scholarly journals A review on Mechanism of fluid flow and Transfer of Heat in Closed Loop Pulsating Heat Pipe

2020 ◽  
Vol 184 ◽  
pp. 01056
Author(s):  
Venkata Suresh Javvadi ◽  
Bhramara Panitapu ◽  
Rajith Gangam ◽  
Hrishikesh Kulkarni
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Pipe ◽  
Coupling Effect ◽  
Working Fluid ◽  
Internal Diameter ◽  
Pulsating Heat Pipe ◽  
Operational Mechanism ◽  
Theoretical Investigations ◽  
Thermodynamic Coupling

Now-a-days the researchers and people are moving towards such an innovation which meet the needs of the present without compromising the ability of future generations to meet their own needs. In such innovations Pulsating heat pipe is one of the technology which started in 1990 by Akachi. Pulsating heat pipe is a heat transfer device which has an effective heat transfer capability. The researchers had done many experimental and theoretical investigations, but they haven’t got the complete knowledge about it because of its complex operational mechanism which consists of hydrodynamic and thermodynamic coupling effect. This paper gives a brief idea on the thermo-hydro dynamic characteristics of this device. The brief idea will be on internal diameter, cross-section of the tube and the amount of working fluid in system. In addition to all these the number of turns in device and thermo-physical properties of working fluid which leads to determine the thermal behavior. The motto of this paper is to make review paper on recent past years on papers which used refrigerants as working fluids and its fluid flow mechanism and finally lead upcoming researchers to have basic idea and future scope of device.

Operating Activity Visualization and Thermal Performance Measurement of Pulsating Heat Pipe

2016 ◽  
Vol 369 ◽  
pp. 42-47 ◽  
Author(s):  
Patrik Nemec ◽  
Zuzana Kolková ◽  
Milan Malcho
Keyword(s):  
Heat Transfer ◽  
Performance Measurement ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Vapour Phase ◽  
Working Fluid ◽  
Internal Diameter ◽  
Pulsating Heat Pipe ◽  
Inner Diameter ◽  
Thermo Physical Properties

Heat pipe is well known device which is used to heat transfer phase-change of working fluid. Pulsating heat pipe (PHP) is special type of heat pipe which heat transfer by pulsating movement of working fluid. Article deals about operating activity and thermal performance measurement of this special heat pipe. Operating activity visualization of PHP was performed with PHP made from glass. The two types of PHPs were made. The first PHP has internal diameter of tube 1 mm, second PHP has internal diameter of tube 1.5 mm and both PHPs have eleven meanders. The working fluids used in PHP were water and Fluorinert FC-72. These fluids were chose for their different thermo-physical properties and the visualization observe formation of liquid and vapour phase working fluid during filling process and working operation.Next, the article describes thermal performance measurement of PHP depending on working fluid amount and heat source temperature. Measurement was performed with PHP made from copper tube with inner diameter 1.5 mm curved to the twenty one meanders and filled with water. The results give us image about formation and distribution of working fluid in pulsating heat pipe and about influence of working fluid amount on the heat transfer ability of pulsating heat pipe.

Effects of Surface Coating of Nanoparticles on Thermal Performance of Open Loop Pulsating Heat Pipes

2012 ◽  
Author(s):  
Mehdi Taslimifar ◽  
Maziar Mohammadi ◽  
Ali Adibnia ◽  
Hossein Afshin ◽  
Mohammad Hassan Saidi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Surface Coating ◽  
Heat Pipes ◽  
Open Loop ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Performance Of Heat Transfer

Homogenous dispersing of nanoparticles in a base fluid is an excellent way to increase the thermal performance of heat transfer devices especially Heat Pipes (HPs). As a wickless, cheap and efficient heat pipe, Pulsating Heat Pipes (PHPs) are important candidates for thermal application considerations. In the present research an Open Loop Pulsating Heat Pipe (OLPHP) is fabricated and tested experimentally. The effects of working fluid namely, water, Silica Coated ferrofluid (SC ferrofluid), and ferrofluid without surface coating of nanoparticles (ferrofluid), charging ratio, heat input, and application of magnetic field on the overall thermal performance of the OLPHPs are investigated. Experimental results show that ferrofluid has better heat transport capability relative to SC ferrofluid. Furthermore, application of magnetic field improves the heat transfer performance of OLPHPs charged with both ferrofluids.

Experimental Investigation of Heat Transfer of Refrigerant Fluid Pulsating Heat Pipe

2017 ◽  
Vol 865 ◽  
pp. 137-142
Author(s):  
Somchai Maneewan ◽  
Chantana Punlek ◽  
Hoy Yen Chan ◽  
Atthakorn Thongtha
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Heat Pipe ◽  
Temperature Difference ◽  
Heat Input ◽  
Filling Ratio ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Filling Volume ◽  
Volume Filling

Heat transfer performances of a pulsating heat pipe (PHP) having internal and external diameter with 4.5 mm and 6 mm with various contents of refrigerant are experimentally investigated. The working fluid as R404A refrigerant was filled in the volume ratios from 0% to 80% and the heat input was controlled in the range from 10 W to 80 W. Obtained results exhibited the ability of R404A refrigerant can enhance the thermal performance in steady state condition. The average temperature difference of the evaporating section and condensing section in the 80% filling volume ratio decreased from 9.5 °C to 2.5 °C when the heating power increase from 10 W to 80 W. The thermal resistance of evaporator and condenser decreased with an increase of the heat input as well. For other filling volume ratios, the trend of temperature difference and thermal resistance was similar to that of the 80% volume filling ratio. Considering the same heat input, the highest heat transfer performance was found at the 80% volume filling ratio. Refrigerant with a relatively low dynamic consistency can lead to relatively high velocity in the PHP that can reduce the temperature difference between the evaporating section and condensing section.

