Showing papers on "Heat pipe published in 2016"
TL;DR: The use of heat pipes can potentially reduce the thermal resistance and pressure losses in the system as well as temperature regulation of the TEGs and increased design flexibility as discussed by the authors, but heat pipes do have limitations such as maximum rates of heat transfer and temperature limits.
360 citations
TL;DR: In this article, the authors highlight the importance of uniform PV cooling by exploring the possible causes and effects of non-uniformity on the surface of PV panels, and present an experimental case study for comparison between uniform and nonuniform cooling methods.
Abstract: Cooling of PV panels is a critical issue in the design and operation of concentrated photovoltaic (CPV) technology. Due to high cell temperature and non-uniform temperature distribution, current mismatching problem and hot spot occurs on the cell resulting in either reduction of efficiency or permanent structural damage due to thermal stresses. Temperature non-uniformity on the surface of PV panel has a major impact on the performance of CPV systems and directly increases cell temperature and series resistance. This review paper highlights the importance of uniform PV cooling by exploring the possible causes and effects of non-uniformity. Cooling techniques with low average cell temperature and uniform temperature distribution are analyzed. Economic and environmental impact on the importance of cooling of PV systems are discussed and an experimental case study is presented for comparison between uniform and non-uniform cooling methods. Immersion cooling is a promising solution for uniform cooling and has been reported to reduce the cell temperature to 20–45 °C for CPV systems. Heat pipes reduced the temperature down to 32 °C with the best case temperature non-uniformity of 3 °C. Passive cooling by heat sinks was found to reduce the cell temperature as low as 37 °C for high concentrations but with an expense of large heat sink area. Active cooling by microchannels, impingement cooling and hybrid microchannel-impingement cooling were found to be most effective in dissipating high heat flux from PV surface. Cell temperature was reported to decrease to 30 °C for 200× CPV using impingement cooling. For hybrid cooling, deviation of 0.46 °C surface temperature was obtained. Using PCM materials temperature of panel was controlled within 28–65 °C whereas optimization of heat exchanger designs also showed low and uniform temperature across surface. The impact of non-uniformity was found to be significant for all PV systems however the effect is more pronounced in CPV systems.
219 citations
TL;DR: In this article, the authors evaluated the effect of γ (gamma and α (alpha) Fe2O3/Kerosene nanofluids for a closed loop pulsating heat pipe under the magnetic field.
183 citations
TL;DR: In this paper, a flat plate loop heat pipe (FPLHP) was used as a heat exchanger in the thermal management system of the lithium-ion battery for electric vehicle application.
158 citations
TL;DR: In this paper, the effect of Fe2O3/Kerosene nanofluid to the copper closed-loop oscillating heat pipe under the magnetic field for inclination angles ranging from 0° to 90°, under different heat inputs (10 − 90 W).
158 citations
TL;DR: In this article, a phase change material/oscillating heat pipe (PCM/OHP)-based battery thermal management (BTM) system was compared with the OHP-cooled and PCM/OHP-based BTM system.
145 citations
TL;DR: In this article, the role of surface microstructures in two-phase microchannels on suppressing flow instabilities and enhancing heat transfer was investigated and a critical heat flux (CHF) of 969 W/cm2 was achieved with a structured surface, a 57% enhancement compared to a smooth surface.
Abstract: We investigated the role of surface microstructures in two-phase microchannels on suppressing flow instabilities and enhancing heat transfer. We designed and fabricated microchannels with well-defined silicon micropillar arrays on the bottom heated microchannel wall to promote capillary flow for thin film evaporation while facilitating nucleation only from the sidewalls. Our experimental results show significantly reduced temperature and pressure drop fluctuation especially at high heat fluxes. A critical heat flux (CHF) of 969 W/cm2 was achieved with a structured surface, a 57% enhancement compared to a smooth surface. We explain the experimental trends for the CHF enhancement with a liquid wicking model. The results suggest that capillary flow can be maximized to enhance heat transfer via optimizing the microstructure geometry for the development of high performance two-phase microchannel heat sinks.
135 citations
TL;DR: In this article, a solar concentrating thermoelectric generator using the micro-channel heat pipe array was designed, and the mathematical model was built, and a comparison of the experiment and the simulation between the SCEG generator and the micro channel heat pipe arrays was made. And the performance on the different areas of selective absorbing coating, different concentration ratios, different ambient temperatures, different wind speed all were analyzed.
130 citations
TL;DR: In this paper, a segmented thermal resistance model of a heat pipe is proposed based on thermal circuit method, and the equivalent conductivities of different segments, viz. the evaporator and condenser of pipe, are used to determine their own thermal parameters and conditions integrated into the thermal model of battery for a complete 3D computational fluid dynamics simulation.
