| Title |
Cooling Heat Transfer Characteristics of CO2 on Tube Geometry of Inclined Helical Coil Type Gas Coolers |
| Authors |
손창효(Chang-Hyo Son) ; 오후규(Hoo-Kyu Oh) |
| Keywords |
이산화탄소 급탕기 ; 가스냉각기의 설계 ; 이산화탄소의 열전달 ; 헬리컬 코일형 열교환기 CO2 heat pump ; Gas cooler ; Heat transfer coefficient of CO2 ; Inclined helical coil type heat exchanger |
| Abstract |
The cooling heat transfer coefficient of CO2 (R-744) for tube and coil diameter (CD), inclined angle of tube and coil pitch of inclined helical coil type copper tubes were inves-tigated experimentally. The main components of the refrigerant loop are a receiver, a variable- speed pump, a mass flow meter, a pre-heater and a inclined helical coil type gas cooler (test section). The test section consists of a smooth copper tube of 2.45 and 4.55mm inner diameter (ID). The refrigerant mass fluxes were varied from 200 to 800[kg/m2s] and the inlet pre-ssures of gas cooler were 7.5 to 10.0[MPa]. The heat transfer coefficients of CO2 in inclined helical coil tube with 2.45mm ID are 5∼10.3% higher than those of 4.55mm ID. The heat transfer coefficients of 41.35mm CD are 8∼32.4% higher than those of 26.75mm CD. Comparison be-tween 45° and 90° of coil angle, the heat transfer coefficients of 45° are higher than those of 90°. For coil pitch of gas cooler, the heat transfer coefficients of inclined helical coil gas cooler with coil pitch of 5 mm are similar to those of 10 and 15mm. |