NDLI: A Gas Turbine Innovative System for Managing Fuel With Different and Variable-Over-Time Wobbe Indexes

Content Provider	The American Society of Mechanical Engineers (ASME) Digital Collection
Author	Forte, Annalisa Asti, Antonio Bei, Simone Betti, Massimo D’ercole, Michele Paci, Mariateresa Tonno, Giovanni Jesse, F. Stewart
Copyright Year	2008
Abstract	Due to the substantial increase in sources of gas, natural gas interchangeability is a key subject in the industry today. The extensive pipeline network means that natural gas arriving at appliances, boilers, burners and power plant turbines could come from anywhere. Fuel compositions vary from one source to another. Moreover, most recently, Liquefied Natural Gas has emerged as a major source and the composition of gas derived from LNG substantially differs from the natural gas one. In Dry Low NOx (DLN) systems, those changes in fuel composition can cause dangerous increase in combustion dynamics and can also affect the NOx emissions of the machine. Therefore, in order to meet the growing market demand for gas turbine combustors able to tolerate significant alterations in fuel composition, a system capable of burning gases with differing and variable over time Wobbe Indexes was developed. This innovative system does not involve any combustion hardware modifications. It allows the use of a premixed combustion system that complies with emissions, reliability, and safety, even when burning a fuel that is distinctly different from the original design gas. In particular, the system was developed in order to meet the requirements of a customer for burning any continuously and slowly varying mixture of two fuel gases, whose Wobbe Indexes difference is up to 25%. Since the burner is designed for 100% of the gas with lower Wobbe Index, the gas that has a higher WI needs to be heated, in order to achieve a target Modified Wobbe Index; the same happens for any mixture of the two gases. The system is based on a closed loop control on the Modified Wobbe Index of the fuel. Two turbine control gas chromatographs, located upstream the combustor inlet, measure the gas characteristics (LHV, specific gravity and temperature) and calculates the MWI. If it is different from the target one, it is corrected by modifying the temperature set point of a heat exchanger. The hardware is completed with one more plant gas chromatograph, located upstream the heat exchanger, for evaluating the fast and complete switch from one gas to the other one. In addition to the normal operation, that is with the 100% Lower Wobbe Index gas (L) or 100% Higher Wobbe Index gas (H) or any continuously and slowly varying mixture of these two gases, the system allows both the black and the normal start, the complete switch back and forth between 100% L gas and 100% H gas and load sheds and rejection. Moreover the two gases can be burned in diffusion combustion mode, as available, without requiring any increase in temperature, with no limitation from firing to full load. The capability of the system to adjust to all of the previously described events, potentially dangerous and damaging for the Gas Turbine combustion system, makes it suitable for applications that burn different lots of gases coming from different LNG sources, since it allows the turbine to accommodate the differences in Wobbe Index, due to various gas lots on a pipe line.
Sponsorship	International Gas Turbine Institute
Starting Page	877
Ending Page	885
Page Count	9
File Format	PDF
ISBN	9780791843130
DOI	10.1115/GT2008-51189
e-ISBN	0791838242
Volume Number	Volume 3: Combustion, Fuels and Emissions, Parts A and B
Conference Proceedings	ASME Turbo Expo 2008: Power for Land, Sea, and Air
Language	English
Publisher Date	2008-06-09
Publisher Place	Berlin, Germany
Access Restriction	Subscribed
Subject Keyword	Fuel management Temperature Pipelines Switches Combustion Fuels Density Machinery Design Gas turbines Gaseous fuels Power stations Hardware Combustion systems Safety Turbines Firing Boilers Liquefied natural gas Heat exchangers Diffusion (physics) Stress Emissions Gases Gas chromatography Dynamics (mechanics) Nitrogen oxides Combustion chambers Reliability Natural gas
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in