Simulating the effect of forces pit ventilation on ammonia emission from naturally ventilated cow houses with CFD
Simulating the effect of forces pit ventilation on ammonia emission from naturally ventilated cow houses with CFD
复制标题
CFD模拟强制坑通风对自然通风牛舍氨排放的影响
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
H. V. Dooren
中科院分区：
文献类型：
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作者：
A. Sapounas;J. Campen;M. Smits;H. V. Dooren
大气中的NH3主要来源于农业，可引起严重的环境问题，如富营养化和土壤酸化。奶牛场的排放量占农业NH3总排放量的15%。由于开放式建筑，现有的减排方案有限。矿井空气分离被认为是一种潜在的有效选择。在这项研究中，一个商业奶牛楼与板条地板的模型模拟。该模型求解了12种情况下，不同的风速，方向和空气和粪便温度。对于每种情况，获得三个解决方案，对应于a）强制坑通风系统以250和500 m-3 h-1 cow-1的容量应用的建筑物和B）没有强制坑通风系统的建筑物。结果表明，在250和500 m ~（-3）h ~（-1）牛~（-1）时，采用强制通风系统，通风量分别提高了3.1%和6.2%。在1.0、4.0和8.0 m s-1的风速下，矿坑通风系统对矿坑冬季总氨释放的贡献分别为31- 35%、16-19%和11- 8%。相应地，在夏季，系统的贡献范围为44- 48%，20-21%和12- 9%。虽然强制坑通风系统有明显的好处，但来自坑的氨的主要质量流仍然通过建筑物通风开口排放，特别是在高风速下。
Atmospheric NH3, mainly originates from agricultural sources, can cause serious environmental problems related to eutrophication and soil acidification. Emissions from dairy houses are 15% of total agricultural NH3 emissions. Due to open buildings, existing abatement options are limited. Pit air separation was identified as a potentially efficacious option. In this study a model simulation of a commercial dairy cow building with slatted floor is presented. The model was solved for 12 cases, differing wind speed, direction and both air and manure temperature. For each case three solutions were obtained, which correspond a) to a building where a forced pit ventilation system is applied at capacity of 250 and 500 m-3 h-1 cow-1 and b) to a building without forced pit ventilation system. The results show that due to forced pit ventilation system, at 250 and 500 m-3 h-1 cow-1, the ventilation rate was increased 3.1% and 6.2% respectively. The contribution of the pit ventilation system to the total ammonia released from the pit during winter, ranged from 31-35%, 16-19% and 11-8%, for wind speed of 1.0, 4.0 and 8.0 m s-1 respectively. Correspondingly, during summer, the contribution of the system ranged from 44-48%, 20-21% and 12-9%. Although obvious benefits arise from a forced pit ventilation system, the main mass flow of ammonia from the pit still emitted through the building ventilation openings, especially at high wind speeds.