以结霜工况下的变片距空气冷却器为研究对象,对空气冷却器建立分布参数计算模型,采用分子扩散理论建立霜层的生长模型。在计算过程中,采用空气冷却器迎风面的霜层厚度平均值作为变量迭代求解空气冷却器的风量。研究了变翅片间距结构对空气冷却器结霜工况下性能的影响,并进行了实验验证。实验结果表明：空气冷却器的风量、换热量变化趋势的实验值和计算值基本一致,偏差在5%左右。与定翅片间距空气冷却器相比,变翅片间距空气冷却器在结霜工况下具有较长的除霜周期和更好的传热性能。

A two-dimensional transient model for frost formation phenomenon on an air cooler with variable fin pitch has been developed to calculate and optimize the performance of the air cooler under frosting conditions.The proposed model is based on the molecular diffusion model.In the model,the mean frost thickness at the windward side of the control volume of the evaporator is taken as a variable for iterative calculations of the air volumetric flow rate to improve numerical accuracy. The numerically and experimentally obtained performance of the air cooler with variable fin pitch and constant fin pitch was compared.The results show a good agreement between the calculated values and the experimental data of the volumetric flow rate and the heat transfer rate of the air cooler with the relative difference less than 5%.Compared to air coolers with constant fin pitch under the same operating condition,the decrease in the volumetric flow rate of the air cooler with variable fin pitch i

以管式间接蒸发冷却器实验台为依托,着重对其传热传质过程进行分析与计算.合理设置实验台初始状态参数,测试管式间接蒸发冷却器在兰州地区气候条件下的实际应用效果.在获得理想实验数据后,通过查阅文献选择误差范围较小的传热传质关联式,计算出换热过程中主要技术参数,为今后在兰州地区气候条件下制造出适用性更高的管式间接蒸发冷却器提供较为可靠的理论设计依据,并进一步证明在空气能比较丰富的西北地区管式间接蒸发冷却器推广应用大有前景.

The heat and mass transferring are analyzed and calculated with the tubular indirect evaporative cooler experiment table. The reasonable initial parameter for experiment table is set up to test the actual operation effect of the tubular indirect evaporative cooler in Lanzhou climate. After obtaining ideal experimental data, the heat and mass transfer correlations with small error are selected through the lit-erature, calculating main technical parameters in the heat exchange process. It will provide reliable theoretical design guidelines for producing tubular indirect evaporative cooler of highly practical value in the future in Lanzhou climate conditions, and further prove that application and dissemination of the tubular indirect evaporative cooler features for promising outlook in the air-rich northwest district.

铜冶炼生产环境中,高浓度腐蚀性气体会导致离心压缩机主要零部件腐蚀。为此,某厂加装了具有化学过滤功能的空气过滤器,并对冷却器芯进行了国产化应用实践,取得了良好效果。

During the production environment of copper smelting,high concentration corrosive gas may result in main components of centrifugal compressor being corroded. As for these problems, air filter with function of chemical filtration was added in a plant and detailed measures were conducted on application of local production of cooler core, and got good effect.

通过在锅炉空气预热器出口的热一次风道内安装换热装置,可以降低预热器出口热一次风温,从而可以减少直吹式制粉系统冷风的用量,降低了锅炉排烟温度。这种方法充分利用了制粉系统的富余干燥出力,达到降低机组煤耗的目的。通过分析中速磨直吹式制粉系统的工作特点,介绍了一次风冷却器降低燃煤机组煤耗的工作原理,并对安装一次风冷却器后,制粉系统的运行控制方式进行介绍。最后讨论了安装一次风冷却器的节能潜力,并指出影响其节能效果的主要因素。

By installing a heat exchanger in the boiler air preheater hot primary air duct,the hot primary air temperature will be lowered,the cold primary air will be reduced and boiler exhaust temperature will be low-ered.This method makes full use of the surplus of drying capacity of coal pulverizing system,to reduce the unit coal consumption.This paper analyzed the characteristics of medium speed mill direct blowing coal pulver-izing system,and introduced the principle of primary air cooler to reduce coal consumption of the coal burning unit,and the operation and control mode of pulverizing system were introduced after installation of a primary air cooler.Finally the energy-saving potential of using the primary air cooler was discussed,and it was pointed out that the main factors affecting its energy-saving effect.

为了优化结霜工况下翅片管式空气冷却器的结构设计,提出经济性分析计算模型。综合考虑换热性能、材料成本及运行费用,以单位制冷量的费用年值为目标函数,以费用年值最小为优化目标求解经济模型得到合理的空气冷却器的结构参数,分析了翅片间距、换热管管径、管排数变化对目标函数的影响,并通过一冷库案例进行实际测试验证。计算及试验结果表明:随着翅片间距的增大,目标函数先减小后增大,翅片间距为10时目标函数取极小值;在相同翅片间距的情况下管径越大,其目标函数值也越大;综合考虑换热管直径、翅片间距和管排数的影响,翅片间距为10,换热管外径为9.52,管排数为6时,目标函数取极小值。

Inthepresentstudy,aneconomicanalysismodeloffinandtubeaircoolerunderfrostingconditionwasproposedby considering the heat transfer performance,material costs and the energy consumption.Annual cost of refrigerating capacity per W was set as the objective function;the minimum of the objective function was set as an optimization goal.To solve the model and get the reasonable structural parameters of the air cooler,and analyzes the influence of the structural parameters such as fin pitch,heat exchange tube diameter to the objective function,and verify the model by testing in a cold storage.The experimental and calculat-ed results show that:with the fin pitch increases,the objective function first decreases and then increases,and gets a minimum val-ue when fin pitch is 10mm.With the same fin pitch,the greater of tube diameter,and the greater value of the objective function. By considering the fin pitch,heat exchange tube diameter and tube row number,the objective function value is minimum when