Repair of Damages that Occurred on the Welded Joints at the Body of Guide Vane Apparatus Vanes of the Vertical Kaplan Turbine

Vertical Kaplan turbines, with nominal power of 178 MW and manufactured in Russia, have been installed in 6 hydroelectric generating units of hydro power plant ’Djerdap 1’. Experimental tests were carried out by non-destructive methods in order to determine the turbine condition during the rehabilitation of the hydro power plant. Lack of root penetration was detected in V40 welded joints between upper and lower sleeves and bodies of guide vane apparatus vanes. Height of the lack of root penetration was in the range between 5 and 15 mm, while the allowable height of the lack of root penetration is 3 mm, according to the technical conditions. The upper sleeves were made of cast steel 25L (in accordance with GOST 977), while lower sleeves were made of steel forging St 25 (in accordance with standards GOST 1050 for chemical composition and GOST 8479 for forgings).Methodology for the repair of non-penetrated welded joints between the sleeves and body of the guide vane apparatus vane was composed taking into account the results of ultrasonic testing. By repair methodology it is necessary to, due to the structural solution and service function of guide vane apparatus vanes, specify a large number of details, consider them carefully and carry them out in order to improve safety, because if some of them get overlooked, underestimated or incorrectly perceived, significant problems in turbine operation may occur.This methodology refers solely to the repair of damaged welded joints between sleeves and bodies of guide vane apparatus vanes.

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Repair Welding Methodology for the Glasses of the Kaplan Turbine Runner at the Hydro Power Plant Djerdap 1

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1138.13 ◽

2016 ◽

Vol 1138 ◽

pp. 13-18 ◽

Cited By ~ 2

Author(s):

Miodrag Arsić ◽

Srđan Bošnjak ◽

Vencislav Grabulov ◽

Mladen Mladenović ◽

Zoran Savić

Keyword(s):

Power Plant ◽

Hydro Power ◽

Repair Welding ◽

Generating Sets ◽

Kaplan Turbine ◽

Turbine Runner ◽

Periodic Inspections ◽

Hydroelectric Generating Sets ◽

Non Destructive ◽

Structural Solutions

Vertical Kaplan turbines, manufactured in Russia and with nominal power of 200 MW, have been installed in 6 hydroelectric generating units at hydro power plant Djerdap 1. Hydroelectric generating sets have been designed for the service life of 40 years due to structural solutions and limited possibilities of performing periodic inspections and state analyses.During the rehabilitation of the hydroelectric generating sets, non-destructive tests were performed on all components and structures in order to complete state analysis. In this paper the damages and methodology of repair welding for damaged glasses, which are the integral part of the kinematic system of runner blades, are presented.

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Methodology for Reparation of Damaged Sleeves and Welded Shield Sections of Guide Vanes at Hydropower Plant DJERDAP 1

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1029.8 ◽

2014 ◽

Vol 1029 ◽

pp. 8-13

Author(s):

Miodrag Arsić ◽

Brane Vistać ◽

Srđan Bošnjak ◽

Vencislav Grabulov ◽

Zoran Savić

Keyword(s):

Guide Vane ◽

Cast Steel ◽

Experimental Tests ◽

Hydropower Plant ◽

Guide Vanes ◽

Surface Welding ◽

Turbine Shaft ◽

Welding Surface ◽

Continuous Use ◽

Non Destructive

Normal 0 false false false MicrosoftInternetExplorer4 Vertical Kaplan turbines, manufactured in Russia and with nominal power of 200 MW, have been installed in 6 hydroelectric generating units at ’Djerdap 1’. During the refurbishment of hydropower plant experimental non-destructive tests were performed in order to determine the state of turbine components. During the course of testing damage was detected at sleeves and welded shields of guide vanes, which occurred as a consequence of turbine shaft vibrations. 1782 mm long guide vane sleeves were made of cast steel 25L (GOST standard), 260 mm long sleeve was made of forged steel St 25 (GOST standard), while welded shields of guide vanes were made of austenitic steel 08X18H10T (GOST standard). Results of experimental tests and methodology for reparation of damaged surfaces of sleeves and welded shields of guide vanes are presented in this paper. It was necessary, due to the structural solution used for the design of guide vanes and their function during service, to define a large number of details, carefully reconsider them and carry out all activities with extreme care in order to enable the safe operation and continuous use of vanes through the use of reparation methodology for welding/surface welding of sleeves and welded shields. Overlooking, underestimation or incorrect perception of important details could cause significant problems during turbine operation. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

