The Numerical Simulation Of Heat Transfer In Dimple Jacket And Its Application

In the early 1990s, dimple jacket, as a new and high-efficient jacket, has been invented and widely used in the food industry, chemistry industry, and sanitation due to its excellent mechanical and heat transfer properties. Compared with the common jacket, the wall thickness of jacket and inner chamber can be greatly reduced , and the manufacturing cost for the dimple jacket can be reduced greatly from the point of strength. On the other hand, from the point of heat transfer, the jacket interval of dimple is smaller than that of common jacket and that leads to the smaller circulation area. In this way, the fluid flow velocity increases obviously, and a large number of honeycombs play a role in flow disturbance. When the fluid flows through the honeycomb, the flow direction and velocity are changed continually and turbulent vortex is formed, which make the heat/cold exchange accelerated and improves the heat transfer performance. However, there are few reports on the research of the heat transfer coefficient of the dimple, so it is urgent to research the heat transfer performance of the dimple.In order to study the fluid heat transfer of the dimple jacket equipment and investigate the theory basis of the design and magnification of the equipment, a mathematical model is developed. CFD software is used to simulate the heat transfer coefficient of the dimple jacket with water as the jacket cooling media and the conducted oil as heating media. The main results can be summarized as following:(1) The heat transfer mathematical model of dimple jacket is established based on the motion and energy equations, continuous flow equations. The established equations are solved by means of FLUENT software. The numerical results reveal that the heat transfer coefficient of dimple jacket is much higher than that of common jacket. Increasing the velocity and reducing flow dead angle areas can significantly improve the heat transfer coefficient in dimple jacket and enhance the heat transfer effect.(2) The heat transfer performance ofφ600 dimple jacket is numerically analyzed by using the k -εturbulence model. The comparison between the experimental data and numerical results reveals that they have the same variation trends with the heat transfer coefficients of the heat exchanging.