scholarly journals Heat Transfer Performance of an Axially Rotating Heat Pipe for Cooling of Grinding

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5745
Author(s):  
Jiajia Chen ◽  
Huafei Jiang ◽  
Yucan Fu ◽  
Ning Qian
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Rotational Speed ◽  
Heat Transfer Performance ◽  
Simulation Method ◽  
Filling Ratio ◽  
Grinding Wheel ◽  
Good Prospect ◽  
Transfer Performance

Coolants are widely used to dissipate grinding heat in conventional grinding. This process, however, is not satisfactory as coolants often lose efficacy in grinding due to film boiling and can result in adverse health and environment effects. The present paper put forward the concept of a rotating heat pipe grinding wheel, attempting to reduce or eliminate the coolant amount and realize green machining. The heat transfer performance of rotating heat pipe grinding wheel was studied by using volume of fluid method in ANSYS/FLUENT. The influence of the input heat flux, filling ratio and rotational speed were investigated by a simulation method. Results show that the appropriate heat flux range for the rotating heat pipe grinding wheel was from 2000 to 100,000 W/m2, the ideal filling ratio was 50% and the rise of the rotational speed turned out to weaken the heat transfer coefficient. Finally, dry grinding experiments on Ti-6Al-4V were performed and the temperatures in both the rotating heat pipe and the grinding contact zone were monitored. The new designed rotating heat pipe grinding wheel showed a good prospect for application to green grinding of difficult-to-cut materials.

Investigation on Heat Transfer Performance of Heat Pipe Grinding Wheel in Dry Grinding

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Qingshan He ◽  
Yucan Fu ◽  
Jiajia Chen ◽  
Wei Zhang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Transfer Performance ◽  
Equivalent Thermal Conductivity ◽  
Dry Grinding ◽  
Pipe Heat

The use of fluid in grinding enhances heat exchange at the contact zone and reduces grinding temperature. However, the massive use of fluid can cause negative influences on environment and machining cost. In this paper, a novel method of reducing grinding temperature based on heat pipe technology is proposed. One new heat pipe grinding wheel and its heat transfer principle are briefly introduced. A heat transfer mathematical model is established to calculate equivalent thermal conductivity of heat pipe grinding wheel. Compared with the wheel without heat pipe, heat transfer effect of heat pipe grinding wheel is presented, and the influences of heat flux input, cooling condition, wheel speed, and liquid film thickness on heat transfer performance are investigated. Furthermore, dry grinding experiments with two different wheels are conducted to verify the cooling effectiveness on grinding temperature. The results show that thermal conductivity of the wheel with heat pipe can be greatly improved compared to the one without heat pipe; heat transfer performance of heat pipe grinding wheel can change with different grinding conditions; meanwhile, grinding temperatures can be significantly decreased by 50% in dry grinding compared with the wheel without heat pipe.

Working Fluid Inventory Effect on Heat Transfer Performance of a Grooved Micro Heat Pipe

2013 ◽  
Vol 589-590 ◽  
pp. 559-564
Author(s):  
Xi Bing Li ◽  
Yun Shi Ma ◽  
Xun Wang ◽  
Ming Li
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Mathematic Model ◽  
High Heat ◽  
Working Fluid ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Flux Concentration

As a highly efficient heat transfer component, a micro heat pipe (MHP) has been widely applied to the situations with high heat flux concentration. However, a MHPs heat transfer performance is affected by many factors, among which, working fluid inventory has great influence on the security, reliability and frost resistance of its heat transfer performance. In order to determine the appropriate working fluid inventory for grooved MHPs, this paper first analyzed the working principle, major heat transfer limits and heat flux distribution law of grooved MHPs in electronic chips with high heat flux concentration, then established a mathematic model for the working fluid inventory in grooved MHPs. Finally, with distilled water being the working fluid, a series of experimental investigations were conducted at different temperatures to test the heat transfer performances of grooved MHPs, which were perfused with different inventories and with different adiabatic section lengths. The experimental results show that when the value of α is roughly within 0.40±0.05, a grooved MHP can acquire its best heat transfer performance, and the working fluid inventory can be determined by the proposed mathematic model. Therefore this study solves the complicated problem of determining appropriate working fluid inventory for grooved MHPs.