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State Analysis and Integrity of Welded Structures of the Upper Ring of the Turbine Runner Guide Vane Apparatus of Hydroelectric Generating Set A6 on Hydro Power Plant Djerdap 1

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.814.7 ◽

2013 ◽

Vol 814 ◽

pp. 7-18 ◽

Cited By ~ 2

Author(s):

Miodrag Arsić ◽

Zoran Odanovic ◽

Srdjan M. Bošnjak ◽

Mladen Mladenović ◽

Zoran Savić

Keyword(s):

Welded Joints ◽

Transverse Direction ◽

Magnetic Particle ◽

Guide Vane ◽

Base Material ◽

Metallic Inclusions ◽

Crack Type ◽

Turbine Runner ◽

Lamellar Tearing ◽

Non Destructive

During the refurbishment of the hydroelectric generating set A6 on HPP Djerdap 1, for the state analysis and assessment of the level and causes of degradation of the structure of the vertical Kaplan turbine runner guide vane apparatus non-destructive tests and inspections, as well as destructive tests of base material and welded joints, have been carried out after 40 years of service. Results of non-destructive tests performed on welded joints are presented in this paper (magnetic particle and ultrasonic inspection), as well as results of destructive tests of the base material and welded joints (testing of tensile properties, impact testing, metallographic analyses of the structure). A large number of crack type line indications were detected by magnetic particle inspections, while the occurrence of partial penetration in roots of welded joints was detected by ultrasonic inspections, as well as lamellar tearing of the base material. Tensile properties of tested samples taken in longitudinal and transverse direction fulfilled the requirements of the standard with certain deviations, which does not stand for samples taken in z-direction with significantly lower values of contraction of the cross-section than minimum prescribed values, which proves that base material is not resistant to the occurrence of lamellar cracks. Metallographic tests performed on specimens taken from the base material in longitudinal and transverse direction showed that the microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide, sulphide, silicate and aluminate type, while metallographic tests performed on specimens taken from welded joints showed that their microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide type. A large number of micro-and macro-cracks were detected in the microstructure as well. Experimental tests enabled the determination of the causes of occurrence of lamellar tearing in base material and crack type defects in welded joints, while analytical calculation that refers to the stress state enabled integrity of welded structure of the upper ring of the turbine runner guide vane apparatus.

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ALTERNATIVE METHOD OF NON-DESTRUCTIVE TESTING FOR NUCLEAR POWER PLANT

EPJ Web of Conferences ◽

10.1051/epjconf/202124711002 ◽

2021 ◽

Vol 247 ◽

pp. 11002

Author(s):

V.I. Surin ◽

A.I. Alwaheba ◽

V.G Beketov ◽

Abu Gazal

Keyword(s):

Welded Joints ◽

Control Method ◽

Operating Conditions ◽

The Body ◽

Practical Implementation ◽

Non Destructive Testing ◽

Steam Generators ◽

Destructive Testing ◽

Alternative Method ◽

Non Destructive

This study presents the results of electrophysical non-destructive testing of collectors welded joints to the body of steam generators PGV 1000Mof the reactor WWER-1000. The studied steam generators located in the Resource Сenter of National Research Nuclear University MEPhI at the site of reactors construction factory “Atommash” in Volgodonskcity-Russia. The primary loop collector was welded to the body of steam generators PGV 1000Mand the technical condition of welded joints was investigated by electrophysical non-destructive testing (EPhT). In steam generatorsmay appear corrosion and cracks due to corrosive environment and effect of stresses however,EPhTcan detect early stages of cracks. The study highlights the theoretical part of electrophysical diagnostics and control method, using modern mathematical signals analysis, and issues related to the practical implementation of EPhT in the factory. The novel alternative method of non-destructive testing can be used in diagnostic oil and gas pipelines, elements of complex technical structures and industrial equipment. It can be used in many industries where it is necessary to process control of the entire structure or its individual parts under operating conditions. Based on control results, potentiograms were constructed for various structural levels of the diagnostic signal. The results of controlled welded joints in steam generators showed their satisfactory condition.

