Failure Analysis and Equal Life Optimization Design of Fluid End of Electric Fracturing Pump.

In view of the failure phenomenon that the 4 inch T type structure stainless steel fluid end of the electric fracturing pump suffers many fatigue cracks in the cross-bore area, and the damage life between each cylinder and different areas within the cylinder is not uniform, which leads to the short fatigue life of the fluid end. To find out the failure causes and extend the fatigue life, the fluid end is optimized based on the concept of equal life. Firstly, according to the working conditions of the fluid end, the static analysis of the cylinder under 10 rated working conditions and one pressure test condition is carried out. The calculated results all meet the static strength requirements. Secondly, based on the static finite element analysis results of 10 kinds of actual working conditions, the cyclic peaks were found through the constant amplitude alternating load, and the fatigue life and distribution law of the fluid end were calculated. Then, by comparing with the damage data summarized in the field construction, it is found that the calculated fatigue life and distribution area of the fluid end are in good agreement with the actual damage life and the overall situation of the area. Finally, by increasing the single-side margin e to 80 mm, the fatigue life of cylinders 1 and 5 is extended by 66.4%, and the fatigue life of fluid end is extended by 58.7%. The fatigue life of fluid end is increased by 7.9% through orthogonal optimization of the intersecting line fillet radius R1 is 15 mm, the bottom fillet radius R2 is 12 mm, and the cutting depth of arc groove D is 230 mm. The fluid end fatigue life is extended by 71.3% total. The results show that the fluid end fatigue life analysis method by finding the cycle peak can be used to calculate the fluid end fatigue life accurately. The equal life parameter optimization method combining single factor and orthogonal test is of reference significance for the optimization of fluid end structural parameters and the extension of fluid end fatigue life of other types of fracturing pumps. [ABSTRACT FROM AUTHOR]