In the field of major equipment in China, the current power generation equipment has the smallest gap with the international level, and is also the first to achieve a breakthrough. This evaluation is not easy, but it is appropriate. From the introduction of technology, digestion and absorption, to independent innovation, optimization and improvement, and then to leaps and bounds, and shoulders abroad, China's power generation equipment manufacturing industry has been proud of over 30 years, leaped through the struggle of leading power generation equipment companies, and witnessed major technical equipment. 30 years in the field. From the initial processing of raw materials, to map manufacturing, to joint design, joint bidding, and cooperative production, it is on an equal footing with large foreign companies and large companies, and today is in an advantageous position in the competition. Harbin Electric Group, Shanghai Electric Group, Dongfang Electric Group Leading companies such as the company take the heavy load and take the unique technology path of “introduction, digestion, absorption and self-innovation†to fully drive the core competitiveness of China's power generation equipment manufacturing industry to a qualitative leap. Thermal power equipment clean and efficient Under the guidance of national policies, China's thermal power sector has opened a new era of clean and efficient power generation units and has become a landmark milestone for China's motor industry's independent innovation. From the late 1980s, China began to pay attention to the development of supercritical thermal power units and imported large-capacity supercritical units from abroad. In 1992, the first two sets of 600,000 kilowatts of supercritical thermal power units were installed at the Shidongkou Second Plant in Shanghai. This time the introduction of a combination of technology and trade, focusing on the introduction of the boiler and steam turbine supercritical technology and design calculation software, and through the participation in the design and other methods, trained a group of professional and technical personnel, for the localization of supercritical units work Ample preparation. In order to further promote the localization of supercritical units, China will add the development of 600,000 kilowatts of supercritical units to the National Key Technical Equipment Development Project of the “Ninth Five-Year Plan†in 2000, and determine the first phase of Huaneng Qinbei Power Plant 2×600,000 kilowatts. The critical unit is the first domestic 600,000 kilowatt supercritical unit demonstration project. With the two domestically produced 600,000 kilowatts of supercritical coal-fired units being put into operation one after another, their main equipments and important auxiliary engines have basically got rid of the dependence on foreign technology, and the localization rate of equipment has greatly increased. On the basis of the successful manufacture of the supercritical units, Harbin, Shanghai, and the East's three major power generation equipment manufacturing groups imported one million kilowatts of ultra-supercritical technology from companies such as Mitsubishi, Toshiba, Siemens, and Alstom, respectively, and are guaranteed by foreign companies. The performance of the cooperative approach, the final trial of successful million-kilowatt ultra-supercritical units. At present, China has successfully mass-produced 600,000 and 1 million kilowatts of supercritical and even ultra-supercritical thermal power units. After testing, performance indicators such as power generation efficiency, power supply standards, and coal consumption of China-made supercritical and ultra-supercritical units have been achieved. International advanced level. So far, China has become the world's most-injected multi-kilogram supercritical unit. At the same time, China has also continued to promote the use of large-scale air-cooled units, and in 2010 successfully put into operation the world's first (sets) million kilowatt-class ultra-supercritical direct air-cooled units. At present, China has become the country with the largest number of air-cooled units in the world. Experts once praised him and said, “In the development of thermal power 600,000 kilowatts of supercritical units and 1 million kilowatts of ultra-supercritical units, China has made things in the world in the past few decades.†World-class hydropower equipment In the past 30 years, China’s hydropower project construction and equipment technology have made unprecedented progress and remarkable achievements. In particular, thanks to the Three Gorges Project, China has achieved a leap from 300,000 kilowatts to 600,000 kilowatts, and hydropower equipment manufacturing has advanced into the world. Horizontal ranks. The Three Gorges Power Station installed a total of 32 (sets) 700,000 kilowatt hydropower generating units with a total capacity of 22.4 million kilowatts. It is the largest hydropower unit in the world in terms of stand-alone capacity. It is extremely difficult to design and manufacture, and it is extremely difficult for global hydro-generator sets manufacturers. Very challenging. In the initial stage of the construction of the Three Gorges Project in 1993, in order to meet the design requirements and promote the rapid development of the equipment manufacturing industry, in the international tendering of 26 sets of 700,000 kilowatts of units on the left and right banks of the Three Gorges Power Station, the state provided 14 sets of left bank projects for external tendering. The principle of “joint design and cooperative manufacturing†requires the successful bidder of foreign advanced manufacturing companies to cooperate with Chinese manufacturing companies, and transfer of technology and subcontract manufacturing; the second phase of the right bank project is based on the introduction, digestion, and absorption of left bank technology. Made in China. At the same time, the state has also invested heavily in Dongfang Motor and Haji Motors for technological transformation and the transformation and expansion of large and heavy-duty CNC equipment and plants to meet the technical requirements of the high-strength and high-performance of large units of the Three Gorges Power Station. In the bidding for the right bank and underground power station of the Three Gorges Power Station in 2003, the design capabilities of Haji Motors and Dongfang Electric Machine Co., Ltd. all met the requirements of the project, and on this basis, they successfully digested, absorbed, reinvented, and reformed the technology of foreign companies. The monopoly of foreign hydropower equipment manufacturing technology has achieved a technological leap. The 12 units (sets) of units on the right bank of the Three