LNG接收站到港天然气组成预测

Prediction of natural gas composition in LNG terminal unloading port

关键词:  LNG接收站  组成  计量  发热量  密度  预测 

Key words:  LNG terminal  composition  measurement  calorific value  density  prediction

摘要:

LNG贸易交接总发热量的计算需要采用到港天然气组成分析数据,但如果在卸货过程中取样分析故障无法获得较理想的天然气组成,就可以采用推算的预测方法推测到港天然气组成。预测方法是根据天然气组分沸点,建立液相和气相的关系式,根据蒸发率将装港天然气组成进行多次蒸发迭代得到到港天然气的组成。经过对比分析,得出预测法和实际取样分析得到的组成、计算出的单位体积发热量和LNG密度相差较小,预测法具有参考价值,可为LNG接收站接卸过程取样分析结果和买卖双方贸易结算提供参考数据。 

Abstract:

The calculation of the total calorific value of the LNG trade measurement requires the use of the natural gas composition analysis data. But when the sampling in the unloading process fails, the prediction method can be used to calculate the unloading port natural gas composition. The prediction method is to establish the relationship of liquid and gas phase based on the boiling point of natural gas. According to the evaporation rate, unloading port natural gas composition is obtained by multiple iteration to loading port natural gas composition. Through comparative analysis, it is concluded that the deviations of natural gas composition, the calorific value per unit volume and LNG density are small between the predicted method and the actual sampling analysis. The prediction method has reference value for LNG terminal loading and unloading process sampling analysis, as well as buyers and sellers trade settlement.