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
鍋殼鍋爐
第3部分：設計與強度計算
1 范圍
GB/T 16508的本部分規定了鍋殼鍋爐基本受壓元件的設計和結構要求，并給出了鑄鐵鍋爐(附錄A)、矩形集箱(附錄B)和水管管頓(附錄C)的基本設計要求。
本部分適用于承受內壓圓筒形元件、承受外壓圓筒形元件、封頭、管板、拉撐件、下腳圈，以及開孔和補強的設計計算。
2規范性引用丈件
下列文件對于本文件的應用是必不可少的。凡是注日期的引用文件，僅注'日期的版本適用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改單)適用于本文件。
GB/T 1576工業鍋爐水質
GB/T 2900.48 電工名詞術語鍋爐
GB/T 9252氣瓶疲勞試驗方法
GB/T 12145火力發電機組及蒸汽動力設備水汽質量
GB 13271 鍋爐大氣污染物排放標準
GB/T 16508.1—2013 鍋殼鍋爐 第1部分：總財
GB/T 16508.2鍋殼鍋爐 第2部分：材料
GB/T 16508.4鍋殼鍋爐 第4部分：制造、檢驗和驗收
NB/T 47013(JB/T 4730)承壓設備無損檢測
TSG G0001鍋爐安全技術監察規程
TSG G0002鍋爐節能技術監察管理規程
3術語和定義
GB/T 16508.1和GB/T 2900.48界定的術語和定義適用于本文件。
4符號和單位
本部分中各章節通用的符號含義和單位如下：
Et——計算溫度時材料的彈性模量，MPa；
p——計算壓力，MPa；
[p]——校核計算最高允許工作壓力，MPa；
pr——鍋爐額定壓力，MPa；
p0——工作壓力，MPa；
ts——對應于計算壓力下的介質飽和溫度(熱水鍋爐為額定出水溫度)，℃；
tc——計算溫度，℃；
tmave——介質額定平均溫度，℃；
Δpa——設計附加壓力(安全閥整定壓力)，MPa；
Δph——受壓元件所受液柱靜壓力，MPa；
Δpf——介質流動阻力附加壓力，MPa；
η——修正系數；
[σ]J——許用應力，MPa。
5設計基本要求
5.1 結構要求
5.1.1 鍋爐設計應遵守TSG G0001《鍋爐安全技術監察規程》、TSG G0002《鍋爐節能技術監督管理規程》等安全技術規范，并應采用先進的技術，使產品滿足安全、可靠、高效、經濟和環保的要求。
5.1.2按本部分的規定確定所需考慮的計算載荷及所需進行的載荷計算。按本部分中的有關強度計算公式或應力分析計算公式和規定，確定受壓元件的最小需要厚度。
當采用試驗或者其他計算方法確定鍋爐受壓元件強度時，應當將有關的技術資料和方案以及所做試驗的條件和數據提交國家質檢總局特種設備安全技術委員會，由該技術委員會評審后，報國家質檢總局核準，才能進行試制、試用。
5.1.3筒體、爐膽壁厚和長度
5.1.3.1 當鍋殼內徑大于1 000 mm時，鍋殼的取用壁厚應不小于6 mm；當鍋殼內徑不超過1 000 mm時，鍋殼筒體的取用壁厚應不小于4 mm。
5.1.3.2爐膽內徑不應超過1 800 mm，其取用壁厚應不小于8 mm，并且不大于22 mm；當爐膽內徑小于或等于400 mm時，其取用壁厚應不小于6 mm；臥式內燃鍋爐的回燃室，其筒體的取用壁厚應不小于10 mm，并且不大于35 mm。
5.1.3.3脹接連接的筒體、管板，取用壁厚應當不小于12 mm。外徑大于89 mm的管子不應采用脹接結構設計。
5.1.3.4臥式鍋殼鍋爐平直爐膽的計算長度應不超過2 000 mm，如果爐膽兩端與管板扳邊對接連接時，平直爐膽的計算長度可以放大至3 000 mm。
5.1.4蒸汽鍋爐的最低安全水位應高于最高火界100 mm，但鍋殼內徑不大于1 500 mm的臥式鍋殼鍋爐的最低安全水位應高于最高火界75 mm。鍋爐的最低及最高安全水位應當在圖樣上標明。
5.1.5受壓部件(元件)結構的型式、開孔和焊縫的布置應盡量避免或減少復合應力和應力集中。使用的焊縫類型應符合設計文件和GB/T 16508.4。要進行無損檢測的焊縫應設計成能夠進行所要求的無損檢測的型式。
5.1.6鍋爐主要受壓元件的主焊縫(鍋殼、爐膽、回燃室、集箱等的縱向和環向焊縫，以及封頭、管板、爐膽頂和下腳圈的拼接焊縫等)應當采用全焊透的對接接頭；鍋爐受壓元件的焊縫不得采用搭接結構；拉撐件不應當采用拼接。
5.1.7鍋殼內徑大于1 000 mm時，應在筒體或者封頭(管板)上開設人孔；由于結構限制導致人員無法進入鍋爐時，可以只開設檢查孔；對鍋殼內布置有煙管的鍋爐，人孔和檢查孔的布置應當兼顧鍋殼上部和下部的檢修需求；鍋殼內徑為800 mm～1 000 mm的鍋殼鍋爐，至少應當在筒體或者封頭(管板)上開設一個檢查孔；立式鍋殼鍋爐下部開設的手孔數量應當滿足清理和檢驗的需要，其數量應當不少于3個。
5.1.8對于有爐膽的鍋爐，燃燒應在爐膽內完成。進入鍋爐的水不得直接沖刷爐膽。爐膽內徑大于1 400 mm或熱量輸入大于12 MW的鍋爐，至少在爐內設3個測點進行溫度測量。
5.1.9水壓試驗壓力應符合GB/T 16508.1的規定。
5.1.10腐蝕裕量
腐蝕裕量應符合如下規定：
a)名義厚度δ>20 mm的受壓元件以及所有平直部件，腐蝕裕量可為0 mm；
b)名義厚度δ≤20 mm的受壓元件，可取0.5 mm作為最小腐蝕裕量；
c)在可能發生嚴重腐蝕的情況下，應相應地增加腐蝕裕量的值。
5.2 性能要求
5.2.1 設計性能
5.2.1.1 制造廠應保證鍋爐在設計條件下達到額定蒸發量或額定熱功率，并提供鍋爐經濟運行負荷范圍。
5.2.1.2在設計條件下運行，鍋爐的蒸汽品質應達到以下指標：
飽和蒸汽鍋爐的蒸汽濕度對水火管鍋爐和鍋殼鍋爐不應大于4％；過熱蒸汽鍋爐過熱器入口的蒸汽濕度不應大于1％；過熱蒸汽含鹽量不應大于0.5 mg/kg。
工業用蒸汽鍋爐的過熱蒸汽溫度tss的偏差應符合如下規定：
a)當tss≤300℃時，其偏差范圍為( )℃；
b)當300℃
GB/T 16508.3-2013 引用如下標準： |
GB/T 16508.3-2013被如下標準引用：
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