Two-phase flow pressure drop and heat transfer characteristics of refrigerants in vertical tubes

Technical Report · Thu Jan 01 04:00:00 EST 1976

OSTI ID:4065807

Jallouk, P A

Research was undertaken to study the two-phase flow characteristics of refrigerants in vertical tubes. An experimental study was made of the flow regime, pressure drop, heat transfer coefficient, and critical heat flux of R-114 boiling in a 0.785-in.-ID, 10-ft-long vertical tube. The boiling temperature was varied in the range of 100 to 250$sup 0$F for all tests except the heat transfer coefficient runs where the range 100 to 200$sup 0$F was studied. The mass flux range was 0.12 less than or equal to G less than or equal to 3.5 x 10$sup 6$ lbm/ hr-ft$sup 2$. Analytic and experimental techniques were used to investigate the heat transfer and pressure drop characteristics. An improvement in the prediction of the system behavior was obtained and the discrepancies between the behavior of boiling refrigerants and other working fluids have been explained. New equations were developed or existing ones verified so that design engineers requiring information on the two-phase flow characteristics of refrigerants in vertical tubes at operating conditions not too different from those studied here may use the equations presented here. The limitations of each equation are also presented. Recommendations for further investigation are given. (auth)

• Research Organization: Oak Ridge Gaseous Diffusion Plant, Tenn. (USA)
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-33-023232
• OSTI ID: 4065807
• Report Number(s): K--1864
• Country of Publication: United States
• Language: English

Related Subjects

*CHLORINATED ALIPHATIC HYDROCARBONS-- TWO-PHASE FLOW
*FLUORINATED ALIPHATIC HYDROCARBONS-- TWO-PHASE FLOW
*TWO-PHASE FLOW-- PRESSURE DROP
420400* --Engineering--Heat Transfer & Fluid Flow
CRITICAL HEAT FLUX
N42300* --Engineering--Heat Transfer & Fluid Flow
REFRIGERATION
TUBES