Study On Thermal And Electrical Performance Of Semi-transparent Photovoltaic Window With Different Air Distribution Indoor

Energy saving,emission reduction and development utilization of new resources have become the key to alleviate energy crisis,gradually.With the development of building integrated photovoltaic(BIPV),a variety of photovoltaic system has arisen.The semi-transparent photovoltaic window will hold great development prospects,which is a new BIPV mode.On the one hand,that can make full use of solar energy for producing power;on the other hand,that can reduce air conditioning load of building and improve the level of window energy consumption.Environment indoor and outdoor has an effect on the thermal and electrical performance of the semi-transparent photovoltaic window significantly and directly.However,Most of studies focus on the impact of environment outdoor,the studies of thermal and electrical performance of the semi-transparent photovoltaic window with different air distribution indoor is still rare.So it is necessary to analysis thermal and electrical performance of the photovoltaic window under different characterization of air distribution indoor,deeply.These research results of the paper will have an important theoretical and practical significance for collaborative design of photovoltaic window system and air conditioning system of building.First of on,about the characterization of air temperature distribution indoor under two kinds of typical air distribution indoor: Stratified Air Distribution System(STRAD)and Mixing Ventilation System(MV),a two-dimensional steady-state heat transfer model of the single-glazed semi-transparent photovoltaic(PV)window integrated with amorphous silicon(a-Si)is established in this paper,then we make the numerical solution with Fortran software,and its accuracy is verified by comparison of measured and simulated photovoltaic window temperature.Secondly,the heat transfer performance of the semi-transparent single-glazed photovoltaic window integrated with a-Si is investigated with Stratified Air Distribution System and Mixing Ventilation System indoor using the numerical simulation method in this paper.Then preliminary optimization study on operational states and heat transfer performance of photovoltaic window is carried out for different supply air conditions.There are some research results as follows: 1)there is a remarkable temperature gradient distribution in the vertical facade of PV window for Stratified Air Distribution System,and the temperature gradient is about 2.2 ℃/m;however,with the Mixing Ventilation System,the surface temperature of photovoltaic window is increasing significantly along the flow of supply air;2)in these cases,the operating temperature of photovoltaic modules is decreasing with increasing supply air velocity,and the operation condition of photovoltaic window system is improved,but the effect is not obvious;3)increasing supply air velocity is not benefit for reducing heat gain from PV windows in summer season.Considering the difference of air conditioning system and air distribution characterization indoor,also,combining with the characterization of air conditioning load under different seasons,it is suggested that different optimization measures for the thermal performance of photovoltaic window system should be adopted.In addition,the thermal and electrical performance of the single and double-glazed natural convection photovoltaic window is investigated with Stratified Air Distribution System and Mixing Ventilation System indoor comparatively.The results show that:1)the construction of photovoltaic window and air conditioning system have a slight effect on power output,but that have an effect on heat gain of photovoltaic window obviously.2)compared to single-glazed photovoltaic window,the double-glazed natural convection photovoltaic window with the STRAD and the MV can improve the thermal and electrical performance of the photovoltaic window system about 54.4% and 52.6%,respectively;and compared to the MV,the thermal and electrical performance of the single and double-glazed photovoltaic window under the STRAD is improved about 11.2% and 14.6%,respectively.Finally,the thermal and electrical comprehensive performance of photovoltaic window has been regarded as the evaluation index for performance of photovoltaic window in this paper,also,a optimization study of the width of ventilation cavity of double-glazed natural convection photovoltaic window under the STRAD is studied.The result shows that the optimal effect of saving-energy for the double-glazed ventilated photovoltaic window is obtained when the width of ventilation cavity is 35 mm.