Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
This standard was proposed by the China Electricity Council.
This standard is under the jurisdiction of the Technical Committee on Power Station Steam Turbine of Standardization Administration of Power Industry.
This standard is formulated for the first time.
Any comments or suggestions during the implementation of this standard may be fed back to the Standardization Center of the China Electricity Council (No.1, 2nd Lane, Baiguang Road, Beijing, 100761, China).
Aluminium tube bundles used in indirect air cooling system of thermal power plant
1 Scope
This standard specifies the requirements for design, manufacture, inspection and acceptance of aluminium tube bundles used in indirect air cooling system.
The aluminium tube bundles used in indirect air cooling system in this standard is applicable to indirect air cooling system of thermal power plant with cooling water as medium, with the maximum operating pressure not greater than 0.6MPa and the maximum working temperature not greater than 100℃, and equipped with mixing condenser or surface condenser.
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 referenced document (including any amendments) applies.
GB 150 (all parts) Pressure vessel
GB/T 1804 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications
GB/T 3190 Wrought aluminium and aluminium alloy - Chemical composition
GB/T 3191 Aluminium and aluminium alloys extruded bars, rods
GB/T 3880 (all parts) Wrought aluminium and aluminium alloy plates, sheets and strips for general engineering
GB/T 4437.1 Aluminium and aluminium alloy extruded tubes - Part 1: Seamless tubes
GB/T 6892 Wrought aluminium and aluminium alloys extruded profiles for general engineering
GB/T 6893 Aluminium and aluminium alloys cold drawn (rolled) seamless tubes
GB/T 13912 Metallic coatings - Hot dip galvanized coatings on fabricated iron and steel articles - Specifications and test methods
JB/T 4711 Coating and packing for pressure vessels transport
NB/T 47007 Air-cooled heat exchangers
NB/T 47013 (all parts) Nondestructive testing of pressure equipments
NB/T 47015 Welding specification for pressure vessels
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
cooling tube
aluminum tube in which the flowing medium exchanges heat from inside to outside
3.2
fin
expanded surface which improve heat-transfer capability by increasing heat transfer area and enhancing flow disturbance and is generally connected with cooling tube by expansion or other means
3.3
cooling element
combined unit with several cooling tubes of the same specification connected with reinforcing plates and tube plates
3.4
top header
header arranged on the top when the cooling element is installed vertically
3.5
bottom header
header arranged on the bottom when the cooling element is installed vertically
3.6
fixed tray
part clamping the header and tube plate with U-shape bolt
3.7
operating pressure
rated pressure that the aluminum tube bundle may bear under normal working conditions
3.8
design pressure
maximum pressure set on the top of the tube bundle, which, together with the corresponding design temperature, is taken as the basic design load condition of the tube bundle and whose value is not less than the operating pressure
3.9
design temperature
mental temperature of element set with the tube bundle under normal working conditions, which should be the maximum working temperature of the medium cooled plus 10℃
3.10
finned ratio
ratio of the total surface area of fin in contact with the air to that of the cooling bare tube
4 General requirements
The design, manufacture, inspection and acceptance of aluminium tube bundles used in indirect air cooling system shall meet the technical requirements of the drawing and the relevant requirements of NB/T 47007.
5 Materials
5.1 Designation of materials used for main parts and components
Materials for main parts and components shall be selected according to Table 1. The materials shall meet the requirements of GB/T 3190.
Table 1 Materials for main parts and components
S.N. Name Material designation Standard
1 Fin 1050A H18/H19 GB/T 3880
2 Header 6063 T6 GB/T 6892
3 Irregular interface tube 6063 T6 GB/T 4437.1
4 Interface flange 5052 H112 GB/T 3880
5 Fixed tray 5754 H112 GB/T 3191
6 Cooling tube 1050A GB/T 6893
7 Tube plate and connecting plate 5A05 and 6063 T6 GB/T 6892
5.2 Seal ring material requirements
O-ring shall be made of chloroprene rubber or ethylene propylene diene monomer rubber, its Shore hardness shall meet the hardness requirements under the service environment, and it shall be oil resistant and oxidation resistant, with a hardness of 65±5 Shore A, and a service temperature of -40℃ ~+125℃.
6 Design
6.1 Requirements for arrangement of tube bundle cooling element
The top header and the bottom header shall be designed as a single integrated component. See Annex A for the outline and assembly arrangement of cooling tube bundle unit.
6.2 Design pressure of tube bundle
The design of pressure-bearing components of the tube bundle shall meet those specified in GB 150.2. The design pressure of the tube bundle shall be 0.6MPa, the pressure in air pressure test shall be 1.1 times of the design pressure, and that in water pressure test shall be 1.25 times of the design pressure.
6.3 Design of tube bundle structure
6.3.1 If the cooling element adopts double tube passes, the opening area of the baffle plate of the counter-current header shall not be less than 50% of the total flow area of all tubes of the cooling element.
6.3.2 The diameter of the inlet and outlet flanges of the header shall be selected according to the control value meeting the corresponding flow rate and the resulting resistance. Buffer baffle plate shall be set at the inlet flange, and the materials shall be erosion resistant.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Materials
6 Design
7 Manufacture
8 Inspection and acceptance
9 Marking, packaging, storage and transport
Annex A (Informative) Outline and assembly arrangement of cooling tube bundle unit
