Browsing by Author "Shire, G.S.F"

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    Characterizing Micro-channel Absorber Plates for Building Integrated Solar Thermal Collectors
    (Sage, 2018-06-12) Oyinlola, M. A.; Shire, G.S.F
    This paper discusses the characterisation of micro-channel absorber plates for Compact Flat Plate solar thermal collectors, which are suitable for Building Integration. Experimental and computational studies were carried out at typical operating conditions for flat plate solar collectors. Three-dimensional numerical analysis using commercial CFD package, Ansys CFX, showed that heat transfer occurred on only three surfaces of the channel and there was a peripheral variation of the heat flux density. It was also observed that axial thermal conduction could modify the surface boundary at the inlet and outlet, however, the middle section of the channel could be approximated as a rectangular channel with three walls transferring heat under a H1 boundary condition. Experimental studies were used to estimate the standard parameters for predicting performance of the flat plate collectors, which indicated promising performance results. The collector flow factor F” and the heat removal factor could be improved by increasing the collector capacitance rate; this can be achieved by increasing the mass flow rate per collector area m ̇/A_c, as well as reducing the overall heat loss, UL . This analysis is important for optimizing design and operating parameters, especially to minimize temperature gradient in the transverse and longitudinal directions.
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    Parametric analysis of influencing factors in Phase Change Material Wallboard (PCMW)
    (Elsevier, 2014-01-25) Zhou, D.; Shire, G.S.F; Tian, Y.
    Incorporating Phase Change Materials (PCMs) into traditional building structures has been considered as an effective way to reduce the mismatch between energy supply and demand and in turn to minimise energy consumption (cooling/heating energy). For building applications, Phase Change Material Wallboards (PCMWs) are of particular interest due to their easy installation to existing buildings for refurbishment. Both interior and exterior PCMWs are investigated in this paper, with a numerical study examining the effects of wallboard thermal properties on its thermal performance. These influencing factors include melting temperature, melting range, latent heat, thermal conductivity and surface heat transfer coefficient. An effective heat capacity model is adopted to consider latent heat with the model validated by an experiment. Inner surface temperature and diurnal energy storage are chosen as the evaluation criteria when comparing the thermal performance between different PCMWs. By analysing the effects of influencing factors on the system thermal performance, this study serves as a useful guide for selection of PCMs in energy-efficient buildings.