Standard No.:	GB/T 50051-2021
English Name:	Technical standard for chimney engincering
Chinese Name:	烟囱工程技术标准
Professional Classification:	GB    National Standard
Issued by:	MOHURD
Issued on:	2021-04-09
Implemented on:	2021-10-1
Status:	valid
Superseding:	GB 50051-2013 Code for design of chimneys GB 50078-2008 Code for Construction and Acceptance of Chimney Engineering
Language:	English
File Format:	PDF
Word Count:	130000 words
Price(USD):	4000.0
Delivery:	via email in 1 business day

Technical standard for chimney engineering 1 General rules 1.0.1 This standard is formulated according to relevant laws and regulations in order to standardize and guide the design, construction and acceptance of chimneys, ensure personal health, life and property safety and ecological environment safety, and meet the basic needs of chimney engineering construction. 1.0.2 This standard is applicable to the design, construction and acceptance of newly-built concrete chimneys, FRP chimneys, steel chimneys, brick chimneys and other single tube chimneys, single liner chimneys and multi-liner chimneys, as well as the reinforcement and anti-corrosion reconstruction of existing chimneys. 1.0.3 In addition to the requirements of this standard, the design, construction and acceptance of chimneys shall also meet the requirements of relevant current national standards. 2 Terms 2.0.1 chimney high-rise structure for discharging flue gas 2.0.2 dry chimney chimney for discharging flue gas with relative humidity less than 60% and temperature not below 90℃ 2.0.3 humid chimney chimney for discharging flue gas with relative humidity greater than 60% and temperature above 60℃ but below 90℃ 2.0.4 wet chimney chimney for discharging flue gas with saturated relative humidity and temperature not above 60℃ 2.0.5 self-supporting chimney chimney with its shaft forming a stable structure, without any additional support 2.0.6 guyed chimney chimney with the shaft and the cable forming a stable system 2.0.7 framed steel chimney steel chimney with its own vertical load mainly borne by the liner, horizontal load mainly borne by the steel frame 2.0.8 single tube chimney ordinary chimney with lining and insulation directly supported on the bracket of the shell or with lining directly stuck on the shell 2.0.9 single liner chimney chimney with a liner set in the shell 2.0.10 multi-liner chimney chimney with two or more liners sharing an outer shell or a frame 2.0.11 liner exhaust tube in the shell of single liner chimney and multi-liner chimney 2.0.12 lining self-bearing structure supported on the shell bracket in sections or the casting body directly attached to the shell via anchor bars distributed on the shell, which is used for protecting the insulation or the shell 2.0.13 shaft parts above the chimney foundation, including the shell, insulation, lining, etc. 2.0.14 shell outermost structure of chimney shaft, which is the load-bearing part of the whole shaft 2.0.15 insulation structure placed between the shell and the lining, to ensure that the heating temperature of the shell does not exceed the specified maximum temperature 2.0.16 self-supporting liner exhaust tube mainly bearing compressive stress in vertical direction and supported by outer barrel in horizontal direction under the action of deadweight load 2.0.17 suspended liner exhaust tube mainly bearing tensile stress in vertical direction and supported by outer barrel in horizontal direction under the action of gravity load 2.0.18 confining bed acid-resistant mortar layer outside the brick liner, used to seal the flue gas and prevent or reduce the leakage of flue gas 2.0.19 flue part of the flue gas exhaust system, used to guide flue gas into the chimney 2.0.20 vortex shedding cross-wind resonance phenomenon occurs when the vortex shedding frequency generated by airflow passing through the chimney surface is equal to or close to the natural vibration frequency of the structure 2.0.21 critical wind speed for vortex shedding minimum wind speed when the chimney is exposed to cross-wind resonance 2.0.22 lock in wind speed range in which vortex shedding is generated when the vortex shedding frequency of the wind is equal to or close to the natural vibration frequency of the structure 2.0.23 strake (vane) vibration damping device for reducing vortex shedding response by suppressing the regular vortex shedding of wind 2.0.24 fiber reinforced plastic (FRP) liner liner with fiber and its products as reinforcement and synthetic resin as matrix, which is manufactured, connected and installed in sections by mechanical winding molding process 2.0.25 reactive flame-retardant resin resin that contains flame-retardant elements such as chlorine, bromine and phosphorus in its main chain, and can make the cured FRP