Title: Theoretical and empirical study of single-substance, upward two-phase flow in a constant-diameter adiabatic pipe

Abstract

A scheme is developed to describe the upward flow of a two-phase mixture of a single substance in a vertical adiabatic constant area pipe. The scheme is based on dividing the mixture into a homogeneous core surrounded by a liquid film. This core may be a mixture of bubbles in a contiguous liquid phase, or a mixture of droplets in a contiguous vapor phase. The core is turbulent, whereas the liquid film may be laminar or turbulent. The working fluid is Dichlorotetrafluoroethane CClF/sub 2/-CClF/sub 2/ known as refrigerant 114 (R-114); the two-phase mixture is generated from the single phase substance by the process of flashing. In this study, the effect of the Froude and Reynolds numbers on the liquid film characteristics is examined. An expression for an interfacial friction coefficient between the turbulent core and the liquid film is developed; it is similar to Darcy's friction coefficient for a single phase flow in a rough pipe. Results indicate that for the range of Reynolds and Froude numbers considered, the liquid film is likely to be turbulent rather than laminar. The study also shows that two-dimensional effects are important, and the flow is never fully developed either in the film ormore » the core. In addition, the new approach for the turbulent film is capable of predicting a local net flow rate that may be upward, downward, stationary, or stalled. An actual steam-water geothermal well is simulated. A similarity theory is used to predict the steam-water mixture pressure and temperature starting with laboratory measurements on the flow of R-114. Results indicate that the theory can be used to predict the pressure gradient in the two-phase region based on laboratory measurements.« less

Authors:

Laoulache, R N; Maeder, P F; DiPippo, R

Publication Date:

Fri May 01 00:00:00 EDT 1987

Research Org.:

Brown Univ., Providence, RI (USA). Div. of Engineering

OSTI Identifier:

6050946

Report Number(s):

DOE/SF/15548-T12
ON: DE87014028

DOE Contract Number:  

AC03-85SF15548

Resource Type:

Technical Report

Resource Relation:

Other Information: Thesis (Ph.D.). Portions of this document are illegible in microfiche products. Thesis. Submitted by R.N. Laoulache

Country of Publication:

United States

Language:

English

Subject:

15 GEOTHERMAL ENERGY; PIPES; TWO-PHASE FLOW; MATHEMATICAL MODELS; FLUID FLOW; FREONS; FRICTION; GEOTHERMAL WELLS; SIMULATION; TURBULENT FLOW; VOIDS; HALOGENATED ALIPHATIC HYDROCARBONS; ORGANIC COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; WELLS; Geothermal Legacy