Development of Semi-basement Type Greenhouse Model for Energy Saving

Kim, Seoung Hee,Joen, Jong Gil,Kwon, Jin Kyeong,Kim, Hyung Kweon Korean Society for Agricultural Machinery 2016 바이오시스템공학 Vol.41 No.4

Purpose: The heat culture areas of greenhouses have been continuously increasing. In the face of international oil price fluctuations, development of energy saving technologies is becoming essential. To save energy, auxiliary heat source and thermal insulation technologies are being developed, but they lack cost-efficiency. The present study was conducted to save energy by developing a conceptually new semi-basement type greenhouse. Methods: A semi-basement type greenhouse, was designed and constructed in the form of a three quarter greenhouse as a basic structure, which is an advantageous structure to inflow sunlight. To evaluate the performance of the developed greenhouse, a similar structured general greenhouse was installed as a control plot, and heating tests were conducted under the same crop growth conditions. Results: Although shadows appeared during the winter in the semi-basement type greenhouse due to the underground drop, the results of crop growth tests indicated that there were no differences in crop growth and development between the semi-basement type greenhouse and the control greenhouse, indicating that the shadows did not affect the crop up to the height of the crop growing point. The amount of fuel used for heating from January to March was almost the same between the two greenhouses for tests. The heating load coefficients of the experimental greenhouses were calculated as $3.1kcal/m^2{\cdot}^{\circ}C{\cdot}h$ for the semi-basement type greenhouse and $2.9kcal/m^2{\cdot}^{\circ}C{\cdot}h$ for the control greenhouse. Since the value is lower than the double layer PE (polyethylene) film greenhouse value of $3.5kcal/m^2{\cdot}^{\circ}C{\cdot}h$ from a previous study, Tthe semi-basement type greenhouse seemed to have energy saving effects. Conclusions: The semi-basement type greenhouse could be operated with the same fuel consumption as general greenhouses, even though its underground portion resulted in a larger volume, indicating positive effects on energy saving and space utilization. It was identified that the heat losses could be reduced by installing a thermal curtain of multi-layered materials for heat insulation inside the greenhouse for the cultivation of horticultural products by installing thermal curtain of multi-layered materials for heat insulation inside the greenhouse, it was identified that the heat losses could be reduced.

Development of Semi-basement Type Greenhouse Model for Energy Saving

김승희,전종길,권진경,김형권 한국농업기계학회 2016 바이오시스템공학 Vol.41 No.4

Purpose: The heat culture areas of greenhouses have been continuously increasing. In the face of international oil pricefluctuations, development of energy saving technologies is becoming essential. To save energy, auxiliary heat source andthermal insulation technologies are being developed, but they lack cost-efficiency. The present study was conducted to saveenergy by developing a conceptually new semi-basement type greenhouse. Methods: A semi-basement type greenhouse,was designed and constructed in the form of a three quarter greenhouse as a basic structure, which is an advantageousstructure to inflow sunlight. To evaluate the performance of the developed greenhouse, a similar structured general greenhousewas installed as a control plot, and heating tests were conducted under the same crop growth conditions. Results: Althoughshadows appeared during the winter in the semi-basement type greenhouse due to the underground drop, the results ofcrop growth tests indicated that there were no differences in crop growth and development between the semi-basementtype greenhouse and the control greenhouse, indicating that the shadows did not affect the crop up to the height of the cropgrowing point. The amount of fuel used for heating from January to March was almost the same between the twogreenhouses for tests. The heating load coefficients of the experimental greenhouses were calculated as 3.1 kcal/m2 ․ °C ․ hfor the semi-basement type greenhouse and 2.9 kcal/m2 ․ °C ․ h for the control greenhouse. Since the value is lower than thedouble layer PE (polyethylene) film greenhouse value of 3.5 kcal/m2 ․ °C ․ h from a previous study, Tthe semi-basement typegreenhouse seemed to have energy saving effects. Conclusions: The semi-basement type greenhouse could be operated withthe same fuel consumption as general greenhouses, even though its underground portion resulted in a larger volume,indicating positive effects on energy saving and space utilization. It was identified that the heat losses could be reduced byinstalling a thermal curtain of multi-layered materials for heat insulation inside the greenhouse for the cultivation ofhorticultural products by installing thermal curtain of multi-layered materials for heat insulation inside the greenhouse, itwas identified that the heat losses could be reduced.

