Results 1 - 10 of 360
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[en] The contribution is aimed on the analysis of Y(Q) characteristic of centrifugal pump. The main attention is concentrated on the impeller of high specific speed, especially on the diagonal pumps. It is derived, that stability of Y(Q) curve depends on the dissipative function. The analysis concludes that very important is the design of the interior of spiral case and distributor to achieve a stable Y(Q) characteristic curve.
[en] The article presents the results of investigation of the effect of geometrics of a double-volute outlet hydraulic passage on the magnitude and direction of acting of the radial reaction forces in a between-bearings single-stage centrifugal pump with a double entry impeller. The investigation has been performed with the use of a computing experiment. Characteristic curves as well as values and directions of the radial thrust have been compared for three variants of outlet hydraulic passages differing in the width at their entrance. (paper)
[en] The paper features the results of the fluid flow calculation in the channels of varying geometry of the centrifugal pump for the service water in the methanol production chain. Modeling of the flow in ANSYS CFX allowed developing recommendations on adjusting the impeller’s profile, significantly decrease the cavitation wear and increase the lifetime by several times. (paper)
[en] The article deals with the effect of the vanes diffuser geometric components at the inlet (downstream of an impeller) and at the outlet (upstream of the impeller) on the shape and steepness of the Q-H-curve. Intermediate stage comparative curves based on centrifugal pump tests are given with corrections to the vanes diffuser components were made. This allows changing steepness of the Q-H-curve. Comparative tests of the intermediate stage with different types of vanes diffusers (with continuous crossover channels and discontinuous crossover channels) are shown. (paper)
[en] Complete text of publication follows. Centrifugal pumps powered by downhole motors have been used for decades to lift fluids from oil wells. These pumps and their coupled motors are commonly referred to as 'Electrical Submersible Pumps' or 'ESPs'. This paper outlines some of the classical considerations for analyzing, designing, and monitoring of dowhhole centrifugal pumps. The term 'ESP' is always used as an abbreviation for 'downhole centrifugal pump powered by a coupled electric motor'. Experience has shown that proper design and application of ESP equipment rests on three pillars: understanding the well's productivity, understanding the fluid ratios and phase behavior of the fluids produced by the well, careful analysis of activity in each stage of the actual installed pump. Designing on ESP installation for a well that produces liquid only is a quite straightforward procedure because the operating conditions for the submersible pump are ideal. Increasing amounts of gas production, however, complicate the selection of ESP equipment and require, many times, the use of a computer. Unknown well inflow conditions can be accommodated if a variable speed drive (VSD) is used to provide the electric supply to the ESP motor. In this paper, installation designs are detailed for the most common cases encountered in the field: (a) pumping a single-phase liquid, (b) producing free gas along the liquids, and (c) using a VSD unit to drive the installation. Field example of ESP installation design in Sarir oil field of Libya is discussed as well as the optimization process concerning the ESP field application. (author)
[en] The article presents static calculation of an automatic machine for unloading of rotor axial forces in a high-pressure and high-speed pump. Analysis of the rotor displacement influence to values of mass flow rate and pressure in the unloading chamber of the unloading system is given. The main geometric parameters of the system are obtained. (paper)
[en] A COIL (Chemical Oxygen-Iodine Laser) of 2.2 kW output power has been developed in Korea. The effects of stability and uniformity of the BHP(Basic Hydrogen Peroxide) jet columns on the operation of the COIL are reported. In this paper, the uniform jet speed distribution of jet SOG (JSOG) in a supersonic COIL is achieved by using the centrifugal pomp. And the vane plate in front of BHP jet plate is installed to suppress the turbulent BHP flow generated by the centrifugal pump. The stability and uniformity of BHP jet columns are increased by installing the vane plates, Substantially, the chemical efficiency is increased up to 21.7%
[en] The authors analyzed the reasons of low efficiency under different operation condition based on the performance test and CFD numerical simulation approach. And the analysis focuses on the relationship between pump efficiency and inner flow characteristics. In order to improve the internal flow and increase efficiency of the pump, some draughting methods of improving the internal flow structure have been proposed, and some new impellers were developed by these methods. The main geometric parameters of the impellers, such as diameter, width and installation of the size, were consistent with the original impeller. The experimental results show that the efficiency of new impellers was improved significantly. The authors' work has opened up a new direction for further improving the efficiency of the low specific speed centrifugal pump.
[en] In order to find the effects of blade arrangement on impeller radial force, a double-suction centrifugal pump with two impeller configurations is investigated by using CFD approach. The two impeller have same geometry, same blade number, and different blade arrangement. One is staggered impeller in which the blades are arranged with half of blade phase angle staggered in circular direction, another is traditional symmetrical impeller with symmetrical blade arrangement. Results show that the radial force vector diagram for symmetrical impeller is a hexagonal, while it is nearly a circle for staggered impeller. The staggered impeller results no radial force saltation which exists in symmetrical impeller. The blade passing frequency dominates the radial force fluctuation in symmetrical impeller, while this frequency is almost not existed in staggered impeller. The results indicate that staggered blade arrangement can significantly reduce radial force fluctuation in double-suction centrifugal pump
[en] Numerical simulation on the two-stage centrifugal compressor with Low Solidity Vaned Diffuser (LSVD) for HFC-134a turbo-chiller was performed using a commercial code. The comparative study with experimental results from other compressor was also investigated to testify the simulation schemes. The numerical analysis was separately simulated for each stage of the compressor and the effect of impeller-diffuser flow interaction was considered. Setting angle of the diffuser vane changed in the range of 15 .deg. and the effects on its variation were discussed in detail including the flow analysis in the passage of the compressor. The vane setting angle obtained from the preliminary design was slightly adjusted to the optimal value by the performance enhancement in terms of pressure recovery and flow characteristics