Modeling for Fluid Flow and Heat Transfer in Closed Loop Pulsating Heat Pipe

2020 ◽  
pp. 1-34
Author(s):  
Radhakanta Sarangi ◽  
Satya Prakash Kar ◽  
Abhilas Swain ◽  
Lalit Kumar Pothal
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Vapor Bubble ◽  
Closed Loop ◽  
Working Fluid ◽  
Vapour Bubble ◽  
Pulsating Heat Pipe ◽  
Time Step ◽  
Liquid Plug ◽  
Evaporation And Condensation

Abstract Numerical modelling of multi turn Closed Loop Pulsating Heat Pipe (CLPHP) is presented in this paper for ethanol as working fluid. Modelling is carried out for 1mm and 2mm ID PHP for different number of turns, different orientations and at constant wall temperature boundary conditions. Momentum and heat transfer variations with time are investigated numerically solving the one dimensional governing equations for vapor bubble and liquid plugs. Evaporation and condensation takes place by heat transfer through liquid film present around the vapour bubble. The code takes into account the realistic phenomena such as vapour bubble generation, liquid plug merging and super heating of vapor bubbles above its saturation temperature. During merging of liquid plugs, a time step adaptive scheme is implemented and this minimum time step was found to be 10−7 s. Nature of flow is investigated by momentum variation plot. Model results are compared with the experimental results from literature for nine different cases. Maximum variation in heat transfer for all these cases is found to be below ±34%. Keywords: Closed Loop Pulsating Heat Pipe, Liquid Plug, Plug momentum, Vapor Bubble, Heat Transfer, Thin Film Evaporation and Condensation

Operational Mechanism of Square Capillary Looped Pulsating Heat Pipe

2010 ◽  
Author(s):  
Wei Qu ◽  
Bin Yang
Keyword(s):  
Heat Pipe ◽  
Driving Forces ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Flow Rates ◽  
Operational Mechanism ◽  
And Performance ◽  
Dynamic Diameter ◽  
Heat Transfers ◽  
Flow Resistances

Pulsating Heat Pipe (PHP) has the turn structure of capillary and the mechanism is paid much more attention. The circulation of Looped Pulsating Heat Pipe (LPHP) is modelled to couple the heat transfers, volume flow rates, operational driving forces and flow resistances. The analysis and calculation show that, the square capillary LPHP can be optimized by adjusting the coupled dominating parameters to improve the flow and performance. The working fluid, the transferred power and the dynamic diameter will exert essential influences on the LPHP performance, the thermal resistance of the LPHP can be as small as 0.05°C/W.

Experimental and numerical analysis of heat transfer and fluid flow characteristics inside pulsating heat pipe

2021 ◽  
pp. 1-17
Author(s):  
Chandrakant R. Sonawane ◽  
Kuldeep Tolia ◽  
Anand Pandey ◽  
Atul Kulkarni ◽  
Hitesh Punchal ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Analysis ◽  
Heat Pipe ◽  
Flow Characteristics ◽  
Pulsating Heat Pipe ◽  
Fluid Flow Characteristics

Model for Pulsating Heat Pipe With Capillary Wick and Varying Channel Diameter

2004 ◽  
Author(s):  
Brian M. Holley ◽  
Amir Faghri
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Momentum Equation ◽  
Channel Length ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Channel Diameter ◽  
Fill Ratio ◽  
Heating And Cooling ◽  
Enhancing Heat Transfer

Variation in channel diameter is investigated as a means of enhancing heat transfer in a pulsating heat pipe with capillary wick using the model presented here. The model is one-dimensional with slug flow where the momentum equation is solved for each liquid slug. The number and mass of liquid slugs are allowed to vary throughout a simulation. The energy equation is solved both in the wall and wick and in the working fluid. The effects of diameter profile, gravity, fill ratio, and heating and cooling schemes can be studied with the model. Results yield similar trends to what has been experimentally observed. Results also indicate that heat transfer can be enhanced when the diameter of the channel is varied along the channel length, thereby providing increased range of heat load capability, less sensitivity to gravity, and in some cases smaller temperature differentials.

The Start-Up Performance of Pulsating Heat Pipe With Communicating Pipe at Different Inclination Angles

2019 ◽  
Author(s):  
Fu-Min Shang ◽  
Shi-Long Fan ◽  
Jian-Hong Liu
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Working Fluid ◽  
Transfer Performance ◽  
Pulsating Heat Pipe ◽  
High Heat Transfer ◽  
Start Up ◽  
Inclination Angles

Abstract The pulsating heat pipe (PHP) is a passive cooling device, which has the advantages of simple structure, high heat transfer performance and low production cost. The complex vapor-liquid phase change occurs in the in the initial stage of PHP. In this work, we explore the start-up performance of PHP at different inclination angles and the experiment shows that start-up performance is respectively different when the angles are 0°, 45°, 90°, 135° and 180°. Since the gravitational auxiliary function, the working fluid in the communicating pipe which takes longer time to vaporize change phase earlier than that in PHP’s loop when the angles are 0° and 45°. Nevertheless, when the angle is 90°, the phase change of working fluid in communicating pipe and in the loop occurs at the same time. Meanwhile, the oscillating mode affects the stability of the starting and heat transfer performance of the PHP.

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