Quiz
08 Vapor Cycles
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Questions in this quiz (108)
1[blank_start]External combustion[blank_end] principle implies a working medium interposed so as to transfer heat from the region of combustion to the heat engine.
- AExternal combustion
2Heat produced by combustion is transferred by the heater to the [blank_start]working medium[blank_end].
- Aworking medium
3The [blank_start]prime mover[blank_end] transform part of the heat energy carried by the working medium into mechanical work.
- Aprime mover
4The change of physical phase which has been so widely used is [blank_start]vaporization[blank_end] and [blank_start]condensation[blank_end].
- Avaporization
- Bcondensation
5The [blank_start]fluid[blank_end] is taken into the heater as a liquid under pressure and there vaporized by the heat energy.
- Afluid
6[blank_start]Vapor cycle[blank_end] is the thermodynamic state of the working medium as it circulates from heater to the prime mover and back again.
- AVapor cycle
7[blank_start]Engine cycle[blank_end] considers only the changes occurring within the engine.
- AEngine cycle
8A [blank_start]vapor cycle[blank_end] involves, in addition, all changes in the vapor state.
- Avapor cycle
9A [blank_start]heat balance[blank_end] is an accounting of all energy units involved in a system.
- Aheat balance
10A [blank_start]heat stream[blank_end] is often the best way to present a heat balance.
- Aheat stream
11The most used principle in heat balancing is the [blank_start]first[blank_end] law of thermodynamics.
- Afirst
12The performance of vapor cycle plants may be expressed by its [blank_start]over-all thermal efficiency[blank_end].
- Aover-all thermal efficiency
13Rankine’s modification of the [blank_start]Carnot cycle[blank_end] is the basis of the modern steam plant.
- ACarnot cycle
14Rankine’s modification of the Carnot cycle is the basis of the [blank_start]modern steam plant[blank_end].
- Amodern steam plant
15The [blank_start]reheating cycle[blank_end] is a logical outgrowth of the trend to higher pressures.
- Areheating cycle
16The [blank_start]reheat vapor cycle[blank_end] is designed to keep the steam dry throughout more of the expansion.
- Areheat vapor cycle
17[blank_start]Reheat[blank_end] is accomplished by removing steam from the prime mover before it reaches the state of saturation, resuperheating it, and readmitting to the prime mover.
- AReheat
18In a [blank_start]closed rankine vapor cycle[blank_end], the steam generator receives feedwater under pressure from a pump.
- Aclosed rankine vapor cycle
19In a [blank_start]closed rankine vapor cycle[blank_end], the prime mover obtains the working expansion.
- Aclosed rankine vapor cycle
20In a closed rankine vapor cycle, the [blank_start]prime mover[blank_end] obtains the working expansion.
- Aprime mover
21In a [blank_start]closed rankine vapor cycle[blank_end], the condenser reduce the exhaust steam to liquid.
- Aclosed rankine vapor cycle
22In a closed rankine vapor cycle, the [blank_start]condenser[blank_end] reduce the exhaust steam to liquid.
- Acondenser
23A closed cycle plant ordinarily contains auxiliary equipment added for [blank_start]economic[blank_end] reasons.
- Aeconomic
24A [blank_start]closed[blank_end] cycle plant ordinarily contains auxiliary equipment added for economic reasons.
- Aclosed
25The [blank_start]enthalpy[blank_end] entering the prime mover is nominally the same as that leaving the steam generator.
- Aenthalpy
26Expanded steam from the prime mover is condensed to a liquid at constant [blank_start]pressure[blank_end] and [blank_start]temperature[blank_end].
- Apressure
- Btemperature
27[blank_start]Steam rate[blank_end] is established by timed tests during which output power and steam consumption are both measured.
- ASteam rate
28Increasing the efficiency requires [blank_start]increase[blank_end] in boiler pressure, initial superheat, and condenser vacuum.
- Aincrease
29[blank_start]Regenerative cycle[blank_end] is more efficient than the rankine cycle at the same terminal steam conditions.
- ARegenerative cycle
30The principal feature of the [blank_start]regenerative[blank_end] cycle is a thermal regeneration of condensate into high temperature feedwater.
- Aregenerative
31In a [blank_start]regenerative[blank_end] cycle plant, the heaters are set as close to the turbine as the plant layout allows.
- Aregenerative
32The [blank_start]surge tank[blank_end] absorbs the irregularities of cycle flow.
- Asurge tank
33In a regenerative cycle plant, [blank_start]traps[blank_end] are float or bucket operated chambers which holds back the steam and let the condensate pass.
- Atraps
34[blank_start]Extraction[blank_end] cycle refers to any arrangement wherein steam is bled from turbine at one or more pressures for any purpose.
- AExtraction
35[blank_start]Regenerative[blank_end] cycle implies that the extracted steam is used for one purpose only which is the thermal regeneration of the condensate.
- ARegenerative
36In [blank_start]regenerative[blank_end] cycle, additional heaters can be used more advantageously with higher throttle pressures that with lower throttle pressures.