Effect of Processing Parameters on Heat Transfer Performance of the Heat-Pipe Grinding Wheel

2012 ◽  
Vol 217-219 ◽  
pp. 2480-2483
Author(s):  
Ke Ma ◽  
Yu Can Fu ◽  
Hong Jun Xu ◽  
Jun He
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Processing Parameters ◽  
Grinding Wheel ◽  
Transfer Performance ◽  
Filling Rate ◽  
Great Role ◽  
Transfer Experiment ◽  
Rotating Speed

Heat transfer performance of the heat-pipe grinding wheel (HPGW) is mainly depended on the heat pipe in the wheel. In this paper, a basal body of HPGW was developed and a heat transfer experiment was performed to study the effect of the parameters of the heat pipe such as liquid filling ratio and rotating speed on the heat transfer performance of the HPGW. Results show that the heat transfer performance decreases if the liquid filling rate is too large or too small under the same heat source intensity and the optimal liquid filling rate is about 35% of the volume inside the heat pipe. The heat transfer performance of the HPGW is enhanced with the increasing of the rotating speed. The analysis of the results also shows that the heat pipe in the HPGW can play a great role on enhancing the heat transfer in the grinding zone with suitable processing parameters.

scholarly journals Experimental Study of the Heat-Transfer Performance of an Extra-Long Gravity-Assisted Heat Pipe Aiming at Geothermal Heat Exploitation

2021 ◽  
Vol 13 (22) ◽  
pp. 12481
Author(s):  
Jiwen Cen ◽  
Feng Li ◽  
Tingliang Li ◽  
Wenbo Huang ◽  
Juanwen Chen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Filling Ratio ◽  
Working Fluid ◽  
Enhanced Geothermal Systems ◽  
Transfer Performance ◽  
Cooling Water Flow Rate

The installation and operation of enhanced geothermal systems (EGS) involves many challenges. These challenges include the high cost and high risk associated with the investment capital, potential large working-fluid leakage, corrosion of equipment, and subsiding land. A super-long heat pipe can be used for geothermal exploitation to avoid these problems. In this paper, a high aspect-ratio heat pipe (30 m long, 17 mm in inner diameter) is installed vertically. Experiments are then carried out to study its heat-transfer performance and characteristics using several filling ratios of deionized water, different heating powers, and various cooling-water flowrates. The results show that the optimal filling-ratio is about 40% of the volume of the vaporizing section of the heat pipe. Compared with a conventional short heat pipe, the extra-long heat pipe experiences significant thermal vibration. The oscillation frequency depends on the heating power and working-fluid filling ratio. With increasing cooling-water flow rate, the heat-transfer rate of the heat pipe increases before it reaches a plateau. In addition, we investigate the heat-transfer performance of the heat pipe for an extreme working-fluid filling ratio; the results indicate that the lower part of the heat pipe is filled with vapor, which reduces the heat-transfer to the top part. Based on the experimental data, guidelines for designing a heat pipe that can be really used for the exploitation of earth-deep geothermal energy are analyzed.

Heat Transfer Characteristics of Oscillating Heat Pipe With Water and Ethanol as Working Fluids

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Haizhen Xian ◽  
Yongping Yang ◽  
Dengying Liu ◽  
Xiaoze Du
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Inclination Angle ◽  
Heat Transfer Performance ◽  
Filling Ratio ◽  
Working Fluid ◽  
Transfer Performance ◽  
Heat Transfer Characteristics ◽  
Oscillating Heat Pipe ◽  
Transfer Characteristics

In this paper, experiments were conducted to achieve a better understanding of the oscillating heat pipe (OHP) operating behavior with water and ethanol as working fluid. The experimental results showed that there existed a necessary temperature difference between the evaporator and the condenser section to keep the heat pipe working. The maximum effective conductivity of the water OHP reached up to 259 kW/m K, while that of the ethanol OHP is of 111 kW/m K. Not all the OHPs are operated in the horizontal operation mode. The heat transfer performance of the ethanol OHP was obviously affected by the filling ratio and the inclination angle but the influence law is irregular. The effect of the filling ratio and the inclination angle of the water OHP were smaller than that of the ethanol one. The heat transfer performance of the OHP was improved with increase of operating temperature. The startup characteristics of the OHP depended on the establishment of the integral oscillating process, which was determined by the operating factors. The startup temperature of the ethanol OHP varied from 40°C to 50°C and that of the water, OHP varied from 40°C to 60°C without considering the horizontal operating mode. The water OHP showed a better performance and more stable heat transfer characteristics than the ethanol OHP, which had no obvious advantages of the startup capability as well.

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