Some standard content:
ICS27.060
Machinery Industry Standard of the People's Republic of China
JB/T 3271-2002
Replaces JB/T3271—1983
Technical conditions for travelling grate stokers
Specification for travelling grate stokersIssued on 2002-07-16
Implemented on 2002-12-01
Issued by the State Economic and Trade Commission of the People's Republic of ChinaForeword
Scope．
Normative references
3 Terms and definitions
Technical requirements
4.1 Basic performance of chain grate.…
4.2 Basic requirements for chain grate design
4.3 Manufacturing
4.4 Assembly,
Inspection and testing
5.1 General requirements for inspection and testing
5.2 Appearance and dimension inspection..．
5.3 Mechanical transmission cold test,
5.4 Cold performance test of air supply system
5.5 Inspection and test records,
6 Paint packaging
Appendix A (Normative Appendix) Cold performance test method of chain grate air supply system A. Test bench
A.2 Layout of measuring points and corresponding instruments. A.3 Test conditions
A.4 Test data arrangement and calculation formula
Figure 1 Edge deviation of section of steel assembly.
Figure 2 Wall panel installation deviation
Figure 3 Difference in length of plane diagonal lines on the wall panels of the brackets on both sidesFigure 4 Height deviation and spacing deviation of guide rails.
Figure 5 Distance between sprocket and axis midpoint.
Figure 6 Height deviation of each beam of beam-type chain grate, Figure 7 Deviation of center line of upper and lower guide rails of beam-type chain grate, Figure A.. Schematic diagram of cold wind dynamic test bench
Figure A.2 Schematic diagram of measurement point arrangement on grate.
Table 1 Grate lateral air distribution unevenness coefficient p: Table 2 Average air pressure p in wind chamber
Table 3 Air retention rate B and air blow-by rate Sin of wind chamberTable 4 Flow rate M when air door is fully closed
JB/T 3271—2002
JB/T 32712002
This standard replaces B/T3271-1983 "Technical Conditions for Chain Grate". Compared with JB/T3271-1983, the main changes of this standard are as follows: the scope of application originally only includes chain belt chain grate and scale chain grate, and now the crossbeam chain grate is added (the opening words of the 1983 version; Chapter 1 of this version);
- The basic performance requirements of chain grates are added, such as the combustion efficiency, area heat load and coal type used and the performance of the air supply system of chain grates (4.1, 4.2.2, 4.2.6 of this version); - The test requirements, test methods and qualified standards of the air supply system of chain grates are added (4.1.4, 5.4 of this version); the dimensional deviations and requirements of the main parts of the original standard push chain belt grate and scale grate are deleted, and the requirements for assembly are adjusted. Some requirements are improved (1.2, 1.3, 1.4 of the 1983 version; 4.3, 4.4 of this version). Appendix A of this standard is a normative appendix.
This standard is proposed by China Machinery Industry Federation. This standard is under the jurisdiction of National Technical Committee for Boiler Standardization (CSBTS/TC73). The drafting units of this standard are: Beijing Electrical Technology and Economic Research Institute, Beijing Kangpei Combustion Equipment Complete Set Co., Ltd., Shanghai University of Technology, Beijing Boiler Research Institute.
The main drafters of this standard are: Yu Naiyue, Zhang Yuanzhong, Zhang Yongfu, Ji Faming, Zhang Wuxun, Tan Meijian. The previous versions of the standards replaced by this standard are: -JB3271-1983, JB/T3271-1983. II
1 Scope
Technical conditions for chain grates
JB/T3271---2002
This standard specifies the technical requirements (including basic performance, design, manufacturing and assembly), inspection and testing, and paint packaging of chain grates.
This standard applies to chain-belt chain grates, scale chain grates and beam chain grates using coal as fuel. Chain grates burning biomass fuels can be used as a reference.
