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Experimental and simulation approach of the loop geometry effect on the natural circulation system of the advanced nuclear reactor
Hariyanto D.a, Permana S.a, Suprijadia
a Nuclear Physics and Biophysics Research Division, Physics Department, Nuclear Science and Engineering Department, Institut Teknologi Bandung, Bandung, Indonesia
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]© 2020 John Wiley & Sons LtdLately, natural circulation has become an exciting topic because it has been proposed and applied in some advanced nuclear reactors as a passive safety system. The aim of the present study is to examine the effect of the loop geometry on the natural circulation based cooling system of a given power source. The experimental approach was achieved by the construction of two natural circulation loops with vertical heater and vertical cooler. Both circulation loops were built with a same vertical length of 100 cm and different horizontal lengths, each of 50 and 100 cm, respectively. The heater was realized with a stainless pipe wrapped by a Nichrome wire, whereas the cooling system was designed and built as a pipe in 30 cm long square tube. Thus, the cooling water will circulate around the pipe loop inside the rectangular cooling chamber. The temperature data acquisition was achieved via an Arduino-based system, controlling four K-type thermocouple sensors. The numerical simulation part in the present work, was carried out by the COMSOL Multiphysics software, using the dedicated heat transfer and fluid dynamic module, namely the computational fluid dynamic module. The experimental data were considered to parameterize the COMSOL input model. The experimental results showed a clear difference between two passive cooling loops according to the horizontal length. The doublings of the horizontal and vertical lengths of the loop have a direct effect on the fluid flow rate.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Advanced nuclear reactors,Comsol multiphysics,Experimental approaches,K-type thermocouples,Natural circulation,Natural circulation loop,Natural circulation system,Passive safety systems[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text]buoyancy,flow rate,loop geometry,natural circulation system,safety,thermal behavior[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text][{‘$’: ‘Decentralization Research Program of the Ministry of Research, Technology and Higher Education, the Republic of Indonesia; Lembaga Pengelola Dana Pendidikan (LPDP) ‐ Ministry of Finance, the Republic of Indonesia Funding information’}, {‘$’: ‘The author would like to acknowledge to Decentralization Research Program of the Ministry of Research, Technology and Higher Education for the support and to Lembaga Pengelola Dana Pendidikan (LPDP) – Ministry of Finance, the Republic of Indonesia for supporting the first author by providing educational scholarships. NOMENCLATURE t time (s) ? fluid density (kg/m3) ?0 fluid reference density (kg/m3) u flow velocity (m/s) uss steady-state fluid flow rate (m/s) p pressure (Pa) ? dynamic viscosity (Pa s) ?w dynamic viscosity at wall temperature (Pa s) T0 initial temperature (K) T temperature (K) g acceleration of gravity (m/s2) ? coefficient of thermal expansion (1/K) cp heat capacity at constant pressure (J/kg K) k thermal conductivity (W/m K) q0 heat flux (W/m2) Q total heat source (W) D inner diameter of the pipe (m) L total loop length (m) T transpose I identity tensor Ress steady-state Reynolds number Pr Prandtl number Nuss steady-state Nusselt number Gz Graetz number ? viscosity correction’}, {‘$’: ‘The author would like to acknowledge to Decentralization Research Program of the Ministry of Research, Technology and Higher Education for the support and to Lembaga Pengelola Dana Pendidikan (LPDP) ‐ Ministry of Finance, the Republic of Indonesia for supporting the first author by providing educational scholarships. NOMENCLATURE time (s) fluid density (kg/m ) fluid reference density (kg/m ) flow velocity (m/s) u steady‐state fluid flow rate (m/s) pressure (Pa) dynamic viscosity (Pa s) dynamic viscosity at wall temperature (Pa s) initial temperature (K) temperature (K) g acceleration of gravity (m/s coefficient of thermal expansion (1/K) heat capacity at constant pressure (J/kg K) thermal conductivity (W/m K) heat flux (W/m ) total heat source (W) inner diameter of the pipe (m) total loop length (m) T transpose identity tensor Re steady‐state Reynolds number Pr Prandtl number Nu steady‐state Nusselt number Gz Graetz number viscosity correction t ρ 3 ρ 0 3 u ss p μ μ w T 0 T 2 ) β c p k q 0 2 Q D L I ss ss ϕ’}][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.1002/er.5903[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]