Theoretical And Experimental Performance Analysis Of A Photocatalytic-Thermal-Catalytic-Photovoltaic-Trombe Wall System Integrated With Compound Parabolic Concentrator

Solar energy is a kind of clean renewable energy,which is inexhaustible.Wherever the sun shines,solar energy can be directly developed and utilized.Trombe wall is one of the ways to use solar energy to reduce building energy consumption.In order to make full use of the solar energy projected on the Trombe wall,a photocatalytic-thermal-catalytic-photovoltaic-Trombe wall system integrated with compound parabolic concentrator（CPC）is proposed.It makes full use of outdoor solar radiation and realizes multiple functions of heating and ventilation,formaldehyde degradation and photovoltaic power generation.It effectively reduces building energy consumption and improves indoor air quality,which has great potential application value.In this paper,the optical simulation software Tracepro was used to study the focusing characteristics of double compound parabolic concentrator（CPC）with different truncation ratio.Considering the focusing performance and material cost,after focusing,the irradiation intensity of 2 times 1/3 truncated compound parabolic concentrator（CPC）was not much lower than that of 2 times nontruncated compound parabolic concentrator（CPC）,and the maximum irradiation intensity was slightly lower,but a certain amount of material was saved.Although the material of 2 times 2/3 truncated compound parabolic concentrator（CPC）was greatly saved,after focusing,the irradiation intensity was significantly lower than that of 2 times nontruncated compound parabolic concentrator（CPC）.In the case of little impact on the focusing effect,the cost was reduced and the cost performance was improved by shortening the concentrator with a certain height at the front end.Therefore,2 times 1/3 truncated compound parabolic concentrator（CPC）was selected to be applied to the Trombe wall.Based on the classical Trombe wall,we coated the inner paraboloid of compound parabolic concentrator（CPC）and the back of photovoltaic panels with photocatalyst Ti O₂and thermal catalyst Mn O_x-Ce O₂ respectively.The photovoltaic panels combined with compound parabolic concentrator（CPC）were placed in the middle of the flow channel.The original flow channel was divided into outer photocatalytic flow channel and inner thermal catalytic flow channel.The experimental detection platform of the system was built,and the whole day operation experiment was carried out.The experimental results showed that under the conditions of daily average solar irradiation intensity of 814.53W/m2and daily average ultraviolet（UV）irradiation intensity of 3.48 m W/cm2,the daily average thermal efficiency of the system and the single pass rate of formaldehyde of the system were 0.32 and 0.25-0.46,respectively;the daily average thermal efficiency and the single pass rate of formaldehyde in the photocatalytic flow channel were 0.36 and0.25-0.56,respectively;the daily average thermal efficiency and the single pass rate of formaldehyde in the thermal catalytic flow channel were 0.26 and 0.18-0.38,respectively;the daily average output power of the system was 11.33 W and the daily average photoelectric conversion efficiency of the system was 6.68%,up to 10.16%.In this paper,the photocatalytic-thermal-catalytic-photovoltaic-Trombe wall system integrated with compound parabolic concentrator（CPC）was theoretically simulated,and the effects of different parameters on the performance of the system were analyzed.The simulation results showed that with the greater the solar irradiation intensity and the lower the air inlet temperature,the instantaneous thermal efficiencies of the photocatalytic channel and the thermal catalytic channel and the photoelectric conversion efficiency of the photocatalytic-thermal-catalytic-photovoltaic-Trombe wall system integrated with compound parabolic concentrator（CPC）were higher;with the lower the formaldehyde inlet concentration,the greater the clean air volume of Trombe wall and the smaller the ventilation times,the formaldehyde degradation effect of the room equipped with the photocatalytic-thermal-catalytic-photovoltaic-Trombe wall system integrated with compound parabolic concentrator（CPC）was better and the indoor formaldehyde concentration under steady state was lower.