2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated referenced documents, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties who reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, its latest version shall apply to this standard GB/T1800.3 Limits and basis of fit Part 3: Standard tolerances and basic deviations numerical table GB/T6414 Dimensional tolerances and machining allowances for castings GB/T18342 Technical conditions for coal used in chain grate boilers JB/T1615 Technical conditions for paint and packaging of boilers JB/T3375 Rules for factory acceptance of materials for boilers JB/T10094 General technical conditions for industrial boilers 3 Terms and definitions
The following terms and definitions apply to this standard. 3.1
Duration of continuous operation The duration of uninterrupted operation that the grate can maintain without stopping the furnace for maintenance. 3.2
Main air compartment
The air compartment of the main combustion zone.
Average air pressure for air compartment along grate widthpi
An index to measure the average air pressure performance of the grate longitudinal air compartment when there is no coal layer. 3.4
Average air pressure for air compartment
Average air pressure for air compartmentp
An index to measure the average air pressure performance of the grate air compartment when there is no coal layer. 3.5
Unevenness factor of air distribution across grate width1
JB/T3271—2002
An index to measure the uniformity of air volume distribution across grate. 3.6
Scale air ratio of air compartmentSi-n
An index to measure the airtightness performance of air leakage from the main air compartment to other air compartments. 3.7
Reserve air ratio of air compartmentB;
An index to measure the air tightness performance of main air compartment leakage. 3.8
Relative air ratio as air damper fully shut offM.
An index to measure the air tightness performance of air leakage when air damper is fully shut off. 4 Technical requirements
Basic performance of chain grate
The combustion efficiency of chain grate and the area heat load of chain grate shall meet the design requirements. 4.1.1
The continuous operation time of chain grate shall not be less than 4800h. 4.1.2
The qualified standard of cold test for chain grate mechanical transmission is: a) The chain, grate bar and grate sheet should move flexibly without any blocking, jamming, overturning or falling off. The grate surface should remain flat and the slag blocking device should be neatly attached to the grate surface. The grate should run flexibly and smoothly without deviation, arching, jamming or abnormal sound. b)
c) The temperature rise of the grate gearbox oil pool shall not exceed 35℃ and the bearing temperature shall not exceed 40℃. d) The current and temperature rise of the motor shall not exceed the rated value. The qualified standards for the cold performance test items of the chain grate air supply system are shown in Table 1, Table 2, Table 3 and Table 4. 4.1.4
Table 1 Grate lateral air distribution unevenness coefficient p
Wind chamber form
Air supply mode
Grate form
Indicator item
Indicator value%
Single wind chamber type
Double wind chamber type
Wind chamber average air pressure p
Chain belt type
Bucket type
Scale type
~300
Table 3 Wind retention rate B of wind chamber; and air leakage rate Si.mS -2
Note 1: The table takes five air chambers as an example, among which the third air chamber is the main air chamber. S3-3 (B3) a
12～15
Note 2: The table gives the wind retention rate of the third air chamber (main air chamber) and the wind penetration rate from the third air chamber to each air chamber, and S3-3-B3. a If the number of air chambers increases, the B of the main air chamber should still be maintained between 50% and 60%. 2
Front and rear air intake unified warehouse type
Unit: Pa
Beam type
Damper type
Table 4 Flow rate when the damper is fully closed (M.) Hinged baffle
Shutter type
Plane plug-in type
Two steel plates, one fixed and one movable, the movable steel plate can move up and down, left and right, or rotate. 4.2 Basic requirements for chain grate design
4.2.1 The design of chain grate shall comply with the relevant provisions of JB/T10094. 4.2.2 The design coal type of chain grate shall comply with the provisions of GB/T18342. JB/T 3271 ---2002
End plate type
4.2.3 The design of chain grate shall adopt advanced technology to make the product meet the requirements of safety, reliability, high efficiency, economy and environmental protection. 4.2.4 The design of chain grate shall be closely coordinated with the boiler body and furnace drying, and the factors such as grate manufacturing cost, boiler room construction and operation and maintenance costs shall be comprehensively considered.
