A new perspective to the conventional solar pond technology to increase the thermal efficiency

Abstract

In this study, a new perspective was introduced to conventional solar pond technology to spread its commercial application. In order to make it more useful with preserving energy efficiency, the brine layers were replaced with the normal freshwater by using a separated transparent partition. Structurally modified three different solar ponds were proposed and numerical investigations were conducted by using discrete ordinate method (DOM). For this, four types of solar ponds were modeled, the first one is the conventional salt‐gradient solar pond and three others are modified versions which are named as “Pure Water Solar Pond.” For all models, a comprehensive finite element method was developed to investigate the daily performance of solar ponds by using commercial software COMSOL. Salt‐gradient solar pond consists of seven layers where one layer is the heat storage zone, five layers are nonconvective zone, and one is the upper convective zone. However, in the modified models, solar ponds consist of two glass layers and one to three pure water zones depending on the model types. The numerical method includes a novel approach to calculate all the zone where absorption, emission, scattering, transmission, convection, and radiation are taken into account. Numerical results for all models were compared with an experiment to correlate the numerical accuracy of the DOM with anisotropic scattering phase function. Results indicate there is a good correlation between these four model approach and the experiment.

The investigation of heat storage efficiency of salt gradient solar pond with and without phase changing materials

“…Zero represents the worst element quality and in general, elements with a quality below 0.1 are considered poor quality for many applications. [26][27][28] The COMSOL mesh module automatically presents a warning for elements with a quality below 0.01, as these are considered to be very low quality and should be avoided in most cases. 29 F I G U R E 2 A novel solar pond model.…”

“…For the quality measure, 1 is the best possible measure and indicates an optimal element in the chosen mesh configuration. Zero represents the worst element quality and in general, elements with a quality below 0.1 are considered poor quality for many applications 26–28 . The COMSOL mesh module automatically presents a warning for elements with a quality below 0.01, as these are considered to be very low quality and should be avoided in most cases 29…”

The investigation of using phase change material for solar pond insulation

“…A thin layer was defined over the PCM and the insulator materials by a thickness of 1 mm. In this study, direct solver PARDISO (a commercial version built-in COMSOL) with nested dissection multithreaded preordering algorithm was used due to its performance, robust, memory efficient and easy to use software for solving large sparse symmetric and unsymmetrical linear systems of equations on shared-memory and distributed-memory multiprocessors [10]. The method uses a large amount of RAM and processor as it makes a separate solution for each mesh point.…”

“…The temperature distribution was calculated by using finite element method. Sogukpinar [10] developed solar pond models to investigate the efficiency of the pond for different cases. The zones were composed of the freshwater to make it useful with preserving performance.…”