Analysis of Temperature Changes in Greenhouses with Recirculated Water Curtain System

Hyung-Kweon Kim; Jong-Gil Jeon; Yee Paek; Hee-Young Pyo; Jae-Woan Jeong; Yong-Cheol Kim

doi:10.12791/KSBEC.2015.24.2.093

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2015 Vol.24, Issue 2 Preview Page

Analysis of Temperature Changes in Greenhouses with Recirculated Water Curtain System 순환식 수막하우스의 수온에 따른 플라스틱 온실 내 온도변화 분석

30 April 2015. pp. 93-99

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Abstract

The purpose of this study was to determine the appropriate temperature for water curtain in greenhouses equipped with recirculated water curtain system. The study analyzed the changes in air temperature in non-heated greenhouses for strawberry cultivation based on outdoor temperature, water curtain temperature and night time. Three greenhouse units were used for this study: The first unit was assigned as a control (no water curtain system), two other greenhouses were equipped with recirculated water curtain system with water curtain temperatures of 10°C and 15°C, respectively. Analysis showed that the indoor temperatures were directly correlated with the outdoor temperature in all experimental greenhouses. Heat insulating effect of 15°C water curtain was increased by 1.3°C compared to that in 10°C water curtain system. The 15°C water curtain treatment showed the highest average temperature and less temperature variation in comparison with control and 10°C water curtain treatment. To maintain indoor temperature at 5°C, water curtain temperature of 10°C was suitable when outdoor minimum and average temperatures were -1.3 and 1.5°C, and water curtain temperature of 15°C was suitable when outdoor minimum and average temperatures were -4.7 and -0.2°C, respectively. The highest temperature in greenhouses according to measurements in different periods of night time was observed after sunset (18:30-20:30), and the lowest temperature before sunrise (05:00-07:00). Water curtain maintained a target indoor temperature by acting as a layer of heat transfer insulator which decreased heat loss from greenhouses. Therefore, water temperature in recirculating water curtain systems should be determined by considering outdoor temperatures, changes in temperature at different periods of night time, and cultivated crop.

Keywords

before sunrise

heat insulating effect

minimum temperature

strawberry

water curtain

순환식 수막시스템의 적정 수온을 결정하는데 필요한 기초자료를 제공하기 위하여 딸기를 토경재배하고 있는 실험온실에서 외부온도, 수막용수의 수온 및 야간시간대 에 따른 처리방식별 온실 내부 환경변화를 비교 분석하 였다. 대조구는 무수막 온실이고, 처리구는 수온이 10°C, 15°C로 각각 설정된 순환식 수막온실로서 모두 무가온 및 추가적인 보온자재의 투입이 없는 상태를 말한다. 수 막이 직접 살수되는 2중 비닐하우스는 폭 5.5m, 길이 55m이고, 분당 살수되는 평균 수막유량은 38.5~44.5L로 나타났다. 3가지 처리조건 모두에서 외부온도와 내부온 도는 양의 선형관련성이 매우 높게 나타났으며 처리구 (10, 15°C)의 외부온도에 대한 상관성은 유사한 수준으 로 분석되었다. 보온효과는 수온 15°C 처리구가 수온 10°C 처리구보다 1.3°C 정도 우수한 것으로 나타났다. 외부온도가 약 -8.1~8.6°C 범위에서 변화할 때, 처리조건 별 최저온도는 무처리구, 수온 10°C 처리구, 수온 15°C 처리구가 외부에 비해 각각 6.4, 11.0, 12.3°C 정도 높게 유지되는 것으로 나타났다. 평균 온도는 무처리구, 수온 10°C 처리구, 수온 15°C 처리구의 순으로 높아지고 온 도변화폭은 오히려 작아지는 경향을 보였다. 외부 최저 온도가 -1.3°C, 평균온도가 1.5°C인 날은 수막시스템의 수온을 10°C로, 외부 최저온도가 -4.7°C, 평균온도가 -0.2°C 인 날은 수온을 15°C로 설정해도 온실의 목표온도(5°C) 유지가 가능한 것으로 나타났다. 처리조건별 야간시간대( 일몰 후, 자정, 일출 전, 일출 후)에 따른 온실 내부와 외부의 온도는 전반적으로 일몰직후가 가장 높고, 이후 서서히 감소하여 일출직전이 가장 낮아지는 경향을 보였 다. 따라서 온실의 목표온도 유지를 위해서는 일출직전 시간대에 특히 집중적인 관리가 필요하며, 순환식 수막 시스템의 수온을 획일적으로 15°C 이상으로 결정하기 보다는 외부온도 변화, 야간시간대, 재배작물에 따라 다 르게 결정하는 것이 타당한 것으로 판단된다.

키워드

딸기

보온효과

수막

일출전

최소온도

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Information

Publisher :The Korean Society for Bio-Environment Control
Publisher(Ko) :(사)한국생물환경조절학회
Journal Title :Protected Horticulture and Plant Factory
Journal Title(Ko) :시설원예ㆍ식물공장
Volume : 24
No :2
Pages :93-99
Received Date : 2015-02-02
Revised Date : 2015-03-02
Accepted Date : 2015-05-11
DOI :https://doi.org/10.12791/KSBEC.2015.24.2.093

Journal of Bio-Environment Control ISSN:1229-4675(Print) 2765-3641(Online) 생물환경조절학회지

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