Tag Archives: магистральный насос
MEASURES TO IMPROVE ENERGY EFFICIENCY TECHNOLOGICAL PROCESS LINEAR INDUSTRIELLE SENDING STASJONER (LPDS)
Currently relevant is the question of enhancing the efficiency of the main oil pipelines.
The share of energy costs in the pipeline transport of oil is 30% and this figure continues to grow. This growth is caused by the increase in oil production and a correspondingly increased volumes. The dependence of energy consumption in freight rail turnover is a power-law dependence. Therefore, with an increase of turnover of oil specific energy consumption is not reduced, but increases in proportion to the turnover to the extent of 1.75. For this reason, it is necessary to carry out activities for energy efficiency and energy savings.
The primary power consumer in the pipeline transport are pumping units at OPS and LPDS. When monitoring operational characteristics of pump units is possible, energy savings of 9 to 21 % of the costs of energy for oil transportation: the upper point is due to structural changes in pumps, the lower only through the maintenance of the units in their actual condition.
Comprehensive monitoring of the technical state of each pump unit one step closer to the technology improvement of trunk pipeline transportation of oil.
The article describes the technical energy saving measures to improve energy efficiency of technological processes LPDS, developed and justified measures to improve the energy efficiency of pumping units.
APPROXIMATE ESTIMATE OF THE CYCLIC LOADING REDUCTION OF THE PIPELINE WHEN USING VARIABLE-FREQUENCY ELECTRIC DRIVE OF MAIN PUMPS
Currently, the regulation of the mode of pumping oil through main oil pipelines is made by selecting number of main pumps units (MP) or, using cyclic pumping. Disadvantage of this method of pumping is the work of metal pipes of main pipelines under cyclic loading from the internal pressure change. The use of variable frequency drive (VFD) reduces the cyclical loading of the pipeline. The article considers the problem of performing calculations to determine the cyclic loading during operation of the main pipeline using FVD. In the General case, such calculations can only be performed using algorithms for determining the rotational speed of the MP, structural and parametric optimization. The use of such algorithms requires considerable baseline data and special software. Therefore, the urgent task is the development of simplified evaluation method (forecasting) of cyclic loading during operation of the pipeline using a VFD, convenient in engineering practice.
Simplified methods of assessing the cyclical loading of the existing pipeline, for regulating the modes of which it is expected the installation of VFD are investigated. To perform an approximate estimation of cyclic loading is sufficient to use only the information on the observance of technological modes of the plot. The sequence of approximate estimation of cyclical loading of the pipeline when using a VFD to exclude cyclic pumping is given. It is shown, that for the simplified evaluation of cyclic loading when using a VFD, it helps to consider the total number of inclusions MP without VFD and from the VFD. The pressure change are not defined when you turn MP with a VFD, but are accepted equal to the change of pressure when you turn these MP without VFD.
This article examines the effectiveness of the blocking action for the undervoltage protection from the overcurrent protection in electric mains pump stations and analyzes the impact of non-selective action of the undervoltage protection on the technological process of pumping. The process of pumping oil through main pipelines is continuous. However, when power failure, the motors of the main pumps lose power, that can disrupt the continuity of the technological process of pumping. The protection from power loss are used to detect power failure and taking measures to preserve the continuity of the technological process at oil pumping stations. Undervoltage protection is the main power loss protection when asynchronous drives of the main pumps are used on oil pumping stations. The undervoltage protection must not operate when short circuits in the distribution network of the enterprise to ensure the selectivity of the action. Disable entire section tires switchgear may take place if non-selective trigger occur. It can lead to the stop of the main pumping units and to the total breakdown of the process of pumping oil through the pipeline. Therefore, the protection of the minimum voltage should be blocked when the short circuits in the electrical network of the enterprise. Lock protection minimum voltage at the booster stations is performed from an overcurrent protection input. It isshown that depending on the mode of the supply network lock maximum current input protection may not be effective and undervoltage protection may work selectively. Found resistance range electric supply the range of distances to the fault location at which the failure of MTW and non-selective tripping MNH, at PS, the Investigated transients in the pipeline in the non-selective protection of the minimum voltage. It is shown that depending on the mode of the supply network the blocking may be not effective and undervoltage protection may work incorrect. Found resistance range of electric supply network and the range of distances to the fault location at which an overcurrent protection is not work but undervoltage protection works. Investigated transient processes in the pipeline when protection of the minimum voltage acts not selective.
The article considers the problems of assessing and improving the use of variable frequency drives (VFD) on oil-pumping stations (OPS). Reducing the weight and size and improving the energy performance of frequency converters (FC) is considered. Currently, multi-level inverters with powering from a multi-winding power transformer are the most common. Such transformer increases the weight, volume and cost and reduces energy indicators of the FC. One of the most promising transformerless multilevel inverter, which has no the input transformer, but has the second electronic converter is investigated. This FC will have a number of advantages over existing FC: significantly reduced weight; reduced size; increased efficiency; reduced costs; implementation function of energy recovery in the network.
The influence of the inverter of the VFD main pump on reducing the cost of the electricity, repair of pipeline and of the electro motors is investigated. Research are carried out by performing calculations for the technological section of the existing pipeline. The study showed that the values of all three components in reducing costs are commensurate. Therefore, ignoring any of the components may lead to a substantial increase in the estimated payback period of the inverter. It is shown that the reduction of power consumption for pumping may be less than 3%. Thus on the energy efficiency of VFD at OPS will be significantly affected by the increase in the efficiency of the inverter. Increasing the efficiency of the inverter by eliminating the input transformer, just one percent can lead to increased energy saving up to 45%. It is shown that the use of the transformerless multilevel inverters may to reduce the payback period of VFD at OPS to 11-16%.
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.