Mathematical Analysis of the Transient Dynamic of Surge-In Or/And Surge-Out of the Pressurizer of PWR

Nibal Fadel Farman, AL-Hialy (Univrsity of Baghdad & Engineering College, Iraq); Zeina Ali Abdul Redha (University of Baghdad & Engineering College, Iraq); Shaymaa ALasadi (Baghdad, Iraq)

Study and analysis of the dynamic transient behavior of the pressurizer of pressurized nuclear water reactor PWR. For a pressurized water reactor, the accurate prediction of system pressure is essential since system pressure is a key parameter in controlling system transient. For this purpose, the fundamental understanding and a reliable modeling of surge tank phenomena during transients are predicted .The dynamic pressure of the system and the transient behavior was investigated. Overpressure necessary to limit the bulk boiling is maintained by this pressurizer. The volume of the main coolant expands and contracts with average temperature variations causing in- surges and out- surges in the surge tank volume (have spray, relief system and electric heater) which is called "pressurizer". A pressurizer with a steam- light water interface is used to maintain the sensitive pressure-temperature balance in the primary system by using heaters to make more steam and increase pressure or spraying cool water to condense steam and reduce pressure. Increase and decrease coolant mass flow rate or specific volume leads to in-surge or out-surge transient, which changes pressurizer tank's pressure so tow region thermodynamic model release to analyzing the dynamic transient behavior in-surge and out-surge tanks. The basic balances equations of mass and energy conservation with boundary condition constant heat flux, the number of flashing drop and variation temperature to casing in or/ and out surges. Theoretical thermodynamic modeling which generates a comprehensive influence of each change was analyzed. It is shown that the agreement between the results is rather good for different sets of conditions.

Journal: International journal of simulation: systems, science & technology V18

Published: Dec 30, 2017

DOI: 10.5013/IJSSST.a.18.04.05