钻头干钻碎岩过程中的热传导理论分析与研究进展

Theoretical analysis and research progress of heat conduction in the dry drilling and rock breaking process of bits

摘要:

钻探技术是地球深部资源开发和月球勘探的核心手段，钻头在干钻等极端工况下的温度变化会导致钻头磨损加剧甚至失效，解析钻头温升机制对优化钻探工艺、延长钻头使用寿命至关重要。由于实验条件难以全面模拟复杂工况，且数值模型常因简化假设而受限，理论模型的构建成为揭示钻头温升规律的关键。本文首先以金属切削理论为基础，解析了切削力与切削热的生成机制，建立了钻头-岩石-岩屑系统的三维导热微分模型。在此基础上，从理论模型、受力分析、产热分析3个方面对比了硬质合金钻头与PDC钻头的温升机制，指出模型通过简化切削结构分离剪切热与摩擦热的有效性。相对而言，孕镶金刚石钻头的理论研究因金刚石颗粒的微切削特性、出刃高度动态变化及接触面积的不确定性而进展缓慢。为构建适应性更强的热力学模型，未来需利用多物理场耦合方法，并结合岩石特性、钻头材料属性和动态工况参数开展深入研究。

Abstract:

Drilling technology is pivotal in deep earth resource development and lunar exploration. The temperature fluctuations experienced by the bit under extreme working conditions such as dry drilling can lead to increased wear and potential failure of the bit. Therefore， analyzing the temperature rise mechanism is crucial for optimizing the drilling process and extending the life of the bit. Given the limitations of experimental methods in replicating extreme operational environments and the inherent simplifications in numerical simulations， constructing a theoretical model becomes essential to reveal the temperature rise behavior of the bit. This paper first analyzes the generation mechanisms of cutting force and cutting heat based on metal cutting theory， establishing a three-dimensional heat transfer differential model of the bit-rock-chip system. Subsequently， the temperature rise mechanisms of cemented carbide bits and PDC bits are compared from three perspectives： theoretical modeling， force analysis， and heat generation analysis. This comparison highlights the effectiveness of the model by simplifying the cutting structure and distinguishing between cutting and frictional heat. In contrast， the theoretical study of impregnated diamond bits has progressed more slowly due to the micro-cutting characteristics of diamond particles， dynamic changes in the height of the cutting edge， and uncertainties in the contact area. To develop a more adaptable thermodynamic model， future research should employ multi-physics coupling methods， incorporating rock properties， drill bit material properties， and dynamic operating parameters.