Post on 22-Feb-2016
description
transcript
Units Three and FiveUnits Three and Five
Energy Transmission Using Energy Transmission Using FluidsFluids
Both Liquids and Gases qualify as fluids since each takes the shape of its container and will produce flow.
However, gases compress and liquids are relatively incompressible.
Liquids and GasesLiquids and Gases
A molecule consists of two or more atoms in A molecule consists of two or more atoms in chemical combination.chemical combination.
Liquid MoleculesLiquid Molecules Gaseous Gaseous MoleculesMolecules
Molecular EnergyMolecular Energy
Molecular energy is the movement of Molecular energy is the movement of molecules within a substancemolecules within a substance
Molecular energy is affected by temperature.Molecular energy is affected by temperature.
Fluids take the shape of their Fluids take the shape of their containerscontainers
Gases and Heat EnergyGases and Heat Energy
Gas Temperature, Pressure, Gas Temperature, Pressure, Compression, and InefficiencyCompression, and Inefficiency
Boyles Law of Gas CompressionBoyles Law of Gas Compression
Hydraulic Transmission of EnergyHydraulic Transmission of Energy
Pneumatic Transmission of EnergyPneumatic Transmission of Energy
Hydraulic AccumulatorHydraulic Accumulator
Positive Displacement PumpPositive Displacement Pump
Positive Displacement CompressorPositive Displacement Compressor
Pump TypesPump Types
1. Gear
2. Piston
Pump TypesPump Types
3. Vane
Pump TypesPump Types
Resistance and PressureResistance and PressureAny influence that restricts the movement of fluid is Any influence that restricts the movement of fluid is resistance and will effect pressure. resistance and will effect pressure.
The systematic relationship between resistance The systematic relationship between resistance and pressure is directly proportional.and pressure is directly proportional.
Heat generation in FluidsHeat generation in Fluids
When energy is consumed to overcome resistance, When energy is consumed to overcome resistance, energy changes form. The energy is transformed energy changes form. The energy is transformed into heat energy.into heat energy.
Examples:Examples:
Heat from lightingHeat from lighting
Heat from machine bearings.Heat from machine bearings.
Heat from friction Heat from friction
ViscosityViscosityViscosity is the measure of a liquids resistance to Viscosity is the measure of a liquids resistance to
flow.flow.
As a “liquid” takes on heat, its viscosity will As a “liquid” takes on heat, its viscosity will change.change.
Measuring ViscosityMeasuring ViscosityViscosity is measured in units called Saybolt Universal Viscosity is measured in units called Saybolt Universal Seconds or SSU. Seconds or SSU.
This is the time it takes for a liquid to flow through an This is the time it takes for a liquid to flow through an orifice of a exact size when the fluid is at a certain orifice of a exact size when the fluid is at a certain temperature.temperature.
Viscosity and Friction Viscosity and Friction generate Heatgenerate Heat
A liquid resists movement, this is resistance.
A sharp bend or turn is resistance.
Fluid moving too fast through through a conductor generates heat because of resistance.
The rate of movement of fluid per foot is referred to as velocity.
Viscosity and Friction Viscosity and Friction generate Heatgenerate Heat
(continued)
Maximum velocities for fluidsMaximum velocities for fluids
Oil: 10 to 30 feet per second depending on pressure. 15 fps is a general rule.
Womack, Vol1, page 37.
Gas: 1100 fps, “critical velocity.”
For oil velocity: GPM x .3208/AreaFor oil velocity: GPM x .3208/Area
Pressure DifferentialPressure Differential
When ever a fluid is moving through a conductor When ever a fluid is moving through a conductor and there exists a difference between pressure and there exists a difference between pressure between any two points, the difference is called a between any two points, the difference is called a pressure differential or “delta-P.”pressure differential or “delta-P.”
General System DesignGeneral System Design
Avoid sharp turns, obstructions, and anything Avoid sharp turns, obstructions, and anything that would disturb flow.that would disturb flow.
Also consider pipe size.Also consider pipe size.