방열관의 배치와 관내 유속이 온수난방 온실의 온도분포에 미치는 영향

신현호,김영식,남상운 (사) 한국생물환경조절학회 2019 생물환경조절학회지 Vol.28 No.4

본 연구는 난방온실의 온도분포 균일화를 위한 기초자료 제공을 목적으로 온수난방 방식의 토마토 재배 온실에서 난방실험을 통하여 난방배관의 표면온도와 실내기온 사이의 상관관계를 분석하고, 난방배관의 열전달특성분석과 난방배관 배치의 개선을 통하여 난방배관 표면온도의 편차를 줄이고 균일도를 향상시키기 위한 방안을도출하였다. 서로 다른 두 온실의 온도분포를 분석하여최대편차와 균일도를 검토한 결과, 온수의 유량이 많고난방배관의 길이가 짧게 배치된 온실의 온도편차가 작고, 균일도는 높은 것으로 나타났다. 또한 순환팬을 가동한경우에 온도편차는 작아지고 균일도가 개선되는 것을 확인할 수 있었다. 난방배관의 표면온도와 실내기온 사이의 상관관계를 분석한 결과, 두 온실 모두에서 유의적인(p<0.01) 정적 상관관계가 있는 것으로 나타났다. 온수난방 온실에서 실내기온의 분포는 난방배관 표면온도의 분포에 영향을 받는다는 것을 확인할 수 있었고, 온도편차가 최소화 되도록 난방배관을 배치함으로써 실내기온 분포의 균일도를 개선할 수 있는 것으로 판단되었다. 난방배관의 열전달 특성을 분석한 결과 배관의 길이가 길어지면 온도편차는 커지고, 관내의 유속이 빨라지면 온도편차는 작아지는 것으로 나타났다. 따라서 지선배관의길이가 짧아지도록 난방배관을 배치하고, 관내의 유속을제어함으로써 온실의 온도분포와 환경의 균일성을 개선할 수 있을 것으로 판단되었다. 국내 온실에서 가장 많이 사용하고 있는 튜브레일(40A) 방식의 온수난방시스템에서 하나의 지선배관에서의 온도편차를 3o C 이내로조절하기 위해서는 관내의 유속이 0.2, 0.4, 0.6, 0.8, 1.0m·s-1일 때 난방배관의 길이는 각각 40, 80, 120, 160, 200m 이내로 제한해야 하는 것으로 분석되었다 In order to provide basic data for uniformization of temperature distribution in heating greenhouses, heating experiments were performed in two greenhouses with a hot water heating system. By analyzing heat transfer characteristics and improving pipes layout, measures to reduce the variation of pipe surface temperature and to improve the uniformity were derived. As a result of analyzing the temperature distributions of two different greenhouses and examining the maximum deviation and uniformity, it was found that the temperature deviation of greenhouses with a large amount of hot water flow and a short heating pipe was small and the uniformity was high. And it was confirmed that the temperature deviation was reduced and the uniformity was improved when the circulating fan was operated. The correlation between the surface temperature of the heating pipe and the indoor air temperature was a positive correlation and statistically significant(p<0.01) in both greenhouses. It was confirmed that the indoor temperature distribution in a hot water heating greenhouse was influenced by the surface temperature distribution of heating pipe, and the uniformity of indoor temperature distribution could be improved by arranging the heating pipe to minimize the temperature deviation. Analysis of the heat transfer characteristics of heating pipe showed that the temperature deviation increased as the pipe length became longer and the temperature deviation became smaller as the flow rate in pipe increased. Therefore, it was considered that the temperature distribution and the uniformity of environment in a greenhouse could be improved by arranging the heating pipe to shorten the length and controlling the flow velocity in pipe. In order to control the temperature deviation of one branch pipe within 3oC in the tube rail type hot water heating system most used in domestic greenhouses, when the flow velocity in the pipe is 0.2, 0.4, 0.6, 0.8, 1.0m·s-1, the length of a heating pipe should be limited to 40, 80, 120, 160, 200m, respectively. Additional

