Turbine and turbine troubleshooting and oil purification equipment parameters
2019/12/8??????view:
Hydraulic lubrication system is an important part of steam turbine, its working condition directly affects the safe and economic operation of the unit. Accidents of unit failure and equipment damage caused by turbine oil filter system occur frequently, especially in the stage of capital construction and commissioning.
Steam turbine, also known as steam turbine engine, is a kind of rotating steam power device. High temperature and high pressure steam passes through the fixed nozzle to become an accelerated air flow, and then is sprayed on the blade, so that the rotor equipped with blade row rotates and works externally at the same time. Steam turbine is the main equipment of modern thermal power plant, which is also used in metallurgical industry, chemical industry and ship power plant.
Water turbine (explanation of terms) is a power machine that converts the energy of water flow into the energy of rotating machinery. It belongs to the turbine machinery in fluid machinery. As early as around 100 BC, the rudiment of water turbine appeared in China - water turbine, which is used to lift irrigation and drive grain processing equipment. Most of the modern turbines are installed in hydropower stations to drive generators to generate electricity. In the hydropower station, the water in the upstream reservoir is led to the turbine through the diversion pipe, which drives the turbine runner to rotate and drives the generator to generate electricity. The finished water is discharged to the downstream through the tailrace pipeline. The higher the head and discharge, the greater the output power of the turbine.
The following introduces several faults and causes of turbine oil filter system in the stage of capital construction and commissioning.
1. Fault phenomena and causes
1.1 fault caused by poor oil quality
Poor oil quality mainly refers to that the water content, particle size and other indicators in the oil exceed the specified standards. For example, during the shutdown and defect elimination of unit 1 (300MW) of a power plant in January 1996, the oil in the main oil tank was poured into the oil storage tank, and the equipment was damaged due to the lubricating oil pollution caused by the unclean oil storage tank. In November of the same year, during the commissioning of No. 2 unit (300MW) of the plant, the servo valve and dump valve of the intermediate pressure main throttle valve were stuck and the throttle hole of the servo mechanism was blocked due to the poor oil quality for many times. In January 1997, the unit 13 (125MW) of a power plant appeared the phenomenon of middle door clamp and low lubricating oil pressure during the on load commissioning, which were all caused by oil dirt after inspection. After the tile was removed, the Journal of the unit was damaged and the bearing bush was roughened.
There are two main reasons for the poor oil quality: first, the manufacturing quality is not good, and the oil quality is unqualified when it leaves the factory; second, it is polluted by the outside world.
1.2 failure caused by poor equipment quality
Poor quality of equipment refers to that the process of processing and manufacturing of equipment and accessories is not carried out according to relevant regulations, resulting in the quality not meeting the standard requirements. The poor quality of the equipment is one of the main reasons for the failure of the oil system. For example, during the shutdown inspection of No.1 unit (300MW) of a power plant in January 1996, it was found that the paint on the inner wall of the main oil tank had fallen off, causing the deterioration of oil quality and wearing the turbine journal and bearing bush (the inner wall of the main oil tank was not treated as required). In November of the same year, due to the unclean inside of the sealing oil device of unit 2 (300MW), 14 valve shells were seriously rusted, which caused oil system pollution, not only affected the normal operation of the sealing oil system and the commissioning of the unit, but also caused equipment damage. In October 1996, No. 5 unit (300MW) of a power plant was shut down and stripped after the first complete set of start-up. No. 4 bearing bush was roughened and its journal was scratched. Further inspection found that the quality of sealing oil system valve was poor and there were many impurities (rust, iron chips, etc.) left inside, resulting in the pollution of sealing oil and lubricating oil system and equipment damage.
The above two accidents caused by the sealing oil system are all caused by the failure of careful quality inspection before the equipment leaves the factory, resulting in the failure to find and solve the problems in time.
1.3 faults caused by other reasons
In addition to the poor oil quality and equipment quality, the poor installation process and technical measures are also the main causes of oil system failure. For example, during the trial operation of unit 1 (125MW) of a power plant in September 1989, "the pressure at the inlet and outlet of the main oil pump was low", which was found to be caused by the reversed installation of the fire door of the oil system and the nozzle of the oil injector. In December 1995, after 72h test run of unit 3 (300MW) of a power plant, it was found that No.2, No.3 and No.
2. Countermeasures and measures
From the above fault phenomena, we can see that in order to prevent the occurrence of oil system accidents, we must start from the manufacturing, installation, operation and other aspects of the equipment. In order to ensure the safe and economic operation of the equipment, we need not only excellent manufacturing and installation technology, but also perfect technical measures.
2.1 strictly control the equipment quality to ensure the safe operation of the equipment
Good equipment quality is the basis of safe and economic operation. Without quality assurance, safe operation cannot be talked about. Therefore, on the one hand, under the premise of strengthening internal management, equipment manufacturers need to continuously improve the level of production technology, strictly control the quality of equipment, and prevent unqualified products from being put into production and operation; on the other hand, users should also send personnel to the factory for supervision during equipment manufacturing to ensure that the quality and quantity meet the requirements.
2.2 improve process level to ensure equipment installation quality
Excellent installation technology is the guarantee of safe operation of the equipment. Before installation, the equipment must be disassembled, inspected and cleaned on site, and the oil pipeline must be chemically cleaned; in the process of equipment installation, attention should be paid not only to the impact of environmental factors, but also to the technological level of equipment installation. The installation of the oil system has a high process standard, such as the welding of the oil pipeline, the treatment of the inner wall of the oil tank, the installation of various equipment of the oil system and other process requirements are clearly specified in the specification
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