ViewsAir is drawn into the front of the compressor. Each succeeding stage is smaller increasing velocity (recall Bernoullis equation).
Between each rotating stage is a stationary stage or stator. The stator partially converts the high velocity to pressure and directs the air to the next set of rotating blades.
The rotor imparts velocity to the air (like a fan). Each stage consists of a rotor and stator and results in a pressure increase.
Air exits the compressor and enters the diffuser. Suddenly, the air moves from a narrow passage into a wide area. By bernoulli, the air loses velocity and expands in volume and increases pressure. Now, the air is slow moving and high pressure, usually about 19:1. Fuel is injected here and the mixture is ignited by a spark. The spark causes a rapid increase in the volume of the air an combustion gases (at constant pressure).
The combustion mixture goes rearward to a nozzle which directs the gas onto the turbine blades and accelerates the gases. The gases are now high velocity, high temperature, low pressure and are used to turn the turbine. The kinetic and thermal energy of the gases are transferred the turbine blades. The turbine is multistaged to remove as much of the energy from the gas as possible.
Radial flow or centrifugal compressor- compressor draws in the entering air at the hub of the impeller and accelerates it radially outward by centrifugal force through the impeller. Reasonably efficient for high pressure ratios developed in a single stage.
Axial flow- Rotor has fixed blades which force the air rearward much like an aircraft propeller. The stator directs the air rearward to the next stage. Very much like a turbine used in reverse. Used in multistage arrangements and pressure ratios increase with the number of stages.
Can Type- Individual liners and cases mounted around the engine each with its own fuel nozzle.
Annular type- Liner consists of an undivided circular shroud extending all the way around the outside of the turbine shaft housing. The dome of the liner has small slots and holes to admit primary air. There are also holes in the dome for the fuel nozzles to extend through into the combustion area. The combustion space is formed by the inner and outer liners. The inner liner prevents flame from contacting the turbine shaft housing.
Can-annular type- Designed to deal with split spool compressor. Individual cans are placed inside an annular case. Combines the strength of annular design with the convenience of maintenance of the can. Also keeps high temperatures in the inner can.
Turbines, like compressors, consist of stator and rotor elements. Stators prepare the mass flow for harnessing of power through the turbine rotor. The nozzles take the high pressure, high-energy mixture and give it velocity for driving the rotor. Also deflects the gases to a specific angle in the direction of the turbine wheel rotation.
Rotors consist of a shaft and bladed wheel. Turbine operates at high speed
Single- Aircraft and electric power- constant speed independent of load
Split- allows the compressor to run at different speed that power turbine maximizing the efficiency of operation.
Provides the space for mounting and the motive force for driving the accessories required for the operation and control of the engine
Discuss the following accessory equipment attached at the assembly:
Fuel oil pump
Lube oil pump
Starter (pneumatic, electric, hydraulic)
Let conductor starts rotating from position 1.at this instant, the entire velocity component is parallel to the flux lines. Hence there is no cutting of flux lines by the conductor. So d@/dt at this instant is zero and hence induced emf in the conductor is also zero. As the conductor moves from position 1 to position 2, the part of the velocity component becomes perpendicular to the flux lines and proportional to that, emf gets induced in the conductor. The magnitude of such an induced emf increases as conductor moves from position 1 to 2.
- Construction And Working Principle Of Diesel Generator Pdf Online Free
- Construction And Working Principle Of Diesel Generator Pdf Online Download
- Construction And Working Principle Of Diesel Generator Pdf Online Pdf
- Construction And Working Principle Of Diesel Generator Pdf Online Online
Principle of Electric Motor and Generator - Principle of an electric generator. What are the working principles of generators and motors? - Quora - Important thing you need to understand about a DC generator. Basic construction and working of a DC Generator.| electricaleasy.com - working of DC generator.
