問題一覧
1
What is a non-condensing turbine?
Is a turbine that exhaust at atmospheric pressure or above
2
What is a condensing turbine?
Is a turbine that allows condensate to be reclaimed for use in the system
3
What are air ejectors?
Used to remove air and other non-condensable gases from condenser
4
How do you control the speed of a turbine?
By control valve
5
What is a tandem and compound turbine?
Tandem turbine- in which both axles are joined together Compound turbine- in which has two separate axles
6
What is an AC gear oil pump?
An electrically powered oil pump in the turbine lubricating system that serves as a back-up to the auxiliary pump
7
Why do you extract steam from a turbine?
To use for heating domestic water
8
What is certrifuge?
A device used to purify oil by spinning it to seperate impurities
9
What is control stage?
The first of a turbine, consisting of a nozzle block and a row of moving blading
10
What is control valves?
Steam valves leading to a turbine inlet that regulates the amount of steam the turbine receives
11
What is critical speed?
A turbine speed at which a rotor will vibrate excessively
12
What is fixed blading?
A turbine blading that is fixed to casing, consist of nozzle shaped blades that direct steam flow through the turbine
13
What is labrinyth?
A component of the gland seal system made of groove and ridges that form a tortuous path to restrict the flow of fluid such as air or steam
14
What is peening?
The process in which shrouding is attached to a row of moving blading by hammering tenons on the blades through holes in the shrouding to rivet the blading
15
What is counter flow turbine?
To balance the blades
16
How do you increase feed water pressure on a steam turbine pump?
By throttling on the Leslie feed water pressure regulator
17
What kind of energy does a turbine turn into?
From kinetic energy into mechanical energy
18
Types of blades that are in a turbine?
Stationary and rotating
19
A water seal is used to stop what on a turbine?
Leakage of air
20
After Steam leaves the turbine re-heater, it is routed to the:
Intermediate pressure turbine
21
Name the four sets of valves that control the flow of steam through the turbine:
1. Stop Valve 2. Control Valve 3. Reheat Stop Valve 4. Intercept Valve
22
In full are admission the stop valve are ____ and the control valves are ____?
Closed, fully open
23
During normal operation the intercept valves are _____?
Fully open
24
What supply the turbine lubricating oil during operation?
Main oil pump
25
____ is a comparison between the amount of energy supplied to the plant and the amount of energy leaving the plant
Plant efficiency
26
Where does the greatest amount of energy loss in the steam cycle occur?
Condense Cycle
27
In which cylinder of a three-cylinder turbine would the greatest amount of expansion be expected to occur?
Low pressure cylinder
28
What hardness can be removed by heating feed water?
Temporary
29
What hardness can be removed by chemicals?
Permanent
30
If the starter of the motor increases what happen to your NEMA number?
Decreases
31
Chemicals used to test water sample?
Reagents
32
What valve has press on top and bottom, has two seats, used for feed water?
Balance valve
33
What controls the starting and stopping of a hot water boiler?
Aqua-Stat
34
What three element feed water regulator senses?
Steam flow, feed water flow, water level
35
How many lbs of air need to burn 1 lb of of methane?
4 lbs
36
What are the steps of regeneration process of zeolite water softening?
Backwash, brine, rinse
37
Y configuration 208V all phases what voltage is phase to ground?
120V
38
Y Configuration 480V all phases what voltage is phase to ground?
277V
39
What is a shrouded ring?
1 metal attach to the outer edge of a turbine’s moving blading to dampen blade vibration.
40
What is turbine thrust?
A force created when moving steam strikes the blades in the turbine.
41
Where does the condensate from Hotwell go?
Back to the condensate tank
42
What is ramp rate?
The rate at which turbine metal temperature can be increased each hour during start up or decreased each hour during shutdown
43
What is analog signal?
Is a continuous signal of a continuous process
44
What is a digital signal?
Is a one time instantaneous signal.
45
What is set point?
Is the desired point in which a variable is controlled or maintained
46
What is a process variable?
Is the condition of what is being controlled
47
What is control loop?
Is a collection of control devices necessary for automatic control of a process
48
What is an input signal?
Is a signal going to a device
49
What is an output signal?
Is a signal leaving a device going to another device.
50
Types of coal?
Anthracite-Hard coal, high fixed carbon content. 14,000 BTU heating value Bituminous-Soft coal, high volatile content. 15,000 BTU heating value
51
What is mean by rank of coal?
Is the hardness f coal
52
What is meant by grades of coal?
Is the size, of the pieces of coal
53
Temp. of water leaving DA tank?
3 to 5 degrees of entering temp
54
Cylinder colors?
R11-orange, R12-white, R134-light sky blue, R22-light green, R404-orange, R407-chocolate, R410- rose, R500- yellow, R502-light purple, R507-light brown
55
Super critical boiler operates at?
3206 PSIA, 705 degrees- steam and water has the same density
56
What are the two producing elements of fuel?
Hydrogen and carbon
57
What are the three T’s of combustion?