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Results of Non-Destructive and Destructive Tests of Welded Joints Made of Heat-Resistant Cast Steel GX40NiCrSiNb35-25 in Welding Procedure Qualification

Biuletyn Instytutu Spawalnictwa ◽

10.17729/ebis.2017.2/4 ◽

2017 ◽

Vol 2017 (2) ◽

pp. 33-37

Author(s):

Sławomir Parzych

Keyword(s):

Welded Joints ◽

Cast Steel ◽

Heat Resistant ◽

Welding Procedure ◽

Non Destructive

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Main Provisions Of The Concept Of Technology Of Diamond Cutting And Drilling Of Building Structures

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.06.59-63 ◽

2019 ◽

pp. 59-63

Keyword(s):

Combustion Engine ◽

Front Surface ◽

The Body ◽

Building Structures ◽

Diamond Cutting ◽

Variable Diameter ◽

Diamond Drilling ◽

Single Structure ◽

New Construction ◽

Non Destructive

The main provisions of the concept of technology of diamond cutting and drilling of building structures are considered. The innovativeness of the technology, its main possibilities and advantages are presented. Carrying out works with the help of this technology in underwater conditions expands its use when constructing and reconstructing hydraulic structure. The use of diamond drilling equipment with motors equipped with an internal combustion engine is considered. Drilling holes with a variable diameter during the reconstruction of the runways of airfields makes it possible to combine the landing mats into a single structure. The ability to cut inside the concrete mass, parallel to the front surface, has no analogues among the methods of concrete treatment. The use of this technology for producing blind openings in the body of concrete without weakening the structure is also unique. Work with precision quality in cutting and diamond drilling of concrete and reinforced concrete was noted by architects and began to be implemented in the manufacture of inter-room and inter-floor openings. Non-destructive approach to the fragmentation of building structures allows them to be reused. The technology of diamond cutting and drilling is located at the junction of new construction, repair, reconstruction of buildings and structures, and dismantling of structures. Attention is paid to the complexity and combinatorial application of diamond technology. Economic efficiency and ecological safety of diamond technology are presented. The main directions of further research for the development of technology are indicated.

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Human reliability in non-destructive inspections of nuclear power plant components: modeling and analysis

Brazilian Journal of Radiation Sciences ◽

10.15392/bjrs.v7i2b.368 ◽

2019 ◽

Vol 7 (2B) ◽

Author(s):

Vanderley Vasconcelos ◽

Wellington Antonio Soares ◽

Raissa Oliveira Marques ◽

Silvério Ferreira Silva Jr ◽

Amanda Laureano Raso

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Human Factors ◽

Nuclear Power ◽

Power Plants ◽

Failure Modes ◽

Cooling System ◽

Human Reliability ◽

Non Destructive ◽

Plant Components

Non-destructive inspection (NDI) is one of the key elements in ensuring quality of engineering systems and their safe use. This inspection is a very complex task, during which the inspectors have to rely on their sensory, perceptual, cognitive, and motor skills. It requires high vigilance once it is often carried out on large components, over a long period of time, and in hostile environments and restriction of workplace. A successful NDI requires careful planning, choice of appropriate NDI methods and inspection procedures, as well as qualified and trained inspection personnel. A failure of NDI to detect critical defects in safety-related components of nuclear power plants, for instance, may lead to catastrophic consequences for workers, public and environment. Therefore, ensuring that NDI is reliable and capable of detecting all critical defects is of utmost importance. Despite increased use of automation in NDI, human inspectors, and thus human factors, still play an important role in NDI reliability. Human reliability is the probability of humans conducting specific tasks with satisfactory performance. Many techniques are suitable for modeling and analyzing human reliability in NDI of nuclear power plant components, such as FMEA (Failure Modes and Effects Analysis) and THERP (Technique for Human Error Rate Prediction). An example by using qualitative and quantitative assessesments with these two techniques to improve typical NDI of pipe segments of a core cooling system of a nuclear power plant, through acting on human factors issues, is presented.

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