In the biomass boiler, some high exhaust gas temperature cannot be avoided. Measures to reduce the high exhaust gas temperature of the boiler

　　When the boiler runs at full load for 72 hours, the exhaust gas temperature of the boiler is relatively high, and the highest relatively stable value is about 164°C. After adjustment and analysis, it is believed that the high exhaust gas temperature of the boiler is a comprehensive problem, which needs to be comprehensively improved from the aspects of meter calibration, soot blowing, combustion adjustment and soda water system adjustment.

　　line governance. The following measures are recommended:

　　1. By observing that the inlet temperature of the bag filter shows 145°C on the spot, it is found that the displayed value of the smoke exhaust temperature on the DCS screen is 10°C higher. The reason for the analysis is that there is a problem with the compensation method and calculation method of the thermocouple. At the same time, after calculating the heat exchange of the low-pressure air preheater, it is found that the air flow value is too small, which requires

　　Re-calibrate the air volume and air pressure. In addition, the display of the two oxygen meters is quite different, and the temperature display value at the outlet of the high-pressure air preheater obviously does not match the actual value. Therefore, the corresponding meter needs to be re-calibrated.

　　2, put the soot blower into operation. When the boiler is just put into operation, soot blowing should be carried out at least once a day, and the boiler is operating normally, soot blowing should be carried out at least three times a day. At the same time, the number of soot blowing is related to the ash content in the fuel.

　　3. Change the operation adjustment mode of the low-pressure air preheater circuit and the high-pressure air preheater circulation circuit, and try to make the flow on the water side close to the design value.

　　4. According to the design data of the outlet temperature of the superheater and desuperheater at all levels and the design data of the spray desuperheating water volume, the second-level desuperheating water volume is the largest, the third-level desuperheating water volume is the second, and the first The graded desuperheating water is the smallest.

　　5. Carry out combustion adjustment to reduce the primary air volume, increase the secondary air volume, and reduce the negative pressure value of the furnace (the negative pressure value in actual operation is about -500Pa, and it is maintained between -50~-250Pa.

　　6. ​​Keep the deaerator running at the rated pressure (0.588MPa) and ensure that the feed water temperature is about 210°C. Maintain a higher pressure of the deaerator, and absorb more heat from the flue gas with the municipal low-pressure flue gas cooler.