Transcript KRISS NG Volume correction- Park

Gas Billing
2009. 12.
KRISS
Kyung-Am Park
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KRISS Fluid Flow Group
 High pressure gas flow
Lower than 10,000 m3/h, 0.18% -- 0.16%
10,000 m3/h ~ ??, limit criteria U < 0.2%
Build-up with sonic nozzles
 Oil flow
Spindle oil system is ready for (bilateral) KC
Light oil system maybe ready for KC next year
 Wind velocity measurement
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Gas selling unit
 Korea Gas Company
32 domestic gas dealers
0 C, 1.013 bar
Consumers
Measuring condition/conversion
 Gas flow measurement at measuring condition P, T
(m3/h)
 Volume conversion from measuring condition to reference condition
Volume corrector, Volume correction factor
 Conversion to Energy ----- billing maybe from 2011
 Constant CV – Volume selling ~ Energy selling
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NG volume correction factor for
domestic user
 Volume correction equation factor K
-Compressibility factor ~ 1
x
K 
Q
0
( Patm  Pgas )
1013.25
273.15
dt
(273.15  Tgas )
x
 Qdt
0
Q  flowrate(m3 / h)
Patm  Atmospheric Pressure
Tgas  GasTemperature
Pgas  GasPressure
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Gas flow pattern
 Real time pattern
- 2002 ~ 2007 year (average of 5 year)
(Total gas supply per hour) – (Total gas supply a
day)*(Industry supply ratio)/24
- assume “Gas flow of industrial use is constant”
 “Q” is obtained
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Gas pressure
 Measured average gas pressure: 22.46 mbar
 Atmospheric pressure: use average value of 10 years
obtained metrological observatory (every 3 hours) – 22
places
 Attitude correction
 City hall attitude is used
 Weighted average of apartment and house – 10.5 m
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Gas temperature
 Gas temperature in outside gas meter
- Atmospheric temperature: use average value of 10 years obtained
metrological observatory (every 1 hours) – 22 places
 Gas temperature in indoor gas meter in apartment
- Length of gas pipe line in indoor
- Gas flow rate
- Indoor air temperature : 8000 temperature sensors for 3 years
(Gas T.) = (Indoor air T.) – (ratio of T obtained be Exp.)*{(Indoor air
T.)– (Ambient T.)}
 Weighted average gas T. is obtained.
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Volume correction factor in Seoul
M /Y
Jan
Feb
M ar
A pr
M ay
June
July
A ug
S ep
O ct
N ov
D ec
averge
1999
1.0247
1.0201
0.9950
0.9690
0.9525
0.9310
0.9204
0.9202
0.9374
0.9717
0.9958
1.0230
0.9972
2000
1.0321
1.0270
0.9968
0.9731
0.9526
0.9289
0.9186
0.9217
0.9441
0.9705
1.0014
1.0206
1.0003
2001
1.0368
1.0245
0.9983
0.9712
0.9483
0.9323
0.9220
0.9205
0.9401
0.9637
0.9977
1.0280
1.0011
2002
1.0197
1.0134
0.9916
0.9695
0.9520
0.9329
0.9215
0.9266
0.9430
0.9761
1.0074
1.0196
0.9963
2003
1.0316
1.0133
0.9993
0.9708
0.9487
0.9339
0.9269
0.9274
0.9437
0.9721
0.9917
1.0209
0.9974
2004
1.0285
1.0127
0.9994
0.9706
0.9509
0.9324
0.9253
0.9206
0.9422
0.9707
0.9928
1.0183
0.9963
2005
1.0304
1.0299
1.0055
0.9703
0.9518
0.9305
0.9231
0.9245
0.9431
0.9716
0.9930
1.0368
1.0032
2006
1.0254
1.0253
0.9991
0.9719
0.9511
0.9339
0.9287
0.9183
0.9431
0.9609
0.9924
1.0206
0.9977
2007
1.0242
1.0080
0.9975
0.9776
0.9481
0.9312
0.9242
0.9209
0.9410
0.9697
1.0013
1.0151
0.9953
2008
1.0309
1.0292
0.9936
0.9689
0.9518
0.9365
0.9240
0.9224
0.9399
0.9659
0.9971
1.0169
0.9985
average
1.0284
1.0203
0.9976
0.9713
0.9508
0.9323
0.9235
0.9223
0.9418
0.9693
0.9971
1.0220
0.9983
Correction factor 0.9983 is used in Seoul area for 1 year from Jan. to Dec. 2009
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Calorific value factor
 Volume was unit of gas sale
 Try to change from Volume to Energy
 Natural gas supplied from 3 imported spots
 CV of natural gas may be different even in the supply area
of one domestic gas dealer
 Now, need CV factor : BTU factor
- How to divide NG supply area
- what is acceptable CV difference ??
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Using different natural gas??
 Consider billing
 Gas burners - efficiency, CO, NOx …
Gas turbine
NGV
Flame temperature ……
 Energy flow – Calorific value * gas flow rage
p
densiity0.5
CV
WobbeN 
SpecificGavity 0.5
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Comparison of interchangeability
suggestion - 1
14.0
Yellow tipping
Incomplete Combustion
Calorific value
3
kWh/m
13.5
13.0
12.5
Constant
Wobbe number:
15.9 kWh/m3
12.0
05', 06' µµÀÔ LNG
Yellow tipping °¡½º
Lifting °¡½º
±âÁØ°¡½º
11.5
11.0
Constant
Wobbe number:
14.0 kWh/m3
10.5
Lifting
10.0
0.45
0.50
0.55
0.60
0.65
0.70
0.75
3 ¾È
2 ¾È
1 ¾È
µ¿ÇØ°¡½º
·¯½Ã¾Æ(À¯·´°ø±Þ)
0.80
0.85
Specific Gravity
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Comparison of interchangeability
suggestion - 2
WobbeN 
CV
SpecificGavity 0.5
05', 06' µµÀÔ LNG
1 ¾È
2 ¾È
3 ¾È
µ¿ÇØ°¡½º
·¯½Ã¾Æ(À¯·´°ø±Þ)
Wobbe number
kWh/m3
16.5
K cal/m 3 kW h/m 3
10800
12.56
10500
12.21
10400
12.08
10100
11.75
16.0
15.5
15.0
14.5
14.0
10.5
11.0
11.5
12.0
12.5
Calorific value, kWh/m
13.0
13.5
3
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Gas Quality


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



Wobbe: 14.6 ~ 15.7 kWh/m3
CV: 11.0 ~ 12.5 kWh/m3
Methane: above 85%
H2S: below 6 mg/m3
Total sulfur: below 50 mg/m3
HC dew point: below -5 C
Water dew point : below -12 C at 7MPa
CO2: below 2.5 mole %
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