scholarly journals Experimental and Numerical Study of Heat Pipe Heat Exchanger with Individually Finned Heat Pipes

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5317
Author(s):  
Grzegorz Górecki ◽  
Marcin Łęcki ◽  
Artur Norbert Gutkowski ◽  
Dariusz Andrzejewski ◽  
Bartosz Warwas ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Numerical Study ◽  
Heat Pipes ◽  
Relative Difference ◽  
Working Fluid ◽  
Staggered Arrangement ◽  
Brute Force Method ◽  
Air Conditioning Systems ◽  
Pipe Heat

The present study is devoted to the modeling, design, and experimental study of a heat pipe heat exchanger utilized as a recuperator in small air conditioning systems (airflow ≈ 300–500 m3/h), comprised of individually finned heat pipes. A thermal heat pipe heat exchanger model was developed, based on available correlations. Based on the previous experimental works of authors, refrigerant R404A was recognized as the best working fluid with a 20% heat pipe filling ratio. An engineering analysis of parametric calculations performed with the aid of the computational model concluded 20 rows of finned heat pipes in the staggered arrangement as a guarantee of stable heat exchanger effectiveness ≈ 60%. The optimization of the overall cost function by the “brute-force” method has backed up the choice of the best heat exchanger parameters. The 0.05 m traversal (finned pipes in contact with each other) and 0.062 m longitudinal distance were optimized to maximize effectiveness (up to 66%) and minimize pressure drop (less than 150 Pa). The designed heat exchanger was constructed and tested on the experimental rig. The experimental data yielded a good level of agreement with the model—relative difference within 10%.

Numerical Study of Heat Pipes Effects to a 3-Dimensional Room With Natural Driven Ventilation

2014 ◽  
Author(s):  
Z. Abdullah ◽  
B. P. Huynh ◽  
A. Idris
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Flow Pattern ◽  
Numerical Study ◽  
Heat Pipes ◽  
Working Fluid ◽  
3 Dimensional ◽  
Sharp Edges ◽  
Computational Fluid Dynamics Cfd ◽  
Pipe Heat

A Computational Fluid Dynamics (CFD) software package is used to investigate numerically a 3-dimensional rectangular-box room installed with heat pipes heat exchanger (HPHE). Heat pipe heat exchanger utilizing refrigerant by mean of working fluid is installed on top of a room. The air-side heat transfer and the flow pattern of a thermo-siphon heat pipes is studied with a natural driven ventilation of a building. Different opening of the inlet and outlet air where the heat pipe was installed are tested with round edges opening as well as sharp edges. The standard RANS k–ε turbulence model is used. Results with different setting of heat pipe and opening characteristic, air flow rate and flow pattern as well as its temperature effects are examined.

Metallic Mesh as Capillary Structure Applied in Heat Pipe Heat Exchanger for Heat Recovery

2014 ◽  
Vol 1082 ◽  
pp. 309-314 ◽  
Author(s):  
Diogo L.F. Santos ◽  
Larissa S. Marquardt ◽  
Paulo H.D. Santos ◽  
Thiago Antonini Alves
Keyword(s):  
Stainless Steel ◽  
Heat Exchanger ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Working Fluid ◽  
Capillary Structure ◽  
Porous Wick ◽  
Metallic Mesh ◽  
Heat Loads ◽  
Pipe Heat

This work presents a theoretical and experimental analysis of a heat exchanger assisted by five heat pipes made of copper with a metallic mesh 100 of stainless steel which was used as capillary structure. All heat pipes used water as the working fluid and were designed based on the capillary limit model. The heat pipes were developed and tested under heat loads varying from 20 to 50 W before application into the heat exchanger. The theoretical and experimental results were compared and all heat pipes worked satisfactorily. Thereafter, it is presented the development of heat pipe heat exchanger which was tested under heat loads varying from 100 to 250 W. The highest temperature measured on the external surface of the heat pipes was 90 oC and the heat exchanger thermal efficiency varied from 74 to 80%. It is showed that the use of a stainless steel mesh as a porous wick was proved to work successfully in heat pipes.

