| Autor: |
Seong Kuk Cho, Seong Jun Bae, Yongju Jeong, Jekyoung Lee, Jeong Ik Lee |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
Applied Sciences, Vol 9, Iss 19, p 4057 (2019) |
| Druh dokumentu: |
article |
| ISSN: |
2076-3417 |
| DOI: |
10.3390/app9194057 |
| Popis: |
To overcome the degradation of the cycle efficiency of a supercritical carbon dioxide (S-CO2) Brayton cycle with dry cooling, this study proposes an improved design of an S-CO2 centrifugal compressor. The conventional air centrifugal compressor can achieve higher efficiency as backsweep angle increases. However, the structural issue restricts the maximum allowable angle (−50~−56°). In this study, an S-CO2 centrifugal compressor performance was examined while changing the backward sweep angle at impeller exit to study if the previous optimum backsweep angle for an air centrifugal compressor is still valid when the fluid has changed. It is shown through an analysis that an S-CO2 centrifugal compressor can achieve the highest efficiency at −70° backsweep angle, which is greater than the typical design value. The S-CO2 centrifugal compressor is less restricted from a structural integrity issue because it has low relative Mach number regardless of the low sound speed near critical point (Tc = 304.11 K, Pc = 7377 kPa). It is also shown in the paper that the variation of compressibility factor does not impact on its total to total efficiency since its Mach number is still lower than unity. Finally, it is also shown that a backward sweep impeller can achieve higher pressure ratio and operate stably in wider range as the mass flow rate is decreased. As further works, the suggested concept will be validated by the structural analysis and the compressor performance test. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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