Authors & Affiliations
Beznosov A.V., Chernysh A.S., Bokova T.A., Sergeyev S.I.
Nizhny Novgorod State Technical University (NNSTU), Nizhny Novgorod, Russia
Securing a safe and efficient transfer of reactor core afterheat in standby and emergency modes of reactor plants cooled with heavy liquid-metal coolants (HLMC) is necessary during developing a project and for operating such plants. The freezing (melting) temperature of lead (326ТАC) and leadbismuth (125ТАC) coolants (under these conditions) with heat removal by water, which is conventional for water and gas reactor plants, and with a pressure close to atmospheric (at a temperature up to 100ТАC) brings about freezing of HLMC in the heat-exchanger and termination of the coolant circulation through it. Removing heat from HLMC using an efficient, conventional coolant, i.e. water, within the entire range of its pressures up to critical one may result in lead freezing in the heat-exchanger. Removal of heat from HLMC using another conventional coolant, i.e. air, requires essentially larger heat exchange surfaces due to its low efficiency and, accordingly, an apparent increase in the volume of liquid metal in the heat-exchanger. The necessity of resolving the existing technical contradiction arising during designing and operating heat-exchangers with lead and lead-bismuth coolants using air and water cooling induces to searching for media, which would, on the one hand, remove heat from HLMC more efficiently than air and would, on the other hand, prevent HLMC from freezing in them and would ensure such heat removal at a pressure of the heat-eliminating medium close to atmospheric. In the course of the experiments, there were determined heat-exchange characteristics in the test section and the temperature of the air-steam mixture at varying flow rates of the lead coolant (up to 3.6 m3/h) and the air (up to 6 m3/h) with water condensate concentrations in the mixture ranging from 0 to 1.0% (volumetric) at modular designs of atomizers and varying orientations of TS in space.
coolant, heat-exchanger, heat-eliminating, atomizer, plumbum, circulation, water condensate, air, hundreds, pressure.
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