Soft Sensor of Heating Extraction Steam Flow Rate Based on Frequency Complementary Information Fusion for CHP Plant

Abstract

Heating extraction steam (HEXTR) flow rate is the key parameter to determine the heat load of a combined heat and power (CHP) plant and the safe operation area of the steam turbine of CHP plant. Due to the difficulty of direct measurement, a soft measurement method of this flow rate is proposed. First, three calculation methods based on different principles are given: the Flügel formula of the steam turbine method, the butterfly valve flow characteristics method, and the improvement of heat balance characteristic of the turbine method. Then, a soft-sensing method through frequency complementary information fusion is proposed to combine the advantages of the three methods. The specific fusion algorithm uses Flügel formula of the turbine as a static model, the heat balance characteristic of the turbine to correct the coefficient in the model, and the butterfly valve characteristic to realize dynamic compensation. Finally, the proposed soft sensor is applied in the monitoring system of a typical 330 MW CHP plant. The actual operating data shows that the relative static measurement error of the soft sensor is less than 1% and the dynamic response is as fast as power load change.

Virtual Soft Sensor of the Feedstock Composition of the Catalytic Reforming Unit

“…The application, algorithmic and mathematical bases for these sensors are very diverse and are mainly based on neural networks, regression methods, and composition prediction. The paper by Tian et al (2021) [12] presents soft sensor applied in the monitoring system of a typical 330 MW CHP plant. This approach uses the turbine's Flugel formula as a static model, the turbine's heat balance characteristic to correct the coefficient in the model and the butterfly valve characteristic to realize dynamic compensation to realize the soft sensor.…”