The Structure Design And Simulation Research Of Large Flow Directional Control Valve For Full Hydraulic Fracturing Truck

As the energy demand is increasing, the development of unconventional oil and gas resources is more and more important. As a result of the traditional mechanical fracturing truck with short life and high cost, a company design a kind of hydraulic fracturing truck based on full hydraulic transmission. Full hydraulic fracturing truck isdesigned with the driving way, which use the engine, oil pump, reversing valve group,oil cylinder, pressure cylinder and flat valve, it effectively reduces the complexity of the structure and cost savings. However, the reversing valve with high pressure an large flow rate is needed to meet the full hydraulic fracturing truck reversing. At present, the valve to satisfy the requirement of reversing mainly is the cartridge and slide valve type, while reversing valve of cartridge type has compact structure and small size, but the large size cartridge valve to satisfy the requirement of large flow rate is expensive and the demand is bigger, the slide type valve is basically rely on imports. Therefore, designing and researching the reversing valve with high pressure and high flow rate, not only can satisfy the requirement of the hydraulic system of hydraulic fracturing truck reversing, but also give great importance to improve the level of directional valve technology and research in China.In this thesis, the author studied high flow directional control valve to meet therequirements of the hydraulic system of the full hydraulic fracturing truck reversing through simulating and experimenting, the structure design and test simulation is carried, the improved design is conducted based on the results of the experiment and simulation. First, according to the working principle of the directional control valve, the design process of main parts is explained in detail, the stress of the directional control valve is analyzed, the main stress of the reversing valve was calculated, and the pressure loss of main valve is analyzed and checked. The calculation procedures of the chute valve was established based on the MATLABto simplify the calculation of valve port flow area; Then the dynamics and flow characteristic equation of directional control valve is established, providing a basis for the establishment of the reversing valve simulation model; The simulation model of directional valve was established by AMESim, the influence of the pilot pressure, the guide flow to the characteristics of the main valve’s opens is analyzed importantly, and the influence of other structure on the properties of the reversing valve is analyzed; Comparing with the test results, the existing problems in the reversing valve in design is obtained, which made the improvement measures; The big flow directional valve structure to meet requirements is reachedby improving the valve structure of spring seat, control end, as well as the simulationanalysis of the improved structure.