Transient Analysis of a Flat Heat Pipe Working as a Passive Air Conditioning System in Residential Buildings

2004 ◽  
Author(s):  
Gustavo Gutierrez ◽  
Juan Catan˜o
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Sink ◽  
Transient Analysis ◽  
Residential Buildings ◽  
Temperature Drop ◽  
Heat Pipes ◽  
External Irradiation ◽  
Actual Performance ◽  
Flat Heat Pipe

In this study, a flat heat pipe is proposed to use the enormous heat capacity of the soil as a heat sink to remove heat from the ambient and a the same time provides a heat pathway for the external irradiation so that the thermal insulation of the construction is significantly improved. Heat pipes offer an effective and attractive alternative since they work with a small temperature budget. Heat pipes use the latent heat of vaporization as a heat transfer mechanism and provide a very high effective conductivity. Heat pipes are not thermodynamics cycles then do not suffer from the Carnot limitation. Temperature drop in the vapor core is very small and the vapor provides an almost isothermal condition. The operational temperature of a heat pipe is controlled by the conditions in the condenser (in this case, the soil). So, providing an effective heat transfer pathway in the condenser, the vapor temperature will be closed to the temperature of the soil. Soil temperature does not fluctuate bellow certain distance from the surface and in a tropical climate is always cooler that the ambient and can function as a heat sink. As part of this research, a full transient analysis of the operation of a flat heat pipe is carried out. With the insight of numerical results, a flat heat pipe thermal panel can be constructed and tested to verify the feasibility and actual performance of the flat heat pipe panel.

Heat Spreading Analysis of a Heat Sink Base Embedded With a Heat Pipe

2005 ◽  
Author(s):  
Brian V. Borgmeyer ◽  
H. B. Ma
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Convection Heat Transfer ◽  
Transfer Performance ◽  
Uniform Temperature ◽  
Convection Heat Transfer Coefficient ◽  
Flat Heat Pipe ◽  
Heat Spreading

A simplified theoretical model predicting the heat transfer performance of a heat sink base embedded with a flat heat pipe is developed. Numerical analysis was performed using the commercial software FLUENT. The investigation indicates that for heat sink bases embedded with a typical heat pipe, the entire heat sink can be modeled as a flat plate with a uniform temperature and an effective convection heat transfer coefficient. The prediction is compared with the experimental data obtained previously.

An Experimental Investigation of a High Flux Heat Pipe Heat Sink

2004 ◽  
Author(s):  
H. B. Ma ◽  
K. P. Lofgreen ◽  
G. P. Peterson
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Pipe ◽  
Heat Sink ◽  
Temperature Drop ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Forced Air ◽  
Pipe Heat

An experimental investigation on a highly efficient heat pipe heat sink was investigated, in which the interline region was optimized using sintered particles. The effects of condenser size, sintered particles, and forced air flow on the heat transfer performance were investigated experimentally. The experimental results indicated that the thin film evaporation could significantly increase the evaporating heat transfer coefficient and remove heat fluxes up to 800 kW/m2. In addition, a theoretical model capable of predicting the temperature drop occurring in the device was developed. The predicted performance was in good agreement with the experimental data. The resulting model can be used to assist in the design of high heat flux, heat pipe heat sinks for applications to both ground based and spacecraft applications.

Development of Thinned Aluminum Flat Heat Pipe Through Inclined Wall and Press Process

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Seok-Hwan Moon ◽  
Su-Hyun Hong ◽  
Hyun-Tak Kim
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Heat Dissipation ◽  
Heat Pipes ◽  
System Level ◽  
Total Thickness ◽  
Capillary Structure ◽  
Flat Heat Pipe

Heat pipes, commonly used for heat dissipation and thermal management in small electronic and communication devices, are regarded as an excellent solution. Heat pipes must be in surface rather than line contact to be applied to the module and system-level heat dissipation package. As such, a round copper heat pipe is transformed into a plate-like shape through a secondary press process. In this study, an extrusion structure is designed to be sloped to solve the difficulty of making it relatively thin compared with the large area of the plate structure. Specifically, substantial partitions separating the working fluid flow space in the plate-type heat pipe are designed to be inclined at 45 deg, and the extruded envelope is developed to obtain the desired total thickness through the secondary press process. The capillary structure is inserted and positioned within the envelope prior to the secondary press process. In this study, an aluminum flat heat pipe (AFHP) with 0.95 mm total thickness, 150 mm total length, and a capillary structure with braided or carbon wire bundles added thereto was designed and manufactured. Performance test results indicated that the heat transfer performance of the AFHP with inclined wall did not show any deterioration characteristic compared with the AFHP with a normal vertical wall. The isothermal characteristics and heat transfer rate of the AFHP with Cu braid wick were superior to those of AFHP with a simple rectangular groove wick. By contrast, when the carbon wire bundle is added in the Cu braid, the isothermal characteristic was enhanced twice, and the heat transfer rate was 15.5 W by improving approximately 42% under the conditions that inclination angle is −90 deg and the evaporator temperature does not exceed 110 °C.

scholarly journals Heat Pipe System as a Component of Spacecraft Electronics

2021 ◽  
pp. 363-377
Author(s):  
Nikita Yu. Sokolov ◽  
Vladimir A. Kulagin ◽  
Dmitry A. Nesterov
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Electronic Devices ◽  
Heat Pipes ◽  
Optimization Method ◽  
Maximum Temperature ◽  
Pipe System ◽  
Heat Transfer Capacity ◽  
The Mathematical Model ◽  
Flat Heat Pipe

