This standard specifies the design criteria, calculation methods, and protection effect detection of sacrificial anode cathodic protection for seawater cooling water systems in coastal power plants. This standard applies to sacrificial anode cathodic protection for seawater cooling water systems in coastal power plants. It should also be used as a reference for sacrificial anode cathodic protection of cooling water systems in other coastal factories and enterprises, estuary power plants, and inland power plants in areas with high salinity groundwater. GB/T 16166-1996 Sacrificial anode cathodic protection for seawater cooling water systems in coastal power plants GB/T16166-1996 Standard download decompression password: www.bzxz.net

ICS 27.140
National Standard of the People's Republic of China
GB/T 16166—1996
Sacrificial anode cathodic protection for seawater cooling system in coastal power station
Published on January 25, 1996
National Technical Supervision Bureau
Implemented on October 1, 1996
National Standard of the People's Republic of China
Sacrificial anode cathodic protection for seawater cooling system in coastal power station
Sacrificial anode cathodic protection for seawater cooling system in coastal power station1Subject content and scope of application
GB/T 16166-1996
This standard specifies the design criteria, calculation method and protection effect detection of sacrificial anode cathodic protection in seawater cooling water systems of coastal power plants. This standard is applicable to sacrificial anode cathodic protection in seawater cooling water systems of coastal power plants. For other coastal factories and enterprises, estuary power plants and power plants in areas with high salinity groundwater, cathodic protection of water systems with galvanic anodes should also be considered. 2 Reference standards GB 4948 Aluminum-zinc-aluminum alloy galvanic anodes GB4950 Zinc-aluminum alloy sacrificial anodes SY 119 Technical standard for application of alloy sacrificial anodes 3 Design criteria 3.1 For equipment, components and channels composed of steel, iron, copper alloys, stainless steel, etc., the protection potential range should reach -0.85 ~ -1.DV (relative to lower copper/saturated copper sulfate reference voltage, the same below). 3.2 For equipment composed of iron, steel, cast iron, copper alloys, etc., the surface protection potential shall not be less than -0.80 V. 4 Design of galvanic anode cathodic protection 4.1 Selection of galvanic anode materials 4.1.1 The anode should be selected in accordance with GB 4948, GB 49 = G, SY JI9 relevant provisions of the materials, or electrochemical performance is better than the above standards, and through the adjustment of the material
4.1.2 resistivity less than 100 n·crm water and fresh water medium, should be used for the alloy anode, 4.1.3 resistivity of 100 ~ 200 cml fresh water medium, should be used for zinc alloy anode or suitable alloy anode,
4.1.4 resistivity greater than 200ncm cooling water, should be used for magnesium alloy anode or suitable aluminum alloy sacrificial electrode. 4.1.5 The protection of the cooler used in the power supply should be zinc alloy sacrificial anode. 4.2 Determination of sacrificial anode specifications
The specifications of the anode should be determined according to the structure of the equipment, components, pipes, maintenance interval time, and the number of years required for protection. The recommended aluminum alloy and zinc alloy anode size is shown in Table 1.
State Administration of Technical Supervision 1 9 96-01-25 approved for implementation on October 1, 1996Www.bzxZ.net
W Equipment name Ball
Water head and water diversion steel kidney
Submersible
Full rotation net
Third filter
Condenser
CB/T16166—1996
Table 1 Selection and layout principles of each equipment Anode size, mm
(200+280)×150×800
(200.+280)×150×1200
(115—13$)×130×1001)
80X100 x 000
(115-1185)X130. 0×120×50
110X120×50
$220100
400×=×35
(115 +133)×130×1 000
(115--135)×130X5
80100X1000
80100500
Li set up Huang Kangze
tree branch support frame
low humidity will be the guide rail two balance each, get the remaining cloth on the fence
guide soft book board back and
half the average low elastic position below the guide rail, and the cabinet
installation is complex, the current screen is very high. Note
answer each shielding area to install anode
water treasure and distribution Xia food gold pipe energy steam||tt ||The bottom of the device, the electrode on the quality plate is installed at a distance of more than 500mm from the ordinary plate. For example, the anode on the original plate is installed at a distance of less than 400mm from the pipe. It should be installed on a simple and quick place that does not affect the net drawing and closure. When repairing, the electrode can also be installed on the end pipe of the tightly connected equipment. The water supply chamber is evenly distributed in the pipe, and it is recommended to install an electrode at the manhole. ) The dielectric research shows that the service life of the electrode is within the range of 25~%0m. 4.3 Calculation of current generated by anode The current generated by anode shall be calculated according to formula (1); I - AE/R Anode service life 25--3n 10--12 0.1-1.0 The current generated by a single anode is A; Where: f is the electrode driving potential, V: zinc alloy anode AF = 0.25 V. Jinhui gold anode takes E = 0.30 V, magnesium alloy anode takes AE-AF-0.65 V; R is the anode water resistance. W. CB/T 16166-1996 The anode water resistance is calculated according to formula (2) and formula (3) according to the anode installation method. Flat anode:
Stand anode:
Where: R—anode water resistance,
seawater resistivity, Q·cmi
.-electrode length, cm;
Where: C
anode thickness, cm;
anode thickness, m!
