The Research On The Chamber Of1176kW Five-Cylinder Drilling Pump

Drilling pump, also called mud pump, is an important part of rig circulation system. Pressure pulsation, as inherent characteristic of crank-link drilling pump, is a primary factor of drilling accidents, about40%of them are caused by pressure pulsation. So reducing pressure pulsation, is not only beneficial to drilling accidents, but can significantly improve the properties of the pump as well. One method, at present widely used, in order to decrease the amplitude of pressure pulsation, is fixed an air accumulator on the discharge pipe, near outlet valve housing.The air chamber is an important component of hydraulic system of drilling pump. It keep flow steady and reduce pressure fluctuation, owing to the characteristics, that chamber volume shrink and expand with the pressure change, by absorbing (or releasing) part of liquid that over (or below) the average.The paper focus on the air chamber assembly of five-cylinder1176kW drilling pump, with large displacement and working pressure. Greatly through analyzing and researchhing, the author systematicly introduce and summarize the air-chamber design theory and method of five-cylinder drilling pump. In the opening chapter of this article, we firstly discuss the technical status and development tendency of the drilling pump, and illustrate the necessity of implementing this subject. Next step, we do some research on hydraulic characteristic of the five-cylinder drilling pump, based on kinematic analysis; Deduce the transient flow expression of the five-cylinder pump; Draw the instantaneous flow curve utilizing the Matlab software; Analyze the major factors caused flow pulsation. Thirdly, we analyze the dynamic characteristic of air chamber system in detail. Establishe mathematic model of the discharge system following air chamber; Draw the flow dynamic equation, and the dynamic equation of chamber volume and pressure, then test the equations by an instance. Fourthly, the author put forward a simple method to design air chamber. In a given conditions, we calculate and determine the chamber(dome) volume and inner diameter of the1176kW five-cylinder drilling pump by this method. Further, we calculate parameters of other parts of the air chamber assembly, set up their3D models using Pro/E software. Finally, unlike traditional design approach, the author introduce FEM(finite element method) into the air chamber design, building parts model using Pro/E software, and doing finite element analysis by Ansys software, lastly check it according to the ASME standard. Results show that the design is fully comply with the ASME standards, and meet the requirements. Doing this research is greatly helpful to reduce system vibration, lower noise, and improve working property and service life of the drilling pump.