In the industry, in many areas it is important to control temperatures in machines and pipes. When transporting heat from the production place to the place of use methods have to be found to keep the temperature loss as low as possible. In other applications temperature rise should be as low as possible and the cooling preferably efficiently.

In this application the aim is to transport a heated liquid with a minimum of heat loss from one point of the plant to another. Therefore it is necessary to identify the points with the highest loss of heat. Among other things the temperature is influenced by flow velocity in the pipe, by the diameter of the pipe and the outside temperature.

In figure 1 the flow behavior of a fluid in the pipe is shown. As you can see in figure 1, the highest flow velocity is in the center of the pipe, towards the walls of the tube the speed decreases. So we can conclude the slow-flowing fluid at the walls of the tube cools down faster than the current in the middle of the line. The reason is that the slow stream at the walls needs more time to get to the target point and so the contact with the cold outside of the pipe is longer. Figure 2 illustrates the temperature profile of the tube.  We can see the decreasing temperature in process. The fluid cools down because of the lower outside temperature. One possibility to reduce this effect would be a insulation of the pipe. By FEM calculation we can calculate the expected temperature of the liquid at the point of use. With this information customers in the development of the plants are able to decide if isolation is necessary. The thickness of the insulation layer may also be determined with the aid of FEM calculations.