循环水冷却塔的设计

循环水冷却塔是在塔体内热水从上向下喷散成水滴或水膜状,而空气由下而上或水平方向在塔体内流动与水进行热交换,而降低水温的构筑物。随着我国工业生产的迅速发展,冷却水用量愈来愈多,对冷却塔的淋水装置、布水系统、风机和塔体等各组成部分以及塔形之研究都提出     

喷雾通风冷却塔在味精行业的应用

味精行业的能源消耗主要是水、电、汽三块。随着经济的不断发展和节约水资源的要求，循环冷却塔在行业内的应用是普遍和必不可少的一种装置。以前绝大部分企业都采用填料和电力风机组合的冷却塔，用于发酵罐冷却水和浓缩罐抽汽冷凝冷却水的循环使用。其缺点是：一、填料易堵塞，同时要老化；二、电机、减速器易损坏；三、电机、减速器的运转噪音较大。特别是使用江河水或水质较差的水源，使用效能就很不理想。     

选用玻璃钢冷却塔应复核冷却水量

玻璃钢冷却塔已在盐化工生产得到广泛应用,选用这种冷却塔应根据本地区的气象参数以及冷却任务通过热力计算复核水量,切不可照搬。本文现以成都市金牛玻璃钢制品厂生产的玻璃钢冷却塔 LYB—100型为例加以说明。LYB—100型冷却塔配备 LTF12型风机,该风机     

酒精厂冷却水系统制冷降温设计与节水效果

在酒精的生产过程中，通常采用以开放式冷却塔为降温设备的循环冷却水系统，但其降温效果与气候条件密切相关，高温高湿天气时只能通过大量补充新水来保证冷却水的温度，从而造成水资源的浪费。针对该问题，某酒精厂的冷却水系统在原有冷却塔后增加大型离心式制冷机组，实现冷却水温度的有效降低和控制，在改善工艺条件、节约用水和节约运行费用等方面收到了明显的效果．证明制冷降温技术在工业冷却水领域应用的可行性、合理性和必要性。     

清洁冷却塔真空系统在油脂精炼过程中的应用

介绍了清洁冷却塔真空系统的工艺和设备配置,通过采用碱式闭路真空系统与干式冷凝真空系统实现清洁的循环冷却水系统。与常规真空系统相比,清洁冷却塔真空系统减少了污水的排放,降低了蒸汽耗量,循环冷却水系统的清洗频率大幅降低,没有空气污染。     

如何用好B3-24/5汽轮发电机的冷却水

循环用水或一水多次利用，是节约生产用水的有效途径。B3－24／53·000机组的冷却用水，可分为三种：即发电机的空气冷却水（空冷）、汽轮机轴承润滑油的冷却水（油冷）和汽封表面冷凝器（谷称汽封加热器）的冷却水。这三部份冷却水，在水源充足的糖厂，回真空冷凝塔底下的混合水箱中（两致使用）；在使用地下水的糖厂，将这些水一同经单独的凉水塔冷却后，循环使用。凉水塔型式有两种：东北地区的糖厂因气候寒冷，采用自然通风的冷却塔，其规格和型式与冷凝水自然通风冷却塔完全一样；在关内地区的糖厂，采用玻璃钢冷却塔（例如宁夏青铜峡…     

循环水设备节能技术改造

节能减排是我国一项基本国策.节约能源、降低消耗是企业生存发展的必由之路.安徽德邦化工有限公司循环水装置有二次循环水及三次循环水装置,冷却循环水系统采用开式机械循环,在标准工况下,来自冷水池的低温冷却水由该系统的冷却循环水泵送至生产装置各个区经换热器换热,换热后的高温冷却水由系统压至冷却塔散热冷却,经冷却塔散热冷却后的低温冷却水回落至冷水池,如此循环往复,水损耗由补水系统补给.通过专业的节能服务公司对循环水系统进行检测、分析、研究,挖掘系统装置设备节能技改潜力,分别对三次水泵进行节能技术改造及二次水冷却塔水轮机改造.     

