Stability Analysis of Salt-gradient Solar Pond under External Heat Addition with Different Salts

Abstract External heat supply to solar ponds from various types of solar collectors is a feasible alternative that significantly enhances its performance. In this work, various design parameters in a hybrid solar pond with external heat addition from Evacuated Tube Solar Collector (ETSC) are evaluated using an inverse approach. A forward model based on heat balance equations is solved for various zones of the solar pond to predict temperatures attained by its storage zone under a given climatic condition. Bryant and Colbeck’s relation is used to account for the diminution of the solar radiation as it travels from upper layers of the solar pond to its bottom layers. The relevant differential equations are solved using a Runge-Kutta fourth order scheme. The component of heat addition from ETSC is added to the forward model in the storage zone’s equation. Heat added from ETSC is considered proportional to the fraction of the aperture area to the pond’s base area, the thermal efficiency of ETSC and global solar radiation incident on ETSC. Both the forward model of the solar pond and combined solar pond and ETSC model were validated with previous experimental and numerical studies available in the literature for El Paso, USA, and Melbourne, Australia. An inverse model based on genetic algorithm is proposed for evaluating the set of geometrical parameters of ETSC and solar pond in order to derive a required performance from the combined solar pond-ETSC system.

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Transient modeling of a salt gradient solar pond using a hybrid Finite-Volume and Cascaded Lattice-Boltzmann method: Thermal characteristics and stability analysis

Energy Conversion and Management ◽

10.1016/j.enconman.2017.12.085 ◽

2018 ◽

Vol 158 ◽

pp. 416-429 ◽

Cited By ~ 6

Author(s):

A. El Mansouri ◽

M. Hasnaoui ◽

A. Amahmid ◽

R. Bennacer

Keyword(s):

Stability Analysis ◽

Lattice Boltzmann Method ◽

Finite Volume ◽

Lattice Boltzmann ◽

Thermal Characteristics ◽

Solar Pond ◽

Transient Modeling ◽

Salt Gradient ◽

Boltzmann Method

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Investigation of Thermal Performance of a Solar Pond With External Heat Addition

Journal of Solar Energy Engineering ◽

10.1115/1.4038788 ◽

2018 ◽

Vol 140 (2) ◽

Cited By ~ 8

Author(s):

Sayantan Ganguly ◽

Abhijit Date ◽

Aliakbar Akbarzadeh

Keyword(s):

Thermal Performance ◽

Heat Removal ◽

External Source ◽

External Heat ◽

Heat Extraction ◽

Heat Addition ◽

Solar Pond ◽

Heat Demand ◽

External Sources ◽

Evacuated Tube

This study addresses the method of adding heat to a salt gradient solar pond (SGSP) from external sources and investigates the thermal performance of the pond. In this case, the external heat source is solar heat collected by evacuated tube solar collectors (ETSC), and collected heat is transferred to the lower-convective zone (LCZ) of the SGSP by circulating fluid from the LCZ. Results show that heat addition from the external source enhances the thermal performance of the SGSP in terms of heat recovery and thermal efficiency but with certain constraints. The heat addition efficiency reduces with increase in aperture area of the ETSC. Also with increasing heat addition, the heat removal from the SGSP has to be increased; otherwise, the SGSP efficiency reduces rapidly. Heat removal from SGSP has to be performed keeping in mind the heat demand and the quality of heat. The latter reduces with an increase of heat extraction beyond a certain limit. Hence, optimizing the range of parameters in case of adding heat from external sources is very important for the best performance of a SGSP.

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Numerical study of Soret and Dufour coefficients on heat and mass transfer in a salt gradient solar pond

10.1063/5.0049389 ◽

2021 ◽

Author(s):

Yassmine Rghif ◽

Belkacem Zeghmati ◽

Fatima Bahraoui

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Numerical Study ◽

Solar Pond ◽

Salt Gradient

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Assessment of a vertical high-resolution distributed-temperature-sensing system in a shallow thermohaline environment

Hydrology and Earth System Sciences ◽

10.5194/hess-15-1081-2011 ◽

2011 ◽

Vol 15 (3) ◽

pp. 1081-1093 ◽

Cited By ~ 45

Author(s):

F. Suárez ◽

J. E. Aravena ◽

M. B. Hausner ◽

A. E. Childress ◽

S. W. Tyler

Keyword(s):

High Resolution ◽

Temperature Sensing ◽

Distributed Temperature Sensing ◽

Temperature Resolution ◽

Spatial And Temporal Scales ◽

Solar Pond ◽

Salt Gradient ◽

Time Averages ◽

Corrosive Environments ◽

And Storage

Abstract. In shallow thermohaline-driven lakes it is important to measure temperature on fine spatial and temporal scales to detect stratification or different hydrodynamic regimes. Raman spectra distributed temperature sensing (DTS) is an approach available to provide high spatial and temporal temperature resolution. A vertical high-resolution DTS system was constructed to overcome the problems of typical methods used in the past, i.e., without disturbing the water column, and with resistance to corrosive environments. This paper describes a method to quantitatively assess accuracy, precision and other limitations of DTS systems to fully utilize the capacity of this technology, with a focus on vertical high-resolution to measure temperatures in shallow thermohaline environments. It also presents a new method to manually calibrate temperatures along the optical fiber achieving significant improved resolution. The vertical high-resolution DTS system is used to monitor the thermal behavior of a salt-gradient solar pond, which is an engineered shallow thermohaline system that allows collection and storage of solar energy for a long period of time. The vertical high-resolution DTS system monitors the temperature profile each 1.1 cm vertically and in time averages as small as 10 s. Temperature resolution as low as 0.035 °C is obtained when the data are collected at 5-min intervals.

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