간척지 인근 농경지에서의 비산 및 부유먼지 확산 모니터링(I) : 군산 모니터링

황현섭,이인복,신명호,홍세운,서일환,유재인,이승기,Hwang, H.S.,Lee, I.B.,Shim, M.H.,Hong, S.W.,Seo, I.H.,Ryu, J.I.,Lee, S.K. 한국농공학회 2008 한국농공학회논문집 Vol.50 No.4

A study on fugitive dust dispersion was conducted at Saemanguem reclaimed area located at the west coastal area of Jeon-buk Province Total reclaimed area is 40,100ha developed by building a 33km long sea dike through Gunsan, Gimje, and Buan. (Land: 28,300ha, Fresh Water Lake: 11,800ha) After this area was completely reclaimed in 2006, there has been high possibility of dust generation and dispersion to the neighboring area. The dust generated at the reclaimed land was composed mainly of minerals with high salinity, and it could make harmful effect on crop production as well on to human's health such as eye irritation and respiratory disease. Especially, when those aerosol particles are reached on the leaves of farm crops, the photosynthesis and respiration of the plants can be under restraint resulting in the decrease of agricultural productivity of the nearby farm areas. Furthermore, highly concentrated salty particles can directly damage the leaf cells. In this study, field experiment has been conducted to regularly measure the locally suspended dust particles and analyze how they were dispersed to the neighboring areas. The collected dust particles were analyzed to examine theirs sizes, concentrations, and components. The SPSS statistical program was also used to separate the dust concentration generated by the reclaimed land from the total dust concentration measured at the measuring locations.

BES 기법을 이용한 자연환기식 육계사의 난방에너지 분석

홍세운,이인복,홍희기,서일환,황현섭,유재인,권경석,하태환,김기성,Hong, S.W.,Lee, I.B.,Hong, H.K.,Seo, I.H.,Hwang, H.S.,Bitog, J.P.,Yoo, J.I.,Kwon, K.S.,Ha, T.H.,Kim, K.S. 한국농공학회 2008 한국농공학회논문집 Vol.50 No.1

Most of the broiler houses in Korea have experienced problems on controlling the environmental conditions such as suitability, stability and uniformity of rearing condition inside the broiler house. It is very critical which if not properly controlled, would cause serious stress on the chickens. It is therefore urgent to develop optimum designs of naturally ventilated broiler house which is appropriate to the four seasons of Korea. Field experiment for this matter is very difficult to conduct due to the unpredictable and uncontrollable weather condition. In this study, the heating load of a naturally ventilated broiler house was calculated using TRANSYS 15 BES program while internal climate and thermal condition were computed using Fluent 6.2. The computed resulted of the conventional ventilation system (A) and upgraded ventilation system (B) (Seo et al, 2007) were compared with each other for cold season. The results of the Building Energy Simulation(BES) indicated that the system B, the upgraded ventilation system made 8% lower total heating load and 47% lower at only the broiler zone compared to the conventional broiler house. Considering the entire broiler house, the existence of middle ceiling made the heating energy 11% lower required than without middle ceiling. Accordingly, the system B with middle ceiling was found to save heating energy by 20% in average. This study showed that the BES program can be a very powerful to effectively compute the energy loads of agricultural building while the energy load is very close related to ventilation efficiency.

새만금 지역 간척지 및 인근 농경지에서의 비산 및 부유먼지의 지역별, 시기별 모니터링

황현섭,이인복,신명호,이광야,홍세운,서일환,유재인,권경석,김용희,Hwang, H.S.,Lee, I.B.,Shin, M.H.,Lee, G.Y.,Hong, S.W.,Seo, I.H.,Yoo, J.I.,Bitog, J.P.,Kwon, K.W.,Kim, Y.H. 한국농공학회 2009 한국농공학회논문집 Vol.51 No.5

A study on fugitive dusts was conducted at Saemangeum reclaimed land and the neighboring farm located at the west coast of Korea. After the area was completely reclaimed in 2006, halophyte plants and several windbreak systems were installed. The distributions of suspended dust particle was regularly measured through field experiment. The size of dust source area was also analyzed periodically and then it was determined to be in the following order: Buan > Gimje > Gunsan. The suspended dust which were dispersed to the neighboring areas were significantly affected by the size of the soil particles, wind velocity and wind direction. The results of Big Spring Number Eight (BSNE) experiments also showed that the concentration of the fugitive dust generated from the reclaimed land was reduced remarkably by the presence of halophyte plants. Recently, in 2008, the measured dust concentration rate was decreased by an average of 30.6%. The average dust concentration is expected to decrease further as more areas are being covered by halophyte plants.