基于MIDAS的大体积混凝土水管冷却仿真分析

随着近年来大型工程的增多，大体积混凝土水化热的温度控制问题变得越来越重要。在桥梁的设计、施工中对大体积混凝土水化热温度场进行研究，对其进行有限元模拟和温度控制是很必要的。文章以石武客运专线跨南水北调总干渠特大桥为例，讨论了冷却水管对大体积混凝土浇注后的降温作用和冷却水管的合理布置。     

基于末端定温差控制的空调系统节能性研究

文章介绍了一种基于定温差控制的末端风机盘管风水联动调节的装置,论述了该装置的应用场景、理论可行性以及定温差控制机理。结合实际项目,通过能耗模拟的方法对建筑负荷进行模拟,得到了全年的负荷分布特性,负荷率在50%-80%的运行时间仅占全年的30%。对传统的末端控制方案(三速风机+二通阀开关温控)与定温差控制方案进行了节能性对比分析。通过末端定温差控制与水系统变流量控制,可使主机节能6.44%,冷冻水泵能耗节能30.60%,冷却水泵节能31.11%,冷却塔节能24.92%,末端节能62.63%,可使中央空调系统节能率达到23.30%。     

卷烟厂生产车间冷却塔冬季供冷节能技术研究

为降低卷烟厂工艺性中央空调制冷系统的运行能耗,以杭州制造部为例,通过分析生产车间冬季供冷需求和杭州室外气象条件,在现有冷冻站供冷系统中增加两套板式换热器及对应的旁通回路,冬季用冷却塔为产热量较大的生产车间免费供冷。分析计算冷却塔在冬季供冷运行模式下的热工性能可知,单台板式换热器的换热能力若达到一台冷水机组的制冷能力水平,应开启2台冷却塔和2台冷却水循环泵同时运行。比较冬季冷却塔供冷与冷水机组变水温两种运行模式可知,冷却塔供冷运行模式的节能效果可提高60%以上,每年可节约用电2.59×106kWh,节省费用约207万元。     

白酒酿造水资源综合利用研究

白酒酿造行业是耗水大户,且污水排放量大。因此如何降低白酒酿造的耗水量,实现水资源的综合利用是白酒清洁生产的关键。该文从传统水资源利用系统、凉水塔水资源利用系统、大型制冷机组水资源利用系统三方面总结了白酒酿造水资源利用发展概况,分析比较了三种系统的优缺点,提出一种新型水资源综合利用解决方案：首先,采用软水作为冷酒水,冷酒后的高温软水一部分降温后循环利用,另一部分用于锅炉产蒸汽;其次,冷酒器采用分段进水设计,一段通入低温软水,二段通入循环水;最后,利用中央控制系统对软水系统、蒸馏系统、冷却系统、热水系统进行功能化控制。该文对水资源综合利用系统的研发,为白酒酿造行业的节能减排提供了参考方案。     

Evaluating two different evaporative cooling management systems for dairy cows in a hot, dry climate.

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.     

Studies on aeration with refrigerated air—III. Chilling of wheat with a modified chilling unit

Two trials on the cooling of grain with refrigerated air are described. The chilling unit had the fan positioned after the evaporator to lower relative humidity of the cooled air entering the grain. A bin containing 699 metric tonnes of wheat was cooled in summer from 30–37°C to 18–19°C in 160 hr at an energy consumption of 4·6 kW/hr/tonne. The second bin containing 863 tonnes of wheat was cooled in winter from temperatures of up to 42°C to 15–21·5°C in 236 hr at an energy consumption of 4·7 kW/hr/tonne. It was shown that grain was not moistened as a result of cooling. The importance of controlling both air temperature and humidity in the cooling system are discussed and this method is compared with aeration using ambient air.     

Effect of early post-mortem cooling on temperature, pH fall and meat quality in pigs

The aim of this study was to investigate how early cooling of carcasses after slaughter by showering with cold water affected the rate of the pH fall post mortem, protein denaturation and drip loss. Eighty pigs were selected in pairs at debleeding according to sex and farm of origin. All pigs were halothane genotyped and glycolytic potential in LD analysed. One of each pair was cooled 30 min post mortem by showering with 10-12 °C water for 12 min. The control pig was treated normally except for the same delay before batch chilling commenced. The initial pH fall in LD and BF did not depend on the glycolytic potential in LD but at 5 to 6 and 24 hr post mortem pigs with the lowest glycolytic potential had the highest pH. Weight and lean meat content did not affect the cooling curve, i.e. the temperature fall. The results showed that it was possible to reduce the temperature in BF and LD by cooling at slaughter. The maximum difference in temperature between control and cooled carcasses 2hr post mortem was 2 and 1 °C in LD and BF respectively. The lowering of the muscle temperature early post mortem resulted in a reduced rate of the pH fall and a higher pH from 2 to 6 hr in the cooled carcasses. The rate of the pH fall in LD and BF seemed to be independent of temperature at levels above approximately 37 °C, but decreased linearly as the temperature dropped below approximately 37 °C. The cooling procedure used here did not result in a significant reduction in protein denaturation or drip loss, although there was a tendency towards lower drip loss in LD and BF in cooled carcasses.     

