Experimental and three dimensional numerical analysis of cylindrical solar cooling adsorbent beds with circular heat exchange coils

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2016

Author

Gözükara, Arif Cem

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In this study three dimensional cylindrical adsorbent bed designs with circular heat transfer fluid paths had been investigated numerically and experimentally. Three dimensional high fidelity numerical coupled heat and mass transfer analyses of the proposed design alternatives are performed. Numerical analysis results are compared with the results of experiments using the temperature distributions within the adsorbent bed. In addition to geometric design features, effects of initial adsorption capacity, heat transfer fluid flow rate and inlet temperature are also investigated. In the numerical analyses both local thermal equilibrium and local thermal non-equilibrium approaches are used in comparison for modeling the heat and mass transfer within the bed. The results of experimental and numerical analyses are used for evaluating the heat recovery effectiveness of adsorbent beds. The maximum value of the axial temperature gradients within the bed is used as a measure of heat recovery effectiveness. Results had shown that reduced initial adsorption capacity, increased Heat Transfer Fluid (HTF) inlet temperature and flow rate increases the maximum value of the axial temperature gradients within the bed thus the heat recovery efficiency for same duration of operation. Additionally, effect of non-adsorbing (condensing) gas existence in the adsorption cooling system, had been discussed based on the two dimensional axisymmetric numerical analyses. Under the conditions analyzed, it had been shown that existence of non-condensing gas in the system had been significantly affects the temperature and adsorption capacity distribution within the bed during adsorption process. Whereas, its effect is less emphasized during desorption process.

Subject Keywords

Adsorption., Heat exchangers., Numerical analysis., Solar air conditioning.

URI

http://etd.lib.metu.edu.tr/upload/12619796/index.pdf
https://hdl.handle.net/11511/25482

Collections

Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

A. C. Gözükara, “Experimental and three dimensional numerical analysis of cylindrical solar cooling adsorbent beds with circular heat exchange coils,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.