scholarly journals Experimental investigation of a heat pipe heat exchanger for heat recovery

2018 ◽  
Vol 45 ◽  
pp. 00012
Author(s):  
Anna Bryszewska-Mazurek ◽  
Wojciech Mazurek
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Working Fluid ◽  
Air Velocity ◽  
Condensation Zone ◽  
Evaporation Zone ◽  
Air Stream ◽  
Face Velocity ◽  
Pipe Heat

An air-to-air heat pipe heat exchanger has been designed, constructed and tested. Gravity-assisted wickless heat pipes (thermosiphons) were used to transfer heat from one air stream to another air stream, with a low temperature difference. A thermosiphon heat exchanger has its evaporation zone below the condensation zone. Heat pipes allow keeping a more uniform temperature in the heat transfer area. The heat exchanger consists of 20 copper tubes with circular copper fins on their outer surface. The tubes were arranged in a row and the air passed across the pipes. R245fa was used as a working fluid in the thermosiphons. Each heat pipe had a 40 cm evaporation section, a 20 cm adiabatic section and a 40 cm condensation section. The thermosiphon heat exchanger has been tested in different conditions of air stream parameters (flows, temperatures and humidity). The air face velocity ranged from 1,0 m/s to 4,0 m/s. The maximum thermal efficiency of the thermosiphon heat exchanger was between 26÷40%, depending on the air velocity. The freezing of moisture from indoor air was observed when the cold air temperature was below - 13°C.

scholarly journals Experimental study on utilization of heat pipe heat exchanger for improving efficiency of clean room air system in hospitals

2018 ◽  
Vol 67 ◽  
pp. 02056
Author(s):  
Imansyah Ibnu Hakim ◽  
Nandy Putra ◽  
Adam Prihananda Marda ◽  
Muhammad Alvin Alvaro ◽  
Adi Winarta
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Heat Recovery ◽  
Heat Pipes ◽  
Working Fluid ◽  
Hvac System ◽  
Clean Room ◽  
Huge Amount ◽  
Pipe Heat ◽  
The Ideal

Heating, Ventilation, and Air Conditioning (HVAC) system in hospital's clean room is required to continue working for 24 hours to provide the ideal air quality for the activities therein. This causes a huge amount of energy consumption in hospital buildings itself. This study aims to determine the effectiveness and heat recovery of Heat Pipe Heat Exchanger (HPHE). The HPHE used in this study consisted of 12 heat pipes per module, in which the line was arranged staggered. The number of the module is varied 3 times, which are 1, 2, and 3 modules. The heat pipe is made of copper and contains working fluid in the form of water with 50% filling ratio. HPHE equipped with fins to expand the contact surface with airflow. Each variation of the number of modules is tested on the HVAC system model of the clean room. In the evaporator inlet, air flowing to the variation of temperature: 28, 30, 35, and 40°C, and at speeds of 1.5, 2.0, 2.5 m/s. The use of HPHE can recover heat as much as 1654.72 kJ/h. The highest effectiveness of this HPHE is 48.729%, was obtained when using three modules, air temperature inlet evaporator (Te,i) = 35°C, and airspeed of inlet 1.5 m/s.

Experimental Study on Applied Thin Vapor Chamber and Embedded Heat Pipe Heat Sinks

2009 ◽  
Author(s):  
Garrett A. Glover ◽  
Yongguo Chen ◽  
Annie Luo ◽  
Herman Chu
Keyword(s):  
Heat Pipe ◽  
Heat Sink ◽  
High Performance ◽  
Structural Integrity ◽  
Heat Pipes ◽  
Electronic Cooling ◽  
Working Fluid ◽  
Vapor Chamber ◽  
Trade Offs ◽  
Pipe Heat

