting air, kJ/kg product; atomizing air volume, m3/kg product, actually measured; Vaw
-specific heat capacity of atomizing air, kJ/(m3C), see Table E4 in Appendix E; th————-temperature of atomizing air entering the kiln, C. 6.1.4 Sensible heat brought in by atomizing steam Q. .kJ/kg product Qa = 1, 93 ma - tg
Wherein: 1.93-—average specific heat capacity of atomizing steam between 0 and 250°C, kJ/(kg°C); m3—mass of atomizing steam, kg/kg product (for the conversion of steam volume and mass, see Table E8 in Appendix E); t
temperature of atomizing steam entering the kiln, ℃.
6.7.5 Sensible heat of water used for heavy oil emulsification Qw kJ/kg product Qw = 4.181 6 mw *tw
QB/T 1493 - 1992
Where: 4.1816—.-Specific heat capacity of water, kJ/kgC)mw-.-Mass of water used for heavy oil emulsification.kg/kg product; tw.
Heavy oil emulsification water temperature, C.
6.1.6 Sensible heat of gas curtain Qm.kl/kg product QmVm\Cm*tm
Where: - Gas volume for air curtain kg product +
Cm-Specific heat capacity of gas for air curtain, kJ/mC), see Appendix E Table E4;. Gas curtain gas temperature, C.
6.1.7 Preheating zone leakage air brings people sensible heat Q, kJ/kg product Qu=(Vu- V.) \ cu*t.
Where: c. Specific heat capacity of preheated air, J/(mC), see Appendix E Table E4 Preheated air leakage temperature, ℃:
V. Preheated air volume, m/kg product. V=m(a,-a,).V
Where a is the excess air coefficient in the exhaust flue gas. 6.1.8 Sensible heat brought by cooling air Q.kJ/k product Q (Vi. c)
-Vyac,*ty +Vcat+V,c,-ti+V.*ce-te（10）
Wherein: VVVV represents the air supply volume of direct cooling air at kiln tail, rapid cooling air, indirect cooling air and cooling air under the car, m2/kg product;
represents the cold air specific heat capacity of direct cooling air at kiln tail, rapid cooling air, indirect cooling air and cooling air under the car, kJ/(m2, C), see Appendix E Table E4;
represents the cold air entering the kiln temperature w
of direct cooling air at kiln tail, rapid cooling air, indirect cooling air and cooling air under the car, ℃.
6.1.9 Sensible heat brought into the ring body Qs, kJ/kg product Q=Q+Q=m(1-W)cg+t+4.181 6mg*W*tWhere: .Sensible heat brought into the dry ring body, .kDense product., QSensible heat brought into the free water in the ring body, kJ/kg product.Average specific heat capacity of dry ring body, kJ/kg·), see Appendix E Table E3tTemperature of dense ring body, C.
6.1.10 Sensible heat brought into the kiln car Q.kJ/kg product Q. = Q+ Qn -- mis* C *+ + m * C* In the formula: Q. Sensible heat brought into the kiln car, kJ/kg product; Q. Sensible heat brought into the refractory lining bricks of the kiln car, kJ/kg product, mi and ms\ represent the masses of the kiln car metal and refractory lining bricks respectively, kg/kg product; C.…Specific heat capacity of the kiln car metal, taken as 0.5k/(kg·); ​​Gh
Specific heat capacity of the refractory lining bricks brought into the kiln by the kiln car, kJ/kg·C), see Appendix E Table E3*t and t· represent the temperatures of the kiln car metal and refractory bricks entering the kiln respectively, C. 6.1.71 Sensible heat of the main material Q, kJ/kg product Qh = -Q: + Q
m·+mc
Wherein: Q is the sensible heat of the main material, kJ/kg product; 148
( 15 )
B/T 1493-- 1992
Q is the sensible heat of the auxiliary material, kJ/kg product: hm—represents the mass of the main material and auxiliary material, kg/kg product, chr—represents the specific heat capacity of the main material and auxiliary material when densely packed, kJ/(kg·C), see Appendix E Table E3; m—represents the temperature at which the main material and auxiliary material enter into density, C. 6.1.12 Total heat input Q, kJ/kg product
QQ + Q+Q (or Q)→Q + Q +Qm→ Q + Q + Q- Q + Q.. 16)6.2 Heat expenditure
6.2.1 Sensible heat brought out by the product Q:, kJ/kg productQ,=mgc,t
Where: cg-—average specific heat capacity of the product, J/(kg·C), see Appendix E Table E3; to —temperature of the product out of the kiln, ℃.
