Energy and Exergy Analysis of an Absorption and Mechanical System for a Dehumidification Unit in a Gelatin Factory.

Autor: Lima LS; School of Mechanical Engineering, University of Campinas, Mendeleyev St., 200-Cidade Universitária, Campinas 13083-970, Brazil., Keutenedjian Mady CE; Department of Mechanical Engineering, Centro Universitário da FEI, São Bernardo do Campo 09850-901, Brazil.
Jazyk: angličtina
Zdroj: Entropy (Basel, Switzerland) [Entropy (Basel)] 2021 Mar 31; Vol. 23 (4). Date of Electronic Publication: 2021 Mar 31.
DOI: 10.3390/e23040415
Abstrakt: In this paper, an energy and exergy analysis is applied to the air dehumidification unit of a liquid desiccant system in an industrial gelatin conveyor dryer. The working fluid is a binary solution of lithium chloride (LiCl) in water. Dry air is used in order to decrease the amount of liquid in the gelatin. Therefore, the environmental air must have its absolute humidity reduced from about 12 g/kg to the project target, which is 5 g/kg. The process is a cycle using an absorption desiccant unit (LiCl in water), where the weak solution absorbs water vapor from the air. In the regenerator, condensation of the solution (desorption) from the moist air occurs. As a result, the steam consumption of the desorber and electrical power used for the vapor compression chiller (with ammonia, NH3, as working fluid) are the primary sources of cost for the factory. To improve the plant's energy and exergy behaviors, the process is evaluated using a mathematical model of the system processes. In addition, we evaluate the substitution of the vapor compression chiller by an absorption unit (lithium bromide (LiBr) in water). The performance indicators of the compression vapor systems showed the best results. Even when using the condenser's energy to pre-heat the solution, the installed system proved to be more effective.
Databáze: MEDLINE
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