Research On Energy Efficiency Evaluation Of Subcritical Steam Drum Boiler In Thermal Power Plant

As one of the three main engines of thermal power plant,the boiler is a major energy consumer and it is the focus of national energy conservation and consumption reduction work.It is an important basis for improving energy efficiency to do well in condition monitoring and evaluation of power plant boiler equipment.The higher the utilization rate of energy in the work of boiler equipment,the better the running state of the boiler,therefore,the operation status of boiler equipment can be monitored by monitoring efficiency.This paper establishes an energy efficiency evaluation model to evaluate the energy efficiency of the boiler,and establishes a calculation model of the boiler efficiency to analyze the state of the boiler equipment.In this paper,the fuzzy comprehensive evaluation method is used to model the boiler energy efficiency evaluation.In building the evaluation index system of boiler energy efficiency,starting from the structure and energy balance of the boiler,the thermal efficiency of each heat exchange surface in the boiler and the heat loss of the boiler are selected as the energy index of boiler energy efficiency,and considering the energy efficiency of the boiler from the energy utilization of the boiler and the impact of the emission of flue gas on the environment,the boiler energy efficiency evaluation index is selected.In view of the unreasonable problem of determining the weights of current evaluation indicators,this paper adopts different methods to determine the weights of different indicators according to the categories of indicators.Expert consultation method is adopted to determine the weights of the first-level indicators.For the secondary indicators under the energy index,the method of combining the analytic hierarchy process with the entropy weight method is adopted to determine the weight.and for the secondary indicators under the environmental indicators,the weights are determined according to their harmful degree to the environment.Establish a boiler energy efficiency calculation model to calculate boiler evaluation indicators.In this paper,the input and output heat and various heat losses of utility boilers are analyzed,and the efficiency of boilers is calculated respectively from the two aspects of positive and negative balance of energy.The average value of positive and negative balance efficiency is taken as the final boiler efficiency to make the calculation of boiler efficiency more reasonable.To analyze the energy utilization inside the boiler,according to the operating principle of the power station boiler,In this paper divided the main heat transfer parts of the boiler into super-heater,re-heater,economizer and air pre-heater,and analyzed the output heat and input heat of each heat exchange part of the boiler,and the calculation algorithm of the thermal efficiency of each heat exchange part of the boiler is established to monitor the operation state of the boiler equipment.After programmed with MATLAB language,this algorithm can calculate the real-time thermal efficiency of each part of the power plant boiler equipment and draw its curve,which is expected to help the technicians to monitor the operation status of the power station boiler equipment.This paper takes a 330 MW coal-fired power station boiler as the research object,and uses the model built in this paper to calculate and analyze its operating state,and evaluate the energy efficiency.The results show that the overall energy efficiency of the boiler is good,and the energy efficiency of the re-heater and the economizer needs to be improved,which is consistent with the actual situation,which shows that the model is feasible and accurate,and can analyze the energy efficiency of the boiler well.Find the weak link of boiler energy efficiency utilization,which is conducive to the optimal operation of the boiler.