Application Research Of Phase Change Materials In Logging Tool

Under the increasingly severe background of the global energy crisis,it is imperative to increase the extraction rate of our country’s petroleum resources and increase the reserves of petroleum resources.Logging tool is the core equipment in the field of petroleum exploration,the thermal failure of its internal electronic components in extreme environments is the key to restricting the development of logging tool.Phase change materials are used in logging tool due to their extremely strong heat storage capacity and the special properties of constant temperature during phase change process.At the same time,when phase change materials are used as thermal storage module in logging tool,they often face leakage problems.Different phase change materials have different temperature control capabilities for electronic devices.How to select suitable phase change materials to achieve a better temperature control effect is an urgent problem to be solved.Based on this,this thesis has launched some research on phase change materials in logging tool.The appropriate packaging technology was selected and a high-temperature vibration test bench was built to complete the high-temperature vibration test.After comparing two packaging technology,we chose the better one to use.Subsequently,paraffin wax and Wood’s alloy were used as thermal storage module to have high-temperature leakage test and hightemperature vibration test at 200℃ for 6 hours.The result indicates that the module package has good reliability.The thermal management application of paraffin wax and Wood’s alloy in logging tool through simulation and experiment methods was discussed.The simulation result indicated that the circuit board average temperature of the logging tool with Wood alloy was 21.26℃lower than that of the paraffin group.Subsequently,the packaging technology in Chapter 3was applied to the logging tool model prototype,and a high-temperature heating experiment was carried out with paraffin wax and Wood’s alloy as endothermic agents.The experiment result indicated that the circuit board average temperature of the Wood alloy group was 25℃lower than that of the paraffin group and the temperature control effect of Wood’s alloy was better than that of paraffin wax.Then we made the error analysis between simulation and the experiment,the average error between the simulation and experiment was 3.59% in paraffin group and the average error in the Wood alloy group was 7.85%.The result indicates that the accuracy of finite element analysis is high and the simulation results are credible.The method that neural network combined with the mean impact value method was used to study the selection of phase change materials in the logging tool.From the perspective of the limited internal space of the logging tool,the specific heat capacity and phase change latent heat of the phase change material were converted into volume specific heat capacity and volume phase change latent heat.After verifying the accuracy of the finite element analysis,we used finite simulation to get the original data set.The neural network model architecture and parameters are finally determined through training set training.Then combined with the mean impact value method,the order of factors affecting the temperature control ability of the thermal storage module of the logging tool is: volumetric specific heat capacity→thermal conductivity→volume latent heat→melting point,and then we make a physical explanation of each influencing factor.Finally,we use different phase materials to verify the accuracy of the conclusion and give some suggestions on the selection of phase change materials.