127 citations
TL;DR: In this article, an experimental investigation has been carried out to examine the thermal performance of a sintered wick heat pipe using aqueous graphene nanoplatelets (GNP) nanofluids.
116 citations
TL;DR: In this paper, a two-dimensional finite volume based numerical model along with enthalpy-porosity technique is employed to simulate the phase change of storage media during the discharging mode.
TL;DR: In this article, a phase change thermal energy storage unit with copper foam was implemented in a shell-and-tube heat exchanger and compared with other heat exchangers such as finned copper tube, tube surrounded by carbon foam and a simple tube.
TL;DR: In this paper, heat pipes are incorporated into a thermal management system for prismatic or pouch cells, focusing on increasing cooling capacity and improving temperature uniformity of the system through sensitivity studies, and an empirical study is carried out to assess the thermal performance of the optimized design integrated with prismatic cells at the unit level and the battery pack level.
TL;DR: In this paper, a mathematical model was presented according to thermal and exergy analysis to analyze the collector performance and then the given system was constructed and experimentally tested according to a real consumption pattern.
TL;DR: In this paper, the phase change heat transfer performance of a PCM embedded in a porous metal fiber sintered felt (PMFSF) was investigated, and three types of heat sinks (filled with MF-PCM, filled with paraffin, and empty) were tested under four power levels.
TL;DR: In this article, a semi-analytical model was developed to characterize capillary-limited thin-film evaporation from silicon micropillar wicks in the absence of nucleate boiling, and the insights gained from experiments were used to model the capillary pressure, permeability, and thermal resistance.
TL;DR: In this article, the authors mainly studied the application of separated heat pipe system on data center cooling, which consists of four parts: evaporator, condenser, vapor pipe and liquid pipe.
TL;DR: In this paper, an integrated thermal management system combining a heat pipe battery cooling/preheating system with the heat pump air conditioning system is presented to fulfill the comprehensive energy utilization for electric vehicles.
TL;DR: In this paper, a three-dimensional CFD model of a wickless heat pipe was developed to simulate both the complex multiphase heat and mass transfer characteristics of boiling and condensation and the heat transfer characteristics in the cooling fluid in the condenser.
TL;DR: In this paper, the performance of a miniature loop heat pipe with graphene-water nanofluid was analyzed. But the authors only used a square flat evaporator having a size of 20mm×20mm, a compensation chamber placed above the evaporator and transport lines having different diameters.
TL;DR: In this article, two different heat pipe photovoltaic/thermal (PV/T) systems, namely, wickless heat pipe PV/T system and wire-meshed heat pipe P2P system, were proposed and experimentally investigated in an Enthalpy Difference Laboratory with a solar simulator.
TL;DR: In this paper, the authors present a mathematical model to study opportunities for simultaneous passive thermal management of an integrated PEM fuel cell and metal hydrogen (MH) storage system by thermal bridging of these two components, using heat pipes.
TL;DR: In this paper, a new CFD simulation of two phase flow inside thermosiphon heat pipe is carried out to investigate the effect of fill ratio (ratio of liquid volume to the evaporator volume) and inclination angle on its thermal performance in terms of temperature distribution and thermal resistance using FLUENT (ANSYS 15).
TL;DR: In this paper, the performance of a novel HDH solar desalination system equipped with a combination of heat pipe (HP), evacuated tube collector (ETC), and air bubble column humidifier is experimentally investigated.
TL;DR: In this paper, the effect of varying nitrogen-doped graphene (NDG) nanosheets concentrations, heat pipe inclination angles and input heating powers on the performance of a grooved heat pipe was analyzed.
TL;DR: In this paper, the effects of six different working fluids, hexane, petroleum ether, chloroform, acetone, methanol and ethanol on the energy and exergy performance are investigated in evacuated tube solar collectors with thermosyphon heat pipe under three different air velocities as 2, 3 and 4
TL;DR: In this article, a novel narrow-tube closed oscillating heat pipe model with two backward steps is proposed to enhance its heat transfer ability that is attributed to the oscillation cycle in a fixed direction.
TL;DR: In this article, three composite wick structures (copper power or mesh sintered on grooved tube) are proposed to improve the thermal performance of ultra-thin heat pipes (UTHPs), and the maximum heat transport capacities are 12 W, 13 W and 14 W, under the corresponding optimum filling ratios of 70, 70, and 80%, for the SSGW, BSGW and MGW UTHPs, respectively.
TL;DR: In this paper, the performance of paraffin wax coupled with closed-loop oscillating heat pipe (CLOHP) with different turns was investigated, and the results showed that when the whole width was constant, difficult or unstable oscillation tended to occur in the CLOHPs with less turns.