Time, temperature and turbulence
58
What is installed of the discharge side of a reciprocating pump to reduce pulsation?
Air Chamber
59
What is acro name MATT mean?
Mixture, atomization, time, temperature
60
What is used to determine the moisture of steam?
Throttling calorimeter
61
A sudden increase in chimney temp with no increase in firing rate indicates?
Broken baffle
62
What is proximate analysis of coal?
Is the percentage of moisture, volatiles, fixed carbon and ash
63
What is ultimate analysis of coal?
Is the percentage of moisture, volatiles, fixed carbon, ash, sulfur and hydrogen
64
What is the purpose of grates when firing solid fuels?
It supports the burning fuel bed
65
How is grate surface expressed?
In square feet
66
What is bridged wall?
Is a firebrick wall built across the furnace to support the rear end of grates
67
Why would air be admitted over the fire?
It creates turbulence in the flue gases above the top of the fuel bed to help complete combustion
68
Why is coal ground to find powder?
So that it can be burned in suspension using a pulverized coal burner
69
What is a fluidized bed boiler?
Is a boiler in which fuel are burned in a bed of inert material, such as limestone and ash
70
What is a clinker?
Is a mass coal and ash that are fused together during burning
71
What are combustibles in the reuse?
Are unburned or partly burned pieces of coal in the ash coming off the grates.
72
What is banking a fire?
Is a process of slowing down the burning of coal or some other solid fuel
73
How are grades of fuel oil designated?
Grades of fuel oil are numbered No. 1 to No. 6
74
What are the heating value of fuel oil?
No. 2 = Amber, 141,000 btu/gal, 19,500 btu/lb, 0.8654 sp gr No. 4 = Black, 146,000 btu/gal, 19,100 btu/lb, 0.9279 sp gr No. 6 = Black, 150,000 btu/gal, 18,750 btu/lb, 0.9861 sp gr
75
How is viscosity of fuel oil measured?
Viscosity is the resistance to flow of liquid. Thick liquid has high viscosity while thin liquid has low viscosity.
76
Define flashpoint?
Is the temp in which vapor will flash when exposed to open flame
77
Define Firepoint
Is the temp in which vapor will ignite and burn continuously
78
Define pour point.
Is the temp in which a vapor will flow as a liquid
79
What is specific gravity?
Is the weight of a given volume of a material divided by the weight of an equal volume of water when both are measured at the same temp
80
What is API?
American Petroleum Institute- is used for the measurement of density for petroleum products or the petroleum scale
81
What are the three types of fuel oil burners?
Steam atomizing- use a steam to atomize air and fuel ratio Air atomizing- same as steam atomizing, It needs an air compressor to produce the air. Used on package boilers that uses #2 or #4 fuel oil. Pressure atomizing- uses high pressure from the oil pump to create atomization
82
What is a therm of natural gas?
A therm is a unit of measure indicating 100,000 BTUs
83
Describe the operation of safety shut off valve ?
Open- admits fuel to the gas burner. Closed – stop gas flow to the burner.
84
Describe standing pilot?
Is lit always whether the burner is on or off
85
Describe intermittent pilot?
Is lit when the burner is on and off when the burner is off
86
Describe interrupted pilot?
Is lit when the burner comes on and turns off as soon as the burner is lit
87
What is the purpose of the flame scanner?
It senses pilot and main flame signal of flame safeguard to stop firing sequence if either of the two won’t come on
88
What is a rectifier?
Converts alternating current (AC) to direct current (DC)
89
types of flame scanners:
Infrared flame scanners= senses, light radiation, invisible to the naked eye. It uses lead sulfide cell to detect light. Ultra violet flame scanner= are optical devices that senses is light radiation. Uses to electros cathode and anode. Photo cell flame scanner= are optical devices that senses visible light from the burner. It uses cesium oxide. Flame rod sensors= are not optical in nature. They work in the principle of ionization.
90
What is a manual reset device?
Is a device that must be manually reset by the operator before the flame safeguard control will be able to restart the burner equipment.
91
What is turn down ratio of a modulating burner?
Is the ratio of the maximum firing rate and minimum firing rate of the burner
92
What is flashback?
Is a condition where the flame travels upwind and into the burner assembly.
93
What is excess air?
Is the amount of air added to the combustion process over and above that which is theoretically necessary.
94
Why should the measurement of flue gas as close as the flue gas as possible?
To minimize dilution of air leaking to the furnace mixing with the flue gas for more accurate reading.
95
What is NOx?
Is produced as a chemical reaction between nitrogen and oxygen at high temp.
96
What process do you use to control NOx?
SCR= selective catalytic reduction
97
Define particulate?
Is a fine ash particle from a burner that ultimately settle back to the earth.
98
Define Ringlemann chart
Is a comparison chart used to measure opacity
99
What is Pyrometer?
Is an instrument that measures above temp. range of a thermometer.
100
What effect is soot in a boiler?
Soot is a great insulator on tubes and heating services. 1/16”= increased fuel consumption over 5%. 1/8”= increased fuel consumption over 9%