Experimental and computational simulation of thermal stratification in large pools with immersed condenser. (25th February 2017)

• Record Type: Journal Article
• Authors: Kumar, Sunil; Vijayan, P.K.; Kannan, Umasankari; Sharma, Manish; Pilkhwal, D.S.
• Is Part Of: Applied thermal engineering. Volume 113(2017:Feb.)
• Page Start: 345
• Page End: 361
• Publication Date: 2017-02-25
• Subjects: Passive decay heat removal -- Gravity Driven Water Pool (GDWP) -- Thermal stratification -- Isolation Condenser (IC) performance -- RELAP5/MOD 3.2; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2016.10.175
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Thermal stratification in water pool has been studied. RELAP5/MOD 3.2 has been used to simulate observed thermal stratification. Characteristic curve for various stages of pool thermal stratification is presented. Thermal stratification is an issue during the initial few hours in pool boiling. Isolation condenser performance has been studied. Abstract: This paper deals with experimental and numerical investigations on thermal stratification phenomenon conducted in Integral Test Loop (ITL) scaled test facility for Advanced Heavy Water Reactor (AHWR). Experiments at decay power level were designed to simulate thermal hydraulic performance of Isolation Condenser (IC) system of AHWR at prototypical pressure (70 bar) and temperature (285 °C). The experiments were simulated using the Best Estimate (BE) thermal hydraulic system code RELAP5. Two different pool side nodalizations were tried for simulation of IC-pool. Nodalization, where the IC-pool was simulated with one lumped volume did not simulate the observed thermal stratification behavior appropriately. However, it simulated the Main Heat Transport System (MHTS) behavior well. To simulate pool side stratification a three volume pool nodalization was adopted, which simulated the observed thermal stratification behavior in the pool well apart from simulating MHTS system behavior. Study shows a characteristic thermal stratification behavior in pool, which prevails for the initial few hours of IC functioning. The characteristic curve showing various stages of observed pool thermal stratification development and decay during experiment has been presented in the paper. An interrelation between pressure and water level into the pool has been observed in studies.