مدل محاسباتی رفتار گذرای تنظیم‌گر فشار در رآکتورهای آب سبک تحت فشار

The pressurizer component controls and maintains the pressure within the primary loop in Pressurized Water Reactor (PWR). It plays a vital role in the safe operation of PWRs. In this paper, the dynamic behavior of a pressurizer in transient condition is simulated. A numerical model based on three control volumes is considered to simulate the behavior of the pressurizer in transient condition. These three areas include the vapor region, saturated water in contact with vapor region and the region where the surged water is mixed with the water within the pressurizer. In the developed model, wall condensation, spray condensation, evaporation, bulk boiling and the energy absorption through the heater and heat transfer through the wall to ambient phenomena are taken into account. The mass, energy conservation with water-steam state equations are used to calculate the pressurizer pressure, water level and temperatures of each region. The presented model is developed as a software package so as the user can simulate all the available transient with a great ease. Specifically, by using the developed software, heater on/off, spray, in-surge, out-surge and opening of relief valve can be simulated by the user action or through predefined scenarios. The Massachusetts Institute of Technology (MIT) pressurizer test facility experimental data for in-surge, out-surge and out-surge after in-surge transients, are used to validate the developed model.