POWER PLANT Flashcards
All the coal and partings lying between a roof and floor
Coalbed
A subdivision and (or) layer of a coal bed separated from other layers by partings
of non-coal rock.
Bench
A dense coal, usually black, sometimes dark brown, often with well-
defined bands of bright and dull material, used primarily as fuel in steam-electric power
generation, with substantial quantities also used for heat and power applications in
manufacturing and to make coke. Bituminous coal is the most abundant coal in active
U.S. mining regions. Its moisture content usually is less than 20 percent. The heat content
of bituminous coal ranges from 21 to 30 million Btu per ton on a moist, mineral-matter-
free basis. The heat content of bituminous coal consumed in the United States averages
24 million Btu per ton, on the as-received basis (i.e., containing both inherent moisture
and mineral matter).
Bituminous Coal
The fine screenings from crushed coke. Usually will pass through a 1/2-inch or 3/4-inch screen opening.
Breeze
It is most often used as a fuel source in the process of agglomerating iron ore.
Breeze
The amount of heat needed to raise the temperature of 1
pound of water by 1 degree fahrenheit. Is a convenient measure by which to compare the energy content of various fuels
Btu (British thermal unit)
A compact, tough variety of coal, originating from organic spore residues,
that is noncaking, contains a high percentage of volatile matter, ignites easily, and burns
with a luminous smoky flame.
Cannel Coal
Coal produced and consumed by the mine operator, a subsidiary, or parent
company (for example, steel companies and electric utilities).
Captive Coal
A colorless, odorless, incombustible gas formed during
combustion in fossil-fuel electric generation plants
Carbon Dioxide (CO2)
A readily combustible black or brownish-black rock whose composition, including
inherent moisture, consists of more than 50 percent by weight and more than 70 percent
by volume of carbonaceous material.
Coal
It is formed from plant remains that have been
compacted, hardened, chemically altered, and metamorphosed by heat and pressure over
geologic time
Coal
Natural condition of the environment at any given time.
Ambient
Water-bearing stratum of permeable sand, rock, or gravel.
Aquifer
Electricity-generating units that are operated to meet the constant or minimum load on the system. The cost of energy from such units is usually the lowest available to the system./
Baseload Plants
A geothermal electricity generating plant employing a closed-loop heat exchange system in which the heat of the geothermal fluid (the “primary fluid”) is transferred to a lower-boiling-point fluid (the “secondary” or “working” fluid), which is thereby vaporized and used to drive a turbine/generator set.
Binary-Cycle Plant
A geothermal solution containing appreciable amounts of sodium chloride or other salts.
Brine
Rocks of low permeability that overlie a geothermal reservoir.
Cap Rocks
A process that uses a stream of geothermal hot water or steam to perform successive tasks requiring lower and lower temperatures.
Cascading Heat
Water formed by condensation of steam.
Condensate
Equipment that condenses turbine exhaust steam into condensate.
Condenser
A structure in which heat is removed from hot condensate.
Cooling Tower
Earth’s outer layer of rock. Also called the lithosphere.
Crust
A type of direct use in which a utility system supplies multiple users with hot water or steam from a central plant or well field.
District Heating
Boring into the Earth to access geothermal resources, usually with oil and gas drilling equipment that has been modified to meet geothermal requirements.
Drilling
Very hot steam that doesn’t occur with liquid.
Dry Steam
The ratio of the useful energy output of a machine or other energy-converting plant to the energy input.
Efficiency
Rock fracturing, water injection, and water circulation technologies to sweep heat from the unproductive areas of existing geothermal fields or new fields lacking sufficient production capacity.
Enhanced Geothermal Systems
A fracture or fracture zone in the Earth’s crust along which slippage of adjacent Earth material has occurred at some time.
Fault
Steam produced when the pressure on a geothermal liquid is reduced. Also called flashing.
Flash Steam
A vent or hole in the Earth’s surface, usually in a volcanic region, from which steam, gaseous vapors, or hot gases issue.
Fumarole
Of or relating to the Earth’s interior heat.
Geothermal
The Earth’s interior heat made available to man by extracting it from hot water or rocks.
Geothermal Energy
The rate of temperature increase in the Earth as a function of depth. Temperature increases an average of 1° Fahrenheit for every 75 feet in descent.
Geothermal Gradient
Devices that take advantage of the relatively constant temperature of the Earth’s interior, using it as a source and sink of heat for both heating and cooling. When cooling, heat is extracted from the space and dissipated into the Earth; when heating, heat is extracted from the Earth and pumped into the space.
