The Research On Model Of Monitoring Coal Grade For Utility Boiler Based On Flue Gas Compositional Analyse

The quality of coal plays an important effect on the safety stability and economy of boiler running. The real time inspection of coal quality enables worker to adjust boiler according to the variation of coal quality.Based on balance of substance and analysis of coal combustion chemical, the relationship between coal element ingredient and combustion gases ingredient was found out, and inspection model of coal quality element ingredient was established according to boiler running parameter. The inspection model of water as-received basis was established by analyzing the heat ingoing and outgoing of the coal grinding system; hypothesis-proof method was used to determine ash as-received basis, namely given an initial value of the ash as-received basis, checking by calculation of boiler thermodynamics. On the condition of known coal element ingredient, suppose the volatile matter is composed of carbon monoxide hydrogen firedamp and ethane, inspection model of volatile content was established via conservation of mass. By comparing the results of calculation and experiment, the relative error of carbon as-received basis is within -4.3-3.9%, water as-received basis within -4.1-4.6%, ash as-received basis within -4.7-3.9% and volatile content within -5.8-8.3%. The absolute error of calorific value is within -787.2 -654.5kJ/kg, and relative error within -4.6-3.8%.Some original work is as follows: on the basis of establishing coal element ingredient inspection model, the inspection model of volatile content was furthermore set up. The feasibility of the model was validated by experiment method, realizing the forecast of volatile content.