t_06_sgcie_energy audits.pdf
TRANSCRIPT
Energy Management : 2012/2013
Energy Efficiency in Industry and Energy audits
Prof. Paulo Ferrão
Energy Management
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SGCIE
Sistema de Gestão dos Consumos Intensivos de Energia,
Management System of Intensive Energy Consumption
The PT National Strategy for Energy, by the Decree-Law n. º
71/2008 of 15 April, regulates SGCIE.
SGCIE é uma das medidas constantes do PNAEE – Plano
Nacional de Acção em Eficiência Energética.
SGCIE is a measure included in the PNAEE - National Action Plan
for Energy Efficiency.
Energy Management
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SGCIE
The Rationalization Plan of Energy Consumption
(PREn) is developed based on the reports of mandatory
energy audits and shall provide for the implementation,
in the first three years, all identified measures with a
payback period of the investment (PRI) or less five
years in the case of facilities with power consumption
less than 1000 toe / year, or a PRI less than or equal to
three years for all other installations.
The PREn must also establish targets for energy and
carbon intensities and Specific Energy Consumption,
where applicable, based on measures provided in the
preceding paragraph, taking into account the following
indicators:
Energy Management
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SGCIE
1. Energy intensity, measured by the ratio between the total
energy consumption (considering only 50% of the energy
derived from endogenous waste and other renewable
fuels) and Gross Value Added (GVA) of business
activities directly linked to these sites;
2. Carbonic intensity, measured by the ratio between the
amount of emissions of greenhouse gases resulting from
the use of various forms of energy in the production
process and its total energy consumption;
3. Specific Energy Consumption, measured by the ratio
between the total energy consumption (considering only
50% of the energy derived from endogenous waste and
other renewable fuels) and the volume of production..
Energy Management
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SGCIE
The goals referred to in the preceding paragraph are subject
to the following values:
a) At a minimum, an improvement of 6% of the indicators
referred to in 1 and 3 above, in six years, in the case of
facilities with energy-intensive less than 1000 toe / year,
or 4% improvement in eight years for other facilities;
b) At a minimum, the maintenance of the historical values of
carbon intensity.
Energy Management
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SGCIE
Energy Management
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SGCIE
Síntese d aplicação para instalações com consumos de energia iguais ou superiores a 500 tep/ano
Energy Management
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SGCIE
Energy Management
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Forma de energia E.Eléctrica Propano
Unidade fisica MWh Ton
Gcal/unid. fisica 0.86 11.39
GJ/unid. fisica 3.60 46.30
Tep/unid. fisica 0.29 1.14
Mês E.Eléctrica Propano E.Eléctrica Propano
MWh Ton MWh Ton
Jan 266.5 176.3 374.0 150.3
Fev 285.3 152.6 435.7 171.6
Mar 270.8 169.1 397.3 194.3
Abr 385.4 165.2 410.0 123.6
Mai 322.8 158.7 416.7 180.2
Jun 368.6 157.9 468.8 185.7
Jul 367.0 151.1 464.1 194.1
Ago 336.1 115.2 292.0 156.9
Set 315.4 189.0 494.1 187.9
Out 410.5 188.7 398.8 199.1
Nov 398.7 196.6 493.4 209.2
Dez 431.2 162.8 422.8 158.3
Total 4,158.4 1,983.1 5,067.8 2,111.3
Média 346.5 165.3 422.3 175.9
1998 1999Mês 1998 1999
(fx) (fx)
Jan 33,324 56,894
Fev 37,658 51,774
Mar 40,846 58,383
Abr 35,727 43,010
Mai 41,889 45,421
Jun 45,167 48,938
Jul 45,463 52,463
Ago 36,083 35,180
Set 63,351 51,809
Out 60,443 48,316
Nov 67,612 51,692
Dez 53,611 30,666
Total 561,174 574,546
Média 46,765 47,879
Energy Management
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0
100
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700
0 10000 20000 30000 40000 50000 60000 70000
Produção Mensal
Factura Especifica ($/(fx))
Energy Management
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y = 0.0025x + 303.13
R2 = 0.1322
0
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0 10000 20000 30000 40000 50000 60000 70000
Produção Mensal
En
erg
ia E
léc
tric
a (
MW
h)
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0
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0 10000 20000 30000 40000 50000 60000 70000
ProduçãoMensal
Co
nsu
mo
Esp
ecíf
ico
Elé
ctr
ico
(kW
h/T
on
)
Energy Management
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0
1
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4
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7
0 10000 20000 30000 40000 50000 60000 70000
Produção Mensal
Consumo especifico de Propano (kgep/(fx))
Energy Management
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y = 0.0023x + 214.46
R2 = 0.2301
0
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0 10,000 20,000 30,000 40,000 50,000 60,000 70,000
Produção Mensal
En
erg
ia P
rim
ári
a (
Te
p/m
ês
)
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0
2
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0 10,000 20,000 30,000 40,000 50,000 60,000 70,000
Produção Mensal
Consumo especifico de Energia Primaria (kgep/(fx))
Energy Management
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EQUIPMENT
Energy Management
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Physical entities
• Electricity
• Mass flow
• Temperature
• Humidity
• Flue gases composition
• Luminance
• Total dissolved solids
Produtiva
Equipment
• Electrical analyzer
• Anemometer (turbine, Pitot)
• Thermometer
• Humidity meter
• O2, CO2, CO analyzer
• Luximeter
• TDS meter
Energy Management
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Energy Management
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0
50
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450
0:00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00
Potê
nci
a (
kW
)
Potência Média Potência Instantânea
Sábado Domingo6ª feira5ª feira4ª feira
Energy Management
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0
5
10
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45
50
12:00 15:00 18:00 21:00 0:00 3:00 6:00 9:00 12:00
Potê
nci
a (
kW
)
P. Média P. Instantânea
Medições no compressor 793
Energy Management
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Energy balances in energy audits
The energy balance in EAs differs from current
thermodinamic energy balances because some
unknowns are obtained by measurements.
