Reseach On The Matching Of Engine And Hydrodynamic Torque Converter Of Fracturing Truck

Fracturing truck is the core equipment in oilfield fracturing operations. With increasing depth,the development of oil and gas wells becomes more and more difficult. The maximum working pressure required for fracturing operations was increasing, which put forward higher requirements of power performance of the fracturing truck. At present, fracturing truck power system designed by the domestic manufacturers usually use foreign engine and hydraulic torque converter, the model combination was given by the foreign company directly. Which lead to the domestic enterprises knowing little about the specific dynamic matching process, and have a great impact on the independent research and production of fracturing truck and related equipment. In this paper,we take the 2500 fracturing truck as object, reaserch the application of power matching theory in the design of fracturing truck station power system. The main contents are as follows:(1) Overall design of the power system. According to the work features of power system,three transmission schemes were proposed. And a comparative analysis wrer made to determine the final transmission scheme; researched the technology of engine and torque converter selection, made the selection criteria and complete the selection of engine and torque converter.(2) Design and calculation of the matching performance between engine and torque converter.Test data of engine speed characteristic and torque converter original characteristic were obtained, as well as curves of the engine external characteristics and torque converter original characteristics. Researched on the matching principle between engine and torque converter, selected a appropriate matching principle to identified the effective diameter of the torque converter cycle.Introduced the concept of lock-point, and the lockup clutch speed ratio was choiced as the parameter of controlling. Based on the designed parameters, characteristics of the cooperation between engine and torque converter were calculated,which include common input characteristics, output characteristics and working characteristics of the fracturing pump.(3) Optimization of the matching performance between engine and torque converter. Using least-square theory, models of the engine full load characteristic and torque converter original characteristic were established,as well as the mathematical model of calculating process of matching performance. Build the evaluation system of matching performance between engine and torque converter, gave the definition and of each index. Using AHP, the relative weight of each index were determined. Taking the effective diameter of the hydraulic torque converter and lockup rotating speed ratio as design variables, build the optimization model of the matching performance. After optimization,the matching performance has been greatly improved.(4) Development of the power-matching program. Considering the large amount of calculation in the process of power matching,a easely used program was developed using the mixed programming technology of VB and MATLAB. Which can significantly reduce the repetitive work of designers, and improve their work efficiency.