热力耦合作用下修井磨鞋产热规律与控温方法

Heat production law and temperature control method of milling tools for workover under action of thermo-mechanical coupling

针对修井液冷却不充分恶劣工况下修井磨鞋钻进慢、磨损快的技术瓶颈问题,基于热源法原理和傅里叶定律建立修井磨鞋磨粒力学与温度解析模型,明确磨粒受力、温度与结构参数的定量关系,采用温度-位移耦合侵彻接触算法建立磨粒热力耦合仿真模型,结合全尺寸修井磨鞋无冷却钻进试验探究室温环境下的修井磨鞋产热规律,进而提出改善修井磨鞋散热特性的控温方法,同时开发新型修井磨鞋并验证实际散热效果。结果表明:修井磨鞋磨粒的高温区域分布在磨粒切削刃和前刀面,高温中心由磨粒刀尖向前刀面逐渐演化,最高温度达到612.3℃;从磨粒切削刃、磨粒后角、水眼布置和散热方式等方面提出修井磨鞋控温方法,有散热孔磨粒稳定阶段的降温幅度在13.9%~21.3%;相对于常规修井磨鞋,新型修井磨鞋的高温区域由磨粒工作表面转移到试验工件表面,室温环境下的降温幅度超过10.5%。

In order to solve the technical bottlenecks of slow footage and fast wear of milling tools for workover under the harsh conditions of inadequate cooling of workover fluid,an analytical model of mechanics and temperature of milling tools for workover was established based on the principle of heat source method and Fourier s law.The quantitative relationship among the force,temperature and structural parameters of milling tools for workover was clarified.Meanwhile,a thermo-mechanical simulation model of milling tools for workover was built by using a temperature-displacement coupled intrusion contact algorithm.In addition,a full sized milling tool for workover was developed and the actual cooling effect was verified in a room-temperature environment.Then the temperature control method to improve the heat dissipation characteristics of milling tools for workover was proposed.The new typed milling tools for workover were developed to verify the actual effect of heat dissipation.The results show that the high-temperature area of the milling tool for workover is distributed in the cutting edge and front face of the abrasive grain,and the high-temperature center evolves gradually from the tip to the front face of the abrasive grain,where the highest temperature can reach 612.3℃.The temperature control method is proposed in terms of the cutting edge of the abrasive grain,the back angle of the abrasive grain,the arrangement of water eyes and the way of heat dissipation.The temperature reduction range of the abrasive grain with heat dissipation holes is between 13.9%and 21.3%.Compared to conventional milling tools for workover,the high-temperature area of the improved milling tool for workover is transferred from the abrasive grain surface to the experimental workpiece surface,and the temperature reduction range of the improved milling tool for workover is more than 10.5%in a room-temperature environment.