Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T 6736-93
Guidelines for Design of Boiler Steel Frame
Published on August 21, 1993
Published by the Ministry of Machinery Industry of the People's Republic of China and implemented on October 1, 1993
Subject Content and Scope of Application
Cited Standardswww.bzxz.net
Main Symbols
Basic Provisions
Design Provisions
Material and Strength Design Values
Frame Layout
Frame Classification
Layout Principles·
Component Layout Placement·
Load statistics and distribution·
Load classification and value provisions:
Load effect combination:
Load statistics:
Load distribution
Static analysis·
Simplified calculation diagram of the frame·
Horizontal support
Simplification of the simplified calculation diagram of the frame
Utilization of symmetry
Manual calculation Selection of framework analysis method·
Design and calculation of beams
Beam cross section
Beam strength calculation
Overall stability of beams
Local stability of beams
Torsion calculation of beams
Construction requirements of beams
Design and calculation of columns
Cross-section of columns
Slenderness ratio of columns
Calculation of columns
Calculation of tie materials for two-legged lattice columns
Calculation of weld seams on column shafts
Local stability
Calculation of column heads
Calculation of column bases
......
(4)
11.9 Structure Construction requirements
12 Truss design and calculation
12.1 Cross-sectional form of truss members
Truss member calculation
Vertical truss calculation
Furnace top beam lattice support system
Horizontal truss
Construction requirements
Connection design
Weld connection
High-strength bolt connection
Node design
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E| |tt||Appendix F
Appendix G
Appendix H
Appendix 1
Appendix
Appendix K
Appendix L
Appendix M
Appendix N
Appendix 0
Appendix P
Appendix Q
Appendix R
Appendix S
Appendix T
Appendix U
Appendix V
Appendix W
Appendix X
Steel Properties (Insulation Certificate items) (supplement) Steel pipe and water density table (supplement)
Insulation material and accessories weight table (supplement) Maximum allowable height of light furnace wall guard (supplement) Common cross-section mechanical properties (supplement)
Single-span beam calculation formula (supplement)
Conversion of single-span simply supported beam mid-span concentrated force (supplement) ... Variable section beam deflection calculation formula (supplement) Shape constants of several basic rods (supplement) ... Continuous beam calculation (supplement)
Single-layer frame calculation chart (supplement) ||tt| |Overall stability coefficient of beam (supplement)
Calculation of local stability of beam web (supplement)Calculation length coefficient of column (supplement)
Stability coefficient of axially compressed member (supplement).Relationship curve between spring coefficient of multi-elastic support column support and μ value of column calculation length coefficient (supplement).Design value of local compressive strength of concrete (supplement)Selection table of Q235 steel and 16Mn steel bolts (supplement)International steel specifications (supplement)
Combined section characteristics of members (supplement)Ground foundation intensity of major cities in China Degrees and basic ground intensity classification (reference) Outdoor meteorological parameters in various regions of the country (reference) Truss static analysis (hand calculation) (reference)
Frame static analysis (hand calculation) (reference) (54)
: (132)
(135)
: (139)
(142)
(142)
(145)
Machinery Industry Standard of the People's Republic of China
Guidelines for the Design of Boiler Steel Structures
JB/T 6736—93
This standard is formulated to implement the national technical and economic policies in the design of boiler steel structures, so that the boiler structure design can be safe, reliable, technologically advanced and economically reasonable while meeting the requirements of boiler equipment. 1
Subject content and scope of application
This standard proposes the principles and regulations for the design layout and material selection of the frame, and provides methods for load statistics and distribution, structural force analysis, and design calculation of components and connections.