4.2.5 Effective measures shall be taken in the design of chain grate to reduce the pollution caused by boiler operation to the environment. 4.2.6 The air supply system of chain grate shall have good sealing, air distribution and adjustment performance. 4.2.7 The design of chain grate shall ensure sufficient grate area. 4.2.8 The chain grate design should have a suitable ventilation section to meet the requirements of the coal type. 4.3 Manufacturing
4.3.1 The materials of the main structural components of the chain grate (guide rails, steel plate composite beams, steel composite beams and other components) should have quality certificates and be inspected and accepted in accordance with the provisions of JB/T3375. When there is no quality certificate or there is doubt about the quality certificate of the material, the material should be inspected by the factory according to the inspection items specified in the material product standards and (or) the order contract. Materials that fail the factory inspection are not allowed to be put into production. 4.3.2 The heat resistance, wear resistance and strength of the chain grate casting material should meet the use conditions, and its material should comply with the provisions of GB/T9437:'GB/T9439.
4.3.3 Alloy cast iron and cast steel should be inspected before the furnace, and the chemical composition and mechanical properties should meet the requirements of the corresponding standards. 4.3.4 Chain grate castings should be mechanically molded. For castings with a large number of parts such as grate plates, grate bars, rollers, chain links, splints, etc., mechanical molding should be used.
4.3.5 The sprocket should be mechanically molded with a metal mold to ensure casting accuracy. 4.3.6 The casting size tolerance, casting weight tolerance, and casting machining allowance should all comply with the requirements of the drawings. If the drawings indicate that they are in accordance with the provisions of GB/T6414, they should comply with the relevant tolerance grades in the indicated GB/T6414. 4.3.7 The casting surface should be flat, free of defects such as slag inclusions and cracks, and burrs, flash and pouring risers should be removed. The grate ventilation slots should comply with the requirements of the drawings. Grate bars and grate side seals (including side seal blocks, sealing straps, side grate bar splints and other parts) should be selected in batches to minimize their relative deviations. 4.3.8 The section edge deviation of the steel assembly △h (see Figure 1) shall not exceed 0.5mm when H≤300mm and shall not exceed 1mm when H>300mm.
Figure 1 Section edge deviation of steel assembly
4.3.9 The section height deviation of the steel plate assembly △h≤±2mm. 4.3.10 The length deviation of the beam ^L shall not exceed ±2mm when the length of the beam L≤5m and shall not exceed ±4mm when L>5m. The lateral curvature and deflection f of the beam shall not be greater than 1/1000 of its length and shall not exceed 5mm at most. 4.3.11
The steel plate used for the wall panel of the chain grate bracket shall not be uneven, otherwise it shall be carefully leveled. When the middle beam is made of steel, splicing is not allowed. 4.3.12
When a steel plate composite beam is used, the flange and web in the middle 1/3 of the beam shall not be spliced. When the rest of the parts are spliced, the splicing welds of the flange and web shall be staggered by more than 200mm, and there shall be a reinforcing plate at the web splicing. When the guide rail is made of steel, it shall be straight and no local bending is allowed. 3
JB/T 3271-2002
4.3.13 The dimensional deviation of the machined parts of the chain grate shall comply with the requirements of the drawing. If the dimensional deviation is not indicated on the drawing, its dimensional deviation shall not be lower than the IT9 grade in GB/T1800.3.
4.3.14 The inter-tooth deviation (front and rear misalignment of the tooth tip) between two adjacent sprockets on the same axis shall not exceed 2mm; the inter-tooth deviation between any two sprockets shall not exceed 2mm for beam grates and 4mm for scale grates. 4.3.15 The relative length difference of each chain on the same grate under the same tension state should not exceed 8mm. 4.4 Assembly
4.4.1 The manufacturer should prepare a detailed product installation manual, and the requirements of the installation manual should not be lower than this standard. 4.4.2 Before assembling the chain grate, the assembly unit should count all parts. If the wall panels, guide rails and other parts are deformed during transportation and storage, they should be leveled and straightened before assembly. 4.4.3 When assembling the chain grate, its longitudinal and lateral free expansion should be guaranteed. The lateral expansion direction of the driving shaft, driven shaft and grate should be consistent.
