Energy-saving control system and method for boiler in thermal power plant

An energy-saving control method for a boiler in a thermal power plant, comprising:

• obtaining operating condition parameters of a boiler in a thermal power plant and predicting current boiler operating efficiency according to the operating condition parameters of the boiler in the thermal power plant;
• optimizing boiler input parameters based on a particle swarm algorithm, determining an optimal operating condition parameter combination according to optimization results, and setting adjustment steps of the optimal operating condition parameter combination according to operating efficiency predicted values;
• obtaining NOx emission data of the boiler in thermal power plant and calculating a NOx emission fluctuation degree according to the NOx emission data;
• setting an emission weight according to the fluctuation degree and setting a correction value of the optimal operating condition parameter combination according to the emission weight;
• regulating and controlling the boiler of the thermal power plant according to the correction value of the optimal operating condition parameter combination;
• wherein calculating a NOx emission fluctuation degree according to the NOx emission data comprises:
• determining NOx emission concentration according to the NOx emission data of the boiler in thermal power plant, and drawing a NOx emission concentration change curve of according to a change trend of the NOx emission concentration with time;
• creating a plurality of rolling time windows, setting window sizes of the rolling time windows according to a curve length of the NOx emission concentration change curve, and segmenting the NOx emission concentration change curve according to the rolling time windows;
• calculating NOx emission concentration average values in segmented rolling time windows, and drawing a NOx emission concentration average value change curve according to a NOx emission concentration average value in each of the rolling time windows;
• calculating a slope absolute value of two adjacent points in the NOx emission concentration average value change curve, and screening out data of slope absolute value with exceeding a first preset threshold;
• setting a proportion of a number of data of slope absolute value with exceeding a first preset threshold in the NOx emission concentration average value change curve as the NOx emission fluctuation degree;
• wherein setting an emission weight according to the fluctuation degree and setting a correction value of the optimal operating condition parameter combination according to the emission weight comprise:
• calculating a ratio of the NOx emission fluctuation degree to a preset allowable fluctuation degree, and normalizing the ratio of the NOx emission fluctuation degree to the preset allowable fluctuation degree;
• setting a normalized ratio of the NOx emission fluctuation degree to the preset allowable fluctuation degree as an emission weight, and multiplying the emission weight with a preset standard correction value to obtain the correction value of the optimal operating condition parameter combination;
• wherein setting an emission weight according to the fluctuation degree and setting a correction value of the optimal operating condition parameter combination according to the emission weight further comprise:
• obtaining operating condition parameter in a preset period according to boiler historical operating data, and calculating a correlation coefficient between each of the operating condition parameters and the NOx emission concentration according to the operating condition parameters in the preset period;
• taking the correlation coefficient between each of the operating condition parameters and the NOx emission concentration as an adjustment coefficient of each of the operating condition parameters, and adjusting a correction value of each of the operating condition parameters in the optimal operating condition parameter combination according to the adjustment coefficient of each of the operating condition parameters.