This standard applies to the design of supported and suspended boiler frames and other similar equipment steel structures. 2 Reference standards
Technical conditions for high-quality carbon structural steel
Carbon structural steel
Hot-rolled I-beams
Hot-rolled ordinary channel steel
Basic types of weld grooves for gas welding, manual arc welding and gas shielded welding Basic types and sizes of weld grooves for submerged arc welding GB1228~1231 High-strength large hexagonal head bolts, large hexagonal nuts, washers for steel structures, sizes and technical conditions GB1300
GB1591
GB3077
GB3632
GB3633
GB5117
GB5118
GB5293
GB9787
GB9788
GB11352
ZB5339
3Main symbols
Steel wire for welding
Low Alloy structural steel
Technical conditions for alloy structural steel
Type and size of torsion shear type high-strength bolt connection for steel structure
Carbon steel welding rod for torsion shear type high-strength bolt connection for steel structure
Low alloy steel welding rod
Flux for submerged arc welding of carbon steel
Technical conditions
Dimensions, shape, weight and allowable deviation of hot-rolled equal-leg angle steelDimensions, weight and allowable deviation of hot-rolled unequal-leg angle steelGeneral engineering use Cast carbon steel
Building structure load code
Building seismic design code
Steel structure design code
Uniform standard for building structure design
Hot-rolled light I-beam
Hot-rolled light channel steel
Boiler seismic design standard
Action and effect
Approved by the Ministry of Machinery Industry on August 21, 1993
Implementation on October 1, 1993||t t||-Bending and torsion double moment:
Concentrated load:
Bending moment;
Free torsion moment;
Axial force;
JB/T6736-93
Pretension of high-strength bolts, recoil force of safety valves; Uniformly distributed load density;
Support reaction force;
Design value of load effect combination;
Standard value of horizontal earthquake effect;
Active Standard value of load effect;
Standard value of permanent load (constant load) effect; Standard value of wind load effect;
Deflection of beam;
Shear force;
Standard value of wind load;
-Basic wind pressure;
3.2. Calculation index
Elastic modulus of steel,
Design value of tensile, compressive and flexural strength of steel; Design value of axial compressive strength of concrete; fee|| tt||The design value of the end bearing strength of steel;
nong——the design value of the local bearing strength of concrete; li,,rui——the design value of the tensile, shear and compressive strength of high-strength bolts; f,,——the design value of the tensile, shear and compressive strength of butt welds; f
——the design value of the shear strength of steel;
——the design value of the tensile, shear and compressive strength of fillet welds; the yield strength (or yield point) of steel; the shear modulus of steel Quantity;
Euler critical force;
N, N, N-design value of tensile, shear and compressive bearing capacity of each high-strength bolt; normal stress,
local compressive stress:
stress perpendicular to the length direction of the fillet weld, calculated according to the effective section; shear stress
shear stress along the length direction of the fillet weld:
-free torsion shear stress;
[U]——allowable deflection of the beam;
3.3 Geometric parameters
Gross cross-sectional area;
A end face pressure bearing area;
Effective area;
Compression flange cross-sectional area;
Net cross-sectional area;
Pitch,
Width;
b, br?
JB/T 6736—93
Flange width or free overhang width of plate; Width of flange plate between webs of box section; Overhang width of stiffening rib;
Diameter;
Effective diameter;
Aperture;
Height;
Full height of section;
Effective thickness of fillet weld;
Foot size of fillet weld;
Calculated height of web;
Beam Economic height;
web height;
gross section moment of inertia;
net section moment of inertia;
sector moment of inertia;
section radius of gyration;
length or span;
calculated length:
calculated length of weld;
the assumed distribution length of a concentrated load on the edge of the web calculation height; gross section area moment;
the thickness of a plate and the furnace wall Thickness;
Thickness of stiffening ribs;
Thickness of web;
Resistance moment of gross section;
Resistance moment of net section;
Angle:
—Slenderness ratio:
In—Converted slenderness ratio;
Maximum sector area;
3.4 Calculation coefficient and others
Ci, C2—Dimensional parameters used to calculate the local stability of the web of the beam; Number of bolts;|| tt||The number of high-strength bolts on a calculated section; the number of force transmission friction surfaces of high-strength bolts, the number of shear surfaces of bolts;
Structural importance coefficient;
A frame natural vibration period;
Linear expansion coefficient;
Stress distribution unevenness coefficient of column web; Beam web planing and tightening coefficient;
-Wind vibration coefficient;
