돈사 내부 열환경 분포의 공기연령 이론법 적용을 통한 전산유체역학 환기 예측 모델 개발
Development of CFD model for Predicting Ventilation Rate based on Age of Air Theory using Thermal Distribution Data in Pig House
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초록
The tracer gas method has an advantage that can estimate total and local ventilation rate by tracing air flow. However, the field measurement using tracer gas has disadvantages such as danger, inefficiency, and high cost. Therefore, the aim of this study was to evaluate ventilation rate in pig house by using the thermal distribution data rather than tracer gas. Especially, LMA (Local Mean Age), which is an index based on the age of air theory, was used to evaluate the ventilation rate in pig house. Firstly, the field experiment was conducted to measure micro-climate inside pig house, such as the air temperature, CO2 concentration and wind velocity. And then, LMA was calculated based on the decay of CO2 concentration and air temperature, respectively. This study compared between LMA determined by CO2 concentration and air temperature; the average error and root mean square error were 3.76 s and 5.34 s. From these results, it was determined that thermal distribution data could be used for estimation of LMA. Finally, CFD (Computational fluid dynamic) model was validated using LMA and wind velocity. The mesh size was designed to be 0.1 m based on the grid independence test, and the Standard k-ω model was eventually chosen as the proper turbulence model. The developed CFD model was highly appropriate for evaluating the ventilation rate in pig house.
Abstract
The tracer gas method has an advantage that can estimate total and local ventilation rate by tracing air flow. However, the field measurement using tracer gas has disadvantages such as danger, inefficiency, and high cost. Therefore, the aim of this study was to evaluate ventilation rate in pig house by using the thermal distribution data rather than tracer gas. Especially, LMA (Local Mean Age), which is an index based on the age of air theory, was used to evaluate the ventilation rate in pig house. Firstly, the field experiment was conducted to measure micro-climate inside pig house, such as the air temperature, CO2 concentration and wind velocity. And then, LMA was calculated based on the decay of CO2 concentration and air temperature, respectively. This study compared between LMA determined by CO2 concentration and air temperature; the average error and root mean square error were 3.76 s and 5.34 s. From these results, it was determined that thermal distribution data could be used for estimation of LMA. Finally, CFD (Computational fluid dynamic) model was validated using LMA and wind velocity. The mesh size was designed to be 0.1 m based on the grid independence test, and the Standard k-ω model was eventually chosen as the proper turbulence model. The developed CFD model was highly appropriate for evaluating the ventilation rate in pig house.
참고문헌 (17)
- De Jong, T., "Natural ventilation of large multi-span greenhouses: Proefschrift Wageningen", ~ (1990)
- Goedhart, M., "Methods and instruments for ventilation rate measurements III", International Symposium on Energy in Protected Cultivation, 148 (1983)
- Estimation of local mean ages of air in a room with multiple inlets, "Han, H. T.", The Society of Air-conditioning and Referigerating Engineers of Korea, 148~153 (2009)
- Hong, S. W., "Numerical simulation of ventilation efficiencies of naturally ventilated multi-span greenhouses in Korea", Transactions of the ASABE, 51(4), pp.1417~1432 (2008)
- Kwon, K. S., "Analysing ventilation efficiency in a test chamber using age-of-air concept and CFD technology", Biosystems Engineering, 110(4), pp.421~433 (2011)
- Liang, H., "Room Air Movement and Contaminant Transport", Ph.D., Department of Mechanical Engineering, pp.1994
- Ministry of Agriculture, Food and Rural Affairs, "Major statistics data of Agriculture, Food and Rural Affairs", 11-1543000-000128-10, ~ (2016)
- Infrared carbon dioxide gas analyser and its use in glasshouse research, "Morris, L. G.", National Institute of Agricultural Engineering, ~ (1954)
- Nederhoff, E., "A practical tracer gas method to determine ventilation in greenhouses", Journal of Agricultural Engineering Research, 31(4), pp.309~319 (1985)
- Okada, M., "Guide and data for greenhouse air conditioning", Journal of Agricultural Meteorology, 28(4), pp.223~230 (1973)
- Sandberg, M., "What is ventilation efficiency?", Building and environment, 16(2), pp.123~135 (1981)
- Sandberg, M., "The use of moments for assessing air quality in ventilated rooms", Building and environment, 18(4), pp.181~197 (1983)
- 서일환, "강제환기식 돈사의 환기 효율성 분석을 위한 CFD 모델 개발", 한국농공학회논문집, 50(1), pp.25~37 (2008), 한국농공학회
- Sherman, M. H., "Tracer-gas techniques for measuring ventilation in a single zone", Building and Environment, 25(4), pp.365~374 (1990)
- 송상현, "추적가스 실험을 통한 축사 내 질병 확산 분석", 한국농공학회논문집, 54(3), pp.37~45 (2012), 한국농공학회
- Whittle, R., "The climatology of glasshouses. II. Ventilation", Journal of Agricultural Engineering Research, (5), pp.36~41 (1960)
- The Study on heat exchanger with in-outlet fan for livestock building, "Yoo, J. C.", Konkuk univ: MIFAF, ~ (1997)