A method for anti-scouring, anti-abrasion, and bursting of high-temperature and high-pressure drainage pipelines in thermal power plants

Abstract

The invention discloses a high-temperature and high-pressure drain pipeline anti-scouring and anti-wear pipe bursting technology for a thermal power plant. The high-temperature and high-pressure drainpipeline anti-scouring and anti-wear pipe bursting technology for the thermal power plant concretely comprises the following technologies of 1) establishing a drain pipeline steam-water two-phase three-dimensional model based on a CFD-DEM fluid calculation method, and obtaining internal detail characteristics, including temperature field distribution, steam-liquid mass distribution and steam-liquid flow velocity distribution; and 2 ) transformation on the drain pipeline, comprising the following steps of 2.1) mounting a throttling nozzle at the tail end of a main steam drain pipeline, and adopting calculation data of a CFD-DEM three-dimensional calculation unit as reference for determining design parameters of the throttling nozzle; and 2.2) performing wear-resisting treatment on a bent pipe in the drain pipeline and a connecting flange of the drain pipeline and the main steam pipeline. The high-temperature and high-pressure drain pipeline anti-scouring and anti-wear pipe bursting technology for the thermal power plant can effectively lower erosive wear of a working medium in the drain pipeline to the pipeline, improves the anti-scouring capability of the drain pipeline, lowers the risk of pipe bursting of the drain pipeline and improves the safety of a unit.

Description

technical field [0001] The invention relates to a method for anti-scouring, anti-abrasion and bursting of a high-temperature and high-pressure drain pipeline in a thermal power plant, and belongs to the technical field of safety technology for a steam turbine system in a thermal power plant. Background technique [0002] When the steam turbine unit of a thermal power plant is started, shut down and operated under variable load conditions, the steam is in contact with the steam turbine body and steam pipes, and the steam is cooled. When the temperature of the steam is cooled below the saturation temperature corresponding to its pressure, part of the steam will condense into water to form a drain, and the drain must be discharged through the drain in time, otherwise it will cause a series of serious problems and consequences, mainly as follows Aspects: [0003] (1) In the main steam pipeline, if there is drainage, due to the different density and flow velocity of steam and wa...

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Problems solved by technology

[0003] (1) In the main steam pipeline, if there is drainage, due to the different density and flow velocity of steam and water, the resistance of the pipeline to them is also different. This part of the condensed water may cause water impact, and at least the pipeline will vibrate. It produces huge noise and pollutes the environment; in severe cases, the main steam pipeline will be cracked or even ruptured, causing the unit to be forced to stop

[0004] (2) Once the drainage of the main steam pipeline enters the steam turbine, the moving blades of the steam turbine will be damaged by the impact of water, or even break; the rapid cooling of metal parts will cause a large thermal stress, and the asymmetrical thermal stress will cause large shaft bending, or even permanent deformation

[0005] (3) For high-temperature and high-pressure drainage pipelines, due to the continuous erosion of high-temperature and high-pressure steam and drainage, frequent wear, leakage and burst accidents of drainage pipelines seriously threaten the safety of personnel and equipment, and are forced to shut down

[0008] At present, the treatment of high-temperature and high-pressure drainage pipelines is only through the replacement of pipelines and valves, which is not an effective solution. An effective solution has not been proposed from the mechanism of soda-water mixture on pipelines and valves. And it needs to consume a lot of manpower and material resources, the economy is poor, and there is a huge potential safety hazard.

Through research and novelty research, there is no good treatment technology and solution for the problem of pipe wear and burst in high-temperature and high-pressure drainage systems at home and abroad, and it is urgent to propose a more feasible solution

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