PRODUCT INFORMATION
INDEX
DATE
Dep. 8
IC-G-D-30-021e
B
May 2014
FUEL SPECIFICATIONS – US NATURAL GAS
2/5
2.
KOHLER SPECIFICATIONS FOR FUEL GASES
2.1. LOWER HEAT VALUE
Lower heat values of natural gas may be within the following range:
37.5 / 42 MJ/m
n
3
equal to 950 / 1050 Btu/SFC
natural gas
As for engines with a mechanical carburetion system, the maximum permissible variation in the gas LHV is ±5%
with regard to the carburetion point. Greater variations would mean that carburetion must be readjusted.
Engines with an electronic carburetion system must be used where LHV variations can be as high as ±10%;
above this limit, the gas composition has to be continually monitored with an analyzer.
LHV variation in excess of 1%/min. absolute value shall not be allowed over time.
2.2. METHANE NUMBER
The
minimum value for the methane number (AVL) of natural gas
is fixed at 75. For lower values,
contact Kohler .
2.3. SUPPLIED GAS CONDITIONS
In this respect, the following applies:
2.3.1. SUPPLIED GAS PRESSURE AND TEMPERATURE
Since the acceptable gas pressure and temperature at the inlet to the engine depend on the carburetion system
the engine is equipped with, refer to the following Product Information documents for the applicable ranges:
-
IC-G-D-30-007e: Engines with a TECJET 50+ type electronic carburetion system
-
IC-G-D-30-040e: Engines with a TECJET 52 type electronic carburetion system
-
IC-G-D-30-008e: Engines with a mechanical carburetion system
-
IC-G-D-30-015e: Engines with a ELEKTRA 50 type electronic carburetion system
-
IT-G-A-00-011e : Minimum room temperature for operating gas engines
2.3.2. GAS HUMIDITY
The gas relative humidity at the inlet to the gas ramp shall always be less than 80% and by no means shall water
be allowed to condense over the engine components. Therefore, we recommend that gas is fed to the engine at a
temperature exceeding the water dew point by at least 15ºC. Natural gas does not usually imply serious humidity
problems.
2.3.3. OXYGEN IN GAS
For engines with a mechanical carburetion system, the maximum permissible quantity of oxygen (O
2
) in the gas is
2% vol. For higher values or fluctuations greater than ±1% in relation to the carburetion point, it will be necessary
to use engines with an electronic carburetion system and continuous monitoring of the gas composition by an
analyzer.
2.3.4. HYDROGEN IN GAS
The maximum permissible hydrogen (H
2
) content in a fuel gas is 12% vol. H
2
.
4.1.20
O&M_2.002211.810_A_10_2016
