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 Wysłany: Pią 14:46, 22 Kwi 2011 Temat postu: Christian Louboutin Greece ijd zga wwok lau |
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Surface Technology in Electrical and Application Prospect of metal structure
Abstract: Three Gorges Project is the Quality of the projects,[link widoczny dla zalogowanych], life, reliability, and repair and maintenance costs, depending on the level of multi-disciplinary technology development. On the surface engineering technology in the Three Gorges Project and electrical equipment and metal structure work on the application of a comprehensive discussion and analysis of the Three Gorges Project and mechanical equipment, metal structure surface preparation, surface coating technology and products the technical requirements. Keywords: metal structure, mechanical and electrical equipment Surface 1 Introduction surface engineering, is the result of surface preparation, through the surface coating, surface modification techniques or more complex surface treatment, changing the solid metal surface or non-metallic surface morphology, chemical composition and stress state in order to obtain the required surface properties of systems engineering. Three Gorges Project is often referred to as full-length 72% (1679m), in effect, like a Three Gorges Project as a comprehensive utilization of water resources engineering, electrical equipment and metal structure of its total weight of 50 million t, accounting for the total project cost estimate of 1 / 3. Surface engineering with multiple interdisciplinary, integrated and complex features for the application of a variety of surface technology and composite technology for surface features, is the dominant one of the key technologies of industrial development. Three Gorges Project is the Mechanical and electrical equipment in the international tender technical conditions, clearly the application of surface processing technology, surface technology and the requirements of complex surface technology to improve the surface properties of materials, parts and components increased, effectively improve equipment reliability, long life and ease of maintenance and repair. Surface engineering technology in the Three Gorges Project construction has been widely used. 2 application of surface technology, the Three Gorges Project Three Gorges Project by the object retaining and discharge structures, power generation, building and navigation buildings, the dam axis length 2309.47m. Discharge structure located in the middle of the river bed, with surface hole, deep hole and diversion bottom; power plant discharge structure located in the left and right sides, as the dam toe power house, a total of 26 sets of 700MW hydro-generating unit installed . Arranged in the hub of the left bank of navigation structures, including two-consecutive five permanent lock, in-line vertical ship lift and the construction of the navigation of the temporary lock. 2.1 generator set and other electrical and mechanical equipment Three Gorges Power Station and auxiliary mechanical and electrical equipment hydro-generating unit total weight of about 26 million t. Buried in the concrete pieces of equipment, year round, the erosion of sediment flow turbine flow passage components and perennial exposure to the air surface of the mechanical and electrical equipment are the basis of need application of surface engineering theory, high-quality, high efficiency, low consumption of surface technology, In parts of the surface equipment and rigorous treatment to ensure that equipment reliable operation. 2.2 hydraulic gates and metal structure buried the Three Gorges project hydraulic gate parts, gate body, water pipes and other metal structures hoist total about 26 million t. Dam and power station which combined total of 30 different specifications of the gate 539, with all kinds of permanent ship lock miter gate, drain valves, filling a total of 89, both of about 73 000 t. Working environment which is the worst flood diversion and the deep bottom of the radial gate, the maximum working head up to 85m, flow rate of 35m / s, and a partial opening of the requirements. 2.3 Three of external work area Traffic Engineering Traffic Engineering of the metal structure of external surface protection, surface coating, including bridges, loading and unloading heavy pieces of lifting equipment on the docks and the metal structure of the surface treatment and steel pipe pile and coal container terminal the surface of the gray steel tank corrosion. Three Gorges Project, including external transport medium and large metal structure bridge 34, which links both sides of the Xiling Yangtze River Bridge dam 1118.66m. 3 application of surface technology, the Three Gorges Project and Practice 3.1 Three test electrical equipment and metal structure work environment Three surface mechanical and electrical equipment and metal structural surface, according to its functional requirements, were exposed to the atmosphere in the indoor and outdoor and humid atmosphere, alternating wet and dry environment. Hydraulic conditions in the static and dynamic hydraulic conditions,[link widoczny dla zalogowanych], high-speed water flow and sediment environment combined with the concrete work of running. (1) exposed to the atmosphere of work are: a large crest sector cranes and tracks, automatic grasping beams, open the top of high voltage electrical plant equipment, high pressure outlet tower, the main factory gate, power station tailrace gantry crane and rail and some local gate exposed parts. There are permanent lock, lock and vertical ship lift the temporary bridge machine, beams and raking machines. Those exposed to the atmosphere the surface of the structure and equipment, annual