지중가온이 온실의 난방부하에 미치는 영향

남상운 ( Nam Sang Woon ) 한국농공학회 2006 한국농공학회논문집 Vol.48 No.5

In order to examine the heat transfer characteristic of a soil warming system and effects of soil warming on the greenhouse heating load, control experiments were performed in two greenhouses covered with double polyethylene film. One treated the soil warming with an electric heat wire and the other treated a control. Inside and outside air temperature, soil temperature and heat flux, and heating energy consumption were measured under the set point of heating temperature of 5, 10, 15, and 20℃, respectively. Soil temperatures in a soil warming treatment were observed 4.1 to 4.9℃ higher than a control. Heating energy consumptions decreased by 14.6 to 30.8% in a soil warming treatment. As the set point of heating temperature became lower, the rate of decrease in the heating energy consumptions increased. The percentage of soil heat flux in total heating load was -49.4 to 24.4% and as the set point of heating temperature became higher, the percentage increased. When the set point of heating temperature was low in a soil warming treatment, the soil heat flux load was minus value and it had an effect on reducing the heating load. Soil heat flux loads showed in proportion to the air temperature difference between the inside and outside of greenhouse but they showed big difference according to the soil warming treatment. So new model for estimation of the soil heat flux load should be introduced. Convective heat transfer coefficients were in proportion to the 1/3 power of temperature difference between the soil surface and the inside air. They were 3.41 to 12.42 W/㎡℃ in their temperature difference of 0 to 10℃. Radiative heat loss from soil surface in greenhouse was about 66 to 130% of total heating load. To cut the radiation loss by the use of thermal curtains must be able to contribute for the energy saving in greenhouse.

Development of Semi-basement Type Greenhouse Model for Energy Saving

( Seoung Hee Kim ),( Jong Gil Joen ),( Jin Kyeong Kwon ),( Hyung Kweon Kim ) 한국농업기계학회 2016 바이오시스템공학 Vol.41 No.4

Purpose: The heat culture areas of greenhouses have been continuously increasing. In the face of international oil price fluctuations, development of energy saving technologies is becoming essential. To save energy, auxiliary heat source and thermal insulation technologies are being developed, but they lack cost-efficiency. The present study was conducted to save energy by developing a conceptually new semi-basement type greenhouse. Methods: A semi-basement type greenhouse, was designed and constructed in the form of a three quarter greenhouse as a basic structure, which is an advantageous structure to inflow sunlight. To evaluate the performance of the developed greenhouse, a similar structured general greenhouse was installed as a control plot, and heating tests were conducted under the same crop growth conditions. Results: Although shadows appeared during the winter in the semi-basement type greenhouse due to the underground drop, the results of crop growth tests indicated that there were no differences in crop growth and development between the semi-basement type greenhouse and the control greenhouse, indicating that the shadows did not affect the crop up to the height of the crop growing point. The amount of fuel used for heating from January to March was almost the same between the two greenhouses for tests. The heating load coefficients of the experimental greenhouses were calculated as 3.1 kcal/m² · ℃ · h for the semi-basement type greenhouse and 2.9 kcal/m² · ℃ · h for the control greenhouse. Since the value is lower than the double layer PE (polyethylene) film greenhouse value of 3.5 kcal/m² · ℃ · h from a previous study, Tthe semi-basement type greenhouse seemed to have energy saving effects. Conclusions: The semi-basement type greenhouse could be operated with the same fuel consumption as general greenhouses, even though its underground portion resulted in a larger volume, indicating positive effects on energy saving and space utilization. It was identified that the heat losses could be reduced by installing a thermal curtain of multi-layered materials for heat insulation inside the greenhouse for the cultivation of horticultural products by installing thermal curtain of multi-layered materials for heat insulation inside the greenhouse, it was identified that the heat losses could be reduced.

나노탄소섬유 적외선등 난방이 절화장미의 생육과 수명 및 난방비에 미치는 영향

임미영(Lim Mi Young),고충호(Chung Ho Ko),손문숙(Moon Sook Son),이상복(Sang Bok Lee),김길주(Gil Ju Kim),김병수(Byung Soo Kim),김영복(Young Bok Kim),정병룡(Byoung Ryong Jeong) (사)한국생물환경조절학회 2009 생물환경조절학회지 Vol.18 No.1