The current work is a survey of applied applications of passive 2-phase technologies, such as heat pipe and vapor chamber, in heat sink designs with thin base for electronic cooling. The latest improvements of the technologies and manufacturing processes allow achievable heat sink base thickness of 3 mm as compared to around 5 mm previously. The key technical challenge has been on maintaining structural integrity for adequate hollow space for the working fluid vapor in order to retain high performance while reducing the thickness of the overall vapor chamber or flattened heat pipe. Several designs of thin vapor chamber base heat sink and embedded heat pipe heat sink from different vendors are presented for a moderate power density application of a 60 W, 13.2 mm square heat source. Numerous works have been published by both academia and commercial applications in studying the fundamental science of passive 2-phase flow technologies; their performance has been compared to solid materials, like aluminum and copper. These works have established the merits of using heat pipes and vapor chambers in electronic cooling. The intent of this paper is to provide a methodical approach to help to accelerate the process in evaluating the arrays of different commercial designs of these devices in our product design cycle. In this paper, the trade-offs between the different types of technologies are discussed for parameters such as performance advantages, physical attributes, and some cost considerations. This is a bake-off evaluation of the complete heat sink solutions from the various vendors and not a fundamental research of vapor chambers and heat pipes — for that, it is best left to the vendors and universities.

Applying heat pipes to a novel concept aero engine: Part 1 – Design of a heat-pipe heat exchanger for an intercooled aero engine

2011 ◽  
Vol 115 (1169) ◽  
pp. 393-402 ◽  
Author(s):  
R. Camilleri ◽  
S. Ogaji ◽  
P. Pilidis
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Fuel Efficiency ◽  
Heat Pipes ◽  
Civil Aviation ◽  
Pressure Losses ◽  
Aero Engine ◽  
Core Concepts ◽  
Novel Concept ◽  
Pipe Heat

Abstract Civil aviation has instilled new perceptions of a smaller world, creating new opportunities for trade, exchange of cultures and travelling for leisure. However, it also brought with it an unforeseen impact on the environment. Aviation currently contributes to about 3·5% of the global warming attributed from human activities. With the forecasted rate of growth, this is expected to rise to about 15% over the next 50 years. Although it is projected that the annual improvements in aircraft fuel efficiency are of the order of 1-2%, it is suggested that the current gas turbine design is fully exploited and further improvements are difficult to achieve. A new generation of aero engine core concepts that can operate at higher thermal efficiencies and lower emissions is required. One possibility of achieving higher core efficiencies is through the use of an inter-cooled (IC) core at high overall pressure ratios (OPR). The concept engine, expected to enter into service around 2020, will make use of a conventional heat exchanger (HEX) for the intercooler. This paper seeks to introduce a heat pipe heat exchanger (HPHEX) as an alternative design of the intercooler. The proposed HPHEX design takes advantage of the convenience of the geometry of miniature heat pipes to provide a reduction in pressure losses and weight when compared to conventional HEX. The HPHEX will be made of a number of stages, each stage being made of a large number of miniature heat pipes in radial configuration, that will extend from the inter-compressor duct to the bypass split, thus eliminating any ducting to and from the intercooler. This design offers up to 32% reduction in hot pressure losses, 34% reduction in cold pressure losses and over 41% reduction in weight.

Numerical Simulation Study on Local Enhanced Heat Transfer for High Temperature Heat Pipe Heat Exchanger

2011 ◽  
Vol 396-398 ◽  
pp. 897-903
Author(s):  
Shi Mei Sun ◽  
Jing Min Zhou
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Temperature Distribution ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Fluid Temperature ◽  
Temperature Heat ◽  
High Temperature Heat Pipe ◽  
Pipe Heat

A High Temperature Heat Pipe Heat Exchanger Consists of Heat Pipes Filled with Different Working Media inside. in Different Temperature Zones, Heat Pipes with Different Working Media Are Linked Safely by Controlling the Vapor Temperature, the Media inside the Heat Pipe. the Vapor Temperature inside the Pipe Is Heavily Affected by the Temperature Field of Fluid outside the Heat Pipes and the Heat Transfer Performance inside the Heat Pipe, while the Heat Transfer Performance inside the Pipe in Turn Has a Bearing on the Temperature Distribution of Fluid outside the Pipe. to Coordinate the Fluid Temperature Distribution both inside and outside the Pipes, Study on Local Heat Transfer Enhancement Has Been Conducted on High Temperature Heat Pipe Heat Exchanger in this Article, and Cfd Computational Software Was Used to Make Rational and Accurate Prediction of Fluid Temperature Distribution both inside and outside the Pipes, so as to Provide Economic and Reliable Design Basis for High Temperature Heat Pipe Heat Exchanger.

