METHOD FOR MEASURING HYDROCARBON GASES WHEN THEY ARE DISCHARGED THROUGH SHUT-OFF AND CONTROL VALVES AT INSTALLATIONS OF OIL AND GAS PROCESSING ENTERPRISES Russian patent published in 2021 - IPC G01F1/26 

FIELD: gas mass measurement.

SUBSTANCE: invention relates to methods for gas mass measurement. According to the method, when gases are discharged through shut-off and control valves into the flare header, the diameter of the flow area of the valve is determined. The excess pressure and density of the gas in the container are measured during a specific time period from the beginning to the end of the discharge of gas. The flow area of the valve, the mass flow and the mass of discharged gas are subsequently calculated. Additionally, the opening degree of the shut-off valve element is measured according to the height of the stem’s rise or the angle of rotation of the control handle. After that the pressure in the flare header is measured. Then the flow area of the valve is determined in accordance with mathematical correlations. The local resistance coefficient is determined on the basis of graphical correlations in accordance with the type of shut-off and control valves and the corresponding opening degree of the shut-off valve element. When hydrocarbon gas M_hg is discharged through the shut-off and control valves, its mass is calculated according to the formula:

where ζ is the coefficient of local resistance of the shut-off and control valves; F_fa is the flow area of the shut-off and control valves, m²; t is the time from the start to the end of the discharge of hydrocarbon gases, h; P_hg is pressure of hydrocarbon gas in the pipeline in front of the valve during discharge, kgf/cm²; P_f is gas pressure in the flare header, kgf/cm2; ρ is the density of the discharged hydrocarbon gas, kg/m3.

EFFECT: invention improves accuracy of measuring the mass of hydrocarbon gases when they are discharged into the flare header. It also expands the practical applicability of the method for technological units of oil and gas processing enterprises in cases of using other types of shut-off and control valves (a choke, a valve, a gate, a gate valve, a shutter) when discharging hydrocarbon gases into the flare header with the full or partial opening of the valve shut-off element.

1 cl, 6 dwg, 1 tbl