Numerical Simulation Of Heat Transfer Characteristics In Heat Exchange Tube With A Built-in Arc Belt

The heat transfer enhancement is an important way of rational use of energy and energy saving.Its purpose is to improve energy efficiency.In the actual production and life,the application of heat transfer enhancement technology is widely used in heat exchanger.The heat exchanger is the main equipment of the heat exchange and transfer.Laminar flow in tube occurs in many heat transfer equipment.Due to the low heat transfer coefficient of the laminar flow field,thereby it has important practical significance to increase the heat transfer capability of the equipment under low Reynolds number condition.Therefore,in this paper,the large-scale software FLUENT is used for the simulation and calculation on flow and heat transfer performance of the three-dimensional model for the heat transfer tubes inserted Arc Belt by using the numerical simulation method.First, based on the field synergy, seven kinds of different structure parameters of the inserts are studied. The heat transfer enhancement mechanism is obtained by the simulation and analysis of the velocity field and temperature field. The turbulence of the inserts plays a role to make velocity field synergy between temperature field and stress field better, so the heat transfer can be enhanced. The (entranspy) equivalent thermal resistance of dissipation principle is utilized to analysis of the irreversibility of the heat transfer tube heat exchanger. Compared to the smooth tube under the same conditions, equivalent thermal resistance of tubes within inserts is much smaller than that of the smooth tube. Equivalent thermal resistance is smaller, the smaller the irreversibility of the heat exchanger. Heat transfer enhancement is to enable the irreversibility of the heat exchanger weakened.Second, through simulation and calculation of tubes within inserts and smooth tubes under the same conditions, the graph of heat transfer and flow characteristics of heat exchange tubes is drawn. Through comparative analysis, heat transfer performance of enhanced tube has been greatly improved compared to the smooth tube, and also the flow resistance has a corresponding increase. And through the comprehensive evaluation and analysis of the enhanced tube flow and heat transfer performance by adopting an integrated performance evaluation method, it is obtained: under the same pump power conditions, in the range of Re=600-1800, these tubes have use value and No.3tube h12s78b6has the best integrated heat transfer performance.Finally, according to the results of numerical simulation of the heat transfer and flow models parametric curves under different conditions are drawn. The influence of height to diameter ratio, spacing to diameter ratio and width to diameter ratio on heat transfer and flow performance is obtained.Through comparative analysis, within the scope of the research, under the same conditions, the arc is narrower, the more conducive to improve the integrated performance. And the heat transfer can be increased with narrow spacing. According to the results of the numerical simulation, the Nusselt number Nu and the drag coefficient f criteria formula is fitted out which has a certain reference value to the improvement of the heat transfer performance of the heat transfer tube in the practical application of engineering. At last, through simulation and analysis of heat transfer performance of the tubes with the crude oil of high viscosity fluid, when the high viscosity fluid flows in the tube, under the low Reynolds number, its overall performance is particularly evident. The heat transfer tube structure is simple, easy manufacturing and processing, suitable for large-scale industrial production, which has a broad development and application prospect.