METHOD FOR METERING LIQUEFIED HYDROCARBON GASES DURING STORAGE IN TANKS Russian patent published in 2016 - IPC G01F1/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to metering liquefied hydrocarbon gases (hereinafter LHG) and, in particular, to measurements of weight of LHG during storage on automobile gas-filling stations (hereinafter AGFS) and multifuel filling stations (hereinafter MFS). Method of metering liquefied hydrocarbon gases (LHG) stored in a tank comprises steps of: determining component composition of LHG by means of chromatographic analysis and determining molecular weight µ of certain components using a processing unit. Then measuring density value ρ_l of liquid phase of components included in composition of LHG by means of measuring density; determining level H of interface of LHG in tank by means of measurement of level of interface. Further, temperature t_l of liquid phase of LHG is determined and temperature t_u of LHG vapour phase in tank by means of temperature sensors. Then measuring density ρ_p of vapour phase of components included in composition of LHG, by means of measuring density or determining density ρ_u of vapour phase of components, included in composition of LHG, from component composition and temperature of liquid phase of LHG in tank by means of a processing unit. Further, determining from level H of interface of LPG in tank corresponding to said level value of volume V_l20 of liquid phase of LHG in tank on measured level H using known calibration table of tank, composed at temperature 20 °C, by means of processing unit to calculate volume V_l(t_l) of liquid phase of LHG in tank at temperature t_l using formula V_l(t_l)=V_l20·[1+2·α_st·(t_l-20)] by means of processing unit, determining volume of LHG vapour phase in tank at determined temperature t_u of vapour phase of LHG as difference between full capacity of tank at said temperature and volume of liquid phase LHG in tank at said temperature by formula V_u(t_u)=V_D20 ^res·[1+2·α_st·(t_u-20)]-V_l(t_l), where V_D20 ^res is previously known actual capacity of tank at temperature 20 °C. Then calculating mass M_l of liquid phase LHG as product of volume V_l(t_l) of liquid phase in tank on measured density value ρ_l of liquid phase of LHG, c mass M_n of LHG vapour phase as product of volume V_u(t_u) occupied by vapour phase of LHG in tank, on measured or determined density ρ_u of LHG vapour phase, total mass M₀ of LHG in tank through summation of mass M_l of liquid phase and mass M_n of LHG vapour phase in tank.

EFFECT: high accuracy of metering LHG during storage in tanks.

4 cl, 7 tbl