Centrifugal Oil Pump Research Articles

Влияние масштабирования на энергоэффективность нефтяных насосов

Multistage centrifugal oil pumps have been used in oil production for about a century. The design of their stages has not changed for a long time, only the geometric dimensions vary, which still makes it possible to improve the performance characteristics of pumps. One of the widely used methods of changing the geometric dimensions of the stages is the scaling of stages to other dimensions. Pres-sure and flow characteristics of scaled stages are recalculated by similarity criteria and practically coincide with the results of bench tests. The efficiency of stages scaled from larger to smaller di-mensions is always lower than that of the original stages. The purpose of this work was to establish the reasons for this phenomenon. The influence of such factors as the flow channel roughness, leak-age and disk friction was evaluated. It is shown that roughness and leakage are the determining fac-tors. The similarity method showed that as a result of scaling the effect of roughness can be reduced and even compensated by increasing the shaft speed, which was confirmed by calculations and bench tests.

Identifying Centrifugal Pump Effectiveness Through Utilizing OEE Measures as a Basis Towards Optimum Process Stability

The present global competitive within the petroleum industry obliges companies to improve production performance continually. In this paper, Overall Equipment Effectiveness (OEE) used as improvement driver tools that measure various types of production losses and indicate the area of process improvement. The study approach attempts to measure the effectiveness of the centrifugal oil pump during one year of operating based on the historical data acquired. Then used this gained data of the OEE metrics in order to predict the pump effectiveness over the three years. Monte Carlo simulation method used to prognosis the machine behavior patterns in the future and estimating the effectiveness of the pump system. Also, it supports management for clear understanding to draw their maintenance strategy in advance and identifies the opportunities to reduce wastages of time and resources. Further, the results show how individual OEE factors influence the overall productivity and efficiency of the oil pump. This identification will contribute not just to improve the maintenance plan but also will protect the equipment from early deterioration and achieve process stability. OEE is a globally recognized best practice measure to systematically improve processes for higher efficiencies and better productivity, ultimately leading to lower manufacturing costs and higher profitability.

The method to remove parts from the multi-step oil well centrifugal pump housing on a workbench

Repair of centrifugal oil pumps requires their total tear-down, with removal of steel parts from the cylindrical housing made of thick-walled steel tubes. This paper describes the technology of removal of steel parts from the tube using an air-driven hammer with a piston of relatively small weight of 40 kg. The complete tear-down of the deep-well centrifugal pump is implemented using a facility with a guiding frame. The frame accommodates the mutually appressed air-driven hammer, a nozzle with a conical seating surface, a tube section with a side window and a stepped flange adaptor. The latter is pressed to the end face of the pump housing. The other end of the housing is butted on the energy sink fastened on the guiding frame. The described facility has a rod passed through the open end hole in the energy sink and along the opening of the housing, which interacts with the parts in the housing via one end and with the drive via the other end.

Investigation on the characteristics of oil supply system for a hermetic variable speed rotary compressor

Abstract A hermetic variable speed rotary compressor has a substantially vertically oriented drive shaft, by which the oil is driven upwards and delivered to the lubricating components. To avoid oil starvation or excessive oil supply over a wide range of working speed, it is essential to understand the flow characteristics in such a centrifugal oil pump. In this study, a novel test rig has been built to perform the measurements of oil flow rate under various operating conditions. Several key design parameters in relation to the flow rate such as oil inlet diameter, oil viscosity and oil level height in oil sump have been discussed in detail. The results indicate that the oil flow rate increases up to the speed at which the flow stagnation appears and then starts to slightly decrease with the speed. The stagnation speed decreases with the oil inlet diameter but increases with an augment in oil level height. The oil viscosity does not considerably affect the stagnation speed. Based on the simulated results, it is found that the gas region at oil inlet expands and the effective oil flow area reduces when the rotational speed is high enough. Such behavior of oil flow could be one potential explanation to the occurrence of flow rate stagnation.

INCREASING THE CENTRIFUGAL PUMP RELIABILITY FOR OIL COLLECTION AND PUMPING SYSTEMS

Background Features of the working conditions of submersible centrifugal oil pumps determine the specific requirements for the shape of the characteristics of the pumps. Fulfillment of these requirements allows preserving the high efficiency of pumps under operating conditions and ensuring the reliability of their operation. Aims and Objectives Substantiation of requirements for the submersible centrifugal pumps characteristics. Results It is revealed that a large steepness of characteristics at low feed rates is economically unprofitable. During prolonged operation of the pump in conditions of ascending the impeller and a large gap between the lower sealing ring of the impeller and the mating surface of the guide vane, a self-oscillating process can occur, leading to rapid wear of pump stage parts.

Dynamic analysis of centrifugal machines rotors supported on ball bearings by combined application of 3D and beam finite element models

This research paper is aimed to investigating rotor dynamics of multistage centrifugal machines with ball bearings by using the computer programs “Critical frequencies of the rotor” and “Forced oscillations of the rotor,” which are implemented the mathematical model based on the use of beam finite elements. Free and forces oscillations of the rotor for the multistage centrifugal oil pump NPS 200-700 are observed by taking into account the analytical dependence of bearing stiffness on rotor speed, which is previously defined on the basis of results’ approximation for the numerical simulation in ANSYS by applying 3D finite elements. The calculations found that characteristic and constrained oscillations of rotor and corresponded to them forms of vibrations, as well as the form of constrained oscillation on the actual frequency for acceptable residual unbalance are determined.

