1. 1 Gas Billing 2009. 12. KRISS Kyung-Am Park

2. 2 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

3. 3 Gas selling unit  Korea Gas Company 32 domestic gas dealers Consumers  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 0 C, 1.013 bar Measuring condition/conversion

4. 4 NG volume correction factor for domestic user  Volume correction equation factor K -Compressibility factor ~ 1

5. 5 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

6. 6 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

7. 7 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.

8. 8 Volume correction factor in Seoul Correction factor 0.9983 is used in Seoul area for 1 year from Jan. to Dec. 2009

9. 9 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 ??

10. 10 Using different natural gas??  Consider billing  Gas burners - efficiency, CO, NOx … Gas turbine NGV Flame temperature ……  Energy flow – Calorific value * gas flow rage

11. 11 Comparison of interchangeability suggestion - 1

12. 12 Comparison of interchangeability suggestion - 2

13. 13 Gas Quality  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 %