The numerical calculation of heat transfer performance for annular flow of liquid nitrogen in a vertical annular channel

✍ Scribed by Shufeng Sun; Yuyuan Wu; Rongyi Zhao

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 226 KB
• Volume: 41
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/s0011-2275(01)00058-3

✦ Synopsis

According to a separated phase ¯ow model for vertical annular two-phase ¯ow in an annular channel, the liquid ®lm thickness, distributions of velocities and temperatures in the liquid layer are predicted in the range of heat ¯uxes: 6000±12000 W=m 2 , mass ¯ux: 500±1100 kg=m 2 s. The pressure drop along the ¯ow channel and heat transfer coecient are also calculated. The liquid ®lm thickness is in the order of micrometers and heat transfer coecient is 2800±7800 W=m 2 K of liquid nitrogen boiling in narrow annular channels. The measured heat transfer coecient is 29% higher than the calculated values. With the mass ¯ux increasing and the gap of the annular channel decreasing, pressure drop and heat transfer coecient increase.