Applying heat pipes to a novel concept aero engine: Part 2 – Design of a heat-pipe heat exchanger for an intercooled-recuperated aero engine

2011 ◽  
Vol 115 (1169) ◽  
pp. 403-410
Author(s):  
R. Camilleri ◽  
S. Ogaji ◽  
P. Pilidis
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Gas Turbine ◽  
Heat Exchangers ◽  
Heat Pipes ◽  
Advisory Council ◽  
Pressure Losses ◽  
Aero Engine ◽  
Cold Pressure ◽  
Pipe Heat

Abstract With the ever-increasing pressure for cleaner and more fuel efficient aero engines, gas turbine manufacturers are faced with a big challenge which they are bound to accept and act upon. The path from current high bypass ratio (BPR) engines to ultra high BPR engines via geared turbo fans will enable a significant reduction in SFC and CO2 emissions. However, in order to reach the emission levels set by the advisory council for aeronautics research in Europe (ACARE), the introduction of more complex cycles that can operate at higher thermal efficiencies is required. Studies have shown that one possibility of achieving higher core efficiencies and hence lower SFC is through the use of an intercooled recuperated (ICR) core. The concept engine, expected to enter into service around 2020, will make use of a conventional fin plate heat exchangers (HEX) for the intercooler and a tube type HEX as the recuperator. Although the introduction of these two components promises a significant reduction in SFC levels, they will give also rise to higher engine complexity, pressure losses and additional weight. Thus, the performance of the engine relies not only on the behaviour of the usual gas turbine components, but will be heavily dependent on the two heat exchangers. This paper seeks to introduce a heat pipe heat exchanger (HPHEX) as alternative designs for the intercooler and the recuperator. The proposed HPHEX designs for application in an ICR aero engine take advantage of the convenience of the geometry of miniature heat pipes to provide a reduction in pressure losses and weight when compared to conventional HEX. The proposed HPHEX intercooler design eliminates any ducting to and from the intercooler, offering up to 32% reduction in hot pressure losses, 34% reduction in cold pressure losses and over 41% reduction in intercooler weight. On the other hand the proposed HPHEX recuperator design can offer 6% improvement in performance, while offering 36% reduction in cold pressure losses, up to 80% reduction in hot pressure losses and over 31% reduction in weight. An ICR using HPHEX for the intercooler and recueprator may offer up to 2·5% increase in net thrust, while still offering 3% reduction in SFC and up to 7·7% reduction in NOX severity parameter, when compared to the ICR using conventional HEX.

The Design of Heat Pipe Heat Exchanger for CO2 EGS

2013 ◽  
Vol 479-480 ◽  
pp. 284-288
Author(s):  
Jui Ching Hsieh ◽  
David T.W. Lin ◽  
Wei Mon Yan ◽  
Long Der Shin
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Heat Pipes ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Air Velocity ◽  
Hot Gas ◽  
Experimental Apparatus ◽  
New Energy ◽  
Pipe Heat

The findings of new energy and energy harvester are the important issues for the lacking of fossil energy. For the purpose of the effective usage of supercritical CO2flowed from the product well of CO2EGS (Enhanced Geothermal System), an innovative heat pipe heat exchanger (Hx) is designed and practiced in this study. This study presents an innovative Hx of heat pipe for extracting the heat from CO2or warm gas. By using the heat pipe for cooling gas is the fundamental idea of this Hx. The experimental apparatus of Hx consists a heating blower to blow out hot gas, a circulating cool water device, and a set of heat pipes. The efficiency of Hx is approved as the increasing air velocity and the more fins gradually. This innovative heat pipe exchanger is proofed through our experiment. This heat pipe Hx is suitable for the application of enhanced geothermal system (EGS) and more energy harvesting application.

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