DEVELOPMENT OF NEW STRUCTURAL EVELOPMENT OF NEW STRUCTURAL ELEMENTS OF GAS COOLERS LEMENTS OF GAS COOLERS IN ATOMIC AND THERMAL POWER N ATOMIC AND THERMAL POWER PLANTS WITH IMPROVED LANTS WITH IMPROVED CORROSION-MECHANIC RESISTANCE
Keywords:gas cooler, pipe board, copper tubes, crevice corrosion, hydrogenation, turbogenerator.
Introduction. In power engineering, there is a need to improve the performance of gas coolers in contact with explosive atmospheres to ensure reliable operation of turbogenerators.
Problem Statement. Important problems that require constant improvement of equipment are local corrosion, hydrogenation, etc., in particular, of pipe joints with pipe boards, which is characterized by the emergence and development of cracks under the influence of simultaneous mechanical stress and corrosive environment. The
cracks promote depressurization that leads to emergency stop of turbogenerator.
Purpose. To develop a new design of sealing joints of heat exchange tubes and tube sheet with increased corrosion and corrosion-mechanical resistance.
Materials and methods. The samples made of steel 09G2S, M2 copper, steel 09G2S with a clad layer of copper M2, cupronickel МNZhМC 30-1-1, brass L68 have been tested. The vacuum extraction of hydrogen under elevated temperature, corrosion-fatigue, metallographic, and X-ray spectral test methods have been used.
Results. A new structural element of gas coolers with improved characteristics has been designed. It is based on a welded-rolled joint of a copper tube with a copper-clad tube sheet, which does not cause deformation of the structure and crack formation. The studies of the effect of different modes of flaring of such joints on their resistance to failure under the simultaneous action of cyclic loads and the environment have shown that as the degree of flaring of copper tubes 19 1.5 and 19 1 mm increases, the crack generation period and durability combined with connections grows ~1.5 times.
Conclusions. The new structural element reduces the probability of corrosion and mechanical destruction of parts of heat exchange equipment and helps to extend the period of its trouble-free operation.
Technical requirements and delivery conditions. Gas coolers of the ТВВ-1000-4У3. turbogenerator. 123456.ЭЦ.GT.
TT.68-67. (2017). Ministry of Energy and Coal Industry of Ukraine. State Enterprise “National Atomic Energy Generating Company”. Energoatom “SE” Zaporizhzhya NPP “. Energodar [in Ukrainian].
Hydrogen in metals: in 2 volumes. (1981). (Eds. G. Alefeld and I. Felkle). Moscow: Mir [in Russian].
Khoma, M. C. (2003). Theoretical bases of an initial stage of corrosion-fatigue cracking of steels and alloys and development of methods of forecasting of their limits of endurance (Doctoral dissertation) (Tech. Science) [in Ukrainian].
СОУ МПП 71.120-217:2009 (2009). Welded steel vessels and apparatus. General technical conditions. Kyiv [in Ukrainian].
State Standart of Ukraine 3-071-2004. (2004). Shell and tube heat exchangers and air cooling devices. Fastening of pipes in pipe lattices. Kyiv [in Ukrainian].
Narivskyy, O., Belikov, S., Khoma, M., Datsko, B., Guravskyy, M., Shtayra, S. (2020). Ensuring the reliability of the sealing of heat transfer tubes in the tube grids of heat exchangers. Phys.-chem. mechanics of materials. Spec. issue, 13, 321—325 [in Ukrainian].
Narivskyy, O., Belikov, S., Mardarevich, R., Ivashkiv, V., Guravskyy, M., Rudkovskyy, E., Chuchman, М. (2020). Increasing the durability of gas coolers of the ТВВ-1000-4У3 turbogenerator. Phys.-chem. mechanics of materials. Spec. issue, 13, 326—331 [in Ukrainian].
Ryabov, V. R., Rabkin, D. M., Kurochko, R. S., Strizhevskaya, L. G. (1984). Welding of dissimilar metals and alloys. Moscow: Mashinostroenie [in Russian].
Levitskyy, M. O., Kalichak, T. N., Zaverbny, D. M., Pokhmurskyy, V. I. (1981). Machine for fatigue testing of flat samples under conditions of soft and hard loading. Phys.-chem. mechanics of materials, 17(6), 116—117 [in Russian],
Pachurin, G. V. (2014). Structural damage and fatigue resistance of technically pure copper. Int. Journal of Applied and Fundamental Research, 2—2, 22—27 [in Russian].
How to Cite
Authors published in the journal “Science and Innovation” agree to the following conditions:
Authors retain copyright and grant the journal the right of first publication.
Authors may enter into separate, additional contractual agreements for non-exclusive distribution of the version of their work (article) published in the journal “Science and Innovation” (for example, place it in an institutional repository or publish in their book), while confirming its initial publication in the journal “Science and innovation.” Authors are allowed to place their work on the Internet (for example, in institutional repositories or on their website).