Steam Turbine Blade Manufacturer Introduces Blade for You

2018-11-23 13:57:26 admin 101

Steam Turbine Blade Manufacturer Introduces Blade for You

Blade is the key part of steam turbine, and one of the most precise and important parts. It withstands the combined action of high temperature, high pressure, huge centrifugal force, steam force, steam excitation force, corrosion and vibration, and water droplet erosion in wet steam zone under extremely harsh conditions. Its aerodynamic performance, processing geometry, surface roughness, installation clearance and operating conditions, scaling and other factors all affect the efficiency and output of the steam turbine, while its structural design, vibration intensity and operation mode have a decisive impact on the safety and reliability of the unit. Therefore, the world's most famous manufacturing groups have unremittingly made great efforts to apply the most advanced scientific and technological achievements to the development of new blades, and constantly introduce new blades with better performance than the next generation, in order to safeguard their advanced position in the field of steam turbine manufacturing.
From 1986 to 1997, China's electric power industry has been developing continuously and rapidly. Power plant steam turbines are realizing high parameters and large capacity. According to statistics, by the end of 1997, the installed capacity of steam turbines, including thermal power and nuclear power, had reached 192 GW, including 128 thermal power 250-300 MW units, 29 320.0-362.5 MW units, 17 500-660 MW units, and 188 200-210 MW units, 123 110-125 MW units and 100 MW units. Group 141. The maximum capacity of nuclear power steam turbine is 900MW.
With the large capacity of steam turbines in power plants in China, the safety and reliability of blades and the maintenance of their high efficiency are becoming more and more important. For 300 MW and 600 MW units, the power conversion of each stage blade is as high as 10 MW or even 20 MW. Even if the blade is slightly damaged, the reduction of thermal economy and safety reliability of the steam turbine and the whole thermal power unit can not be ignored. For example, because of scaling, the area of nozzle in the first stage of high pressure will be reduced by 10%, and the output of the unit will be reduced by 3%. Because of the damage of blade caused by hard foreign bodies and the damage of blade eroded by solid particles, the efficiency of the stage may be reduced by 1%-3% depending on the severity of the damage. If the blade breaks, the consequences are: light vibration and flow of the unit will be caused. Partial dynamic and static friction, and loss of efficiency; serious will cause forced shutdown, sometimes for the replacement of blades or repair of damaged rotors and stators take weeks to months; in some cases, due to blade damage is not found in time or timely treatment, causing the accident to expand to the whole unit or due to the last blade fracture. It is not uncommon at home and abroad to cause unbalanced vibration of generating units, which may lead to the destruction of the whole unit, and its economic losses will be billions of dollars.
Experience accumulated over the years has proved that whenever a large number of new type steam turbines are put into operation or when the power supply and demand imbalance occurs when the steam turbines deviate from the design conditions for a long time, the blade failure damage caused by design, manufacture, installation, maintenance and improper operation will be fully exposed. As mentioned above, the installation of large steam turbines in power plants in China has been increasing rapidly for more than 10 years, and new situations of long-term low-load operation of large turbines in some areas have begun to emerge. Therefore, it is necessary to investigate, analyze and summarize all kinds of damage of blades, especially the last stage and regulating stage blades, and to find out the rules in time so as to formulate the rules. Prevention and improvement measures to avoid large losses