Synthesis of the Automatic Control System the Temperature of Liquid Flow with Incomplete Measurement the Object State with Distribution Parameters

摘要

This paper presents the tasks of increasing efficiency of controlling the process of viscous liquids indirect induction heating during transportation through pipelines. Specific features of the process of transporting viscous fluids through pipelines are noted. The high viscosity of the pumped fluids leads to high energy costs. One way to reduce energy consumption is to heat the liquid before transporting it. The paper shows, that the process of heating a fluid flow can be described by a mathematical model of an object with distributed parameters. The distribution is due to the uneven distribution of temperature along the radius and the movement of the fluid flow through the heater. The transfer function of the object is obtained in the form of an infinite sum of aperiodic links with transport delay. The structural diagram of the control object is given. The problem of controlling the temperature regime of a fluid flow is formulated. It is shown, that in the case of laminar flow and low thermal conductivity of oil, the temperature distribution over the flow cross section is nonlinear. An estimate of the average temperature over the flow cross section is proposed. The approximation of the temperature distribution is performed by a piecewise linear function consisting of segments of lines with ends at the points of temperature measurement. An automatic control system with feedback on the average temperature over the cross section of the fluid flow is synthesized.