A highly technological marvel, the U-tube shell and tube heat exchanger effectively transfer heat between two fluids while retaining their separation. Its complicated design is a U-shaped bundle of tubes in a cylindrical shell. The tubes carry one fluid while the shell circulates the other. Heat exchange is improved by maximizing fluid surface area contact. U-tube shell and tube heat exchangers are precisely engineered for best thermal performance and operational dependability in industrial processes, HVAC systems, and power generation facilities. The U-tube shell and tube heat exchanger are modelled using ANSYS Fluent In three dimensions.

Figure 1: Geometry design of  U-tube Shell and Tube Heat Exchanger

Simulation Process

The 3D geometry is created by three zones, including tube, shell and tube walls. The circular cross-section of the tube is swept through a spline. Then, 1035902 tetrahedron cells are spread over the domain. The copper wall of the tube is expected to hasten the heat transfer. Cold water passes in the tube at a 290K temperature while the hot fluid passes at 360K in the shell.

Figure 2: Cross-sectional view of mesh produced for U-tube Shell and Tube Heat Exchanger

Post-processing

The U-tube shell and tube heat exchanger’s modeling results tell us a lot about how well it works with heat and fluids. The temperature contours show that there is a huge heat transfer process going on inside the device. The cold water that comes into the tubes at 290K warms up to 311.48K as it moves through the exchanger. This shows that the fluid on the shell side is effectively absorbing heat. At the same time, the temperature of the fluid on the shell side drops from 360K to 311.65K, showing that the heat has been removed successfully. This two-way heat transfer shows how well the exchanger works to help the thermal energy move between the two streams of liquids.

Figure 3: Temperature distribution in U-tube Shell and Tube Heat Exchanger

From the point of view of fluid mechanics, the velocity contours show a maximum flow rate of 2.73 m/s, which is mostly seen near the inlet and exit areas. The U-bend shape creates complicated flow patterns, such as Dean vortices and secondary flows, which are especially clear in the bent parts. By breaking up boundary layers and encouraging radial mixing, these flow patterns improve mixing and heat transfer. The difference in temperature along the flow path, which is especially noticeable in the U-bend area, supports the idea that fluid dynamics and heat transfer work together. The overall temperature change in both fluid streams (21.48K rise in tube-side and 48.35K drop in shell-side) shows that the heat exchanger can make big temperature changes. This makes it useful for many industrial and HVAC uses where precise temperature control is needed.

Figure 4: Velocity distribution in U-tube Shell and Tube Heat Exchanger