생물생산시설 및 환경공학 분야 : 비육돈 수송차 적재함 개량(2) -적재함 형식별 수송중 온습도 변화 및 돼지 반응-

유병기 ( B. K. Yu ),오권영 ( K. Y. Oh ),이성현 ( S. H. Lee ),최광재 ( K. J. Choe ),이인복 ( I. B. Lee ),박환중 ( H. J. Park ),오형규 ( H. G. Oh ) 한국농업기계학회 2004 한국농업기계학회 학술발표논문집 Vol.9 No.2

전산유체역학을 이용한 미세조류 배양용 광생물반응기의 정량적 평가 방안

서일환 ( I. -h. Seo ),이인복 ( I. -b Lee ) 한국농공학회 2010 한국농공학회 학술대회초록집 Vol.2010 No.-

Renewable energy has been interested due to the fossil energy depletion and the carbon dioxide reduction. Bio-diesel is one of the most desirable renewable energy because it can alternate the diesel from petroleum directly. However, the bio-diesel using soybean, canola, corn crop, etc. can be confronted with food consumption. Because a microalgae has higher oil lipid contents and rapider growth rates comparing to the earlier raw materials, it can be a good source for bio-diesel production. Because pond production system is limited in distinguishable four seasons and insufficient land availability in Korea, photo-bioreactor (PBR) is a good alternative way to cultivate microalgae by artificially controlling the internal environments such as light, nutrients, temperature, carbon dioxide, and so on. Despite the availability of these PBRs, only few of them can be practically used for mass production. In this study, computational fluid dynamics (CFD) was used to find an optimum bubble-column PBRs for mass cultivation of the microalgae. Multi-phase models including bubble movement, meshes & time step independent tests were used to design the three dimensional CFD model. The model was validated comparing to the field experiments including particle image velocimetry (PIV) tests. Using the validated CFD model, various types of PBRs were compared quantitatively with consideration of a microalgae growth model adaptable for the CFD model. An evaluation method for mixing efficiency in the PBRs was developed by tracing the movement of each particle in the PBRs connected with the growth model according to the light intensity. The results showed that the mixing efficiency and uniformity in the 20 L of plate type PBRs can be enhanced by 73% and 36% respectively when the baffle was installed in order to guide the fluid flow using bubble injection.

버블 칼럼 광생물반응기의 내부 유동분석을 위한 전산유체역학 시뮬레이션 모델의 이용

유재인,이인복,황현섭,홍세운,서일환,권경석,김용희,Yoo, J.I.,Lee, I.B.,Hwang, H.S.,Hong, S.W.,Seo, I.H.,Bitog, J.P.,Kwon, K.S.,Kim, Y.H. 한국농공학회 2009 한국농공학회논문집 Vol.51 No.5

Photobioreactor (PBR) that houses and cultivates microalgae providing a suitable environment for its growth, such as light, nutrients, CO2, heat, etc. is now getting more popular in the last decade. Among the many types of PBRs, the bubble column type is very attractive because of its simple construction and easy operation. However, despite the availability of these PBRs, only a few of them can be practically used for mass production. Many limitations still holdback their use especially during their scale-up. To enlarge the culture volume and productivity while supplying optimum environmental conditions, various PBR structures and process control are needed to be investigated. In this study, computational fluid dynamics (CFD) was economically used to design a bubble-column type PBR taking the place of field experiments. CFD is a promising technique which can simulate the growth and production of microalgae in the PBR. To study bubble column PBR with CFD, the most important factor is the possibility of realizing bubble. In this study, multi-phase models which are generally used to realize bubbles were compared by theoretical approaches and comparing in a 2D simulation. As a result, the VOF (volume of fluid) model was found to be the most effective model to realize the bubbles shape as well as the flow inside PBR which may be induced by bubble injection. Considering the accuracy and economical efficiency, 0.005 second time step size was chosen for 2.5 mm mesh size. These results will be used as criteria for scale-up in the PBR simulation.

축산 악취의 확산 모델 개발을 위한 현장 실험

홍세운,이인복,황현섭,서일환,권혁진,유재인,권경석,하태환,김용희,Hong, S.W.,Lee, I.B.,Hwang, H.S.,Seo, I.H.,Kwon, H.J.,Bitog, J.P.,Yoo, J.I.,Kwon, K.S.,Ha, T.H.,Kim, Y.H. 한국농공학회 2008 한국농공학회논문집 Vol.50 No.4

Odor is one of the major nuisances in the environment. In most countries, odor annoyance from livestock production is an increasing problem in community. In order to reduce the odor inconvenience and establish a good relation between livestock industries and the surrounding communities, many studies, such as diffusion simulations and field experiments, on the odor dispersion and its reduction have been investigated. These studies need to accompany the aerodynamic approach, as a main mechanism of diffusion phenomenon, and computational fluid dynamics(CFD) can be effectively used to study this kind of research. CFD considers both various wind conditions as well as topographical conditions to study aerodynamic phenomenon. Therefore the ultimate objective of the study was to develop an aerodynamic model to predict qualitatively and quantitatively odor diffusion from livestock. In this study, as the first step of this study, various phenomena and factors of odor diffusion from livestock houses were investigated through field experiments in 2007. Later, those data will be also used to verify the CFD accuracy as well as to develop 3-dimensional CFD model.

