cfd simulation of hydrodynamics and scrubbing …
TRANSCRIPT
Kansas State University Libraries Kansas State University Libraries
New Prairie Press New Prairie Press
Symposium on Advanced Sensors and Modeling Techniques for Nuclear Reactor Safety
CFD SIMULATION OF HYDRODYNAMICS AND SCRUBBING CFD SIMULATION OF HYDRODYNAMICS AND SCRUBBING
BEHAVIOUR OF IODINE VAPORS IN A SELF-PRIMING VENTURI BEHAVIOUR OF IODINE VAPORS IN A SELF-PRIMING VENTURI
SCRUBBER SCRUBBER
Paridhi Goel Homi Bhabha National Institute, [email protected]
A. K. Nayak Bhaba Atomic Research Center, [email protected]
Follow this and additional works at: https://newprairiepress.org/asemot
Part of the Mechanical Engineering Commons, and the Nuclear Engineering Commons
Recommended Citation Recommended Citation Goel, Paridhi and Nayak, A. K. (2018). "CFD SIMULATION OF HYDRODYNAMICS AND SCRUBBING BEHAVIOUR OF IODINE VAPORS IN A SELF-PRIMING VENTURI SCRUBBER," Symposium on Advanced Sensors and Modeling Techniques for Nuclear Reactor Safety. https://newprairiepress.org/asemot/2018/fullprogram/1
This Poster is brought to you for free and open access by the Conferences at New Prairie Press. It has been accepted for inclusion in Symposium on Advanced Sensors and Modeling Techniques for Nuclear Reactor Safety by an authorized administrator of New Prairie Press. For more information, please contact [email protected].
CFD SIMULATION OF HYDRODYNAMICS AND SCRUBBING BEHAVIOUR OF IODINE VAPORS IN A SELF-
PRIMING VENTURI SCRUBBER
Paridhi Goela,b*and A.K Nayaka,b
aHomi Bhabha National Institute, Anushaktinagar, Mumbai – 400094, IndiabReactor Engineering Division, Bhabha Atomic Research Centre,Trombay, Mumbai–400085,India
IUSSTF Symposium on Advanced Sensors and Modeling Techniques for Nuclear Reactor Safety. 15th-19th December 2018, IIT Bombay.
Under extreme events in a nuclear reactor, the primary containment pressure may increase beyond the design pressure limit and
therefore must be depressurized.
CFVS employs a manifold of self-priming venturi scrubbers submerged in a pool of liquid.
The performance of the venturi scrubber significantly affects the overall performance of the system.
FUNCTIONS OF HARD VENT SYSTEM
Prevent over pressurization of the containment beyond design pressure.
Retain radionuclides (99.9% of Iodine and Cesium).
BACKGROUND
SYSTEM DESCRIPTION
Eulerian Gas Flow
k-ɛ RNG turbulence
Tracking of Droplets
Simplified Basset-Boussinesq-Oseen equation
Coupling between the phases via drag term
Drag coefficient is modeled as function of
Reynolds number and Weber number
Inertial effect of the entrained jet is accounted
Break up of droplets is simulated by KHRT
The removal of iodine from the venturi scrubber is
modelled assuming an instantaneous reaction
Steinberger and Treybal’s correlation of Sherwood
number is applied to calculate mass transfer
coefficient for each droplet
MODEL DEVELOPMENT
RESULTSRESULTS
EFFECT OF GAS FLOW RATE ON
SCRUBBING OF IODINE VAPORS
Developed a numerical model that validated experimental findings i.e. hydrodynamics and scrubbing behaviour observed in the venturi scrubber operated in self
priming mode through an Eulerian-Lagrangian framework.
The developed model gave insight to the droplets trajectory and the breakup behaviour as droplets were seen stripping from the edges while moving in the
domain.
The air phase accelerates in the converging section due to which the pressure decreases. At the nozzles location (0.2 m) there is a sharp pressure drop due to the
entrainment of liquid. The two phase pressure plot in the venturi scrubber showed no recovery in the diverging section.
The iodine retention efficiency in the venturi scrubber was found to increase along the length of venturi scrubber. The iodine retention in the venturi scrubber is
close to the experimentally measured value. This indicates that the participation of venturi scrubber in achieving the target for scrubbing in the considered
configuration of CFVS is significant.
CONCLUSIONS
Fig 1: Arrangement of Containment Filtered Venting System
considered in the present study
Fig 3: Droplet distribution calculated in
the venturi scrubber throat section
Table 1: Solver Settings and
Boundary ConditionsFig 2: Comparison of predicted and measured
pressure profile in the venturi scrubber
Fig 4: Scrubbing efficiency of
iodine vapors for 4100 lpm at 4m
submergence height
Fig 5. Contours of (a) gas only flow velocity
(b)Two phase gas velocity for 4100 lpm gas flow rate.
Fig 6. Percentage scrubbing of iodine vapors at
different gas flow rates