蒸发式空气加湿冷却器的性能及其在风冷冷水机组中的应用

通过对采用铝质孔板波纹填料的直接蒸发式空气加湿冷却器的测试,给出了蒸发冷却效率,空气阻力与迎面风速,淋水密度之间的关系式和曲线,并分析了该设备用于风冷冷水机组的效果和经济性。     

金属填料直接蒸发式空调机性能研究

对铝箔金属填料直接蒸发冷却空调机进行了实验研究。分析了进口空气干球温度、相对湿度对空调机降温及冷却效率的影响,为直接蒸发冷却式空调机性能的提高具有一定的参考意义。     

应用于兰州的直接蒸发冷却空调性能测试分析

本文测试了兰州市内一台金属填料直接蒸发冷却器,获得了干湿球温度、相对湿度、冷却效率、阻力等技术参数。分析了进口处空气干球温度和相对湿度对蒸发冷却效率的影响,发现被测试的机组蒸发冷却效率较低,蒸发冷却段阻力较大,因此,需要改善设计。由于兰州属于干燥地区,因此通过优化设计,蒸发冷却效率有提升的空间。     

复合型横流闭式冷却塔冷却特性的实验研究

为了探讨风冷蒸发复合型横流闭式冷却塔不同连接方式对其冷却性能的影响,搭建了风冷蒸发复合型横流闭式冷却塔模型实验系统,开展了复合型塔在风冷翅片管与蒸发冷光盘管串联与并联时冷却性能的实验研究.实验结果表明,并联式复合型冷却塔冷却性能随着空气流量,喷淋水流量及气水比的增加而增强,与串联式相比,其受这三个参数的影响更小.冷却水流量的增大使得串联式与并联式的冷却效率均减小,其对并联式的影响更大.在其他工况相同的情况下,串联式复合型横流闭式冷却塔的冷却效率比并联式高3.5％～9％.     

复合型横流闭式冷却塔冷却特性的实验研究

为了探讨风冷蒸发复合型横流闭式冷却塔不同连接方式对其冷却性能的影响,搭建了风冷蒸发复合型横流闭式冷却塔模型实验系统,开展了复合型塔在风冷翅片管与蒸发冷光盘管串联与并联时冷却性能的实验研究.实验结果表明,并联式复合型冷却塔冷却性能随着空气流量,喷淋水流量及气水比的增加而增强,与串联式相比,其受这三个参数的影响更小.冷却水流量的增大使得串联式与并联式的冷却效率均减小,其对并联式的影响更大.在其他工况相同的情况下,串联式复合型横流闭式冷却塔的冷却效率比并联式高3.5％～9％.     

直接蒸发冷却空调机性能研究

分析了影响直接蒸发冷却空调机性能的因素,然后对天然植物纤维填料式直接蒸发冷却空调机性能进行了实验研究并获得了相关性能曲线。研究结果表明,直接蒸发冷却空调机在我国西北干旱和半干旱地区降温加湿效果很好,完全可以达到舒适性要求,是一种节能的绿色空调;天然植物纤维填料阻力较大,但降温加湿效果更好。     

直接蒸发冷却在配电间及变频器室的应用潜力

本文结合直接蒸发冷却系统的空气处理过程,研究了直接蒸发冷却技术在火电厂配电间及变频器室中的适用性。并以某工程为例,分析了室内设计温度和直接蒸发冷却机组的效率对机组运行成本的影响。结果表明:1)适合在火力发电厂配电间及变频器室应用直接蒸发冷却系统的国内区域较多。2)提高室内设计温度,能够明显降低系统的送风量和机组所需的冷却水量。3)提高直接蒸发冷却机组效率,能在一定程度上降低系统的送风量,但对冷却水量的影响不大。     

蒸发式风冷冷水机组年运行节能潜力研究

介绍了蒸发式风冷冷水机组的能耗模型,通过选取具有代表性城市的全年气象参数,分析了蒸发式风冷冷水机组在不同气候条件、不同直接蒸发冷却器填料厚度、不同运行风速下的年运行节能潜力,获得了一些具有参考价值的分析数据,为蒸发式风冷冷水机组的节能设计和推广使用提供了参考数据。     