6.2.2 Heat consumption when evaporating water in the annular body and heating water vapor to the temperature of the dense flue gas Qm, kl/kg product Q = Q + Qju mz(2 490 +1. 93 t) + 670 0 ma Where: Q-heat consumption when evaporating free water in the annular body and heating it to the temperature of the dense flue gas, kJ/g product, Qn--heat consumption when dehydrating structural water in the annular body, kJ/kg product, uniform temperature of the dense flue gas, ℃
2490--heat required for evaporation of each kilogram of free water at 0C, kJ/kg6700--heat required for dehydration of each dry gram of structural water kJ/kgm.
mass of structural water in the annular body, kg/k product. m (w+W.)
represents the mass fraction of magnesium and calcium oxide in the dry annular body, %. Since the amount of moisture brought in by the air is small, the heat consumption when heating this part of moisture can be ignored. 6.2.3 Heat consumption of physical and chemical reactions during the sintering process of the ashes: 2, kJ/kg product Qh m mg - (2 100W. -+ 282 3W, + 274 7W.) In the formula: 21002823.2747~~ are the decomposition heat of aluminum oxide, calcium oxide and magnesium oxide per kilogram, kJ/kg-mass fraction of aluminum oxide in the dry ashes:%. 6.2.4 Heat consumption of the formation of glass phase during the sintering process of the ashes: Q, kJ/kg product Q = 347 W. +m
In the formula: 347—-Heat consumption of the formation of each dry gram of glass phase in the product, kJ/kgW. Mass fraction of glass phase in the product,%. 6.2.5 Heat carried away by the kiln QkJ/kg product Q' Q + Q = mi*C\ti + mn'c+ * t. In the formula: Qi is the sensible heat carried away by the dense metal kJ/kg product; Q is the sensible heat carried away by the dense refractory brick kl/kg product; Q is the specific heat capacity of the refractory brick when leaving the kiln kJ/kg·C), see Appendix E Table E3; and Q represents the temperature of the dense metal and refractory brick leaving the kiln, C respectively. 6.2.6 Sensible heat brought out by kiln furniture materials Qi, k/kg product Qbf -- Q + 2e - m * c - th -+ m+ c * t Where: Q.—Sensible heat brought out by the kiln sagger, kJ/kg product, Q-Sensible heat brought out by auxiliary materials, kJ/kg product cc—-represents the specific heat capacity of the kiln sagger and auxiliary materials when they leave the kiln, kJ/(k·C), see Appendix E Table E3; (17
.. 18)
. (20)
—1992
OB/T 1493
ti.t.-represents the temperatures of the kiln sagger and its auxiliary materials when they leave the kiln, C. 6.2.7 Sensible heat carried away by dry flue gas Q,, kJ/kg product Q, = m, V*c,-t,
Specific heat capacity of dry flue gas, kJ/(m2·C); c, - 0. 012(α, +c)
V-the amount of dry flue gas leaving the kiln, m2/kg fuel or m2/m2 fuel. Note: For the calculation method of V;, see D3 in Appendix D. (23)
6.2.8 The sensible heat brought out by water vapor in the flue gas (including water generated by fuel combustion, emulsification water, and atomizing steam when heated to the temperature of the flue gas leaving the kiln) is Q:, kJ/kg product
Q = (m - mw)(2 490 + 1.93 t) + 1.93 m* t) where: m:
—-mass of water generated by fuel combustion, kg/kg product m=mm.
Note: For the calculation of m, see D2 in Appendix D.
6.2.9 Heat dissipation loss Q on the surface of dense body, kJ/kg product 6.2.9.1 In principle, the heat flux meter method is used to measure and calculate the kiln wall and kiln top in sections. The calculation formula is: Qm - 3. 6E(g - A,)/m
Where: 9;--the average heat flux density of each measuring area of ​​the kiln body, W/m, A---the surface area of ​​each measuring area of ​​the kiln body, m\; mi--the hourly mass of the product, kg/h.
