PCM in a Finned Tube

Phase Change Material (PCM) in a Finned Tube — ANSYS Fluent CFD Simulation

Description

This project presents a CFD analysis of thermal energy storage using Erythritol phase change material (PCM) in a three-layer tube heat exchanger with copper fins. PCMs store and release thermal energy through latent heat — absorbing heat as they melt from solid to liquid and releasing it as they solidify — which makes them well suited to applications such as capturing solar energy during the day and releasing it at night. This simulation investigates the phase-transition dynamics and heat-transfer mechanisms of the PCM over an extended charging period. Within the Solidification & Melting: Beginner CFD Training Package, this project applies the phase-change model to a finned tube, showing how enhanced surfaces overcome the low thermal conductivity that limits PCMs.

Methodology

The system is a three-layer tube heat exchanger with enhanced surfaces: copper tubes and fins for superior thermal conductivity, Erythritol as the PCM in the storage layer, and liquid silicone as the heat-transfer fluid circulating through the inner tube. The domain — inner-tube flow path, copper tube walls, fins, and PCM region — is meshed with a hybrid structured/unstructured grid of 107,718 elements, with coupled wall conditions between the different materials. The Solidification and Melting module handles the phase transition, run as an extended 12,000-second transient analysis to capture the complete phase dynamics. The Erythritol PCM is defined through its solidus and liquidus temperatures, latent heat of fusion, density, specific heat, and thermal conductivity, while the copper tubes and fins carry high thermal conductivity. The silicone heat-transfer fluid enters at 343.15 K and 1 m/s, the outer walls are adiabatic (zero heat flux), and the inner walls are automatically coupled thermal interfaces.

Analysis

Post-processing visualizes the temperature distribution through the PCM, tracks the progression of the solid-liquid phase front over time, and quantifies the liquid-fraction development as the PCM melts, along with the heat-transfer pathways — conduction through the fins and convection in the liquid regions. From these results you can evaluate the energy-storage capacity absorbed as latent heat, the transient response during charging, the effectiveness of the fins in enhancing heat transfer, and how heat penetrates from the tube surface into the PCM volume — yielding practical design guidance on fin geometry and spacing, flow rate, and inlet temperature. The results highlight how copper fins accelerate the charging process and overcome the inherent thermal-conductivity limitation of PCMs. By the end of this project, you'll be able to set up an extended transient Solidification and Melting simulation with coupled solid–fluid–PCM zones, define PCM and fin material properties, and interpret the phase-front, liquid-fraction, and temperature results that characterize a finned PCM heat exchanger.

Note: since your list now has both #1 (finned tube, described here as a three-layer tube exchanger) and #7 (shell-and-tube finned heat exchanger), just keep an eye that those two stay clearly differentiated when you write #7 — different geometry framing so they don't read as duplicates.