Prime Movers Flashcards
In bearing boars, the measurements should be taken and recorded. In These Positions
Vertically and horizontally.
You measure a bore in.____ positions determine if the main bearing Bores are Circular without taper and the correct size. The size ensures that the bearing has the correct crush.
3
Some of the methods used to treat the inside of cylinder liners in order to reduce the rate of wear are
.Induction hardening
.Hard chrome
.Nitriding
________ Are sleeves that fit inside the cylinder boar and do not contact the engine coolant.
Dry liners
_____ Are in contact with the coolant and form part of the water jacket.
wet liners,
_____ Have cooling fins that surround the Outer diameter of the cylinder.
Air cooled liners
_____ Liners that feature porting on them near the middle of the cylinder are used on 2 stroke engines.
Porting
It is normal for liners to have Ware concentrated in a Pacific area. The tendency is for the liner to wear in A.______
Tapered fashion
Most of the wear on a liner occurs towards the
Top of the liner near the upper limit of the ring travel
Most of the wear on the liner occurs on the
major thrust side when cylinder pressure and temperature are at maximum.
______ converts the downward linear motion of the piston to usable rotary motion
Crankshaft
_______ is used when a cylinder has a ridge above the ring travel
Ridge reamer
Removing the ridge on a cylinder under _______ in diameter is accomplished with a hand operated ridge reamer
6in (150mm)
A pattern 40* to 60* honed in a cylinder is called
Cross hatch pattern
Cross hatch pattern is
40 to 60 degrees
After honing or deglazing use a _______________ to clean the cylinder
Bristle brush and hot soapy water
Do not use __________ to clean cylinders because it it do not thoroughly flush the material and abrasive from microscopic grooves
Solvents
To check cleanliness of the bore ________
Wipe with a lightly oiled lint free white cloth
The most important part of liner installation is that the liner bores should be _________ same as integral cylinder for maximum diameter, out of round and taper
Measured
You should put a bead of high temperature______________under the top liner flange in order to ensure a leak proof seal
Room temperature vulcanizing (RTV) sealant
Before cleaning a crankshaft______
Remove the oil gallery plugs and reinstall them upon completion
Before storing the Crack apply a _________ and stand the crank on its end for larger and longer cranks store them_____________
Corrosion inhibitor or grease on the crank
Laying flat in a crate but supported by V blocks on the main bearings
_______ are sometimes referred to as a balancers or harmonic balancers
Vibration dampeners
Vibration dampeners are sometimes referred to as balancers or
Harmonic balancers
The purpose of a vibration dampeners is to_____
Reduce crankshaft torsional vibration
Most bearings have ______________ that is compatible with the shaft and the operating conditions of the engine
A steel backing with a layer or several layers of material
Engine bearings are usually one of two types
Sleeve or shell
_______ are one piece bearings that are often called bushings
Sleeve bearings
_____ are two piece bearings which allows for easier removal and replacement
She’ll type bearings
____ is the most accurate method of checking the bearing clearance but also the most time consuming
Measurements
______ measure the bearing clearance by using a dial indicator and hydraulic jack
Bearing lift check
Bearing lift checks measure the bearing clearance by using
Dial indicator and a hydraulic jack
The most common cause of bearing failure is ________
Lack of lubrication
The second most common cause of bearing failure is
Lubricant contamination
Lubricant contamination can be caused my
Dirt,water,antifreeze, fuel and acids formed from blowby or fuels
In the_____ method, the bolt length is measured before tightening
Bolt stretch (elongation)
Never use chrome faced rings in ______
Chrome plated liners
Any dots or lettering on the ring should be facing ____
Facing up
If the piston ring have a bevel inside it should face _____
Up
Most of the turbines are covered with insulation. Called _____ In order to retain heat and protect personnel
Lagging
Turbones are equipped with an emergency._____ to Shut off the steam in the event of_____
Trip mechanism
Overspeed
If a fluid either liquid or gas flowing through a tube Rachel’s a constriction or narrowing of the tube. The velocity of fluid flowing through the constriction increases and pressure decreases. Also, when the fluid leaves the construction, the velocity decreases and the pressure increases. This is called ______
Bernoullis principle
2 different turbone blades are.
reaction blades
Impulse blades
___ Blades are not symmetrical, and they look like an air foil.(wing)
Reaction blades
When the steam is released against the turbine blades, the total energy available from the steam is due to it’s heat, weight, pressure and velocity, this is called the.
