| This work is the continuation of a study completed within the framework of a European project (Joule 111, 2000), concerning the evaluation of the performances of a two-stage cascade type cycle, coupling a water/zeolite adsorption machine with a water/lithium-bromide absorption machine. The objective of this coupling is to increase the overall Coefficient of Performance (COP) of the installation. The present work examines the water/zeolite adsorption cycle. Experimental and numerical modelling results are reported.; The CNAM (Conservatoire National des Arts et Metiers de Paris) single effect installation has been used to carry out a two part experimental study. The first part characterizes the thermodynamic equilibrium between water and zeolite using a set of curves called adsorption isosteres. The second part evaluates the COP and Specific Cooling Power (SCP) of the machine.; The charting of the isosteres set revealed that the adsorbent contains about 50% less water than the estimated amount. This problem has a direct impact on the quantity of water cycled during the operation of the machine, thus leading to lower than expected performances. For evaporating (T b) and condensing (Tm) temperatures of 13°C and 45°C, respectively, and a regenerating temperature (Th) of 180°C, the COP and the SCP are 0.16 and 30 W/kg, respectively. When Th increases to 220°C, the COP and the SCP increase to 0.17 and 53.9 W/kg, respectively.; A numerical dynamic model of the machine has been proposed. This model includes a set of ordinary differential equations representing about thirty different mediums. This single effect model has been validated with success by comparing its predictions with the experimental results generated by the CNAM installation. (Abstract shortened by UMI.)... |
