Overview This workbook consist of two calculations: 1) Power calculation Simple compressor power sizing calculation based on rate and suction 2) Power forcast Production forecast validation (ie. compression forecast generated f Checks the power required for the forecast rate, suction & discharge achievable for the specified power & number of compression stages. Liability No warrantees are made with respect to the accuracy or applicability The onous is on the user to verfiy that any results obtained are cor Copyright This spreadsheet is the intellectual property of the author, Andrew You are free to use it and distribute it however, you may not make i without prior written consent and you must not remove or obscure any don't steal or take credit for my work). Contact email: for other tools visit: SIMPLE COMPRESSOR POWER CALCULATION - READ ME Includes number of stages required, turbine sizing (de-rating), fuel [email protected]www.firstprincipleseng.net
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OverviewThis workbook consist of two calculations:
1) Power calculationSimple compressor power sizing calculation based on rate and suction & discharge pressure.
2) Power forcastProduction forecast validation (ie. compression forecast generated from a simulation).Checks the power required for the forecast rate, suction & discharge pressure and calculates the suction pressureachievable for the specified power & number of compression stages.
LiabilityNo warrantees are made with respect to the accuracy or applicability of the calculations in this spreadsheet.The onous is on the user to verfiy that any results obtained are correct and appropriate for the work being carrying out.
CopyrightThis spreadsheet is the intellectual property of the author, Andrew Hooks.You are free to use it and distribute it however, you may not make it available for download from any websitewithout prior written consent and you must not remove or obscure any notices regarding authorship. (Basicallydon't steal or take credit for my work).
Contactemail:for other tools visit:
SIMPLE COMPRESSOR POWER CALCULATION - READ ME
Includes number of stages required, turbine sizing (de-rating), fuel gas and CO2 emissions estimate.
Simple compressor power sizing calculation based on rate and suction & discharge pressure.
Production forecast validation (ie. compression forecast generated from a simulation).Checks the power required for the forecast rate, suction & discharge pressure and calculates the suction pressure
No warrantees are made with respect to the accuracy or applicability of the calculations in this spreadsheet.The onous is on the user to verfiy that any results obtained are correct and appropriate for the work being carrying out.
You are free to use it and distribute it however, you may not make it available for download from any websitewithout prior written consent and you must not remove or obscure any notices regarding authorship. (Basically
Includes number of stages required, turbine sizing (de-rating), fuel gas and CO2 emissions estimate.
Notes
Fluid properties
Process Conditions
Psuct 10.00 bara 1000 kPa(A)Pdisch 150.0 bara 15000 kPa(A)Tsuct 35 'C 308 K
Note that energy is also expended, and CO2 emitted, during the production & transport of a fuel. If you are using this calculation as an indicator of environmental impact, or to examine ways of reducing carbon footprint, you may also want to consider the source of proposed fuels in the CO2 balance.
B101
Shaft power Also known as Process Power or Site Power
E103
Turbine de-rating factors Taken from GPSA charts
F103
Engine de-rating factors Taken from Campbell v2
F104
Supercharged or Turbocharged? A compressor is used to increase the pressure (density) of the air before it is injected into the cylinder. Only relevant for the combustion engine.
B109
Accessories eg. Lube pumps, cooling fans
E109
Accessories For centrifugal compressors accessories are usually powered from a separate power gen. turbine. This differs from gas engines which are often smaller units and designed to be self-contained.
B116
Driver power - gas engines When selecting a gas engine driver maximum rpm, piston speed and BMEP (theoretical average pressure needed in the power cylinder throughout the power stroke to develop the rated power) must also be considered (see advise Cambell vol2).
Fuel rate = Power/Efficiency/LHV Design margin is excluded from the energy demand
H128
LPG Based on 60% C3, 40% C4 Actual composition can vary (even up to 75% C3, 25% C4)
E131
CO2 emission: Work with kg/s rather than m3/s since the conversion from m3 to moles is different for a liquid than a gas & we want one consistent formula that applies to both.
ISO conditions 15 'C 101.325 kPa (abs) 0% humidity
I107
Engine rated conditions Rated conditions vary between manufacturers
I123
HHV Higher Heating Value (also known as GHV, Gross Heating Value) The total heat obtained from combustion of a specified amount of fuel and its stoichiometrically correct amount of air, both being at 60'F when combustion starts, and the combustion products being cooled to 60'F before heat release is measured (ie. latent heat of water vaporisation is included).
N123
LHV Lower Heating Value Higher (gross) heating value minus the latent heat of vapourisation of the water vapour formed by the combustion of the hydrogen in the fuel. Turbine/engine performance is usually calculated using LHV since the latent heating value of the water is not captured.
Diesel density: Back calculated to be consistent with HHV values available. (Diesel is a liquid therefore the molar volume conversion used for gases above).
