The hottest oscillating flow heat pipe technology

Oscillating flow heat pipe technology has been used in the drying industry

because the energy consumption of drying equipment accounts for a high proportion of industrial energy consumption, energy conservation in the drying process is of great significance. Generally, energy efficiency can be improved by improving the heat and mass transfer in the drying process or reducing the energy consumption of the drying system to achieve the purpose of energy conservation. In the common convection drying system, on the one hand, it can improve the heat transfer efficiency of the heat exchanger or hot blast stove, on the other hand, it can recover the waste heat discharged by the drying system

oscillating flow heat pipe is also called pulsating heat pipe. The working principle of this new heat pipe is very different from that of the traditional heat pipe, and its heat transfer performance is much better than that of the traditional heat pipe. This oscillating flow heat pipe has the following outstanding advantages: there is no need for capillary cores in the heat pipe, which is conducive to the realization of miniaturization, the heat transfer performance is not affected by the heating position (top, bottom or horizontal heating can be used), and it can be bent at will and started quickly. Therefore, for plastic design, oscillating flow heat pipe has great application prospects in drying system

obviously, the efficiency of waste heat recovery is closely related to the performance of heat exchangers. Therefore, it is necessary to carry out the research on heat transfer enhancement of oscillating flow heat pipe. According to the operation mechanism of oscillating flow heat pipe, two ways can be adopted to strengthen the heat transfer of oscillating flow heat pipe: one is to strengthen the heat exchange between the working fluid in the pipe and the wall of the heat pipe; the other is to increase the oscillation frequency in the pipe, and Masteel will reduce the equivalent rate of 40 yuan/ton and the circulating power. The author used the following two methods in the study: (1) pulse heating instead of traditional continuous heating; (2) The non-uniform heat pipe channel section replaces the usual uniform section. The strengthening effect of these two methods is studied by experiments and compared with the traditional heat pipe. The following experimental results are obtained:

(1) the heat transfer performance of pulse heating and continuous heating under the same heating power is compared in the experiment. The temperature oscillation frequency and amplitude of oscillating flow heat pipe during pulse heating are higher than the corresponding values during continuous heating, and the heat transfer heat flow and equivalent thermal conductivity of oscillating flow heat pipe during pulse heating can be significantly enhanced. Under the same heating power, the heat transfer heat flow rate of pulse heated oscillating flow heat pipe is 15% - 38% higher than that of continuous heating, and the equivalent thermal conductivity is 12% - 63% higher. At the same time, the wall temperature fluctuation of evaporation section and condensation section under different heating methods is studied. It is concluded that pulse heating can enhance the oscillating flow in the oscillating flow heat pipe

(2) experiments show that the heat transfer of oscillating flow heat pipe can be enhanced by increasing the pulsation frequency and amplitude of oscillating flow. Because the heat transfer enhancement effect of the oscillating flow heat pipe heated by the pulse @b panel key function is related to the pulse width and intermittent time, there may be a more effective optimal pulse width and intermittent time, so it is necessary to further study the coupling effect of internal and external field enhancement of the heat pipe

(3) the author also compared the heat transfer performance of oscillating flow heat pipe with non-uniform flow section with that of uniform section through experiments. When the heating power is greater than 100W, the heat transfer heat flow and equivalent thermal conductivity of non-uniform cross-section oscillating flow heat pipe are significantly higher than that of uniform cross-section heat pipe, and will increase with the increase of heating power. Therefore, under certain conditions, the heat transfer performance of oscillating flow heat pipe can be improved by changing its flow cross-section. The experimental results show that the heat transfer performance of oscillating flow heat pipe is much higher than that of pure conductor copper pipe