TITLE:
Performance of an Activated Carbon-Ammonia Adsorption Refrigeration System
AUTHORS:
Tao Zeng, Hongyu Huang, Noriyuki Kobayashi, Jun Li
KEYWORDS:
Adsorption Refrigeration, Ammonia, Activated Carbon, Adsorption Isotherm, Adsorption Characteristics
JOURNAL NAME:
Natural Resources,
Vol.8 No.10,
October
31,
2017
ABSTRACT: An experimental study of the adsorption performances
of NH3 on several commercial activated carbons was described. Firstly,
the specific surface area, pore size distribution and morphological structure of
the activated carbons have been characterized by N2 adsorption, Scanning
Electron Microscope (SEM), and X-ray diffraction (XRD). The adsorption capacities
of four kinds of activated carbons were compared based on adsorption isotherms
at 30℃. Results show that a type of activated carbon MSC30 with high adsorption
capacity of NH3 is a promising adsorbent for NH3 because
of its large specific surface area and high pore volume. Secondly, the effect
of adsorption temperature on the adsorption capacity of NH3 on MSC30
was investigated. A modified Dubinin-Astakhov equation was employed to describe
the adsorption isotherms, with the reliability and accuracy evaluation. The
isosteric heat of adsorption of MSC30-NH3 as a function of the
amount adsorbed was calculated applying the Clausius-Clapeyron equation with
isotherms obtained at 20℃ and 30℃. Thirdly, a packed-bed type adsorber was
used to evaluate the influence of cycle time on the system cooling performance
(coefficient of performance, specific cooling performance, and volumetric
cooling performance) of the MSC30-NH3 pair at the evaporating
temperatures of 5℃, 10℃ and 15℃ with a fixed adsorption/condensing temperature and desorption
temperature of 30?C and 80℃,
respectively. Finally, a long term operation without degradation for MSC30-NH3 adsorption was experimentally demonstrated from the
80 consecutive adsorption-desorption cycles.