SPECIAL PRINT PPCHEM SPECIAL PRINT The Journal of All Power & Plant Chemistry Areas Sampling, Monitoring, Analytics Effects of Steam Sample Degassing on CCGT Station Start-up Profile Peter J. Clark PowerPlant Chemistry 2010, 12(4), 246–251 ANALYTICAL INSTRUMENTS Conductivity monitor with pH value and alkalizing reagent concentration calculation AMI Deltacon DG Automatic and continuous measurement of total, cation and degassed cation conductivity. Re-boiler according to Larson-Lane (ASTM D4519-94). Swan Analytische Instrumente AG CH-8340 Hinwil ∙ www.swan.ch [email protected] Water Steam Cycles PPCHEM JOURNAL ▪ SPECIAL PRINT (2021) PPCHEM® Journal ▪ www.ppchem.com ▪ SPECIAL PRINT (2021) ▪ PowerPlant Chemistry 2010, 12(4

PPChem SPECIAL PRINT PPCHEM Effects of Steam Sample Degassing on CCGT Station ANALYTICS SAMPLING, MONITORING, Start-up Profile Effects of Steam Sample Degassing on CCGT Station Start-up Profile Peter J. Clark ABSTRACT Many power stations dose feedwater with oxygen scavengers such as carbohydrazide; these compounds remove the dissolved oxygen but release inorganic carbon dioxide into the water. The effect of carbon dioxide upon corrosion levels is a controversial subject and as such is not within the scope of the work discussed in this paper. The effect of carbon dioxide upon conductivity measurements...

SAMPLING,MONITORING, ANALYTICS There are different methods of degassing water (or condensed steam) samples; the most popular ones are predominantly heating and stripping (gas and membrane) [1]. Boiling was chosen for this investigation as it is a reliable, proven technology for this application. Membranes such as those used in total organic carbon monitoring technology do not provide such a simple, robust and cost effective analysis. South Humber Bank is a triple steam pressure plant producing - high pressure (HP) steam at 91.6 bar - intermediate pressure (IP) steam at 19.3 bar - low pressure...

PPChem PPCHEM SPECIAL PRINT Effects of Steam Sample Degassing on CCGT Station Start-up Profile ACE) conductivity returned to the baseline result after 15 minutes for a cold start and 5 minutes for a hot start. The reboiler has proven its high efficiency. PRIOR INVESTIGATIONS A similar experiment was conducted by Pedro Wuhrmann of Swan Analytical Instruments to prove the effects of using degassed cation (ACE) conductivity as compared to cation (ACE) conductivity as a method of monitoring startup water purity. The results from this investigation provide the ideal pattern that the results from the...

PPCHEM SPECIAL PRINT PPChem Effects of Steam Sample Degassing on CCGT Station Start-up Profile Time [h:min] Time taken for DGCC to show lower conductivity than aftercation techniques Time [h:min] 12:51:00, whereas the classic cation (ACE) conductivity measurement does not even show such low levels of conductivity. Furthermore, degassed cation (ACE) conductivity values show fewer fluctuations in the results than the cation (ACE) conductivity values do. Figure 4: GT21 – Difference between cation (ACE) and degassed cation (ACE) conductivity of the steam sample. steam turbine earlier; however, as...

PPCHEM PPChem SPECIAL PRINT Effects of Steam Sample Degassing on CCGT Station Start-up Profile This data was collected from Day 3 of the commissioning program for GT22 so the profile and results are more suitable for a warm start-up. It is observable that the levels of degassed cation conductivity reach a required steam purity at much earlier times than the classic cation (ACE) conductivity levels (Figure 5). Using this in conjunction with Figure 4 gives the time saved by the use of the degassing technique to be on average 1 hour after a gas turbine (GT) start. However, steam conditions are not...

PPChem PPCHEM SPECIAL PRINT Effects of Steam Sample Degassing on CCGT Station Start-up Profile analysis depends upon the type of turbine and differs between stations and load profiles, so this has not been discussed in this report. CONCLUSION The application of a degassed cation conductivity monitor allows an earlier start-up of the steam turbine. However, whilst the steam conditions are ready for steam turbine synchronization earlier, this doesn't mean the steam turbine can be started earlier; conversely, the gas turbine can be fired up later preserving its life and allowing trading for a shorter...

PPCHEM SPECIAL PRINT Imprint PPCHEM® journal ISSN 1438-5325 (Print) ISSN 2571-9475 (Online) Publisher: PPCHEM AG P.O. Box 433 8340 Hinwil Switzerland Phone: +41 44 940 23 00 E-mail: [email protected] Editor in Chief: T. Werder (Switzerland) [email protected] International Advisory Board: Professor A. Bursik (Germany) R. B. Dooley (UK) Structural Integrity Associates, Inc. M. Gruszkiewicz (USA) Oak Ridge National Laboratory Professor D. D. Macdonald (USA) U.C. Berkeley B. Stellwag (Germany) R. Svoboda (Switzerland) M. Rziha (Switzerland) PPCHEM AG F. U. Leidich (Germany) D. Addison (New Zealand)...