Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly efficient.And the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,...Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly efficient.And the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,distance between fan and coil,fan structure and air inlet type.Under natural air convection or forced,experimental studies were made on the effects of these factors upon the heat dissipation performance of HFC.The results show that:1)After reducing the leakage through coil bypass,the heat dissipation of HFC increases 16.9% under natural convection,and increases 8.3% under forced convection.2)After the distance between fan and coil be raised from 23.2cm to 41.7cm,the heat dissipation of HFC decreases 21.3% under natural convection,but increases12.8% under forced convection.3)After changing the fan structure,the heat dissipation of HFC increases 41.8% under natural convection,and the heat dissipation per motor power increases 96.1% under forced convection.4)The heat dissipations of HFC with round pass,slit and strip type of air inlet are different,whose proportion is about 100%,110%,136% under natural convection,and 100%,105%,116% under forced convection.展开更多
为研究奶牛舍采用扰流风机降温对奶牛泌乳性能和免疫功能的影响,该研究选择结构和饲养管理相同的两栋泌乳牛舍,检测安装风机(风机舍)和不安装风机(对照舍)对不同时期奶牛泌乳性能、淋巴细胞凋亡率、血液理化指标及免疫相关基因mRNA表达...为研究奶牛舍采用扰流风机降温对奶牛泌乳性能和免疫功能的影响,该研究选择结构和饲养管理相同的两栋泌乳牛舍,检测安装风机(风机舍)和不安装风机(对照舍)对不同时期奶牛泌乳性能、淋巴细胞凋亡率、血液理化指标及免疫相关基因mRNA表达的影响,并分析奶牛泌乳性能、免疫性能指标与等温指数(equivalent temperature index for cattle,ETIC)之间的相关性。结果表明:1)安装风机改善了舍内温热环境,整个试验期风机舍的平均ETIC较对照舍降低了3.52℃,有效缓解了奶牛的热应激。2)风机舍的产奶量和4%标准乳在试验中、后期均显著高于对照舍(P<0.05),且风机舍的乳脂率较对照舍也表现出显著性提高(P<0.05)。3)安装风机改善了热应激条件下奶牛的免疫功能。与对照舍相比,风机舍奶牛血液中淋巴细胞数量在试验中、后期显著增加(P<0.05),并降低了淋巴细胞的早期凋亡率(P<0.05),淋巴细胞中促凋亡因子Bax的mRNA表达量及其血清浓度在试验后期均表现出显著性降低(P<0.05),抗凋亡因子Bcl-xl的mRNA表达量(P<0.01)及其血清浓度(P<0.10)在试验中、后期表现出增加趋势。此外,风机舍的血清白细胞介素-12(Interleukin-12,IL-12)和免疫球蛋白G(Immunoglobulin G,IgG)浓度较对照舍也表现出显著性增加(P<0.05)。4)从各项指标之间的相关分析得出,乳蛋白率、淋巴细胞数量与ETIC均呈显著负相关关系(P<0.05),淋巴细胞BAK mRNA表达、血清IL-6浓度与ETIC呈显著正相关关系(P<0.05)。可见,安装扰流风机可改善舍内温热环境,有效缓解夏季奶牛的热应激,提高奶牛生产性能和免疫功能。展开更多
基金Supported by National11th Five-Year Plan Major Scientific and Technological Issues of China(2006BAJ01A04)
文摘Heating-only fan coil(HFC)is one of the suited end users,which is not only compact but also highly efficient.And the major factors affecting the heat dissipation performance of HFC include leakage through coil bypass,distance between fan and coil,fan structure and air inlet type.Under natural air convection or forced,experimental studies were made on the effects of these factors upon the heat dissipation performance of HFC.The results show that:1)After reducing the leakage through coil bypass,the heat dissipation of HFC increases 16.9% under natural convection,and increases 8.3% under forced convection.2)After the distance between fan and coil be raised from 23.2cm to 41.7cm,the heat dissipation of HFC decreases 21.3% under natural convection,but increases12.8% under forced convection.3)After changing the fan structure,the heat dissipation of HFC increases 41.8% under natural convection,and the heat dissipation per motor power increases 96.1% under forced convection.4)The heat dissipations of HFC with round pass,slit and strip type of air inlet are different,whose proportion is about 100%,110%,136% under natural convection,and 100%,105%,116% under forced convection.
文摘为研究奶牛舍采用扰流风机降温对奶牛泌乳性能和免疫功能的影响,该研究选择结构和饲养管理相同的两栋泌乳牛舍,检测安装风机(风机舍)和不安装风机(对照舍)对不同时期奶牛泌乳性能、淋巴细胞凋亡率、血液理化指标及免疫相关基因mRNA表达的影响,并分析奶牛泌乳性能、免疫性能指标与等温指数(equivalent temperature index for cattle,ETIC)之间的相关性。结果表明:1)安装风机改善了舍内温热环境,整个试验期风机舍的平均ETIC较对照舍降低了3.52℃,有效缓解了奶牛的热应激。2)风机舍的产奶量和4%标准乳在试验中、后期均显著高于对照舍(P<0.05),且风机舍的乳脂率较对照舍也表现出显著性提高(P<0.05)。3)安装风机改善了热应激条件下奶牛的免疫功能。与对照舍相比,风机舍奶牛血液中淋巴细胞数量在试验中、后期显著增加(P<0.05),并降低了淋巴细胞的早期凋亡率(P<0.05),淋巴细胞中促凋亡因子Bax的mRNA表达量及其血清浓度在试验后期均表现出显著性降低(P<0.05),抗凋亡因子Bcl-xl的mRNA表达量(P<0.01)及其血清浓度(P<0.10)在试验中、后期表现出增加趋势。此外,风机舍的血清白细胞介素-12(Interleukin-12,IL-12)和免疫球蛋白G(Immunoglobulin G,IgG)浓度较对照舍也表现出显著性增加(P<0.05)。4)从各项指标之间的相关分析得出,乳蛋白率、淋巴细胞数量与ETIC均呈显著负相关关系(P<0.05),淋巴细胞BAK mRNA表达、血清IL-6浓度与ETIC呈显著正相关关系(P<0.05)。可见,安装扰流风机可改善舍内温热环境,有效缓解夏季奶牛的热应激,提高奶牛生产性能和免疫功能。
