Analysis of Closed Loop Pulsating Heat Pipe b...

Analysis of Closed Loop Pulsating Heat Pipe by using Optimization Techniques with Binary Fluids

Author Name : K. Sai Prakash, K. Prahlada Rao, J. Venkata Suresh

ABSTRACT

Closed Loop Pulsating Heat Pipes (CLPHPs) have emerged as heat transfer devices as an alternative to conventional heat transfer technologies. The main reason for choosing heat pipes over other heat transfer devices are their great efficiency in transferring heat.

The heat transfer capability of PHPs mainly depends on the working fluid, evaporation and condensation lengths, inner diameter, and number of turns, etc. Kammuang-lue et al studied that, the higher latent heat of the working fluid, the higher the critical heat flux.

The analysis of closed loop pulsating heat pipe was carried out by using Taguchi method. Taguchi method is one of the statistical approaches to optimize the parameters and improve the quality. An experimental work will be carried out on a 5-turn pulsating heat pipe by varying working parameters such as fill ratio, heat input, angle of inclination, working fluid, etc., that affects the performance of CLPHPs on thermal resistance were studied. The binary fluids such as water-acetone, water-methanol and water-ethanol were employed for experimentation. Then the Taguchi method is employed to analyze the effect of working parameters of the closed loop pulsating heat pipe to predict the optimum design parameters. In Taguchi method, L18 orthogonal array is selected, and the best optimum parameters are identified based on the main effect plot for means and signal to noise ratio plot under the criteria of smaller is better. Analysis of variance (ANOVA) was carried out to identify the significant factors affecting the thermal resistance response and it was found that heat input is the most significant factor followed by fluid, inclination angle and fill ratio respectively. From the analysis, the performance of CLPHP is maximum when water-methanol as working fluid with a fill ratio of 50% and operated at 0^o inclination with a heat input of 60W and from the experimental results, that optimum value is 0.27289 ^oC/W.

Keywords: Taguchi Method, ANOVA, Closed Loop Pulsating Heat Pipe, Binary-Fluids, Optimization, Heat Input, Inclination Angle, Fill Ratio