4.4.4 The height deviation of the corresponding points of the left and right bracket wall panels should not exceed 3mm (see Figure 2), and it should be checked at the front, middle and back points during the assembly process. The horizontal deviation of the front and rear axles should not be greater than 1/1000. 4.4.5 The span deviation △L between the left and right bracket wall panels (see Figure 2) shall not exceed 3mm when the span between the wall panels L≤5m, and shall not exceed 5mm when L5m. It can be measured at 3 locations: front, middle and back. L-AL
Support seat or wall panel seat
Figure 2 Wall panel installation deviation
4.4.6 The difference in the length of the diagonal lines on the left and right bracket wall panels (see Figure 3) shall not exceed 4mm when the distance between the left and right bracket wall panels is l≤5m, and shall not exceed 8mm when 1>5m.
Right wall panel upper cover
Rear axle centerline
Rear reference point
Left wall panel upper cover
Front axle centerline
Front reference point
Figure 3 Difference in length of diagonal lines on the planes of the bracket wall panels on both sides 4.4.7 The vertical deviation of the bracket wall panels should not exceed 3mm, and can be measured by hanging wires at the easy-to-measure positions at the front and rear ends. JB/T3271—2002
4.4.8 The upper guide rails of the scale chain grate should be on the same plane, the upper surface height deviation between two adjacent guide rails should not exceed 2mm, the upper surface height deviation between any two guide rails should not exceed 3mm, and the deviation △L of the spacing L between adjacent guide rails should not exceed 2mm (see Figure 4). L+AL
Figure 4 Guide rail height deviation and spacing deviation
4.4.9 The working surface of the friction plate on the support of the chain belt chain grate should be on the same plane, and its flatness deviation should not exceed 3mm, and the intersection should be flat and smooth.
4.4.10 The deviation of the distance a and b between each sprocket and the center point of the axis should not exceed 2mm (see Figure 5). ±2
Drive shaft
Axis center point
Figure 5 Distance between sprocket and axis center point
4.4.11 The height between the front beam, rear beam and middle beam of the crossbeam chain grate can be adjusted by the pad on the bracket, and the height deviation after adjustment Ah≤2mm (see Figure 6).
Figure 6 Height deviation of each beam of the crossbeam chain grate 4.4.12 The center line deviation of the upper and lower guide rails of the crossbeam chain grate 4≤1mm (see Figure 7). Daytime beamwww.bzxz.net
4.4.13 There should be enough expansion gap between the front and rear axles and the side plates of the bracket. For scale-type and cross-beam chain grates, the expansion gap should be marked on the design drawings.
4.4.14 If water cooling devices are used for bearings, coal gates, etc., the devices should be subjected to a water pressure test with a pressure of 0.4MPa. Those that do not leak after 2 minutes are qualified.
JB/T 3271—2002
Figure 7 Deviation of the center line of the upper and lower guide rails of the cross-beam chain grate4.4.15 The gap between the side sealing block and the grate plane should meet the requirements of the design drawings. The front and rear gaps should be evenly hooked to avoid both the grate being stuck and the air and coal leakage caused by too large a gap. 4.4.16 The joint between the coal hopper and the furnace wall should be tight. 4.4.17 The coal gate should be flexible to lift and lower, and the opening should meet the requirements of the design drawings. The difference in distance between the lower edge of the coal gate and the grate surface along the width direction should not exceed 5mm.
