• Title/Summary/Keyword: Heat Removal

Search Result 625, Processing Time 0.028 seconds

OPTIMAL DESIGN FOR COOLING SYSTEM OF DRIVING UNITS FOR HYBRID VEHICLES (하이브리드 자동차 구동시스템용 냉각 유로 최적화에 관한 연구)

  • Lee, K.H.;Kim, Jae-Won;Ahn, E.Y.
    • Journal of computational fluids engineering
    • /
    • v.14 no.1
    • /
    • pp.62-69
    • /
    • 2009

  • The cooling system for electric devices of hybrid vehicles is examined. The present system is composed of coolant paths, inlet diffuser and heat sinks whose shapes are diamond and circular. In this work, inlet duct and fin arrays are combined in proposed models and examined by numerical calculations. Nusselt number and Reynolds number are considered for heat transfer performance. Main focus lies on the looking for optimal model for the cooling system adopted to compact driving module of a hybrid vehicle. The optimal model shows uniform flow patterns in the inlet diffuser and secondary flows after the fins attached to heat source. It is found that the vortical flows around the heat sinks are effective for heat removal mechanism.

  • PDF KSCI

BACKUP AND ULTIMATE HEAT SINKS IN CANDU REACTORS FOR PROLONGED SBO ACCIDENTS

  • Nitheanandan, T.;Brown, M.J.
    • Nuclear Engineering and Technology
    • /
    • v.45 no.5
    • /
    • pp.589-596
    • /
    • 2013

  • In a pressurized heavy water reactor, following loss of the primary coolant, severe core damage would begin with the depletion of the liquid moderator, exposing the top row of internally-voided fuel channels to steam cooling conditions on the inside and outside. The uncovered fuel channels would heat up, deform and disassemble into core debris. Large inventories of water passively reduce the rate of progression of the accident, prolonging the time for complete loss of engineered heat sinks. The efficacy of available backup and ultimate heat sinks, available in a CANDU 6 reactor, in mitigating the consequences of a prolonged station blackout scenario was analysed using the MAAP4-CANDU code. The analysis indicated that the steam generator secondary side water inventory is the most effective heat sink during the accident. Additional heat sinks such as the primary coolant, moderator, calandria vault water and end shield water are also able to remove decay heat; however, a gradually increasing mismatch between heat generation and heat removal occurs over the course of the postulated event. This mismatch is equivalent to an additional water inventory estimated to be 350,000 kg at the time of calandria vessel failure. In the Enhanced CANDU 6 reactor ~2,040,000 kg of water in the reserve water tank is available for prolonged emergencies requiring heat sinks.

  • https://doi.org/10.5516/NET.03.2013.711 인용 PDF KSCI KPUBS