多孔陶瓷填料直接蒸发冷却器性能分析

通过对目前常用的直接蒸发冷却器填料进行对比分析,提出了采用多孔陶瓷填料的直接蒸发冷却器。并对多孔陶瓷材料的应用现状进行了研究,同时分析了多孔陶瓷填料直接蒸发冷却器的特点,指出多孔陶瓷材料在直接蒸发冷却器中的应用是一种必然的发展趋势。最后提出多孔陶瓷间接蒸发冷却器与直接蒸发冷却器复合的二级蒸发冷却系统,其冷却效果更逼近露点。     

干燥地区某地铁站直接蒸发冷却通风降温试验样机的性能测试与分析

为了研究直接蒸发冷却通风降温机组在干燥地区某地铁站中的应用效果,制作了一台直接蒸发冷却通风降温机组试验样机。采用理论计算与测试相结合的方法,对试验样机的风量、直接蒸发冷却效率、空气温降及阻力进行了试验研究。对比了4种方案下试验样机的冷却效果及阻力情况,得出在300mm厚填料三维布水、淋水密度6 000kg/(m~2·h)和迎面风速2.2m/s的情况下,试验样机的直接蒸发冷却效率达99%。     

On-site experimental testing of a novel dew point evaporative cooler

Technologies which utilise the advantages of evaporative cooling to reduce the temperature of air without the addition of moisture have existed for some time. These systems use a heat exchange media between the evaporation of water process and cooling of air. Research has been conducted on a number of systems utilising these technologies in various configurations and it has been demonstrated that temperatures of the incoming air can approach its dew point temperature. This is considerably lower than the wet bulb temperature which is the limit achieved with conventional direct evaporative cooling systems. Prototypes have been built to demonstrate the principles and temperatures achievable, but the technology has never been developed due to its high cost and complexity. These disadvantages have been addressed in a newly developed indirect evaporative cooler. The paper presents results obtained from testing a prototype cooler installed in both a commercial and residential application in a wide range of ambient conditions. The performance characteristic of the indirect evaporative cooler in regards to its outlet temperatures and electrical energy efficiency is presented.     

Development and testing of two-stage evaporative cooler

Evaporative cooling has been proved as an effective method of storage of fruits and vegetables of moderate respiration rates. Therefore, a modified evaporative cooler named two-stage evaporative cooler (TSEC) has been developed to improve the efficiency of evaporative cooling for high humidity and low temperature air conditioning. Two-stage evaporative cooler consists of the heat exchanger and two evaporative cooling chambers. The performance of cooler has been evaluated in terms of temperature drop, efficiency of the evaporative cooling and effectiveness of TSEC over single evaporation. The temperature drop through TSEC ranged from 8 to 16 °C. With the several observations for diurnal runs, it was observed that TSEC could drop the temperature up to wet bulb depression of ambient air and provided the 90% relative humidity. Efficiency of single evaporation was 85–90%. Effectiveness of the two-stage evaporative cooling was found to be 1.1–1.2 over single evaporation. The two-stage evaporative cooler provided the room conditions as 17–25 °C temperature and 50–75% relative humidity, which can enable to enhance the shelf-life of wide range of fruit and vegetables of moderate respiration rates.     

燃气驱动的三级液体除湿空调系统及其特点分析

介绍了液体除湿空调系统的原理及其特点。基于分级除湿思想和能量梯级利用原则，提出了一种燃气驱动的三级液体除湿空调系统，系统由风机、除湿器、蒸发冷却器和再生器组成。除湿器采用三级液体除湿，通过对室内回风直接蒸发冷却进行全热回收，用回收的冷量冷却除湿过程，移去处理空气的潜热；蒸发冷却器由间接蒸发冷却器和直接蒸发冷却器两部分组成，前者间接冷却除湿后的空气，移去空气的显热，后者调节空气的温湿度；再牛器采用燃气驱动，实现沸腾蒸发和非沸腾蒸发结合的两效再生。该系统是一种节能环保的新型空凋系统，具有优化城市能源结构的功能。     

四级蒸发冷却组合式空调机组能耗分析

以西安地区的1台50 000m3/h风量的四级蒸发冷却机组为例,通过实际测定所获得的各段效率,将有关数据用于该四级蒸发冷却机组的能耗计算与分析,得到了在额定工况下该空调机组的能效比,为蒸发冷却空调机组在西安等中湿度地区的应用提供了参考依据.     

