Evaporation heat transfer characteristics of R-245fa in a shell and plate heat exchanger for very-high-temperature heat pumps | |
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Year of publication | 2020 |
Title of paper | Evaporation heat transfer characteristics of R-245fa in a shell and plate heat exchanger for very-high-temperature heat pumps |
Author | Kang Sub Song, Sungho Yun, DongChan Lee, Kibong Kim, Yongchan Kim |
Publication in journal | International Journal of Heat and Mass Transfer |
Publication date | April 2020 |
Volume & other data | Volume 151, 119408 |
Abstract | A shell and plate heat exchanger (SPHE) has been introduced for use in very-high-temperature heat pumps (VHTHPs). However, studies on the evaporation heat transfer characteristics of refrigerants in SPHEs for use in VHTHPs are very limited. In this study, the evaporation heat transfer characteristics of R-245fa in the SPHE are measured and analyzed by varying the saturation temperature, mass flux, heat flux, mean vapor quality, and fluid direction. Experiments are conducted under high temperatures of 60−80 °C for VHTHP applications. The evaporation heat transfer coefficient increases as the mass flux and mean vapor quality increase, whereas it decreases as the heat flux increases. The two-phase frictional pressure drop increases as the mass flux and mean vapor quality increase. The heat transfer performance of the upward flow in the SPHE is better than that of the downward flow. In addition, empirical correlations of the Nusselt number and two-phase friction factor of R-245fa in the SPHE are derived. |
Keywords | Very-high-temperature heat pump, Shell and plate heat exchanger, R-245fa, Evaporation heat transfer, Two-phase pressure drop |
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HVAC
고려대학교 냉동공조 및 이상유동 연구실