Performance correction chart of centrifugal oil pump for handling viscous liquids

The viscosity of oil has a pronounced impact on the operating conditions of the pump. Pumps that are tested with water but are used to transport viscous fluids must have their head, flow, and efficiency values corrected to approximate their performance with the viscous fluid. In this article the hydraulic characteristics of centrifugal oil pumps with different specific speeds for pumping viscous fluids are studied experimentally. The relationship of correction factor with performance characteristics, rotational speed and oil viscosity is investigated. According to the affinity law by KSB, the performance correction chart of flow rate, head and efficiency is plotted. The typical calculated examples show that the calculated results by the diagram methods are consistent with the experiments.

Experimental Research on Performance of Aircraft Tanker Truck with Different Oil Pump in the Plateau

Introduced the basic situation of aircraft tanker truck, carried out the performance tests of the tanker truck with ZX120-100 and ZX120-100-GY self-suction oil pump in the plateau. The test result shows that the self-suction capability of ZX120-100-GY centrifugal oil pump is better than ZX120-100 centrifugal oil pump, and refueling performance of 2004-12000 aircraft tanker truck with ZX120-100-GY centrifugal oil pump is good which can afford the demand of the aircraft.

Analytical and CFD modeling of the fluid flow in an eccentric-tube centrifugal oil pump for hermetic compressors

A model is presented for calculating the volume flow rate in an eccentric-tube centrifugal oil pump for reciprocating compressors. The oil pump assembly consists of a pick-up tube with an inclined inlet that is mounted off-center with the crankshaft symmetry axis. The pick-up tube is connected to the shaft channel, a helical groove machined on the crankshaft that facilitates the supply of lubricant to the bearings. The analytical models for the pick-up tube and shaft channel were developed independently and were coupled via a numerical procedure to determine the steady-state volume flow rate in the assembly. The steady-state results were verified against a CFD model, which was also used to evaluate the fluid flow in the oil pump assembly during a start-up transient. A parametric analysis was conducted to quantify the influence of some oil pump geometric parameters, such as the pick-up tube diameter and the shaft eccentricity.

Investigations of groove seal wear in centrifugal oil pumps

The paper presents the results of study of the factors affecting the wear rate in groove seal components used for crude oil centrifugal pumps. A test technique is proposed for the groove seal components that forecasts their wear resistance in specified conditions.

Blade Exit Angle Effects on Performance of a Standard Industrial Centrifugal Oil Pump

The effects of blade discharge angle on the performance of a standard industrial centrifugal oil pump of type 65Y60 were investigated experimentally as the pump handled both water and viscous oil. A one-dimensional hydraulic loss model was established to identify such effects mathematically. The effects have been estimated analytically by using the model at various viscosities. The results showed that the blade discharge angle has significant but equal influence on the head, shaft power and efficiency of the centrifugal oil pump at various viscosity conditions. For any viscosity, the total hydraulic loss in the impeller and volute rises with increasing blade exit angle. The diffusion loss in and behind the impellers as well as the friction loss in the volute are noticed in the pump, especially for highly viscous liquids. The hydraulic loss in the impellers is about 0.8-0.6 times the loss in the volute. In order to improve the pump performance, the hydraulic loss in the volute must be kept as small as possible.

Operation of centrifugal pumps in off-design conditions

The special features of operation of centrifugal oil pumps in underload conditions are discussed. It is shown that the vibrodynamic characteristics of the pumps are linked with the delivery operation conditions. The cavitation characteristics of screw centrifugal stages are compared. Recommendations are offered for normal pump operation in startup and off-design conditions.

Method for Analyzing the Performance of Centrifugal Oil Pumps

Method for Analyzing the Performance of Centrifugal Oil Pumps

Features of the characteristics of submersible centrifugal oil pumps

Features of the characteristics of submersible centrifugal oil pumps

Experimental Investigations of Performance of a Commercial Centrifugal Oil Pump

Experimental Investigations of Performance of a Commercial Centrifugal Oil Pump

Influence of the number of impeller blades on the performance of centrifugal oil pumps

Influence of the number of impeller blades on the performance of centrifugal oil pumps

Experimental investigations into the performance of a commercial centrifugal oil pump

Experimental investigations into the performance of a commercial centrifugal oil pump

The “sudden-rising head” effect in centrifugal oil pumps

By Li Wen-Guang, Associate Professor, Ph.D, Hydraulic Machinery Division, Gansu University of Technology. Experimental results in centrifugal oil pumps whose specific speed is less than 90 have shown that while oil viscosity is lower than a certain value, the head increases with rising viscosity. However, once the oil viscosity exceeds that value, the pump head decreases with rising viscosity [1,2,3]. This is called the “sudden-rising head” phenomenon.

Design and Operation of the Oil-Turbine Ultracentrifuge

The development of the oil-turbine ultracentrifuge, from the first model built in 1925 to the latest, is traced, with special attention being given to the principles of design for maximum resolving power in the analysis of mixtures as the lowest expenditure of energy. The efficiency of various types of rotors combined with centrifugal or screw-type oil pumps is reported. By proper attention to design, it has been possible to attain an efficiency at 60,000 r.p.m. of 40 percent in the oil turbines and an over-all efficiency of electric motor, oil pump, and oil turbines of 28 percent. The actual power consumption under these conditions is slightly over 1 kw, which appears to be somewhat better than has so far been attained with the air-turbine ultracentrifuge of comparable design. The frictional resistance of the rotor rotating in hydrogen at 20 mm pressure is 300 watts, 32 watts representing gas friction. The cost of electricity, cooling water and hydrogen for operating the latest rotor and assembly at 60,000 r.p.m. exclusive of the vacuum system and recording instruments, is 9¢ per hour, with electric power at 1.54¢ kw-hr., water at 6.4¢/cu.m, and hydrogen at 64¢/cu.m. The corresponding cost for an early model rotor and assembly was 28.7¢ per hour.

Discussion of “O’Brien on Centrifugal Oil Pump”

Discussion of “O’Brien on Centrifugal Oil Pump”