5 Inspection and testing
5.1 General requirements for inspection and testing
5.1.1 Each chain grate can be delivered to the user only after passing the inspection and test. The inspection and test items include the appearance and size inspection of the chain grate after assembly, the mechanical transmission cold test and the cold performance test of the air supply system. 5.1.2 The appearance and size inspection and mechanical transmission cold test after assembly should be carried out one by one. The first unit of new products and modified products should also be tested for the cold performance of the air supply system. When the cumulative production of the same model reaches 50 units or one unit is sampled every three years, the cold performance re-inspection of the air supply system should be carried out. The results of the test or re-inspection can represent the cold air supply performance of the product. 5.1.3 The inspection and test can be carried out in the manufacturer or at the user's site after the user installs it. 5.2 Appearance and size inspection
After the chain grate is assembled, the appearance and size inspection should be carried out. The grate surface should be flat, the gap between the grate pieces should be uniform, the gap between the side seals and the thermal expansion gap should meet the requirements of the drawings, and the opening of various dampers should be flexible. The relevant dimensions should meet the requirements of 4.3 and 4.4 of this standard. 5.3 Mechanical transmission cold test
5.3.1 The speed regulating device used in the mechanical transmission cold test shall be consistent with the product design requirements. 5.3.2 The time of the mechanical transmission cold test is: a) The test time for the chain belt type chain grate shall not be less than 4h; b) The test time for the scale type and beam type chain grate shall not be less than 8h. 5.3.3 The test run of the mechanical transmission cold test shall include high and low speeds, and each speed shall run for no less than 2 circles. If there are accidents such as deviation, arching, grate bar falling off, and grate chain breaking during the test run, the cause shall be found and eliminated in time, and the test time shall be recalculated after the fault is eliminated. 5.3.4 After the mechanical transmission cold test, those who meet the requirements of 4.1.3 of this standard are qualified. 5.4 Cold performance test of air supply system
5.4.1 The cold performance test method of the chain grate air supply system is shown in Appendix A. 5.4.2 The cold performance test of the chain grate air supply system should include the following items: a) The horizontal air distribution unevenness coefficient np of each air chamber grate: b) The flow rate Mo when the air door is fully closed;
c) The air retention rate B of the air chamber; and the air leakage rate Si-n; d) The average air pressure p of the air chamber
5.4.3 After the cold performance test of the air supply system, those that meet the requirements of 4.1.4 of this standard are qualified. 5.5 Inspection and test records
JB/T 3271---2002
For products that have passed the inspection and test, the results of the mechanical transmission cold test and the air supply system cold test should be listed in the boiler quality certificate or provided to the user in a separate document. 6 Paint packaging
Paint packaging should be carried out in accordance with JB/T1615 and the requirements of the drawings or order contracts. Transmission device accessories, vulnerable and easily lost parts should be packed and shipped. 6.21
6.3 Product manuals, installation manuals and other documents should be provided to users along with the product. JB/T3271—2002
A.1 Test bench
Appendix A
(Normative appendix)
Cold performance test method for chain grate air supply system The schematic diagram of the cold pneumatic test bench for the cold performance test of the chain grate air supply system is shown in Figure A.1. 2
—Motor: 4—-Soft connection section; 5-Air adjustment section; 6—Voltage stabilization section: 7—Contraction section;—Air collector: 2— Blower; 3—
8——Speed measurement section; 9———Pitot tube test seat: 10—Total air duct: 11——Test piece; 12—Air chamber damper Figure A.1 Schematic diagram of cold wind dynamic test bench
A.2 Layout of measuring points and corresponding instruments
A.2.1 Air flow
The total air flow can be calculated using the Pitot tube measurement value installed in the speed measurement section of the test bench, or it can be measured from the air collector in front of the blower. The air flow of each air chamber can be measured using a Pitot tube or a flute tube in the air duct at the inlet of the air chamber. A.2.2 Atmospheric pressure
Measured with a barometer.
A.2.3 Atmospheric temperature and air flow temperature
Measured with a laboratory glass thermometer.
A.2.4 Chamber pressure
The wind pressure distribution under the grate surface in the chamber can be measured by using a special bell-shaped pressure measuring seat and a micromanometer. The arrangement of the pressure measuring points on the grate surface is shown in Figure A.2. There are m rows arranged along the grate longitudinally and n rows arranged along the grate transversely, so the total number of pressure measuring points is m×n.
