METHOD FOR AUTOMATIC CONTROL OF INHIBITOR FEED TO PREVENT HYDRATE FORMATION AT LOW-TEMPERATURE GAS SEPARATION PLANTS OPERATED IN EXTREME NORTH Russian patent published in 2019 - IPC E21B34/16 E21B37/06 

FIELD: mining.

SUBSTANCE: invention relates to mining and can be used for prevention of hydrate formation and destruction of hydrates at installations of low-temperature separation (LTS) of gas. Inhibitor is supplied to points before protected sections, complex of which is low-temperature gas separation unit LTS. APCS provides supply of inhibitor in amount sufficient to prevent hydrate formation, minimizing its consumption. To this end, APCS controlling: flow rate of gas-liquid mixture at inlet and outlet of separator of first separation stage; temperature and pressure of gas-liquid mixture at inlet line of plant, in separator of first separation stage, intermediate and low-temperature separator; concentration of the inhibitor in the aqueous solution at the separators output of the separator of the first separation stage separator, intermediate and low-temperature separator; concentration and flow rate of the regenerated inhibitor supplied to each protected section of the plant. Flow rate of the regenerated inhibitor is controlled by a PID regulator controlled valve, the PV feedback of which receives a signal from the flow sensor of the regenerated inhibitor. Input of SP setting of this PID regulator is supplied with the calculated flow rate of the inhibitor corrected by the actual concentration of the regenerated inhibitor. Correction unit calculates this correction, the first input of which is fed with a calculated signal APCS mass flow rate of the inhibitor for the protected section is sufficient for the required reduction of the hydrate formation temperature. And to the second input of the correction unit, a signal is sent from the output of the CV PID-controller of maintaining concentration of the inhibitor in its aqueous solution at the outlet from the protected area. Feedback signal of the PV PID regulator of the concentration of the inhibitor is supplied with a signal from the concentration sensor of the aqueous solution of the inhibitor set at the outlet of the inhibitor from the protected area. And to input of setting SP PID-controller of concentration of inhibitor signal of calculated APCS values of concentration of an aqueous solution of the inhibitor, which eliminates hydration in the protected area.

EFFECT: technical result consists in optimization of inhibitor consumption to prevent hydrate formation at LTS gas plants operated in Extreme North.

4 cl, 4 dwg