Anode cross-sectional equivalent radius, calculated according to formula (4): rC/2R
anode cross-sectional circumference, cm.
4.4 Calculation of anode service life
The recommended anode service life is shown in Table 1.
The service life of the anode should be an integer of the equipment maintenance interval, calculated according to formula (5): GQ
8760X1
Wherein:
Anode service life,
Weight of each anode, kg;
Actual capacitance of the anode, A+h/kg, Q=780A.h/kg for zinc alloy anode, Q2400A·h/kg for aluminum alloy anode; Q=】100A·b/kg for magnesium alloy anode; Anode utilization coefficient, value 0.85;
Average current generated by each anode, A: Calculated according to formula (6): Im -- (0, 6 -- 0. 8))
Current generated by each anode, A.
4.5 Calculation of protected area
4.5.1 Calculate the immersion area of ​​the protected equipment, components and belts of different materials and different surface conditions according to the geometric dimensions. 4. 5.2
The inner surface area of ​​the tube bundle of tube bundle cooling equipment such as steam boiler is calculated according to formula (7), S-12 D4
Where: s.
The inner surface area of ​​the tube bundle, m*,
: The number of tube bundles in a single water pipe,
The inner diameter of the condenser tube, cut.
4.6 Selection of protection current density
The protection current density is selected according to Table 2.
W Yue Name
Fence repair cabinet cleaning machine
Energy conversion network
Secondary filter
Steamer
Ball collection network
Colding group
GB/T 16166—1996
Table 2 Protection current density of different equipment, components and pipelines
Boiler, spider bran
40~~ 50
4.7 Calculation of protection current
80~100
Alloy
150~200
120~-150
The protection current of the protected equipment, components and pipelines shall be calculated according to (8): I = is.
Wherein: 1-
Protection current mA.
Stainless steel
Degree, mA/m2
150~-200
100-150
Protection current density of the protected equipment, components and pipelines under various materials and different surface conditions, mA/mS,--Protective area m* of the protected equipment, components and pipelines under various materials and different surface conditions. Calculation of the number of cathodic anodes The number of anodes required for protected equipment, components and pipelines is calculated according to formula (9), N-IE4: N-IE and number of electrodes Protection current A: Each anode generates a current of A. 4.9 Anode arrangement 4.9.1 The anodes are arranged evenly and symmetrically, and the anode installation position should take into account the current shielding effect. 4.9.2 The anode arrangement for related equipment, components and pipelines is shown in Table 1. 5 Design of cathodic protection of the outer wall of buried pipeline network Cathodic protection design of cathodic protection of the outer wall of buried pipeline network shall be carried out in accordance with Appendix A (reference document). 6 Acceptance, storage and installation of anodes
6.1 Acceptance
Anode quality should be accepted in accordance with relevant standards and order contract requirements. 6.2 Storage
Anodes should be stored in a warehouse, moisture-proof and waterproof, and should not be exposed to acid, alkali, salt, or oil or paint. (9)
WGB/T 16166--1996
6.3 Installation
Install anodes according to the anode layout diagram. Welding should be firm and ensure good electrical connection. See Figure 1, Figure 2, and Figure 3 for the fixing method. Figure 1 Schematic diagram of bracket anode installation
1 Anode: 2—iron core+3—bracket: 4—calcium certificate 15-sample whole Figure 2 Schematic diagram of flat anode installation
1—anode: 2—iron core: 3—ene: 1—solder plate WGB/T16166-1996
Figure' Schematic diagram of screw-fixed flat anode installation 1—anode: 2—reinforced needle 3—filler: 4—iron 5—steel plate 7 Protection effect detection and sacrificial anode replacement
7.1 Protection potential measurement
7.1.1 Dispersed structures such as trash racks, rotary filters, and trash cleaners can use portable copper/saturated copper sulfate reference electrodes to regularly measure the protection potential of underwater structures. The potential must comply with the provisions of Article 3.1. 7.1.2 Pipelines, condensers and other equipment use standard zinc-gold reference electrodes or silver/silver chloride reference electrodes. The protection potential should comply with the provisions of 3.1 and 3.2. 7.1.3 The protection potential ranges of the three reference electrodes of steel and titanium are shown in Table 3. Table 3 Protection potential range relative to three reference electrodes Ratio electrode
Judgment of protection potential
Protection potential
7.2 Protection degree measurement
Copper/paste and copper sulfate reference electrode
0. 85 ~ 1. 0#
Zinc alloy reference electrode
0.05-0.25
Silver/phosphorized silver electrode/ditch water
C. 80-- 1, 00
Install two sets of test pieces made of the same material as the protected object, with the same size and surface condition, one set is electrically connected to the protected object, and the other is electrically insulated. The corrosion weight loss of the two groups of test pieces shall be measured regularly, with a weighing accuracy of 0.01. When: the protection degree is calculated according to formula (10), the protection degree should be greater than %,
Wu Zhong: Department
-protection degree, %;
.Q
Corrosion loss of insulating test piece;
GB/T 16166—1996
Q—Corrosion weight loss of electrical connection test piece·B7.3 Shutdown to check the protection effect
Inspect the corrosion degree of equipment, components, and pipelines, thoroughly remove the corrosion products on the cathode surface, and observe the dissolution and residual of the anode. 7.4 Replacement of sacrificial anodes
7.4.1 When the remaining amount of anode is less than the amount required for the next maintenance interval, the anode must be replaced. 7.4.2 During the use of the anode, if the surface does not dissolve and the potential of the protected structure does not reach the minimum protection potential, it should be replaced in time. W.A1 Scope
GB/T 16166-1996
Appendix A
Buried general network sacrificial anode protection for coastal power plants (forbidden items)
The buried metal structure of power plants is complex, and the scope of protection includes buried pipelines, ground grids, installed power systems, pile foundations and metal storage tank bottoms, among which the main purpose is to protect buried pipelines.