materials have the properties of difficult ignition and self-extinguishing after leaving the fire without adding or adding a small amount of auxiliary flame-retardant materials such as antimony trioxide. This kind of resin is not flame retardant in liquid state 2.0.26 matrix resin part in FRP material 2.0.27 limited oxygen index (LOI) minimum oxygen concentration (volume percent fraction) required to maintain balanced combustion of the test piece in the mixed gas of nitrogen and oxygen under specified conditions 2.0.28 flame-spread rating index value measured by standard method for FRP laminate with thickness of 3mm ~ 4mm, resin content of 70% ~ 75% and reinforced by glass fiber chopped strand mats 2.0.29 winding angle included angle between the length direction of the fiber bundle or belt wound on the mandrel and the meridian or bus of the mandrel 2.0.30 reinforcement fiber material added into resin matrix, which can significantly improve the mechanical properties of composite products 2.0.31 heat-deflection temperature (HDT) temperature at which the resin casting specimen produces the specified deformation amount under the specified static load according to the tube supported beam model in the specified liquid heat transfer medium heating at a constant rate 2.0.32 glass transition temperature temperature (Tg) corresponding to the glass transition (i.e. when the resin casting specimen reaches a certain temperature at a certain temperature rising rate, it changes from a hard glassy brittle state to a flexible elastic state, and its physical parameters change discontinuously), which is the basis for determining the maximum working temperature of the resin, and its value is usually 15℃ ~ 25℃ higher than the heat-deflection temperature 2.0.33 hydraulic sliding form process of continuous construction with the embedded supporting rod of the shell (wall) as the supporting point, using the hydraulic jack to lift the working platform and sliding form 2.0.34 motor-driven ( hydraulic) promote form process of intermittent construction of inverted mould with the preformed hole or embedded supporting rod of the shell (wall) as the supporting point, using the motor or hydraulic jack to lift the working platform and sliding form 2.0.35 two-side sliding form process of carrying out hydraulic sliding form construction for the shell and the lining simultaneously 2.0.36 hydraulic jacking method for installing steel chimney or steel liner in segments from top to bottom by using hydraulic jacking equipment 2.0.37 hydraulic lifting method for installing steel chimney or steel liner in segments from top to bottom by using hydraulic lifting equipment 2.0.38 pneumatic jacking method for installing steel chimney or steel liner in segments from top to bottom by using pneumatic jacking equipment 2.0.39 assessed working life for existing chimney working life of existing chimneys estimated based on reliability assessment under specified conditions 2.0.40 design working life for strengthening of existing chimney working life of the strengthened chimney specified in the strengthening design, which can be used for intended purpose without re-inspection and identification 2.0.41 design working life for corrosion resistance of chimney working life of the chimney specified in the anti-corrosion design, which can be used for intended purpose under normal construction and maintenance conditions 3 Basic requirements 3.1 Design requirements 3.1.1 In this standard, the limit state design method based on probability theory is adopted, the reliability of structural members is measured by reliability index, and design expression of partial coefficient is adopted for structural calculation. 3.1.2 The limit state design of chimney structure and its accessory members shall include: 1 Limit state of bearing capacity: the chimney structure or accessory members reach the maximum bearing capacity, such as strength failure, local or overall instability, and excessive deformation making it unsuitable for continuous bearing, etc. 2 Serviceability limit state: chimney structure or accessory members reach the specified limit for normal working, such as the limits of deformation, crack and maximum heating temperature, etc. 3.1.3 The bearing capacity limit state shall be designed based on different design conditions, including basic combination, accidental combination and seismic combination of action effects. The serviceability limit state shall be designed according to the standard combination, frequent combination and quasi-permanent combination of action effects. 3.1.4 The safety grade and structural importance coefficient of chimneys shall meet the following requirements: 1 The safety grade of a chimney shall not be less than Grade II. When the chimney height is not less than 200m or the unit capacity is not less than 300MW, the safety grade of the chimney shall be Grade I. 2 The structural importance coefficient γ0 of a chimney shall not be less than those specified in Table 3.1.4. Table 3.1.4 Structural importance coefficient γ0

