直接空冷机组冷端系统能效评价与故障诊断方法研究

发布时间：2018-04-03 13:07

本文选题：冷端系统　切入点：能效评价　出处：《华北电力大学》2015年硕士论文

【摘要】：直接空冷机组在我国富煤贫水地区得到了快速的发展。本文针对直接空冷机组,建立了能效评价模型,实现了冷端系统能效实时评价。对评价结果不理想的情况分别按评价等级进行运行可调类参数优化或冷端系统可维护类故障诊断,以提高冷端系统的能效水平,提高直接空冷机组的热经济性和安全性。能效评价模型运用了AHP-F评价方法展开评价。能效评价的等级分别是优秀、良好、一般、需改进、需整顿。当冷端系统性能评价结果为需改进时,冷端系统需要优化调整。优化的目标值是最佳背压,本文建立了冷端系统变工况数学模型,结合直接空冷电厂背压功率修正曲线和风机群耗功与背压的关系曲线,得出了变工况条件下确定最佳背压及最佳风速的办法,以最佳背压为基准值进行计算,可以得出冷端系统优化后的节能空间。当冷端系统的评价结果为需整顿时,冷端系统的可维护类故障诊断任务被触发。冷端系统性能下降的故障顶事件是真空下降,可能是由风机系统故障、轴封系统故障、抽真空系统故障、主凝结水系统故障、空冷凝汽器设备的其他故障引起的。本文针对13个故障,结合FTA分析方法,进行了故障模式分析、故障征兆分析、故障原因分析、故障影响分析和故障维修措施分析,建立了十分完备的冷端系统知识库。在此基础上,应用模糊模式识别进行冷端系统的故障诊断,研究表明,糊模式识别诊断方法的诊断准确性高、分离效果明显。
[Abstract]:Direct air-cooled units have been developed rapidly in coal-rich and water-poor areas in China.In this paper, the energy efficiency evaluation model is established for direct air cooling unit, and the real time energy efficiency evaluation of cold end system is realized.In order to improve the energy efficiency level of the cold end system and improve the thermal economy and safety of the direct air cooling unit, the optimal operation parameters of the cold end system or the fault diagnosis of the maintainable type of the cold end system are carried out according to the evaluation grade.The energy efficiency evaluation model uses the AHP-F evaluation method to carry out the evaluation.The rating of energy efficiency evaluation is excellent, good, general, need to be improved, need to be rectified.When the performance evaluation of the cold end system needs to be improved, the cold end system needs to be optimized and adjusted.The optimum target value is the optimum backpressure. In this paper, a mathematical model of the cold end system under variable working conditions is established, combining with the power correction curve of backpressure in direct air-cooled power plant and the relation curve between fan group power consumption and backpressure.The method of determining the best back pressure and the best wind speed under the condition of variable working condition is obtained. The energy saving space after the optimization of the cold end system can be obtained by using the best back pressure as the reference value.When the evaluation result of the cold end system is rectified, the maintainable fault diagnosis task of the cold end system is triggered.The failure top event of the performance decline of cold end system is vacuum drop, which may be caused by fan system fault, shaft seal system fault, vacuum pumping system fault, main condensate system fault, other faults of air-cooled condenser equipment.In this paper, according to 13 faults, combined with FTA analysis method, fault mode analysis, fault symptom analysis, fault cause analysis, fault impact analysis and fault maintenance analysis are carried out, and a very complete knowledge base of cold end system is established.On this basis, the fault diagnosis of cold end system is carried out by using fuzzy pattern recognition. The research shows that the diagnosis method of paste pattern recognition has high diagnostic accuracy and obvious separation effect.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM621

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