风冷冷水机组群和空调送风管气流组织的数值模拟与优化

发布时间：2018-06-19 14:06

本文选题：风冷冷水机组 + 气流组织　；参考：《长沙理工大学》2014年硕士论文

【摘要】：近年来,随着高层高端建筑与大型城市综合体的大量涌现,中央空调系统的布置也变得更为复杂。空调冷热源和空调送风系统是中央空调系统的重要组成部分,它们的合理设计与布置对空调系统的使用效果、室内空气品质和节能有着重要的意义。然而,目前空调冷热源和空调送风系统的设计与布置普遍采用经验的方法,造成空调冷热源与空调送风系统不能很好达到设计要求。本文首先对风冷冷水机组群自然排风情况下设备层内气流组织进行了数值模拟,结果表明风冷冷水机组设备层内的气流分布较紊乱,室外气流不能顺畅地进入设备层,且风冷机组的高温排风出现返混现象,严重地影响着风冷冷水机组的换热性能。其次,针对自然排风情况下风冷冷水机组设备层气流组织的不足,提出采用“有组织排风”的方法改进设备层内的气流组织情况的优化设计方案,并数值模拟了优化方案下风冷冷水机组设备层内气流组织分布,并比较了“有组织排风”优化方案与“自然排风”方案,结果表明优化方案下风冷冷水机组设备层内的气流组织情况有所改善,风冷冷水机组群的高温排风在排风管和排风箱的组织下顺利排到室外,有效地阻止了高温排风的返混,同时,室外的气流也能够顺利地进入设备层内,确保风冷冷水机组能够高效稳定的运行。最后,以办公室标准层全空气空调送风系统为研究对象,对空调送风管和末端的速度、压力和出口流量进行了数值模拟,模拟结果表明办公室标准层变风量全空气空调系统的送风系统设计较合理,送风支管内速度和压力分布较均匀,末端各个风口送风量偏差较小。但通过对各末端设备所负责区域的出口送风量和设计要求的送风量比较分析,发现东西两侧的空调机组在末端设备风阀全开的情况下各区域的送风量均不能满足设计要求。因此,建议空调系统实际运行时,减小送风量偏大区域内末端设备的阀门开度,确保各送风口送风量的均匀性。本文的研究结果对空调系统方案的优化具有重要的指导意义,同时对其它同类大型建筑的空调系统设计具有借鉴意义。
[Abstract]:In recent years, with the emergence of high-rise high-end buildings and large-scale urban complexes, the layout of central air-conditioning systems has become more complex. Air conditioning cooling and heating sources and air supply system are important parts of central air conditioning system. Their reasonable design and arrangement are of great significance to the use effect of air conditioning system, indoor air quality and energy saving. However, at present, the design and arrangement of air conditioning cooling and heating sources and air supply systems of air conditioning generally adopt the method of experience, which results in the air conditioning cold and heat sources and air supply systems can not meet the design requirements well. In this paper, the airflow distribution in the equipment layer of air-cooled chillers is numerically simulated under the condition of natural exhaust air flow. The results show that the airflow distribution in the air-cooled chillers' equipment layer is more disordered, and the outdoor airflow can not enter the equipment layer smoothly. The backmixing of high temperature exhaust air of air-cooled chillers seriously affects the heat transfer performance of air-cooled chillers. Secondly, aiming at the shortage of airflow organization in the air cooled chiller under natural exhaust, the paper puts forward an optimized design scheme to improve the airflow distribution in the equipment layer by using the method of "organized exhaust air". The airflow distribution in the air cooled chiller layer under the optimized scheme is numerically simulated, and the optimization scheme of "organized exhaust air" and the "natural exhaust air" scheme are compared. The results show that the airflow organization in the equipment layer of air-cooled chillers has been improved, and the high-temperature exhaust air of air-cooled chillers has been successfully discharged outdoors under the organization of exhaust pipes and exhaust boxes, which effectively prevents the backmixing of high-temperature exhaust air. At the same time, the outdoor air flow can enter the equipment layer smoothly, to ensure the air-cooled chillers can run efficiently and stably. Finally, the velocity, pressure and outlet flow rate of the air supply duct and the end of the air conditioning system are numerically simulated, taking the air supply system of the standard layer of the office air conditioning system as the research object. The simulation results show that the design of the air supply system of the office standard layer VAV total air conditioning system is more reasonable, the velocity and pressure distribution in the air supply branch pipe is more uniform, and the deviation of the air supply volume at the end of each tuyere is relatively small. However, through the comparative analysis of the outlet air supply volume and the design requirement of each terminal equipment, it is found that the air supply volume of the air conditioning units on both sides of the east and west sides can not meet the design requirements under the condition that the air valves of the end equipment are all open. Therefore, it is suggested that the valve opening of the terminal equipment in the large air supply area should be reduced when the air conditioning system is in operation, so as to ensure the uniformity of the air supply volume of the air supply outlets. The results of this paper are of great significance to the optimization of air conditioning system scheme and to the design of other similar large buildings.
【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】：TU83

【参考文献】