scholarly journals THERMAL PERFORMANCE OF CLOSED LOOP PULSATING HEAT PIPE USING PURE AND BINARY WORKING FLUIDS

2013 ◽  
Vol 3 (3) ◽  
Author(s):  
Pramod R. Pachghare ◽  
Ashish M. Mahalle
Keyword(s):  
Heat Pipe ◽  
Thermal Performance ◽  
Closed Loop ◽  
Pulsating Heat Pipe ◽  
Working Fluids

Effect of Inclination Angle on the Closed Loop Pulsating Heat Pipe Thermal Performance

2013 ◽  
Author(s):  
Pramod R. Pachghare ◽  
Ashish M. Mahalle
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Inclination Angle ◽  
Heat Input ◽  
Closed Loop ◽  
Pulsating Heat Pipe ◽  
Working Fluids ◽  
Inclination Angles ◽  
R 134A

The closed loop pulsating heat pipe (CLPHP) is a passive two-phase heat transfer device, patented by Akachi (1990). Due to its excellent features, PHP has been considered as one of the promising technologies for electronic cooling, heat exchanger, etc. This paper presents an experimental study shows the effect of inclination angle on the thermal performance of CLPHP, which consist of 10 turns of copper tubes having inner and outer diameter 2 mm and 3.6 mm respectively. The equal lengths of evaporator, condenser and adiabatic sections are 50 mm each. Different working fluids are used as R-134a, Methanol and Water. For all experimentations, an optimum filling ratio was maintained 50% by volume. The thermal performance have been investigated with different inclination angles (viz. 0°, 20°, 40°, 60° and 90°) at various heat input from 5 to 50W in the steps of 5W. The thermal resistance (which is inversely proportional to thermal performance) of CLPHP at various heat input are plotted for different working fluids. The result shows that, the thermal resistance decreases as heat input increases. But at low heat input i.e. upto 25W, the thermal resistance decreases rapidly and the PHP performance is more sensitive to the inclination angle whereas high heat input i.e. above 25W, the thermal resistance decreases smoothly and less independent to the inclination angle. In all inclination angles, vertical bottom heat position (at 90°) of CLPHP gives best thermal performance due to presence of gravity force. At all inclination angles, the working fluid R-134a show best thermal performance followed by methanol and water.

Experimental Study on Thermal Performance of a Silicon-Based Micro Pulsating Heat Pipe

2009 ◽  
Author(s):  
Jian Qu ◽  
Huiying Wu ◽  
Ping Cheng
Keyword(s):  
Heat Pipe ◽  
Thermal Performance ◽  
Filling Ratio ◽  
Sustained Oscillation ◽  
Pulsating Heat Pipe ◽  
Working Fluids ◽  
Horizontal Orientation ◽  
Higher Power ◽  
Power Inputs ◽  
Silicon Based

In this paper, an experimental investigation was conducted on the thermal performance of a silicon-based micro-pulsating heat pipe (SMPHP) using FC-72 and R113 as working fluids. The SMPHP, covering an area of 46 × 19mm2, consisted of fourteen meandering trapezoidal channels with a hydraulic diameter of 352μm. The effects of gravity, filling ratio, and working fluids on the overall thermal resistance of the SMPHP were discussed. Experimental results show that gravity had an impact on the thermal performance of the SMPHP, and self-sustained oscillation could not be achieved at the horizontal orientation. The SMPHP worked as a true pulsating device when the filling ratio varied from 30% to 65%. For FC-72 and R113, there was an optimal filling ratio of 55% and 41%, respectively, for the best thermal performance of the SMPHP. As compared to the SMPHP with 0% filling ratio (or charged with the air), the thermal resistances of the SMPHP charged with FC-72 (at 55% filling ratio) and R113 (at 41% filling ratio) were decreased maximally by 7.24°C/W (or 56.5%) and 7.51 °C/W (or 59.7%), respectively. It is also found that the R113 was favorable for the operation of the SMPHP at lower power inputs, while FC-72 was favorable at relatively higher power inputs.

Experimental Investigations on the Thermal Performance of a Single Closed Loop Pulsating Heat Pipe Using TiO2 Nanofluid

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
G. V. Pradeep ◽  
K. Rama Narasimha
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Closed Loop ◽  
Experimental Investigations ◽  
Pulsating Heat Pipe ◽  
Vertical Orientation ◽  
Stable Suspension ◽  
Bottom Heating ◽  
Heating Mode

This paper describes the experimental investigations conducted on a closed loop pulsating heat pipe (CLPHP) for assessing the thermal performance. The pulsating heat pipe has a single closed loop made of copper. The working fluids used are water and titanium dioxide nanofluids with varying concentrations of TiO2 nanoparticles (1.5% and 1%) on weight basis. The TiO2 particles are mixed in water to form a stable suspension using a sonicator. The heat input is varied between 40 W and 100 W in steps of 20 W. All experiments are conducted in the bottom heating mode (evaporator at the top) in the vertical and horizontal orientations. The parameters considered for evaluating the thermal performance are the temperature difference between evaporator and condenser, thermal resistance, heat transfer coefficient, and thermal conductivity. The results of the investigation reveal that the vertical orientation and increase in nanoparticle concentration favors better heat transfer performance of the single closed loop pulsating heat pipe.

Sign in / Sign up

Export Citation Format

Share Document