A.2.5 Temperature and pressure measuring points in the air duct
Relevant measuring points can be arranged in the main air duct, each branch air duct, each air chamber and air inlet as needed, such as the static pressure measuring points on the wall of the branch air duct at the inlet of each air chamber.
A.3 Test conditions
The total air flow of the test conditions shall be carried out according to the rated conditions of the boiler design. The air flow of the main air chamber is recommended to be 30% to 40% of the total air flow. A.4 Arrangement of test data and calculation formula
A.4.1 Average wind pressure P in wind chamber row
(m rows)
4-330)
A/8 4/4 1 A/4 / A/4 14R
B(-365)
B/31B/6
Figure A.2 Schematic diagram of measurement point arrangement on grate
C(=365)
(n examples)
JB/T 3271---2002
The wind chamber pressure measuring points are arranged in m rows (=1, 2, 3, 4,, m), and each row has n columns of measuring points (j=1, 2, 3, 4,, n). The calculation formula for the average wind pressure p of the wind chamber in all m rows (i.e. the average wind pressure of the wind chamber row) is: 1
Where:
-the measured value of the wind chamber pressure in the row in the row, in Pa. A.4.2 Average wind pressure p of the wind chamber
The average wind pressure P of the wind chamber is the average wind pressure measured at all measuring points in the wind chamber, and its calculation formula is: III
A.4.3 Grate lateral air distribution unevenness coefficient np The calculation formula for the grate lateral air distribution unevenness coefficient IIp is: p
Where:
-the maximum value of the average wind pressure of the wind chamber row, in Pa; -the minimum value of the average wind pressure of the wind chamber row, in Pa. Pjmin1 Test bench
Appendix A
(Normative appendix)
Test method for cold performance of chain grate air supply system The schematic diagram of the cold pneumatic test bench for the cold performance test of the chain grate air supply system is shown in Figure A.1. 2
—Motor: 4—-Soft connection section; 5-Air adjustment section; 6—Voltage stabilizing section: 7—Contraction section; —Air collector: 2—Blower; 3—
8—Speed measurement section; 9——Pitot tube measuring seat: 10—Main air duct: 11—Test piece; 12—Air chamber air regulating door Figure A.1 Schematic diagram of cold pneumatic test bench
A.2 Arrangement of measuring points and corresponding instruments
A.2.1 Air flow
The total air flow can be calculated using the value measured by the Pitot tube installed in the speed measurement section of the test bench, or it can be measured from the air collector in front of the blower. The air flow rate of each wind chamber can be measured by using a pitot tube or a flute tube in the wind duct at the wind chamber inlet. A.2.2 Atmospheric pressure
Measured by a barometer.
A.2.3 Atmospheric temperature and air flow temperature
Measured by a laboratory glass thermometer.
A.2.4 Wind chamber pressure
Measured by a special bell-shaped pressure measuring seat and a micromanometer, the wind pressure distribution under the grate surface in the wind chamber can be measured. The arrangement of pressure measuring points on the grate surface is shown in Figure A.2. There are m rows arranged along the grate longitudinally and n rows arranged along the grate transversely, so the total number of pressure measuring points is m×n.
A.2.5 Temperature and pressure measuring points in the air duct
Relevant measuring points can be arranged in the main air duct, each branch air duct, each wind chamber and air inlet as needed, such as the static pressure measuring points on the wall of the branch air duct at the inlet of each wind chamber.
