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Segregated Flow Pattern: This Is One in Which The Phases: Provokes The Liquid Phase To Be Located at The Bottom

The document describes various patterns and methods for the multiphase flow of gases and liquids in pipelines. It describes segregated, stratified, wavy, and annular flow patterns. It also describes intermittent, distributed flow and their subtypes. Then, it presents several empirical correlations and mechanistic models used to predict pressure drops, including the correlations by Beggs & Brill, Dukler, AGA, Flanigan, HTFS, Oliemans, and the unified two-phase model.

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10 views4 pages

Segregated Flow Pattern: This Is One in Which The Phases: Provokes The Liquid Phase To Be Located at The Bottom

The document describes various patterns and methods for the multiphase flow of gases and liquids in pipelines. It describes segregated, stratified, wavy, and annular flow patterns. It also describes intermittent, distributed flow and their subtypes. Then, it presents several empirical correlations and mechanistic models used to predict pressure drops, including the correlations by Beggs & Brill, Dukler, AGA, Flanigan, HTFS, Oliemans, and the unified two-phase model.

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SEGREGATED FLOW PATTERN: THIS IS ONE IN WHICH THE PHASES

They are mostly separated.


STRATIFIED FLOW: THIS FLOW REGIME
PRESENTS WHEN THE SURFACE SPEEDS
THE LIQUID AND VAPOR ARE LOW. THE GRAVITY
PROVOKES THE LIQUID PHASE TO BE LOCATED AT THE BOTTOM
THERE IS A PIPE AND A SMOOTH INTERFACE BETWEEN IT
LIQUID AND VAPOR PHASE.
WAVY FLOW: THIS FLOW REGIME EXISTS
WHEN WAVES FORM ON THE INTERFACE BETWEEN
LIQUID AND VAPOR. BEGINNING FROM THE FLOW
STRATIFIED, WHEN INCREASING THE SPEED OF
VAPOR, THE FLOW REGIME WILL MOVE TOWARDS THE
WAVY STRATIFIED FLOW. GRAVITY
WILL CAUSE THE LIQUID TO FLOW AT THE BOTTOM OF THE
PIPE
ANULAR FLOW: THIS FLOW REGIME EXISTS AT HIGH
SURFACE SPEEDS OF STEAM. THE LIQUID
TEND TO FLOW LIKE A RING AROUND THE
CIRCUMFERENCE OF THE PIPE. IN HORIZONTAL FLOW
THE RING WILL BE MUCH THINNER AT THE TOP
THAT IN THE BOTTOM. THE VAPOR PHASE WILL FLOW THROUGH
THE CENTER OF THE RING CAN CONTAIN SMALL ONES
Drops of liquid.
INTERMITTENT FLOW: IT IS ONE IN WHICH THE GAS AND THE
LIQUID FLOW ALTERNATELY THROUGH THE PIPE.
-FLOW BLOCK: THIS FLOW REGIME EXISTS WHEN
LARGE LIQUID WAVES, OF SHORT DURATION,
THEY ARE SEPARATED BY FLOW PERIODS
WAVY STRATEGIC. STARTING FROM THE
STRATIFIED FLOW WHEN INCREASING SPEED
PLUGS OF THE LIQUID WILL FORM ON THE SURFACE
LIQUID FOLLOWED BY A STRATIFIED FLOW
WAVY.
POTHOLE FLOW: CONSISTS OF LARGE POTHOLES
LIQUID ALTERNATED WITH GAS BUBBLES AT HIGH
SPEED.
DISTRIBUTED FLOW: IT IS CHARACTERIZED BY A PHASE THAT
FIND DISPERSED IN THE OTHER.
BUBBLE TYPE: PRESENTS DISPERSED BUBBLES INSIDE
FROM THE LIQUID PHASE.
MIST TYPE: THIS TYPE OF FLOW EXISTS AT HIGH
SURFACE SPEEDS OF STEAM AND WHEN
THE STEAM QUALITY IS HIGH. THE PIPE WOULD BE
COMPLETELY FULL OF STEAM, EXCEPT FOR
Small droplets of liquid in the form of mist.
EMPRICAL CORRELATIONS: THEY ARE EXPERIMENTAL METHODS
THAT ARE DEVELOPED SCIENTIFICALLY. THESE METHODS
THEY COULD BASE IT ON DIMENSIONAL ANALYSIS TO REACH
A universal solution.
BEGGS & BRILL CORRELATION: IT IS BASED ON WORKS
MADE WITH MIXES OF WATER AND AIR FOR DIFFERENT
