Experimental Study On Heat Transfer Enhancement In Tube-sheet Heat Exchanger By Ultrasonic Wave

Heat transfer enhancement technology is a hot research topic at present. This paper explores the ultrasonic enhanced heat transfer technology and heat transfer enhancement in tube-sheet heat exchanger by ultrasonic wave was studied.The basic principle of ultrasonic technology in the enhancement of heat transfer is analyzed and at the same time the experimental platform of ultrasonic enhanced heat transfer characteristics was developed. In the experimental study water work as the fluid medium and the ability of ultrasonic heat transfer enhancement under different fluid velocity and fluid temperature is analyzed. The experimental results show that with the increase of flow velocity, the effect of ultrasonic enhanced heat transfer is gradually increased, but the amplitude of the increase will decrease and tend to be stable. The results also show that with the increase of water temperature, the effect of ultrasonic enhanced heat transfer is more obvious, and the heat transfer rate in the experiment can reach 126%.The effect of ultrasonic wave power and gas bearing ratioon of water content on the heat transfer enhancement of ultrasonic wave is studied. Test results show that the change of ultrasonic power hardening rate will subsequently changed greatly. When the power is less than a certain value, the enhancement rate increased with the increase of power, however, more than the power enhanced rate will slow tends to a stable value, the increase of power and do not have too big change. In addition to containing gas rate of rate hardening effect is very significant, the media has a gas holdup, when the actual gas rate is less than this value can significantly improve the effect of heat transfer enhancement,but higher than the value of the strengthening effect is weakened. It is found that the effect of high power and high gas content is good for cavitation, but the enhancement of heat transfer effect is not entirely dependent on the cavitation effect.The economic analysis of the ultrasonic enhanced heat transfer system is carried out, and the economic coefficient is obtained by the comprehensive experimental conditions, performance is the ratio of the average heat exchange rate to the average heat exchange rate obtained by the input of the electric energy to the ultrasonic generator in the test.Finally, the combination of test data analysis under different conditions of transfer enhancement heat process, summed up for the test used for ultrasonic heat exchanger of the optimum parameters of heat transfer enhancement, is enhanced by ultrasonic wave for thermal system design and application of reference.