1 Scope
This part of GB/T 16508 specifies the design and structural requirements for basic pressure parts of shell boilers, and provides the basic design requirements for cast-iron boiler (Appendix A), rectangular header (Appendix B) and water tube plate (Appendix C).
This part is applicable to the design calculation for cylindrical parts subject to internal and external pressures, heads, tube plates, tension braces and foot rings as well as opening and reinforcement.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB/T 1576 Water Quality for Industrial Boilers
GB/T 2900.48 Electrotechnical Terminology of Boilers
GB/T 9252 Method for Cycling Test of Gas Cylinders
GB/T 12145 Quality Criterion of Water and Steam for Generating Unit and Steam Power Equipment
GB 13271 Emission Standard of Air Pollutants for Boiler
GB/T 16508.1-2013 Shell Boilers - Part 1: General Requirements
GB/T 16508.2 Shell Boilers - Part 2: Material
GB/T 16508.4 Shell Boilers - Part 4: Fabrication, Inspection and Acceptance
NB/T 47013
(JB/T 4730) Nondestructive Testing of Pressure Equipment
TSG G0001 Boiler Safety Technical Supervision Administration Regulation
TSG G0002 Supervision Administration Regulation on Energy Conservation Technology for Boiler
3 Terms and Definitions
For the purposes of this document, the terms and definitions established in GB/T 16508.1 and GB/T 2900.48 apply.
4 Symbols and Units
Meanings and units of the symbols used in chapters and sections of this part are as follows:
Et - the elasticity modulus of material upon temperature calculation, MPa;
p - the calculating pressure, MPa;
[p] - the maximum permissible operating pressure upon verifying calculation, MPa;
pr - the rated pressure of boiler, MPa;
p0 - the operating pressure, MPa;
ts - the saturation temperature of medium corresponding to the calculating pressure (the nominal outlet temperature of hot water boiler), ℃;
tc - the calculating temperature, ℃;
tmave - the rated average temperature of medium, ℃;
Δpa - the design additional pressure (the set pressure of relief valve), MPa;
Δph - the liquid column static pressure borne by pressure part, MPa;
Δpf - the additional pressure of dynamic resistance of medium flow, MPa;
η - the correction coefficient;
[σ]J - the permissible stress, MPa.
5 Basic Requirements for Design
5.1 Structural requirements
5.1.1 The boiler design shall comply with safety technical codes like "Boiler Safety Technical Supervision Administration Regulation" (TSG G0001) and "Supervision Administration Regulation on Energy Conservation Technology for Boiler" (TSG G0002); moreover, advanced technologies shall be adopted to make the product meet the requirements of safety, reliably, high efficiency, economy and environmental protection.
5.1.2 The calculating load to be considered and the load calculation to be carried out are determined according to the requirements of this part. The minimum required thickness of pressure part is determined according to relevant strength calculation formulas, stress analysis calculation formulas and requirements in this part.
Where the strength of boiler pressure part is determined through test or other calculation method, relevant technical information and scheme as well as conditions and data of the test carried out shall be submitted to the Special Equipment Safety Technical Committee of General Administration of Quality Supervision, after evaluation by which, shall be submitted to the General Administration of Quality Supervision for approval; then trial fabrication and trial use may be carried out.
5.1.3 Wall thickness and length of shell and boiler furnace
5.1.3.1 Where the inside diameter of shell is greater than 1000mm, the wall thickness selected for shell shall not be less than 6mm; where the inside diameter of shell is not greater than 1000mm, the wall thickness selected for shell shall not be less than 4mm.
5.1.3.2 The inside diameter of boiler furnace shall not exceed 1800mm, and its wall thickness selected shall not be less than 8mm and not greater than 22mm; where the inside diameter of boiler furnace is less than or equal to 400mm, its wall thickness selected shall not be less than 6mm; for the reversal chamber of horizontal internal combustion boiler, the selected wall thickness of its shell shall not be less than 10mm and not greater than 35mm.
5.1.3.3 The wall thickness selected for the shell and tube plate in expansion connection shall not be less than 12mm. Structural design of expansion connection shall not be adopted for the tube with outside diameter greater than 89mm.
5.1.3.4 The calculating length of the plain boiler furnace of the horizontal shell boiler shall not exceed 2000mm; where butt connection is adopted for boiler furnace ends and tube plate flange, the calculating length of the plain boiler furnace may be increased to 3000mm.
5.1.4 The lowest safe water level of the steam boiler shall be 100mm higher than the highest fire line; however, for the horizontal shell boiler with the inside diameter not greater than 1500mm, the lowest safe water level shall be 75 mm higher than the highest fire line. The minimum and maximum safe water level of the boiler shall be indicated in the drawing.
5.1.5 The structural type of pressure component (part) as well as the arrangement of openings and welds shall avoid or reduce the combined stress and stress concentration as possible. The adopted weld type shall comply with the design document and GB/T 16508.4. The weld subject to non-destructive testing shall be designed as the type for which the required non-destructive testing may be carried out.
