Combining the psychrometric chart of humid air with water adsorption isosters: Analysis of the Ventireg process

• Published in: Energy (Oxford) Vol. 239; p. 122278
• Main Authors: Aristov, Yu.I., Gordeeva, L.G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15.01.2022; Elsevier BV
• Subjects: Adsorbed water; Adsorbents; Adsorption; Adsorptivity; Air conditioning; Calcium chloride; Climatic zones; Desiccation; Dew point; Isosteric chart; Lithium chloride; Psychrometric chart; Silica; Silicon dioxide; Ultra-low temperature heat; VentireG process; Water adsorbent; Water harvesting; Ultra-low temperature heat; Psychrometric chart; Isosteric chart; Water adsorbent; VentireG process
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.122278

Adsorption processes are widely used to convert heat with low- or even ultralow-temperature (ULT) potential. For instance, the adsorptive VentireG process was proposed to regenerate ULT heat and moisture in ventilation systems in cold countries. In this paper, a new approach for a deeper analysis of this process is proposed. It is implemented by plotting water adsorption isosters for a specific adsorbent directly on the common psychrometric chart of humid air. Such a combined diagram would allow the states of air and the given adsorbent to be tracked simultaneously. The merged “psychrometric – isosteric” diagram is plotted for five adsorbents potentially promising for the VentireG process. Their possible application in typical climatic zones of cold countries is analyzed, and the conscious choice of proper adsorbents is made. Composites “salt (CaCl2, LiCl, LiBr) in silica pores” can exchange up to 0.4–0.5 g_H2O/g and ensure low dew point of the outlet air. In a broader sense, this new combined diagram can be used for analyzing any open adsorption cycles, e.g., for air conditioning, desiccation, water harvesting from the atmosphere, etc. •Common psychrometric chart of humid air is combined with water adsorption isosters.•It allows simultaneous tracking of the states of humid air and a given adsorbent.•The diagram is used to analyze the VentireG cycle for heat and moisture regeneration.•Composites “salt/silica” exchange 0.4–0.5 g_H2O/g and ensure low dew point of air.•The new diagram can be used for deeper analysis of any open adsorption cycles.