Experimental and numerical investigation on suppression of thermal stratification in a water-pool: PIV measurements and CFD simulations

• Published in: Applied thermal engineering Vol. 138; pp. 686 - 704
• Main Authors: Kumar, Sunil, Grover, R.B., Yadav, H., Vijayan, P.K., Kannan, U., Agrawal, A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 25.06.2018; Elsevier BV
• Subjects: Compartments; Computational fluid dynamics; Computational physics; Computer simulation; Fluid dynamics; Gravity Driven Water Pool (GDWP); Heat exchangers; Heat transfer; Numerical analysis; OpenFOAM; Particle Image Velocimetry; Passive Decay Heat Removal System (PDHRS); Shrouds; Thermal stratification; Velocity measurement; Water circulation; Water temperature; OpenFOAM; Passive Decay Heat Removal System (PDHRS); Thermal stratification; Shrouds; Gravity Driven Water Pool (GDWP); Particle Image Velocimetry
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2018.04.070

•Pool with immersed heat exchanger leads to thermal stratification.•Particle Image Velocimetry measurements used to study flow patterns.•Experiments simulated using CFD software OpenFOAM.•Shrouds arranged around heaters promote pool water circulation.•Shrouds suppress thermal stratification in a pool. This paper deals with experimental and numerical investigation on thermal stratification phenomenon conducted in a scaled transparent pool using Particle Image Velocimetry (PIV) technique and Computational Fluid Dynamics (CFD) simulations respectively. Experiments were designed to simulate thermal stratification in a pool with an immersed heat exchanger. In general, pools with an immersed heat exchanger tend to get thermally stratified; preventing mixing and participation of the whole pool during the heat removal process. The study presented in the paper, focuses on quantification of thermal stratification in the pool without shrouds and examines the effect of shrouds on suppression of thermal stratification. The installation of three shrouds divides the pool in four compartments and ensures participation of the whole pool inventory in the heat removal process. In all the four compartments, pool water circulation was observed since the beginning of the heat transfer from the heater. In a three-shroud configuration, because of mixing, rate of rise of temperature of water near the top decreases.