本文選題：低屋面橫向通風(fēng)牛舍 + 數(shù)值模擬�。� 參考：《沈陽工業(yè)大學(xué)》2016年碩士論文

【摘要】：隨著奶牛養(yǎng)殖業(yè)的發(fā)展,奶牛的散養(yǎng)和傳統(tǒng)牛舍的圈養(yǎng)方式已經(jīng)不能滿足現(xiàn)代畜牧業(yè)的要求,2005年美國建成第一棟低屋面橫向通風(fēng)牛舍。低屋面橫向通風(fēng)牛舍能夠滿足大批量養(yǎng)殖奶牛的要求,但是這種牛舍存在以下三個方面的問題:一是牛舍內(nèi)的空氣流場不均勻;二是在夏季給牛舍通風(fēng)時空氣交換率通常在60s~120s的經(jīng)驗范圍內(nèi)取值,不夠精確;三是在冬季時在寒冷地區(qū)給牛舍通風(fēng)會造成牛舍內(nèi)空氣溫度過低,引發(fā)奶牛凍傷等健康問題。本課題采用FLUENT軟件對牛舍的不同形式建立模型進(jìn)行模擬分析。本課題首先針對不同擋風(fēng)板角度(分別取值30°、60°和90°)建立了三種牛舍模型,并通過FLUENT軟件對這三種模型進(jìn)行了速度場的模擬,通過對模擬結(jié)果的分析比較找出了最優(yōu)的擋風(fēng)板角度;其次,通過FLUENT軟件模擬了夏季牛舍在60s、80s、100s和120s四種空氣交換率情況下的室內(nèi)流場,通過比較牛舍內(nèi)的空氣溫度、氣流速度和CH4濃度的分布情況來找出最佳的空氣交換率;最后,通過FLUENT軟件分別模擬冬季牛舍在啟閉天窗兩種情況下和開啟天窗時采用不同的送風(fēng)溫度的情況,通過比較其模擬結(jié)果,找到冬季時最優(yōu)的通風(fēng)形式。通過對FLUENT軟件的模擬結(jié)果進(jìn)行分析研究,得出牛舍擋風(fēng)板的最佳傾斜角度為30°;在夏季時,牛舍通風(fēng)的最佳空氣交換率為80s;在冬季時,開啟天窗的牛舍比關(guān)閉天窗的牛舍通風(fēng)效果好,節(jié)省加熱量,并且開啟天窗的牛舍內(nèi)溫度分布更均勻,在冬季通風(fēng)室外計算溫度下通過對側(cè)面進(jìn)風(fēng)加熱將側(cè)面送風(fēng)溫度提升到4℃可以維持冬季牛舍內(nèi)溫度高于零度。本課題的研究可以為寒冷地區(qū)低屋面橫向通風(fēng)牛舍的優(yōu)化設(shè)計和通風(fēng)運行調(diào)節(jié)提供參考。
[Abstract]:With the development of the dairy cattle breeding industry, the loose raising of dairy cows and the way of the traditional cattle sheds in captivity can no longer meet the requirements of modern animal husbandry. In 2005, the first low roof ventilated cattle shed was built in the United States. The low roof crosswise ventilated cowshed can meet the requirements of large quantities of dairy cattle, but there are three problems in this kind of cattle house: first, the air flow field in the cattle shed is uneven; The other is that the air exchange rate is usually taken within the experience range of 60s~120s when ventilating the cowshed in summer, and the third is that ventilating the cowshed in the cold area in winter will cause the low air temperature in the cowshed and lead to the health problems such as frostbite and so on. In this paper, FLUENT software is used to simulate and analyze the different models of cowshed. In this paper, three kinds of cowshed models are established for different windshield angles (30 擄~ 60 擄and 90 擄) respectively, and the velocity fields of these models are simulated by FLUENT software. Through the analysis and comparison of the simulation results, the optimum angle of the windshield is found. Secondly, the indoor flow field of the summer cowshed under the conditions of 60 s, 80 s, 100 s and 120 s of air exchange rate is simulated by FLUENT software, and the air temperature in the cattle house is compared. The distribution of air velocity and CH4 concentration is used to find out the best air exchange rate. Finally, FLUENT software is used to simulate the different air supply temperature in winter cowshed under the two conditions of opening and closing the skylight and opening the skylight, respectively. By comparing the simulation results, the optimal ventilation in winter is found. By analyzing the simulation results of FLUENT software, it is concluded that the optimum inclination angle of the windshield is 30 擄, the optimum air exchange rate of the cowshed ventilation is 80 s in summer, and the optimum air exchange rate is 80 s in winter. The cowshed that opens the skylight is better ventilated than the barn with the skylight closed, saves more heat, and the temperature distribution in the barn that opens the skylight is more uniform. The side air supply temperature can be raised to 4 鈩，

本文編號：1898660