CAJ | 학술논문

为优化挡流板形式以提高营养液循环利用前的杀菌效率，该文提出了2孔-圆环、2孔、4孔-圆环、4孔、4孔-4孔交错单一布置型和组合型5种不同的消毒仪内部挡流板改进方案，并利用计算流体力学（computational fluid dynamics， CFD）进行数值模拟和分析，结合径向辐射模型计算得出病菌在不同消毒仪内运动过程中受到的辐射剂量值。结果表明加装4孔型挡流板时，颗粒在消毒仪内绕流过程中受到的辐射剂量最小值、平均值比改进前的截去挡流板顶端或底端部分型挡流板分别提高33.4%、4.2%，变异系数减小0.07。与其他改进方案相比，4孔型对应的颗粒辐射剂量最低值最大，变异系数最小，分布更加集中合理，表明4孔型挡流板优于改进前和其他几种改进方案。该文结果可为优化消毒仪内部结构和提高杀菌效果提供理论依据。
위우화당류판형식이제고영양액순배이용전적살균효솔，해문제출료2공-원배、2공、4공-원배、4공、4공-4공교착단일포치형화조합형5충불동적소독의내부당류판개진방안，병이용계산류체역학（computational fluid dynamics， CFD）진행수치모의화분석，결합경향복사모형계산득출병균재불동소독의내운동과정중수도적복사제량치。결과표명가장4공형당류판시，과립재소독의내요류과정중수도적복사제량최소치、평균치비개진전적절거당류판정단혹저단부분형당류판분별제고33.4%、4.2%，변이계수감소0.07。여기타개진방안상비，4공형대응적과립복사제량최저치최대，변이계수최소，분포경가집중합리，표명4공형당류판우우개진전화기타궤충개진방안。해문결과가위우화소독의내부결구화제고살균효과제공이론의거。
Nutrient solution recycling has become one of the essential techniques of soilless cultivation. But nutrient solutions are susceptible to be polluted by infectious diseases during the recycling process, so it is needed to disinfect nutrient solutions before recycling use. Compared to other disinfection methods of common nutrient solutions, ultraviolet (UV) disinfection has many advantages, such as high efficiency, low cost, not changing the physical and chemical properties of nutrient solutions, so UV disinfection is an environment-friendly technology of nutrient solution treatment.In general, experimental research and numerical simulation are the most common methods of UV disinfection. Although experimental results of the performance of UV disinfection reactor are credible, direct measurement is difficult and costly and thus seldom done. On the other hand, one can use numerical simulation techniques to model the UV disinfection. Computational fluid dynamics (CFD) has been widely used for simulating the UV disinfection. In previous studies, some researchers analyzed the performance of small-scale horizontal UV disinfection reactors with different flow baffle numbers and flow areas. They designed an alternately arranged flat-type flow baffle and analyzed the performance of the UV disinfection device for nutrient solutions using the CFD simulations and the measurements of biological bacterial disinfection. However, the effects of different flow baffle types on the performance of the UV disinfection reactor have seldom been investigated. In this study, we designed 5 different flow baffle types of the UV disinfection reactor. The main objectives were to increase disinfection efficiency by optimizing the flow baffle arrangement and to test the performance of the UV disinfection reactor with different flow baffle types. The 5 different flow baffle types were proposed: 2 circular channels and annulus alternation, 2 circular channels, 4 circular channels and annulus alternation, staggered arrangement of 4 circular channels and 4 circular channels, and 4 circular channels. Using the discrete phase model (DPM) of the software ANSYS Fluent 14.0, we simulated the motion of Tomato Fusarium oxysporum particle in nutrient solution in the UV disinfection reactors with different flow baffle types, and the inlet flow rate was set to 900 L/h. The UV irradiation dose was calculated and compared for different flow baffle types using the radial radiation model (RRM). The result indicated that for the flow baffle type with 4 circular channels, the lowest and average radiation doses received by the Tomato Fusarium oxysporum particle increased by 33.4% and 4.2% respectively, and the coefficient of variation (CV) decreased by 0.07, compared to the original type. Compared to other flow baffle types, the lowest radiation dose and the CV value for the type with 4 circular channels were respectively significantly greater and less. These results suggested that the UV disinfection reactor of the flow baffle type with 4 circular channels was the best scheme. Furthermore, the simulation results suggested that the combined baffle arrangement had a higher disinfection effect than the single baffle for 2 circular channels, but the combined baffle arrangement had a lower disinfection effect than the single baffle for 4 circular channels. Therefore, these results can provide a theoretical basis for optimizing the internal structure and enhancing the performance of the UV disinfection reactor.