Unknowns obtained from measurements have an error
of measurement
As a consequence, calculated unknowns do also show
errors.
Energy Management
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Energy balances in energy audits
The energy balance in EAs differs from current
thermodinamic energy balances because some
unknowns are obtained by measurements.
Unknowns obtained from measurements have an error
of measurement
As a consequence, calculated unknowns do also show
errors.
Energy Management
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Energy audit objectives:
1 - Energy accountancy (data)
2 - Energy consumption (measurements)
Direct measurement
Energy balance (equation + measures)
3 - Energy savings
Energy Management
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Energy balances in energy audits
The energy balance in EAs differs from current
thermodinamic energy balances because some
unknowns are obtained by measurements.
Unknowns obtained from measurements have an error
of measurement
As a consequence, calculated unknowns do also show
errors.
Energy Management
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Problems in energy balances
The number of equations frequently differs
from the number of unknowns
N. equations > N. unknows
• Not consider a measurement (a measurement
results in an equation)
• Create a chance to validate equations
N. equations < N. Unknows
• Requires estimatives
Energy Management
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Electrical
resistance
Wall
Losses
3
2 1
Qelec
Example: Industrial heat generator
Energy Management
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Equations and unknowns:
Mass and energy balance:
LossHTCmQTCmTCm
mmm
ppp .332211
321
Unknowns - measurements:
Good confidence: Q, T1, T2, T3
Less confidence: m1, m2
No confidence: m3, Heat loss
Energy Management
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Case 1: Equilibrium
2 Equations = 2 Unknowns
Measurements accepted:
Q, T1, T2, T3, m1, m2
Unknowns obtained by 2 eq. System:
m3, Heat loss
Energy Management
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Case 2: Less unknowns
2 Equations = 1 Unknown
Measurements accepted:
Q, T1, T2, T3, m1, m2, m3
Unknown obtained by resolution:
Heat loss
Allows to create an error type unknown:
Error of m3
Energy Management
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Case 3: Less equations
2 Equations = 3 Unknowns
Measurements accepted:
Q, T1, T2, T3, m1
Unknowns obtained by resolution:
m2, m3, Loss
Requires more measurements (and more
equations, specific humidity):
Water balance: Or assume a value for a unknown (!?)
332211 wmwmwm
Energy Management
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Frontier definition
Characterization of mass and energy flows
Equations identification
Definition of measurement plan
Equipment selection
Measurements
Validation
Produtiva
Energy balance sequence:
Energy Management
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COMPRESSED AIR
ANALYSIS
Atlas Copco
Energy Management
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2
1
vdPw
Physics of compression
1
1
1
21
P
PTmC
W
p
Energy Management
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Electrical measurements
Example
0
50
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250
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41
Tempo ([s]
Po
tên
cia
elé
ctr
ica [
kW
]
Funcionamento em carga Funcionamento em vazio
t1 t2 t3
1
1
1
21
P
PTmCp
Energy Management
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Combustion air
Natural gas
Flue gases
Water
Steam
Purge
Heat losses
Example 1: Boiler
Frontier anf flows
CSC
Energy Management
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DIRECT METHOD
Requires steam and combustible flow meters (feed water
meter is common)
HV
hhmsteam
Lmη
comb
waterfeedsteamboiler
Equations and measurements
Required data
Energy Management
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LOSSES METHOD (empiric)
1%)( Unburned
1%)( purging Steam
3%)( Walls
steam
gasesdry 10%)( gases Flue
L
Losses 100%ηBoiler
osses
Energy Management
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LOSSES BY THE WALLS
Where nominal losses depends on the boiler size, typically 1,5%.
Functioning factor: by stack temperature
factor FuncioningL nominal - walls
wallsLosses
osses
100
120
140
160
180
200
220
240
22-5-07 0:00 22-5-07 1:00 22-5-07 2:00 22-5-07 3:00 22-5-07 4:00 22-5-07 5:00 22-5-07 6:00 22-5-07 7:00
Te
mp
era
tura
[ºC
]
Energy Management
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Example 2: Aluminum furnace
Aluminum
Air
Comb. air
Melted aluminum
Gases
Propane
Is known the following data:
- Aluminum: flow and temp
- Air: temperature
- Combustion air: flow and temp
- Gases: temp, % O2
- Surfaces: temp, area
- Fan: electrical power
Energy Management
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Example 2: Aluminum furnace
Air
Aluminum Comb. air
Melted aluminum
Gases
Heat losses
Propane
Frontier and flows
Energy Management
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Example 2: Aluminum furnace
Equations
gases fluelossesheat aluminumventilatorpropane
gases fluein oxygen propanefor oxygen airin oxygen air combin oxygen
out aluminumin aluminum
gases flueairpropaneair comb
QQQWQ (4)
mmmm (3)
mm (2)
mmmm (1)
Air
Aluminum Comb. air
Melted aluminum
Gases
Heat losses
Propane
Energy Management
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Example 2: Aluminum furnace
Equations
gases fluelossesheat aluminumventilatorpropane
gases fluein oxygen propanefor oxygen airin oxygen air combin oxygen
out aluminumin aluminum
gases flueairpropaneair comb
QQQWQ (4)
mmmm (3)
mm (2)
mmmm (1)