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Pham Quang Vu,Kwang-Il Choi,Jong-Taek Oh 대한설비공학회 2018 대한설비공학회 학술발표대회논문집 Vol.2018 No.11
The use of HCFCs refrigerants is gradually being replaced by HFCs and hydrocarbons refrigerants that have zero ODP (Ozone Depletion Potential). R-290 (propane) is a hydrocarbon refrigerant with C3H8 molecular structure. In this research, the flow condensation heat transfer occurs inside an aluminum multiport mini-channel tube with 0.83㎜ of hydraulic diameter. In order to determine the value of heat transfer coefficient, the experiment was carried out for mass fluxes ranging from 50㎏/㎡s to 500㎏/㎡s, heat fluxes ranging from 3㎾/㎡ to 12㎾/㎡, and saturation temperatures of 48℃. the condensation heat transfer coefficient of propane is influenced by vapor quality, mass flux, and heat flux. A new correlation for condensation heat transfer coefficient was developed with present experimental data.
Flow condensation heat transfer of R410A in the multiport minichannel tube
Pham Quang Vu,Kwang-Il Choi(최광일),Jong-Taek Oh(오종택),Honggi Cho(조홍기),Taehun Kim(김태헌) 대한설비공학회 2015 대한설비공학회 학술발표대회논문집 Vol.2015 No.11
The flow condensation heat transfer characteristics of R410A in the multiport minichannels tube are presented. The multiport minichannels test tubes have 18 channels with 0.83mm hydraulic diameter was designed as a counter flow tube in tube heat exchanger. The experiment was performed with mass fluxes of refrigerant between 50 and 500 kg/(m2s), with 3 to 15 kW/(m2) heat flux, and saturation temperature of 48C. The effect of heat flux, mass flux and vapor qualities on the heat transfer coefficient and frictional pressure gradient are discussed.
Vu, Pham-Quang,Choi, Kwang-Il,Oh, Jong-Taek,Cho, Honggi World Scientific Publishing Co. Pte. Ltd. 2017 International Journal of Air-Conditioning and Refr Vol.25 No.2
<P>The condensation heat transfer coefficients and pressure drops of R410A and R22 flowing inside a horizontal aluminum multiport mini-channel tube having 18 channels are investigated. Experimental data are presented for the range of vapor quality from 0.1 to 0.9, mass flux from 50 to 500<TEX>$ \,$</TEX>kg/m<SUP>2</SUP>s, heat flux from 3 to 15<TEX>$ \,$</TEX>kW/m<SUP>2</SUP> and the saturation temperature at 48<TEX>$ ^{\circ }$</TEX>C. The pressure drop across the test section was directly measured by a differential pressure transducer. At a small scale, the noncircular cross-sections can enhance the effect of the surface tension. The average heat transfer coefficient increased with the increase of vapor quality, mass flux and heat flux. Under the same test conditions, the heat transfer coefficients of R22 are higher than those for R410A, the pressure drops for R410A are 7-19% lower than those of R22. The lower pressure drop of R410A has an important advantage as an alternative working fluid for R22 in air-conditioning and heat pump systems.</P>
Experimental investigation of flow condensation in the micro-fin tube
Pham Quang Vu,Kwang-Il Choi,Jong-Taek Oh,Honggi Cho 대한설비공학회 2018 대한설비공학회 학술발표대회논문집 Vol.2018 No.6
This study experimentally investigated the flow condensation heat transfer characteristics of R410A, R22, R32 and R290 (propane) inside a 7mm OD micro-fin copper tube. The flow condensation heat transfer was measured at mass fluxes of 50 to 380kg/m2s; heat flux of 3 and 12kW/m2; and a saturation temperature of 48oC. The variations of refrigerant mass flux, heat flux with condensation heat transfer performances were obtained. The comparison shows that the heat transfer coefficients of propane are higher than those for R32, R22 and R410A. The different thermophysical properties of the four refrigerants result in the heat transfer coefficient differences.
Flow condensation heat transfer coefficient of R410A in the multiport minichannels
Pham Quang Vu,Kwang-Il Choi,Jong-Taek Oh,Honggi Cho,Taehun Kim,Jungho Kim,Jaeyoung Choi 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.열공학 No.-
The flow condensation heat transfer characteristics of R410A in the multiport minichanel heat exchanger are presented. The test section is an extruded multiport aluminum tubes with the seven rectangular channels with hydraulic diameter of 1.14mm. The heat exchanger was designed as the counter flow tube heat exchanger with refrigerant flowing in the inner tube and the outer tube of heat exchanger. The experiment is performed at the heat flux between 3 and 15 kW/㎡, mass flux of refrigerant between 50 and 400kg/㎡ s and saturations temperature at 48℃. The effect of heat flux, mass flux, and vapor qualities on the heat transfer coefficient and frictional pressure gradient are discussed.