- Aregenerative
37The location of the turbine zones to which the heater should be connected to, depends upon the [blank_start]steam pressure[blank_end] at the turbine throttle.
- Asteam pressure
38To obtain the maximum efficiency of a regenerative cycle plant, it is desirable that the amount of bled steam from the turbine to each heater are as nearly [blank_start]equal[blank_end] as possible.
- Aequal
39The [blank_start]higher[blank_end] the boiler pressure or the [blank_start]lower[blank_end] the condenser pressure, more stages of regeneration will be justified.
- Ahigher
- Blower
40In regenerative turbines, expansion of steam within the turbine is [blank_start]not isentropic[blank_end].
- Anot isentropic
41In [blank_start]regenerative turbines[blank_end], expansion of steam within the turbine is not isentropic.
- Aregenerative turbines
42Extraction of steam at constant pressure requires an [blank_start]extraction valve gear[blank_end] to regulate the area through which steam flows.
- Aextraction valve gear
43In regenerative cycle plant, the heaters are usually [blank_start]shell-and-tube[blank_end] construction, with steam contained within the shell and water flowing through the tubes.
- Ashell-and-tube
44Surface heaters with [blank_start]desuperheat[blank_end] zones are justified if the extracted steam contains high superheat.
- Adesuperheat
45Surface heaters with desuperheat zones are justified if the extracted steam contains [blank_start]high superheat[blank_end].
- Ahigh superheat
46A [blank_start]regenerative heater[blank_end] resembles a small surface condenser.
- Aregenerative heater
47[blank_start]Heaters[blank_end] are located near the turbine to have little pressure drop to the heater.
- AHeaters
48Wasted heat is often recovered by passing the flow from the condenser hotwell through [blank_start]generator air coolers[blank_end] before reaching the first regenerative heater.
- Agenerator air coolers
49[blank_start]Evaporators[blank_end] using extracted steam for vaporizing raw water are included when distilled water is used for make-up feedwater.
- AEvaporators
50The [blank_start]deaerating heater tank[blank_end] acts as a partial surge tank.
- Adeaerating heater tank
51In a turbine, moisture in expanding steam is [blank_start]undesirable[blank_end].
- Aundesirable
52[blank_start]Thermal deaeration[blank_end] is the removal of dissolved gasses, especially oxygen.
- AThermal deaeration
53[blank_start]Deaerators[blank_end] degasify water.
- ADeaerators
54Deaerators [blank_start]degasify[blank_end] water.
- Adegasify
55The heat of the steam used for jets in the condenser air ejectors is salvaged in an [blank_start]ejector condenser[blank_end].
- Aejector condenser
56The [blank_start]jet steam[blank_end] in regenerative cycle plant is taken from the main steam supply via pressure-reducing valves.
- Ajet steam
57The jet steam in [blank_start]regenerative[blank_end] cycle plant is taken from the main steam supply via pressure-reducing valves.
- Aregenerative
58The jet steam in regenerative cycle plant is taken from the main steam supply via [blank_start]pressure-reducing valves[blank_end].
- Apressure-reducing valves
59In regenerative cycle, [blank_start]more[blank_end] stages of bleeding steam, increases the efficiency of the system.
- Amore
60An [blank_start]adiabatic working process[blank_end] implies that the mechanical energy produced is at the expense of the heat in the steam.
- Aadiabatic working process
61[blank_start]Resuperheating[blank_end] is a feature associated with high steam pressures where there is insufficiently high initial steam temperature to yield an expansion.
- AResuperheating
62The minimum practical limit of the final dryness factor when resuperheating is [blank_start]86%[blank_end].
- A86%
63The minimum exhaust pressure when resuperheating is [blank_start]38.1 mm Hg abs[blank_end].
- A38.1 mm Hg abs
64The purpose of [blank_start]reheating[blank_end] can be seen as utilizing higher initial thermal states.
- Areheating
65Reheat cycle gains an addition on [blank_start]4[blank_end]% to [blank_start]7[blank_end]% in thermal efficiency compared to that of nonreheat cycle.
- A4
- B7
66Reheat cycle is only economical when constructed as a boiler-turbine unit of approximately [blank_start]50,000 Kw[blank_end] capacity or more.
- A50,000 Kw
67Reheat cycle is only economical when constructed as a [blank_start]boiler-turbine[blank_end] unit of approximately 50,000 Kw capacity or more.
- Aboiler-turbine
68[blank_start]Reheat[blank_end] cycle is only economical when constructed as a boiler-turbine unit of approximately 50,000 Kw capacity or more.
- AReheat
69Any power plant of a type that would be using reheating would also employ [blank_start]feedwater[blank_end] heating to a high-temperature level.
- Afeedwater
70[blank_start]Reheat[blank_end] temperature when using live steam cannot be much higher than boiler saturation temperature.
- AReheat
71Reheat temperature when using live steam cannot be much higher than [blank_start]boiler saturation[blank_end] temperature.
- Aboiler saturation
72[blank_start]Live steam[blank_end] reheaters was once used in earlier reheat cycles.
