Experimental investigation and CFD analysis of a air cooled condenser heat pipe

Annamalai, Suresh Babu; Velraj, R.

doi:10.2298/tsci100331023a

Cited by 40 publications

(15 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Annamalai and Ramalingam [18] carried out an experimental investigation and CFD analysis of a wicked heat pipe using ANSYS CFX. The authors considered the region inside the heat pipe as a single phase of vapour and a wick region as the liquid phase.…”

Section: Introductionmentioning

confidence: 99%

Numerical modelling of the temperature distribution in a two-phase closed thermosyphon

Fadhl

Wrobel

Jouhara

2013

Applied Thermal Engineering

242

View full text Add to dashboard Cite

A B S T R A C TInterest in the use of heat pipe technology for heat recovery and energy saving in a vast range of engineering applications has been on the rise in recent years. Heat pipes are playing a more important role in many industrial applications, particularly in improving the thermal performance of heat exchangers and increasing energy savings in applications with commercial use. In this paper, a comprehensive CFD modelling was built to simulate the details of the twophase flow and heat transfer phenomena during the operation of a wickless heat pipe or thermosyphon, that otherwise could not be visualised by empirical or experimental work. Water was used as the working fluid. The volume of the fluid (VOF) model in ANSYS FLUENT was used for the simulation. The evaporation, condensation and phase change processes in a thermosyphon were dealt with by adding a user-defined function (UDF) to the FLUENT code. The simulation results were compared with experimental measurements at the same condition. The simulation was successful in reproducing the heat and mass transfer processes in a thermosyphon. Good agreement was observed between CFD predicted temperature profiles and experimental temperature data.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical modelling of the temperature distribution in a two-phase closed thermosyphon

Fadhl

Wrobel

Jouhara

2013

Applied Thermal Engineering

242

View full text Add to dashboard Cite

show abstract

“…It becomes obvious that the orientation of the TMMHP plays an important role in superheating quality of the fluids. On the other hand, in the case of SMMHP [6,7] the trend is always negative. Figure 14 indicates that water was condensed within the highest temperature band because of the highest specific heat (C p ) while the iso-propanol became the lowest.…”

Section: Evaporator Of Tmmhp As a Super Heatermentioning

confidence: 89%

“…It was observed from these figures that in each case of fluid used in TMMHP, there was a temperature rise in the evaporator from T 1 to T 2 . Annamalai A. S. et al [7] has reasoned that -In the evaporator zone heat is supplied by an electric coil and the coil surface area density is very high in the middle of the evaporator portion and hence the temperature of the vapor in the middle of the evaporator is high‖. Authors here disagree with Annamalai that there should be no reason to windup the heater coil densely in the middle of the evaporator rather wrapping must be uniformly done so the produced heat flux remains constant throughout the evaporator.…”

Section: Evaporator Of Tmmhp As a Super Heatermentioning

confidence: 99%

“…While an assumption of single phase flow in SMMHP works well at lower heat inputs, but at moderately high heat inputs it becomes a two-phase flow. However, the super heater effect at the evaporator in TMMHP eliminates that complexity of the two-phase and instantly turns into a single phase flow of vapor which was not possible in SMMHP [6,7]. 5.…”

Section: American Journal Of Mechanical Engineeringmentioning

confidence: 99%

See 1 more Smart Citation

Study of Two-Metal (Cu-Ag) Micro Heat Pipe of Square Cross Section Using Different Liquids of Low Boiling Point

