In this project, a shell and tube heat exchanger has been simulated using Fluent. The shell and tube heat exchanger has the most significant application in the industry and is the most suitable type of exchanger for high-pressure and high-temperature applications. Shell and tube heat exchangers consist of tubes arranged inside a cylindrical shell, also called a shell and tube heat exchanger. A fluid flows inside the tubes, and another fluid flows around the tubes (inside the shell), and heat is transferred from one fluid to the other through the tube walls due to the temperature difference between the two fluids.
The way shell and tube heat exchangers work is that fluid flows inside a set of tubes connected at the inlet and outlet while another fluid with a different temperature flows inside the shell surrounding the tubes. Heat is transferred from the hot fluid to the cooler one through the tube walls due to the temperature difference between the two fluids. Heat transfer occurs without any direct contact between the two fluids. This exchanger type is widely used in industries and for controlling the temperature of various fluids.
In this project, the cold fluid is water, and the hot fluid is oil. Water enters the exchanger at a temperature of 283 Kelvin, and the oil enters at 375 Kelvin. In this exchanger, the oil is cooled by water, and its temperature decreases.
This project has been simulated in 3D, and Space Claim software has been used to generate its geometry. The meshing of this geometry has been performed by Ansys Meshing software, and after meshing, the “make polyhedral” option in Fluent has been utilized to convert the tetrahedral elements to polyhedral elements. In total, 1765114 elements have been used for this project.
The inlet velocity for both water and oil is 0.1 m/s. The solver used for this simulation is the pressure-based solver, and the simulation has been carried out in a steady-state condition. Second-order discretization has been utilized for the energy, momentum, and pressure equations to achieve higher accuracy.
After performing the simulation, we can observe the oil temperature in the tube. Based on the temperature contours, the oil temperature decreases significantly after passing through the first row of tubes and becomes almost equal to the water temperature. We can increase the oil flow rate or inlet velocity to control the oil output temperature. As the oil velocity in the pipes increases, it has less opportunity to transfer heat with water. Generally, we can control the output temperature of the oil by changing the oil flow rate or the length of the pipes.