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Diesel Engine is a compression ignition engine with diesel fuel. Usually, a diesel generator set is composed of three parts: diesel engine, AC synchronous generator and control panel. The working principle of diesel engine is that the air is compressed in the cylinder which causes the temperature to rise. Home » Marine Electrical Technology » AC Generator Working Principle. Aio software download. To obtain convenience in the construction. These laminations (also known as stampings. Otto Engine The main difference between the Diesel and Otto engine is: The burning of the fuel. • In a Gasoline engine the air/fuel mixture enters the cylinder and creates a stoichiometric homogeneous mixture, which is ignited and the flame travels from the spark and outwards to the liner. Construction of a Simplified Wood Gas Generator for Fueling Internal Combustion Engines in a Petroleum Emergency By. WHAT 1S A WOOD GAS GENERATOR AND HOW DOES IT WORK? 1.1.INTRODUCTION 1.2.PRINCIPLES OF SOLID FUEL GASIFICATION. Small amount of diesel fuel is used for ignition, a properly adjusted diesel engine can be operated. Quality improvement tools pdsa worksheet. SYNCHRONOUS GENERATORS Synchronous generators or alternators are synchronous machines that convert mechanical energy to alternating current (AC) electric energy.1 SYNCHRONOUS GENERATOR CONSTRUCTION A direct current (DC) is applied to the rotor winding of a synchronous generator to produce the rotor magnetic field.
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Construction And Working Principle Of Diesel Generator Pdf Online Free
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Between each rotating stage is a stationary stage or stator. The stator partially converts the high velocity to pressure and directs the air to the next set of rotating blades.
The rotor imparts velocity to the air (like a fan). Each stage consists of a rotor and stator and results in a pressure increase.
Air exits the compressor and enters the diffuser. Suddenly, the air moves from a narrow passage into a wide area. By bernoulli, the air loses velocity and expands in volume and increases pressure. Now, the air is slow moving and high pressure, usually about 19:1. Fuel is injected here and the mixture is ignited by a spark. The spark causes a rapid increase in the volume of the air an combustion gases (at constant pressure).
The combustion mixture goes rearward to a nozzle which directs the gas onto the turbine blades and accelerates the gases. The gases are now high velocity, high temperature, low pressure and are used to turn the turbine. The kinetic and thermal energy of the gases are transferred the turbine blades. The turbine is multistaged to remove as much of the energy from the gas as possible.
Axial flow- Rotor has fixed blades which force the air rearward much like an aircraft propeller. The stator directs the air rearward to the next stage. Very much like a turbine used in reverse. Used in multistage arrangements and pressure ratios increase with the number of stages.
Rotors consist of a shaft and bladed wheel. Turbine operates at high speed
Discuss the following accessory equipment attached at the assembly:
Fuel oil pump
Lube oil pump
Starter (pneumatic, electric, hydraulic)
It is known that the electric supply used now-a-days for commercial, as well as domestic purposes, is of alternating type.Similar to d.c machines, the a.c machines associated with alternating voltages, are also classified as generators and motors.
Machines generating ac EMF are called alternators or synchronous generators. While the machines accepting input from a.c supply to produce a mechanical output are called synchronous motors.Both these machines work at a specific constant speed called synchronous speed and hence is general called synchronous machines.
It is seen that in the case of a d.c generator, basically, the nature of the induced e.m.f in the armature conductors is of alternating type. By using commutator and brush assembly it is converted to d.c and made available to the external circuit.
If commutator is dropped from a d.c generator and induced e.m.f is tapped from an armature directly outside, the nature of such emf will be alternating. Such a machine without a commutator, providing an a.c emf to the external circuit is called an alternator.
If commutator is dropped from a d.c generator and induced e.m.f is tapped from an armature directly outside, the nature of such emf will be alternating. Such a machine without a commutator, providing an a.c emf to the external circuit is called an alternator.
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Construction of Synchronous generator or alternator:
In Synchronous generator or alternators the stationary winding is called 'stator' while the rotating winding is called 'Rotor'.
The stator in the synchronous generator is a stationary armature.This consists of a core and the slots to hold the armature winding similar to the armature of a d.c generator.The stator core uses a laminated construction.It is built up of special steel stampings insulated from each other with varnish or paper.The laminated construction is basically to keep down eddy current losses.