Iqbal¹,

Akhanda²

2014

AJME

View full text Add to dashboard Cite

The efficiency-to-size ratio of the electronic machines has been increasing rapidly while leaving the electronics highly thermally stressed. In an attempt to solve the overheating issue, a comparative study is conducted between a two-metal (Cu-Ag) micro heat pipe and the contemporary single-metal one (Cu) which is currently being installed in the electronic equipment. Thermal effects of a two-metal square cross section micro heat pipe (MHP) at steady state are experimentally investigated. It is a 150 mm long square hollow tube having each side of 3.6 mm and thickness of 0.3 mm which holds a 3.0 mm hollow space axially. The evaporator and condenser sections are made of pure copper and silver respectively while the adiabatic section is made of both copper and silver. Water and three low boiling point liquids ─ ethanol, methanol and iso-propanol ─ are used as working fluids. In view of the usage of the actual equipment, tests are conducted by placing the heat pipe at three different inclinations of 0 o , 45 o and 90 o . To provide heat flux, an electric heater-coil has been wrapped around the evaporator simulating the heat-generation within an actual device, and simultaneously the condenser section is directly cooled by ambient water in an annular space. Internal fluid-flow is considered to be one dimensional. Ten K-type thermocouples are installed at different locations ─ five of them are to measure the temperatures of internal fluid and five are used to measure the surface temperatures of the tube. Temperatures are monitored by digital electronic thermometers. Unlike in the single-metal micro heat pipe (SMMHP), it is found that the super heater effect in the evaporator of TMMHP simplify the complex two-phase flow into a superheated vapor. Thus, it increases TMMHP's heat transfer capability multiple times higher than that of SMMHP.

show abstract

“…Annamalai and Ramalingam [20] carried out an experimental investigation and CFD analysis of a wicked heat pipe using ANSYS CFX. The authors considered the region inside the heat pipe as a single phase of vapour and the wick region as the liquid phase, and used distilled water as the working fluid.…”

Section: Introductionmentioning

confidence: 99%

CFD modelling of a two-phase closed thermosyphon charged with R134a and R404a

Fadhl

Wrobel

Jouhara

2015

Applied Thermal Engineering

164

View full text Add to dashboard Cite

This paper examines the application of CFD modelling to simulate the two-phase heat transfer mechanisms in a wickless heat pipe, also called a thermosyphon. Two refrigerants, R134a and R404a, were selected as the working fluids of the investigated thermosyphon. A CFD model was built to simulate the details of the two-phase flow and heat transfer phenomena during the start-up and steady-state operation of the thermosyphon. The CFD simulation results were compared with experimental measurements, with good agreement obtained between predicted temperature profiles and experimental temperature data, thus confirming that the CFD model was successful in reproducing the heat and mass transfer processes in the R134a and R404a charged thermosyphon, including the pool boiling in the evaporator section and the liquid film in the condenser section. INTRODUCTIONA wickless heat pipe is a two-phase heat transfer device with a highly effective thermal conductivity, containing a small amount of working fluid that circulates in a sealed tube utilising the gravity forces to return the condensate back to the evaporator [1]. When the evaporator section is heated by an external source, the heat will be transferred to the working fluid through the evaporator wall. The working fluid absorbs an amount of heat proportional to the latent heat of evaporation, which is sufficient to change the fluid from liquid to vapour. The vapour then moves to the condenser section where it changes phase again, back to liquid, along the condenser's wall, giving up its latent heat that it absorbed in the evaporator section. The condensed liquid is then returned to the evaporator due to gravitational or capillary forces, according to the type of heat pipe [1][2][3][4][5]. Heat pipes have been successfully used for waste heat energy recovery in a vast range of engineering applications, such as heating, ventilation, and air conditioning (HVAC) systems [2], ground source heat pumps [6], water heating systems [7] and electronics thermal management [8].The most important characteristics to consider in identifying suitable working fluids are compatibility and wettability with the heat pipe materials, good thermal stability and conductivity, high latent heat of evaporation, high surface tension and low viscosity for both liquid and vapour [9]. In typical thermosyphons, the selection of the working fluid and the shell materials is subject to the working environment and temperature under which the thermosyphon-based system will function. For low temperature applications, ammonia and various refrigerants such as R134a, R22 and R410a have been used as working fluids with copper, steel, aluminium and other compatible metals as shell materials. Water has been proven to be a suitable working fluid for temperatures between 30°C and 300°C, with good compatibility with various metals including copper and stainless steel. Liquid metals and various organic fluids have been selected for thermosyphons when the working temperature is above 300°C [6,[10][11][12][13][14].Two-phas...

show abstract

Experimental investigation and CFD analysis of a air cooled condenser heat pipe

Cited by 40 publications

References 29 publications

Numerical modelling of the temperature distribution in a two-phase closed thermosyphon

Numerical modelling of the temperature distribution in a two-phase closed thermosyphon

Study of Two-Metal (Cu-Ag) Micro Heat Pipe of Square Cross Section Using Different Liquids of Low Boiling Point

CFD modelling of a two-phase closed thermosyphon charged with R134a and R404a

Contact Info

Product

Resources

About