Research On Magnetic Suspension Underground Power Generation Device

At present,in order to improve the oil recovery rate of the oilfield,stratified water injection from water injection wells to oil layers is realized.Before water injection,it is necessary to obtain the working condition data of downhole oil layer with the help of downhole electric tools,and then determine the amount of water injection.However,how to supply reasonable power for downhole electric tools is a difficult problem to be improved.At present,the most commonly used power supply method is to put the battery pack,but this method needs to replace the battery regularly by taking wells,and there is also the risk of battery pollution.Another way of power supply is cable power supply,but most of the water injection wells around no power supply,need elevated or cable power transmission,increase the cost of oil exploitation.In the process of measuring while drilling,mud turbine generator is used to supply power for downhole tools,but this method is suitable for large flow of liquid medium and large underground space.Therefore,based on the research of previous scholars,this paper designs a set of magnetic suspension underground power generation device.In view of the above problems,this paper designs the initial structure of the device based on the principles of hydraulic machinery and computational fluid dynamics.Then,the CFD simulation software was used to simulate and analyze the structural flow field,and the structural optimization of the device was completed by combining the orthogonal experimental design and response surface analysis.Secondly,the power generation module is designed to complete the conversion and application of electric energy to ensure the normal charging of underground storage batteries.Finally,the power generation capacity of the magnetic levitation downhole power generation device is evaluated by simulation experiments.The research results show that the structure of magnetic suspension underground power generation device with high hydraulic performance is optimized by orthogonal experimental design and response surface analysis.The obvious and indigenous structural parameters are as follows:the angle of the first rotor blade is 90°,the inlet diameter is 5 mm,the height of the second rotor blade is 12 mm,and the layer spacing of the second rotor blade is 15 mm.The relationship between the obvious indigenous influence structural parameters and the rotational speed of the device rotor was also obtained.By analyzing the relationship between the operating parameters and the rotating speed of the rotating body,it is concluded that in the range of 5m³/d-25m³/d,the axial force of the rotating body in the device is 7N-127N,and the axial support force of the magnetic pole pair is 8.435N-128.435N;The interaction between the two-stage rotors was analyzed by changing different loads,and it was determined that the two-stage rotor promoted the first-stage rotor when the load was greater than 2.5×10^-3N·m,reflecting the good hydraulic performance of the device.According to the data measured by simulation experiment,when the resistance is 200Ω,the maximum power generation of the device is 447.46 m W.Under this condition,the lithium battery with 900 m Ah capacity of 3.7 V rated voltage can be charged for 7.4 h to fill the battery.