A.3 Test conditions
The total air flow rate of the test conditions shall be based on the rated conditions of the boiler design. The air flow rate of the main air chamber is recommended to be 30% to 40% of the total air flow rate. A.4 Test data collation and calculation formula
A.4.1 Average air pressure P of air chamber row
(m rows)
4-330)
A/8 4/4 1 A/4 / A/4 14R
B(-365)
B/31B/6
Figure A.2 Schematic diagram of the arrangement of measuring points on the grate
C(=365)
(n cases)
JB/T 3271---2002
The wind chamber pressure measuring points are arranged in m rows (=1, 2, 3, 4,, m), and each row has n columns of measuring points (j=1, 2, 3, 4,, n). The calculation formula for the average wind pressure p of the wind chamber in all m rows (i.e. the average wind pressure of the wind chamber row) is: 1
Where:
-the measured value of the wind chamber pressure in the row in the row, in Pa. A.4.2 Average wind pressure p of the wind chamber
The average wind pressure P of the wind chamber is the average wind pressure measured at all measuring points in the wind chamber, and its calculation formula is: III
A.4.3 Grate lateral air distribution unevenness coefficient np The calculation formula for the grate lateral air distribution unevenness coefficient IIp is: p
Where:
-the maximum value of the average wind pressure of the wind chamber row, in Pa; -the minimum value of the average wind pressure of the wind chamber row, in Pa. Pjmin1 Test bench
Appendix A
(Normative appendix)
Test method for cold performance of chain grate air supply system The schematic diagram of the cold pneumatic test bench for the cold performance test of the chain grate air supply system is shown in Figure A.1. 2
—Motor: 4—-Soft connection section; 5-Air adjustment section; 6—Voltage stabilizing section: 7—Contraction section; —Air collector: 2—Blower; 3—
8—Speed measurement section; 9——Pitot tube measuring seat: 10—Main air duct: 11—Test piece; 12—Air chamber air regulating door Figure A.1 Schematic diagram of cold pneumatic test bench
A.2 Arrangement of measuring points and corresponding instruments
A.2.1 Air flow
The total air flow can be calculated using the value measured by the Pitot tube installed in the speed measurement section of the test bench, or it can be measured from the air collector in front of the blower. The air flow rate of each wind chamber can be measured by using a pitot tube or a flute tube in the wind duct at the wind chamber inlet. A.2.2 Atmospheric pressure
Measured by a barometer.
A.2.3 Atmospheric temperature and air flow temperature
Measured by a laboratory glass thermometer.
A.2.4 Wind chamber pressure
Measured by a special bell-shaped pressure measuring seat and a micromanometer, the wind pressure distribution under the grate surface in the wind chamber can be measured. The arrangement of pressure measuring points on the grate surface is shown in Figure A.2. There are m rows arranged along the grate longitudinally and n rows arranged along the grate transversely, so the total number of pressure measuring points is m×n.
A.2.5 Temperature and pressure measuring points in the air duct
Relevant measuring points can be arranged in the main air duct, each branch air duct, each wind chamber and air inlet as needed, such as the static pressure measuring points on the wall of the branch air duct at the inlet of each wind chamber.
A.3 Test conditions
The total air flow rate of the test conditions shall be based on the rated conditions of the boiler design. The air flow rate of the main air chamber is recommended to be 30% to 40% of the total air flow rate. A.4 Test data collation and calculation formula
A.4.1 Average air pressure P of air chamber row
(m rows)
4-330)
A/8 4/4 1 A/4 / A/4 14R
B(-365)
B/31B/6
Figure A.2 Schematic diagram of the arrangement of measuring points on the grate
C(=365)
(n cases)
JB/T 3271---2002
The wind chamber pressure measuring points are arranged in m rows (=1, 2, 3, 4,, m), and each row has n columns of measuring points (j=1, 2, 3, 4,, n). The calculation formula for the average wind pressure p of the wind chamber in all m rows (i.e. the average wind pressure of the wind chamber row) is: 1
Where:
-the measured value of the wind chamber pressure in the row in the row, in Pa. A.4.2 Average wind pressure p of the wind chamber
The average wind pressure P of the wind chamber is the average wind pressure measured at all measuring points in the wind chamber, and its calculation formula is: III
A.4.3 Grate lateral air distribution unevenness coefficient np The calculation formula for the grate lateral air distribution unevenness coefficient IIp is: p
Where:
-the maximum value of the average wind pressure of the wind chamber row, in Pa; -the minimum value of the average wind pressure of the wind chamber row, in Pa. Pjmin
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