【作者】 李志生；

【导师】 张国强；

【作者基本信息】 湖南大学 ， 供热、供燃气、通风及空调工程， 2008， 博士

【摘要】 HVAC&R系统的能耗在国民经济中的能耗占了相当大的比重,特别是服务于公共建筑的大型制冷机组,是现代建筑的主要能耗终端。制冷机组存在故障时,会造成制冷机组的性能下降,同时将降低建筑用户的舒适性水平。因此,对商业使用的大型水冷式制冷机组进行故障检测与诊断,并使制冷机组优化运行、控制于正常工作状态具有重要的意义。本文的目标就是开发一种稳健的、基于物理定律的制冷机组故障检测与诊断方法,从而使复杂的制冷系统不需要增加新的传感器而使用机组本身的传感器就可以进行故障检测与故障诊断。本文首先对大型水冷式制冷机组的故障情况进行了调查,通过多种方法,对制冷各部件、各组件的故障进行了详细的调研,并使用统计学原理,对制冷机组各部件的故障率、使用寿命等进行了分析,得到了各故障的分布规律。其次,通过对制冷机组工作过程的合理简化,在热力学第一、第二定律等物理定律的基础上,采用特征参数与故障因子的方法,概括、提取了制冷机组发生故障时的参数特征,建立了大型蒸汽压缩式制冷机组故障检测与诊断的静态模型。为使建立的模型能够检测和诊断制冷机组实际运行过程中所发生的故障,对所采集的动态数据进行了处理。为检验制冷机组故障检测与诊断模型的正确性和有效性,运用所建立的数学模型,开发了制冷机组故障检测与诊断工具,对制冷机组故障检测工具进行了总体设计和软件编程,并对这个模型进行了校验。运用所建立的模型和诊断工具,对来自于现场的实验数据进行了分析。以HXC165A制冷机组为例,分析了各种故障条件下的性能变化,通过对比故障条件和健康条件下各特性参数的变化规律,得到了各种故障的报警条件和极限停机条件。因此,故障检测与诊断过程中所进行的参数监控也对优化制冷机组的运行具有重要的意义。最后,运用可靠性理论,对制冷机组的可靠性指标进行了计算,对故障修复进行了分析,重点对故障检测与诊断的经济性进行了分析,从而证明了制冷机组故障检测与诊断的巨大意义,使本文的逻辑性、连贯性得到了更好的体现。更多还原

【Abstract】 The energy consumption of heating,ventilation,air-conditioning and refrigerating(HVAC&R)systems plays a significant role in national economy. Especially,the large-scale chiller plants,which serve for modern public buildings, are the chief energy consumption terminals.When the chiller plants are existence of faults,it will decline the coefficient of performance(COP),and also the comfort levels for building occupants.Therefore,it is essential for large-scale business operated water-cooling chiller plants to carry out fault detection and diagnosis(FDD) and make them optimization conditions.The objective of this research work is to develop a robust physical law model-based FDD methodology for chiller plants. Consequently,the complicated refrigeration system can carry out FDD as much as possible on using existing sensors,tranducers and other hardware rather than requiring those installed specially for this purpose.The faults survey for large-scale water-cooling chiller plants are obtained at first in the paper.The fault occurrence of chiller plants components are surveyed through fully field investigation,and then the faults rates and lifetimes are analyzed with statistical theory,therefore,the faults distribution rules are acquired.Secondly,based on the thermodynamic first and second laws,the faults characteristic parameters(CQs)and faults indexs(FIs)are generalized and drawn by reasonable simplification chiller plants operation process.Therefore,the static state FDD models are established for the large-scale evapor compressed chiller plants combination the CQs and FIs.The practical dynamic operation data are pretreated so as the established static state models can detect and diagnose the chiller plants faults during the real operation conditions.Thirdly,the FDD tool has been developed with modeled mathematic models in order to verify the preciseness and validity of the chiller plants.The FDD tool has been programed and verified with established models.The field experiment data with large-scale chiller plants are utilized to analyze FDD tool.The performance diversifications under different fault conditions are analyzed with HXC165A as example.By comparison the rules of characteristic parameters under the fault and fault-free conditions,the threshold value of alarm and termination conditions have been obtained as well.Therefore,the parameters monitoring during the FDD is also significant for the chiller plants performance optimization. Lastly,the faults modification and reliability indexes are discussed and analyzed with reliability theory.Especially,the economic effect during the FDD for chiller plants are analyzed as well,which argues the grand meaning of FDD,and also bring the paper better logicality and continuity.更多还原