What is a dual water internally cooled generator, and the development background of a dual water int

Stator and rotor.

Both are water-cooled generators, known as dual water internal coolant generators. The core of the dual water internal coolant generator is air-cooled, and under the action of fans at both ends of the rotor, the air passes through.

Stator windings. The end enters the air gap, which is then collected by the ventilation groove of the stator core.

zone, after the cooling of the air cooler, enters the negative pressure area of the fan from the air ducts on both sides to form the circulation of the air path.

Air-cooled or hydrogen-cooled generator is to use air or hydrogen to cool the coil and core from the surface, because the cooling effect is poor, in order to control the temperature of the coil and the core within the allowable range, the cross-section of the wire and the core of the coil is larger, the copper loss and iron loss of the generator are smaller, and the heat generated is less. As a result, air-cooled or hydrogen-cooled generators are bulky.

The double water internal cooling generator is cooled directly from the inside of the coil wire with water, and the cooling effect is very good, even if the cross-section of the coil wire and the iron core is small, the temperature of the coil and the iron core can be controlled within the allowable range in the case of large copper loss and iron loss of the generator.

The material used to make a dual-water internal cooled generator can be reduced by about 30% compared to an air-cooled or hydrogen-cooled generator of the same capacity. Due to the weight reduction and volume reduction of the double water internal cooling generator, it not only reduces the cost and is convenient for lifting, transportation and installation, but also saves the cost of the generator foundation and the plant. However, the efficiency of the dual-water internal cooled generator is low due to the large copper loss and iron loss.

The efficiency of large air-cooled generators is about 97 98; The efficiency of a hydrogen-cooled generator is about 98 99; The generator efficiency of water cooling is about 96 98.

If the efficiency of the generator is reduced by 0 5o l 0o, the coal consumption of power generation will increase by 0 5o 1 0. For large generator sets, the fuel cost increased by using water cooling for one year is also very considerable. Therefore, some large generators do not use water internal cooling, but use hydrogen cooling with better cooling effect and higher generator efficiency.

Units 5 and 9 of Hongyanchi Power Plant are all dual-water internal cooled generators.

It is named because the stator winding and rotor winding of the generator are cooled with water by hollow copper wire. Because the specific heat of water is large and the heat can be taken away directly, the efficiency of the generator can be improved. Compared to other cooling motors, it is possible to manufacture more powerful motors with the same materials.

Is this a practical application after it was developed?

In 1958, when the Second Five-Year Plan began, the contradiction of insufficient electricity was prominent. To this end, the state requires the Shanghai Electric Machinery Factory to manufacture more steam turbine generators to support industrial and agricultural production. However, the manufacture of steam turbine generators required a rotating shaft and a retaining ring, two important components that had not yet been produced in China at that time and had to be imported from abroad.

People give a few shafts and a few sets of protective rings, and only a few turbine generators can be produced. In this case, to meet the needs of the state for power station equipment, only in the cooling medium and cooling method can be found. Because the cooling medium and the way it is cooled directly affects the power generation capacity of the generator.

Air cooling is the least efficient, with hydrogen cooling being 3 4 times higher than air cooling, and water cooling being 40 50 times higher than air cooling. In terms of cooling methods, there are also internal cooling and external cooling, and the effect of internal cooling is better than external cooling. However, in terms of manufacturing technology, water cooling is more difficult than hydrogen cooling, and internal cooling is more difficult than external cooling, especially the rotor winding water internal cooling, and there is no precedent in the world.

Shanghai Electric Machinery Factory has only been manufacturing steam turbine generators for 4 years, and the largest single unit capacity is only 10,000 kilowatts, but in order to meet the needs of the country, they have broken the old way of developing steam turbine generator production in various countries around the world, and are determined to adopt water internal cooling, and try to set the generator and rotor double water internal cooling steam turbine generator. At the beginning of the year, Meng Qingyuan, the chief engineer of the plant, organized some professors and lecturers of Jiaotong University and Zhejiang University, as well as Wang Zuomin and Jin Chuanqi of the factory. Some foreign materials seen by the comrades attending the meeting have not reached a conclusion on the issue of double water internal cooling.

Especially when the rotor rotates at a high speed of 3000 revolutions per minute, can the water flow pass smoothly due to the effect of centrifugal force? Even if the water flow can pass through the rotor rotating at high speed, will the dynamic balance of the rotor be disrupted by the air bubbles generated in the waterway? These are all issues that foreign experts are worried about.

Therefore, some comrades in the discussion held that China's industrial foundation is weak, and if we take the lead in the trial production of dual-water internally cooled steam turbine generators, we will inevitably encounter many difficulties. Finally, it was decided to try to produce a steam turbine generator with stator water internal cooling and rotor hydrogen internal cooling.