Equivalent bending moment coefficient of overall stability of beam;
JB/T 6736—93
- Strength design value increase factor of front fillet weld;,
- Equivalent bending moment coefficient of stability of compression-bending member; Wind vibration coefficient at Z height;
Strength design value increase factor of converted stress; Influence coefficient of bending normal stress on local stability of beam web; Influence coefficient of asymmetric beam section;
Anti-slip coefficient of friction surface of high-strength bolt; Calculated length coefficient of column; Wind load shape coefficient;
Wind pressure height variation coefficient;
Pulsation influence coefficient;
|Parameters used to calculate the overall stability of the beam; pulsation increase coefficient; width-to-thickness ratio of the web compression plate section of the beam;
stability coefficient of axially compressed members;
overall stability coefficient of the beam;
mode coefficient;
concentrated load increase coefficient;
combination coefficient of variable loads;
w—combination coefficient of wind loads;
A:
4 Basic regulations
The design frame must be closely coordinated with the requirements of the boiler body, auxiliary equipment, plant layout, transportation and installation. It must be ensured that the frame has sufficient strength, rigidity and stability during the operation, installation and maintenance of the boiler. 4.2
For frames requiring earthquake resistance, unless otherwise required, the earthquake resistance design of the frame shall be in accordance with ZB5339 standard. 4.31
Domestic materials should be used as much as possible to reduce the variety and specifications of materials. 4.4
Under the conditions of transportation, the design of the frame should expand the assembly as much as possible. 4.5
Except for special requirements, the design of the frame does not consider directly bearing dynamic loads. 4.6
When arranging the frame, the components should be kept away from high temperature (above 150℃) as much as possible. For components that must be arranged in the flue or exposed to high temperature for a long time, in addition to selecting suitable steel materials, necessary insulation or cooling measures should be taken. When applying the above-mentioned reference standards, the particularity of the boiler frame that is different from other general building structures should be fully considered. 4.8
5 Design regulations
5.1 This standard adopts the limit state design method and designs the frame according to the ultimate state of bearing capacity and the limit state of normal use. 5.2 When calculating the strength, stability and connection strength of the structure or component, the load design value should be used; when calculating the deformation, the load standard value should be used.
5.3 The relative horizontal displacement allowed by the frame shall be adopted in accordance with the provisions of Table 1: 5.4
Load category
Permanent load
Wind load
Ground action
JB/T6736-93
The ratio of the horizontal displacement between each layer and the top of the frame to the layer height or total height 500
Should not be greater than 50
The relative uneven settlement of the foundation should not be greater than two-tenths of the distance between adjacent columns. Unless otherwise specified, the structural importance coefficient is generally taken as 1.0. 5.5
5.6When considering the combination of seismic actions, the design value of the member material strength is increased by 25%. 6 Material and Strength Design Value
6.1 Material
The grades and standards of commonly used steel for boiler frame are shown in Table 26.1.1
Carbon structural steel
Low alloy structural steel
Casting carbon steel
Material grade
ZG230--450
ZG270-500
Quality standard
GB1591
GG11352
According to the use requirements, boiling steel or killed steel can be selected. The selection of welding materials should ensure that the weld metal has mechanical properties not lower than that of the basic metal. The welding materials can be selected according to Table 3. Table 3·
Basic metal
Q235 or
(Q235 and 16Mn)
Manual welding
E43××
E50××
GB5117
Automatic welding
H08MnA
H10Mn2
GB1300
Automatic welding
GB5293
GB5118
The high-strength bolted connection pairs used for connection shall meet the requirements of GB1228~1231 or GB3632~3633 standards. Their performance grades and the steels recommended in 6.1.4
are shown in Table 4.
HRC35~45
For the specifications and standards of commonly used steel, see Table 5
Recommended materials
20MnTiB
45, 35
45, 35
Material standards
GB3077
Used specifications
I-beam
JB/T 6736—93
GB9787
GB9788
6.1..6 Load-bearing structural steel
6.1.6.1 The mechanical properties and chemical composition of load-bearing structural steel must have a qualified guarantee that they meet the standards. If necessary, they should also have a qualified guarantee for cold bending tests.
