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Indexed by:期刊论文

Date of Publication:2015-01-01

Journal:HEAT TRANSFER RESEARCH

Included Journals:EI、SCIE、Scopus

Volume:46

Issue:4

Page Number:399-415

ISSN No.:1064-2285

Key Words:high-temperature conditions; low-temperature conditions; absorption heat transformer; exergy; energy level difference

Abstract:In this paper, the thermodynamic analysis and comparison of the performance of a single-effect water lithium bromide absorption heat transformer in high- and low-temperature conditions is presented. The energy, exergy, and the energy level difference methods have been used to analyze the performance of the system for both conditions in detail. The analysis involves the effect of the gross temperature lift (GTL) on the coefficient of performance (COP), exergetic efficiency, exergy destruction, and energy level difference for all the components in high- and low-temperature conditions. The results indicate that the exergetic efficiency for the high-temperature conditions varies between 0.8 and 0.9 which is higher and more stable than that for the low-temperature conditions varying between 0.4 and 0.7. The absorber and the solution heat exchanger are the components wherein the irreversibilities for the high-temperature conditions are higher than those for the low-temperature conditions at some GTL. This means that these components should be carefully designed and optimized for the high-temperature conditions. Furthermore, the energy level difference analysis methodology used here is found to be a powerful and systematic tool in disclosing the mechanism of exergy destruction in energy conversion processes.