TY - JOUR AU - Varju, Tamás AU - Csige, András AU - Kiss, Attila AU - Filonov, V. AU - Filonova, Y. AU - Fedorov, D. AU - Pucciarelli, A. AU - Kassem, S. AU - Ambrosini, W. TI - Discussion and perspectives for improvements of heat transfer correlation capabilities for fluids at supercritical pressures JF - NUCLEAR ENGINEERING AND DESIGN J2 - NUCL ENG DES VL - 421 PY - 2024 PG - 23 SN - 0029-5493 DO - 10.1016/j.nucengdes.2024.113085 UR - https://m2.mtmt.hu/api/publication/34735228 ID - 34735228 N1 - Budapest University of Technology and Economics, Hungary IPP-Centre LLC, Ukraine Università di Pisa, Italy Export Date: 22 March 2024 CODEN: NEDEA Correspondence Address: Pucciarelli, A.; Università di PisaItaly; email: andrea.pucciarelli@unipi.it Funding details: Xi'an Eurasia University, EU Funding details: H2020 Euratom, 945234 Funding text 1: The work presented in this paper was performed in the frame of the EU ECC-SMART project (Joint European Canadian Chinese Development of Small Modular Reactor Technology). This project received funding from the Euratom research and training programme 2019–2020 under grant agreement no. 945234. LA - English DB - MTMT ER - TY - CHAP AU - Kiss, Attila ED - anon., anon. TI - TWO CFD BENCHMARKS FOR TUBE AND ANNULUS GEOMETRIES T2 - Understanding and Prediction of Thermohydraulic Phenomena Relevant to Supercritical Water Cooled Reactors (SCWRs) PB - International Atomic Energy Agency (IAEA) CY - Vienna SN - 9789201024206 T3 - IAEA-TECDOC ; 1900. PY - 2020 SP - 375 EP - 399 PG - 25 UR - https://m2.mtmt.hu/api/publication/31818516 ID - 31818516 LA - English DB - MTMT ER - TY - CHAP AU - Kiss, Attila ED - anon., anon. TI - OVERVIEW OF PAST EXPERIMENTAL WORKS ON HEAT TRANSFER OF SCW FLOW IN TUBES T2 - Understanding and Prediction of Thermohydraulic Phenomena Relevant to Supercritical Water Cooled Reactors (SCWRs) PB - International Atomic Energy Agency (IAEA) CY - Vienna SN - 9789201024206 T3 - IAEA-TECDOC ; 1900. PY - 2020 SP - 38 EP - 43 PG - 6 UR - https://m2.mtmt.hu/api/publication/31818496 ID - 31818496 LA - English DB - MTMT ER - TY - JOUR AU - Kiss, Attila AU - Mervay, Bence TI - Further Details of a Numerical Analysis on the Thermal Hydraulic Effect of Wrapped Wire Spacers in Fuel Bundle JF - JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE J2 - J NUCLEAR ENG RAD SCI VL - 6 PY - 2020 IS - 3 PG - 10 SN - 2332-8983 DO - 10.1115/1.4046842 UR - https://m2.mtmt.hu/api/publication/31448845 ID - 31448845 AB - The application of relatively simple and cheap wrapped wire spacer in the European supercritical water-cooled reactor (SCWR) (high-performance light water reactor (HPLWR)) has been proposed in order to provide enhanced heat transfer in the fuel assembly without unacceptable penalty in pressure loss. The wires cause twisting flow in the fuel assembly, which means the coolant not only flows straight in the axial direction but also has a significant transverse velocity component, and strong mixing between neighboring subchannels occurs. The aim of this ongoing research is to numerically investigate the effect of wrapped wire spacers on thermal hydraulics of the turbulent coolant flow and its heat transfer in a small bundle of four fuel rods. One bare and six-wired geometries with varying wire pitches (1-6 turn(s) of wires) have been studied. It was found that the wires generate significant amount of transverse velocity, decrease the wall temperature, and increase the heat transfer coefficient mostly in corner subchannels which were the hottest in bare geometry. Thus, the presence of wires enhances heat transfer where it is most needed. Temperature hot spots with moderate values have been identified on the cladding wall of fuel rods. Based on the results, a technically optimal choice of number of wire turns from thermal hydraulic sense has been proposed. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, Attila AU - Hegyesi, Bela AU - Ujváry, Patrik Richárd AU - Ványi, András Szabolcs AU - Csom, Gyula TI - About the Thermal Hydraulic Analysis Part of a Coupled Study on a Thorium-Fueled SCWR Concept JF - JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE J2 - J NUCLEAR ENG RAD SCI VL - 6 PY - 2020 IS - 3 PG - 12 SN - 2332-8983 DO - 10.1115/1.4046904 UR - https://m2.mtmt.hu/api/publication/31448267 ID - 31448267 AB - Inherently poorer moderation in supercritical water-cooled reactors (SCWRs) due to average density lower than in light water reactors and the resulted spectral shift can be useful when we apply thorium fuel-cycle instead of uranium-plutonium one, according to an ongoing study in Budapest University of Technology and Economics (BME) Institute of Nuclear Techniques (NTI). Upon this conclusion, a thorium-fueled SCWR design (Th-SCWR) has been proposed by BME NTI. In the current feasibility study phase, detailed three-dimensional (3D) computational fluid dynamics (CFD) calculations with novel neutronics analysis were coupled and conducted separately. Neutronics calculations provided the distribution of heat source, while the CFD analysis gave back axial distribution of coolant density (this iteration was repeated until an acceptable convergence). This paper presents the CFD analysis on thermal hydraulics of the initial