5.1.6 Full-penetration butt joint shall be adopted for main weld of the main pressure part for the boiler (e.g. longitudinal and circumferential welds of shell, boiler furnace, reversal chamber and header, as well as butt welds of head, tube plate, boiler furnace top and foot ring); overlapped structure shall not be adopted for the weld of boiler pressure part; splicing shall not be adopted for tension brace.
5.1.7 Where the inside diameter of shell is greater than 1000mm, man-hole shall be arranged on the shell or head (tube plate); where personnel cannot enter into the boiler due to structural constraint, only inspection hole may be arranged; for the boiler with smoke tube arranged in shell, the arrangement of man-hole and inspection hole shall give consideration to the overhaul demand of both upper and lower parts of shell; for the shell boiler with inside diameter of shell as 800~1000mm, at least one inspection hole shall be arranged on shell or head (tube plate); the quantity of hand-holes arranged at the lower part of vertical shell boiler shall meet the requirements of cleaning and inspection and shall not be less than 3.
5.1.8 For the boiler with furnace, the combustion shall be completed in furnace. Water entering into the boiler shall not directly scour the boiler furnace. For the boiler with inside diameter of furnace greater than 1400mm or heat input greater than 12MW, at least 3 measuring points shall be arranged in boiler for temperature measurement.
5.1.9 The hydraulic test pressure shall meet the requirements of GB/T 16508.1.
5.1.10 Corrosion allowance
The corrosion allowance shall meet the following requirements:
a) For the pressure parts with nominal thickness δ>20mm and all plain components, the corrosion allowance may be 0mm;
b) For the pressure parts with nominal thickness δ≤20 mm, the minimum corrosion allowance may be taken as 0.5mm;
c) In the case of possible severe corrosion, the value of corrosion allowance may be correspondingly increased.
5.2 Performance requirements
5.2.1 Design performance
5.2.1.1 The manufacturer shall ensure that the boiler reaches the rated evaporation or rated thermal power under design conditions, and shall provide the load range for economical operation of boiler.
5.2.1.2 The steam quality of boiler, where operating under design conditions, shall reach the following indexes:
For water-fire tube boiler and shell boiler, the steam humidity of saturated steam boiler shall not be greater than 4%; the steam humidity of superheated steam boiler at the superheater inlet shall not be greater than 1%; the salt content of superheated steam shall not be greater than 0.5mg/kg.
The temperature deviation tss of superheated steam of industrial steam boiler shall meet the following requirements:
a) Where tss≤300℃, its deviation range is ( )℃;
b) Where 300℃
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Symbols and Units
5 Basic Requirements for Design
6 Cylindrical Parts Subject to Internal Pressure
7 Cylindrical Boiler Furnace, Circular Flue, Smoke Tube and Other Part Subject to External Pressure
8 Convex Head, Boiler Furnace Top, Hemispherical Boiler Furnace and Convex Tube Plate