장미 생산농가의 대부분은 겨울철 난방비가 생산비의 가장 큰 몫을 차지한다. 요즘과 같은 고유가 시대에 농가의 부담을 줄이기 위하여 난방비 절감율이 높은 난방시스템에 대한 연구를 수행하였다. 복사열을 이용한 적외선등 난방의 경우 식물체와 같은 물체를 먼저 가열하여 주변의 기온이 올리는 방식으로 빠르게 온도를 높일 수 있고 경유를 이용한 난방방식에 비해 비용이 절감되는 장점이 있다. 농가에 설치된 나노탄소 섬유 적외선등 난방시스템의 현지조사를 실시하여 난방효과 및 난방비 절감율을 분석하고, 나노탄소섬유 적외선등 난방시스템과 전기히터 난방시스템에서 생산된 ‘오렌지 플레쉬’ 장미의 생육과 절화수명을 조사하였다. 나노탄소섬유 적외선등의 경우 온실 내부 공기 설정온도가 20℃인 경우 식물체 온도는 1~2℃ 정도 더 높게 나타났을 뿐만 아니라 베드와 근권부 온도는 17~19℃ 정도로 유지하는 등 우수한 난방의 효과를 알 수 있었고, 전기히터 난방시스템과 온수보일러 난방 시스템의 추정 난방비를 비교한 결과 난방비 절감 효과가 아주 높게 나타났다. 장미의 생육을 조사한 결과 전기히터 난방시템에서 생육한 장미와 차이가 없었으며 화색이나 엽색의 발현이 더 좋았다. 절회수명에서는 나노탄소섬유 적외선등에서 생육한 장미가 생체중과 수분 흡수량이 높아 다소 더 길어진 절회수명을 뒷받침해 주었다. The greatest and major cost for cut rose production during winter seasons in Korea is cost of heating the greenhouse. A study was conducted on a cost-efficient heating system to reduce expenses of cut rose growers in times of high energy prices. An infrared heating system utilizing radiant energy has an obvious advantage over other heating methods in that the energy is first used to raise temperatures of plants and other objects and subsequently that of the atmosphere, resulting in faster reaching to desired plant temperatures at a reduced heating cost. In this study the heating effect and heating cost saving of a nano-carbon fiber infrared heating system (NCFIHS) installed in cut rose greenhouses in Gimhae, Gyeongnam Province were analyzed comparatively. In addition growth, quality, and vase life of 'Orange Fresh' roses grown in greenhouses heated by NCFIHS against those grown in greenhouses heated by so called an electrical heating system. In greenhouses with a NCFIHS with a set point ail" temperature of 20℃, plant temperature was maintained at 1~2℃ higher than the air temperature, and temperatures of growing bed surface and root zone were maintained at 17~19℃ throughout cold winter nights. The cost for heating in NCFIHS was about 25 and 51 % of that of an electrical heating system and a hot water heating system heated by petroleum, respectively. Growth of roses harvested in greenhouses with a NCFIHS was similar to those grown in greenhouses with an electrical heating system. However, cut roses with more intense petal and leaf colors and a longer vase life (fresh weight and amount of water uptake) were harvested in greenhouses with a NCFIHS as compared to those harvested in greenhouses with an electrical heating system.

강변여과수를 이용한 온실난방기술 개발

문종필,이성현,권진경,강연구,유영선,이수장,Moon, Jong-Pil,Lee, Sung-Hyoun,Kwon, Jin-Kyung,Kang, Youn-Ku,Ryou, Young-Sun,Lee, Su-Jang 한국농공학회 2011 한국농공학회논문집 Vol.53 No.6

In order to heat greenhouse nearby river channel, riverbank filtration water source heat pump was developed for getting plenty of heat flux from geothermal energy. Recharging well, thermal storage tank with separating insulation plate and filtering tank for eliminating iron, manganese were mainly developed for making the coefficient of performance (COP) of heat pump higher. Heating system using riverbank filtration water source heat pump was installed at a paprika greenhouse in the Jinju region where a single fold of vinyl cover and 2 layers of horizontal thermal curtain were installed as a part of temperature keeping and heat insulation with a greenhouse area of 3,185 $m^2$. 320,000 kcal/h was supplied for performing a site application tests. A greenhouse heating test was performed from Feb. 1, 2011 to Apr. 30, 2011. As the result of that, COPh of the heat pump was measured in the range of 4.0~4.5, while COPS of the system was represented as 2.9~3.3. COP measured of the heat pump was very good and well responded to indoor heating temperature of the environment control system of a greenhouse.

