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http://hdl.handle.net/1843/BUOS-9HZH35| Type: | Tese de Doutorado |
| Title: | Theoretical and experimental studies on boiling heat transfer for the zeotropic mixture R-407C |
| Authors: | Matheus Pereira Porto |
| First Advisor: | Luiz Machado |
| First Co-advisor: | Carlos F. M. Coimbra |
| First Referee: | Ricardo Nicolau Nassar Koury |
| Second Referee: | Antonio Augusto Torres Maia |
| Third Referee: | Carlos Umberto da Silva Lima |
| metadata.dc.contributor.referee4: | Antônio Carlos Lopes da Costa |
| Abstract: | This work concerns theorical and experimental methods for understanding the heat transfer mechanisms for a zeotropic fluid, namely R-407C. The refrigerant R-407C is a mixture of three refrigerants, R-134a, R-32, and R-125, which may replace R-22 in future refrigerant systems. Due to the degradation of heat transfer coefficients in mixtures such as R-407C, the classical relations may overestimate the experimental heat transfer rates. A correction based on nucleate boiling suppression factors that corrects a previously proposed relation is used to minimize the degradation error. The newly proposed relation was developed through a robust methodology based on genetic algorithm (GA) optimization for three additional refrigerants R-404a, R134a and R-22. A discussion about inventory is also presented, where a modified Otaki method is proposed for the more realistic scenario that corresponds of not knowing a priori the heat transfer coefficient. The inventory obtained by the modified Otaki method is higher than the one obtained by the traditional Otaki method. Both methods yield accurate results for R-407C. |
| Subject: | Engenharia mecânica |
| language: | Português |
| Publisher: | Universidade Federal de Minas Gerais |
| Publisher Initials: | UFMG |
| Rights: | Acesso Aberto |
| URI: | http://hdl.handle.net/1843/BUOS-9HZH35 |
| Issue Date: | 13-Sep-2013 |
| Appears in Collections: | Teses de Doutorado |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| tese_doutorado_mpp.pdf | 2.96 MB | Adobe PDF | View/Open |
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