6.1.6.2 The main load-bearing components with a calculated temperature equal to or lower than -20°C should not use boiling steel. 6.1.6.3 When the plate thickness or steel section thickness of the main load-bearing components is greater than 40mm, the raw materials should be supplied in the normalized state. 6.1.6.4 For thick plates of main load-bearing components arranged outdoors and in extremely cold areas, if there are no effective protective measures, the non-plastic transition temperature (NDT) of the steel should be lower than the lowest temperature that may occur during use. 6.1.7 Selection of component materials
6.1.7.1· In load-bearing components and connections, steel plates and angle steels with a thickness of less than 5mm, and steel pipes with a thickness of less than 3mm should not be used. 6.1.7.2 Component materials should be selected according to Table 6 based on the importance of the component, load characteristics, connection methods, calculation temperature and other different situations. Table 6
Component name
Main beams and beams with a beam height ≥ 2m
&. Tension flange
b. Carbon structural steel with flange thickness t≥40mmc.Low alloy structural steel general beams, columns and supports with flange thickness t≥36mm
Non-load bearing components
Main beam support
Material grade
Calculation temperature
>-20℃
≤-20℃
>-20℃
Q235--B
Q235-D
Q235-A
Q235-A·F
Q235-A·F
Q215-A
Q235-A
ZG230—450
ZG270-—500
Steel guarantee items
Tensile strength, yield point, elongation, cold bending, room temperature impact, carbon, sulfur and phosphorus content
Same as above. Q235 steel should have a qualified guarantee of 20℃ impact toughness: 16Mn steel should have a qualified guarantee of 40℃ impact toughness
Tensile strength, yield point, elongation, carbon, sulfur, phosphorus content
Carbon, sulfur, phosphorus content
Tensile strength, yield point, elongation, carbon, sulfur, phosphorus content
Note: The calculation temperature should be determined according to the outdoor calculation temperature of winter air conditioning specified in the current national "Heating, Ventilation and Air Conditioning Design Code" (Appendix V) For indoor boilers, it can be increased by 10℃ according to this regulation. 6.1.8
Material substitution
Among the items guaranteed by the mechanical properties of steel, Substitution provisions when only one item fails: 6.1.8.1
Elongation is within 3% lower than the value specified in the standard, which is allowed to be used; the service point is within 5% lower than the value specified in the standard, and its strength design value can be reduced according to the yield point ratio; impact toughness is not allowed to be reduced;
Substitution provisions when material specifications do not meet the requirements of the drawings: 6.1.8.2
The chemical composition and mechanical properties of the substitute material should be consistent with the original design drawings or the same level; a.
Detailed review of the strength, stiffness and stability of the component. When different materials are used as substitutes, corresponding changes need to be made to the fusion welding metal material. Strength design value
JB/T 6736-93
The strength design value of steel shall be adopted according to Table 7 based on the thickness or diameter of the steel, and the strength design value of steel castings shall be adopted according to Table 8. 6.2.1
The strength design value of welds and bolted connections shall be adopted according to Tables 9 and 10. 6.2.2
ZG200—400
ZG230-—450
ZG270—500||tt| |ZG310—570
Welding method
Electrode type
Automatic welding, semi-automatic welding and
with E43×× type welding rod
Manual welding
Automatic welding, semi-automatic welding and
with E50×× type welding rod
Thickness or diameter
>16~40
>40～6 0
>60～100
>100~150
17～25
26～36
55~100
Tensile, compression, bending
Tensile, compression and bending
Shear
Strength design value of steel castings
Shear
Strength design value of welds||tt| |Component steel
Thickness or diameter
>16~40
>40~60
>60~100
>100~150
55~100
Butt weld
When the weld quality is of the following levels
tensile and bending resistance
First level, second level
End face bearing pressure (planed and tightened).
