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ISSN Online: 2688-7231

ISBN Online: 978-1-56700-524-0

Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
December, 17-20, 2021, IIT Madras, Chennai, India

Effect of thermocouple for sodium leak detection for an annular plenum in heat exchanger

Get access (open in a dialog) DOI: 10.1615/IHMTC-2021.3600
pages 2383-2388

要約

The nuclear heat generated in fast breeder reactor is removed by primary sodium and is transferred to secondary sodium using shell and tube heat exchangers. Sodium being an exothermically reactive element with air, additional guard shell is provided to avoid sodium leak from main shell and the interspace between main shell and guard shell is inerted with argon. The interspace is continuously monitored by using sodium leak detectors like mutual inductance probe, spark plug type leak detector etc. Pockets of about 6 mm inner diameter are provided in plenum for that purpose. In order to provide diversity in leak detection, an alternate method of leak detection is sorted. One of such method is to insert a thermocouple and monitor the temperature at pocket tip. Since, sodium is having very high thermal conductivity than inert gas, when sodium reaches the thermocouple, the measured temperature will be nearly equal to the flowing sodium temperature inside heat exchanger. Detailed studies are carried out by using CFD simulation considering actual geometry to estimate the temperature of thermocouple without any sodium leak and with sodium leak for the nominal sodium temperature of 525°C during reactor operation. Studies are also carried out for the shutdown condition during which the sodium temperature would be about 200 °C. Mesh independence study is carried out to check temperature for various mesh sizes. Different radiation heat transfer models were also compared to check for the conservative and better predictive heat transfer model for this study.