EDN: IEIJRG
Authors & Affiliations
Pisarevsky M.I., Mohiuddin S., Golyaev D.I., Fedoseev V.N.
National Research Nuclear University “MEPhI”, Moscow, Russia
Pisarevsky M.I. – Senior Lecturer. Contacts: 31, Kashirskoe shosse, Moscow, 115409. Tel.: +7 (495) 788-56-99; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Mohiuddin S. – Master's Degree.
Golyaev D.I. – Graduate Student.
Fedoseev V.N . – Associate Professor, Cand. Sci. (Tech.).
Abstract
During the operation of the NPP power equipment, a natural roughness is formed on the heat exchange surfaces, which can serve as reasons for reducing the coolant flow rate due to an increase in friction resistance. The article proposes a method for estimating the size of sediments on structural elements in units of equivalent sand roughness. The movement of a coolant in a narrow annular channel with one rough wall is considered, since it is a simulation model of an equivalent cell of a fuel element. The channel is divided into two layers by a line of zero shear stresses. Each layer has its own thickness, the average speed of the coolant, the law of change of the hydraulic resistance coefficient. A formula is obtained for calculating the coefficient of hydraulic resistance of a rough layer, according to the size of sediments is determined. Validation of the methodology was carried out on three artificial roughness and one natural roughness created by a sandblasting machine. Two-dimensional rectangular, trapezoidal and triangular protrusion are considered as artificial roughness. The difference between the calculated values of the equivalent sand roughness from the reference does not exceed 20 %. The dependences of the pressure drop growth along the length of the annular channel on the size of the equivalent sand roughness are drawn in graph for fixed Reynolds numbers. This dependence on the measured pressure drop allows us to determine the size of the protrusions of sediments.
Keywords
roughness, natural roughness, artificial roughness, equivalent sand roughness, deposits, hydraulic resistance coefficient, annular channel, rectangular channel, rough layer
Article Text (PDF, in Russian)
References
1. Trofimov M.A., Globa R.B. Zavisimost' sherokhovatosti vnutrenney poverkhnosti truboprovodov yadernykh reaktorov ot sroka ikh ekspluatatsii [Dependence of the roughness of the inner surface of pipelines of nuclear reactors on their service life]. Izvestiya vuzov. Yadernaya energetika, 2019, no. 3, pp. 88–95. DOI: 10.26583/npe.2019.3.08.
2. Sharov V.A. Ul'trazvukovaya ochistka toplivnykh kaset VVER na primere energoblokov № 3 i № 4 Novovoronezhskoy AES. Diss. … kand. tech. nauk [Ultrasonic cleaning of WWER fuel caskets on the example of power units No. 3 and No. 4 of the Novovoronezh NPP. Cand. tech. sci. diss.]. Moscow, 2015. 249 p.
3. Idelchik I.E. Spravochnik po gidravlicheskim soprotivleniyam [Handbook of hydraulic resistances]. Moscow, Mashinostroyeniye Publ., 1992. 671 p.
4. Ibragimov M.H., Subbotin V.I., Bobkov V.P., Taranov G.S., Abelev G.I. Struktura turbulentnogo potoka i mekhanizm teploobmena v kanalakh [Structure of turbulent flow and mechanism of heat exchange in channels]. Moscow, Atomizdat Publ., 1978. 294 p.
5. Korsun A.S., Kutsenko K.V., Pisarevsky M.I., Fedoseev V.N., Balberkina Y.N. Hydraulic resistance of plane channels and annulus with different roughness on opposite walls. Thermal Engineering, 2017, vol. 64, no. 3, pp. 234–236. DOI: 10.1134/S0040601517020045.
6. Petukhov B.S., Genin L.G., Kovalev S.A. Teploobmen v yadernykh energeticheskikh ustanovkakh [Heat transfer in nuclear power plants]. Moscow, Energoatomizdat Publ., 1986. 233 p.
7. Tarasevich S.E., Zlobin A.V., Yakovlev A.B. Hydrodynamics and heat transfer in single-phase fluid flows in artificially rough pipes. High Temperature, 2015, vol. 53, pp. 908–920, DOI: 10.1134/S0018151X15060206.
8. Ugolev R.I., Bobkov V.P., Smogeli I.P. Rukovodstvo po bezopasnosti RB-075-12 [Security Guide RB-075-12]. 2012, pp. 1–150.
9. Kirillov P.L., Yuryev Y.S., Bobkov V.P. Spravochnik po teplogidravlicheskim raschetam (yadernyye reaktory, teploobmenniki, parogeneratory) [Handbook of thermohydraulic calculations (nuclear reactors, heat exchangers, steam generators)]. Moscow, Energoatomizdat Publ., 1990. 360 p.
10. Kader B.A. Teplo- i massoperenos ot stenok, pokrytykh dvumernoy sherokhovatost'yu, pri bol'shikh chislakh Reyonol'dsa i Pekle. [Heat and mass transfer from walls covered with two-dimensional roughness at high Reynolds numbers and Bake]. Teoreticheskiye osnovy khimicheskikh tekhnologiy – Theoretical Foundations of Chemical Technologies, 1979, vol. XIII, no. 5, pp. 663–675.
UDC 532.542.4
Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2022, no. 4, 4:15
