Properties of Petroleum Liquids Mass:

the amount of matter contained in a body

the amount of the inertial property of that body meaning its resistance to the change of motion

Volume

the space occupied by a particular mass

dependent upon temperature and pressure

changes minutely with temperature

Density

depends on liquid and temperature

lower density --> higher temp

higher density --> higher prep

Thermal expansion
liquids expand as their temperature rises

density decrease with temperature increase :the decreasing ratio with increasing temperature is referred to as thermal expansion coefficient

density increase with pressure increase and volume decrease: the increasing ratio with the increasing pressure is referred to as the bulk modulus

Compressibility : the extent to which a fluid can be compressed. change in pressure--> change in volume
it is the main cause of pressure surge in pipeline systems
Bulk Modulus k: defines the compressibility of a liquid. the higher the bulk modulus the stiffer the liquid.
(lecture 2 slide 13)

Specific Gravity and API Gravity
SG: measure of how heavy the liquid is compared with water. some change with pressure and temperature
equations ( lecture 2 slide 16-17)

Viscosity Newtonian Vs. Non-Newtonian
viscosity:

relative measure of resistance to flow

measure of friction between adjacent layers of a flowing fluid

velocity gradient is caused by viscosity.
Sheer Stress : the frictional forces within a fluid that oppose the flow

function of pressure

Sheer Rate: the velocity with which an individual layer moves relative to neighboring layers

function of geometry and average velocity of a fluid

Newtonian Fluids
dynamic/absolute viscosity is constant
Non-newtonian fluids

Time dependent

Time independent

Viscoelastic

VAPOR PRESSURE
the pressure that maintains a liquid in equilibrium at a given temperature.

it is a measure of volatility

Pipeline transportation of hydrocarbon liquids requires that a minimum pressure greater than the vapor pressure be maintained throughout the pipeline to avoid:

Slack flow

two-phase flow conditions

avoid cavitation in pumps

REMARK: Cavitation occurs when the pressure at the pump is below the Vapor pressure. Pressure must be ABOVE the vapor pressure at all points in time

True Vapor Pressure:
the equilibrium partial pressure exerted by a volatile organic fluid as a function of pressure.
Evaporation losses in tankage systems are related to the TVP
partial vapor pressure

Reid Vapor Pressure:
absolute vapor pressure

For liquid hydrocarbons having a vapor pressure greater than the atmospheric pressure at base temperature, the base pressure must be the equilibrium vapor pressure at base temperature.

FLUID PROPERTIES AFFECTING MEASURMENT ( lecture 2 slides 34-35)

	Criado por Yasmina Moussa quase 9 anos atrás

Normal-level (N-level) Transmission and Storage Notas sobre Hydrocarbon Liquid Properties , criado por Yasmina Moussa em 26-10-2015.

Hydrocarbon Liquid Properties