Experimental researches of thermal hydraulic characteristics in the model of sodium-air heat exchanger for fast reactor emergency cooling system
Results of experimental researches of thermohydraulic characteristics in the bundle of finned tubes are presented in the paper. The test section represents a fragment of flow part of sodium-air heat exchanger in the emergency cooling system of a fast reactor, with sodium flow inside the tubes and cooled by lateral flow of air. A great data array of temperature values on the finned tubes surface at different air velocities and hydraulic characteristics of finned tube bundle were gained.Experimental data on heat transfer were processed in two ways: first, on the basis of direct measurements of temperatures on the surface of a finned tube and air flow and, secondly, on mean value of heat transfer coefficient of tube bundle. Analysis of experimental data has shown that a divergence of both approaches does not exceed 19%. It was found in the tests that the heat flow removed from a finned tube’s surface with a finned surface factor being equal to 7.2 is 3-5 times more intensive than that from smooth surface. In the course of the experiments air overheating was noticed in the intertubularspace in the direction of air flow. Most likely, it is due to formation of stagnant zones caused by small interfin spaces and heat accumulationduring long warming up of the sodium circuit.Experimental data can be used for verification of thermal hydraulic numerical codes for sodium-air heat exchanger in the emergency cooling system of fast reactors. The experimental results application to a full-scale facility is substantiated. Power estimations of a full-scale heat made with regard to the value of experimental heat transfer coefficientshave shown that heat removalcan be lower (depending on the velocity of air flow) than claimed in the design.
- Zverev D.L., Vasil’ev B.A., Sedakov V.Yu., Kuzavkov N.G. Osvoenie tehnologii bystryh natrievyh reaktorov. Sozdanie RU BN-800 [Mastering the technology of fast sodium reactors.Creation of BN-800]. Izvestiya vuzov. Yadernaya energetika. 2011, no. 2, pp. 130–142.
- Efanov A.D., Sorokin A.P., Matjuhin N.M., Chernonog V.L. The experimental base of SSC RF-IPPE for research of liquid metals heat and mass transfer. Hydrodynamics and heat transfer in reactor components cooled by liquid coolant in single / two-phase (working material), IAEA. TWG-FR/125. Vienna, Austria. 2005, pp. 8–25.
- Zhukauskas A.A. Konvektivnyj perenos v teploobmennikah [Convective transfer in heat exchangers]. Moskow, Nauka Publ. 1982.
- Miheev M.A. Raschetnye formuly konvektivnogo teploobmena [Convective heat exchande calculation formulas]. Izvestiya AN SSSR. Energetika i transport. 1966, no. 5, pp. 95–105.
- Isachenko V.P. – V kn.: Teploperedacha i teplovoe modelirovanie [In the book «Heat transfer and thermal modeling»]. Moskow, AN SSSR Publ. 1959, pp. 213–225. (in Russian)
- Isachenko V.P., Salom-Zade F.G. Teplootdacha v koridornyh puchkah poperechno omyvaemyh gladkih trub [Heat exchange at the corridor bundles of smooth tubes with transverse flushing]. Teploenergetika. 1969, no. 5, pp. 84–87.
- Metodika i zavisimosti dlya teoreticheskogo rascheta teploobmena i gidravlicheskogo soprotivleniya oborudovaniya AES (RTM 24.031.05#72) [Methodology and dependencies for theoretical calculation of heat exchange and hydraulic resistance of NPP equipment (RTM 24.031.05-72).]. Moskow, Ministerstvo tyazhelogo, energeticheskogo i transportnogo mashinostroeniya Publ. 1974.
- Kutateladze S.S. Osnovy teorii teploobmena [Fundamentals of the theory of heat exchange]. Novosibirsk. Nauka Publ. 1970.
- Yudin V.F. Teploobmen v orebrennyh puchkah [Heat exchange of the finned bundles]. Leningrad, Energiya Publ. 1980.
- Schmidt H.T. Der Wдrmeьbergang an Rippenrohre und die Berechnung von Rohrbьndel Wдrmeaustau – Schern. – Kдltetechn. – 1963. – Bd. 15. – H. 4. – pp. 98-102. – H. 12. – pp. 370-378.
- Kirillov P.L., Yur’ev Yu.S., Bobkov V.P. Spravochnik po teplogidravlicheskim raschetam [Handbook of thermohydraulic calculations]. Moskow, Energoatomizdat Publ. 1990.