전산유체역학 기반 다겹보온커튼 설치 및 개방조건에 따른 온실 내부 공기온도와 기류 분석

초록

Environmental control is essential for stable year-round greenhouse production, and thermal curtains are used to reduce winter heat loss. However, their thermal performance may vary with opening direction and opening ratio. This study used computational fluid dynamics to analyze greenhouse air temperature and airflow distributions under no-curtain and east–west and north–south curtain opening conditions at opening ratios of 50%, 25%, and 12.5%. The mean greenhouse air temperature was 5.93°C without the curtain and 8.22°C under the 50% east–west opening condition, indicating a 2.29°C increase with curtain installation. Under east–west openings, the mean temperatures were 8.22, 8.65, and 7.84°C at opening ratios of 50%, 25%, and 12.5%, respectively, whereas values under north–south openings were 6.02, 9.35, and 9.15°C. At the 50% opening ratio, the east–west condition was 2.20°C warmer because cold air entering through the sidewall gaps traveled a longer distance before reaching the space below the curtain. In contrast, at opening ratios of 25% and 12.5%, the north–south condition was 0.70 and 1.31°C warmer, respectively. Reducing the north– south opening ratio from 50% to 25% restricted the downward movement of cold air through the opening and increased the mean air temperature below the curtain from 6.24 to 9.65°C. However, a further reduction to 12.5% did not produce an additional temperature increase. These results suggest that thermal curtain installation can contribute to greenhouse air-temperature retention and that the effects of opening direction and opening ratio are likely to require joint consideration when determining curtain operating conditions. By spatially resolving how the pathway and extent of cold-air intrusion from above the curtain into the cultivation zone vary with opening direction and opening ratio, this study provides baseline information for assessing the potential exposure of crops to cold air during curtain opening in winter.

키워드