- ALive steam
73It is assumed than reheating begins at the [blank_start]saturation line[blank_end].
- Asaturation line
74[blank_start]Superposing[blank_end] a high-pressure steam plant on an existing plant increases its capacity.
- ASuperposing
75Superposing a high-pressure steam plant on an existing plant [blank_start]increases[blank_end] its capacity.
- Aincreases
76Modernizing existing equipment [blank_start]increases[blank_end] capacity of an existing plant.
- Aincreases
77[blank_start]Superposition[blank_end] refers to the thermodynamic position of new equipment, rather than its physical location.
- ASuperposition
78The capacity of the superposed unit and the throttle pressures required are derived from a coordinated study of [blank_start]load growths[blank_end].
- Aload growths
79A [blank_start]balanced[blank_end] heat and power supply is generally economical.
- Abalanced
80To equalize short-time, out-of-step fluctuations of heat and power demands, a [blank_start]steam accumulator[blank_end] can be used.
- Asteam accumulator
81Even with expensive installations, no more than [blank_start]30[blank_end]% of the heat value of coal can be converted to useful mechanical work.
- A30
82At instances where heat and power needs do not coincide in variability, a portion of power may be generated by the [blank_start]industry[blank_end] in the course of producing its heat needs and the balance purchased from a [blank_start]utility[blank_end].
- Aindustry
- Butility
83The [blank_start]mercury steam[blank_end] is the only binary vapor cycle operated on a commercial scale at the present time.
- Amercury steam
84[blank_start]Mercury[blank_end] as a vapor cycle has low specific enthalpy.
- AMercury
85Mercury as a vapor cycle has low [blank_start]specific enthalpy[blank_end].
- Aspecific enthalpy
86Mercury as a vapor cycle has moderate [blank_start]vapor pressure[blank_end] at higher [blank_start]temperature[blank_end].
- Avapor pressure
- Btemperature
87[blank_start]High density[blank_end] is a desirable property in securing separation of vapor form liquid in the boiler.
- AHigh density
88[blank_start]Mercury systems[blank_end] have been built as superposed units on existing steam plants whose pressures were too high to warrant consideration of superposed steam cycles.
- AMercury systems
89[blank_start]Mercury[blank_end] can seep through joints or cracks that would be impervious to water of steam.
- AMercury
90A [blank_start]binary vapor cycle power plant[blank_end] requires more investment per kilowatt capacity than a steam power plant.
- Abinary vapor cycle power plant
91It is assumed in the analysis of binary vapor cycle that steam expands [blank_start]isentropically[blank_end] from a [blank_start]dry[blank_end] and [blank_start]saturated[blank_end] condition.
- Aisentropically
- Bdry
- Csaturated
92It is assumed in the analysis of binary vapor cycle that the boiling water and mercury is at the [blank_start]same[blank_end] temperature.
- Asame
93[blank_start]Turbines[blank_end] are most efficient in their use of steam when the normal inlet valves are fully open.
- ATurbines
94Turbines are most efficient in their use of steam when the [blank_start]normal inlet valves[blank_end] are fully open.
- Anormal inlet valves
95Turbines are most efficient in their use of steam when the normal inlet valves are [blank_start]fully open[blank_end].
- Afully open
96When operating at part load, the rate flows of the plant throughout the vapor cycle will [blank_start]decrease[blank_end].
- Adecrease
97At [blank_start]part load[blank_end] in a regenerative cycle, there is a general decrease of pressures and feedwater temperature.
- Apart load
98The most economical division of load between two producing units occurs when their incremental heat rates are [blank_start]equal[blank_end].
- Aequal
99For [blank_start]variable load[blank_end] analysis, the heat rate is more useful than thermal efficiency.
- Avariable load
100For variable load analysis, the heat rate is [blank_start]more[blank_end] useful than thermal efficiency.
- Amore
101A [blank_start]no-load input[blank_end] is required to satisfy friction and radiation losses.
- Ano-load input
102The increment heat rate vs output lad curve can be drawn by mathematical or graphical analysis of the [blank_start]input-output characteristic[blank_end].
- Ainput-output characteristic
103Increasing the maximum temperature at which heat is added, increases the [blank_start]thermal efficiency[blank_end] in any power cycle.
- Athermal efficiency
104The simple rankine cycle continues the [blank_start]condensation[blank_end] process until saturated liquid state is reached.
- Acondensation
105The simple rankine cycle continues the condensation process until [blank_start]saturated liquid state[blank_end] is reached.
- Asaturated liquid state
106[blank_start]Superheating[blank_end] has the added advantage of decreasing the moisture content of the steam at the turbine exit.
- ASuperheating
107Lowering the exhaust pressure or raising the boiler pressure [blank_start]increases[blank_end] the moisture content.
- Aincreases
108[blank_start]Cogeneration[blank_end] is the production of more than one useful form of energy from the same energy source.
- ACogeneration
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- Power Plant Quiz on 08 Vapor Cycles, created by Kyllie Kylle on 02/10/2016.
- Author
- Kyllie Kylle
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- English
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