9 Flat Plates and Tube Plates with Tension Brace (Support and Reinforcement)
10 Tension Braces and Reinforcing Parts
11 Flat Cover and Cover Plate
12 Foot Ring
13 Opening and Opening Reinforcement
14 Welded Tee Junction
15 Verification Method for Determining Maximum Permissible Operating Pressure of Part
Appendix A (Informative) Design Calculation of Pressure Part on Cast-iron Boiler
Appendix B (Informative) Design Calculation of Rectangular Header
Appendix C (Informative) Design Calculation of Water Tube Plate
锅壳锅炉
第3部分：设计与强度计算
1 范围
GB/T 16508的本部分规定了锅壳锅炉基本受压元件的设计和结构要求，并给出了铸铁锅炉(附录A)、矩形集箱(附录B)和水管管顿(附录C)的基本设计要求。
本部分适用于承受内压圆筒形元件、承受外压圆筒形元件、封头、管板、拉撑件、下脚圈，以及开孔和补强的设计计算。
2规范性引用丈件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注'日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。
GB/T 1576工业锅炉水质
GB/T 2900.48 电工名词术语锅炉
GB/T 9252气瓶疲劳试验方法
GB/T 12145火力发电机组及蒸汽动力设备水汽质量
GB 13271 锅炉大气污染物排放标准
GB/T 16508.1—2013 锅壳锅炉 第1部分：总财
GB/T 16508.2锅壳锅炉 第2部分：材料
GB/T 16508.4锅壳锅炉 第4部分：制造、检验和验收
NB/T 47013(JB/T 4730)承压设备无损检测
TSG G0001锅炉安全技术监察规程
TSG G0002锅炉节能技术监察管理规程
3术语和定义
GB/T 16508.1和GB/T 2900.48界定的术语和定义适用于本文件。
4符号和单位
本部分中各章节通用的符号含义和单位如下：
Et——计算温度时材料的弹性模量，MPa；
p——计算压力，MPa；
[p]——校核计算最高允许工作压力，MPa；
pr——锅炉额定压力，MPa；
p0——工作压力，MPa；
ts——对应于计算压力下的介质饱和温度(热水锅炉为额定出水温度)，℃；
tc——计算温度，℃；
tmave——介质额定平均温度，℃；
Δpa——设计附加压力(安全阀整定压力)，MPa；
Δph——受压元件所受液柱静压力，MPa；
Δpf——介质流动阻力附加压力，MPa；
η——修正系数；
[σ]J——许用应力，MPa。
5设计基本要求
5.1 结构要求
5.1.1 锅炉设计应遵守TSG G0001《锅炉安全技术监察规程》、TSG G0002《锅炉节能技术监督管理规程》等安全技术规范，并应采用先进的技术，使产品满足安全、可靠、高效、经济和环保的要求。
5.1.2按本部分的规定确定所需考虑的计算载荷及所需进行的载荷计算。按本部分中的有关强度计算公式或应力分析计算公式和规定，确定受压元件的最小需要厚度。
当采用试验或者其他计算方法确定锅炉受压元件强度时，应当将有关的技术资料和方案以及所做试验的条件和数据提交国家质检总局特种设备安全技术委员会，由该技术委员会评审后，报国家质检总局核准，才能进行试制、试用。
5.1.3筒体、炉胆壁厚和长度
5.1.3.1 当锅壳内径大于1 000 mm时，锅壳的取用壁厚应不小于6 mm；当锅壳内径不超过1 000 mm时，锅壳筒体的取用壁厚应不小于4 mm。
5.1.3.2炉胆内径不应超过1 800 mm，其取用壁厚应不小于8 mm，并且不大于22 mm；当炉胆内径小于或等于400 mm时，其取用壁厚应不小于6 mm；卧式内燃锅炉的回燃室，其筒体的取用壁厚应不小于10 mm，并且不大于35 mm。
5.1.3.3胀接连接的筒体、管板，取用壁厚应当不小于12 mm。外径大于89 mm的管子不应采用胀接结构设计。
5.1.3.4卧式锅壳锅炉平直炉胆的计算长度应不超过2 000 mm，如果炉胆两端与管板扳边对接连接时，平直炉胆的计算长度可以放大至3 000 mm。
5.1.4蒸汽锅炉的最低安全水位应高于最高火界100 mm，但锅壳内径不大于1 500 mm的卧式锅壳锅炉的最低安全水位应高于最高火界75 mm。锅炉的最低及最高安全水位应当在图样上标明。
5.1.5受压部件(元件)结构的型式、开孔和焊缝的布置应尽量避免或减少复合应力和应力集中。使用的焊缝类型应符合设计文件和GB/T 16508.4。要进行无损检测的焊缝应设计成能够进行所要求的无损检测的型式。
5.1.6锅炉主要受压元件的主焊缝(锅壳、炉胆、回燃室、集箱等的纵向和环向焊缝，以及封头、管板、炉胆顶和下脚圈的拼接焊缝等)应当采用全焊透的对接接头；锅炉受压元件的焊缝不得采用搭接结构；拉撑件不应当采用拼接。
5.1.7锅壳内径大于1 000 mm时，应在筒体或者封头(管板)上开设人孔；由于结构限制导致人员无法进入锅炉时，可以只开设检查孔；对锅壳内布置有烟管的锅炉，人孔和检查孔的布置应当兼顾锅壳上部和下部的检修需求；锅壳内径为800 mm～1 000 mm的锅壳锅炉，至少应当在筒体或者封头(管板)上开设一个检查孔；立式锅壳锅炉下部开设的手孔数量应当满足清理和检验的需要，其数量应当不少于3个。
5.1.8对于有炉胆的锅炉，燃烧应在炉胆内完成。进入锅炉的水不得直接冲刷炉胆。炉胆内径大于1 400 mm或热量输入大于12 MW的锅炉，至少在炉内设3个测点进行温度测量。
5.1.9水压试验压力应符合GB/T 16508.1的规定。
5.1.10腐蚀裕量
腐蚀裕量应符合如下规定：
a)名义厚度δ>20 mm的受压元件以及所有平直部件，腐蚀裕量可为0 mm；
b)名义厚度δ≤20 mm的受压元件，可取0.5 mm作为最小腐蚀裕量；
c)在可能发生严重腐蚀的情况下，应相应地增加腐蚀裕量的值。
5.2 性能要求
5.2.1 设计性能
5.2.1.1 制造厂应保证锅炉在设计条件下达到额定蒸发量或额定热功率，并提供锅炉经济运行负荷范围。
5.2.1.2在设计条件下运行，锅炉的蒸汽品质应达到以下指标：
饱和蒸汽锅炉的蒸汽湿度对水火管锅炉和锅壳锅炉不应大于4％；过热蒸汽锅炉过热器入口的蒸汽湿度不应大于1％；过热蒸汽含盐量不应大于0.5 mg/kg。
工业用蒸汽锅炉的过热蒸汽温度tss的偏差应符合如下规定：
a)当tss≤300℃时，其偏差范围为( )℃；
b)当300℃
GB/T 16508.3-2013 引用如下标准： |
GB/T 16508.3-2013被如下标准引用：
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