In steam generator using a condensation heat exchanger

In advanced nuclear power reactors, Pool heat exchangers are important feature of advancedpassive thermal–hydraulic safety systems. The performance of the heat exchanger tubedepends on the single phase (natural convection) heat transfer and two phase (Condensationand boiling) heat transfer phenomena taking place in the close vicinity of the walls of heatexchanger. For example, in the Advanced Power Reactor, the pool heat exchanger isassociated with a passive condensation cooling tank and passive auxiliary feed water systems(PAFS) in which the decay heat is removed from the reactor core by cooling down thesecondary system of the steam generator using a condensation heat exchanger installed in thePCCT, as reported by Yoon et al. (2014). Pool heat exchangers are also associated withpassive residual heat removal (PRHR) systems, isolation condenser systems (ICS), andpassive containment cooling systems (PCCS), as described by Cummins et al. (2003).The nuclear accidents like TMI (Three Mile Island), and Fukushima occurred due tosecondary cooling circuit failed which stop the residual decay heat removal from the core. Anuclear fraternity have challenge to design advanced nuclear reactors with enhanced safetyand reliability. To ensure this, many advanced nuclear reactors have adopted methodologiesof passive safety systems such as passive decay heat removal system (PDHRS) which areworking on natural forces such as gravity. During the seismic excitation, the performance ofpool type heat exchangers may effected due to fluctuations of coolant, which result in thechange in momentum, heat and mass transfer characteristics. Klaczak 1997 and Liu et al.2017 reported an experimental study on heat transfer of heat exchangers under mechanicalvibration. Both of them proposed a correlation to predict vibrational Nusselt number andclaimed that heat transfer in flowing fluid (laminar) enhanced by vibrational frequency andalso depend on the Reynolds number.