Thermochimica Acta 519 (2011) 59–64 Contents lists available at ScienceDirect Thermochimica Acta journal homepage: www.elsevier.com/locate/tca Effect of heating rate and sample geometry on the apparent specific heat capacity: DSC applications T. Kousksou a,∗ , A. Jamil b , K. El Omari a , Y. Zeraouli a , Y. Le Guer a a Laboratoire des Sciences de l’Ingénieur Appliquées à la Mécanique et au Génie Electrique (SIAME), Université de Pau et des Pays de l’Adour – IFR – A. Jules Ferry, 64000 Pau, France b École Supérieure de Technologie de Fès, Université Sidi Mohamed Ibn Abdelah, Route d’Imouzzer BP 2427, Morocco article info Article history: Received 30 November 2010 Received in revised form 16 February 2011 Accepted 17 February 2011 Available online 2 March 2011 Keywords: Heat transfer PCM Specific heat capacity DSC Melting Enthalpic method abstract Differential scanning calorimetry (DSC) and numerical simulations have been used to determine some kinetics parameters of phase change materials (PCM). The heating rate affects the development of the DSC thermograms and also the apparent specific heat capacity of the PCM during the phase change process. PCM geometry has also a definitive influence on the DSC thermograms and on the apparent specific heat capacity but seems to have no effect on the latent heat energy calculations. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Thermal energy storage (TES) is very important in many energy systems [1–3]. The advantages of using TES systems are to bal- ance the energy supply and demand, or to collect energy irregularly generated like solar energy for late use. The development history of latent storage systems is the devel- opment history of storage materials. Among the most extensive references related with phase change materials (PCMs), one can cite Abhat et al. [4], Husnain [5], Dincer [6], Mohammed et al. [7], Felix Regin et al. [1] and Zalba et al. [8]. These contain a complete review of the type of materials that have been used, their classifica- tion, characteristics, advantages and disadvantages and the various experimental techniques used to determine the behavior of these materials during melting and solidification processes. Phase change materials (PCM) are thermal storage materials with a high storage density for small temperature range applica- tion. The design of a thermal storage system within this narrow temperature range has to be founded on reliable and high resolu- tion material data. The accurate determination of the PCM’s heat storage capability as a function of temperature is crucial. ∗ Corresponding author. E-mail address: Tarik.kousksou@univ-pau.fr (T. Kousksou). DSC is one of the most widely used analytical instruments because of the ease with which it can provide large amounts of thermodynamic data [9]. From a single DSC test that consists in reg- ularly cooling down and heating of a sample, it is expected to obtain qualitative and quantitative information on the phase transitions of a sample, such as transition temperature, enthalpy, thermal con- ductivity, heat capacity, specific heat, and latent heat [10–14]. The accuracy of DSC measurements of standard materials is discussed in detail by Richardson [15] and Rudtsh [16]. Concerning DSC mea- surements of PCM, the accuracy of the measurement is dominated by the heating and sample size. The purpose of this work is to illustrate the effect of heating rate and sample geometry on the apparent specific heat capacity of the PCM samples. 2. Experimental Thermal analysis was carried out using a PYRIS DIAMOND DSC of PerkinElmer. The temperature scale of the instrument was care- fully calibrated by the melting point of pure ice (273.15 K or 0 ◦ C) and mercury (234.32 K or -38.82 ◦ C). The principle of the power- compensation used in the present study is widely detailed in Refs. [9,17]. We have already presented the experimental cell in Ref. [17], which consists of a cylindrical cell of height Z 0 = 1.1 mm and radius R = 2.215 mm (Fig. 1). 0040-6031/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.tca.2011.02.033