空调用蒸发式冷凝器数值模拟与结构优化

发布时间：2018-06-25 07:00

  本文选题：蒸发式冷凝器 + 强化换热　； 参考：《长沙理工大学》2013年硕士论文

【摘要】：空调能耗是建筑能耗的重要组成部分，约占整个建筑能耗的50%左右，并有逐年增加的趋势，因此降低空调机组的能耗是非常重要的。冷凝器是空调机组中主要的热交换设备，其运行特性将直接影响空调机组的性能及运行的经济性，增强冷凝器的换热效果，会促使整个空调机组的COP提高，从而降低空调机组的能耗。目前，冷凝器有空冷式、水冷式和蒸发式三种类型，蒸发式冷凝器相对于其它形式的冷凝器具有换热效率高、节水及结构紧凑等特点而受到了广泛关注，这为深入分析蒸发式冷凝器的换热特性及合理设计提供了理论依据。 本文对蒸发式冷凝器的传热传质机理进行了分析，建立了蒸发式冷凝器的三维物理模型，通过数值模拟研究了冷凝器结构对蒸发式冷凝器换热性能的影响以及冷凝器温度场和速度场的分布规律，并对其结构进行优化，从而得出以下结论： （1）在同种条件下，圆形截面喷嘴的换热性能优于方形截面喷嘴； （2）当喷嘴间距为100mm～200mm和管束区管间距为12mm～28mm时，通过对喷淋水速度、喷淋水温度与换热量关系的研究，得出当喷淋水速度为1.8m/s、喷淋水温度为30℃时，换热量达到最大值； （3）通过对冷凝器温度场、速度场和换热量的模拟研究，得出当喷嘴间距为200mm、喷淋水速度为1.8m/s、喷淋水温度为30℃、喷嘴到管束区首排管束距离为200mm、管束区管间距为16mm时，温度场和速度场分布都比较理想，此时换热效果较好，单位面积换热量为92.36kW/m2； （4）利用软件中DPM模型分析了在上述情况下的液滴分布规律，得到当喷嘴间距为200mm、喷嘴到管束区首排管束距离为200mm、管束区管间距为16mm时，液滴可以较好的均匀覆盖在换热盘管的表面，，说明此种情况下蒸发换热效果较好。
[Abstract]:Air conditioning energy consumption is an important part of building energy consumption, about 50% of the total building energy consumption, and has a trend of increasing year by year, so it is very important to reduce the energy consumption of air conditioning units. Condenser is the main heat exchange equipment in the air conditioning unit. Its operation characteristics will directly affect the performance and operation economy of the air conditioning unit, enhance the heat transfer effect of the condenser, and promote the cop of the whole air conditioning unit. Thus, the energy consumption of the air conditioning unit is reduced. At present, there are three types of condensers: air-cooled, water-cooled and evaporative. The evaporative condenser has been widely concerned because of its high heat transfer efficiency, water saving and compact structure. This provides a theoretical basis for in-depth analysis of heat transfer characteristics and rational design of evaporative condensers. In this paper, the heat and mass transfer mechanism of evaporative condenser is analyzed, and the three-dimensional physical model of evaporative condenser is established. The influence of condenser structure on the heat transfer performance of evaporative condenser and the distribution of temperature field and velocity field of condenser were studied by numerical simulation, and its structure was optimized. The conclusions are as follows: (1) under the same conditions, the heat transfer performance of circular section nozzle is better than that of square section nozzle, (2) when the nozzle spacing is 100mm~200mm and the tube spacing of tube bundle is 12mm~28mm, Through the study of the relationship between spray water velocity, spray water temperature and heat transfer, the maximum heat transfer is obtained when the spray water velocity is 1.8 m / s and the spray water temperature is 30 鈩

本文编号：2065073