基于降耗时空效应的大型火电机组节能诊断方法

发布时间：2018-01-25 06:02

本文关键词： 大型燃煤发电机组节能诊断能耗基准状态降耗时空效应 (火用)分析　出处：《华北电力大学(北京)》2017年博士论文　论文类型：学位论文

【摘要】：能源,尤其是电力,是国家经济的基础和命脉。我国燃煤发电长久以来占据总发电量的百分之七十以上,目前已确立了超(超)临界高参数大容量机组的未来火电主力地位,其能耗水平已经达到世界一流水平。然而,随着化石能源的消耗加剧与环保要求的日益严格,我国对大型燃煤发电机组的深度节能的需求日益迫切,“十三五”电力规划已对我国火电发电行业的煤耗与污染物排放提出了新的要求。在此背景下,针对大型燃煤发电机组的节能诊断研究必将在火电产业的节能降耗中起到至关重要的作用。本研究着眼于大型燃煤发电机组,进一步发展了能量系统过程节能分析方法。综合考虑机组能耗在时空维度上的变化特性,提出了大型燃煤机组降耗时空效应的概念。在此基础上,开展了一系列大型燃煤发电机组节能诊断方法的研究。全面揭示了机组部件性能发生衰退时系统能耗的耦合机理;详细分析了火电机组运行时能耗在各部件之间的耦合规律,以及能耗与多变边界条件的依变关系;研究能耗分析理论方法,表征和确定超低排放能耗基准状态,得到机组降耗时空效应,并在此基础上,开展节能诊断方法与负荷优化分配应用,为大型燃煤机组的评价、改造和优化提供了可靠的方法论和实施手段。首先,应用先进(火用)分析的思想方法,改进了基于热力学第二定律的单耗分析方法,将部件的附加单耗分解为内因附加单耗和外因附加单耗。其中,前者是由部件自身的不可逆性引起的,而后者是由其它部件的热力学缺陷造成的。改进后的单耗分析方法能够描述燃煤机组的空间能耗水平。在此基础上,结合大型燃煤发电机组在不同时间所处的复杂多变边界条件,提出了降耗时空效应概念,量化计算和评价燃煤发电机组的能耗水平,作为进一步节能诊断工作的依据。其次,根据降耗时空效应的概念,结合能量系统节能诊断方法,进行了三方面的研究应用:(1)提出了基于改进单耗分析的燃煤机组部件性能诊断方法,采用一种新型的内部(火用)指标快速定位故障部件,随后对比实际状态与参考状态的内因附加单耗差异,以量化部件故障的影响,可有效地侦测部件的性能衰退状况,为可能的部件故障预警提供理论依据;(2)在大型燃煤发电机组部件性能诊断的基础上,考虑到大型火电机组在运行过程中会面临复杂多变的边界环境,本文使用多维度、完备性的运行与结构数据,提出了综合考虑火电机组时空因素的“能耗基准状态”,并计算分析相应的降耗时空效应进行机组流程重构分析,提出可行的火电机组节能措施;(3)针对大型燃煤发电机组运行过程中所处的复杂边界条件,详细分析了边界条件(负荷、冷却水温度和煤质因素)的特点,以及边界条件与火电机组间的传热机理,并探索了能耗基准状态与边界环境的变化规律。最后,基于降耗时空效应对大型燃煤发电机组进行节能诊断,将诊断结果分别应用于考虑边界条件和污染物排放的燃煤电厂厂级负荷优化分配问题中。基于火电机组的海量运行数据,引入大数据分析方法,获得机组不同边界和运行工况下的能耗特性;另外,综合考虑经济和排放因素,建立基于物理信息融合的负荷分配模型,得到机组煤耗和污染物排放量物理模型与信息模型的对应关系;以此为基础开展的厂级负荷优化分配可有效降低火电厂的供电煤耗率,对火电机组的节能发电调度具有参考意义。结合实际设计的更多约束,所形成的方法论有潜力切实地服务于大型燃煤发电机组的运行诊断、设计优化或改造,以提出具体可行的运行策略和改进方案。
[Abstract]:Energy, especially electricity, is the foundation and the lifeblood of the national economy. China's coal-fired power generation long since occupy the total generating capacity of more than seventy percent, has established the ultra (ultra) critical high parameter and large capacity units in the future the main power status, its energy consumption level has reached world-class level. However, with the increasing consumption and environmental protection the fossil energy requirements increasingly strict, the depth of China's energy-saving of large coal-fired power units has become increasingly urgent, "13th Five-Year" has been on the electric power planning and thermal power generation industry in China's coal consumption and pollutant emission, put forward new demands. Under this background, the study will energy-saving diagnosis of large coal-fired power plant is very important to the effect of energy saving in thermal power industry in China. This study focuses on the large coal-fired power units, the further development of the analysis method of energy system energy saving in the process of integrated test. Consider the unit energy consumption change characteristics in the temporal dimension, and put forward the concept of space-time effect of the large coal-fired units. On this basis, to carry out a series of studies in large coal-fired power plant energy saving diagnostic method. Reveal the coupling mechanism of the energy consumption of the system components of units performance decline; a detailed analysis of the thermal power unit energy consumption coupling the law between the parts, and the relationship between energy consumption and in accordance with the changeful boundary conditions; analysis theory and method of energy consumption, and to determine the characterization of ultra low emission energy consumption benchmark, unit consumption by spatio-temporal effect, and on this basis, to carry out energy-saving diagnosis method and application for the evaluation of optimal load distribution, large coal-fired units, provide a reliable methodology and means of implementing the transformation and optimization. Firstly, the application of advanced (exergy) analysis method, improved based on the second