EDN: BTTYLY
Authors & Affiliations
Ryazapov R.R., Mamaev A.V., Sobornov A.E., Kuskov A.M., Kudashkin I.A.
Nizhny Novgorod State Technical University n.a. R.E. Alekseev, Nizhny Novgorod, Russia
Ryazapov R.R. – Junior Researcher Assistant. Contacts: 24, st. Minina, Nizhny Novgorod, Russia, 603950. Tel.: +7 (952) 459-95-53; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Mamaev A.V. – Junior Researcher Assistant.
Sobornov A.E. – Junior Researcher Assistant.
Kuskov A.M. – Undergraduate.
Kudashkin I.A. – Undergraduate.
Abstract
Non-isothermal mixing of coolant flows occurring in the water-cooled reactor plants equipment is accompanied by thermal pulsations. The high intensity of temperature pulsations and caused temperature stresses, can lead to NPU equipment units metal fatigue. The active supercomputers development in recent decades makes it possible to obtain statistical and spectral-correlation characteristics of pulsations using numerical methods. However, the results of three-dimensional calculations by computational fluid dynamics codes require experimental confirmation. The experimental study of the single-phase coolant thermal hydraulic characteristics of a non-isothermal mixing in a Y-junction with “counter injection” is relevant.
The study was carried out in a hydraulically closed circuit. The experimental model is a Y-junction with “counter injection” of cool coolant. It consist of main and peripheral angled pipes. Model material – transparent organic glass. During the experiment, «cold» (temperature 20 °С) and “hot” (temperature 80 °С) coolant flows were mixed in the model. The mass flux of the “hot” flow was at the level of 174.4 kg/(s·m2), of the “cold” varied in range from 198.5 to 330.9 kg/(s·m2) with a step of 33.1 kg /(s·m2). The mixing process visualization was carried out by contrast tracer injection, with similar density into the model. The tracer injection was carried out sequentially at four different points, it is followed by a video recording with a frequency of 30 Hz.
In the study, a video samples were obtained, as well as synchronous experimental temperature fields with them. The vortex formation in the mixing zone is traced. The scales of vortices, time-averaged temperature profiles, temperature intensity profiles are determined. A total analysis of the hydrodynamics and temperature state of the flow made it possible to determine the main reasons of temperature pulsations in the frontal region before the peripheral pipe.
Keywords
temperature pulsations, thermal pulsations, non-isothermal mixing, resource, durability, thermal hydraulic characteristics, tracer, coolant, power plant, tee node
Article Text (PDF, in Russian)
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UDC 621.039.534.25
Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2023, no. 2, 2:17