Geothermal Heat Pumps
A spring that shoots jets of hot water and steam into the air.
Geyser
A large geothermal steam field located north of San Francisco.
The Geysers
Subsurface geologic formations of abnormally high heat content that contain little or no water.
HDR (hot dry rock)
A device for transferring thermal energy from one fluid to another.
Heat Exchanger
Movement of heat from within the Earth to the surface, where it is dissipated into the atmosphere, surface water, and space by radiation.
Heat Flow
Underground systems of hot water and/or steam.
Hydrothermal Resource
The process of returning spent geothermal fluids to the subsurface. Sometimes referred to as reinjection.
Injection
Assessing the geologic, engineering, and physical properties and characteristics of geothermal reservoirs with instruments placed in the wellbore.
Well Logging
A geothermal reservoir system in which subsurface pressures are controlled by vapor rather than by liquid. Sometimes referred to as a dry-steam reservoir.
Vapor-Dominated
A bladed, rotating engine activated by the reaction or impulse, or both, of a directed current of fluid. In electric power applications, such as geothermal plants, the turbine is attached to and spins a generator to produce electricity.
Turbine
Structures and conductors that carry bulk supplies of electrical energy from power-generating units.
Transmission Line
The rate of increase or decrease in the Earth’s temperature relative to depth.
Thermal Gradient
Used to describe the amount of solid materials in water.
TDS (Total dissolved solids)
A sinking of an area of the Earth’s crust due to fluid withdrawal and pressure decline.
Subsidence
A measure of the quantity or concentration of dissolved salts in water.
Salinity
A natural underground container of liquids, such as water or steam (or, in the petroleum context, oil or gas).
Reservoir
The ratio of the aggregate volume of pore spaces in rock or soil to its total volume, usually stated as a percent.
Porosity
A theory of global-scale dynamics involving the movement of many rigid plates of the Earth’s crust. Tectonic activity is evident along the margins of the plates where buckling, grinding, faulting, and vulcanism occur as the plates are propelled by the forces of deep-seated mantle convection currents. Geothermal resources are often associated with tectonic activity, since it allows groundwater to come in contact with deep subsurface heat sources.
Plate Tectonics
The capacity of a substance (such as rock) to transmit a fluid. The degree of _______depends on the number, size, and shape of the pores and/or fractures in the rock and their interconnections. It is measured by the time it takes a fluid of standard viscosity to move a given distance. The unit of____ is the Darcy.
Permeability
Electricity generating plants that are operated to meet the peak or maximum load on the system. The cost of energy from such plants is usually higher than from baseload
Peaking Plants
The _______ is sometimes called the ripple effect because a single expenditure in an economy can have repercussions throughout the entire economy. The _______ is a measure of how much additional economic activity is generated from an initial
Multiplier Effect
The Earth’s inner layer of molten rock, lying beneath the Earth’s crust and above the Earth’s core of liquid iron and nickel.
Mantle
Molten rock within the Earth, from which igneous rock is formed by cooling.
Magma
The simultaneous demand of all customers required at any specified point in an electric power system.
Load
The energy represented by 1 kilowatt of power consumed for a period of 1 hour, equal to 3,413 Btus. Abbreviated kWh./ Load
Kilowatt-Hour
A region identified by the U.S. Geological Survey as containing geothermal resources.
KGRA. Known Geothermal Resource Area.
The amount of coal decomposed into solid coke and gaseous products by heating in a coke oven in a limited air supply or in the absence of air.
Coal Carbonized:
The classification of coals according to their degree of progressive alteration from lignite to anthracite. In the United States, the standard ranks of coal include lignite, subbituminous coal, bituminous coal, and anthracite and are based on fixed carbon, volatile matter, heating value, and agglomerating (or caking) properties.
Coal Rank:
The collection and proper storage and handling of a relatively small quantity of coal for laboratory analysis.
Coal Sampling
a sample taken at the exposed coal in a mine by cutting away any loose or weathered coal then collecting on a clean surface a sample of the coal seam by chopping out a channel of uniform width and depth;
Face Channel or Channel Sample
a channel or drill core sample taken to represent the entire geologic coalbed; it includes all partings and impurities that may exist in the coalbed.
Column Sample:
a face or channel sample taken of just that contiguous portion of a coalbed that is considered practical to mine, also known as a “bench;
Bench Sample:
