Application Of Photovoltaic Curtain Wall In Office Building

Under the dual pressure of energy crisis and environmental pollution,it is urgent to research and develop new energy to solve the future human demand for energy.Among them,solar photovoltaic directly uses the main renewable energy on the earth-solar energy,which can generate clean electricity directly and silently,and is recognized as the most promising new energy technology in the world.In recent years,solar photovoltaic panels are more and more integrated into the building envelope.As a part of the building envelope,it can not only create clean power,but also play a role in insulation in winter.Generally,there is a cavity between the photovoltaic curtain wall and the external wall of the building.The geometry of the cavity not only affects the power generation efficiency and service life of the photovoltaic cell,but also affects the heat gain of the building envelope,and then affects the air conditioning load of the building.In this paper,taking Shenyang as an example,the PV wall is simulated by CFD in the form of natural ventilation,external circulation and internal circulation.The temperature distribution characteristics of PV panel,external surface of building wall and air inside the cavity,the average velocity of air at the air outlet and natural ventilation are analyzed under different cavity height and width Change.In addition,after considering the power generation efficiency of photovoltaic panels,the external natural ventilation and heat dissipation capacity,and the internal circulation,the reasonable ventilation cavity geometry is determined.The existence of photovoltaic curtain wall and cavity has changed the heat transfer mode of the traditional building exterior wall,on the one hand,it has blocked the building exterior wall from receiving the solar radiation heat,on the other hand,it has also blocked the convection and radiation heat transfer between the building exterior wall and the external environment.In order to analyze the influence of photovoltaic curtain wall and cavity on building energy consumption,the common office building model and photovoltaic office building model with photovoltaic panels laid outside the south wall of the same office building are established respectively.In the construction of photovoltaic building model,the form of natural ventilation and heat dissipation of ventilation cavity is adopted in summer.Considering the low outdoor temperature in winter in Shenyang area,the way of circulation and heat extraction in the cavity is not easy to realize,so the closed cavity passive heat preservation form is adopted in winter.The energy consumption simulation software Energy Plus is used to simulate the energy consumption of ordinary office buildings and photovoltaic office buildings with cavities.The influence of the structure of photovoltaic curtain wall+cavity on the external surface temperature of the wall,indoor cooling and heating load is analyzed.The monocrystalline silicon material is used as the cell module of the photovoltaic curtain wall.In the process of photovoltaic power generation simulation,thetypical solar photovoltaic power generation in winter and summer of the photovoltaic curtain wall is calculated by using the characteristics that the conversion efficiency of monocrystalline silicon battery changes with the temperature,and the annual photovoltaic curtain wall power generation is output.Finally,based on the established office building research model,the comprehensive benefits of photovoltaic curtain wall can be analyzed,and the investment payback period of photovoltaic curtain wall is 8.25 years,and the life cycle of photovoltaic module is generally25 years,which has investment value;for the building users,the existence of photovoltaic curtain wall saves the annual heating and air conditioning costs by 1023.21 yuan,with considerable economy;in the life cycle,the investment payback period of photovoltaic curtain wall is 8.25 years Compared with conventional thermal power generation,photovoltaic curtain wall power generation can reduce emissions of CO2,SO2 and NOx by394.50 t,3.50 t and 1.00 t,which has significant energy conservation and emission reduction benefits.