Numerical And Theoretical Research On PRHR-HX C-Type Tube AP1000 Flow And Heat Transfer Characteristics

Passive Residual Heat Removal Heat Exchanger(PRHR-HX)is one of the important safety components of PRHRs in AP1000 reactor which transport the heat from reactor core and dissipated in to In-containment Refilling Water Storage Tank(IRWST)through convection heat transfer natural circulation on bool boiling.Many research conducts on PRHR-HX and IRWST but still there many issue needs be investigated especially two-phase flow phenomena.In this work a single tube from PRHR-HX C-type tube was selected,the geometry of tube model was typical to prototype dimensions,the volume-power ratio was used to determine heated volume by single C-type tube,water level in scaled rectangular IRWST was taken same as prototype.ANSYS CFD-ICEM mesh,CFX solver was used for numerical analysis,transient single-phase flow,fluid to fluid interface model is used to describe the heat transfer coupling between primary and secondary sides.Single-phase flow primary side and secondary side were investigated.The temperature along the PRHR HX tube,temperature in tank,velocity distributions,and the heat transfer coefficient at different parts along PRHR HX were analyzed.Comparison between CFD result and experimental data of ROSA-V Large-Scale Test Facility(LSTF)has been made for model validation,theoretical results were made for Single phase flow heat transfer correlations along the PRHR-HX inner side;and Single-phase flow heat transfer correlations along the PRHR-HX secondary side specifically considered.Temperature at inner side of HX is decreased dramatically from inlet to outlet of tube,natural circulation and stratification are observed in the IRWST,heat transfer rate at vertical tube part of PRHR-HX is much greater than horizontal parts.Single tube full size with volume power ratio scaling for IRWST is capable to describe thermal-hydraulic behavior of tubes bundle.