Research Of Deep Hole Drilling Cutting Fluid Cooling System Based On Heat Transfer Enhancement

Deep-hole drilling produces a lot of heat. The cutting fluid is used to cool and lubricatethe deep-hole tool, in addition, it can transport chips. In the process of circulating cooling, thetemperature of cutting fluid rises, which affects the cooling effect and processing quality.However, the above problem is often neglected. There are less relevant design theories andprograms which solves the problem. Therefore, it is necessary to study the deep-hole cuttingfluid high efficient cooling system, which ensures that the process of deep-hole drilling issmooth.Firstly, this paper introduces the advantages and disadvantages of traditional cutting fluidcooler. For the widely used shell and tube cooler, the paper analyzes the shell fluid flowcharacteristics and heat transfer effect, and proposes the enhancement direction of heattransfer. Secondly, for the heat transfer enhancement direction of traditional cooler, a kind ofheat transfer tubes with bi-directional spiral oval structure is proposed. By using Boundarylayer theory and Field synergy theory respectively, the fluid of the inside and outside ofbi-directional spiral oval tube is analyzed. In addition, the enhanced heat transfer mechanismis studied. The analysis shows that the secondary flow of a bi-directional spiral oval tubeenhances the heat transfer of fluid. Otherwise, the vertical vortex outside tube also enhancesheat transfer. The analysis above provides reference for the improvement of efficient andcooler. For the deep-hole drilling of T2120machine tool, this paper designs a cutting fluidmagnetic filtration device, whose structure is simple and cleansing operation is easy. Thepaper takes an example, which is that the20℃water cools the temperature of cutting fluidfrom55℃to35℃, and then the heat output of cutting fluid is calculated. Based on the abovecalculation, the design of bi-directional spiral oval tube spiral oval tube cooler is completed.Finally, the control system of cutting fluid temperature and the online monitoring system of cooler are designed. By controlling the flow rate of the cooling water, the temperature of thecutting fluid is controlled. By monitoring the information of real-time flow, temperature andpressure of cooling water and cutting fluid, the running state of the cooler can be got.Meanwhile, by using the Fluent software, the paper analyses flow condition of fluid ofbi-directional spiral oval tube cooler in shell side and in tube side. When the fluid flows, theresult shows that the fluid in tube side and in shell side have disturbance in varyingdegrees. Due to the generation of secondary flow, the fluid appears radial velocity componentin the process of fluid flow, which reduces the thickness of the wall thermal boundary layer, inaddition, the synergy degree of fluid velocity field and temperature gradient field isstrengthened, thus the heat transfer is reinforced.