Research on the measurement method of fuel feeding temperature during circulating fluidized bed boiler's start‐up

Abstract

AbstractCirculating fluidized bed (CFB) boiler is a high‐efficiency and clean combustion technology that has been developed rapidly in recent years. During the start process, only after the furnace temperature is heated up with fuel oil higher than the fuel feeding temperature, fuel can be fed into it, otherwise, it will easily lead to deflagration accidents in the furnace. While adding fuel too late will increase the unnecessary cost of fuel oil. There are three main methods for measuring fuel feeding temperature in the CFB boiler. The thermogravimetric analysis‐derivative thermogravimetry (TG‐DTG method has the problem of a large gap between the measurement results and the actual boiler fuel feeding temperature. Although the measurement results in the CFB test rig are more accurate, its procedure is more complex and costly. The method of on‐site debugging and measurement has disadvantages such as high measurement cost and poor measurement repeatability. For this reason, this paper designs a simple method to measure fuel feeding temperature in CFB boiler, which has standard operability and lower test cost. The measurement results of variable fuel types were compared with the measurement results of the above three methods, which prove that the results of all samples are close to those in the actual CFB boiler with error within 40°C. It is confirmed that this method can accurately measure the CFB boiler fuel feeding temperature, which is of great significance to the operation of the CFB boiler.