Institut für Verbrennungskraftmaschinen Prof. Dr.-Ing. Peter Eilts. Workshop Metrology for LNG Methane Number

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1 Workshop Metrology for LNG Methane Number

2 Outline Knocking Methane Number Service Methane Number 1. Juni 2015 Benjamin Tilch Teamleiterrunde Folie 2

3 Outline Knocking Methane Number Service Methane Number 1. Juni 2015 Benjamin Tilch Teamleiterrunde Folie 3

4 Knocking Flame propagation with normal combustion 1. Juni 2015 Folie 4

5 Knocking Flame propagation with knocking combustion p me = 8,5 bar n = 2400 U/min = 18 KW vor OT Z 1. Juni 2015 Folie 5

6 Knocking Cylinder pressure with knocking combustion ca m/s Flame speed m/s 1. Juni 2015 Folie 6

7 Outline Knocking Methane Number Service Methane Number 1. Juni 2015 Folie 7

8 Methane Number Definition of the Methane Number The Methane Number (MN) of a gas is defined as the percentage of Methane in a mixture of Methane and Hydrogen which has the same knocking behaviour as the gas to be investigated in a defined test engine under defined operating conditions. It was developed by AVL in the late 1960s. 1. Juni 2015 Folie 8

9 Methane Number AVL and MWM correlation A correlation developed by AVL exists which allows to calculate the MN of a gas from its composition. In this correlation higher hydrocarbons (> C4) are only considered in a very simple manner. The AVL correlation has been further developed by MWM. Now higher hydrocarbons are considered in more detail. Further the influence on N 2 is treated differently. The MWM correlation has been developed on large lean-burn engines. It has not yet been tested on automotive engines operating stoichiometrically. Besides the AVL and MWM correlation there are further methods in the literature. 1. Juni 2015 Folie 9

10 Methane Number Measurement of the MN The MN can only be measured with the requipment used by AVL during the development of the method, just like the RON and MON can only be measured with a CFR engine. Unfortunately this equipment is not readily available. If a different engine or different operating conditions are employed the results are different. The result is called the Service Methane Number (SMN). 1. Juni 2015 Folie 10

11 Outline Knocking Methane Number Service Methane Number 1. Juni 2015 Folie 11

12 Service Methane Number Definition of the Service Methane Number The Service Methane Number (SMN) of a gas is defined as the percentage of Methane in a mixture of Methane and Hydrogen which has the same knocking behaviour as the gas to be investigated in an arbitrary engine under arbitrary operating conditions. The SMN shows the same tendencies as the MN, but different absolute values. Depending on the boundary conditions chosen the correlation between SMN and MN can be nearly linear. 1. Juni 2015 Folie 12

13 Service Methane Number SMN of NG-Propane-mixtures at different engine speeds Source: [1], Fig Juni 2015 Folie 13

14 Service Methane Number SMN of NG-Propane-mixtures at different engine speeds Source: [1], Fig Juni 2015 Folie 14

15 Service Methane Number Comparison of SMN on the CFR/RDH- and MWM-engine 1. Juni 2015 Folie 15 Source: [1], Fig. 5.15

16 Service Methane Number Service Methane Number of NG-Hydrogen-Propane mixtures 1. Juni 2015 Folie 16 Source: [1], Fig. 5.44

17 Service Methane Number Methane Number Source: [2] 1. Juni 2015 Folie 17

18 Service Methane Number Service Methane Number compared to Methane Number 1. Juni 2015 Folie 18 Source: [3]

19 Service Methane Number Procedure in the EMRP-Project Measurement of the SMN for a matrix of gases with two test engines. Comparison of the results with the MWM- and AVL-correlation and possibly with other correlations from the literature. Decision which method shall be recommended. If necessary, development of a new correlation. 1. Juni 2015 Folie 19

20 Thank You!

21 Kick-Off-Meeting Methane Number of LNG References [1] FVV (1971): Erweiterung der Energieerzeugung durch Kraftgase. Untersuchungen zur Übertragbarkeit der am CFR-Motor gefundenen Ergebnisse auf andere Motoren - Gültigkeitsbereich der Methanzahl. Teil Aufl. Frankfurt / Main. [2] Malenshek, Martin; Olsen, Daniel B. (2009): Methane number testing of alternative gaseous fuels. In: Fuel 88 (4), S DOI: /j.fuel [3] Rahmouni, C.; Brecq, G.; Tazerout, M.; Le Corre, O. (2004): Knock rating of gaseous fuels in a single cylinder spark ignition engine. In: Fuel 83 (3), S DOI: /S (03)00245-X. 1. Juni 2015 Folie 21