Problems structure-parametric optimization of oil pipelines by frequency-regulated electric drive

Abstract

In recent years, much attention is paid to the development of variable frequency drive (frequency-adjustable electric drive) for pumps of pipeline transport of oil. One of the most important problems that must be addressed during the optimization of the technological process of pumping using frequency-adjustable electric drive is the choice of the number of pumps, frequency converters and electric motors rotation speed. In the article the objectives and criteria of optimization of pumping oil by pipeline with frequency-regulated drive the pumps are discussed. For drives of main pump for pumping stations are used high-voltage electric motors. Each motor together with the pump can be switched on or off, and each motor can be powered directly from the network or from the frequency converter. While there are many possible structures as each of pump stations and technological area as a whole, with different number and combination included pumps, motors and frequency converters. In the modern system of pumping out «from the pump in the pump» mode all pumps technological area of interrelated. Changing the mode of one of the pumps changes the mode of pumping technological area, and, consequently, regimes of all other pumps. The modes of operation of all the pumps, motors and frequency converters of all pump stations technological area are interrelated. Therefore, when optimizing the process of pumping motors, frequency converters and pumps should be regarded as components of a single process. Thus, related how the composition of a component technological area and modes of their work. Therefore optimization of pumping oil is advisable to use structural-parametric optimization, which is a combination of structural and parametric optimization. Structural optimization using frequency-adjustable electric drive is the determination of the optimal number and combination included in regulated and non-regulated pumps. Parametric optimization when using a frequency regulation lies in selecting the optimal speed of rotation of each of the pumps. All criteria of optimization of modes pipeline using frequency-adjustable electric drive proposed to divide into three groups: energy criteria, the purpose of which - reduction of energy costs for pumping, technological criteria, the purpose of which is the optimization of technological parameters and to increase reliability, and operational criteria, which purpose is to reduce the cost of maintenance and repair of objects of the main pipeline. A block diagram of the structural and parametric optimization of the technological process of pumping with two contours optimization is offered. In the contours of the structural and parametric optimization the same or different criteria optimization can be used. The principles of selection criteria optimization are proposed.