Unless the flow pattern is rearranged as in the case of homogenisation , then many instruments could never be expected to perform satisfactorily. In brief, there exist four different types of multiphase flow models, which can be categorised as follows. In 1915, Wilhelm Nusselt made significant contributions to convective heat transfer and introduced what is referred to as the Nusselt number that is a dimensionless convective heat transfer coefficient Çengel, 2003. They include surface tension, wetting, dispersion, coalescence, body forces and heat flux effects. Future Needs 312 References 312 Chapter 10. Different investigators used different coordinates for their maps e. The solid phase is incompressible and has non-deformable interfaces with the surrounding fluids.
Main Criteria for the Classification of Flow Loops 308 9. Both established and novel technologies suitable to measure the flow rates of gas, oil and water in a three-phase flow are reviewed and assessed within this book. Little information exists on four-phase flows of this type, though there have been some studies on horizontal pipeline transport of gas—slurry mixtures Heywood and Richardson, 1978 and Heywood and Richardson, 1980. Elemental Analysis Chapter 5 Current Status and Limitations of Multiphase Flow Metering 5. Until then, researchers had to write their own codes to perform fluid dynamics calculations. Wavy flow As the gas velocity is increased in stratified flow, waves are formed on the gas—liquid interface giving the wavy or stratified-wavy flow regime.
On the other hand, if different chemical substances co-exist, the flow is usually referred to as multicomponent. Churn flow At higher flow velocities, the slug flow bubbles breakdown leading to an unstable flow regime in which there is, in wide bore tubes, an oscillatory motion of the liquid, hence the name churn flow. The lessons learned about the practical reliability, accuracy and use of the available technology is discussed. The lessons learned about the practical reliability, accuracy and use of the available technology is discussed. Flow Loops for Validating and Testing Multiphase Flow Meters 306 9.
Other studies of liquid—liquid flow include those of Hasan and Kabir 1988 and Martinez et al. Semi-slug flow A number of authors have distinguished this regime in which there are large often frothy surface waves signifying a large fluctuation in liquid delivery along the pipe, though the waves in this case do not touch the top of the tube. Von der Benutzung der OverDrive Media Console raten wir Ihnen ab. The phases present in a multiphase flow are composed of: 1. An example of this would be the case of bubbly flow, which might exist in a transient sense at high void fractions, with the transition to slug flow being delayed. Regrettably we cannot fulfill eBook-orders from other countries. Sie benötigen eine sowie eine.
In 1732, Hermann Boerhaave observed that a water drop does not immediately vaporise when deposited on metal that is hotter than the boiling temperature of water. Gases, where the phase is compressible and deformable. Those technologies already implemented in the various commercial meters are evaluated in terms of operational and economical advantages or shortcomings from an operator point of view. However, it is not certain whether this effect would also occur in four-phase flows. Very small variations in pipe inclination can cause important variations in the flow pattern map of a given mixture, all the rest staying the same. Reserves Estimation and Metering Uncertainty 10. These flows largely depend on the nature of the constituents and their relative distribution.
. Here, the flow is a mixture of butane liquid, water liquid, ice particles and butane vapour. Both established and novel technologies suitable to measure the flow rates of gas, oil and water in a three-phase flow are reviewed and assessed within this book. Furthermore, the solids may agglomerate into larger lumps, particularly if they are preferentially wetted by the oil phase. Key Multiphase Flow Metering Techniques 58 4. Plug flow Horizontal plug flow is characterised by the same bullet-shaped bubbles as those found in vertical flows. Options for Measurement 51 3.
Introduction to Multiphase Flow 1. Wet Gas Metering Applications 240 6. Current status and limitation of multiphase flow metering. In what follows, a description of the main flow regimes that characterise gas—liquid, liquid—liquid, gas—liquid—liquid and solid—liquid—liquid—gas flows is presented. When pipes are inclined, the same breadth of flow regimes occurs as those illustrated in Figure 1. The flow patterns are more complex as is illustrated by Figure 1. So far, many alternative metering systems have been developed, but none of them can be referred to as generally applicable or universally accurate.
Sie benötigen eine und die Software kostenlos. This phenomenon was claimed to be due to an increase in viscosity resulting from the emulsification of the oil—water mixture. The simplest case of multiphase flow is that of a two-phase flow in which the same pure component is present in two different phases. An example here is annular flow, where very long pipe lengths are required to reach equilibrium between entrainment and deposition of droplets. Flow Loops for Validating and Testing Multiphase Flow Meters. Usually, some of the liquid phase is entrained as small droplets in the core; at high flows, it is also common for bubbles of gas to be entrained in the liquid film. Non-Conventional Multiphase Flow Metering Solutions.