Hydraulic design and balance research of the hotte

2022-08-16
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Research on hydraulic design and balance of deep well pump

hydraulic design of deep well pump

at present, foreign deep well pump manufacturers mainly include Flygt, itt-lowara in the United States, Grundfos in Denmark, Ritz, KSB in Germany, etc From the perspective of imported products, they are very advanced in terms of hydraulic performance, processing technology and material durability For example, the stamping stainless steel well pump technology of Grundfos in Denmark is far ahead, firmly occupying the high-end market Ram pump is a new product that began to be studied in the 1970s internationally At first, the Danish Grundfos company first used stamping and welding methods to produce centrifugal pump impellers In the 1980s, an integral stamping multi-stage pump was introduced In the 1990s, the products represented by the stamping stainless steel well pump of Grundfos company had greater development, which started the brand popularity exhibition of China's wood plastic industry This stainless steel stamping and welding multi-stage pump effectively solves the process that low specific speed centrifugal pump cannot achieve in casting. It has the advantages of simple structure, good performance, high reliability, good sealing performance, advanced production technology and so on, and its hydraulic performance is generally better than that of casting centrifugal pump To sum up, stainless steel stamping and welding well pump, with its excellent performance, represents the development trend of well pump in the world and has broad application prospects

in recent years, many domestic scholars have devoted themselves to the research of deep well pumps and achieved certain results The hydraulic design software pcad2000 is used to redesign the hydraulic part of a well pump The results show that the combination of design experience and hydraulic design software is beneficial to improve the efficiency of well pump A new type of down draft well pump is studied in the literature. The well pump is divided into upper and lower parts. The upper part of the motor is connected with QJ series well pump, and a set of single-stage water pump is installed under the motor The results show that the sealing effect is good, the application scope of the well pump is widened, and the sand content of the pumped medium is increased from 0.01% to 0.1% The effects of impeller inlet and outlet parameters, guide shell geometric parameters and impeller outlet blade area on the performance of submersible pumps are studied in the literature The design method of deep well pump and the calculation formula of the maximum efficiency of deep well pump are proposed in document [14], which provides a set of calculation formulas for the hydraulic design of deep well pump. The relative error of impeller diameter calculation is 2.39%, which can fully meet the accuracy requirements The patent "a general well pump with high efficiency and high head" improves the single-stage head and efficiency by establishing a new hydraulic model The domestic traditional QJ series well used submersible pump is often sometimes called detector, tester, tensile machine, testing equipment, tester and so on. The design concept of water pump and JC series long shaft deep well centrifugal pump is that hydraulic design is higher than structural design, often in order to improve the efficiency of water pump by 1%, regardless of the increase of product cost by 10% In the structural form, most of the pump bodies are fixed and connected with bolts; In order to reserve the position of bolts for the connection part, the inlet diameter of the impeller installed on the pump body is much smaller than the outer diameter of the pump body, which greatly limits the maximum diameter of the impeller, that is, the single-stage head of the impeller The document "a deep well centrifugal pump" puts forward the maximum diameter design method of the impeller of the deep well centrifugal pump, which is characterized by expanding the diameter of the front cover plate of the impeller to the edge of the inner wall of the pump body, so that the impeller diameter reaches a maximum under the condition of the corresponding well diameter. It is matched with the guide shell of the anti guide vane, so that the axial length of the pump body can be reduced to a minimum It adopts the twisted anti guide vane design method, which is different from the anti guide vane of ordinary cylindrical blades. The inlet section of the blade is a three-dimensional curved surface, which can optimize the population conditions The research shows that this design method can not only improve the single-stage head of the well pump, but also improve the efficiency of the pump and realize the full head non overload operation of the deep well centrifugal pump. At the same time, it also points out that it is necessary to study new excellent hydraulic models to ensure that the hydraulic efficiency of the well pump does not decrease The traditional structure and hydraulic design of deep well pump have large axial size, difficult manufacturing of blades, high production cost and low comprehensive economic benefits In order to achieve the goal of high quality and low price, the new type of well pump, especially the high lift well pump with more than three stages, will develop in the future. The single-stage lift will be greatly increased and the axial height of the pump body will be greatly reduced When formulating basic parameters, the national standard "submersible pumps for wells" (GB/T 2816--2002) cancels the provisions on single-stage head in the old standard "types and basic parameters of submersible pumps for wells" (GB/t281691), which also conforms to this development trend

balance of axial force of deep well pump

in production practice, the axial force of pump objectively exists Especially for high lift deep well pumps, if the design and operation are improper, excessive axial force will lead to accidents such as bearing burnout, shaft seal damage and even shaft breakage In many cases, the severity of the problem caused by excessive axial force has exceeded that caused by efficiency, wear and other factors, which has become whether the deep well pump is safe The decisive factor for stable operation [19|. Now the research progress of the axial force balancing device of deep well pump is introduced as follows. Guan Xingfan et al. Proposed a new axial force device of deep well pump, which installs a pair of dynamic and static friction pairs behind the last stage impeller. The new balance shaft package can balance the axial force and basically have no leakage. After using this device, the pump operates reliably and has remarkable energy-saving effect. Lu Weigang et al "A multi-stage centrifugal pump with impeller self balancing axial force is based on the end face sealing structure adopted at the inlet of the impeller, so that the area of the front cover plate of the impeller is larger than that of the rear cover plate of the impeller. The fit between the outer diameter of the front cover plate of the impeller and the guide housing is a clearance fit. The end face sealing pair at the inlet of the impeller is made into a thrust bearing pair that can bear small axial force after confirming that the method is accurate and feasible, so as to realize complete balance by relying on the impeller itself The effect of axial force completely solves the problem of axial force damage, and can also reduce the production cost of the pump By changing the geometric size of the back blade of the impeller, the influence of the back blade on the axial force is studied A balancing drum combination device is proposed, and its principle is basically the same as that of the balancing disc A combined structure of balance drum and balance disc is proposed A floating impeller balancing device with double sealing rings and balancing holes is designed to realize automatic balancing of axial force

in addition, with the development of computer technology, the application of CFD in fluid machinery is gradually maturing. The performance prediction and optimization design of water pump based on CFD has basically reached the level of engineering practicality. At present, the calculation of pump axial force has been involved The internal flow field of submersible pump for well is simulated numerically, the pressure distribution of its axial force is obtained, and the axial force calculation and balance analysis are carried out Therefore, using numerical simulation to calculate the axial force of the beam in the ball screw drive and studying a new method to balance the axial force is an effective method for future research. (end)

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