冬季降低孵化厅进风口温度对孵化效果及节能降耗的影响

试验旨在通过冬季正压孵化厅进风口温度对比研究,确定在不影响孵化指标的前提下,降低环境控制耗能的进风口温度参数。试验将入孵种蛋"京粉1号"C段(41~50周龄)商品代合格种蛋680 400个,设置1个对照组、2个试验组。对照组进风口温度设定为26℃(冬季进风口温度日常生产设定值),试验组1、试验组2进风口温度分别设定为24℃、22℃。结果显示:对照组与两个试验组受精蛋孵化率、受精蛋健母雏率、蛋雏比等孵化指标差异均不显著(P>0.05);对照组每月耗煤量及燃煤费用显著高于试验组1及试验组2(P<0.05)。结果表明,冬季将正压孵化厅进风口温度由26℃调整为22℃时,对孵化指标的影响不大,可显著减少耗煤量及燃煤费用。

不同空调室外机热释放率对其周围热环境的影响

采用CFD数值模拟方法,对凹槽内空调室外机热释放率对其周围热环境的影响进行了分析,得出了随着热释放率的增大,室外机进风温度呈上升趋势,同时对凹槽内室外机安装时提出了参考建议。

热风管道加温下日光温室根区温度场的CFD模拟

为探明热风管道加温系统设计参数对根区温度分布均匀性的影响,以单个基质栽培槽为研究对象,采用计算流体力学(Computational fluid dynamics,CFD)方法构建日光温室热风管道根区加温系统模型,探究不同进风口温度、进风口风速及送风管开孔数量下根区温度分布规律,设计正交试验并对每组试验进行数值模拟,确定各参数对根区温度分布均匀性的影响。结果表明:根区温度实测值与模拟值的平均相对误差为0.89%,均方根误差为0.02,模型可靠;随着进风口温度、风速和开孔数量的增大,根区温度不均匀度和最高温度有较为明显的增加,平均温度和最低温度无显著变化;各参数影响根区温度分布均匀性主次顺序为开孔数量>进风口温度>进风口风速。当进风口温度为20℃,进风口速度为7.5m/s,开孔数量为20时根区温度均匀性最好。

Performance Prediction of a Multi-Stage Wind Tower for Indoor Cooling

A theoretical model is developed to establish an indepth understanding of the performance of a three-stage wind tower with a bypass system for indoor cooling in rural dry and hot climates. Model simulations are presented for a wide range of ambient conditions that include inlet wind speed, inlet temperature and relative humidity. Simulation results provide an insight into the desirable water flow rates and air-to-water loadings for comfort zone tem-peratures and relative humidity levels at the exit of the wind tower. Simulations show wind towers with variable cross-sections provide an increase in the cooling power for the same inlet wind speed, inlet air temperature and relative humidity when compared to wind towers with a constant cross-section. The study shall lead to a better understanding to designing wind towers that are both environmentally friendly and energy efficient.