CFD 시뮬레이션을 활용한 미세조류 배양용 버블 칼럼 광생물반응기 설계

유재인 ( J. -i. Yoo ),이인복 ( I. -b. Lee ),황현섭 ( H. -s. Hwang ),서일환 ( I. -h. Seo ),홍세운 ( S. -w. Hong ),( J. Bitog ),권경석 ( K. -s. Kwon ),최지선 ( J. -s. Choi ) 한국농공학회 2009 한국농공학회 학술대회초록집 Vol.2009 No.-

Photobioreactors (PBRs) that houses and cultivates microalgae providing a suitable environment for its growth, such as light, nutrients, CO2,heat, etc. is now getting more popular in the last decade. Among the many types of PBRs, the bubble column type is very attractive because of its simple construction and easy operation. However, despite the availability of these PBRs, only a few of them can be practically used for mass production. Many limitations still holdback their use especially during their scale-up. To enlarge their culture volume and productivity by supplying optimum environmental conditions, various PBR structures and processes for controlling are needed to be compared. In this study, computational fluid dynamics (CFD) was used to design a bubble-column type PBR to economically take the place of field experiments. CFD is a promising technique which can simulate the growth and production of microalgae in the PBR. To study bubble column PBR with CFD, the most important factor is the possibility of realizing bubble. In this study, multi-phase models which are generally used were compared by theoretical approaches and 2D preliminary simulations. As a result, the VOF (Volume of Fluid)model was found to be the most effective to realize the bubble shape and flow inside PBR which is made by bubble injection. Considering the accuracy and economical efficiency, 0.005 sec of time step size was chosen for 2.5 mm mesh size. With these initial conditions, 3-D PBR trial simulation and PIV (Particle Image Velocimetry) validation test were conducted. The verified CFD simulation model will be used as criteria for PBR scale-up research.

돈사의 시설 및 환기구조에 따른 돼지 호흡기성 질병 발생 가능성

서일환 ( Seo I. -h. ),이인복 ( Lee I. -b. ),황현섭 ( Hwang H. -s. ),홍세운 ( Hong S. -w. ),( Jessie P. Bitog ),유재인 ( Yoo J. I. ),권경석 ( Kwon K. -s. ),김용희 ( Kim Y. -h. ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

The typical diseases for pigs in Korea are Porcine epidemic diarrhea (PED), Porcine reproductive and respiratory syndrome (PRRS), Post weaning multi-systemic wasting syndrome (PMWS), and Porcine respiratory disease complex (PRDC). The main factor for the occurrence of these diseases specially the respiratory diseases is the environmental condition particularly ventilation inside the pig house. Considering that Korea has 4 distinct season, the environmental condition in the pig house changes every season. The purpose of this study was to find the relationship between the configuration of the structure and ventilation system of pig houses and the occurrence of pig respiratory disease. The effect of internal airflow distribution to internal disease dispersion in pig house was analyzed. Several field experiments were conducted at several pig farms to understand the environmental control in relation to disease occurrence. To overcome the difficulties of conducting field experiments and obtain internal airflow visualization quantitatively and qualitatively, computational fluid dynamic (CFD). The accuracy of the simulations was preliminarily examined and improvements were made in the model based form the seasonally collected farm data.

전산유체역학을 이용한 돈사 건물 간 입자 전파 분석

최지선 ( J. -s. Choi ),이인복 ( I. -b Lee ),서일환 ( I. -h. Seo ),김용희 ( Y-h Kim ) 한국농공학회 2010 한국농공학회 학술대회초록집 Vol.2010 No.-

한국의 양돈산업은 생산성 증대를 위해 대규모화 추세를 보이고 있다. 대형화로 인하여 질병 발생 시 확산 위험이 높아지고 피해규모 역시 커지며 특히 사료나 가축분뇨 등에서 발생하는 먼지에 병원체가 부착되어 전파될 수 있기 때문에 위생조건 관리와 유지의 중요성이 강조된다. 공기 오염물질의 확산은 공기의 유동장에 따라 그 양상이 달라지는데 우리나라는 약 64% 가 산악지대이기 때문에 지형 조건이 공기의 유동장 형성에 중요한 요소로 작용한다. 본 연구에서는 돈사 건물 간 공기 오염물질에 대한 전파에 대하여 공기역학적 분석을 실시하고자 한다. 이를 위하여 현장실험을 통해 돈사 건물 주위와 그 지역의 기상조건을 파악하고, 양돈장 주위의 분진을 포집하여 바이러스의 발생 여부와 입자의 이동을 확인함으로써 질병의 전파 경로의 예측하고자 한다. 현장실험에서 점 측정 및 불안정하고 예측이 어려운 환경 조건 등의 한계를 보완하고자 전산유체역학(CFD) 기술을 이용하여 이를 구현하였다. GIS수치지도에서 필요한 정보를 추출하고 CAD프로그램 등을 이용하여 지형을 3차원으로 구성한다. 구성된 3차원 지형은 Gambit을 이용하여 격자를 생성 한 뒤Fluent를 이용하여 공기의 유동을 구현할 수 있다. 본 연구에서는 국내 양돈장 구조 및 지형 등에 따른 입자확산 모델 연구를 통하여 각 건물 간 영향을 미치는 영향이나 위험도를 산정하여 농장 설계 시 이를 고려할 수 있는 방안을 모색할 수 있도록 한다.