Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Gumtapure, V.Subject: search.filters.subject.Thermal conductivity

Search Results

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    A review on thermal energy storage using composite phase change materials
    (Bentham Science Publishers, 2018) Chavan, S.; Gumtapure, V.; Arumuga Perumal, D.A.
    Background: This paper intends to provide the elementary understanding about the development of thermal energy storage systems. Reviews of storage system performance are carried out from various characterization studies, experimental work, numerical investigations and patents. Several techniques employed to enhance the thermal performance have been reviewed and discussed. Composite phase change materials are the best alternative to achieve the cost feasibility in thermal energy storage systems without compromising the storage capacity. Objective: The purpose of this study is to give an outline and history of the thermal energy storage systems and enlighten the techniques used for storage density enhancement without significant modifications in the design. Methods: In this study, three methods such as, characterization studies, experimental work, numerical investigations and patents. It also addresses many research articles and recent patents on the thermal storage systems, various techniques adopted and applications of such systems. Results: Composite phase change materials are the best alternative to achieve the cost feasibility in thermal energy storage systems without compromising the storage capacity. Carbon based nanoparticles show excellent properties in the composite phase change materials. Conclusion: Composite phase change materials have greater potential for thermal energy storage applications and especially carbon-based nanoparticles like graphene, graphene oxide, carbon nanotubes, fullerene, graphite, graphite oxide, extracted graphite etc., are greatly enhancing the thermo-physical properties of composite phase change materials. Combination of paraffin-based phase change materials and carbon-based nanoparticles can be used for the future thermal energy storage applications. © 2018 Bentham Science Publishers.
  • No Thumbnail Available
    Item
    Characterization of linear low-density polyethylene with graphene as thermal energy storage material
    (Institute of Physics Publishing helen.craven@iop.org, 2019) Chavan, S.; Gumtapure, V.; Arumuga Perumal, D.A.
    In this work authors reported the preparation and characterization of composite phase change material (CPCM) using the direct-synthesis method by blending the Linear low-density polyethylene (LLDPE) with Carboxyl Functionalized Graphene (f-Gr). LLDPE is selected as base material and f-Gr is dispersed into three different concentrations 1.0, 3.0, and 5.0 wt% and referred as CPCM-1, CPCM-2 and CPCM-3 respectively. Experimental analysis is carried out through Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Differential scanning calorimeter (DSC). The preset study assesses the influences of nanoparticle concentration on thermophysical properties, thermal performance and thermal storage characteristics of CPCMs. Results show that addition of f-Gr improves the thermal conductivity and latent heat of fusion of LLDPE. However, f-Gr slightly reduces the melting temperature and decreased the crystallization temperature. Therefore, this study reveals that f-Gr, addition to LLDPE has substantial potential for improving the thermal energy storage performance. © 2019 IOP Publishing Ltd.
  • No Thumbnail Available
    Item
    Thermal property study of fatty acid mixture as bio-phase change material for solar thermal energy storage usage in domestic hot water application
    (Elsevier Ltd, 2019) B.V., R.M.; Gumtapure, V.
    For the correct design, simulation and specific application of the latent heat thermal energy storage (LHTES) system, detailed evaluation of phase change material (PCM) properties are essential. Present study aims to analyze the thermal and volume dependent behavior of available organic Bio-PCM OM55, using conventional thermal gravimetric analyzer (TGA), thermal constant analyzer (TCA), differential scanning calorimeter (DSC) and in-house T-history method (THM). Execution of the mentioned thermal analysis outcome with significant information of OM55. TGA shows that OM55 is thermally stable within the operating temperature 45–60 °C, because the maximum permissible degradation temperature 154.6 °C is much higher than operating temperature range. The OM55 has considerable thermal conductivity compared to the existing PCM, which is already used in domestic solar water heating (DSWH) applications. The evaluation of transition temperature, isothermal enthalpy, and specific heat by THM are well compared with the DSC analysis. Comparison of DSC and THM analysis showed that the behavior of OM55 is volume independent. The overall study concluded that OM55 is a potential Bio-PCM. However, for the optimum amount of energy storage and discharge in OM55, it is recommended to operate the LHTES unit over a temperature range between 46–59 °C for domestic hot water application. © 2019 Elsevier Ltd
  • No Thumbnail Available
    Item
    Thermo-physical analysis of natural shellac wax as novel bio-phase change material for thermal energy storage applications
    (Elsevier Ltd, 2020) B.V., B.V.; Gumtapure, V.
    The high energy density of latent heat storage makes it more competent than other types of thermal energy storage (TES) systems. Studying thermophysical and rheological properties of phase change material (PCM) is required for effective storage design, simulation, and applications. Bio-based PCM (BPCM) is a renewable and eco-friendly option for commercial paraffin-based PCMs. This study intends to characterize the shellac wax using the conventional and non-conventional approach as novel BPCM. Analysis of Fourier transforms infrared spectrophotometer (FTIR) indicates that shellac wax has aliphatic hydrocarbons, carboxylic acid, alcohol, and esters functional group. Thermogravimetric analysis (TGA) shows shellac wax has no mass change for operating temperature range (50–85 °C). Differential scanning calorimetry (DSC) analysis reported enthalpy of melting and crystallization as 148 kJ/kg and 161 kJ/kg, respectively. The crystallization enthalpy measured in the T-history method (THM) is 210.5 kJ/kg. However, DSC analysis of sample undergone 0,100,200 and 300 thermal cycle shows no significant change in thermal properties. Other properties like thermal conductivity, density, specific heat and viscosity are comparable to the present PCM used in storage applications. The overall study outcome that shellac wax is thermally stable and is potential BPCM for the TES application like solar desalination, district heating, waste heat recovery and solar cooking. © 2020 Elsevier Ltd