Gorges Power Station were all put into operation in 2008. After evaluation, 8 units (sets) of domestically produced units have reached the same level as foreign units, and their hydraulic stability and unit efficiency are also better than that of the left bank units, reaching international advanced level. Level. The successful development of the Three Gorges Project's 700,000 kilowatts of large-scale hydropower units indicates that China's hydropower equipment manufacturing industry has entered the world's advanced level. The successful implementation of the Three Gorges Project's introduction technology and independent innovation also proves that major projects are the main battlefield for China's motor industry to achieve technological progress. . In the construction of the Three Gorges Underground Power Station, Xiangjiaba, Xiluodu and other follow-up projects, domestic hydropower units have always been in a dominant position in the competition, regardless of their technical level or share of successful bidders. Significant progress in nuclear power equipment Nuclear power construction in China began in the 1980s. In December 1991, the first phase of the Qinshan Nuclear Power Plant was successfully connected to the grid to generate electricity, ending the history of nuclear-free electricity in China's mainland. In 2003, the Party Central Committee and the State Council made the decision to promote the construction of nuclear power. In October 2007, the State Council promulgated the "Mid-term and Long-term Development Plan for Nuclear Power (2005-2020)", and nuclear power construction entered a new stage of development. The construction of the Daya Bay nuclear power plant in 1987 opened the prelude to the commercialization of large-scale nuclear power plants with millions of kilowatts in China. Under the condition of keeping its basic structure unchanged, combined with operational experience, China has made several major technological improvements and re-innovations on the models introduced from France, and explored the formation of second-generation improved million-kilowatt pressure water with its own brand. Nuclear reactor technology, the second generation of improved nuclear power technology. At present, the second-generation improved nuclear power equipment has reached 90% of its capacity, and this type of nuclear power unit has become the main model of the nuclear power unit under construction in China. China has also basically achieved the independent design, autonomous manufacturing, independent construction, and independent operation of nuclear power plants. While continuing to properly construct the second generation of improved nuclear power units, and with the ultimate goal of improving the safety and economy of nuclear power, in 2003, the National Leading Group for the Independence of Nuclear Power was established, and the international bidding for three generations of independent nuclear power projects was initiated. . On July 24, 2007, the National Nuclear Power Technology Corporation, Sanmen Nuclear Power Corporation, Shandong Nuclear Power Corporation and the Westinghouse Consortium and its subcontractors respectively signed the contract for relying on the project nuclear island procurement and the corresponding technology transfer contract. Among them, China will cooperate with the United States in the design and construction of three demonstration projects in Zhejiang Sanmen and Shandong Haiyang, a total of four AP1000 nuclear power units, and purchase some equipment from the United States. The United States transferred AP1000 design technology, equipment manufacturing technology, construction technology and machine composition technology. To this end, the National Nuclear Power Technology Corporation has formulated a "three-step" strategy. Starting from the 5th (set) AP1000 unit, China will independently undertake the design and manufacture of nuclear power equipment, and it will be improved and improved to form China with independent property rights. Third-generation nuclear power technology. At present, China's third-generation nuclear power has formed a complete equipment manufacturing system. At the same time, on the basis of fast reactors and high temperature and temperature reactor technologies, China has developed fourth-generation nuclear power technology research and development and quietly rang the doors of the fourth-generation nuclear power industry. Plate rolling is a process of continuous three-point bending of sheet metal using a plate rolling machine. The equipment puts the sheet material between the upper and lower work rolls when rolling. The upper roller is raised and lowered vertically, and the two lower rollers rotate and move horizontally relative to the axis of the upper roller. When the upper roll descends, the plate is plastically deformed and bent between the upper and lower work rolls. The continuous rotation of the bottom roller drives the steel plate to advance and retreat through the friction between the plate and the roller to complete the coiling. Rolling Machine,Three-Roller Bending Machine,Four-Roller Bending Machine,Roll Forming Machine Rugao Yaou Import & Export Trade Co., Ltd , https://www.ntyaou.com
1. Pre-bending. When the plate is rolled, there is a length at both ends of the plate that does not bend because it does not touch the upper roller. It is called the remaining straight edge. In the process, the minimum force arm at which the plate starts to bend is called the theoretical remaining straight edge. The bending form (symmetrical bending, asymmetrical bending) is related.
2. Centering. The purpose of centering is to make the generatrix of the workpiece parallel to the roller axis to prevent skew.
3. Roll round. Rolling is the main process of product forming, which is divided into two types: one-time feed and multiple feeds. Multiple feeds are commonly used for rolling thick plates. The number of feeds depends on the technological constraints (such as the maximum allowable deformation during cold rolling) and equipment constraints (such as non-slip conditions and power conditions). When the rebound of the cold coil is significant, a certain amount of overcoiling must be added.
4. Straightening round. The purpose of rounding is to make the curvature of the entire circle as uniform as possible to ensure product quality. The general rounding process is divided into three steps:
(1) Load: According to experience or calculation, adjust the work roll to the position of the required maximum correction curvature.
(2) Rounding: Roll the roller 1 to 2 turns under the corrected curvature to make the entire curling rate uniform.
(3) Unloading: gradually unload the load, so that the workpiece is rolled several times under the gradually reduced correction load.