轴向旋转热管砂轮的传热性能研究

发布时间：2018-04-25 08:15

  本文选题：轴向旋转热管砂轮 + 枞树形　； 参考：《南京航空航天大学》2017年硕士论文

【摘要】：结合超硬磨料技术的发展与应用,成型磨削在航空难加工材料(如高温合金、钛合金等)加工中的优势愈来愈显著,尤其在加工难度较大的航空发动机涡轮盘榫槽的加工中,成型磨削的加工精度和表面质量都优于其他加工方式。然而,由于航空难加工材料粘附性强、导热性差等特点,使得成型磨削时磨削温度过高从而引起工件表面热损伤以及砂轮磨损,这势必制约了成型磨削技术优势的充分发挥。此前已有研究将径向旋转热管砂轮用于磨削弧区温度的控制,充分显示了“热管技术”用于难加工材料高效磨削中的可行性。有鉴于此,本文将轴向旋转热管引入成型砂轮的设计中,研制出了轴向旋转热管砂轮用于涡轮盘枞树形榫槽的成型加工,并开展了一系列传热性能试验,验证了轴向旋转热管砂轮用于难加工材料成型磨削中的可行性,探究了热管砂轮冷凝段冷却条件、充液量以及蒸发段热流密度等因素对轴向旋转热管砂轮传热性能的影响。研究成果对于解决成型磨削难加工材料时磨削温度过高的问题具有重要意义。本文完成的工作主要包括:(1)针对涡轮盘枞树形榫槽的加工要求,提出轴向旋转热管砂轮的设计方法,并依据此设计方法完成了可拆卸轴向旋转热管砂轮的设计及制作;(2)对结构较为简单的圆柱形轴向旋转热管砂轮进行传热性能分析,验证了其疏导弧区磨削热的可行性,分析得出了合适的冷凝段冷却条件和充液量。结果表明,充液量为热管体积15%且冷凝段采用6℃、85 m/s以上冷风射流冷却时能充分发挥轴向旋转热管砂轮的传热性能;(3)开展枞树形轴向旋转热管砂轮的传热性能试验,并结合热管砂轮蒸发段内腔的工质分布仿真结果,为枞树形轴向旋转热管砂轮充液量的选择和结构优化提供依据。鉴于枞树形轴向旋转热管砂轮内部结构的特殊性,工作介质在旋转状况下易集中在蒸发端偏上及绝热段的位置,因此为了更好地发挥热管的优势,相对于圆柱形轴向旋转热管砂轮,应将充液量提高一倍左右。
[Abstract]:Combined with the development and application of superhard abrasive technology, the advantages of molding grinding in the processing of aviation refractory materials (such as superalloy, titanium alloy, etc.) are becoming more and more obvious, especially in the machining of engine turbine disk tenon grooves, which are more difficult to process. The machining accuracy and surface quality of molding grinding are superior to other machining methods. However, due to the characteristics of high adhesion and poor thermal conductivity of aviation refractory materials, the high grinding temperature in molding grinding will cause thermal damage on workpiece surface and grinding wheel wear, which will restrict the full play of the advantages of molding grinding technology. Previous studies on the application of radial rotating heat pipe grinding wheel to the temperature control of grinding arc zone have fully demonstrated the feasibility of "heat pipe technology" in high efficiency grinding of refractory materials. In view of this, the axial rotating heat pipe is introduced into the design of the grinding wheel, and the axial rotating heat pipe grinding wheel is developed for the forming process of the fir tree tenon groove of the turbine disk, and a series of heat transfer performance tests have been carried out. The feasibility of axial rotating heat pipe grinding wheel used in forming grinding of refractory materials was verified. The effects of cooling conditions of condensing section of heat pipe wheel, liquid filling amount and heat flux of evaporation section on the heat transfer performance of axial rotating heat pipe grinding wheel were investigated. The research results are of great significance to solve the problem of high grinding temperature in forming grinding difficult materials. The work accomplished in this paper mainly includes: (1) according to the machining requirement of turbine disk fir tree tenon groove, the design method of axial rotating heat pipe grinding wheel is put forward. According to this design method, the design and manufacture of the detachable axial rotating heat pipe grinding wheel are completed. The heat transfer performance of the cylindrical axial rotating heat pipe grinding wheel with simple structure is analyzed, and the feasibility of grinding heat in the dredge arc zone is verified. The appropriate cooling conditions and liquid filling amount of the condensing section are obtained. The results show that the heat transfer performance of the fir tree axial rotating heat pipe wheel can be fully developed when the condensing section is cooled by cold air jet at 6 鈩，

本文编号：1800507