General Energy Consumption Evaluation Methods Of Large Coal-fired Power Generation Units

China's energy structure is dominated by coal utilization,and coal-fired power generation is the most important way of coal utilization.In China,the healthy and sustainable development of coal-fired power generation directly affects China's energy security and clean energy utilization.With the continuous upgrading of coal-fired power generation technology and the phasing out of backward production capacity,ultra-low emission technology has been vigorously promoted and developed.The high efficiency,cleanliness and low carbonization of energy utilization are the trend of energy development in the world,meanwhile,the continuous maturity and comlercial application of new energy technologies have further squeezed the living space of traditional coal-fired power stations.At present,the energy consumption level of coal-fired power generation in China is already in the forefront of the world,and its emission level has also reached the gas turbine emission standard.In the short term,the space for further energy conservation and emission reduction based on existing technologies has been very limited.In this situation,how to dig deep into its potential for energy conservation and consumption reduction,maintain its competitiveness with new energy power generation technology,and enhance its ability to serve the quality of China's energy system has become an urgent issue.This topic breaks through the traditional concept of energy consumption evaluation of unit heat system,and proposes that the unit system and the related constraint environment form a generalized energy system,which is used to conduct a generalized energy consumption evaluation research.This paper takes the comprehensive characteristics of generalized energy system as the starting point,and uses multi-objective evaluation technology as the main method.Therefore,in this paper,the classical energy system evaluation method is deeply researched and expanded,whose ability to analyze the energy consumption indicators of the unit system under the actual boundary conditions is improved.On this basis,the applicability of multi-objective evaluation technology in the general energy consumption evaluation of coal-fired generating units is explored.The specific key problems are analyzed and corresponding measures and improvement directions are proposed.The evaluation of the characteristics of generalized energy systems is conducive to comprehensively grasping its system characteristics,standing at a higher angle,correctly guiding the direction of energy conservation and emission reduction work,and providing valuable reference for the formulation and decision-making of relevant policies.First of all,the theoretical basis of this paper is deeply studied,and the equivalent relationship between the specific product consumption and the coal consumption of power generation is demonstrated.Also,this paper clarifies the difference between the theoretical distribution and the energy consumption distribution which is in the case that the low calorific value of coal combustion approximates its specific exergy,and figures out the fact that the bias is classified into the boiler combustion process.Meanwhile the quantitative calculation method of the bias is given in this paper.It demonstrates the rationality and convenience of this approximation calculation for engineering applications under normal circumstances.At the same time,the quantitative analysis of the influence of the reference ambient temperature on the spcecific consumption analysis is carried out,which confirms the importance of clarifying the reference environment when the spcecific consumption analysis method is implemented.With the change of the reference ambient temperature,the condenser and the energy consumption of the boiler exhaust process is sensitive.In addition,for the shortcomings of the spcecific consumption analysis method in dealing with the actual redundant data of the unit,the data coordination method is introduced into the modeling process of spcecific consumption analysis.The improved data coordination method considers the space redundancy measurement and quasi-steady state of the unit system.The redundant information in the time series has a higher reliability,and the energy consumption index obtained by implementing the spcecific consumption analysis is more realistic.Secondly,the applicability of multi-objective evaluation technology in the general energy consumption evaluation of coal-fired generating units is analyzed.The generalized process and related elements of multi-objective evaluation technology are systematically studied,and the factors that easily affect the evaluation results are analyzed.Also,the direction in which the model can be adjusted is figured out.The common problems of multi-objective evaluation techniques are summarized.The effects of small sample processing techniques,evaluation index correlation problems,sensitivity analysis of weights,and uncertainty analysis of weights and misclassification of indicators in multi-level evaluation models are discussed in detail.And the processing methods for solving the problems above,including the introduction of Bootstrap method in small samples,quantitative calculation of AHP weight uncertainty,and multi-level evaluation technical indicators location sensitivity calculation methods,are given in the paper.Finally,combined with the actual application situation,the evaluation of the coal-fired generating units based on the characteristics of the unit was carried out.A unit ranking evaluation model for future energy-saving power generation dispatching and an evaluation model for the sustainability of coal-fired generating units are established.The model is mainly based on the grey relational evaluation model.The information entropy model,AHP method,fuzzy rough set method and game combination model are comprehensively used.At the same time,the sensitivity analysis and uncertainty analysis of the index are carried out.Through the mining and utilization of sample information,it aims to increase the transparency of the evaluation model from the technical level,improve the credibility of the evaluation results,reduce the application difficulty of the unit comprehensive evaluation technology,and provide meaningful guidance for correct decision-making.This paper starts with theoretical analysis and combines the practical application requirements to explore the applicability of multi-objective evaluation technology in the general energy consumption evaluation of coal-fired generating units.The system's evaluation process and method system are initially established,which can be similar to generalized energy systems.Target evaluation work provides meaningful reference and guidance.