大氣風向與排氣方向相反條件下密閉水簾式雞舍尾端排氣設計對於汙染物再進入之影響:以雲林某雞舍為例

Abstract

隨著氣候變遷與禽流感的頻繁發生，現行畜牧政策推動將風險較高之傳統開放式雞舍改為水簾密閉式設計，雖有助於提升雞舍內部生物安全，卻可能因外部風場干擾導致污染物回流至雞舍內部，威脅工作者之職業健康與禽隻健康。因此本研究旨在探討密閉式水簾雞舍在環境風向與雞舍排氣方向相反時，污染粒子於雞舍外之流場結構與粒子分布行為，並分析不同排氣改善設計與水簾開啟條件對於粒子再進入（re-entry）風險與職業健康風險之影響。本研究採用計算流體力學模擬技術，建構三種不同排氣設計（水平排氣、水平排氣有擋風牆、向上排氣）與兩種進氣水簾配置（只開啟正面水簾與三面水簾全開），共六組模擬模型。模擬中設定三種粒徑（2.5 μm、10 μm 及 100 μm）進行粒子研究，並觀察粒子之分布熱區評估再進入風險及雞舍外暴露風險。研究結果顯示，粒子受流場影響容易集中沉積於排氣口、水簾表面、建築兩側地面與屋頂等沉積熱區，增加牧場區內之粒子暴露風險，而在綜合評估下最理想之設計改善為水平排氣加擋風牆設計，不僅較符合現行法規，也較達到實際使用情況與污染控制的實務需求間之平衡。此外，針對粒子沉積熱區，應實施定期清消作業，並配合個人防護以降低粒子濃度與健康風險。綜合研究結果顯示，排氣設計、水簾開啟條件與環境風場三者交互影響粒子行為與再進入風險。未來禽舍設計應整合考量污染控制、設施維護與職業健康，以實現更安全、永續之畜禽養殖場域管理策略。

With the rising frequency of climate change and avian influenza outbreaks, current livestock policies are promoting the transition from traditional poultry houses to enclosed water-pad poultry houses While improving internal biosecurity, these designs may also increase the risk of pollutant re-entry due to interference from atmospheric wind, posing health risks to both workers and poultry. This study uses Computational Fluid Dynamics simulations to examine particle behavior around enclosed water-pad poultry houses when external wind opposes exhaust flow. Six models were constructed by combining three exhaust configurations (horizontal, horizontal with windbreak wall, and upward) with two water pad setups (front-only and fully open). Particles of 2.5 μm, 10 μm, and 100 μm were analyzed for adhesion hotspots and re-entry risk. Results showed that airflow interference leads to particle accumulation at key locations such as the exhaust outlet, water pad surfaces, building sides, and rooftops, increasing external exposure risks. Among all designs, the horizontal exhaust with windbreak wall offered the most balanced solution. Regular disinfection and use of personal protective measures to reduce health hazards, alongside additional dust control devices. In conclusion, exhaust configuration, inlet conditions, and wind direction collectively influence particle dispersion and re-entry risks. Future poultry house design should integrate pollution control, maintenance, and occupational health strategies to achieve safer and more sustainable livestock operations.