Study On Flue Gas System Optimization And Energy Saving Operation Of A 350MW Unit

Improving the economy of the flue exhaust system at the tail of the unit is one of the main ways to save energy and reduce consumption of thermal power plant A power plant in 2014 and 2015 to carry out a dual-unit share a smoke exhaust tower technical transformation of its 350 MW # 2 units due to space constraints and the transformation of the urgent time constraints,ESP outlet to draft fan inlet section flue there are more Of the elbow and shaped pieces,resulting in a large total loss of the rear flue and affect the operation of the unit economy;and share a tower of the double unit configured induced draft fan due to different types and have different power consumption When the total load is constant,there is a problem that the total power consumption of the induced draft fan is high due to the unreasonable load distribution of the unit.Aiming at the problem that the total pressure loss of flue gas from outlet of electrostatic precipitator in the second unit to induced draft fan is too large,combined with experimental data,numerical simulation software Fluent is used to simulate the flue in this section by using standard k-? model.The results show that the main part of the average total pressure loss in this section is from the joint header and elbow.In order to reduce the loss and consider the cost of reconstruction,the concept of three-dimensional flue design based on two-dimensional feature plane was established.The drag reducing effect of three sets of flue reformation schemes was proposed and simulated progressively.The results showed that the three-The average total pressure loss of section flue decreases from 966 Pa of original flue to 176 Pa,and the drag reduction rate reaches 81.7%,which is the optimal solution.The concept of two-dimensional feature surface helps to quickly refine the flue reconstruction ideas;double V-shaped confluence header has better drag reduction effect.According to the drag reduction effect of the optimal retrofit scheme,the theoretical calculation method is used to obtain the pipeline resistance characteristic curve of the second unit before and after retrofitting and the induced draft fan power consumption under several typical loads.The annual actual after flue reconstruction Income.In view of the problem of load distribution caused by the different characteristics of power consumption due to the different types of induced draft fans that are used in the two units sharing the tower,the power consumption characteristics of each unit in the two units are analyzed,Method,prioritization method and a combination of the two methods were obtained economic operation load distribution scheme that minimizes the total power consumption of the double unit induced draft fan.The results show that the load distribution scheme obtained by a combination of the two is the best solution and provides a reference for the energy-saving and economical operation of the power plant.