A Pillow Plate Heat Exchanger is a special device used in factories to heat or cool fluids. It is made of thin metal sheets welded together. When fluid flows inside, the sheets puff out like a “pillow.” This wavy shape is very important because it changes how the fluid moves. Designing these plates is difficult, so engineers use Pillow Plate Heat Exchanger CFD to test them on a computer. This helps us see if the design is efficient before building it.

In this tutorial, we perform a complete ANSYS Fluent simulation of a pillow plate passage. We use a special liquid called a “nanofluid” to improve the cooling power. The goal is to calculate how much heat moves from the hot walls to the liquid. We also check the pressure drop to ensure the pumps can handle the flow. This CFD Analysis of Pillow Plate is essential for creating energy-saving systems. For more examples of thermal analysis, please visit our Heat Exchangers CFD Simulation tutorials.

• Reference [1]: Tran, J. M., et al. “Investigation of pillow-plate condensers for the application in distillation columns.” Chemical Engineering Research and Design99 (2015): 67-74.
• Reference [2]: Piper, M., et al. “Determination of the geometric design parameters of pillow-plate heat exchangers.” Applied Thermal Engineering91 (2015): 1168-1175.
• Reference [3]: Shirzad, Mojtaba, et al. “Improve the thermal performance of the pillow plate heat exchanger by using nanofluid: numerical simulation.” Advanced Powder Technology7 (2019): 1356-1365.

Figure 1: Schematic diagram showing the internal wavy flow path of a pillow-plate heat exchanger.

Simulation Process: Nanofluid Thermal Modeling in ANSYS Fluent

To perform this Plate Heat Exchanger Fluent simulation, we first designed a 3D geometry of a single passage inside the pillow-plate. We then used ANSYS Meshing to create a very fine and accurate grid, especially near the curved walls where heat transfer occurs. Inside the ANSYS Fluent solver, we set up the simulation to model a heating process. The working fluid was a special single-phase nanofluid with custom properties. This was done because nanofluids have better thermal conductivity than regular fluids. The nanofluid enters the heat exchanger at a cool temperature of 298 K. To heat it, we set the curved pillow-plate walls to a constant hot temperature of 305 K. This setup allows us to precisely model the convective heat transfer from the solid walls to the moving nanofluid.

Figure 2: The 3D geometry model of the single pillow-plate passage used for the ANSYS Fluent CFD simulation.

Post-processing: CFD Analysis of Thermal Performance in a Plate Heat Exchanger

This section provides a detailed engineering analysis of the Plate Heat Exchanger CFD results. We will explain how the unique shape of the pillow-plate leads to its excellent thermal performance. First, we analyze the fluid movement using the velocity streamlines in Figure 4. The streamlines show that the fluid does not flow in a simple straight line. The curved, “pillow” shape of the walls forces the fluid to swirl and create secondary flows and vortices. This is a deliberate and brilliant design feature. These swirling motions are extremely important because they constantly mix the fluid. The cooler liquid from the center of the channel is pulled outwards and forced to touch the hot walls. This continuous mixing action is the primary reason for the high rate of heat transfer. The geometry itself is actively improving its own performance.

Next, we look at the temperature contours in Figure 3 to see the direct result of this excellent mixing. The nanofluid heats up very smoothly and uniformly as it travels through the channel. The simulation shows that the fluid exits at a final average temperature of 301.45 K. This is a temperature rise of 2.45 K, which is a significant increase for such a short passage. The numbers confirm this high performance. The simulation calculated a very high mean heat flux of 26,877 W/m². Most importantly, it calculated a convective heat transfer coefficient of 6,139 W/m²·K. This is an extremely high value and is direct proof of a highly effective heat transfer process.

Figure 3: Temperature contours showing the uniform heating of the nanofluid as it flows through the pillow-plate heat exchanger.

Figure 4: Velocity contours displaying flow patterns and mixing zones

Figure 4: Velocity streamlines displaying the swirling flow patterns and mixing zones that enhance heat transfer.

Finally, we must consider the “cost” of this performance, which is the pumping power needed, measured by the pressure drop. The simulation measured a pressure drop of 770.3 Pa and a friction factor of 0.204. For such high thermal performance, these values are considered moderate. This means the heat exchanger provides excellent heating without requiring a very powerful and expensive pump. The most important conclusion from this CFD analysis is that the design is highly efficient and well-balanced. It proves that the secondary flows caused by the geometry are directly responsible for the high heat transfer coefficient, validating this pillow-plate design as a superior thermal solution.

Key Takeaways & FAQ

• Q: Why is a pillow-plate heat exchanger so effective?
  • A: Its curved, “pillow” shape creates swirling flows that constantly mix the fluid, forcing the cool fluid to touch the hot walls.
• Q: What does the heat transfer coefficient of 6,139 W/m²·K mean?
  • A: It is a very high number that proves heat is moving from the walls to the fluid extremely quickly and efficiently.
• Q: Is the pressure drop of 770.3 Pa good or bad?
  • A: It is good. It is a moderate value, which means the design achieves excellent heating without needing too much pumping power.