6.2.9.2 The heat dissipation Q of the kiln body can also be calculated by the traditional formula, kJ/kg product Qm = Qur + Qdm
Where: QumQdm
Where: tuta-
Where: tusatvtgx
Represents the heat dissipation loss of the kiln wall and dense top surface, kJ/kg product respectively. Qm = [Ea · (tu, to) · Ag]/mbQam = [Eaa · (tdi to)· Ad, J/mb respectively represent the average surface temperature of each measuring area of ​​the kiln wall and kiln roof, C; the temperature of the surrounding air, C;
respectively represent the surface area of ​​each measuring area of ​​the kiln wall and kiln roof, m. +ban
i tdu+ tdzi
i tdz + td
respectively represent the temperature of the upper, middle and lower measuring points of the kiln wall, C; td: atdztay
respectively represent the temperature of the left, middle and right measuring points of the kiln roof, C; (24)
auivar————respectively represent the comprehensive heat transfer coefficient of the kiln wall and kiln roof to the air measured in the first section, kJ/(m·h·℃). +2734
it+273
ag, = 9. 20 (ta — ta) +
ad: = 11. 70 V(ta.
tai — ta
In the formula: ε--the blackness of the outer surface of the kiln body, generally taken as 0.8~0.9 (see Appendix E Table E7 for the blackness of various materials). 6.2.10 Sensible heat carried away by the hot air extraction Q, kJ/kg product 150
QB/T 1493-1992
Qi - ErV; - ct) -V!-c,.t +V -ct + V'ct*.*( 27)
Wherein: W!..V..--represent the hot air extraction volumes of direct hot air extraction, indirect hot air extraction and under-car hot air extraction, m\/kg product; cr-
-represent the average specific heat of hot air for direct hot air extraction, indirect hot air extraction and under-car hot air extraction, kJ/(m·C), see Appendix E Table E4:
, t,-represent the hot air outlet temperature of direct hot air extraction, indirect hot air extraction and under-car hot air extraction, C respectively. 6.2.11 Heat loss of chemical incomplete combustion Qha.kJ/kg product Qh - 12 628r · V;
Wherein: 12628
——reaction heat of carbon monoxide per cubic standard meter, kJ/m2; o
volume fraction of carbon monoxide in dry flue gas, %. 6.2.12 Heat loss of mechanical incomplete combustion QibkJ/kg product Q 33 871(m, - m, : Wh)
Wherein: 33871—-reaction heat per dry gram of carbon, kJ/kgWh——-mass fraction of ash in coal, %; m——mass of ash.kg/kg product. Actual weighing or calculation by the following formula: m,·W
Wherein: W-
carbon content in ash, %.
6.2.13 Sensible heat carried away by ash Q:.kJ/kg product Q -- m+ cf - t.
Where: c.-specific heat capacity of ash, kJ/(kg·℃), see Appendix E Table E6; t—average temperature of slag, ℃.
6.2.14 Heat absorption during evaporation of waste heat boiler water Qw, kJ/kg product Qw- mw.(HH)
Where: m—evaporation amount of waste heat boiler water, kg/kg product; H. —-heat roasting of steam out of furnace, kJ/kg, see Appendix E Table E2 Hw——heat roasting of water entering furnace, kJ/kg, see Appendix E Table E2. 6.2.15 Radiant heat loss from furnace mouth and its holes QkJ/kg product Qt =C. [1+273] - (+ 273] ]
Where: C
Blackbody radiation coefficient, equal to 20.4kJ/(hm2.K*); Average temperature in the furnace,
A. Orifice radiation area, m,
.A,.0/mi
5——Door hole coefficient, depends on the shape and size of the small hole and the thickness of the kiln wall, see Figure 3. 6.2.16 The sensible heat brought out by the exhaust gas from the cooling zone and the escaping gas from the kiln door Qi, kJ/kg product Qi = Qp + Qm = Vch · ti + Vm * cm + tm Where: QiQm—is the sensible heat of the exhaust gas from the cooling zone and the heat loss of the gas escaping from the kiln door, kJ/kg product; ViVlm—is the amount of gas discharged from the cooling zone and the kiln door, m/kg product; cic—is the specific heat capacity of the gas discharged from the cooling zone and the kiln door, kJ/(m2, C); titl is the temperature of the gas discharged from the cooling zone and the kiln door, C. .-..( 28)
（30）
（31)
（32)
（33)
6.2.17 Other heat losses Q, kJ/kg product, including the heat loss of the gas escaping from the opening of the kiln door and the holes in the kiln body, the heat loss from the bottom of the kiln to the foundation, and the heat of fuel combustion consumed by iron oxide reduction.
Q =Q - (Q: + Q +Q + Q+ Q +Q +Q +Q151
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