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Select a letter to view associated terms and definitions. |
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A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
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| - A - |
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| Absolute Humidity: |
Ratio of the mass of gases: water vapor to non-condensable gas. |
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| Adiabatic Process: |
A process where no Heat is transferred
across system boundaries.
For example: consider cool water and hot dry
air mixed together inside an insulated duct, with the duct walls set as the
boundaries of the system; the air and water temperature would come to thermal
equilibrium as they mix (some water would vaporize and the air would cool).
This process would be defined as adiabatic. |
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| Air Heater: |
A device used to transfer Heat
between air and another substance while keeping the two materials separated. |
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| - B - |
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| Boiler: |
A mechanical device that generates steam. This
is accomplished through the transfer of Heat Energy to water, changing
its Enthalpy and its physical state from liquid to vapor/gas. |
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| Boiler Feedwater: |
Boiler Feedwater is converted from Boiler
Makeup Water as it passes through the Deaerating Heater. The water is
broken up into fine droplets and heated (using steam) to produce a vapor inside
the Deaerating Heater and the dissolved gases are stripped away from the
water vapor as it condenses. |
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| Boiler Flue Gas: |
Exhaust generated from the combustion chamber
of a Boiler. This stream is commonly kept at an elevated Temperature
to avoid condensation in flue stack. |
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| Boiler Makeup Water: |
Raw water that has been filtered and
softened by exchanging multiple-charged cations with single-charged cations
(such as Ca++ or Fe++ with Na+).
For high pressure boilers (steam pressures above 300-psig), ion-exchange system
substitutes cations and anions with hydrogen ions (H+) or hydroxide
(OH-)ions. |
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| - C - |
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| Combustion: |
The exact amount of air containing enough oxygen
to combust fuel at 100% Combustion Efficiency. |
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| Combustion Efficiency: |
The measure of the oxidation of fuel.
The degree of completeness of oxidation. For example, when carbon
burns producing carbon dioxide it is fully oxidized and combustion efficiency is
100%. If no carbon is oxidized the efficiency is 0%. If only carbon
monoxide is produced then efficiency is 50%. |
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| Condensate Return: |
The amount of condensed steam returned from
use point and used as Boiler Feedwater. Boiler Makeup Water
is added to system to take place of any steam/condensate losses. |
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| Condensing Economizer: |
A heat exchanger that transfers heat
from a Boiler Flue Gas to Boiler Makeup Water. Two types:
Direct and Indirect Contact. |
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| Cost-Savings: |
Heat returned to the process must have
an economizing benefit that can be quantified and verifiable to be classed
as savings. Displacement of Virgin Energy is a straightforward method of claiming savings. |
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| - D - |
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| Deaerating Heater: |
Mechanical devices that liberate gases (air,
oxygen (O2), carbon dioxide (CO2)or other gases) from
Boiler Makeup Water; also referred to as Deaerators. |
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| Direct Contact Heat Transfer: |
A literal description of what happens when two
streams are mixed together to transfer Heat and then separated.
Direct Contact Heat Transfer requires mostly immiscible fluids
(e.g. – 2 phase gas-liquid mixture). Miscible fluids cannot be separated.
Minor portions of the two streams may be miscible and are transferred
with the Heat. |
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| - E - |
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| Economizer: |
A heat exchanger that transfers heat from a
Boiler Flue Gas to Boiler Feedwater. |
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| Energy: |
Energy is the capacity to do Work.
Both Work and Heat have the unit of Work
[(lb-ft/sec2)*ft]. |
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| Engine: |
An Engine is a machine, which converts various
from of Energy to mechanical Work. |
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| Enthalpy: |
The thermodynamic property used to represent sum
of Energy contained within a substance including: internal and potential
Energy. |
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| Excess Air: |
Any air included in the combustion process in
excess of the Combustion Air. |
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| - F - |
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| Force: |
A pull or a push. The term implies that
resistance to movement is being encountered [engineering unit: lb; pound = the
force which will impart an acceleration of 32.174 ft per sec per sec to
a 1-lb mass]. |
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| - H - |
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| Heat: |
The form of Energy associated with movement
of molecular or smaller particles that flows by virtue of a Temperature
difference. Energy contained in one material can transfer to another
material through solids by conduction, fluids by convection, and voids by radiation.
Heat cannot completely convert to Work. |
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| Heat Capacity: |
The quantity of Heat required raising a
specific amount of material one degree of Temperature without a change of
phase, either at constant pressure or volume [engineering unit: ft2/sec
2-oF]. |
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| - L - |
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| Latent Heat of Vaporization: |
Heat added or removed to a material that
changes its phase: solid to liquid, liquid to gas and solid to gas, or the
reverse. |
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| - N - |
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| Non-Condensable: |
Gas that will not condense within the system
Temperature range. |
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| - P - |
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| Power: |
The time rate of doing Work [engineering unit:
lb-ft2/sec3]. |
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| Phase: |
The state of a material: solid, liquid or gas |
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| - R - |
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| Raw Water: |
Untreated water from a common supply. |
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| Recovered Heat: |
Waste Heat that is captured and returned to a system. |
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| Relative Humidity: |
The ratio of Absolute Humidity divided by
the saturated humidity at Temperature of gas. |
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| - S - |
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| Saturated Air: |
Describes state at which air containing water vapor
will not hold any more water vapor at a particular Temperature and pressure.
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| Sensible Heat: |
Heat added to a material raising its
Temperature. |
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| - T - |
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| Temperature: |
The measure of the relative internal Energy
of a material or system. A physical property, which determines the direction of
flow of Heat between materials in thermal contact; Heat flows from
the higher Temperature material to the lower Temperature material. |
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| - V - |
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| Virgin Energy: |
Energy that is metered as it is delivered to a
process (e.g. - natural gas or electric power). |
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| - W - |
Top of Page |
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| Waste Heat: |
Heat lost from a system. |
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| Water of Combustion: |
Water that is formed when a hydrocarbon fuel is
burned in air or oxygen; (CxHy)
+ (O2) -->
(CO2) + (H2O). |
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| Work: |
Work (W) is a form of Energy and is defined
as the product of a Force acting through a distance in the direction of
that Force [engineering unit: ft-lb]. Work can be totally converted to Heat. |
