Numerical Simulation of a Shallow Solar Pond Operating Under the Batch Mode of Heat Extraction

2021 ◽  
pp. 147-152
Author(s):  
Abdelkrim Terfai ◽  
Younes Chiba ◽  
Mohamed Najib Bouaziz
Keyword(s):  
Numerical Simulation ◽  
Heat Extraction ◽  
Batch Mode ◽  
Solar Pond

Parametric study of a shallow solar-pond under the batch mode of heat extraction

2004 ◽  
Vol 78 (2) ◽  
pp. 159-177 ◽  
Author(s):  
S. Aboul-Enein ◽  
A.A. El-Sebaii ◽  
M.R.I. Ramadan ◽  
A.M. Khallaf
Keyword(s):  
Parametric Study ◽  
Heat Extraction ◽  
Batch Mode ◽  
Solar Pond

scholarly journals Experimental and CFD Studies of the Hydrodynamics in Wet Agglomeration Process

2018 ◽  
Vol 2 (3) ◽  
pp. 32 ◽  
Author(s):  
Benjamin Oyegbile ◽  
Guven Akdogan ◽  
Mohsen Karimi
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flow Analysis ◽  
Outer Region ◽  
Tangential Velocity ◽  
Numerical Code ◽  
Cfd Model ◽  
Rotating Disc ◽  
Batch Mode ◽  
Agglomeration Process

In this study, an experimentally validated computational model was developed to investigate the hydrodynamics in a rotor-stator vortex agglomeration reactor RVR having a rotating disc at the centre with two shrouded outer plates. A numerical simulation was performed using a simplified form of the reactor geometry to compute the 3-D flow field in batch mode operations. Thereafter, the model was validated using data from a 2-D Particle Image Velocimetry (PIV) flow analysis performed during the design of the reactor. Using different operating speeds, namely 70, 90, 110, and 130 rpm, the flow fields were computed numerically, followed by a comprehensive data analysis. The simulation results showed separated boundary layers on the rotating disc and the stator. The flow field within the reactor was characterized by a rotational plane circular forced vortex flow, in which the streamlines are concentric circles with a rotational vortex. Overall, the results of the numerical simulation demonstrated a fairly good agreement between the Computational Fluid Dynamics (CFD) model and the experimental data, as well as the available theoretical predictions. The swirl ratio β was found to be approximately 0.4044, 0.4038, 0.4044, and 0.4043 for the operating speeds of N = 70, 90, 110, and 130 rpm, respectively. In terms of the spatial distribution, the turbulence intensity and kinetic energy were concentrated on the outer region of the reactor, while the circumferential velocity showed a decreasing intensity towards the shroud. However, a comparison of the CFD and experimental predictions of the tangential velocity and the vorticity amplitude profiles showed that these parameters were under-predicted by the experimental analysis, which could be attributed to some of the experimental limitations rather than the robustness of the CFD model or numerical code.

Assessing the Maximum Stability of the Nonconvective Zone in a Salinity-Gradient Solar Pond

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
A. A. Abdullah ◽  
K. A. Lindsay
Keyword(s):  
Salinity Gradient ◽  
Fluid Velocity ◽  
Weather Conditions ◽  
Convective Zone ◽  
Heat Extraction ◽  
Solar Pond ◽  
Maximum Stability ◽  
Storage Zone ◽  
The Stability

The quality of the stability of the nonconvective zone of a salinity-gradient solar pond (SGSP) is investigated for an operating protocol in which the flushing procedure exactly compensates for evaporation losses from the solar pond and its associated evaporation pond. The mathematical model of the pond uses simplified, but accurate, constitutive expressions for the physical properties of aqueous sodium chloride. Also, realistic boundary conditions are used for the behaviors of the upper and lower convective zones (LCZs). The performance of a salinity-gradient solar pond is investigated in the context of the weather conditions at Makkah, Saudi Arabia, for several thickness of upper convective zone (UCZ) and operating temperature of the storage zone. Spectral collocation based on Chebyshev polynomials is used to assess the quality of the stability of the pond throughout the year in terms of the time scale for the restoration of disturbances in temperature, salinity, and fluid velocity underlying the critical eigenstate. The critical eigenvalue is found to be real and negative at all times of year indicating that the steady-state configuration of the pond is always stable, and suggesting that stationary instability would be the anticipated mechanism of instability. Annual profiles of surface temperature, salinity, and heat extraction are constructed for various combinations for the thickness of the upper convective zone and storage zone temperature.

Temperature evolution of an experimental salt-gradient solar pond

2010 ◽  
Vol 1 (4) ◽  
pp. 246-250 ◽  
Author(s):  
F. Suárez ◽  
A. E. Childress ◽  
S. W. Tyler
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Thermal Evolution ◽  
Low Cost ◽  
Heat Extraction ◽  
Low Grade ◽  
Distributed Temperature Sensing ◽  
Solar Pond ◽  
Thermal Desalination ◽  
Salt Gradient

A salt-gradient solar pond is a low-cost, large-scale solar collector with integrated storage that can be used as a source of energy in low-grade-heat thermal desalination systems. This work presents the thermal evolution of an experimental solar pond for both the maturation and heat extraction time periods. The temperature profile was measured every 1.1 cm using a vertical high-resolution distributed temperature sensing (DTS) system, with a temperature resolution of 0.04ºC. Temperatures of 34 and 45ºC were achieved in the bottom of the pond when the lights were on for 12 and 24 hours per day, respectively. Heat was extracted at a rate of 139 W from the solar pond, which corresponded to an efficiency of 29%. Stratification and mixing were clearly observed inside the solar pond using the vertical high-resolution DTS system.

Experiment and Numerical Simulation of a Seawater Solar Pond

2007 ◽  
pp. 1084-1088 ◽  
Author(s):  
Hua Wang ◽  
Wence Sun ◽  
Jianing Zou
Keyword(s):  
Numerical Simulation ◽  
Solar Pond

Concept of Triple Heat Exchanger-Assisted Solar Pond Through an Improved Analytical Model

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Sunirmit Verma ◽  
Ranjan Das
Keyword(s):  
Analytical Model ◽  
Power Output ◽  
Heat Exchangers ◽  
Thermal Power ◽  
Convective Zone ◽  
Heat Extraction ◽  
Extraction System ◽  
Seepage Water ◽  
Solar Pond ◽  
Bottom Zone

A new three-zone heat extraction system and its analytical model for maximizing the thermal power output of salt gradient solar ponds against a given volume is proposed. The present study considers internal heat exchangers installed within the non-convective zone (NCZ), lower-convective zone (LCZ), and the ground below the pond. The work is validated against a simplified version of the model (eliminating ground and bottom-zone heat extractions) available in the existing literature. Contrary to the conventional practice of optimizing only the middle-zone pond thickness, here, the newly proposed expression is used to find ideal values of both the middle- and bottom-zone thicknesses of the pond along with its cross-sectional area. The present work acknowledges that although the three-zone heat extraction system is the best, yet if a choice for two-zone heat extraction is to be made between the NCZ–LCZ and ground–LCZ, then the former is a better alternative. The power output is observed to increase asymptotically with mass flow rates of the three heat exchangers. However, their values must lie much below their theoretical asymptotic limits and their selection is regulated by constructional and operational constraints. These involve a minimum pond depth to offset surface evaporation, ground seepage water loss, and constraints preventing turbulent flow in heat exchangers to reduce friction loss and pumping power. This work recommends using three heat exchangers instead of either one or two and provides cardinal guidelines to extract heat in an ideal manner for a fixed solar pond volume.

Transient heat extraction modeling method for a rectangular type salt gradient solar pond

2017 ◽  
Vol 132 ◽  
pp. 316-326 ◽  
Author(s):  
Mohamad Aramesh ◽  
Fathollah Pourfayaz ◽  
Alibakhsh Kasaeian
Keyword(s):  
Modeling Method ◽  
Heat Extraction ◽  
Solar Pond ◽  
Salt Gradient
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