Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts Determination of the Service Methane Number Peter Eilts, Lennart Klare, 22.08.2017 Institute of Internal Combustion Engines
Outline • Knocking • Methane Number • Service Methane Number • Experimental Setup • Experimental Procedure • Results • Conclusions 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 2 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Outline • Knocking • Methane Number • Service Methane Number • Experimental Setup • Experimental Procedure • Results • Conclusions 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 3 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Knocking Flame propagation with normal combustion 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 4 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Knocking Flame propagation with knocking combustion 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 5 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Knocking Cylinder pressure with knocking combustion Flame speed ca.10 … 25 m/s 250 … 300 m/s 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 6 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Outline • Knocking • Methane Number • Service Methane Number • Experimental Setup • Experimental Procedure • Results • Conclusions 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 7 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
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. 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 8 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Methane Number AVL, MWM and NPL 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. Besides the AVL and MWM correlation there are further methods in the literature. In this project NPL has developed another correlation which is also based on the AVL data. 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 9 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
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). 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 10 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Outline • Knocking • Methane Number • Service Methane Number • Experimental Setup • Experimental Procedure • Results • Conclusions 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 11 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
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. For mixtures of Methane and Hydrogen the SMN is equivalent to the MN. 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 12 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Service Methane Number SMN of NG-Propane-mixtures at different engine speeds [1], Fig. 5.14 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 13 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Outline • Knocking • Methane Number • Service Methane Number • Experimental Setup • Experimental Procedure • Results • Conclusions 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 14 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Experimental Setup Engine 1 • Engine: externally supercharged 1-cylinder 4-stroke SI-engine with a displacement of 600 ccm. Compression ratio 12.5:1. Connected to a dynamometer. • Fully indicated engine (intake-, cylinder- and exhaust pressure for every 0.1 degree crank angle) • Multi point gas injection in the intake pipe ( 2 gas injectors) • Stoichiometric operation 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 15 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Experimental Setup Engine 2 • Engine: externally supercharged 1-cylinder 4-stroke SI-engine with a displacement of 200 ccm. Compression ratio 12.5:1. Connected to a dynamometer. • Fully indicated engine (intake-, cylinder- and exhaust pressure for every 0.1 degree crank angle) • Single point gas injection in the intake pipe • Stoichiometric operation 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 16 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Experimental Setup Engine 1 and 2, pressure indication Equipment to measure the pressure in the combustion chamber, intake and exhaust system: • Pressure transducer [2] • Charge amplifier • Evaluation unit 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 17 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Experimental Setup Knock detection • In the „KiBox“ software the knock detection algorithm ist implemented [3] • 1. Find pressure maximum • 2. Smooth the signal through a moving average • 3. Subtract the moving average signal from the raw signal 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 18 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Experimental setup Knock detection • In the „KiBox“ software the knock detection algorithm ist implemented [3] • 4. Rectification • 5. Selection of reference and knock window • 6. Calculation of the knock an reference integral If the knock ratio reaches a certain value it is a knocking cycle 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 19 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Experimental Setup Definition of the knock frequency The knock frequency ist the percentage of knocking combustion cycles compared to the total number of all combustion cycles in a measured time. It is used to characterize the knocking intensity. 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 20 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Experimental Setup Test gases Component CH 4 C 2 H 6 C 3 H 8 n-C 4 H 10 i-C 4 H 10 n-C 5 H 12 i-C 5 H 12 n-C 6 H 14 N 2 CO 2 AVL-MN Mix 1 78.80 14.0 3.40 0.90 1.10 0.15 0.15 1.5 59 Mix 2 84.52 12.9 1.50 0.21 0.22 0.03 0.02 0.6 69 Mix 3 91.80 5.70 1.30 0.15 0.17 0.04 0.04 0.8 77 Mix 4 81.69 13.38 3.67 0.27 0.28 0.01 0.01 0.69 65 Mix 5 87.89 7.27 2.92 0.71 0.65 0.10 0.11 0.35 66 Mix 6 95.01 2.62 0.73 0.20 0.15 0.06 0.09 0.22 0.54 0.38 82 Mix 7 97.876 1.00 0.50 0.21 0.18 0.016 0.018 0.2 90 Mix 8 99.68 0.09 0.03 0.01 0.01 0.005 0.005 0.17 98 Mix 9 99.4 0.3 0.3 84 Mix 10 99.6 0.2 0.2 89 Mix11 99.8 0.1 0.1 94 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 21 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Outline • Knocking • Methane Number • Service Methane Number • Experimental Setup • Experimental Procedure • Results • Conclusions 22. August 2017 | Peter Eilts, Lennart Klare| Service Methane Number | Slide 22 Institute of internal combustion engines Prof. Dr.-Ing. Peter Eilts
Recommend
More recommend
