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This study investigated the use of sintered Nickel powder as the wick material of Loop heat pipe with flat evaporator (Flat loop heat pipe, FLHP) and its effect on the heat transfer performance. Add the 1-heptanol into water and form Self-rewetting Fluid (SRF), resulting in the Marangoni effect. The colder liquid can be transport to the heating surface, delaying the occurrence of dry-out and increasing the critical heat load. This paper use Surface tension measurements to measure the change of 1-heptanol SRF, then it was apply to nickel wick FLHP as working fluid to investigate its effect on the heat transfer performance. This study successfully established production process of Nickel wick structure. Results of wick structure for the effective pore radius of 2.6 μm, porosity of 62%, permeability of 5.7 × 10-13m2. Results of Surface tension measurements show that 1-heptanol aqueous solution’s surface tension increases with increasing temperature, Results from applying 0.1% 1-heptanol aqueous solution to FLHP as working fluid. For performance testing show that the critical heat load was 240 W and the total thermal resistance was 0.77 ° C/W. Compared with FLHP with pure water, SRF raised the maximum heat flux of 70%, the total thermal resistance of the system reduces 40%, SRF has the potential to enhance the heat transfer performance of FLHP.

This study investigates the application of PTFE wicks to flat-plate loop heat pipes (FLHPs). PTFE’s low heat transfer coefficient effectively prevents heat-leakage, which is a problem with using metal wicks, lowering the operating temperature and pressure. This paper uses PTFE particles to form wicks, and the effect of PTFE on flat-plate LHP performance is investigated. Experimental results shows that the highest heat load reached was 100W, with lowest thermal resistance of 0.61°C/W, and heat flux of about 10W/cm2, For the wick properties, the wick had an effective pore radius of the wick was around 9.2μm, porosity of 47%, and permeability of 1.0 x 10-12m2. Compared to the highest heat flux reported in literature thus far for PTFE flat-plate LHPs, the heat flux in this study was enhanced by around 50%.

This paper specifically addresses the effect of the sintering temperature curve in manufacturing nickel powder capillary structure (wick) for a loop heat pipe (LHP) with flat evaporator. The sintering temperature curve is composed of three regions: a region of increasing temperature, a region of constant temperature, and a region of decreasing temperature. The most important region is the increasing temperature region, as the rate of temperature increase directly affects the performance of the wick.When the slope of the region of increasing temperature is 0.8 (equivalent to 8OC/min), the structure of the manufactured wick is complete, with the best heat transfer performance result. Experimental resultsshowed that the optimal heat transfer performance is 160W, the minimal total thermal resistance is approximately 0.43OC/W, and the heat flux is 17W/cm2; the optimal wick manufactured has an effective pore radius of 5.2 μm, a permeability of 5.9×10-13m2, and a porosity of 64%.

This study investigated the use of nanoscale bilayers assembly for hydrophobic surface modification on stainless steel plate and its effect on condensation. This study first performed nanoscale bilayers assembly method, with the addition of a fluorosilane treatment using chemical vapor deposition (CVD), to modify the surface structure and thereby the wettability of the surface at 15, 20, and 30 bilayers. Experimental results showed 15 bilayers to be the optimal number of bilayers among the samples tested, resulting in the largest contact angle of 150° (compared to 70° on unmodified surface), corresponding to the highest surface hydrophilicity; however, beyond 15 bilayers there seems to be no significant changes or improvements to hydrophobicity. Visualization of the condensation process also indicated later formation of film condensation on superhydrophobic (15 bilayers) surface, and by tilting the condensation surfaces at 90°, the self-cleaning property of the superhydrophobic surface allows water droplets to roll off the surface due to gravity before formation of film condensation, while large water droplets still remain stuck on unmodified surface. Therefore, by allowing the condensation process on the superhydrophobic surface to continuously cycle back to droplet condensation, there is great potential for condensation enhancement on superhydrophobically modified surface.

This study investigated the use of nanoscale bilayers assembly for hydrophilic surface modification on stainless steel plate. This study first performed nanoscale bilayers assembly method, with the addition of top layer coatings for durability purposes, to modify the surface structure and thereby the hydrophilicity of the surface at 15, 17, 20, 23, and 25 bilayers. The relationship between the number of bilayers and the resulting contact angle was then empirically established. Results showed 17 bilayers to be the optimal number of bilayers among the samples tested, resulting in the smallest contact angle of 11° (compared to 70° on unmodified surface), corresponding to the highest surface wettability and hydrophilicity. From 0 to 17 bilayers, the contact angle seems to decrease linearly with the number of bilayers. Beyond 17 bilayers, at 20, 23, 25, and 30 bilayers, the samples showed no significant improvements in contact angle or hydrophilicity.

This investigation concerned the photocatalytic decomposition of cis-dichloroethylene (cis-DCE) with titanium dioxide under irradiation of 365 nm wavelength UV light. The feasibility studies involved initial concentration of reactant, humidity, oxygen content and light intensity on the effect of the heterogeneous photocatalytic reaction along with the development of reaction kinetic model based on above parameters. Under experimental conditions, the maximum reaction rate for decomposing DCE was 0.959 μmole/s-g and quantum yield of 0.297. The concentration effect was in proportion to reaction rate but inversely to conversion ratio. As oxygen being a good electron accepter, the reaction rate increased with increasing oxygen content, but for higher than 15%(v/v), the reaction rate no longer increased. The functions of water were twofold: one being the source of hydroxyl free radicals, and the other for competing with DCE on adsorption sites. For lower moisture content, reaction rate increased with increased moisture content, but reversed under high moisture content. Stronger light intensity increased reaction rate with proportion to 0.6 order of light intensity. The kinetic expression could be represented by Langmuir-Hinshelwood bimolecular reaction model.