空调冷冻水系统用户侧整体模型研究

发布时间：2018-03-01 04:40

本文关键词： 空调系统冷冻站及冷冻水系统用户侧整体模型模拟计算设计应用　出处：《清华大学》2013年硕士论文　论文类型：学位论文

【摘要】：空调冷冻站及冷冻水系统是空调系统的重要组成部分，其设计水平和实际运行管理会直接影响空调系统的能耗。通过大量的文献调研和实地测试，发现在空调冷冻水系统的运行和设计中存在着许多问题，如实际运行中冷冻水系统的“大流量小温差”现象、冷冻水系统形式的选择等。由于空调冷冻站及冷冻水系统的复杂性，影响因素众多，在分析设计方案时，需要我们对全年工况进行计算分析，这就需要既能反映实际现象又计算功能完备的模拟软件。目前较常用的能耗模拟软件虽然具有空调冷冻站全年能耗模拟计算的功能，但无法反映冷冻水系统的实际运行特性，，其关键问题是这些软件缺少反映用户侧水系统整体性能的模型。用户侧水系统的整体特性决定了冷冻站的运行性能，但目前关于用户侧整体特性的研究成果较少，因此，本论文的主要研究目标是通过实际运行数据与模拟结果的比较，建立合理的用户侧整体模型，从而实现冷冻站和用户侧的联合模拟计算，以辅助解决设计阶段的实际问题。首先，本文从单个盘管的实际运行数据与换热模型出发，分析单个盘管的动态控制特性，并确定影响换热性能的关键因素。其次，根据盘管水阀控制的不同特点，本文分别针对连续控制盘管和通断控制盘管的水系统整体特性，进行了实际数据与模拟计算结果的对比，归纳其关键性影响因素，最终分别建立了两者的用户侧整体模型。然后，结合用户侧水系统的整体模型和冷站计算模型，建立了冷冻站及冷冻水系统的联合模拟计算方法，并在程序中实现。最后，本文对两种空调末端形式的冷冻水系统进行了不同工况下的模拟计算，包括一级泵变频控制运行工况和过渡季提高冷机出水温度的节能效果。本文为冷冻站及冷冻水系统的设计提供了一种全工况的模拟计算方法，可以为实际设计问题提供帮助，如冷冻水系统形式的选择、供水温度设计、压差控制等，也可以通过对各种技术手段的全工况模拟，来比较分析技术手段的运行性能和能耗水平。本文的工作使得我们更加理解用户侧冷冻水系统的整体特性，并提供有效的整体模型用于冷冻站的模拟计算，为解决设计阶段的实际问题提供帮助。
[Abstract]:Air conditioning refrigeration station and chilled water system are important parts of air conditioning system. Its design level and actual operation management will directly affect the energy consumption of air conditioning system. It is found that there are many problems in the operation and design of air conditioning chilled water system, such as the phenomenon of "large flow and small temperature difference" in the actual operation of the chilled water system. Because of the complexity of the air conditioning refrigeration station and the chilled water system, there are many influencing factors. When we analyze the design scheme, we need to calculate and analyze the whole year's working conditions. This requires a simulation software that can reflect both the actual phenomenon and the complete calculation function. Although the energy consumption simulation software which is commonly used at present has the function of simulating and calculating the annual energy consumption of the air conditioning refrigeration station, it cannot reflect the actual operation characteristics of the refrigerated water system. The key problem is that these software lack models that reflect the overall performance of the user-side water system. The overall characteristics of the user-side water system determine the operation performance of the refrigeration station, but there are few research results on the overall characteristics of the user-side water system. The main research goal of this paper is to establish a reasonable overall model of the user side by comparing the actual operation data with the results of simulation so as to realize the joint simulation calculation between the freezing station and the user side in order to help solve the practical problems in the design phase. Firstly, based on the actual operation data and heat transfer model of a single coil, the dynamic control characteristics of a single coil are analyzed, and the key factors affecting the heat transfer performance are determined. Secondly, according to the different characteristics of the control of the coil water valve, In this paper, according to the whole characteristics of the water system of the continuous control coil and the on-off control coil, the comparison between the actual data and the simulation results is carried out, and the key influencing factors are summarized. Finally, the user side integral model of the two systems is established respectively. Then, combined with the whole model of the user side water system and the cold station calculation model, the combined simulation calculation method of the refrigeration station and the refrigerated water system is established and realized in the program. Finally, In this paper, two kinds of air conditioning end forms of chilled water system are simulated under different working conditions. This paper provides a simulation calculation method for the design of refrigerating station and chilled water system, which can be helpful to the practical design, including the operation condition of frequency conversion control of the first stage pump and the energy saving effect of increasing the outlet temperature of the cooler during the transition period, this paper provides a simulation calculation method for the design of the refrigeration station and the chilled water system. For example, the selection of refrigerated water system form, the design of water supply temperature, the control of pressure difference and so on, can also compare and analyze the operation performance and energy consumption level of technical means by simulating the whole operating condition of various technical means. The work of this paper makes us better understand the overall characteristics of the user-side chilled water system, and provide an effective global model for the simulation calculation of the refrigeration station, which can help to solve the practical problems in the design phase.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU831

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