الفهرس 
CHAPTER ONE INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
One of the most pestering environmental problems that the refrigeration industry (ozone depletion). In principle, low-temperature driven adsorption based refrigeration systems have the advantage of using environmentally benign working fluids and these systems can exploit effectively waste heat sources otherwise should be purged to the ambient. Moreover, they are scalable to all capacities. The main challenges in adsorption refrigeration field are to adopt suitable adsorbent-refrigerant pairs and innovative system design. Consequently, the main objective of the present thesis is to investigate the quality of a new adsorbent pair namely AquaSorb 2000/HFC-404a as a working pair with an innovative double effect adsorbent bed.
The adsorption characteristics in terms of isotherms and kinetics have been investigated experimentally and theoretically. AquaSorb 2000 of type bituminous based carbon has been used as an adsorbent. Experimentally and theoretical investigations have been conducted within temperature range of 25–75°C. Experimental results have been fitted with Dubinin–Astakhov (D–A) and Tóth equations for the isotherms and linear driving force and Fickian diffusion models for the kinetics. The finding has been shown that maximum adsorption capacity is about 0.52 kg/kg. Activation energy and the pre-exponential coefficient were estimated to be 10488.49 J/mol and 1.11 respectively. Isosteric heat of adsorption as a function of relative adsorption capacity with non-ideal consideration has been also estimated using Clausius–Clapeyron equation and is found to vary from 145 to 330kJ/kg. Pressure–temperature–concentration diagram of the adsorption pair has been also evaluated.
A new design for an adsorption bed to optimize the performance of the adsorption cooling system has been built. The new design consider an idea of a double effect adsorber as it has three concentric tubes with inside and outside heating/cooling liquid. The adsorbent has been crammed in-between radial fins inside the in-between tube. The experimental results of test-rig had shown that the time cycle of double effect is about 900 sec and single effect is about 1460sec.
Based on the experimentally confirmed adsorption isotherms, heats of adsorption, adsorption kinetics and parameter of new design, a transient cycle simulation using pair of activated carbon/HFC404a is applied theoretically using a MATLAB code. The model has been
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investigated to work at different operating conditions. Double effect heating and cooling has been compared with a single effect heating and cooling in terms of coefficient of performance and specific cooling power. A benefit of higher than 200% improvement in specific cooling power (SCP) has been detected with no influence on coefficient of performance. The new design could achieve a SCP value of 40 W/kg and is able to be driven by a low grade heat source temperature lower than 100 ºC.
It has been validated experimental and theoretical results. The results have been acceptable to a large extent and thus can adopt the idea of improving the adsorbent bed in the cooling adsorption applications.