End face bearing pressure (planed and tightened) f.
Tensile, bending
and shear
Material grade of bolts
(or performance grade)
and material number of components
Pressure-bearing high-strength bolts
Component steel
JB/T6736—93
Strength design value of bolt connection
Ordinary bolts
Grade C bolts
Note: Holes with wall quality that is inferior to the following are classified as Class 1 holes: Shear
① On assembled components Holes drilled according to the designed aperture; pressure
Grade A and B bolts
(Type 1 hole)
(Type 1 hole)
Pressure-bearing high-strength bolts
② Holes drilled on individual parts and components according to the designed aperture using a drill template; ③ First drill or punch a smaller aperture on an individual part, and then expand the aperture to the designed aperture on the assembled component, pressure-bearing
6.2.3 The design strength value of angle steel connected on one side and high-altitude installation welds with poor construction conditions should be multiplied by the corresponding reduction factor, and the reduction factor shall be adopted according to Table 11.
Table 11 Strength design value reduction factor
Structural member or connection condition
Strength and connection calculated based on axial force
Equal angle steel
Single angle steel connected on one side
Stability calculated based on axial pressure
High-altitude installation welds with poor construction conditions
Unequal angle steel connected on short sides
Unequal angle steel connected on long sides Angle steel
Reduction coefficient
0.06+0.0015
and ≤1.0
0.5+0.0025)
and ≤1.0
Note: ①In is the slenderness ratio. For single angle steel pressure bar without connection in the middle, it should be calculated according to the minimum turning radius; when In<20, take In=20②When several situations exist at the same time, the reduction coefficient should be multiplied. The physical properties and temperature effects of steel and steel castings shall be adopted according to Table 12 and Table 13. 6.2.4
7 Frame arrangement
7.1 Frame classification
Frame-type frame (Figure 1) is generally used for medium and small capacity boilers, and the components are connected by flexible connections; truss-type frame (Figure 2) is generally used for large capacity suspended boilers, and the components are connected by hinged or rigid connections; hybrid frame (Figure 3) is generally used for medium and small capacity boilers with the furnace chamber partially suspended and the rear heating surface partially supported, and the frame is composed of frame type and truss type.2
ZG200—400
ZG230-—450
ZG270—500
ZG310—570
Welding method
Electrode type
Automatic welding, semi-automatic welding and
with E43×× type welding rod
Manual welding
Automatic welding, semi-automatic welding and
with E50×× type welding rod
Manual welding
Thickness or diameter
>16~40
>40～60
>60～100
>100~150
17～25
2 6～36
55~100
Tensile, compression, bending
Tensile, compression and bending
Shear f
Strength design value of steel castings
Shear f,
Strength design value of welds
Component steel
Thickness or diameter
>16~40
>40~60
>60~100
>100~150
55~100
Butt welds
When the weld quality is the following levels, tensile and bending
First level, second level
End face bearing pressure (planed and tightened).
End face bearing pressure (planed and tightened) f.
Tensile, bending
and shear
Material grade of bolts
(or performance grade)
and material number of components
Pressure-bearing high-strength bolts
Component steel
JB/T6736—93
Strength design value of bolt connection
Ordinary bolts
Grade C bolts
Note: Holes with wall quality that is inferior to the following are classified as Class 1 holes: Shear
① On assembled components Holes drilled according to the designed aperture; pressure
Grade A and B bolts
(Type 1 hole)
(Type 1 hole)
Pressure-bearing high-strength bolts
② Holes drilled on individual parts and components according to the designed aperture using a drill template; ③ First drill or punch a smaller aperture on an individual part, and then expand the aperture to the designed aperture on the assembled component, pressure-bearing
6.2.3 The design strength value of angle steel connected on one side and high-altitude installation welds with poor construction conditions should be multiplied by the corresponding reduction factor, and the reduction factor shall be adopted according to Table 11.
