Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582496
Title: Melting and solidification models and thermal characteristics of microencapsulated phase change materials
Author: Yang, Jia
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 2013
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Abstract:
Microencapsulated phase change material (MPCM) as a new thermal energy storage material and a heat transfer medium have attracted considerable attention in the thermal energy storage field. Solidification and melting models of a single PCM particle are constructed in this thesis. An effective numerical method for the problem of a spherical particle with a moving boundary was developed and validated by an iterative analytical series solution. A new liquid-solid interface model was proposed for modelling the effect of binary phase composition on the solidification of an alloy and a mixture PCM particle based on solid fraction. A full two-phase melting model of differentlysized micro/nano particles was also built. The initial melting point of particles is defined and depends on the minimum melting temperature of particles measured by DSC, the particle size and the Gibbs-Thomson equation. The model can predict the melting time of micro-particles flowing in a heat transfer channel, which agrees with the group melting behaviour of MPCM as observed by experiments. A test rig was built to explore the melting heat transfer behaviour of microcapsule phase change slurry (MPCS) flowing through a circular tube for a given constant heat flux. DPNT06-0182 slurries were investigated on the test rig. The experimental results indicate that the flow rate is a key factor in determining heat transfer coefficients of slurries. For the same energy efficiency, and in the situation of low flow rate and phase change, the pressure drop and local heat transfer coefficients of 10% DPNT slurry are lower compared with water, but the most heat energy is stored during the passage through the heated test section. However, in the case of high flow rates and no phase change, the local heat transfer coefficients of 10% DPNT slurry are higher with comparison to water under turbulent flows.
Supervisor: Not available Sponsor: Engineering and Physical Sciences Research Council (EPSRC) ; University of Warwick
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.582496  DOI: Not available
Keywords: QC Physics ; TA Engineering (General). Civil engineering (General) ; TS Manufactures
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