Generally choice of material is steel to keep down hysteresis losses.The entire core is fabricated in a frame made of steel plates.The core has slots on its periphery for housing the armature conductors.The frame does not carry any flux and serves as the support to the core.Ventilation is maintained with the help of holes cast in the frame.
Generally choice of material is steel to keep down hysteresis losses.The entire core is fabricated in a frame made of steel plates.The core has slots on its periphery for housing the armature conductors.The frame does not carry any flux and serves as the support to the core.Ventilation is maintained with the help of holes cast in the frame.
There are two types of rotors used in the synchronous generators or alternators:
2)Smooth cylindrical rotor
1) Salient pole rotor:
1) Salient pole rotor:
This is also called projected pole type as all the poles are projected out from the surface of the rotor.The poles are built up of thick steel laminations.The poles are bolted to the rotor as shown in the figure.The pole face has been given a specific shape.The field winding is provided on the pole shoe.These rotors have large diameters and small axial lengths.
The limiting factor for the size of the rotor is the centrifugal force acting on the rotating member of the machine. As the mechanical strength of salient pole type is less, this is preferred for low-speed alternators ranging from 125 r.p.m to 50 r.p.m.The prime movers used to drive such rotor are generally water turbines and I.C. engines.
This is also called non-salient type or non-projected pole type or round rotor.This rotor consists of a smooth solid steel cylinder, having a number of slots to accommodate the field coil.These slots are covered at the top with the help of steel or manganese wedges.The unslotted portions of the cylinder itself act as the poles.The poles are not projecting out and the surface of the rotor is smooth which maintains a uniform air gap between stator and rotor.
These rotors have small diameters and large axial lengths.This is to keep peripheral speed within limits.The main advantage of this type is that these are mechanically very strong and thus preferred for high-speed alternators ranging between 1500 to 3000 r.p.m. Such high-speed alternators are called 'turbo-alternators'.The prime movers used to drive such type of rotors are generally steam turbines, electric motors.
The alternators work on the principle of electromagnetic induction. When there is a relative motion between the conductors and the flux, emf gets induced in the conductors. The dc generators also work on the same principle. The only difference in the practical synchronous generator and a dc generator is that in an alternator the conductors are stationary and field is rotating. But for understanding, the purpose we can always consider relative motion of conductors w.r.t the flux produced by the field winding.
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Consider a relative motion of a single conductor under the magnetic field produced by two stationary poles. The magnetic axis of two poles produced by field is vertical, shown dotted in below figure.
Let conductor starts rotating from position 1.at this instant, the entire velocity component is parallel to the flux lines. Hence there is no cutting of flux lines by the conductor. So d@/dt at this instant is zero and hence induced emf in the conductor is also zero. As the conductor moves from position 1 to position 2, the part of the velocity component becomes perpendicular to the flux lines and proportional to that, emf gets induced in the conductor. The magnitude of such an induced emf increases as conductor moves from position 1 to 2.
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At position 2, the entire velocity component is perpendicular to the flux lines. Hence there exists cutting of the flux lines. And at this instant, the induced emf in the conductor is at its maximum. As the position of conductor changes from 2 to 3, the velocity component perpendicular to the flux starts decreasing and hence induced emf magnitude also starts decreasing.At position 3, again the entire velocity component is parallel to the flux lines and hence at this instant induced emf in the conductor is zero.
As the conductor moves from 3 to 4, velocity component perpendicular to the flux lines again starts increasing. But the direction of velocity component now is opposite to the direction of velocity component existing during the movement of the conductor from position 1 to 2.Hence an induced emf in the conductor increase but in the opposite direction.
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At position 4, it achieves maxima in the opposite direction, as the entire velocity component becomes perpendicular to flux lines. Again from position 4 to 1, induced emf decreases and finally at the position again becomes zero. This cycle continues as conductor rotates at a certain speed. So if we plot the magnitudes of the induced emf against the time, we get an alternating nature of the induced emf shown figure above. This is the working principle of Synchronous generator or Alternator.