两侧旋转布水间接蒸发冷却器关键参数实验研究
发布时间：2018-11-21 17:49
【摘要】：由于地铁沿线都是城市繁华区域和主干道,很难在地铁站外地面上找到既与周边环境协调,又满足地铁站空调系统冷却塔安装环境的安装位置,因此,研究一种换热效率高、适于地铁等地下建筑的专用冷却器来替代目前常用的冷却塔,具有重要的工程应用价值。本文在两侧旋转布水间接蒸发冷却器理论研究的基础上,开发了机械传动装置以实现换热器两侧旋转布水,并搭建了两侧旋转布水间接蒸发冷却器性能测试实验台,研究了各参数对其性能的影响,为地铁专用冷却器的开发提供依据。通过实验研究喷嘴与换热器间距、双组换热盘管间距、单双侧旋转布水对换热器性能的影响,以及设计正交实验,研究换热器分别为单组、双组时,在三种布置方式下,喷水量、转速、空气温度、管内冷却水流量、冷却水进口温度等因素对换热器传热传质性能的影响,实验结果表明：(1)换热器两侧旋转布水时与单侧相比,换热器垂直气流布置时换热量提高了30.8%,平行气流布置时提高了20%。同时,在上述两种布置方式下,喷嘴到换热器间距、双组换热盘管间距对其性能影响较小。(2)单组换热器垂直气流布置时,空气速度由2.5m/s增至3m/s时,换热量先增加至0.602kw/m2(即空气速度为2.75m/s)后保持不变,冷却水流量由400L/h增至600L/h时,换热量先减少至0.595kw/m2(即冷却水流量为500L/h)后不变；双组换热器垂直气流布置时,随着布水装置转速、冷却水流量的增大,换热量呈现先减少后增加的趋势,同时还表明,双组布置时的换热量与单组布置时相比增加了1.96%。(3)单组、双组换热器平行气流布置时,双组换热器时的冷却水流量的增大使换热量呈现先减少后增加的趋势,且双组换热器的换热性能比单组布置时提高了17.4%。(4)单组换热器中心开孔正对气流布置时,转速由50r/min增至100r/min时,换热量呈现先减少后增加趋势;双组布置时,转速的增加使换热量先增加至0.991 kw/m2后减少,即存在最佳转速76r/min。单组换热器布置时的换热量比双组时提高了16.67%。(5)在不同布置方式下各因素对换热器性能影响的主次顺序各不相同,同时,三种布置方式中,换热器中心开孔正对气流布置时换热器换热性能最佳。
[Abstract]:As there are busy urban areas and main roads along the subway line, it is difficult to find a location on the ground outside the subway station that not only coordinates with the surrounding environment, but also meets the installation environment of the cooling tower of the subway air conditioning system. Therefore, the study of a kind of heat transfer efficiency is high. Special coolers suitable for underground buildings such as subway have important engineering application value to replace the commonly used cooling towers. Based on the theoretical research of indirect evaporative cooler with two sides of rotating water distribution, a mechanical transmission device is developed to realize the rotating distribution of water on both sides of the heat exchanger, and a test bench for testing the performance of the indirect evaporative cooler with two sides of rotating water distribution is built. The influence of various parameters on its performance is studied, which provides the basis for the development of special cooler for subway. The effects of the distance between nozzle and heat exchanger, the distance between two groups of heat transfer coils and the rotating water distribution on the performance of the heat exchanger were studied by experiments. The orthogonal design experiment was carried out to study the effect of the heat exchanger on the performance of the heat exchanger under three different arrangement modes, when the heat exchanger was divided into single group and double group. The effects of water injection rate, rotational speed, air temperature, cooling water flow rate and inlet temperature of cooling water on the heat and mass transfer performance of the heat exchanger are discussed. The experimental results show that: (1) when the water distribution is rotated on both sides of the heat exchanger, it is compared with the one side. The heat transfer increased by 30.8 when the vertical flow was arranged, and by 20 when the parallel flow was arranged. At the same time, the distance between nozzle and heat exchanger and the distance between two groups of heat exchanger coils have little effect on the performance of the two kinds of arrangement. (2) when the vertical flow of single heat exchanger is arranged, the air velocity increases from 2.5m/s to 3m/s. When the cooling water flow rate increased from 400L/h to 600L/h, the heat transfer decreased to 0.595kw/m2 (that is, the cooling water flow rate was 500L/h) and then remained unchanged after the increase of heat transfer to 0.602kw/m2 (that is, air velocity is 2.75m/s). When two heat exchangers are arranged in vertical air flow, with the increase of cooling water flow rate and the speed of water distribution unit, the heat transfer appears to decrease first and then increase. At the same time, it is also shown that, Compared with the single group arrangement, the heat transfer increased by 1.96. (3) the cooling water flow increased with the increase of the cooling water flow in the two groups of heat exchangers, and the heat exchange decreased first and then increased. The heat transfer performance of the two-group heat exchanger is 17.4% higher than that of the single group heat exchanger. (4) when the center opening of the single group heat exchanger is arranged to the airflow, when the rotational speed increases from 50r/min to 100r/min, the heat transfer rate decreases first and then increases; With the increase of rotational speed, the heat transfer increased to 0.991 kw/m2 and then decreased, that is, the optimum rotation speed was 76 r / min. The heat transfer of single heat exchanger is 16.67767 higher than that of double heat exchanger. (5) the primary and secondary order of the influence of each factor on heat exchanger performance is different under different arrangement modes, meanwhile, among the three arrangement modes, The heat exchanger has the best heat transfer performance when the center of the heat exchanger is open to the airflow.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU962
