卷帘开度对奶牛舍温湿环境影响研究
发布时间:2018-04-17 19:30
本文选题:卷帘开度 + 空气流场 ; 参考:《黑龙江八一农垦大学》2015年硕士论文
【摘要】:为了确定高寒地区冬季带有卷帘的自然通风密闭式奶牛舍内部温湿度场的分布情况,研究了不同卷帘开度下,牛舍内温湿度场的分布情况。进而对现有牛舍不同舍外温度下的的卷帘开度提出合理化建议及理论依据。在对黑龙江省齐齐哈尔市克东县飞鹤牧业克东原生态牧场牛舍气流进行现场实测的基础上,采用计算流体动力学CFD(Computational FluidDynamic)方法,根据现场实测值和相关参数查询,对高寒地区冬季奶牛舍某一时刻的温湿度场进行数值模拟,模拟结果表明,使用CFD对牛舍内温、湿度场模拟是可行的。舍外空气进入牛舍后,在与牛体周围空气进行热质交换后,温度升高近6℃,相对湿度增大至91%以上。在热压的作用下,由出口排出,在带走水蒸气的同时带走了大量的热,,是导致牛舍内温度偏低的主要原因。现有的牛生活区域平均温度在-15℃,相对湿度在91%以上,属于低温高湿的环境。对奶牛的产奶性能有一定的影响,应通过增大送风量或增设其它采暖设施改善现有环境。通过测试和查阅资料,确定了影响牛舍内空气流场的因素。通过140不同工况下的模拟,绘制了相对湿度随着温度变化所对应的最佳卷帘开度的变化曲线图。本文的创新之处:以往模拟时边界条件参数选取的是设计值,但是受材料和施工等各种因素的影响,这些参数的理论值和建成后的实际值相差很大。本课题中所需要的设计参数均采用现场实测值,使结果更加精确。
[Abstract]:In order to determine the distribution of temperature and humidity field in the closed dairy cattle shed with natural ventilation in winter in high and cold regions, the distribution of temperature and humidity field in the cowshed was studied under different roll opening degrees.Furthermore, the rational suggestions and theoretical basis are put forward for the rolling curtain opening of the existing cowshed under different temperature outside the shed.Based on the field measurement of the airflow of Kedong Eco-pasture in Kedong County, Qiqihar City, Heilongjiang Province, the computational fluid dynamics (CFD(Computational) method was used to inquire the field measured values and related parameters.The temperature and humidity field of dairy cattle in winter in alpine area was simulated. The simulation results showed that it was feasible to use CFD to simulate the internal temperature and humidity field of dairy cattle.After entering the cowshed, the temperature increased by 6 鈩
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