Document Type : Original Article
Authors
1 M. Sc. Student Mechanics of Biosystems Engineering, Tarbiat Modares University (TMU), Tehran, Iran.
2 Associate Professor, Mechanics of Biosystems Engineering, Tarbiat Modares University (TMU), Tehran, Iran.
3 Professor, Mechanics of Biosystems Engineering, Tarbiat Modares University (TMU), Tehran, Iran.
Abstract
Concentrators have many functions, one of which is their use in the evaporation of liquids. Since a high level of heat is present in concentrator absorbers, it is possible to develop a heat exchanger system that enables the vaporization of salt water. One of the main components of these systems is the heat absorber, which is located at the focal point. In this study, an attempt was made to investigate two geometries of annular and hollow absorbers using the computational fluid dynamics (CFD) method. For this purpose, the working fluid was defined based on the properties of seawater in the Fluent Ansys software, and the creation of the geometry and thermal analysis was considered based on the initial and boundary conditions of the system. The results of the validation of the grid quality showed that the use of a tetrahedral grid with square grid order is suitable for the cylindrical geometry. Due to the dimensional symmetry of the geometry of the ring converter, the use of the simplest grid method leads to a high accuracy of the solver. The thermal analysis of the absorber has shown that with the cavity geometry, the heat distribution at the bottom of the geometry is greater than at the top. The results of the Nusselt number change analysis showed the concentration of thermal stress in the area of the liquid outlet. This stress concentration leads to a shift of the evaporation process from the inside of the chamber to the transfer tubes.
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