Challenges in the computer modeling of phase change materials
Izzivi v računalniškem modeliranju materialov s fazno spremembo

english

2012

volume 46, issue 4

phase change material (PCM)   enthalpy method   effective heat capacity method   solar air collector

Inštitut za kovinske materiale in tehnologije
(Obvezni izvod spletne publikacije)

Phase-change materials (PCMs) are a well-established category of materials with many possible applications, ranging from the stabilization of temperature to heat or cold storage. The main principle of PCMs is the utilization of the latent heat of a phase change for energy storage. Though many pure chemical elements can be used as PCMs, a PCM very often consists of a number of substances. The main reason for creating a PCM as a mixture of various substances is to achieve a desirable melting temperature for a particular application. However, these mixed PCMs require accurate and reliable methods for determining their physical properties, since for numerical modeling the thermal properties of materials and their proper determination represent a significant issue that considerably affects the accuracy and credibility of numerical simulations and their outcomes. The thermal properties of PCMs are usually obtained by differential scanning calorimetry (DSC), based on temperature and heat measurements of the investigated and reference materials. There are several approaches to modeling materials with phase changes. In this paper, the focus is on the enthalpy approach and the effective heat capacity method. Both techniques, which utilize the results from a particular DSC measurement, allow a treatment with the latent heat, and as a result the desired heat or cold storage may be effectively simulated. The presented methods were implemented using the results from DSC measurements in order to simulate a solar air collector with a PCM. The obtained results are presented and discussed. The paper also concerns the problems associated with the uncertainty of material properties and their influence on numerical simulations.

10.07.2013