The manufacture of this kind of generator has foreign successful experience to learn from, and it is easy to succeed. As a result, Shanghai Electric Machinery Factory started with stator water cooling, and began to design trial production in May 1958, and was scheduled to be trial-produced in 1962. Later, after the anti-waste and anti-conservative "double anti" movement, the goal of making it was set in 1960.

In order to quickly apply the research results, Zheng Guanghua rushed to Shanghai from Hangzhou the next day, hoping that the Shanghai Electric Machinery Factory could try to produce a double-water internal cooled hidden pole steam turbine generator. The next day, Meng Qingyuan presided over a meeting of senior technical personnel to listen to Zheng Guanghua's introduction of the structural scheme and test results of the water cooling of the rotor winding conductor.

At the beginning of July, the Shanghai Municipal Committee of the Communist Party of China issued an instruction to the Shanghai Electric Machinery Factory, in order to ensure that the total capacity of steam turbine generators next year will reach 3.5 million kilowatts, and the Shanghai Electric Machinery Factory should actively carry out the trial production of double water internal cooling steam turbine generators. In accordance with this instruction, Shanghai Electric Machinery Factory set up a design and test team for double-water internally cooled steam turbine generators on July 7 with Wang Geng as the team leader and Chen Tongji, Zhang Qinglie and others participating. Two teachers from Zhejiang University participated in the initial work, followed by six new graduates and 10 fresh graduates from Xi'an Jiaotong University.

On July 14, 1958, Liu Xiyao, deputy director of the State Science and Technology Commission, summoned Meng Qingyuan, Wang Geng and teachers from Zhejiang University of Shanghai Electric Machinery Factory. It is hoped that the Shanghai Electric Machinery Factory will design and prototype the water-cooled rotor of the 12,000 kW steam turbine generator within one or two months. That night, Meng Qingyuan returned to the factory to convene relevant leading cadres, technicians and workers, and comprehensively started the "three combinations" battle of design and trial production.

On October 27, 1958, the world's first 10,000 kW 3,000 rpm double-water internally cooled steam turbine generator was born in Shanghai Electric Machinery Factory.

In December of the same year, the USSR held a conference on the cooling of large turbine generators at the Leningrad "Electricity" plant. In addition to the major motor manufacturing plants and research units of the Soviet Union, the meeting was also attended by Wu Tianlin, deputy chief engineer of the Harbin Electric Machinery Plant in Poland, Hungary, and China, and Wang Geng of the Shanghai Electric Machinery Factory. According to the instructions of the leaders, Wu Tianlin announced at the conference that China had built a 12,000 kilowatt 3,000 rpm double water internally cooled steam turbine generator, which caused the shock of the delegates.

Aleksev, president of the USSR Electrical Engineering Society and academician of the USSR Scientific Correspondence, congratulated the Chinese delegates and collected the first time that China had made a 12,000 kW 3,000 rpm double-water internally cooled steam turbine generator with a 6,000 kW shaft and collected it in the meeting minutes and minutes. This is the first foreign report on China's first trial production of a double-water internally cooled steam turbine generator.

(1) It is necessary to strictly monitor the temperature of the static and rotating coil water, and the highest is generally 65-75. The increase in the temperature of the effluent is either caused by less water inlet or leakage, or by abnormal internal heating.

2) It should be noted that the static and rotor water pressure is within the specified range, because the pressure is closely related to the water flow rate and coil temperature. The cooling water of the rotor rod can not be interrupted, and the water is only allowed to run for 30 seconds. If the water cut-off protection is not put into operation, the generator should be disconnected immediately.

3) Frequently observe whether there is water leakage at the end, crack or flatten the insulated diversion pipe, loose parts, local overheating, condensation, etc.

4) Strengthen the monitoring of the temperature of each part and whether the stator wire rod is loose.

Both the stator and rotor are water-cooled generators, which are called dual water internal coolant generators. Under the action of the fans at both ends of the rotor, the air enters the air gap through the end of the stator winding, and then collects into the hot air area by the ventilation groove of the stator core, and after the cooling of the air cooler, it enters the negative pressure area of the fan from the air ducts on both sides to form the circulation of the air path.

The State Science and Technology Commission approved the establishment of a water-cooled motor research laboratory in Shanghai Electric Machinery Factory. At the end of 1963, the Ministry of Water and Power recognized the dual-water internally cooled steam turbine generator as a usable product.

On April 4, 1964, the Science and Technology Commission of the People's Republic of China issued a record of invention. It was determined that the invention units were Shanghai Electric Machinery Factory, Zhejiang University, Xiaoshan Electric Machinery Factory, the First Ministry of Machinery Industry Large Motor Research Institute, and Shanghai Nanshi Power Plant.

On February 10, 1965, the State Science and Technology Commission issued invention certificates to Shanghai Electric Machinery Factory, Zhejiang University and Nanshi Power Plant. However, due to the complete blockade of China by Western countries at that time, it was unable to apply for patents from relevant international organizations.