Compression ratio & number of stages to achieve it
Compression ratio
Nr Stages
Co
mp
res
sio
n r
ati
o &
Nr
sta
ge
s
U144
Stage2: 'Stage 1' calculates head based on discharge pressure up to the maximum stage compression ratio. 'Stage 2' head is then calculated based on Stage 1 discharge pressure. No attempt is made at balancing the head between the stages. This is a simplification (optimal distribution would result in a slightly lower power requirement) but is justified given the low level of definition inherent in this level of analysis.
S145
zdisch If zdisch is calculated from the lookup table and interpolation is used to estimate z at the actual discharge temperature - ie. interpolation between the two lookup lines, z(T=Ts) and z(T=Td)
X145
zdisch If zdisch is calculated from the lookup table and interpolation is used to estimate z at the actual discharge temperature - ie. interpolation between the two lookup lines, z(T=Ts) and z(T=Td)
AC145
zdisch If zdisch is calculated from the lookup table and interpolation is used to estimate z at the actual discharge temperature - ie. interpolation between the two lookup lines, z(T=Ts) and z(T=Td)
O147
Nr stages Round up compression ratio to filter out small discrepancies in pressure (especially prior to first stage coming onstream when Ps should equal Pd)
Lookup tableUnit SI unitmm = 0.001 mcm = 0.01 mm = 1 mkm = 1000 min = 0.0254 mft = 0.3048 mmile = 1609.3 m
Area_smallLookup tableUnit SI unit
= 0.000001
= 0.000645
= 1
= 0.0929
Area_largeBase conversionshectare/km2 100 hct/km2 1 hectare is 100m x 100mft2/acre 43559.66 ft2/acre
Lookup tableUnit Metric Unit
= 1
= 0.6214
hectare = 0.01
acre = 0.0040468
mm2 m2
in2 m2
m2 m2
ft2 m2
km2 km2
mi2 km2
km2
km2
D68
feet/metre International foot is defined as 0.3048m. US Survey foot is defined as 1200/3937 = 0.30480061m but is only used in connection with surveys by the US Coast & Geodectic Survey (Wikipedia)
ForceBase conversionsForce = mass * accelerationDyn 1.00E-05 N
Lookup tableUnit SI unitN = 1 NmN = 0.001 Nkg(f) = 9.80665 Nlbl(f) = 4.44823 NDyn = 0.00001 N
bbl/m3
in3/US gallon in3/gallon
m3
cm3 m3
m3
m3 m3
in3 m3
ft3 m3
m3
m3
m3
PressureBase conversionsPressure is force per unit area
kPa/Atmosphere 101.325 kPa(A)/atm(A) Atmospheric pressure at sealevel in kPakPa/bar 100 kPa/barbara/Atmosphere 1.01325 bara/atm The atmospheric pressure in bar at sealevel is 1.01325 barbarg/Atmosphere 0 barg/atmpsia/Atmosphere 14.696 psia/atm(A) The atmospheric pressure in psi at sealevel is 14.696 psipsi/bar 14.504 psi/bar
Lookup table!!! Order is important - multiply first then add the constant !!!
X barg = X barg + atm P = Y bara; eg. 1barg + 1.013 = 2.013bara1 bar = 100kPa --> X barg = [100*(X barg + 1.013bar/atm)] kPa(A), or = [100*X + 101.325] kPa(A)X bara = (X - 1.013)barg * 100kPa/bar + 101.3kPa/atm = X*100kPa(A)
Converting to psia first would give the same result, ie.the following are equivalent:[X psig + (14.5*1.013=14.7)] psia * (1kPa / 14.5psi) = kPa(A)orX psig * (1/14.5=6.895) kPa(G) + 101.3 kPa/atm = kPa(A)
A Joule is defined as the work done, or energy expended, by a force of 1 Newton moving one metre. J = N/m = (kg.m/s2).m = kgm2/s2
B332
International Steam Table Calorie (1 calorie is the energy required to raise the temperature of 1 gram of water by 1degree Celsius. Definitions differ slightly depending on initial temperature.)
B333
ISO standard definition (1 BTU is the amount of energy required to raise the temperature of 1 pound of water one degree Fahrenheit. Definitions differ slightly depending on the initial temperature).
E344
Energy rate: Sometimes used to describe flow rate therefore tabled separately from power
X barg = X barg + atm P = Y bara; eg. 1barg + 1.013 = 2.013bara1 bar = 100kPa --> X barg = [100*(X barg + 1.013bar/atm)] kPa(A), or = [100*X + 101.325] kPa(A)X bara = (X - 1.013)barg * 100kPa/bar + 101.3kPa/atm = X*100kPa(A)
Converting to psia first would give the same result, ie.the following are equivalent:[X psig + (14.5*1.013=14.7)] psia * (1kPa / 14.5psi) = kPa(A)orX psig * (1/14.5=6.895) kPa(G) + 101.3 kPa/atm = kPa(A)
(Water has viscosity of ca. 1cP at 20'C (1.002))
Kinematic viscosity = Dynamic viscosity / Density for a Newtonian fluid