ASSESSMENT OF THE RELIABILITY OF LIQUEFIED NATURAL GAS SAMPLING
UDC: 0681.05.08
DOI: 10.33285/0132-2222-2021-4(573)-16-22
Authors:
SAFONOV ANDREY VASILIEVICH 1
1 Oil and Gas Measuring Technologies, Moscow, Russian Federation
Keywords: liquefied natural gas, sampling, estimation of sampling uncertainty
Annotation:
The optimal solution when assessing the reliability of liquid phase sampling of liquefied natural gas (LNG) is the average integral method of assessment using multi-point tubular or slit probes. When assessing the reliability of sampling, it is necessary to place the sampling zone in a place that ensures a homogeneous state of the flow, control the flow rate and back pressure to avoid the formation of a gas phase in the sampling zone. To determine the representativeness of the selected sample, it is necessary to evaluate the difference between the values of the selected quality indicator of the LNG batch obtained as a result of the analysis of the selected sample and the base value of this indicator for this LNG batch. The reference value of the selected value should be used as the reference value of the quality indicator when sampling the sample obtained during the first, middle and last hour of shipment/loading of the tanker or tank. The compared quality indicators require evaluation of the values of the most significant parameters when determining the amount of transmitted LNG energy, for example: the density of the mixture and the methane content, which are the main ones when determining the mass and amount of transmitted LNG energy. The operation of the sampling system is considered reliable if this sampling system provides representative samples with average integral values of the deviation of the density or methane content between the base and control values in the range of 5…10 %.
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