We report on the results of optimizing a single flat heat pipe into an arrangement of heat pipes. A comparison is drawn at the same temperatures and occupied volumes and for a specific maximum temperature of radio-electronic devices. The end result of our studies is that the limiting heat transfer capacity has been found for a single heat pipe and two- and three-level heat pipe assemblies with various heat transfer media. Versatility of the mathematical model enhanced by the optimization method has been proved

An Experimental Investigation of a High Flux Heat Pipe Heat Sink

2005 ◽  
Vol 128 (1) ◽  
pp. 18-22 ◽  
Author(s):  
H. B. Ma ◽  
K. P. Lofgreen ◽  
G. P. Peterson
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Pipe ◽  
Heat Sink ◽  
Temperature Drop ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Forced Air ◽  
Pipe Heat

An experimental investigation of a highly efficient heat pipe heat sink was investigated, in which the interline region was optimized using sintered particles. The effects of condenser size, sintered particles, and forced air flow on the heat transfer performance were investigated experimentally. The experimental results indicated that the thin film evaporation could significantly increase the evaporating heat transfer coefficient and remove heat fluxes up to 800kW∕m2. In addition, a theoretical model capable of predicting the temperature drop occurring in this device was developed. The predicted performance was in good agreement with the experimental data and the resulting model can be used to assist in the design of high heat flux, heat pipe heat sinks.

An Experimental Study on the Thermal Performance of the Flat Heat Pipe

2016 ◽  
Author(s):  
Hao Xiaohong ◽  
Jiqing Guan ◽  
Jingbo Zhao
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Electronic Devices ◽  
Heat Pipes ◽  
Deionized Water ◽  
Working Fluid ◽  
Nano Fluid ◽  
Flat Heat Pipe

As the rapid growing of the semiconductor logic gate number and operation speed, the heat dissipated from electronic devices increases drastically. Moreover, most of the heat flux can reach about 100 W/cm2, therefore efficient removal of the heat from the electronic devices is essential to ensure the reliable operation of the electronic devices. The traditional direct cooling system, such as air cooling, liquid cooling, would not be able to transfer the high heat flux owing to their heat transfer limits, so advanced cooling solutions are necessary. The flat heat pipes have some advantages, such as small scale, strong heat transfer capacity, low weight penalty and low environmental requirements, therefore, in recent years, researchers have shown great interest for the flat heat pipe. But most of them played the important on the structure design of the flat heat pipes, and few of them focused on the study of the effect of the working fluid on the heat transfer performance. In this paper, a flat heat pipe with rectangular channel is designed and manufactured, and an experimental set up was built to study working fluid on the effects of the flat heat Pipe thermal performance. The flat heat pipe is heated via a 35mmx20mm rectangular electrical resistance (the evaporator side), and the other side (the condenser side) is cooled by convection of a heat sink. In the experimental work, three types of working fluid are used in the heat pipe: (A) deionized water, (B) deionized water-based Fe3O4 nano fluid (1, 1.5wt%). A comparison is performed for the thermal performance of different size flat heat pipe. Finally, the experimental results showed that nano fluid could improve the thermal performance of the FHP. With the same charge volume, the heat transfer coefficient of the FHPs filled with nano fluid were higher than that of DI water. There was an optimal mass concentration which was estimated to be 1.5 wt% to achieve the maximum heat transfer enhancement.

scholarly journals Testing algorithm for heat transfer performance of nanofluid-filled heat pipe based on neural network

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 751-760
Author(s):  
Lei Lei
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Volume Fraction ◽  
Heat Pipes ◽  
Transfer Performance ◽  
Analysis Model ◽  
Accurate Analysis ◽  
Testing Algorithm

AbstractTraditional testing algorithm based on pattern matching is impossible to effectively analyze the heat transfer performance of heat pipes filled with different concentrations of nanofluids, so the testing algorithm for heat transfer performance of a nanofluidic heat pipe based on neural network is proposed. Nanofluids are obtained by weighing, preparing, stirring, standing and shaking using dichotomy. Based on this, the heat transfer performance analysis model of the nanofluidic heat pipe based on artificial neural network is constructed, which is applied to the analysis of heat transfer performance of nanofluidic heat pipes to achieve accurate analysis. The experimental results show that the proposed algorithm can effectively analyze the heat transfer performance of heat pipes under different concentrations of nanofluids, and the heat transfer performance of heat pipes is best when the volume fraction of nanofluids is 0.15%.

Theoretical Investigation of Heat Pipes Operating at Low Vapor Pressures

1968 ◽  
Vol 90 (4) ◽  
pp. 547-552 ◽  
Author(s):  
E. K. Levy
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Dimensional Analysis ◽  
Theoretical Investigation ◽  
Heat Pipes ◽  
Vapor Pressures ◽  
One Dimensional ◽  
Evaporator Section ◽  
Heat Transfer Capacity ◽  
Theoretical Results

A one-dimensional analysis of a compressible vapor flowing within the evaporator section of a heat pipe is presented. Comparisons between the theoretical results and existing heat pipe data show that the presence of gasdynamic choking can limit the heat transfer capacity of a heat pipe operating at sufficiently low vapor pressures.

Sign in / Sign up

Export Citation Format

Share Document