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고지운(Ji-Woon Ko),전동순(Dong-Soon Jeon) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
In this paper, the evaluation of thermal performance on condensation tubes for centrifugal chiller was carried out. The objective is to obtain the comparison data for overall heat transfer coefficient of condensation tubes. By the FPI(Fin Per Inch) and knurling, the 12 different condensation tubes were determined. And the refrigerant used in the experiment are HFO R1233zd(E). The experiment was carried out in a saturated temperature 38℃, inlet temperature and flow velocity of coolant have been fixed at 32℃ and 2㎧ respectively. As a result, the thermal performance of condensation tube with FPI and knurling of 45 and 84 respectively was the highest. Also, it was found that outside geometries of tubes have strong effects on the overall heat transfer coefficient.
쉘앤튜브 열교환기에서 R1234ze(E) 및 R1233zd(E)의 막응축 열전달 특성에 관한 연구
고지운(Ji-Woon Ko),장수영(Soo-Young Jang),전동순(Dong-Soon Jeon) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11
In this study, experimental investigations on the film condensation heat transfer characteristics of shell and tube heat exchanger were carried out. Low GWP refrigerants used in this study were R1234ze(E) and R1233zd(E). And we compared those refrigerants with R134a. Experimental conditions were selected temperature of saturated vapour, inlet temperature and volumetric flow rate of coolant. The velocity of coolant ranges about 1 ~ 2.5 m/s and inlet temperature of coolant and temperature of saturated vapour have been fixed at 32.0℃ and 38.0℃ respectively. It was found that ranges of the Overall heat transfer coefficients of R134a, R1234ze(E) and R1233zd(E) were 3.79 ~ 7.17, 3.60 ~ 6.59 and 3.24 ~ 5.67 kW/m²K respectively. And the heat transfer coefficient of tube outside was proved the largest value at R134a.