Performance comparison of various absorption heat transformers using nitrate-based absorbent systems
Environmental problems, including global warming effects due to carbon dioxide, have become serious because of high energy consumption, and, as a result, the development of energy-saving technologies is urgently needed. An important energy-saving technology is the recovery of exhaust heat. In various industrial processes, high-temperature exhaust heat has been recovered at an advanced level, but there is not yet efficient recovery of intermediate and low-temperature exhaust heat. Therefore, it is desirable to develop the technology to recover such low-quality exhaust heat in a manner capable of efficiently raising it to an elevated temperature for industrial re-use. The absorption heat transformer has recently attracted attention for use in the recovery of industrial exhaust heat. By using various working medium+absorbent systems containing nitrate-based adsorbents, a single-stage absorption heat transformer and an advanced absorption heat transformer were evaluated for theoretical performance characteristics. Six working medium+absorbent systems containing nitrates--H{sub 2}O+LiBr+LiNO{sub 3}, H{sub 2}O+LiCl+LiNO{sub 3}, H{sub 2}O+LiI+LiNO{sub 3}, H{sub 2}O+Ca(NO{sub 3}){sub 2}+LiNO{sub 3}, H{sub 2}O +Ca(NO{sub 3}){sub 2}+LiNO{sub 3}+KNO{sub 3}, and H{sub 2}O+LiNO{sub 3}+NaNO{sub 3}+KNO{sub 3}--were chosen for comparison with an H{sub 2}O+LiBr system. For the advanced absorption heat transformer, two types of high-temperature-lift cycles and three types of high-efficiency cycles were used for simulation. The systems H{sub 2}O+Ca(NO{sub 3}){sub 2}+LiNO{sub 3} and H{sub 2}O+Ca(NO{sub 3}){sub 2}+LiNO{sub 3}+KNO{sub 3}, which are less corrosive, can be used in the high-temperature range where the H{sub 2}O+LiBr system cannot.
- Research Organization:
- Kansai Univ., Osaka (JP)
- OSTI ID:
- 20002312
- Report Number(s):
- CONF-990102-; ISSN 0001-2505; TRN: IM200002%%312
- Resource Relation:
- Conference: ASHRAE Winter Meeting, Chicago, IL (US), 01/23/1999--01/27/1999; Other Information: PBD: 1999; Related Information: In: ASHRAE transactions 1999: Technical and symposium papers. Volume 105, Part 1, 1387 pages.
- Country of Publication:
- United States
- Language:
- English
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