Thermodynamic aspects of heat pipe operation

Engineering Design Elements of a Two-Phase Thermosyphon to Trannsfer NGNP Nuclear Thermal Energy to a Hydrogen Plant

“…Close inspection of the vaporization line shows the slope of the P-T curve (dP/dT) increasing with temperature, indicating that the same temperature difference can provide a larger ǻP (more pumping power) if the thermosyphon is operating at a higher temperature. The same conclusion has been drawn by Richter and Gottschild (1994) for heat pipe operation. Additionally, with a higher operating temperature (increase in temperature) the liquid viscosity reduces and causes a higher flooding limit.…”

Feasibility and Effectiveness of Heat Pipe Cooling in End Milling Operations: Thermal, Structural Static, and Dynamic Analyses: A New Approach

“…To extend tool life, the most common approach is the use of cutting fluids flooding through the cutting zone. However, using cutting fluids often induce significantly negative Impacts on environment, safety, operators' health and operating cost and especially the use of water-based cutting fiuids in end milling operations usually increases temperature variation and, hence, thermal cracks [2,4,5], Heat pipe cooling is considered to be an effective alternative to conventional methods for removing heat from a tool tip, allowing machining operations to be implemented in a dry and "green" fashion [6][7][8][9][10][11][12], In this paper, the feasibility and effectiveness of heat pipe cooling in end milling operations are investigated. The thermal, structural static, and dynamic characteristics of the end-mill are predicted using a numerical calculation with fast finite element plus solvers based on explicit finite element analysis software, 2 FEA Model 2.1 Model Geometry.…”

Numerical Analyses to Investigate the Feasibility and Effectiveness in Using Heat Pipe Embedded End Mills

“…Judd et al [7] investigated turning of steel with a heat pipe embedded in a tool holder and reported that the heat pipe is found effective in reducing the tool-holder temperature by 30%. Chiou et al [8] and [9] conducted a finite element analysis and an experimental study of heatpipe cooling in steel machining using carbide tools. The authors concluded that the heat pipe, embedded in a cutting insert, is able to alleviate the cutting tool temperatures, reduce tool wear, and prolong the tool life.…”