共查询到18条相似文献,搜索用时 78 毫秒
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间接蒸发冷却技术用于纺织空调的可行性分析 总被引:8,自引:2,他引:6
间接蒸发冷却技术通过直接从自然环境中获取冷量对空气进行等湿降温,具有节能、经济、环保的优点.介绍了间接蒸发冷却的主要形式、特点及工作原理,根据纺织生产中空气调节的实际要求,结合理论,探讨了间接蒸发冷却技术在棉纺织厂细纱车间与转杯纺车间空气调节中应用的可行性,提出了具体的实施方案,并指出了应注意的问题. 相似文献
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露点间接-直接蒸发冷却空调特性及换热分析 总被引:1,自引:0,他引:1
从热质交换和流体力学的角度分别对露点间接-直接蒸发冷却空调机组的结构和原理进行了分析.结果表明这种空调机组与传统露点间接蒸发冷却器相比,温降幅度大,可以进一步逼近室外空气的露点温度,是露点间接蒸发冷却技术的一个新发展.同时利用降液膜蒸发理论和界面汽化热阱效应对蒸发冷却传热传质过程的影响进行了分析,指出其对蒸发界面均起到强化传热的作用,进而加强了基于露点板式间接两级蒸发冷却空调机组的温降效果. 相似文献
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真空冷却是一种快速蒸发冷却技术,近年来广泛应用于食品工业,在熟肉制品中的应用也逐渐增多。本文介绍了真空冷却技术的原理、优点,以及影响熟肉制品真空冷却的因素。 相似文献
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为探讨露点间接蒸发冷却技术在纺织厂的应用,在浙江绍兴某纺织厂进行了应用实践,通过测试和计算分析得出:露点间接蒸发冷却段(预冷段)可以降温6~8℃,维持室内相对湿度70%~85%;采用全新风可以改善车间空气质量;使用复合式空调机组比纯机械制冷空调机组节能14%左右. 相似文献
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为探讨露点间接蒸发冷却技术在纺织厂的应用,在浙江绍兴某纺织厂进行了应用实践,通过测试和计算分析得出:露点间接蒸发冷却段(预冷段)可以降温6-8℃,维持室内相对湿度70%~85%;采用全新风可以改善车间空气质量;使用复合式空调机组比纯机械制冷空调机组节能14%左右. 相似文献
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为研究消防员防护服面料的舒适性并考察其是否满足欧美国家相关标准,选取了我国消防员防护服常用的几种面料,进行单层织物热阻和湿阻以及多层织物热阻、湿阻和总热损失的测试与分析,考察空气层对多层织物热阻的影响,并将测试结果与欧美标准的相关要求进行对比。结果表明:在厚度大致相同时,外层面料的密度对热阻和湿阻影响较大;因为隔热层材料是非织造布结构,热阻和湿阻较大;空气层的位置对多层织物的热阻值影响不大,但其厚度对多层织物的热阻影响较大;选取的几种面料组合,湿阻低于30 Pa·m~2/W,总热损失高于205 W/m~2,均满足欧美国家相关标准要求。 相似文献
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Evaluating two different evaporative cooling management systems for dairy cows in a hot, dry climate. 总被引:5,自引:0,他引:5
D P Ryan M P Boland E Kopel D Armstrong L Munyakazi R A Godke R H Ingraham 《Journal of dairy science》1992,75(4):1052-1059
Milk production, rectal temperature, live weight gain, reproductive performance, and weather data were obtained on 150 Holstein cows managed under two cooling systems on a large dairy farm in Saudi Arabia during the summer months. Cows were paired at the onset of the trial according to days postpartum, lactation number, and current milk production. Females were then allocated either to a system that forced air, precooled by evaporative cooling, over the cows or to a system that alternately showered a fine mist onto the surface of the cows and then forced air at ambient temperature over them. The cows receiving evaporative cooling and those with spray and fan cooling were on sand and on slatted concrete floor, respectively, during the periods of cooling. The onset of estrus was observed during the night when the cows preferred the unshaded corral. For the 120-d trial period, 84% (62 of 75) of the cows receiving evaporative cooling and 60% (44 of 75) of the cows receiving spray and fan cooling became pregnant. In the evaporative cooling system, the pregnancy rate per insemination was 35.2% (179 inseminations) versus 23.2% (194 inseminations) for spray and fan cooling. The mean postpartum interval to pregnancy was 117.6 d for the evaporative cooling cows and 146.7 d for spray and fan cooling cows. The evaporative cooling system, with its open shades and sand bedding, enhanced reproductive performance and milk production compared with that of cows cooled with a spray and fan system with slatted flooring in this hot climate. 相似文献
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蒸发冷却+辐射供冷空调系统的设计 总被引:1,自引:0,他引:1
根据蒸发冷却和辐射供冷的热湿处理空调特性,利用焓湿图分配其热湿负荷.计算辐射供冷水侧的供回水温度、流量、供冷能力等.给出了蒸发冷却新风的送风状态点和送风量的求解结果,并给出了冷源设备的选型方法. 相似文献
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目的建立一种蒸发光散射检测器的清洗方法。方法在高温氮气流的作用下,利用高浓度的盐酸溶液去除蒸发光散射检测器蒸发管内壁的奶垢;依次用丙酮、乙腈、甲醇、水溶液清洗之后,高温氮气流的作用下继续烘烤;清洗结束后,对蒸发光散射检测器进行面积归一化。结果乳糖在0~4mg/mL范围内,浓度与峰面积采用幂函数方程绘制标准曲线,相关系数大于0.99,检出限为190 mg/100 g;样品的加标平均回收率为96.45%~103.16%,相对标准偏差为3.88%~5.18%;对清洗前后的蒸发光散射检测器进行10次重复性测试,相对标准偏差为0.66%,清洗后检测信号增大2倍,仪器噪音减少4倍。结论本方法适用于蒸发光散射检测器的彻底清洗,可以减少更换蒸发管的次数。 相似文献