CONDITIONS. IT IS EMPHASIZED TO CALCULATE THE PROPERTIES
WHAT AFFECTS PRESSURE DROPS IN FLOW
MULTIPHASIC. AMONG THE LIMITATIONS OF THE METHOD ARE
FIND, ON THE OVER PREDICTION OF LOSSES
PRESSURE IN 1 ½ INCH DIAMETER PIPES. THE
THE FLOW CHART IS BASED ON HORIZONTAL FLOW AND HAS 4
REGIMES: SEGREGATED, INTERMITTENT DISTRIBUTED AND
TRANSITION. THE TYPES OF FLOWS IN THE FIRST 3 ARE:
-SEGREGATED FLOW: WAVY, STRATIGRAPHIC AND
CANCEL.
INTERMITTENT FLOW: PLUG AND SLUG.
DISTRIBUTED FLOW: BUBBLE AND FOG.
ONCE THE FLOW REGIME HAS BEEN DETERMINED, THE
LIQUID HOLDUP FOR A HORIZONTAL PIPE IS
CALCULATED USING THE APPROPRIATE CORRELATION FOR
TAL REGIME. THE PIPE INCLINATION IS A FACTOR
APPLIED FOR THE CALCULATION OF THE 'HOLDUP'. AFTER THE
HOLDUP, A FRICTION FACTOR IS CALCULATED AND IS
DETERMINE THE PRESSURE GRADIENT.
THE PURPOSE OF THE STUDY CONDUCTED BY BEGGS & BRILL,
IT WAS DEVELOPING CORRELATIONS TO PREDICT FL
(LIQUID HOLDUP) AND FM(Friction Factor of the
MIXTURE), FOR FLUIDS WHOSE PROPERTIES ARE
KNOWN.
DUKLER, AGA, FLANIGAN: WAS DEVELOPED FOR SYSTEMS
GAS-CONDENSATE FLOW IN HORIZONTAL PIPES
AND INCLINED. THE FLOW PATTERN MAP OF TAITEL-
DUKLER CONSIDERS 5 STRATIFIED FLOW REGIMES,
WAVY, INTERMITTENT, ANNULAR AND DISPERSED BUBBLES. THE
DUKLER'S EQUATION IS USED TO CALCULATE THE
PRESSURE LOSSES DUE TO FRICTION, HOLDUP AND THE
FLANIGAN'S EQUATION IS USED TO CALCULATE THE
GRADIENT OF POTENTIAL PRESSURE.
HTFS LIQUID SLIP AND HOMOGENEOUS: THE TWO HTFS METHODS
THEY SHARE A COMMON METHOD FOR CALCULATING THE
PRESSURE GRADIENTE DUE TO FRICTION AND GRADIENTE OF
PRESSURE BY ACCELERATION, WHILE IT DIFFERS IN THE
METHOD USED TO CALCULATE THE PRESSURE GRADIENT
STATIC.
THE METHOD FIRST CALCULATES THE PRESSURE DROP BY
FRICTION FOR LIQUID AND GAS PHASES, ASSUMING THAT
THEY ARE ONLY FLOWING AT THE BASE OF THE PIPE.
OLIEMANS: A STUDY WAS DEVELOPED USING
LARGE DIAMETER PIPES THAT CARRIED
CONCENTRATES. A SIMPLE MODEL WAS INTRODUCED THAT
OBEDIENCE TO INDIVIDUAL CORRECT LIMITATIONS OF
FLOW TO PREDICT PRESSURE DROPS. THE MODEL IS
BASED ON A LIMITED AMOUNT OF 30 DATA
INCHES AT A DISTANCE OF 100 KM AT PRESSURES OF 100
BAR (1450 PSI) OR MORE. THE CORRELATION MAY BE
PRESENT INCONVENIENCES WITH DIAMETERS LESS THAN 15
INCHES AND LOW PRESSURES.
MECHANISTIC MODEL: IT IS A MATHEMATICAL MODEL THAT
EXPLAIN THE BEHAVIOR OF MULTIPHASIC FLOW IN
PIPE INCORPORATING ALL THE VARIABLES THAT ARE
INVOLVED IN THIS PHENOMENON. THE FIRST OBJECTIVE IS
DETERMINE THE FLOW PATTERN OF A GIVEN SYSTEM.
THEN, FOR EACH FLOW PATTERN A
APPROPRIATE MATHEMATICAL MODEL, WHICH PREDICTS THE
HYDRODYNAMICS OF FLOW AND HEAT TRANSFER
FOR THIS.
UNIFIED TWO-PHASE MODEL: THE UNIFIED MODEL
DE TUFFP IS A MECHANISTIC MODEL FOR PREDICTION
FLOW PATTERNS IN TRANSITION, PRESSURE GRADIENTS,
LIQUID HOLDUP AND 'SLUP' FLOW CHARACTERISTICS IN
GAS-LIQUID PIPE. THE MODEL WAS VALIDATED FOR
ALL INCLINATION ANGLES.
XIAO ET AL: THIS IS DEVELOPED FOR TWO FLOW
PHASES IN HORIZONTAL PIPES AND NEAR HORIZONTAL
(+/- 15). THE FIRST MODEL PREDICTS THE FLOW PATTERN AND
CALCULATE THE FLOW CHARACTERISTICS SUCH AS HOLDUP OF
LIQUID AND PRESSURE DROP, FOR STRATIFIED FLOW,
CIRCULAR, INTERMITTENT, AND BUBBLE. THE MODEL IS VALIDATED
WITH A DATABASE OF HORIZONTAL PIPES INCLUDING
LARGE FIELD DIAMETERS.
HOLDUP: VOLUMETRIC FRACTION OF A SECTION
SPECIFIC PIPE USED BY THE PHASE
LIQUIDATE.

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