A2 Avoidance of sacrificial anode materials
42.1 When the soil resistivity is 10·m, or when the structure is affected by water below the average high tide level, zinc alloy sacrificial anodes are used. A2.2 When the soil resistivity p>10a·m, continuous alloy sacrificial anodes are used. A3 Filling materials for underground anodes The filling material formula of alloy and magnesium alloy anodes is shown in Table A1. Table A1 Filling material formula of alloy and magnesium alloy anodes Filling materials of alloy and magnesium alloy anodes The assembly of underground anodes is shown in Table A1, Figure A1 Schematic diagram of buried anode assembly 1-contact plate 2-anode electrode 3-seal head 11 fast core 5-anode 6-filling material 7-cloth bag Na2O-10H&) WA5 Selection of underground anodes GB/t 16166-1996
Select anode specifications and models according to soil filling electrification rate and short service life. Common anode specifications can be found in Table A2. Specifications and models of buried anodes for use with A2.
Peak anode
ZAC-D1
ZAC-D2
MAZ-D!
MAZ-D2
A5 Calculation of current generated by alcoholic anode
1 000× (58. 5+78, 5)× 68
800×(55+74)X65
700×(130+150)×125
700×(100+120)×105
The generated current of each anode is calculated according to the formula (A1): WAE/R
Where: Ir-
The generated current of each anode, mA:
AE-—Anode driving potential mV For zinc anode, take AE=25 0mV model anode takes E-650 power V: R anode grounding resistance.0t calculated according to formula (A2), 2Z
wherein,,
anode length.m
filling bag length, m,
D——anode equivalent diameter, m1
filling bag diameter m
-soil electrical conductivity, -mr
Pt filler resistivity, nm:
burial depth from the ground to the center of the anode.m.
A7 Calculation of the service life of smoky anode
The service life of the anode is calculated according to formula (A3): 4
The service life of the anode is used!
-actual capacitance of anode. A·h/kg1
G——weight of each anode, kgh
1/K--. Anode utilization coefficient. Take 0.85
+enhui
acid amount of filler
..-(A2)
（A3)
WGB/T 16166—1996
I.--.-average current generated by each anode, mA; calculated according to formula (A4): I. . 0. 7I.
Where: I——current generated by each anode, tiA. A8 Calculation of the number of sacrificial anodes
A8. 1 The protection current density of newly built steel pipelines with enhanced coating protection is 2~3 mA/m. 48.2 The calculation method of pipeline protection area, protection current and number of anodes is the same as that of 4.5.1.4.7.4.8. A42
A8.3 The grounding grid of steel vertebral foundation and far away from steel pipe should be equipped with anodes of the same type as the protection pipeline. One anode should be added to each steel pile and one anode should be added to each 150m grounding flat steel.
A9 Arrangement and installation of sacrificial anodes
A9.1 The electrodes are generally evenly arranged in pairs. They can also be relatively concentrated in the parts with low soil resistivity. A9.2 The anode installation method is shown in Figure A2.
Figure A2 Anode arrangement and installation diagram
1-Pipeline; 2-Moon cable:3—Intelligent structure + 4—Anode plate; 5—Connection pieceAnode installation precautions:
When the anode is moved and buried, the anode cable is not allowed to be pulled to avoid the breakage of the screen seal joint: the anode welding piece should be welded firmly and the welding place should be supplemented with a waterproof layer: the anode filling material should be soaked with water;
The clay should be backfilled around the anode filling package, and bricks, sand and gravel should not be mixed with debris. Additional instructions:
GB/T 16166—1996
This standard was proposed by China Shipbuilding Industry Corporation and issued by the 725th Institute of the 7th Research Institute of China Shipbuilding Industry Corporation. This standard was drafted by the 7.5th Institute of the 7th Research Institute of China Shipbuilding Industry Corporation, Shandong Huangdao Power Plant, East China Electric Power Design Institute, and Northwest Electric Power Design Institute.
The main drafters of this standard are Chen Renxing, Wei Yunlong, Ju Guinian, Wu Jianhua, Liu, Tu Mingbi, and Zhu Bangjia. 11
W
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