Journal Articles
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/19884
Browse
3 results
Search Results
Item A Computer Aided Cooling Curve Analysis method to study phase change materials for thermal energy storage applications(Elsevier Ltd, 2016) Sudheer, R.; Prabhu, K.N.The suitability of a simple Computer Aided Cooling Curve Analysis (CACCA) technique for characterizing thermal energy storage phase change materials (PCM) was proposed in the present work. Two modes of CACCA, namely, Newtonian and Fourier techniques were used to predict the phase transition temperatures, the latent heat of fusion and thermal diffusivities of PCMs. Solidification of potassium nitrate and zinc-8% aluminium alloy (ZA8) was studied using CACCA method. These PCMs were chosen to demonstrate the ability of the proposed technique to characterize PCMs freezing at a single temperature as well as over a range of temperatures. CACCA method showed that potassium nitrate and ZA8 are suitable candidate materials for TES applications operating at 300-350 °C and 350-450 °C respectively. © 2015 Elsevier Ltd.Item Cooling Curve Analysis of Micro- and Nanographite Particle-Embedded Salt-PCMs for Thermal Energy Storage Applications(Springer New York LLC barbara.b.bertram@gsk.com, 2017) Sudheer, R.; Prabhu, K.N.In recent years, the focus of phase change materials (PCM) research was on the development of salt mixtures with particle additives to improve their thermal energy storage (TES) functionalities. The effect of addition of microsized (50 ?m) and nanosized (400 nm) graphite particles on TES parameters of potassium nitrate was analyzed in this work. A novel technique of computer-aided cooling curve analysis was employed here to study the suitability of large inhomogeneous PCM samples. The addition of graphite micro- and nanoparticles reduced the solidification time of the PCM significantly enhancing the heat removal rates, in the first thermal cycle. The benefits of dispersing nanoparticles diminished in successive 10 thermal cycles, and its performance was comparable to the microparticle-embedded PCM thereafter. The decay of TES functionalities on thermal cycling is attributed to the agglomeration of nanoparticles which was observed in SEM images. The thermal diffusivity property of the PCM decreased with addition of graphite particles. With no considerable change in the cooling rates and a simultaneous decrease in thermal diffusivity, it is concluded that the addition of graphite particles increased the specific heat capacity of the PCM. It is also suggested that the additive concentration should not be greater than 0.1% by weight of the PCM sample. © 2017, ASM International.Item Assessment of Solidification Parameters of Salts and Metals for Thermal Energy Storage Applications Using IHCP-Energy Balance Combined Technique(Springer, 2018) Agarwala, S.; Prabhu, K.N.Solar energy storage technologies have proved to be promising in terms of providing uninterrupted power supply. The phase change materials (PCMs) with their higher heat storage capacity are more efficient than sensible heat storage materials. In this study, a new method for thermal analysis of PCM salts was proposed. The method was based on the estimation of heat flux at the mold–salt interface using solution to inverse heat conduction problem and characterizing the salt using a simplified energy balance method. It was advantageous over other computer-aided cooling curve analysis methods as it eliminated the use of curve fitting approach involved in baseline calculations. KNO3 and NaNO3 salts were used to validate this method. The solidification parameters like cooling rate, liquidus and solidus temperatures, solidification time and latent heat were assessed. The results of the analysis were in agreement with the data reported in the literature. © 2018, The Indian Institute of Metals - IIM.