A Few Examples The Wobbe Index of a gas with a specific gravity is 0.6 and a BTU/cubic foot heating value of 1000 is as follows: Wobbe Index = 1000 / √0.6 = 1291 A gas with a specific gravity of 0.6 and a BTU/cubic foot of 1050 is well within the typical range men-tioned in the AGA bulletin: Search for other works by this author on: This Site. The natural gas market is evolving, and customers have greater optionality to source their natural gas, especially LNG. LinkedIn recommends the new browser from Microsoft. This index shows the relationship between heat value and the specific gravity of gas, as a flow of energy at constant pressure. endobj Operation of the gas turbine within its specified fuel limits: The upper and lower limits of the fuel range ahs to be verified and hence the fuel’s property has to be tracked. endobj b. Gas Turbine Gas Fuel Composition Performance Correction Using Wobbe Index Bryan Li, Bryan Li Gas Turbine Thermal Performance Engineer GE Energy Services, Schenectady, NY 12306. 3 0 obj Ø controlled gas heating as a retrofit Wobbe Index control system Ø manufacturers’ control system modification for automatic Wobbe Index compensation and the potential for applying solutions developed across the existing gas turbine fleet Ø application of H-Gas to L-Gas switching experience to range switching in nominally The Wobbe Index in the H-gas standard and how to include renewable gases in the gas quality standardisation – CEN presentation Madrid Forum, 5 + 6 June 2019 CEN SFG Pre-normative study of H-gas quality parameter The Modified Wobbe Index (MWI) is a calculated measurement of volumetric energy content of fuel and the 7HA.03 can accommodate a MWI range that is double that of the 7HA.02 gas turbine. Verified combustion technology makes the gas turbines compatible with fuels that have a broader range of Wobbe Index (WI) value. x��w|TUއP�� �(��ˊ�X^T�uQt]\wײ !�����*`���w�{OH! It gives an indication of whether a turbine or burner will be able to run on an alternative fuel source without tuning or physical modifications. Of greatest concern are gaseous fuels associated with oil recovery that contain significant levels of water, H2S, and CO2. <>/XObject<>/Font<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI]>>/MediaBox[0 0 960 540]/Contents 29 0 R/Group<>/Tabs/S/StructParents 0>> 28/09/2017 2 ... Gas turbines and gas engines are probably the Variation in the natural gas composition affects the calorific value of the gas which may lead to increased pollutant emission (e.g. x��V]OA}'��pgm��#1>�H5����ӇU$��.P��@���V�6�,�3眹�޳@����c`��pt܁�I���1.�� ��yҺڃ"i�{�F���a�Y̘�LE��{I�s҂�y`��o1���Ǯ`�R\UpzG��d` 5B����n'(�t��r�S��kΠV"��(Q�C�?Q�6��T�� ����:�j��F���1+F@�b��e��8�#� i�?U�r��]��'�p:�?T��VV/��{�K/i]��]W�4dzs��i1�S��OH�0����C� �gI��*��gz-5��5ٯ[��:^;J�%�f�#�3���L�"�K����S�@8F�[C�MSMQ�^!Ma\��/� ��H�y*�#^e7�x�Y�W>?����Q�b�m�;��-�AS�A(l�5��Ev?�?5!� 2 0 obj Usually narrower the fuel characteristics change lower will be emissions as well. �'�RI&}&m�L���͛̚z�{g~���%s�3��9��s�y������k-7 ����g��f>��� � �_ �8� | �/ @� �� q� � �_ �8� | �/ @� �� q� � �_ �8� | �/ @� �� q� ����p����. Monitoring and keeping a track of the WI of the fuel gas fed to gas turbines can ensure the operator that the machine is running within its design fuel limits. Special focus is given to the problem of determining the dew point of the potential fuel gas at various pressure levels. endobj endobj Though by definition WI has the dimensions as BTU/SCF, is customary to use it without units so as to distinguish it from the normal volumetric heating value of gas. 3. <>stream However, fuel borne contaminants can also cause engine degradation. The standard Scope of Supply of each LHV Wobbe Index Calorimetric System is typically composed by. The Mexican NOM uses the Wobbe Index to deal with gas interchangeability. Schülken, Hiltrud Gas turbine is then rotate and drive motor or compressor to generate power and head. F#�i�g�u ���? However, natural gas supply and transport utilities are keen to determine the so-called Wobbe index [1, 3, 4]. The key difference between Wobbe index and Calorific Value is that the Wobbe index indicates the interchangeability of fuel gases whereas the Calorific Value indicates the total amount of heat energy generated when we burn a unit mass of fuel.. endobj ?� Gas turbine fuel is controlled on a volumetric basis and performance problems can occur when the Wobbe Index fluctuates widely. 2. The Wobbe-index is introduced as an important gas quality criterion when interchanging gaseous fuels for engines. $��6BjT�0��^F�Կ�d�ʣ���9��^��{�%��6��V6A��Q�BS�� QT�SKI��@:�O�8��0A��pJ�}>ˋ�/)�4�� Wobbe index for common fuel gases - propane, butane, methane and more Sponsored Links The Wobbe Index indicates the interchange ability of a fuel gas and is the best indicator of similarity between natural gas and a specific propane-air mixture. 3 illustrates this concept). The gas turbine manufacturer will provide specific guidelines on acceptable Wobbe Index fluctuations. PubMed. Based on the typical requirements of domestic and industrial gas heating devices, a classification into certain groups is defined in the standards. The fleet of SGT6-5000F gas turbines operating worldwide demonstrates an excellent reliability of 99%. WI avoids the necessity of having to worry about the changing fuel gas composition rather with only the gas’s heating value and its specific gravity the control loop can be tuned to regulate the fuel valves for achieving higher efficiency of the machine in a safe manner. Changes in fuel gas composition appear not to induce noticeable changes in air to fuel ratio and combustion velocity when the Wobbe-index remains the same. Higher the WI higher will be the heating value of the gas that will flow through a hole (orifice) of a given size at a given amount of time. Turbine is then rotate and drive motor or compressor to generate heat energy catastrophic of! 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