The Design And Research Of3500Five-cylinder Plunger Pump’s Fluid End

The plunger pump used by oil field includes drilling slurry pump, fracturing pump,cementing pump and water injection pump. With the development of oilfield fracturingtechnology, the five-cylinder plunger pump developed with the features of high pressure,large displacement, reliable performance, compact configuration and flexible operation hasincreasingly been the development tendency of fracturing operation. The five-cylinderplunger pump has been designed and researched long ago in foreign countries, while domesticresearch is still relatively backward. At present, the design and research of fluid end with thefeatures of high pressure, large displacement is less in China. In response to this phenomenon,this article based on the existing research results of domestic and overseas makes a researchand design for the kinetic theory of3500five-cylinder plunger pump and the structure of thefluid end.The main works in this paper are as follows:Through the working mechanism research of the five-cylinder plunger pump，this papergives a systematic analysis on the movement of plunge, the change rule of pump flow andpressure and the movement rule of pump valve. This gives a sufficient theoretical basis for thedesign of structure and performance of the pump.The pump head and pump valve are designed using AutoCAD and PRO/E softwareaccording to the performance parameters requirements of the pump. On the basis of theresearch of all kinds of load conditions subjected by pump head and pump valve, the finiteelement models are established for the finite element analysis.The static and fatigue strength analysis of pump head is carried using ANSYS. Thefatigue crack initiation life of pump head between autofrettage and un-autofrettage arecompared. The process of valve plate impacting the seats under a certain speed is analyzed byLS-DYNA module in ANSYS. Combined with the contact analysis in closed state, this paperfinds the main fault information of the valves for providing theoretical basis on the design and usage of valves.The plunger seal structure is studied and designed in this paper. The relationship betweenthe inlet pressure and gap size and the leakage is also simulated using large scale finitenumerical simulation software. The results show that the leakage will increase with theincrease of the inlet pressure and gap size and the tiny change of gap size can lead to largevariation of the leakage.