http://bura.brunel.ac.uk/handle/2438/62 2013-05-25T20:38:37Z 2013-05-25T20:38:37Z Gowreesunker, BL Tassou, SA http://bura.brunel.ac.uk/handle/2438/7444 2013-05-24T08:33:49Z 2013-01-01T00:00:00Z

Title: Evaluation of the energy impact of PCM tiles in an Airport Terminal Departure hall Authors: Gowreesunker, BL; Tassou, SA Abstract: In most past studies, passive PCM (phase change materials) systems have been tested for relatively small office spaces where the airflow is of minimal consequence in the overall energy consumption of the space. This paper on the other hand, reports on the application of PCM tiles on the floor of an Airport terminal space, similar to London Heathrow Terminal 5 departure hall, where in such large open spaces, the influence of airflow is crucial for the evaluation of the energy performance of AC units. In this paper, the evaluation of the energy performance of PCM tiles is obtained through a coupled simulation of TRNSYS and CFD. TRNSYS simulates the AC unit and PID control systems, while CFD is used to simulate the airflow and radiation inside the terminal space. The phase change process is simulated in CFD using an in-house developed model which considers hysteresis effects and the non-linear enthalpy-temperature relationship of PCMs. Although, a displacement ventilation (DV) system is actually employed at Heathrow Terminal 5, this study also compares the performance of the PCM tiles for a mixed ventilation (MV) system. Due to large computing times associated with CFD, discrete time-dependent scenarios under different UK weather conditions are used. The yearly energy demand is then determined through the heating/cooling degree day concept using base temperatures of 18 and 23 °C for HDD and CDD, respectively, similar to the comfort temperature range in the Terminal. The results show that the use of PCM tiles on the floor of the Terminal departure hall can lead to annual energy savings of around 3% for the DV system and 6% for the MV system, corresponding to 174 MWh/year and 379 MWh/year for the Terminal building. Description: Copyright @ 2013 CIBSE

2013-01-01T00:00:00Z Gowreesunker, BL Tassou, SA Kolokotroni, M http://bura.brunel.ac.uk/handle/2438/7443 2013-05-24T08:29:57Z 2013-01-01T00:00:00Z

Title: Coupled TRNSYS-CFD simulations evaluating the performance of PCM plate heat exchangers in an Airport Terminal building displacement conditioning system Authors: Gowreesunker, BL; Tassou, SA; Kolokotroni, M Abstract: This paper reports on the energy performance evaluation of a displacement ventilation (DV) system in an airport departure hall, with a conventional DV diffuser and a diffuser retrofitted with a phase change material storage heat exchanger (PCM-HX). A TRNSYS-CFD quasi-dynamic coupled simulation method was employed for the analysis, whereby TRNSYS® simulates the HVAC and PID control system and ANSYS FLUENT® is used to simulate the airflow inside the airport terminal space. The PCM-HX is also simulated in CFD, and is integrated into the overall model as a secondary coupled component in the TRNSYS interface. Different night charging strategies of the PCM-HX were investigated and compared with the conventional DV diffuser. The results show that: i) the displacement ventilation system is more efficient for cooling than heating a space; ii) the addition of a PCM-HX system reduces the heating energy requirements during the intermediate and summer periods for specific night charging strategies, whereas winter heating energy remains unaffected; iii) the PCM-HX reduces cooling energy requirements, and; iv) maximum energy savings of 34% are possible with the deployment of PCM-HX retrofitted DV diffuser. Description: This is the post-print version of the Article. The official published version can be accessed from the link below. Copyright @ 2013 Elsevier.

2013-01-01T00:00:00Z Edizel, O Evans, G Dong, H http://bura.brunel.ac.uk/handle/2438/7416 2013-05-21T13:05:30Z 2013-01-01T00:00:00Z

Title: Britain welcome's the world: Dressing up London Authors: Edizel, O; Evans, G; Dong, H Description: Copyright @ 2013 Routledge

2013-01-01T00:00:00Z Gowreesunker, BL Stankovic, SB Tassou, SA Kyriacou, PA http://bura.brunel.ac.uk/handle/2438/7368 2013-04-23T13:58:28Z 2013-01-01T00:00:00Z

Title: Experimental and numerical investigations of the optical and thermal aspects of a PCM-glazed unit Authors: Gowreesunker, BL; Stankovic, SB; Tassou, SA; Kyriacou, PA Abstract: This paper reports on the thermal and optical characterisation of PCM (Phase Change Material) RT27 using the T-history method and spectrophotometry principles, respectively, and the experimental and numerical performance evaluation of a PCM-Glazed unit. Various relationships describing the variations in the extinction, scattering and absorption coefficients within the phase change region were developed, and were validated in a numerical CFD model. The results show that: i) during rapid phase changes, the transmittance spectra from the PCM are unstable, while under stable conditions visible transmittance values of 90% and 40% are obtained for the liquid and phases, respectively; ii) the radiation scattering effects are dominant in the solid phase of the PCM, while radiation absorption dominates in the liquid phase; iii) the optical/radiation performance of PCM can be successfully modelled using the liquid fraction term as the main variable; iv) the addition of PCM improves the thermal mass of the unit during phase change, but risks of overheating may be a significant factor after the PCM has melted; v) although the day-lighting aspects of PCM-glazed units are favourable, the change in appearance as the PCM changes phase may be a limiting factor in PCM-glazed units. Description: This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2013 Elsevier.

2013-01-01T00:00:00Z