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Title: Desiccant degradation in desiccant cooling systems: An experimental study

The authors conducted experiments to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. The source of contamination was cigarette smoke, which is considered one of the worst pollutants in building cooling applications. The authors exposed five different solid desiccants to ``ambient`` and ``contaminated`` humid air: silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. They obtained the moisture capacity of samples as a function of exposure time. Compared to virgin desiccant samples, the capacity loss caused by thermal cycling with humid ambient air was 10 percent to 30 percent for all desiccants. The capacity loss because of combined effect of thermal cycling with ``smoke-filled`` humid air was between 30 percent to 70 percent. The higher losses occurred after four months of experiment time, which is equivalent to four to eight years of field operation. Using a system model and smoke degradation data on silica gel, the authors predicted that, for low-temperature regeneration, the loss in performance of a ventilation-cycle desiccant cooling system would be between 10 percent to 35 percent, in about eight years, with higher value under worst conditions.
Authors:
 [1]
  1. National Renewable Energy Lab., Golden, CO (United States)
Publication Date:
OSTI Identifier:
143935
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solar Energy Engineering; Journal Volume: 115; Journal Issue: 4; Other Information: PBD: Nov 1993
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; DESICCANTS; THERMAL CYCLING; SURFACE CONTAMINATION; COOLING SYSTEMS; PERFORMANCE; TOBACCO SMOKES; RESIDENTIAL BUILDINGS; COMMERCIAL BUILDINGS