Table 11 Strength design value reduction factor
Structural member or connection condition
Strength and connection calculated based on axial force
Equal angle steel
Single angle steel connected on one side
Stability calculated based on axial pressure
High-altitude installation welds with poor construction conditions
Unequal angle steel connected on short sides
Unequal angle steel connected on long sides Angle steel
Reduction coefficient
0.06+0.0015
and ≤1.0
0.5+0.0025)
and ≤1.0
Note: ①In is the slenderness ratio. For single angle steel pressure bar without connection in the middle, it should be calculated according to the minimum turning radius; when In<20, take In=20②When several situations exist at the same time, the reduction coefficient should be multiplied. The physical properties and temperature effects of steel and steel castings shall be adopted according to Table 12 and Table 13. 6.2.4
7 Frame arrangement
7.1 Frame classification
Frame-type frame (Figure 1) is generally used for medium and small capacity boilers, and the components are connected by flexible connections; truss-type frame (Figure 2) is generally used for large capacity suspended boilers, and the components are connected by hinged connections or rigid connections; mixed-type frame (Figure 3) is generally used for medium and small capacity boilers with the furnace chamber partially suspended and the rear heating surface partially supported, and the frame is composed of frame type and truss type.2
ZG200—400
ZG230-—450
ZG270—500
ZG310—570
Welding method
Electrode type
Automatic welding, semi-automatic welding and
with E43×× type welding rod
Manual welding
Automatic welding, semi-automatic welding and
with E50×× type welding rod
Manual welding
Thickness or diameter
>16~40
>40～60
>60～100
>100~150
17～25
2 6～36
55~100
Tensile, compression, bending
Tensile, compression and bending
Shear f
Strength design value of steel castings
Shear f,
Strength design value of welds
Component steel
Thickness or diameter
>16~40
>40~60
>60~100
>100~150
55~100
Butt welds
When the weld quality is the following levels, tensile and bending
First level, second level
End face bearing pressure (planed and tightened).
End face bearing pressure (planed and tightened) f.
Tensile, bending
and shear
Material grade of bolts
(or performance grade)
and material number of components
Pressure-bearing high-strength bolts
Component steel
JB/T6736—93
Strength design value of bolt connection
Ordinary bolts
Grade C bolts
Note: Holes with wall quality that is inferior to the following are classified as Class 1 holes: Shear
① On assembled components Holes drilled according to the designed aperture; pressure
Grade A and B bolts
(Type 1 hole)
(Type 1 hole)
Pressure-bearing high-strength bolts
② Holes drilled on individual parts and components according to the designed aperture using a drill template; ③ First drill or punch a smaller aperture on an individual part, and then expand the aperture to the designed aperture on the assembled component, pressure-bearing
6.2.3 The design strength value of angle steel connected on one side and high-altitude installation welds with poor construction conditions should be multiplied by the corresponding reduction factor, and the reduction factor shall be adopted according to Table 11.
Table 11 Strength design value reduction factor
Structural member or connection condition
Strength and connection calculated based on axial force
Equal angle steel
Single angle steel connected on one side
Stability calculated based on axial pressure
High-altitude installation welds with poor construction conditions
Unequal angle steel connected on short sides
Unequal angle steel connected on long sides Angle steel
Reduction coefficient
0.06+0.0015
and ≤1.0
0.5+0.0025)
and ≤1.0
Note: ①In is the slenderness ratio. For single angle steel pressure bar without connection in the middle, it should be calculated according to the minimum turning radius; when In<20, take In=20②When several situations exist at the same time, the reduction coefficient should be multiplied. The physical properties and temperature effects of steel and steel castings shall be adopted according to Table 12 and Table 13. 6.2.4
7 Frame arrangement
7.1 Frame classification
Frame-type frame (Figure 1) is generally used for medium and small capacity boilers, and the components are connected by flexible connections; truss-type frame (Figure 2) is generally used for large capacity suspended boilers, and the components are connected by hinged or rigid connections; hybrid frame (Figure 3) is generally used for medium and small capacity boilers with the furnace chamber partially suspended and the rear heating surface partially supported, and the frame is composed of frame type and truss type.
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