Foreword i 1 General rules 2 Terms 3 Basic requirements 3.1 Design requirements 3.2 Construction requirements 3.3 Acceptance requirements 4 Materials 4.1 Masonry 4.2 Concrete 4.3 Steel bar and steel product 4.4 Material thermal calculation index 5 Loads and actions 5.1 General requirements 5.2 Wind load 5.3 Platform live load and dust load 5.4 Ice load 5.5 Seismic action 5.6 Temperature action 5.7 Flue gas pressure calculation 6 Foundation 6.1 General requirements 6.2 Calculation of bearing capacity of foundation 6.3 Calculation of foundation deformation 6.4 Foundation stability calculation 6.5 Calculation of slab foundation 6.6 Pile foundation calculation 6.7 Structure regulations 6.8 Earthwork and foundation pit construction 6.9 Reinforcement engineering construction 6.10 Formwork construction 6.11 Concrete engineering construction 6.12 Construction quality inspection 7 Concrete chimney 7.1 General requirements 7.2 Additional bending moment calculation 7.3 Calculation of shell bearing capacity at ultimate limit state 7.4 Calculation of shell at serviceability limit state 7.5 Structure regulations 7.6 Reinforcement engineering construction 7.7 Formwork construction 7.8 Concrete engineering construction 7.9 Construction quality inspection 8 Steel liner and brick liner 8.1 General requirements 8.2 Calculation regulations 8.3 Self-supporting steel liner 8.4 Suspended steel liner 8.5 Brick liner 8.6 Design structure 8.7 Manufacture 8.8 Welding 8.9 Installation 8.10 Construction quality inspection 9 FRP liner 9.1 General requirements 9.2 Materials 9.3 Laminate design 9.4 Self-supporting FRP liner 9.5 Suspended FRP liner 9.6 Connection and stiffening 9.7 Design and detailing 9.8 Manufacture 9.9 Installation 9.10 Construction quality inspection 10 Steel chimney 10.1 General requirements 10.2 Framed steel chimney design 10.3 Self-supporting steel chimney 10.4 Guyed steel chimney 10.5 Installation 11 Brick chimney 11.1 General requirements 11.2 Calculation of horizontal section 11.3 Calculation of hoops 11.4 Calculation of circumferential bar 11.5 Calculation of vertical bar 11.6 Design structure 11.7 Construction 11.8 Construction quality inspection 12 Anticorrosion of chimney 12.1 General requirements 12.2 Selection of chimney materials as well as structures and types 12.3 Anticorrosion of brick chimney 12.4 Anticorrosion of single tube reinforced concrete chimney 12.5 Anticorrosion of brick liner for single liner chimney and multi-liner chimney 12.6 Anticorrosion of steel liner for single liner chimney and multi-liner chimney 12.7 Anticorrosion of steel chimney 12.8 Construction quality inspection 13 Chimney platform 13.1 General requirements 13.2 Platform design 13.3 Platform fabrication and installation 13.4 Construction quality inspection 14 Lining and insulation construction 14.1 General requirement 14.2 Brick lining (liner) and insulation 14.3 Lining of amorphous material 14.4 Construction quality inspection 15 Flue 15.1 General requirement 15.2 Underground flue 15.3 Overhead flue 15.4 Construction quality inspection 16 Aeronautical obstacle lamp and signs 16.1 General requirement 16.2 Distribution of obstacle lamps 16.3 Design requirements of aeronautical obstacle lamp 16.4 Construction quality inspection 17 Reinforcement and anti-corrosion renovation of existing chimneys 17.1 General requirement 17.2 Design principles of chimney reinforcement and anti-corrosion renovation 17.3 Selection of reinforcement and repair materials 17.4 Top hoisting of fiber reinforced plastic (FRP) liner 17.5 Construction quality inspection 18 Construction quality inspection of ancillary works 19 Winter construction 19.1 General requirement 19.2 Foundation 19.3 Brick chimney shell 19.4 Concrete chimney shell 19.5 Steel chimney (steel liner) and steel members 19.6 Single tube chimney lining 20 Construction safety 21 Chimney drying 22 Acceptance of engineering quality Annex A Vertical average additional stress coefficient of circular foundation Annex B Stability coefficient of welded cylinder section under axial compression Annex C Records on quality management and inspection of construction site Annex D Quality acceptance records of inspection lot Annex E Quality acceptance records of subitem works Annex F Quality acceptance record of subsection (sub-subsection) works Annex G Pre-acceptance records of unit (sub-unit) work quality Annex H Completion acceptance record of unit (sub-unit) work quality Explanation of wording in this standard List of quoted standards