withstand sun and rain, snow frost attack. (2) working in the indoor air of equipment are: turbine generator set, the exposed surface of the transformer, the main factory building of various bridges pay machine, beam, rail, high-voltage equipment, plant, equipment and other high-current bus unit auxiliary equipment such as pumps, air compressor, refrigerator surface powerhouse roof, miter gate hoist and its ancillary equipment, medium and low voltage switchboards, power plate,[link widoczny dla zalogowanych], protected enclosure surface. (3) working in the humid atmosphere structure and equipment, such as: power plant intakes vertical hydraulic hoist, long-term storage in the door in the library access door, and embedded parts, gate boom, tail water drain valve, drainage pump turbine cover and so on. These devices in humid air, year round, easy to rust and corrosion. (4) working in the wet and dry cycle in the structure prone to surface damage such as: miter gate, all gates of the gate slot embedded parts, locks floating bollards, gates and outlet surface hole access door, etc. . Alternating wet and dry, some frequent, some alternate frequency little impact on the structure of the surface is different. (5) working under hydrostatic conditions is equipped with: miter gate, gate and Stoplog maintenance, power inlet access door, deep hole and surface hole overflow section of the access door and so on. They are all around the platen before the gates open or whereabouts. (6) the work of hydrodynamic conditions inlet gate of the power station, pressure pipe, trash rack access door accident, including the turbine volute flow components, water guide, runner, base rings and tail pipes in the elbow and so on. (7) in the harsh environment in particular flushing hole in the work of the emergency service gate and door, working the door bottom, deep work of the door, lock lost emptying culvert valves, lined care and runner are in the high velocity of sediment in the work and operation of water, sediment abrasion of the damaging effects of its material and surface treatment have special requirements. ( Some combination of steel and concrete surfaces, such as pressure pipe wall, open and close all gates and buried bodies and pieces of steel, turbine steel lined, spiral case, stay ring and generators embedded parts, equipment based embedded parts and so on. 3.2 Three Gorges Dam environmental characteristics of air and water, the Three Gorges Dam in Yichang, Hubei Province City, two bucket Township, this area is the south temperate and subtropical zone, its climate is characterized by high temperature, high humidity, fog and windy small, small temperature difference between autumn and more. Average relative humidity of air dam 75.8%, the average temperature of 21 ~ 22C, the maximum temperature of 43.9C, the lowest 9.8C. Average annual rainfall of 1251mm, to 7-8 months higher. S02 concentration in the atmosphere higher, more serious acid rain, the rainfall pH value of 5.44, a large atmospheric corrosion. Average flow of the Three Gorges dam site up to 450 billion years, m3, annual average flow 14400m3 / s, the water contains sediment, annual average sediment concentration 1.2kg/m3. Maximum sediment concentration measured 10.5kg/m3. Bed sediment is relatively small, the majority of suspended sediment, the average size of less than 0.1mm. Water with biological effects, such as sub-sea clam, etc.. 7.95 PH value of the river, dissolved O2 is 6.4mg / L. The work of moving equipment and underwater structure to withstand the hydrodynamic speed of more than different, trash rack over the gate velocity of approximately lm / s, pressure pipe of about 8m / s, lock culvert of about 20m / s, deep holes, bottom outlet gate at 30 ~ 35m / s, bottom sediment within 18 ~ 28m / s, turbine runner blades of about 30 ~ 40m / s. These structures and equipment, especially in the high-speed flow of sand to work with the structure and equipment, cavitation and sand abrasion facing the joint damage. 3.3 Three Gorges Project equipment and steel structures technology experiment surface Surface Science and Engineering to make the combination of the Three Gorges Project to the air environment, water environment and working environment characterized by experimental studies of effective engineering measures proposed , to improve the surface properties of materials, effectively extending the service life and save resources, improve productivity and reduce environmental pollution. To this end, China Three Gorges Project Development Corporation commissioned the Institute of Materials Protection, Wuhan has a variety of different coating materials and surface technology combined treatment experiments. (1) atmospheric exposure experiment started from January 1995, in the Three Gorges dam in Yichang City and Zigui city of more than 30 domestic and foreign manufacturers than 120 anti-corrosion system for coupon test specimen,[link widoczny dla zalogowanych], which 42 kinds of organic coating systems, thermal spray metal system 7. Now tests are still ongoing. (2) Water exposure experiment were exposed to the water the whole environment (immersion), and alternating wet and dry environment for the conduct of the trial. Downstream of the Three Gorges dam experimental arrangement at the Gezhouba 40km conducted immersion specimens immersed in Gezhouba Lock II who first word on the gate door, alternating wet and dry specimen under the installation of lock gates in the first Gezhouba II's miter door. Test coating materials, organic coating system 35, thermal spray metal system 7, 1 species of electrochemical protection. (3) indoor accelerated corrosion test were 13 manufacturers of 34 anti-corrosion system, that is water-soluble inorganic zinc-rich class of 4, 3 alcohol-soluble inorganic zinc-rich