本文编号：2347778
[Abstract]:As there are busy urban areas and main roads along the subway line, it is difficult to find a location on the ground outside the subway station that not only coordinates with the surrounding environment, but also meets the installation environment of the cooling tower of the subway air conditioning system. Therefore, the study of a kind of heat transfer efficiency is high. Special coolers suitable for underground buildings such as subway have important engineering application value to replace the commonly used cooling towers. Based on the theoretical research of indirect evaporative cooler with two sides of rotating water distribution, a mechanical transmission device is developed to realize the rotating distribution of water on both sides of the heat exchanger, and a test bench for testing the performance of the indirect evaporative cooler with two sides of rotating water distribution is built. The influence of various parameters on its performance is studied, which provides the basis for the development of special cooler for subway. The effects of the distance between nozzle and heat exchanger, the distance between two groups of heat transfer coils and the rotating water distribution on the performance of the heat exchanger were studied by experiments. The orthogonal design experiment was carried out to study the effect of the heat exchanger on the performance of the heat exchanger under three different arrangement modes, when the heat exchanger was divided into single group and double group. The effects of water injection rate, rotational speed, air temperature, cooling water flow rate and inlet temperature of cooling water on the heat and mass transfer performance of the heat exchanger are discussed. The experimental results show that: (1) when the water distribution is rotated on both sides of the heat exchanger, it is compared with the one side. The heat transfer increased by 30.8 when the vertical flow was arranged, and by 20 when the parallel flow was arranged. At the same time, the distance between nozzle and heat exchanger and the distance between two groups of heat exchanger coils have little effect on the performance of the two kinds of arrangement. (2) when the vertical flow of single heat exchanger is arranged, the air velocity increases from 2.5m/s to 3m/s. When the cooling water flow rate increased from 400L/h to 600L/h, the heat transfer decreased to 0.595kw/m2 (that is, the cooling water flow rate was 500L/h) and then remained unchanged after the increase of heat transfer to 0.602kw/m2 (that is, air velocity is 2.75m/s). When two heat exchangers are arranged in vertical air flow, with the increase of cooling water flow rate and the speed of water distribution unit, the heat transfer appears to decrease first and then increase. At the same time, it is also shown that, Compared with the single group arrangement, the heat transfer increased by 1.96. (3) the cooling water flow increased with the increase of the cooling water flow in the two groups of heat exchangers, and the heat exchange decreased first and then increased. The heat transfer performance of the two-group heat exchanger is 17.4% higher than that of the single group heat exchanger. (4) when the center opening of the single group heat exchanger is arranged to the airflow, when the rotational speed increases from 50r/min to 100r/min, the heat transfer rate decreases first and then increases; With the increase of rotational speed, the heat transfer increased to 0.991 kw/m2 and then decreased, that is, the optimum rotation speed was 76 r / min. The heat transfer of single heat exchanger is 16.67767 higher than that of double heat exchanger. (5) the primary and secondary order of the influence of each factor on heat exchanger performance is different under different arrangement modes, meanwhile, among the three arrangement modes, The heat exchanger has the best heat transfer performance when the center of the heat exchanger is open to the airflow.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU962
【参考文献】
相关硕士学位论文 前1条
1 沈家龙;蒸发式冷凝器传热传质理论分析及实验研究[D];华南理工大学;2005年
，本文编号：2347778
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