DEFINITION OF CALCULATION DISTURBANCE FOR AUTOMATIC CONTROL SYSTEMS PRESSURE PUMPING STATIONS TRUNK OIL PIPELINES

Abstract

The automatic control system (ACS) pressure pumping station must ensure testing of the estimated disturbance associated with the shutdown of the pump at the next pump station (PS), or start one pump at the previous PS [1,2]. Estimated disturbance occurs as the result of several processes: - the occurrence of the initial perturbation, education waves flow and pressure at the station, where there was a start-up or shutdown of the pump; - the spread of this disturbance through the pipeline section between the point of origin of the perturbation and the station where the ACS pressure and attenuation as we move, reducing the amplitude and rise time. The wave, which reached ACS stantsiis pressure is called the incoming wave; - the interaction of the incident wave with a pumping station. The regulatory system should have such a speed that it creates a pressure wave had the opposite sign of the slope of the front and not less than the rise time estimated disturbance. In this paper, the expression for determining the initial disturbance that occurs when the pump is turned off at an intermediate transfer station without the tank farm. Pressure pump performance approximated full second-order polynomial (all the coefficients are different from zero). To calculate the attenuation slope coefficient of wave front defined linearization of unsteady flow of fluid through the hydraulic gradient value of the derivative of consumption. To determine the minimum length of the decay is taken to be 50 km. The interaction of the incoming wave is formed with a pumping station to the station reflected pressure wave and flow, moving along the conduit in a direction opposite to the direction of motion of the oncoming wave. The relationship of the pressure waves and flow rate determined by the formula «Zhukovsky». The equation for determining the slope of the front of the reflected wave at a certain steepness of the wave front the pressure considering the nonlinearity of the discharge characteristics of the station. Calculations to determine the calculated perturbations for pipeline DN 500 - 1200 mm.