Effect of ultrasonic on the enhancement of heat transfer for pulsating heat pipe

Abstract

Summary The pulsating heat pipe (PHP) has become one of the most promising devices to dramatically remove heat for electronic devices. This work focuses on the experimental investigation of ultrasonic on the enhancement of heat transfer of PHP, and further discusses this effect at the different working fluids. The results indicate that the external region of PHP exhibits more intense oscillation motion of working fluids than that of internal‐region. The heat transfer performance enhanced assisted with the ultrasonic at the heating power of 5 to 20 W but deteriorated at 25 W. For details, the heat transfer coefficient (HTC) increased 72.6%, and the internal and external start‐up times reduced 57.8% and 2.2%, respectively. Furthermore, the numerous vapors confirm that the ultrasonic cavitation would effectively accelerate the phase transition. Finally, it also discusses the couple effect between the ultrasonic and different working fluids on heat transfer coefficient. The maximum HTC of 1.85 is obtained at the heating power of 15 W for the PHP charged with acetone. In addition, the trend of HTC of PHP filled with acetone shows much more stable assisted with ultrasonic varying from the heating power inputs. Highlights The thermal performance was revealed by internal and external region of PHP The directly enhanced method of ultrasonic cavitation was introduced The novel index of the heat transfer coefficient (HTC) was proposed The couple effect ultrasonic on the enhancement of heat transfer was discussed with different working fluids

Analysis of ultrasonic composite pulsating heat pipe reinforced phase change material heat storage research

“…Cao et al [14] designed a PHP coupled with Phase Change Materials (PCMs) for heat storage research, PHP as a heat tr ansfer medium, solved the problems of low thermal conductivity of PCMs and heat loss during heat transfer, an d accelerated the PCMs heat storage. Zhang et al [15] studied the effect of the coupling of ultrasonic waves and different working fluids on the heat transfer coefficient. PHP with acetone as the working fluid obtained a heat transfer coefficient of 1.85 times at a heating power of 15W; the heat transfer coefficient of the acetone-filled P HP is more stable with the assistance of ultrasound.…”

Experimental analysis of a novel device for accelerating the energy storage rate of phase change materials

“…The results showed that when methanol was the filling working medium, the optimal filling rate was 0.3. Zhang et al 12 studied the heat transfer efficiency of PHP under ultrasonic field. The experimental results show that ultrasonic cavitation effectively enhances the heat transfer efficiency of PHP.…”