Reserch On The Hydraulic System And Control Of Power Unit Of Large Scale Horizontal Directional Drilling

With the steady progress of the rapid development of our economy and urbanizationconstruction, repair, replacement and construction of underground pipelines is essential.Because of the enormous economic and social development of energy consumption,petroleum, natural gas, coal gas pipeline laying projects has become an important part ofChina’s energy strategy. These provide a favorable market conditions for the developmentof trenchless technology. And the construction of oil, natural gas pipelines and other largepipeline projects would require large scale horizontal directional drilling as a support, itsdomestic market demand is very impressive. Therefore, it is necessary to carry out largescale horizontal directional drilling research and development. The hydraulic system andcontrol system of power unit as the most critical part of the drilling, which determine thelevel of quality of the drilling.This thesis analyzes and compares pump control closed-circuit hydraulic system andpump control open-circuit hydraulic system, also introduces characteristics and structureof distributed control system based on CAN-bus. These provide the theoretical basis forthe hydraulic system and control of power unit.On the basis of analysis of the rig construction technology and features, proposes thedesign requirement of power unit hydraulic system. According to the principle of maincomponents of the hydraulic system, derives the mathematical models for hydraulic pumpand hydraulic motor. Mathematical models are used to analyze the dynamic characteristicsof the hydraulic system. Thesis builds the simulation models for hydraulic pump andpower unit hydraulic system and gives the experimental verification. Simulation resultsshow the influence of different parameters on the system dynamics, these provide the basisfor system debugging and improving.Thesis analyzes the structure of power unit control system, designs the controlfunction, and describes main hardware of the system. On the basis of the control systemarchitecture, propose automatic engine deceleration control, also analyze the application ofthe automatic deceleration control, design the control functions, and determine some of the control parameters. These have important implications for the drilling’s energyefficiency.Build the experimental platform and do the experiment to test and verify thesimulation models.