Research On Heat Dissipation Performance Of Bionic Impregnated Diamond Bit

Impregnated diamond bit is the main tool of crushing rock，widely used in the field of hardrock drilling. Due to the world demand for oil and gas resources presents a linear upward trend，explorers naturally aim at the Earth’s deep resources. Researchers of Jilin University developedbionic impregnated diamond bit. Its drilling efficiency is increased by at least30%compared withordinary one，bit life by30%，and the power consumption can reduced by40%as well. However,the impact of bionic non-smooth structure on the thermal performance of the bit has not beenthoroughly studied. Researching on bionic impregnated diamond bit thermal performance hasimportant significance for in-depth study of the abrasion mechanism.This paper explores the influence of the bionic unit body and bionic units body configuration onthe flow field，temperature field and temperature distribution in the solid domain using thenumerical simulation and experiments. The main work is as follows:In order to achieve the purpose of real-time measurement of the temperature in the drillingprocess, we designed and made the testing rig which can test real-time temperature. The test rig iscomposed of feeding system, cooling system, temperature testing systems and workbench. Feedingsystem includes pneumatic pump, pneumatic cylinder, directional control valve, cylinder liner,drill pipe and drill bit. Revolving system includes electric motor, belt pulley, strap, gripper andconnecting shaft. Cooling system includes pressure water tank, water regulating valve and chipbox. Temperature testing system includes thermal couples, temperature sensor, data acquisitionline and intelligent acquisition module. Workbench includes base, box, drainage plate, water baffle,lug boss and reinforcing rib. The test rig can correctly reflect the working conditions, preciselycontrol the parameters as well.At the same conditions, the temperatures in the depths of the sink hole12mm and6mm onthe matrix of different bits were obtained using thermal couples test. the experimental results showthat the temperature of ordinary bit, bionic bit-1540, bionic bit-2035，bionic bit-2025，bionic bit-2040，bionic bit-1525，the bionic bit-1535decreases by their turns. In the depth of the sinkhole12mm, the bionic bit, compared with the ordinary bit, reduces the temperature in the range of4.6%to19.8%. In the depth of the sink hole6mm, the bionic bit reduces the temperature in therange of4.9%to16.2%. The results of heat-fluid-solid coupling numerical simulation indicatethat the temperature distribution of the bionic bit is lower than the ordinary bit. The temperaturedifference of bionic bit and ordinary bit is most evident in the concave pit. The maximumtemperature difference and the minimum temperature are104.4℃and44.7℃respectively. Thebionic bit, compared with the ordinary bit, reduces the temperature in the range of6.1%to14.2%Numerical simulations were used to carry on the comparative study of flow field andtemperature field of fluid domain of the bionic and smooth impregnated diamond bit. Using heat-fluid-solid coupling method, the influence of the bionic unit body and bionic units bodyconfiguration on temperature distribution in the solid domain was explored. According to the testand simulation results，the heat dissipation mechanism of bionic impregnated diamond bit can beconcluded as follows: the concave pit reduces the area of the frictional contact，which results inreduction of the heat; thick film of water inside the pit has large thermal resistance, and blocksheat transfer, which will inevitably lead to lower the temperature around the concave pit;the perturbation of concave pit on cooling fluid can be able to enhance the heat transfer betweencooling fluid and exploration bit, take much heat away and reduce the transfer of heat to the interiorof the bit. The proportion of the circumferential distance DAand the radial distance DRof thebionic unit body has significant effects of heat exchange between cooling fluid and exploration bit.The proportion of the circumferential distance DAand radial distance DRis about1：2will obtaingood heat dissipation effect.