空调水系统变频控制对冷水机组COP影响及综合能耗研究

发布时间：2018-08-13 11:25

【摘要】：中央空调水系统变频控制技术是空调节能技术之一，其在实际工程中的应用日益广泛，但该技术的应用会对冷水机组的性能产生影响，，而目前很多既有中央空调水系统的变频节能技术改造工程往往忽视改造后水系统变流量运行时冷水机组性能的变化。为此，本文以深圳某商场中央空调水系统为例，通过理论分析结合模拟分析和实验测试，探讨研究空调水系统变流量运行时冷水机组COP及机房侧综合能效COPz的变化。本文首先对冷冻水变流量和冷却水变流量时冷水机组性能的变化机理作了理论分析，分析结果表明：冷冻水变流量对冷水机组性能影响较小，而冷却水变流量则对冷水机组性能影响较大。其次，建立了离心式冷水机组性能计算模型，以此为基础，对部分负荷状态下的给定机组卸载率和控制蒸发器出水温度这两种运行工况进行模拟，并利用设备生产厂家测试数据验证了计算模型的准确性。接着，结合实际工程案例对中央空调水系统变流量进行了实验研究，分别针对不同的变流量模式做了运行测试，利用测试数据对各运行工况下冷水机组的COP值进行了计算分析，得出机组COP值随相应参变量的变化规律，给出模拟结果及与实验数据的对比分析，并分别从单变冷冻水流量、单变冷却水流量及同时变冷冻水冷却水流量三个方面进行了数据分析。最后，建立了中央空调水系统机房侧设备的总能耗计算模型,并结合冷水机组性能计算模型对机房侧综合能效COPz进行了模拟计算，且与由测试数据计算得出的COPz值进行了对比，从而得出了空调水系统变流量运行各典型工况下COPz值的变化规律。
[Abstract]:The frequency conversion control technology of central air conditioning water system is one of the air conditioning energy saving technologies, and its application in practical engineering is increasingly widespread, but the application of this technology will have an impact on the performance of chillers. At present, many existing central air conditioning water system conversion and energy saving technology renovation projects often ignore the change of the performance of chillers when the water system is running at variable flow rate after the revamping. Therefore, taking the central air conditioning water system of a shopping mall in Shenzhen as an example, through theoretical analysis, simulation analysis and experimental test, the changes of COP of chillers and comprehensive energy efficiency COPz on the side of the machine room are studied when the air conditioning water system is running at variable flow rate. In this paper, the mechanism of performance change of chillers with variable chilled water flow rate and cooling water variable flow rate is analyzed theoretically. The results show that the influence of chilled water variable flow rate on the performance of chillers is small. However, the variable flow rate of cooling water has a great influence on the performance of chillers. Secondly, the performance calculation model of centrifugal chillers is established. Based on this model, two operating conditions, namely, the given unit unloading rate under partial load and the control of evaporator outlet temperature, are simulated. The accuracy of the calculation model is verified by the testing data of the equipment manufacturer. Then, combined with practical engineering cases, the variable flow rate of central air conditioning water system is studied experimentally, and running tests are made for different variable flow modes, and the COP values of chillers under different operating conditions are calculated and analyzed by using test data. The variation law of unit COP value with the corresponding parameter variables is obtained. The simulation results and the comparison with experimental data are given, and the flow rate of single variable refrigerated water is analyzed respectively. The data were analyzed from three aspects: single variable cooling water flow rate and simultaneous cooling water flow rate. Finally, the total energy consumption calculation model of the central air conditioning water system is established, and the comprehensive energy efficiency COPz of the central air conditioning water system is simulated with the performance calculation model of the cooling water unit. Compared with the COPz value calculated from the test data, the variation law of COPz value under various typical operating conditions of air conditioning water system with variable flow is obtained.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU831

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