间接蒸发冷却新风机组净化室内PM2.5特性

为有效降低室内PM2.5,指导间接蒸发冷却新风机组的设计选型,推导了新风机组净化效力和净化能效评价指标的数学表达式,并利用自行研制的间接蒸发冷却新风机组,分析了2种过滤器在不同运行工况下净化PM2.5的特性。结果表明,MERV 7+16和MERV 7+13的计数效率均随颗粒物粒径增加而提高,且前者的计数效率高于后者;由于滤材的不同,MERV 7+16的初阻力更小。MERV 7+16的渗透系数更小,其净化效力也要大于MERV 7+13;由于PM10在室内的自然沉降作用更显著,过滤器对PM10的净化效力明显大于PM2.5和PM1。将室内新风负荷作为新风机组能耗的一部分,在对比天津和南宁地区新风机组的净化能效时发现,由于两地区冬季室外温度存在明显差异,导致处于天津地区的新风机组若要在冬季获得同等的洁净空气量,需付出更多的能耗代价。

Research on indoor PM2.5 control perform of indirect evaporative cooling fresh air unit

The given paper intends to contribute to the study of the filtration unit-a novel IEC fresh air ventilator.As is well known,the indirect evaporative cooling(IEC)technique is by nature a kind of ancient solution to the energy saving air cooling device,whose advantage lies in the latent heat of water vaporization,whereas the filtration performance of the indoor PM2.5by this IEC fresh air ventilator has to be theoretically investigated and employed experimentally with the different filter materials for its practical applications.What is more,the filtration effectiveness and clean energy efficiency of the afforementioned device can further be reinvented and perfected to estimate the filtration effect based on the original mathematical model,so as to increase its accounting efficiencies of MERV 7+16 and MERV 7+13 by increasing its particle size.Moreover,in comparison with the efficiency to be accounted between MERV 7+16 and MERV 7+13,it has been found that the former should be made much higher than the latter.For,the 2 different filters have been made of different materials and shapes,so as to render its permeability and airflow resistance quite different,thus,rendering the airflow resistance to the initial pressure of MERV 7+16 lower than that of MERV 7+13,though its filtration efficiency has been made lower with the increase of the filters’penetration efficiency.On the contrary,the penetration efficiency of MERV 7+16 turns to be noticeably smaller than that of MERV 7+13,so that the filtration efficiency of MERV 7+16 has been made much higher.Thus,specifically speaking,the medium sized particles(PM2.5and PM1)and the big sized ones(PM10),and the natural decay rates may turn to be about 1 h-1and about 10 h-1,respectively.Just for this reason,the filtration efficiency of the filters of PM10has been raised much higher than that on PM2.5and PM1.Therefore,in calculating the cleaning energy efficiency of the IEC fresh air ventilator with filters of different types under the typical working conditions in Tianjin and Nanjing,it would be necessary to consume 2 parts of energy,that is,the electrical power consumption of ventilation and filtration system and the electrical power consumed by the fresh air introduced.Thus,the results of our investigation demonstrate that,in winter days,since the outside temperatures between Tianjin and Nanning are quite different,the energy consumption of the fresh air ventilator in Tianjin ought naturally to be a lot greater to achieve the same rate of clean air delivery in Nanning.Thus,it can be seen that the conclusion made in this paper can help to lay a reliable foundation for the IEC technique to promote its engineering application.