Controlling the temperature within the appropriate range is important in fluidized bed operation. Here are some commonly used ways to control temperature:
Adjust. The total air volume fed into the primary and secondary air volumes: determined by the actual fuel composition. The dense phase zone temperature of the fluidized bed can be passed.
The temperature of the dense phase zone is determined by the combustion share of the dense phase zone. And regulating.
The ratio of one and two winds can effectively control the combustion share in the dense phase area, so as to achieve the purpose of controlling the bed temperature.
Appropriately reduce the primary air volume of the furnace and increase the amount of coal feed: this can increase the bed temperature. At the same time, it is necessary to check the coal feeding situation of the coal feeder frequently, and observe whether the flame and return device are normal.
Appropriately reduce the amount of limestone feeding: Since the limestone powder enters the bed, it must first absorb heat before the chemical reaction can begin, and the temperature of the bed will drop. During the ignition process, the amount of coal entering the furnace should be strictly controlled not to exceed 20% of the rated coal feed amount, so as to prevent the heat release of coal from exceeding the total heat absorption of the boiler and making the bed temperature too high.
Adjust the amount of material returned to the return device: prevent a large amount of recycled ash from returning into the furnace.
The main measures to reduce the bed temperature are: appropriately increase the volume of primary fluidized air, so that the heat stored in the bed is raised from the dense phase area to the dilute phase area by the primary air, so as to reduce the bed temperature. At the same time, it can also reduce the amount of coal feed, reduce the heat source in the bed, and also achieve the purpose of reducing the bed temperature.
Appropriately increase the secondary air volume: this can increase the turbulence in the furnace chamber, strengthen the exchange of cold and heat, and thus reduce the bed temperature.
When the operator adjusts the combustion, he should make a small number of adjustments to avoid large fluctuations in the bed temperature.
When putting slag, according to the differential pressure of the bed, it should be less and more frequently, so that the thickness of the bed is always kept within a reasonable range. After the slag discharge is completed, the operation personnel should carefully check and confirm that the slag discharge door is closed tightly before leaving the site, so as to avoid the situation that a large number of bed materials are discharged artesianly due to the slag discharge door not being closed tightly, the bed thickness is too low, and the bed temperature is difficult to control.