Enthalpy of the steam
_____ Are arranged to direct the expanding steam toward the blades at the best angle Is it possible to harness the steams energy
Nozzles
______ Harness the steam’s energy by changing its direction. they are symmetrical and parallel to the shaft’s axis arranged around circumference of the wheel.
Impulse blades
_________ Is the removal of steam From the Turbine through the casing at various points. Steam is extracted at 1 or more points depending on the pressure level required.
Extraction
Condensing turbines exhaust steam to a _______
Condenser
The _____ is a heat exchanger that turns the steam back into hot water
Condenser
________ Steam turbines are more efficient than non condensing turbines due to less backpressure and recycled condensate
Condensing
The _________ Is mounted to the top of the turbine casing expose to the internal steam pressure? It is a warning device which indicates if the turbine casing has excess pressure. This device is only found on small impulse turbines.
Sentinel valve
_____ Consist of a set of knife edged fitting close to a journal like section of shaft.
Annulus seals
During normal operation a Spring holds the tripping leaver in position when the turbine speed increases to the trip setting usually _____ of operating speed
110%-115%
Small generators are_____ larger Generators are cooled with.
Air cooled
Hydrogen
The turbine can be shut down dismantled and the deposits Removed by manual buffering, scraping or blasting them with ____
Walnut shells or rice or high pressure dry ice
The acceptable range for oil discocity entering the bearing occurs when the oil temperature is between_________ And exit the bearing at about _______
105F-140F
130F-160F
The diaphrams are lowered into place and checked for their proper location of fit. They need to be secure in the housing and have the specified clearance. Above, Below and on each side of the road, if there is any rubbing on the rotor damage occurs immediately. A _____ can be used to determine clearance
Laser unit, piano wier,or dummy shaft
When all internal parts of the turbine lower casing are installed at a line, the final seal clearance to rotor location can be checked one method for checking rotor. 2 labyrinth seal clearance is by._______ using
Lead wier
The foundation of the turbine should be isolated from the other building floors, it should be at least.______
2.5 times the mass of All the turbone assembly so that it does not move and helps dampen vibrations from the machine.
_________ is when some of the exhaust heat is used to heat the air of combustion
Regeneration
________ is when exhaust heat is used to generate steam for power generation of other plant processes
Cogeneration
_________ is to improve the thermal efficiency of the gas turbine by using the exhaust heat (wast) to assist in the heating and expansion of the gases before the turbine
Regeneration
There is no reciprocation motion in the ___________
Gas turbine
There is no reciprocating motion in the gas turbine this reduces_______
Wear and vibration
Gas turbine can be started very _______ with no harmful effects to the engine and can be shut down in a reasonably short time
Quickly
_________ is air that enters the combustion liner (flame tube) to be mixed with fuel and burnt
Primary air
_______ is air that has no part in the combustion process
Secondary air
_______ connects the combustion chamber to the turbine and is a duct or passage long enough to mack sure the hot air is thoroughly mixed so there are no remaining hot gas pockets
Transition piece
The _____ type chamber is most often used on engines with centrifugal compressors
Can
______ are used with axial flow compressors. They have one housing around the shaft and one undivided liner inside the housing
Annular type chambers
The _________ chamber is a combination of both can and annular types. They are used with axial flow compressors
Can annular
The gas turbine must be rotated to about __________ of its maximum speed before the fule is turned on
20% to 30%
The __________ purpose is to control the turbines speed automatically under varying loads
Governor control
The _______ provides automatic registration of fule and compressor vanes for both starting and normal operation of the gas turbine
Governor control
The Highest temperature on the unit is found at the point where the heated air leaves the ______
combustion chamber
Defective fuel control ignition is the usual reason for Failure to start. Most engines have ______ igniters for ignition even though there may be a greater number of combustion chamber
1 or 2
The octane rating refers to the ability of the fuel to
Resist ignition due to compression
The gasoline fuel system uses a liquid fuel that must be _____ with air before it enters the engine cylinders
Metered and atomized and mixed
A major component in the system is the converter/regulator also called a
Vaporizer
