Thermodynamic optimization of irreversible power cycles with constant external reservoir temperatures

Journal Article · Tue Oct 01 04:00:00 UTC 1991 · Journal of Engineering for Gas Turbines and Power; (United States)

DOI:https://doi.org/10.1115/1.2906269· OSTI ID:5126573

Swanson, L W ^[1]

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1. Dept. of Engineering, Univ. of Denver, Denver, CO (US)

In this paper an extended version of the Bejan model of irreversible power plants is proposed using a log-mean temperature difference (LMTD) representation for both the high and low-temperature heat exchangers. The analysis focuses on minimizing the irreversibilities associated with the hot and cold heat exchangers. The results indicate that the maximum power output, external conductance allocation ratio, and second law efficiency are functions of the number total heat exchanger transfer units (N), and are asymptotic to Bejan's original results as N {yields} O. This asymptote represents a global power output maximum and occurs for either extremely high cycle flow rates or cycle phase change processes in both heat exchangers. The LMTD representation also shows that under optimal conditions, more conductance should be allocated to the low-temperature heat exchanger as N increases.

• OSTI ID: 5126573
• Journal Information: Journal of Engineering for Gas Turbines and Power; (United States), Journal Name: Journal of Engineering for Gas Turbines and Power; (United States) Vol. 113:4; ISSN JETPE; ISSN 0742-4795
• Country of Publication: United States
• Language: English

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