naa a22 4500 510821057 CHVBK 20180411083532.0 cr unu---uuuuu 180411e20130501xx s 000 0 eng 10.1007/s11814-013-0024-9 doi (NATIONALLICENCE)springer-10.1007/s11814-013-0024-9 Heat transfer property of refrigerant-oil mixture in a flooded evaporator: The role of bubble formation and oil retention [Elektronische Daten] [Kyoung-Min Koo, Soowon Lee, Sung-Gyu Kim, Young-Man Jeong, Jae-Keun Lee, Nae-Hyun Park, Byung-Chul Na, Yoon-Jae Hwang, Byung-Soon Kim, Joon-Hyun Hwang, Soo Kim] We examined the effect of oil retention on the heat transfer performance of a shell-and-tube-type evaporator which had 26 inner tubes and was filled with the refrigerant R-134a. The refrigerant was boiled on the surface of the inner tubes in the evaporator, while chilled water circulated through these tubes. An experimental apparatus was designed to measure both the pressure and temperature profiles at the inlet and outlet of the flooded evaporator. Four windows were installed for observing the operation of the flooded evaporator. A series of experiments were carried out under the following conditions: the refrigerant saturation temperature, 5 °C; refrigerant inlet quality, 0.1; heat fluxes from water to the refrigerant, 5-7 kW/m2. The concentration of the oil retained in the refrigerant was then varied up to approximately 10% to observe the effect on the heat transfer performance of the flooded evaporator. Increasing the oil content (i.e., increasing the concentration up to a maximum of approximately 10%) in the refrigerant R134a did not lead to any appreciable reduction in the overall heat transfer coefficient of a flooded evaporator with multiple-innertubes. When the oil concentration in the refrigerant was approximately 10%, the heat transfer degradation in the case of the flooded evaporator with multiple-inner-tubes was approximately 11%, which was found to be much smaller than the heat transfer degradation in the case of a flooded evaporator with a single-tube (26-49%). This observation suggested that the oil retained in the refrigerant did not significantly deteriorate the heat transfer performance of the flooded evaporator, presumably because the presence of tube bundles promoted forced convection by agitating bubbles. Korean Institute of Chemical Engineers, Seoul, Korea, 2013 Flooded Evaporator nationallicence Shell-and-tube-type Heat Exchanger nationallicence R-134a/Oil Mixture nationallicence Enhanced Tube nationallicence Heat Transfer Degradation nationallicence Koo Kyoung-Min School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut Lee Soowon Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut Kim Sung-Gyu School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut Jeong Young-Man School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut Lee Jae-Keun School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut Park Nae-Hyun Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut Na Byung-Chul Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut Hwang Yoon-Jae Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut Kim Byung-Soon Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut Hwang Joon-Hyun Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut Kim Soo Department of Nanomechatronics Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut Korean Journal of Chemical Engineering Springer US; http://www.springer-ny.com 30/5(2013-05-01), 1029-1033 0256-1115 30:5<1029 2013 30 11814 https://doi.org/10.1007/s11814-013-0024-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11814-013-0024-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Koo Kyoung-Min School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut NATIONALLICENCE 700 1- Lee Soowon Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut NATIONALLICENCE 700 1- Kim Sung-Gyu School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut NATIONALLICENCE 700 1- Jeong Young-Man School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut NATIONALLICENCE 700 1- Lee Jae-Keun School of Mechanical Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut NATIONALLICENCE 700 1- Park Nae-Hyun Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut NATIONALLICENCE 700 1- Na Byung-Chul Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut NATIONALLICENCE 700 1- Hwang Yoon-Jae Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut NATIONALLICENCE 700 1- Kim Byung-Soon Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut NATIONALLICENCE 700 1- Hwang Joon-Hyun Air Conditioning Energy Company, LG Electronics, 391-2, Gaeumjeong-dong, 641-711, Changwon City, Gyeongnam, Korea aut NATIONALLICENCE 700 1- Kim Soo Department of Nanomechatronics Engineering, Pusan National University, San 30, Jangjeon-dong, Geumjung-gu, 609-735, Busan, Korea aut NATIONALLICENCE 773 0- Korean Journal of Chemical Engineering Springer US; http://www.springer-ny.com 30/5(2013-05-01), 1029-1033 0256-1115 30:5<1029 2013 30 11814 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer