Application of metal foams in air-cooled condensers for geothermal power plants: An optimization study

• Published in: International communications in heat and mass transfer 2011-08, Vol.38 (7), p.838-843
• Main Authors: Odabaee, Mostafa, Hooman, Kamel
• Format: Article
• Language: English
• Subjects: Air-cooled condensers; Applied sciences; Design engineering; Devices using thermal energy; Energy; Energy. Thermal use of fuels; Entropy; Exact sciences and technology; Finned-tube; Geothermal energy; Geothermal power plants; Heat exchangers; Heat exchangers (included heat transformers, condensers, cooling towers); Heat transfer; Metal foam heat exchangers; Metal foams; Natural energy; Optimization; Theoretical studies. Data and constants. Metering; Thermodynamics
• ISSN: 0735-1933; 1879-0178
• DOI: 10.1016/j.icheatmasstransfer.2011.03.028

Optimized design of metal foam heat exchangers, as replacements for finned-tubes in air-cooled condensers of a geothermal power plant, is presented here. Two different optimization techniques, based on first and second law (of thermodynamics) are reported. While the former aims at the highest heat transfer rate with as low pressure drop as possible, the latter minimizes the generated entropy in the thermodynamic system. Interestingly, the two methods lead to the same optimal design. The new design has been compared to the conventional air-cooled condenser designed and optimized by using the commercially available software ASPEN. It is shown that while the heat transfer rate increases significantly (by an order of magnitude) compared to the finned-tube for the same main flow obstruction height, the pressure drop increase is within an acceptable range. Further comparison between the two systems are carried out, making use of Mahjoob and Vafai's performance factor developed specifically for metal foam heat exchangers.