Testing of a Falling-Film Evaporator for Adsorption Chillers

Energies

Angelo Freni¹  Salvatore Vasta²  Tommaso Villa³  Tommaso Toppi³  Walter Mittelbach⁴ 

[1] CNR ICCOM—Consiglio Nazionale delle Ricerche Istituto di Chimica dei Composti Organometallici, 56124 Pisa, Italy;CNR—ITAE, Consiglio Nazionale delle Ricerche-Istituto di Tecnologie Avanzate per l’Energia ‘‘Nicola Giordano’’, 98126 Messina, Italy;Department of Energy, Politecnico di Milano, Via Lambruschini 4, 20156 Milan, Italy;Sorption Technologies GmbH, 79144 Freiburg, Germany;

关键词: adsorption chillers;    silica gel;    water evaporation;   

DOI  :  10.3390/en15051709

来源: DOAJ

【 摘 要 】

In this work, the performance of an innovative evaporator based on water falling film was investigated. The studied evaporator has been equipped with a recirculation system to maximise the wetted surface. Tests have been carried out in a lab-scale adsorption unit connected to a test bench recently realised at Politecnico di Milano labs for evaluating heat transfer performances under realistic operating conditions. Several ad/desorption cooling cycles were performed, setting different liquid refrigerant initial contents (0.9–1.5 kg), different chilled water inlet temperatures (7–20 °C) and flow rates (200–1000 L/h) and different adsorbent bed temperatures (25–30 °C). Evaporation performance has been determined in delivered cooling capacity. Moreover, the experimental data were used to calculate the overall evaporator heat transfer conductance (UA). Experiments showed how the heat duty peaks are mainly due to the thermal level of the chilled water that enters the evaporator, not the water content inside it because this value only affects the duration of the process. Instead, the UA value does not depend on the evaporator inlet chilled water temperature and initial mass content inside the evaporator. UA is 540–570 W/K for temperatures of chilled water entering the evaporator, equal to 10–20 °C, and mass of refrigerant of 0.9–1.5 kg.

【 授权许可】

Unknown