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针对正常运行的冷水机组故障难以预测的问题,提出了关联规则挖掘的故障诊断方法,通过读取冷水机组历史数据库,挖掘出各个变量与故障之间的关系。由于Apriori算法可能因人工设置的支持度不合理导致关联规则挖掘结果不能满足需求,故提出了采用改进Apriori算法实现冷水机组故障关联规则挖掘。实验结果表明,改进后的算法在准确率、扫描数据库次数以及运行时间上有明显改善。 相似文献
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本文针对冷水机组能耗模型参数辨识过程及冷水机组的渐变性及突变性,提出了冷水机组能耗模型参数的自适应在线辨识方法。首先,根据冷水机组能耗模型参数的变化情况建立了冷水机组的遗忘因子自适应模型,介绍了冷水机组能耗模型的递推最小二乘格式。而后,以某酒店离心式冷水机组为例对冷水机组能耗模型参数的辨识方法进行了实例分析。结果表明,变遗忘因子的自适应在线辨识方法在辨识过程中能够适应冷水机组能耗模型时变性的需求,提高了冷水机组能耗模型在系统渐变和突变过程中的辨识精度,为进一步的冷水机组在线运行优化控制及故障诊断提供了参考。 相似文献
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水冷式冷水机组选型分析 总被引:3,自引:0,他引:3
水冷式离心、螺杆和活塞式冷水机组以其各自鲜明的特点,优良的性能而在大、中和小冷量范围内得到广泛的应用。本文分别对水冷式离心、螺杆和活塞冷水机组所使用不同制冷剂、不同工况和不同污垢系数进行了理论分析和实际性能对比,给出其对水冷离心式、螺杆式和活塞式冷水机组性能影响的大小,为实际选型和使用打下基础。 相似文献
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对当前空调用冷水机组的综合分析 总被引:6,自引:1,他引:5
本文归纳了CFCs替代物情况,分析了当前各种型式冷水机组性能特点,制冷能耗及其直接和间接全球暖化(温室效应)问题,并对冷水机组的合理选用结合实际举例作了综合技术经济比较,得出了几点结论。 相似文献
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Ageing inevitably leads to capacity degradation in a chiller plant. Hence in the life-cycle performance analysis of a chiller plant, ageing always represents a crucial consideration for designers. Ageing is normally quantified using maintenance factor. A conventional analysis recommends that the maintenance factor should be 0.01 for systems that undergo annual professional maintenance, and 0.02 for those that are seldom maintained. However, this recommendation is mainly based on a rule of thumb, and may not be accurate enough to describe the ageing for a given chiller plant. This research therefore proposes a method of identifying the chiller maintenance factor using a Bayesian Markov Chain Monte Carlo method, which can take account of the uncertainties that exist in the estimation of the ageing. Details of the identification will be provided by applying the proposed method to a real chiller plant, and results will be compared with that of the conventional analysis. 相似文献
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冷水机利用变流量冷冻水的若干设计问题 总被引:8,自引:4,他引:8
目前变水量冷冻水系统的设计一般都采用一、二次双环路方式。但这种双环路配置方式会产生:使用两个水泵增加设备投资;冷冻水送水及回水的混合影响冷水机在部分负荷时的效率;实际的高负荷空调需求条件与最大设计工况条件不吻合时不能充分利用冷水机的全负荷容量等不良后果。设计单环路空调冷冻水系统可以避免上述问题。讨论了单环路变流量系统的长处以及可能产生的问题,并提供在整个运行范围内,能够实现安全、稳定和可靠的冷水机控制策略。 相似文献
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离心式制冷机系统传感器故障诊断的试验研究 总被引:2,自引:0,他引:2
传感器的可靠性及准确性对制冷机系统的可靠控制和系统的最优运行起着至关重要的作用。同时,传感器的读数也是进行部件故障诊断的基础。本文提出了基于主元分析法的制冷机传感器故障诊断方法,该方法的主元分析模型由离心式制冷机系统中的相关测量变量在正常条件下的观测样本构成。这一方法利用这些变量在正常条件下的相关性来对传感器的测量观测值进行故障检测与诊断及测量重构,并分别用Q-统计及Q-分布图来对传感器故障进行检测及诊断。本文利用实验室离心式制冷机的试验数据对这一基于主元分析法的传感器故障诊断方法进行了验证。 相似文献
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Air-cooled chillers are widely used to provide cooling energy for air-conditioned buildings at the expense of considerable electricity. The (Air-Conditioning & Refrigeration Institute) ARI standard 550/590 sets out a rating condition to specify the coefficient of performance (COP) of the chillers under part-load conditions. This condition was found to be insufficient to deal with diverse operating conditions under the multiple chiller arrangement. This paper proposes an alternative approach to specifying more precisely the chiller COP under part-load conditions. It is desirable to establish a set of part-load performance curves showing how the chiller COP varies with the condensing temperature at various combinations of chiller loads and outdoor temperatures. The results of this paper will give engineers and researchers a better idea about how to specify the upper limit of condensing temperature for more energy efficient chillers and how chiller COP curves help compare air-cooled chillers for buildings in any climate zone and to estimate the annual electricity consumption of chillers satisfying any given building cooling load profile. 相似文献
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《Building and Environment》2005,40(6):727-737
Air-cooled chillers are commonly used to provide cooling energy in commercial buildings in the subtropical climate. These chillers have long been considered inefficient because they operate under head pressure control where the condensing temperature is kept high in the refrigeration cycle. This paper considers a novel method to strategically lower the condensing temperature to enhance chiller efficiency at any outdoor temperature. An experiment is carried out on an air-cooled reciprocating chiller to confirm that an electronic expansion valve enables refrigerant to be adequately fed into the evaporator in all operating conditions, even when the condensing temperature falls to around 20 °C. By enhancing the heat rejection airflow of the condenser, both the condensing temperature and chiller power can decrease considerably with less fluctuation. According to the algorithm of staging condenser fans, this enhancement corresponds to resetting the set point of the condensing temperature based on any outdoor temperature. The potential and benefits of implementing this reset strategy are discussed. 相似文献