지역별 온실내의 잉여 태양에너지 산정

윤용철,임재운,김현태,김영주,서원명 경상대학교 농업생명과학연구원 2011 농업생명과학연구 Vol.45 No.4

본 연구에서는 주간동안 온실 내에서 발생되는 잉여 태양에너지를 분석하고, 또한 잉여 태양에너지의 적정 축열 시스템 설계에 필요한 기초자료를 제공할 목적으로 수행하였다. 분석에 이용된 기상자료는 표준기상년 데이터로서 이용하여 국내 주요 지역을 대상으로 온실 형태별로 잉여 태양에너지를 분석하였을 뿐만 아니라 소요 난방에너지 등도 분석 및 검토하였다. 이상의 결과를 요약하면 다음과 같다. 9개 지역을 대상으로 지역별 잉여 태양에너지를 대해 분석한 결과, 난방에너지 대비 잉여 태양에너지 비율은 온실 형태별로 각각 약 212.0~228.0%로서 제주가 가장 높게 나타났다. 그 다음으로 부산, 광주, 진주, 대구, 대전, 전주, 수원, 및 대관령 순으로 나타났다. 그리고 온실 형태에 관계없이 몇 몇 지역을 제외하면 잉여 태양에너지만으로 소요 난방에너지를 거의 대체할 수 있을 것으로 판단되었다. This research was conducted to provide basic data of surplus heat for designing solar heat-storage systems. The surplus heat is defined as the heat exhausted by forced ventilations from the greenhouses to control the greenhouse temperature within setting limits. Various simulations were performed to compare the differences of thermal behaviors among greenhouse types as well as among several domestic areas by using pseudo-TMY (Typical Meteorological Year) data manipulated based both on the weather data supplied from Korean Meteorological Administration and the TMY data supplied from The Korean Solar Energy Society. Additional analyses were carried out to examine the required heating energy together with some others such as the energy balances in greenhouses to be considered. The results of those researches are summarized as follows. Regional surplus solar heats for the nine regions with 4-type were analyzed. The results showed that the ratio of surplus solar energy compared to heating energy was the highest in Jeju (about 212.0~228.0%) for each greenhouse type. And followed by Busan, Kwangju, Jinju, Daegu, Daejeon, Jeonju, Suwon and Daekwanryung. And irrespective of greenhouse types, surplus solar energy alone could cover up nearly all of the required supplemental heating energy except for a few areas.

Thermal-Load Analysis of Semi-Basement-Type Single-Span Greenhouse

김승희,권진경,강연구,문종필,김형권,전종길 한국농업기계학회 2019 바이오시스템공학 Vol.44 No.3

Purpose The proposed study was performed to investigate thermal-load characteristics required for heating of a semi-basementtype greenhouse, which is different from conventional greenhouses. Methods To determine whether the thermal load of a semi-basement-type greenhouse is different from that of conventional greenhouses, values of the heat-transfer coefficient, heat-transmission coefficient of greenhouse cover, soil heat flux, and infiltration heat-transfer coefficient that were calculated and compared against data obtained from extant studies. Results The heat-transfer coefficient was estimated to be 2.6 W/m2°C, whereas values of the heat-transmission coefficient for greenhouse cover, soil heat flux, and infiltration heat-transfer coefficient (obtained using the heat-balance relation) equaled 2.1 W/m2°C, − 10.3 W/m2, and 0.1 W/m2°C, respectively. Values of the greenhouse cover and infiltration heat-transfer coefficients were observed to lie within the feasible range of data reported in extant studies. That said, values of the greenhouse heattransfer coefficient and soil heat flux, respectively, measured slightly higher and lower compared to corresponding values observed in extant studies. Conclusions Although semi-basement-type greenhouses occupy an underground space, their observed thermal performance is not much different from that of greenhouses installed level with the earth’s surface.

Agri-environmental System Engineering and Energy : Development of On-site Heat Loss Audit and Energy Consulting System for Greenhouse

( Jin Kyung Kwon ),( Geum Choon Kang ),( Seong Hyun Lee ),( Je Hoon Sung ),( Nam Kyu Yun ),( Jong Pil Moon ),( Su Jang Lee ) 한국농업기계학회 2013 바이오시스템공학 Vol.38 No.4

Purpose: Greenhouses for a protected horticulture covered with a plastic or glass are easy to have weakness in a heat loss by deterioration, damage, poor construction, and so on. To grasp the vulnerable points of heat loss of the greenhouses is important for heating energy saving. In this study, an on-site heat loss audit and energy consulting system were developed for an efficient energy usage of a greenhouse. Method: Developed system was mounted with infrared thermal and visual cameras to grasp the heat loss from the greenhouse quickly and exactly, and a trial calculation program of heating load of greenhouse to provide farmers with the information of heating energy usage. Results: Developed system could print out the reports about the locations and causes of the heat losses and improvement methods made up by an operator. The mounted trial calculation program could print out the information of the period heating load and fuel cost according to the conditions of greenhouse and cultivation. The program also mounted the databases of the information on the 13 horticultural energy saving technologies developed by the Korea Rural Development Administration and simple economic analysis sub-program to predict the payback period of the technologies. Conclusion: The developed system was expected to be used as the basic equipment for an instructors of district Agricultural Technology and Extension Centers to conduct the energy consulting service for the farmers within the jurisdiction.