Numerical and Experimental Analysis of Heat Transfer and Airflow in Double Skin Facades with Integrated amorphous silicon PV Cells.

摘要

A double skin facade (DSF) is a strategy utilized for improving building performance through using an inner and outer wall on a building with a cavity created between two walls. If photovoltaic modules or solar cells are integrated with a DSF, this facade becomes a building-integrated photovoltaic (BIPV) facade.;This thesis presents a numerical and experimental analysis of heat transfer and airflow in DSF system with integration of a-Si PV cells, which generates both electricity and providing day lighting. A 2D numerical model is developed to explore the thermal behaviour and fluid dynamics in the air cavity of the DSF system for both open and closed inlet and outlet operational modes. The combined radiation and convection heat transfer in the air cavity are analyzed in detail in this thesis.;Steady natural convective airflow in a novel type glazing system with integrated semi-transparent photovoltaic (PV) cells has been analyzed numerically using a stream function vorticity formulation. The effects of Rayleigh numbers on airflow patterns and local heat transfer coefficients on vertical glazing surfaces are investigated for Rayleigh numbers in the range of 103 ≤ Ra ≤ 2 x 105. Good agreement for the Nusselt numbers was observed between numerical simulation results in this thesis and those of earlier experimental and theoretical results available from the literature.;Various turbulence models (RNG kappa -- epsilon model, Standard kappa -- epsilon model, Realizable kappa -- epsilon model) were employed and velocity and temperature profiles predicted were compared and discussed in this thesis. A test rig was developed and calibrated for this study. An experimental study was carried out and predicted results were then compared with experimental data to evaluate the numerical simulation accuracy. Experimental measurements taken in the full scale indoor test facility are in good agreement with predicted results. The experimental results indicated that the inside air temperature for PV DSF system is quite lower than temperature in conventional facade with internal curtain for shading purposes.;The results show that heat transfer and airflow in the cavity is a complex problem, which could influence the thermal performance of the PV DSF system. The results also show this novel glazing system type developed in the current thesis could not only generate electricity but also achieve potential energy savings by reducing the air conditioning cooling load when applied in subtropical climatic conditions and simultaneously provide visual comfort for occupants in the indoor environment.