class, 4 epoxy zinc-rich class, 13 zinc-rich primer / intermediate coat / finish, 5 kinds of metal spray coating, 8 kinds of metal spray coating / sealer to test samples and were designated using the conventional cross destructive samples in neutral salt spray accelerated conditions corrosion test, in 5% salt solution immersion test, ultraviolet aging climate accelerated corrosion testing,[link widoczny dla zalogowanych], water and salt water in the electrochemical comparison test, the coating protection performance testing of electrical science and coating and the substrate (or other coating) interface stick Results load test. Coupon field test these preliminary results, has mechanical and electrical equipment and metal structures in the tender documents has been applied to the technical specifications, contract suppliers will be based on the requirements of surface coating and surface modification. 3.4 application of surface technology, the Three Gorges Project Three Gorges Project since practice in December 1994 has been officially started, the surface in bridges and culverts, docks, construction equipment, the substation, storage and transportation are relatively widely used. (1) external transport projects in Three Gorges bridge Bridge 4 Bridge, the bridge 7 of bridge 23, total 34, total length of 3793m where there are more distinctive Liantuo Bridge, Cork River Bridge, under the prison north and south across the Yangtze River Bridge and on both sides of Xiling Yangtze River Bridge. Liantuo bridge length 340.87m, the main bridge is in the continuous concrete deck steel arch bridge with three holes. The total width of the arch bridge 20m. Direct impact on the life of steel bridge safety. Steel arch surface protection, with three finishes, respectively, primer, intermediate coat and topcoat, the total dry film thickness of 305μm. In the rust before painting the surface treatment of Sa2.5 level, roughness Ra30. River Bridge, under the prison length 286.06m, for the tin structure of the three dolphins, the largest steel arch span of 160m for the structure. Steel arch thermal spray aluminum surface protection. Huangbo River bridge length 284.76m, desktop double column of seven pile pier structures, the largest steel arch span of 160m for the structure. Steel surface by hot zinc spray arch. Coating the steel arch of the life requirements of 20 years. Xiling Yangtze River Bridge across the Yangtze River Dam is a major north-south channel, and the other bridge, are both permanent road bridge. Bridge length of 1118.66m, the main span of 900m hole for the single-span steel box with two hinge stiffening beam suspension structure. Two main tower 120m, for the reinforced concrete three-door cabinet structure. The main tower base 12 in the Φ2.2m drilled pile. The two main cables in parallel from the 10,010 high-strength galvanized steel wire φ5.1mm composition, diameter φ570mm, each main cable length 1478m, weighing about 2300t. Two sides each have a gravity anchor. Bridge construction process in order to solve the cable over the saddle to adjust the balance of forces, military equipment maintenance Surface Engineering Research Center, presented a composite anti-friction coating design and the corresponding site construction plan to replace foreign adoption in the saddle Vice-friction needle roller installed in thousands of pieces of the program, so that the smooth passage of the saddle in place. Using this technology allows friction reduction compound friction coefficient reduced by 1 times, significant savings in construction costs. In addition, the surface of the main tower and the cables have adopted the protective surface coating, the surface of the main tower of the total film thickness of 280μm. Coating life of 5 years without eradication of just repairing the original paint coating again. (2) use of closed road special highway management, traffic safety to ensure the day and night, with highways and rails glare network, network and barrier wave beam surface protection by hot dip galvanizing, zinc coating thickness of 61 ~ 85μm. (3) terminal in the Three Gorges Dam has a Yangjiawan port containers, general cargo terminal and a loading and unloading heavy pieces of heavy equipment terminals. Terminal Three Gorges Dam water port cargo throughput to ensure the safe operation of the very important. Yangjiawan underwater φ800/1000 the steel pier is pier foundation piles, steel pipe piles 3, killed by the CPI 16mm steel, aluminum surface with a chlorinated rubber and chlorinated rubber anticorrosive paint for processing. 2 × 300/50t lifting heavy pieces of terminal equipment for the 2 sets of 300t crane car, bridge structure, weight 300t. Beam bridge crane and lifting all the metal structure, the outer surface of the non-contact surface of mechanical parts, have carried out a surface coating treatment. By shot peening the surface of the first mechanical hand or hand-rust treatment, then coated with primer, intermediate coat and topcoat, epoxy iron red, respectively, shop primer, epoxy micaceous iron rust and can be coated polyurethane finish. (4) Ash body is steel storage jars, all storage tanks total weight of about 1830t, its tank, transit warehouse for coating processing, iron red as primers, synthetic resin mixed paint used as intermediate coat and topcoat, underground pipes conveying fly ash coal tar pitch with epoxy paint. Surface engineering practice in the application of the Three Gorges Project, not only played on the surface of metal and non-metallic protective effect, but also add to the beauty of the building. It is not comprehensive examination, coated materials and process re-application is successful, the service life to be further follow-up investigation and trials.
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