Use of the mechanical energy balance for two-phase flow

AIChE Journal ◽  
1961 ◽  
Vol 7 (1) ◽  
pp. 174-174 ◽  
Author(s):  
H. S. Isbin ◽  
Yung Sung Su
Keyword(s):  
Energy Balance ◽  
Two Phase Flow ◽  
Mechanical Energy ◽  
Phase Flow ◽  
Two Phase

Effect of Branch Orientation on Annular Two-Phase Flow in T-Junctions

1996 ◽  
Vol 118 (1) ◽  
pp. 166-171 ◽  
Author(s):  
F. Peng ◽  
M. Shoukri ◽  
A. M. C. Chan
Keyword(s):  
Annular Flow ◽  
Two Phase Flow ◽  
Mechanical Energy ◽  
Phase Flow ◽  
Two Phase ◽  
Experimental Conditions ◽  
Present Test ◽  
Modelling Studies ◽  
Pressure Changes ◽  
Energy Balances

Experimental data on dividing steam-water two-phase annular flow in T-junctions with horizontal inlet and downwardly inclined branches were obtained. The experiments were performed under experimental conditions which have not been examined before. The branch orientation was found to be a significant parameter affecting phase redistribution in the junction. Increasing the downward inclination of the branch was found to reduce the degree of phase separation in the junction under the present test conditions. This is caused by the nonuniform distribution of the liquid film thickness associated with the horizontal inlet annular flow. The phase redistribution data were compared with available models. The need for additional modelling studies was evident. The pressure changes of two-phase flow in the junction were closely correlated with the phase redistribution phenomenon. The data on pressure changes in the junction were correlated using simple models based on momentum and mechanical energy balances.

Modeling and Validation of a Two-Phase Flow Valve for Expanders in Waste Heat Recovery

2020 ◽  
Vol 13 (3) ◽  
Author(s):  
Fabian Schweizer ◽  
Marius Fürst ◽  
Georg Wachtmeister
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Two Phase Flow ◽  
Waste Heat ◽  
Mechanical Energy ◽  
Dynamical Behavior ◽  
Measurement Data ◽  
Working Fluid ◽  
Phase Flow ◽  
Two Phase

Abstract Waste heat recovery is a promising method to reduce fuel consumption and CO2 emissions in heavy-duty vehicles. An organic Rankine cycle (ORC) is used to convert the thermal energy of the exhaust gases into useable energy to support the power train. A key component of the ORC is the expansion machine where the conversion of thermal into mechanical energy takes place. In the case of volumetric expansion machines such as axial piston expanders, lubrication oil is mixed in with the working fluid to reduce friction and increase the component durability. However, the presence of oil also affects both the efficiency and the fluid dynamical behavior inside the expander. To implement a one-dimensional simulation model that considers the oil influence, a continuous flow approach is selected. Particular attention is dedicated to the inlet and outlet valve modeling, as these have to account for two-phase flow and multicomponent fluid mixtures. A valve model is built up in the simulation environment dymola based on the homogeneous nonequilibrium (HNE) approach. A virtual one-cylinder test bench is set up to calibrate and validate the model. The simulation results show good correspondence with the measurement data.

Design of a Large and Versatile Two-Phase Flow Facility for Transient Studies in Pipes

2016 ◽  
Author(s):  
Geanette Polanco ◽  
José Da Paixao ◽  
Antonio Vidal ◽  
Orlando Aguillón
Keyword(s):  
Test Section ◽  
Modular Design ◽  
Two Phase Flow ◽  
Mechanical Energy ◽  
Operating Conditions ◽  
Test Facility ◽  
Phase Flow ◽  
Two Phase ◽  
System Failures ◽  
Pipe System

Frequent interruptions of pipe flows is a common situation that has to be addressed by the industry working with single and two-phase flows. These interruptions generate abrupt changes in speed and therefore changes in the pressure inside the process pipe that could create major hazardous operating conditions or even produce system failures. In terms of two-phase or multiphase flow phenomenon, there is a real need for experimental data to support the increasing concern about determining reliability of pipe system, as well as, risk assessment concerning environmental hazards due to pipe system failures. Here after, the design and construction of a large and versatile test facility to study transient performance after a rapid closure occurs, is presented. The final goal of this facility is to create the possibility of having a database corresponding to the phenomenon known as water hammer for both single and two-phase flow. Different two-phase flow patterns can be simulated for the test. The facility is located on the premises of the Laboratory of Conversion of Mechanical Energy of the Simon Bolivar University, Caracas, Venezuela (LABCEM-USB). The facility consists of an instrumented closed flow loop that works with water and air at distinct flow proportions. The facility can be described as a group of seven interconnected sub-systems or modules that connect all the required capabilities. The Sub-systems are: liquid system, gas system, mixing system, pneumatic system, instrumentation system, electrical system and the test section. This modular design allows identification of the main components as individual subtask for the designing process. The test section is made in transparent material for visualization and it can be modified into different geometrical arrangements or configurations using different angles of inclination. Both static and dynamic pressure before and after an imminent closing of the valves for specific conditions of flow. The capability of selection of the inclination and the geometrical configuration of the test section (inverted “U” shape or linear pipe section) makes a unique air/water two-phase flow facility. The design represents a compact but versatile capability for evaluating test sections from a horizontal to a vertical position of the pipe. Initial results presented here show the pressure level achieved for different configurations.

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