law of thermodynamics The unit consumption analysis method, the additional consumption components into internal and external additional consumption of additional consumption. Among them, the former is caused by the irreversible component of its own, which is caused by defects in other parts of the thermodynamics. The space consumption of energy consumption level improved analysis method can describe the coal unit. On the basis of and with the large coal-fired power units are located in different time with complex boundary conditions, put forward the concept of time-space effect consumption, quantitative calculation and evaluation of energy consumption of coal-fired generating units, such as further diagnostic work basis. Secondly, according to the concept of saving space and time effect, combined with energy-saving diagnosis method of energy system, the research and application in three aspects: (1) proposed coal-fired unit components performance diagnosis method based on the analysis of consumption, with a new type of internal (exergy) index rapid positioning The fault component, then cause additional consumption differences between the actual state and the reference state, in order to quantify the influence of component failure, can effectively detect the performance of parts of the recession, and provide a theoretical basis for early warning of possible fault components; (2) on the basis of performance diagnosis in large coal-fired power plant parts, taking into account the large thermal power unit will face the complicated boundary environment during operation, this paper use the multi dimension, operation and structure data completeness, the comprehensive consideration of thermal power units in spatial and temporal factors "energy consumption benchmark", and calculation analysis unit flow reconstruction analysis of space-time effect of the corresponding consumption, put forward feasible energy saving measures of thermal power units (3;) for the complicated boundary conditions at large coal-fired power generating units in operation, a detailed analysis of the boundary conditions (load, cooling water temperature and coal quality characteristics, and factors) The mechanism of heat transfer boundary conditions and thermal power units, and to explore the changes of energy consumption benchmark and boundary environment. Finally, the energy-saving diagnosis of large coal-fired generating units of consumption based on time-space effect, the diagnosis results are applied to consider the boundary conditions and the discharge of pollutants from coal-fired power plant optimal load distribution problem in the massive operation data. Thermal power unit based on the introduction of big data analysis method, obtain the energy consumption characteristics of different boundary and under the operating conditions; in addition, considering the economic and emission factors, establish the physical load distribution model based on information fusion, get the corresponding relationship between coal consumption and pollutant emissions of physical model and information model based on the plant; load distribution optimization can effectively reduce the coal consumption rate of thermal power plant, has the reference significance of energy-saving power generation dispatching on power plant. Combined with more constraints of practical design, the methodology formed has potential and practically serves the operation diagnosis, design optimization or transformation of large coal-fired generating units, so as to put forward specific and feasible operation strategies and improvement plans.

【学位授予单位】：华北电力大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM621

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