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Entropic analysis of adsorption open cycles for air conditioning. Part 2: interpretation of experimental data
Author(s) -
Kodama Akio,
Jin Weili,
Goto Motonobu,
Hirose Tsutomu,
Pons Michel
Publication year - 2000
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/(sici)1099-114x(20000310)24:3<263::aid-er579>3.0.co;2-m
Subject(s) - thermodynamics , entropy (arrow of time) , air conditioning , heat exchanger , desiccant , carnot cycle , evaporative cooler , mechanics , cooling capacity , coefficient of performance , mathematics , heat pump , physics , meteorology
The full second‐law analysis, developed in Part 1 (M. Pons and A. Kodama, Int. J. Energy Res. 2000; 24 : 251–262) is applied to experimental results. That approach takes into account the irreversibilities due to the open character of the cycle. Measurements are performed on a solid desiccant cooling unit operated in the ventilation mode. Experimental data permit us to establish the entropy balance of the unit. The results show that the sum of all the considered entropy productions completely explain the difference between the Carnot COP and the actual COP of the unit. The effects of three experimental parameters are investigated: the rotation speed of the dehumidifier (desiccant wheel), the air velocity and the regeneration temperature. Experimental results show that there exists an optimal rotation speed which results from a combination between the different entropy productions in the cycle. When the air velocity is increased, together with an accordingly optimized rotation speed, the cooling capacity increases while the COP decreases due to increases in the entropy productions in the dehumidifier and sensible heat exchanger. Moreover, it appears that the most significant entropy productions take place in the dehumidifier and heating system. In the investigated experimental unit, these two entropy productions have similar magnitudes. However, when the regeneration temperature is increased, the irreversibilities due to mass exchanges with outside air become comparable to these and surely should not be forgotten in a global optimization of the process. The present analysis is a solid basis for reducing the largest entropy productions thus optimizing the process. Copyright © 2000 John Wiley & Sons, Ltd.