The Study And Evaluation On Furnace Aerodynamic Field Of Burner Arrangement For 600MW Utility Boiler

There were problems always for large boiler with corner tangent fired .Because the furnace aerodynamic field was not so reasonable ,it was easy to make slag on the water wall and high-temperature corrosion due to gas flow closing and scouring the wall in the operation. It was easy also to make local overeating and tube bursting for heat surface owing to considerable speed difference side to side in furnace exit. Aiming those problems ,a long-term cold model research was carried in a large scale experimental facility. The prototype of this research was HG-2023/17.6-YM4 boiler. The cold model test facility was designed and erected on the scale of one-fifteenth. According to the experiment purpose, we designed the test program and test course. By means of hot wire anemometer(HWA) to measure the section speed in various areas of burners and furnace exit as well as final reheater exit. Adopting streamer tracing of yarn to observe and analyze the whirl characters of air-flow under the condition of various burner nozzles in operation,which were simulating the actual utility boiler in up and down its load. The following conclusions have been got: 1. Adopting partial burner nozzles counter injecting could improve dynamic field in furnace obviously and make the whirl diameter of flow-gas in furnace reduced, and the distribution of flow-gas in furnace be better. 2. The ratio of total inversing tangent momentum-moment could reflect the situation of the aerodynamic field in furnace better. The ratio value R was selected as about 0.7 appropriately when the affect of the total inversing tangent momentum-moment upon the whirl diameter of gas flow in furnace and the flow distribution index in the furnace exit were considered comprehensively. 3. The whirl flow-gas had great inertia, once the whirl direction was determined, it was very difficult to change the original whirl direction, for the corner tangent fired boiler with partial second air inversing-tangent jets, the sequence to put in operation of the burners at various levels was very important in order to avoid the flow inversing whirl in furnace. When the boiler rose its load the jets without inversing tangent should be put in service at first, and when the boiler reduced its load, the jets with inversing tangent should be out service earlier. This paper for above research was the essential reflection of true situation for aerodynamic field in furnace. It could provide a certain guide and reference for select of burner arrangement and optimization of boiler opertion.