Water-use efficiency for alternative cooling technologies in arid climates

In arid climates, evaporative cooling technologies are generally valued for their reduced energy consumption in comparison to compressor-based air conditioning systems. However, two concerns that are often raised with respect to evaporative cooling equipment are their on-site water use and the impact of poor water quality on their performance. While compressor-based systems do not use water on-site, they do consume water through their use of electricity, which consumes water through evaporation at hydroelectric power plants and cooling at thermal power plants. This paper defines a water-use efficiency metric and a methodology for assessing the water use of various cooling technologies. The water-use efficiencies of several example cooling technologies are compared, including direct evaporative, indirect evaporative in two different configurations, compressor-based systems, compressor-based systems with evaporative pre-cooling of condenser inlet air, and hybrid systems that consist of an indirect evaporative module combined with a compressor-based module. Designing cooling systems for arid climates is entwined in the close relationship between water and energy and the scarcity of both resources. The analyses presented in this paper suggest that evaporative systems that significantly reduce peak electricity demand and annual energy consumption need not consume any more water than conventional systems.     

A two-stage system of nocturnal radiative and indirect evaporative cooling for conditions in Tehran

In this paper, the results of an investigation on a two-stage cooling system have been studied. This system consists of a nocturnal radiative unit, a cooling coil, and an indirect evaporative cooler. During the night in summer, requisite chilled water for a cooling coil unit is provided by nocturnal radiative cooling and is stored in a storage tank. During the next day, the water in the tank provides chilled water for the cooling coil unit and hot outdoor air passes through two-stages: the cooling coil unit and an indirect evaporative cooler. Three sources provide secondary air for the indirect evaporative cooler. The sources are outdoor air, the air leaving from the cooling coil, and the air leaving from the indirect stage (regenerative). The investigation has been conducted in weather conditions in the city Tehran. The results obtained demonstrate that the first stage of the system increases the effectiveness of the indirect evaporative cooler. Also, the regenerative model provides the best comfort conditions. Therefore, this environmentally friendly and energy-efficient system can be considered as an alternative to the mechanical vapor compression systems.     

干热地区蒸发制冷空调设计

该工程为新疆某图书馆,功能复杂,夏季空调冷源采用间接蒸发冷水机组,末端采用风机盘管加新风系统,新风机组采用间接蒸发冷却器+直接蒸发冷却器型式;冬季采用低温地板辐射采暖.本文主要介绍夏季蒸发制冷空调设计.     

Investigation of a hybrid system of nocturnal radiative cooling and direct evaporative cooling

In this paper, the results of a study on a hybrid system of nocturnal radiative cooling, cooling coil, and direct evaporative cooling in Tehran have been discussed. During a night, the nocturnal radiative cooling provides required chilled water for a cooling coil unit. The cold water is stored in a storage tank. During eight working hours of the next day, hot outdoor air is pre-cooled by means of the cooling coil unit and then it enters a direct evaporative cooling unit. In this period, temperature variation of the conditioned air is investigated. This hybrid system complements direct evaporative cooling as if it consumes low energy to provide cold water and is able to fulfill the comfort condition whereas direct evaporative alone is not able to provide summer comfort condition. The results obtained demonstrate that overall effectiveness of hybrid system is more than 100%. Thus, this environmentally clean and energy efficient system can be considered as an alternative to the mechanical vapor compression systems.     

椭圆管蒸发冷却器冷却性能的影响因素分析

椭圆管蒸发冷却器具有管子排列紧凑,空气流动阻力小等优点,在高性能的闭式冷却塔内有着广泛应用.本文首先分析了结构参数对椭圆管蒸发冷却器冷却性能的影响,然后分析了运行参数对其冷却性能的影响,通过分析得到了一些有价值的结论,为管式蒸发冷却器的优化设计及运行提供了参考依据.