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Smith TR Chapa A Willard S Herndon C Williams RJ Crouch J Riley T Pogue D 《Journal of dairy science》2006,89(10):3915-3923
Heat stress has a dramatic impact on the dairy industry, reducing production and profitability throughout the southeastern United States. In many regions, management techniques can be used to mitigate the effects of heat stress, but available cooling technologies are often overwhelmed by the conditions of chronic heat stress present in southeastern United States. Although combining tunnel ventilation and evaporative cooling (evaporative tunnel cooling) seems to provide superior cooling for dairy cows, there is a dearth of reports on the impact of this technology on milk production. A model evaporative tunnel cooling facility in northern Mississippi was studied using 2 groups of 10 lactating Holstein cows housed in the tunnel barn and 2 groups of 10 matched herdmates housed in an adjacent naturally ventilated free-stall barn. Two 10-wk trials were performed in 2 yr beginning June 25, 2001, and May 26, 2003, in which cows housed outside were cooled by traditional fans and shade alone (2003) or with sprinklers (2001). In both years, the use of evaporative tunnel cooling decreased exposure to conditions of moderate heat stress by 84%. Cows cooled by evaporative tunnel ventilation increased feed intake by 12 and 11% over cows housed outside in 2001 and 2003, respectively. Evaporative tunnel cooling had no effect on milk composition, but increased milk yield over the 10-wk trial by 2.6 ± 0.27 and 2.8 ± 0.19 kg/cow per day in 2001 and 2003, respectively. In addition, somatic cell count was decreased 27 to 49% by evaporative tunnel cooling. Thus, under the range of environmental conditions present, evaporative tunnel cooling reliably reduced exposure to conditions of heat stress and improved milk production of lactating dairy cows during the summer season. 相似文献
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Statistical and ANN analysis of thermal and evaporative resistances of multilayered fabric ensembles
Shabaridharan 《纺织学会志》2013,104(9):950-964
In this paper, thermal and evaporative resistance of multilayered fabrics meant for cold weather conditions have been reported. Polyester hollow fibers of 6 denier and 15 denier were used to produce needle-punched fabrics. Full factorial experimental design was used to produce 30 different needle-punched nonwoven fabrics from two different linear densities of fiber by varying mass per unit area and punch density at three and five different levels, respectively. The needle-punched nonwovens were used as insulative middle layer. Single jersey knitted fabric and polytetrafluoroethylene-coated fabric was used as inner and outer layer, respectively. The multilayered fabric ensembles were evaluated for thermal and evaporative resistance using sweating guarded hot plate (SGHP) system. Regression equations were developed to draw the contour plots and to analyze the effect of different parameters on thermal and evaporative resistance of fabrics. Two independent one-way analysis of variance (ANOVA) were conducted to find the significance of linear density of fiber and effect of inner and outer layers on thermal and evaporative resistance of fabrics. The two-way ANOVA was conducted to analyze the effect of mass per unit area and punch density on thermal properties of fabrics and ‘F’ values were calculated. Mean square values of pure error and lack of fit were studied to analyze the fitness of the developed model for thermal properties of fabrics. An artificial neural network (ANN) model was developed to predict the thermal and evaporative resistance of multilayered fabrics and compared with the experimental values. It has been observed that the ANN model predicts the thermal and evaporative resistance of multilayered fabrics with high degree of accuracy. 相似文献