Improvement of the ventilation system of a naturally ventilated broiler house in the cold season using computational simulations
Improvement of the ventilation system of a naturally ventilated broiler house in the cold season using computational simulations
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DOI：
10.1016/j.biosystemseng.2009.05.007
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发表时间：
2009-09-01
影响因子：
5.1
通讯作者：
Han, J. -W.
中科院分区：
文献类型：
--
作者：
Seo, I. -H.;Lee, I. -B.;Han, J. -W.
有限的测量点和不可预测的气流，以及无法控制的天气条件，使得进行现场实验来研究肉鸡舍的通风非常困难。使用计算流体动力学（CFD）的模拟通常用于克服上述限制。在这项研究中，气流，内部空气温度分布和通风效率的传统通风系统和几个修改后的通风系统进行了定量和定性分析使用以前开发的CFD模型。进行这些分析是为了改善传统自然通风肉鸡舍的饲养条件。示踪气体衰减方法适用于CFD主求解器，利用用户定义的函数来计算通风效率，并使用建筑能量模拟（BES）方法来计算热负荷。为了复制在现场实验中遇到的通风问题，各种通风系统进行了研究，在寒冷的季节与四种不同类型的通风口：烟囱，侧通风口，屋顶下的管道和檐侧通风口。根据计算流体力学结果，最佳结果是通过在烟囱入口下方使用扩散器的模型获得的，该扩散器将进入的冷空气与在肉鸡舍上部积聚的暖空气混合。靠近内侧壁安装的附加帘有效地将废气引导到排气口，并将进入的新鲜空气引入肉鸡区。窗帘还加强了侧墙的隔热效果。由于其在肉鸡区的高通风效率，与传统的肉鸡舍相比，热均匀性提高了32%，热适应性提高了14%。BES结果表明，该模型可以节省47%的能量输入在肉鸡区相比，传统的通风系统。一个额外的现场实验表明，一个升级的肉鸡舍适应该模型节省了30%的能源成本。皇冠版权（C）2009年由爱思唯尔有限公司代表IAgrE出版。All rights reserved.
Limited measurement points and unpredictable airflows, as well as uncontrollable weather conditions, make conducting field experiments to study ventilation in broiler houses very difficult. Simulations using computational fluid dynamics (CFD) are often used to overcome the above mentioned limitation. In this study, airflow, internal air temperature distribution and ventilation efficiency of a conventional ventilation system and several modified ventilation systems were analysed both quantitatively and qualitatively using a previously developed CFD model. These analyses were conducted in order to enhance the rearing condition of the conventional, natural ventilated broiler houses. A tracer gas decay method was adapted to the CFD main solver utilising a user-defined function to calculate the ventilation efficiency and building energy simulation (BES) method was used to compute the heating load. In order to replicate the ventilation problems encountered during the field experiment, the various ventilation systems were studied in the cold season with four different types of vent openings: a chimney, a side vent, a pipe under the roof and a side-up vent at the eaves. From the CFD results, the optimum results were obtained with a model that used a diffuser beneath the chimney inlet which mixed the incoming cold air with the warm air that had accumulated in the upper portion of the broiler house. An additional curtain installed close to the internal side wall effectively guided exhaust gas to the outlet vents and introduced the incoming fresh air to the broiler zone. The curtain also enhanced the thermal insulation at the side wall. Because of its high ventilation efficiency in the broiler zone, compared with a conventional broiler house there was a 32% increase in the thermal uniformity and a 14% increase in the thermal suitability. The BES results indicated that the model could save 47% of the energy input at the broiler zone compared to the conventional ventilation system. An additional field experiment demonstrated that an upgraded broiler house adapted to the model saved 30% of energy costs. Crown Copyright (C) 2009 Published by Elsevier Ltd on behalf of IAgrE. All rights reserved.