Performance Study On The Photovoltaic Trombe Wall With Catalytic Degradation Function

In order to reduce building energy consumption and indoor air pollution,the multifunctional Trombe wall has become one of the research hotspots of solar building integration technology.This paper proposed a novel photovoltaic Trombe wall with catalytic function—a partially covered photovoltaic-Trombe wall with bilateral thermocatalysis(PV-TC-TW).Then,based on the energy balance and mass balance,an unsteady lumped model for performance analysis and evaluation of photovoltaic Trombe walls with catalytic function was constructed.Combined with the existing reasearch of photovoltaic photocatalytic Trombe wall(PV-PC-TW),the reliability of proposed unsteady lumped model was fully verified,and the performance of PV-PC-TW and PV-TC-TW under different parameters and seasonal modes were studied.Finally,the performance of PV-PC-TW,PV-TC-TW,photocatalytic Trombe wall(PC-TW),thermocatalytic Trombe wall(TC-TW)and built-out photovoltaic Trombe wall(PV-TW)was compared.The main results are as follows:(1)The unsteady lumped model proposed in this paper is reliable.This model can obtain the performance and parameter influence law of the multifunctional Trombe wall easily and quickly,and enriches the methods for the performance analysis and evaluation of multifunctional Trombe wall.Based on this model,the performace of novel PV-TC-TW was studied.It is found that,when the photovoltaic cell coverage ratio is 0.6,the highest total efficiency of PV-TC-TW appears.By adding thermocatalytic coating on the back of the photovoltaic cell,the daily clean air volume of PV-TC-TW has been increased by 21.92%while having less impact on thermal and electrical performance.As the increase of the channel height or the decrease of the channel width,the outlet temperature of the PV-TC-TW rises,the clean air delivery rate and degradation efficiency increase.The reduction in the channel height or width can improve the thermal efficiency and total efficiency of the PV-TC-TW,but it has a smaller impact on the electrical efficiency.(2)In the winter heating mode,when the solar radiation intensity is low,the heating function and air purification function of PV-PC-TW and PV-TC-TW will fail.The lower the outdoor temperature,the shorter the effective operation time of PV-PC-TW and PV-TC-TW.Increasing the indoor temperature is not conducive to extending the effective operation time.For PV-PC-TW and PV-TC-TW,in winter heating mode,as the outdoor temperature decreases or the indoor temperature increases,the thermal efficiency decreases and the clean air delivery rate decreases.The increasing of indoor or outdoor temperature can improve the outlet temperature and the degradation efficiency,and decrease the total efficiency.In summer ventilation mode,the indoor and outdoor temperature have little effect on the ventilation performance and electrical performance of PV-PC-TW and PV-TC-TW.(3)By comparing the performance of PV-PC-TW,PV-TC-TW,PC-TW,TC-TW and built-out PV-TW,it is found that PV-TC-TW,which have indoor heating,air purification and photovoltaic power generation functions,has the highest degradation efficiency and total efficiency in the utilization of solar radiation among these multifunctional Trombe walls.When the solar radiation intensity is 753 W/m~2,and the channel height and width are 1 m and 0.05 m,respectively,the lowest degradation efficiency is 2.63%and the highest total efficiency is 72.53%.Therefore,the PV-TC-TW proposed in this paper has great application potential.