design (two CFD models without any spacer device and one model with wrapped wire spacer) of Th-SCWR fuel assembly. As results of the preliminary design of Th-SCWR cladding wall, coolant and fuel temperatures have been determined; the flow field with and without spacer device has been showed, and the application of wrapped wire spacer has been proposed. LA - English DB - MTMT ER - TY - JOUR AU - Kiss, Attila AU - Mervay, Bence TI - Numerical analysis on the thermal hydraulic effect of wrapped wire spacer in a four rod fuel bundle JF - NUCLEAR ENGINEERING AND DESIGN J2 - NUCL ENG DES VL - 342 PY - 2019 SP - 276 EP - 307 PG - 32 SN - 0029-5493 DO - 10.1016/j.nucengdes.2018.11.024 UR - https://m2.mtmt.hu/api/publication/30511130 ID - 30511130 AB - The application of relatively simple and cheap wrapped wire spacer in the European supercritical-water-cooled reactor has been proposed in order to provide enhanced heat transfer in the fuel assembly without unacceptable penalty in pressure loss. The wires cause twisting flow in fuel assembly, which means the coolant flows not only straight in the axial direction but has a significant transverse velocity component and strong mixing between neighbouring sub-channels occurs. The aim of this ongoing research is to numerically investigate the effect of wrapped wire spacers on thermal hydraulics of turbulent coolant flow and its heat transfer in a small bundle with four fuel rods. One bare and six wired geometry with different wire pitches (1-6 turn(s) of wires) have been studied. Unstructured volume mesh of tetrahedral elements with fine near wall boundary mesh of prism elements for fluid domain and structured mesh of hexahedral elements for solid domains of fuel rods, wires, etc. have been used to discretize the computational domain. After an extensive mesh and turbulence model sensitivity study, the M4 mesh resolution and the most advanced BSL Reynolds Stress turbulence model were selected for the further CFD calculations. The validation of the model with 3 turns of wires has been performed. The wires generate significant amount of transverse velocity and decrease the wall temperature most in corner subchannels which was hottest in bare geometry. The heat transfer coefficient has been increased also most in corner sub-channels by 60-145% depending on the number of turns of wires. The other two types of sub-channel showed moderated (wall type) or negligible (central type) decrease in wall temperature and enhancement in heat transfer. Temperature hot spots with moderate values have been identified on the wall of fuel rods. The optimal technical choice from thermal hydraulic sense seems to be three turns of wires due to the pressure drop is only 18% higher than in bare geometry but maximum wall temperature is 32 degrees C lower while the average heat transfer coefficient is 95% higher where it is most needed, in the corner sub-channels. For these thermal benefits, the 18% penalty in the pressure drop seems to be acceptable. The outcome of this technical optimization needs further confirmation by an economic analysis while the possible long term effect of revealed hot spots on integrity of fuel rod cladding has to be investigated as well. LA - English DB - MTMT ER - TY - THES AU - Kiss, Attila TI - Thermal hydraulic investigations of the coolant flow in Supercritical Water-cooled Reactor relevant geometries PB - Budapesti Műszaki és Gazdaságtudományi Egyetem PY - 2018 UR - https://m2.mtmt.hu/api/publication/31347384 ID - 31347384 N1 - Egyéni felkészülő LA - English DB - MTMT ER - TY - JOUR AU - Kiss, Attila AU - Churkin, A AU - Pilkhwal, DS AU - Vaidya, AM AU - Ambrosini, W AU - Pucciarelli, A AU - Podila, K AU - Rao, YF AU - Leung, L AU - Chen, YZ AU - Anderson, M AU - Zhao, M TI - Summary on the Results of Two Computational Fluid Dynamic Benchmarks of Tube and Different Channel Geometries JF - JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE J2 - J NUCLEAR ENG RAD SCI VL - 4 PY - 2018 IS - 1 PG - 15 SN - 2332-8983 DO - 10.1115/1.4038162 UR - https://m2.mtmt.hu/api/publication/3332032 ID - 3332032 LA - English DB - MTMT ER - TY - CHAP AU - Kiss, Attila AU - Andrey, Churkin AU - Alexey, Krutikov AU - Luka, Golibrodo AU - Vasilii, Volkov AU - Darwan, S Pilkhwal AU - Abhijeet, M Vaidya AU - Walter, Ambrosini AU - Andrea, Pucciarelli AU - Krishna, Podila AU - Yanfei, Rao AU - Laurence, Leung AU - Chen, Yuzhou AU - Mark, Anderson AU - Meng, Zhao ED - anon, null TI - Two CFD benchmarks on SCWR related tube and different channel geometries T2 - Proceedings of the twenty-seventh Symposium of AER PB - MTA Energiatudományi Kutatóközpont CY - Budapest SN - 9789637351297 PY - 2017 SP - 993 EP - 1024 PG - 32 UR - https://m2.mtmt.hu/api/publication/3337182 ID - 3337182 LA - English DB - MTMT ER - TY - BOOK AU - Kiss, Attila AU - Balaskó, Márton AU - Horváth, László AU - Kis, Zoltán AU - Bartos, Júlia AU - Aszódi, Attila TI - Study on the thermal hydraulics of supercritical water under natural circulation flowing in a closed loop T3 - 8th International Symposium on Supercritical Water-cooled Reactors (ISSCWR-8) ET - 0 C1 - Chengdu PY - 2017 SP - 26 UR - https://m2.mtmt.hu/api/publication/3252895 ID - 3252895 LA - English DB - MTMT ER -