Simulation Study On Thermoelectric Performance Of Double-skin Facade Photovoltaic Curtain Wall Building

With the development of society and the improvement of living quality requirements,the proportion of building energy consumption in the total energy consumption of the whole society is increasing.Due to the prominent influence of building envelope on building energy consumption,it is necessary for us to conduct energy-saving research on building envelope.Solar building integrated photovoltaic is the integration of photovoltaic modules into the building envelope structure,it is an efficient building envelope energy-saving technology,it greatly expands the utilization potential of photovoltaic modules,and helps to promote the development of building energy-saving technology.Help to achieve the goals of carbon peaking and carbon neutrality.Double-skin facade photovoltaic curtain wall is a new type of building photovoltaic integration technology,which uses photovoltaic module as double-layer skin curtain wall glass material to realize the organic combination of building exterior protection,photovoltaic power generation,thermal insulation,building appearance decoration and so on.Due to the complexity of double-skin photovoltaic curtain wall building structure,there are three heat transfer modes of solar radiation heat transfer,heat conduction and convective heat transfer in the cavity of double-skin facade photovoltaic curtain wall buildings.It is a complex task to accurately simulate and analyze the thermoelectric performance of double-skin facade photovoltaic curtain wall buildings.Existing studies have studied the thermoelectric performance of double-skin facade photovoltaic curtain wall buildings through theoretical or simulation methods,and have achieved many meaningful results,which play a certain reference role in the optimization design of double-skin fa(?)ade photovoltaic curtain wall buildings.However,in the existing research,the research content on the influence of variables such as different cavity spacing,ventilation speed,and ventilation mode on the thermoelectric performance of double-skin facade photovoltaic curtain wall buildings in cold regions is insufficient.Therefore,related research work needs to be further indepth.In this paper,the thermoelectric performance of double-skin facade photovoltaic curtain wall building is studied by means of simulation.In this paper,the building physical model of double-skin facade photovoltaic curtain wall is established.After the reliability of the model is verified by the experimental results,the thermoelectric performance of double-skin facade photovoltaic curtain wall is simulated.In this paper,taking copper indium gallium selenium(CIGS)double-layer photovoltaic curtain wall as the research object,the effects of different cavity spacing,ventilation wind speed and ventilation mode on the thermoelectric performance of double-layer photovoltaic curtain wall buildings are studied,and the thermoelectric performance of different building thermal design zones and double-skin facade photovoltaic curtain wall buildings are compared and analyzed.The conclusions of this paper are as follows:(1)In Taiyuan area,compared with the non-cavity building,the double-skin closed cavity,when the space between the cavity is 20 cm,35cm,50 cm,the building net energy consumption decreases 4580 kwh,4589kwh,4598 kwh respectively.Compared with the non-cavity building,the double-skin facade building shows the building energy-saving effect.Compared with the 20 cm closed cavity,continue to increase the cavity thickness,the building net energy consumption is reduced by less than 1%,and the energy saving effect is not obvious.Therefore,from the point of view of saving building consumables and building occupation area,it is recommended that the cavity spacing of double-skin facade photovoltaic curtain wall building should be 20 cm.In this paper,the distance between 20 cm cavities of double-skin photovoltaic curtain wall is studied.(2)In Taiyuan area,the double-skin facade photovoltaic curtain wall building is set with different ventilation wind speed conditions on the south-facing curtain wall,and the fresh air load of the building is the same under different ventilation wind speed conditions.Combined with the net energy consumption of the building,compared with the closed cavity,there are three ventilation modes: exhaust,external circulation,and internal circulation.The recommended ventilation speed is 0.4m/s,and it is not necessary to use a larger ventilation speed.In this paper,the ventilation wind speed of the double skin photovoltaic curtain wall is selected to be 0.4m/s for the subsequent research.(3)In Taiyuan area,the double-skin facade photovoltaic curtain wall building sets different ventilation modes in the south curtain wall,and the fresh air load of the building under different ventilation mode is the same.The building with combined ventilation has the lowest net energy consumption(the combined ventilation is the best ventilation mode for the cooling period and heating period of the whole year respectively),and the building with internal circulation ventilation has the highest net energy consumption.Compared with the internal circulation type,the net energy consumption of the combined ventilation building is reduced by 27.6%,and the net energy consumption of the exhaust ventilation building is reduced by 26.4%.Therefore,from the point of view of reducing the net energy consumption of the building,if a single ventilation mode is adopted,the priority ventilation grade is recommended as follows: exhaust air type,closed cavity,external circulation type and internal circulation type;if the combined ventilation mode is adopted,it is recommended that the combined ventilation mode is exhaust ventilation in winter heating period and external circulation ventilation in summer cooling period.(4)By comparing the energy consumption simulation results of eight representative cities with different building thermal design zones in China,the net energy consumption of buildings in Chengdu is the highest in hot summer and cold winter areas.Compared with Chengdu,the net energy consumption of buildings in Xining in the severe cold area is reduced by 1851 kwh,the net energy consumption of buildings in Taiyuan in the cold area is reduced by 1764 kwh,and the net energy consumption of buildings in Kunming in the mild area is reduced by 2120 kwh.And the net energy consumption in these three areas decreased significantly.Therefore,from the point of view of reducing the net energy consumption of buildings,two northwestern regions of Xining in the severe cold region and Taiyuan in the cold region,and Kunming in the mild area are suitable for the promotion and development of double-skin photovoltaic curtain wall buildings.(5)Ventilation is installed in the east,west and south of double-skin curtain wall buildings in the north and south of China(Taiyuan and Kunming),from the point of view of reducing the net energy consumption of the building.In Taiyuan,a cold area,if a single ventilation mode is adopted,the priority order of ventilation is recommended as follows: exhaust air type,closed cavity,external circulation type and internal circulation type;if combined ventilation mode is adopted,it is recommended that exhaust ventilation be used in winter heating period and external circulation ventilation in summer cooling period.In the mild area of Kunming,if a single ventilation mode is adopted,the priority order of ventilation is recommended as follows: exhaust air type,closed cavity,external circulation type and internal circulation type;if combined ventilation mode is adopted,it is recommended that exhaust ventilation be used in winter heating period and internal circulation ventilation in summer cooling period.The research results of this paper can provide scientific reference for the engineering design optimization of double-skin facade photovoltaic curtain wall buildings.