Thermal, productive, and reproductive responses of high yielding cows exposed to short-term cooling in summer

Effect of cooling on body temperature, milk production, estrous behavior, and reproductive performance was examined in 66 estrous-synchronized, Israeli-Holstein dairy cows. Cooling was by an automated system, which actuated sprinkling (30 s) followed by forced ventilation (4.5 min) for 30-min periods. Cows were cooled 9 times/d between 0500 and 2100 h over 10 d, starting 1 d before expected estrus until d 8 post estrus. Cooling reduced typical diurnal rise of body temperature in summer heat-stressed cows by .5 to .9 degrees C, and body temperature was maintained close to normothermic temperature (38.6 degrees C). Milk production of cooled cows was 2.6 kg/d (+8%) above control at end of the cooling period. More cooled cows than noncooled exhibited standing estrous behavior; in noncooled cows, silent ovulations or anestrus were more frequent. Conception rate of cooled cows did not differ from control, suggesting need for a longer than a 10-d cooling period for improvement of fertility. The cooling system has potential to alleviate heat stress in dairy cows and to improve their thermal balance, productive, and reproductive performances.     

后纺风机水帘降温系统控制与管理方法

通过对后纺风机水帘降温系统工作原理的分析,阐述水帘降温系统对后纺生产状态的影响,提出风机水帘降温系统的控制方法及管理方法,以满足后纺的生产工艺要求。     

井式炉的结构和维护方法

介绍球化退火井式炉的基本结构,对自预热燃烧器的结构和工作原理进行详述。提出设备重要部件如内筒及对流筒、炉底搅拌风扇、温控和电控系统维护过程中需要注意的问题。在井式炉使用过程中除了检查循环冷却水、炉底搅拌风扇、气氛压力、炉体密封、热电偶等是否正常外,应及时对甲醇裂解炉和甲醇裂解气管道进行除炭。在使用和维护时,应及时检查炉体的密封状况和设备机械传动件的润滑情况,控制进炉物料数量,保证井式炉工艺稳定。     

Physiological, productive, and economic benefits of shade, spray, and fan system versus shade for Holstein cows during summer heat

During the 1984 summer, effects of spray and fan in freestall areas and feeding areas on milk yield, plasma growth hormone and prolactin, freestall utilization, and economic significance for Holstein cows were studied. Weekly milk and rectal temperatures at morning and afternoon milkings were higher for cows in shade than in shade with spray and fan cooling. Compared with rectal temperature, milk temperature measured in the clawpiece provided a more reliable indicator of heat stress than in the milk meter. Diurnal pattern of rectal temperature from 4-h measurements showed an average of 12 h in which maximal rectal temperatures of cows in shade were greater than 39 degrees C, but cows in the shade plus spray plus fan group had rectal temperatures below 39 degrees C all day. Plasma growth hormone was higher and prolactin lower for cows in shade plus spray and fan than cows in shade only. Cows cooled with spray and fan under shade produced 2 kg/cow per d more than cows in shade alone. Economic analysis showed a net income of 22 cents/cow per day for spray plus fan under shade. Results suggest that milk temperature is a practical technique to assess heat stress in dairy cattle, and the use of spray plus fan is a profitable means to maximize cow comfort and lessen stress-induced decline in milk production.     

顺流式玉米烘干塔温度控制系统开发与改进

为有效保证粮食的烘干温度保持在设定的安全温度范围之内,采用多传感器均匀布点检测与模糊控制技术,设计一种顺流式玉米烘干塔温度控制系统。以AT89C51单片机为开发平台,利用可编程温度传感器DS18B20,通过串口通信传输至LabVIEW系统上位机显示,并以检测的温度数据作为系统调节反馈,采用抗饱和PID控制算法,调节单片机输出占空比的大小,从而使驱动电路控制热风机的转速。与传统装置相比,改进后的温度控制系统具有主机接口简单、结构灵活、调试方便、测温系统转换速度快、精度高的特点。     

SIMULATION OF THE EVAPORATIVE COOLING PROCESS FOR TORTILLAS

A simulation model was developed to predict temperature, moisture content and water activity of evaporatively cooled tortillas. The overall model was based on three parts: (1) the predicted equilibrium moisture isotherm for the product, (2) a correlation model for predicting the saturated water vapor pressure for a given temperature, and (3) the energy and mass balances for simultaneous convective heat and moisture transfer between product and cooling air. The simulation model was verified with experimental data and was found to accurately describe the behavior of the tortilla cooling system. The model predicted the simultaneous decrease in temperature, moisture content, and water activity of the product exposed to varying simulated processing conditions. It was found that cooling air velocity and temperature had the primary effect on product cooling and moisture loss rates.