Fuel freezing point is the temperature at which the fuel loses fluidity. It is an important index that indicates the fuel flows at low temperatures. It often refers to the maximum temperature at which the oil surface remains stationary within 1 minute. The higher the fuel freezing point, the lower the low-temperature fluidity. When the oil temperature is below the freezing point, it cannot be transported in the pipeline.
Four factors are related to the failure of the draft fan of the biomass-fired boiler. The factors are electric, electrical motors, dampers and induced draft fans. Therefore, if the draft fan breaks down, you can check the electric and electrical motor first, then you can check the damper and the induced fan.
Although biomass-fired boilers are environment-friendly boiler products, there are also some situations that biomass-fired boilers can’t be used. Main reasons as follows:
Fuel restrictions: The fuels that contain synthetic compounds can’t be used as the fuel of a biomass-fired boiler, such as waste wood furniture, waste paper, production and domestic waste.
1. If there is air in the pump or suction pipe, the air should be discharged.
2. If the depth of the bottom valve immersed in the water is not deep enough, the depth should be increased.
3. If the rotational speed is too slow or the conveyor belt is too loose, the rotational speed should be adjusted and the conveyor belt should be tightened.
4. If the impeller, suction pipe and bottom valve are blocked by dirt, you should check the pump body and clean the dirt.
5. If the height of water conveyance exceeds the regulations too much, the pump head should be adjusted to the specified range.
1. Sufficient furnace temperature: Sufficient fuel combustion of biomass-fired boilers firstly requires high furnace temperature. The temperature should meet the requirements of sufficient fuel combustion. Besides, the combustion speed is required to be proportional to the temperature. Moreover, the furnace temperature should be raised as much as possible on the premise that slag is not formed in the furnace.
1. The fuel volume is 1 / 30 ~ 40 of the raw material volume after molding;
2. The specific gravity is 10-15 times of the raw material, and the moisture content is between 12% and 18% (the moisture content of coal is below 10-15);
3. The net calorific value can reach 3500-4500 kcal (the net calorific value of class II bituminous coal is 3700-4700 kcal / kg);
4. The ash content is less than 10% (the ash content of coal is more than 20%);
5. Volatile matter ≥ 65.62% (volatile matter of class II bituminous coal≥20%).
6. Biomass fuel belongs to renewable clean energy, which is the same as wind energy and solar energy. The biomass fuel is rich in resources, it can ensure the sustainable use of energy.
7. The sulfur content and nitrogen content of biomass fuel are low, the amount of SOx and NOx generated in the combustion process is low.
Advantages: the efficiency of electric dust collector can reach up to about 99%; large gas handling capacity; low flue gas flow rate, low resistance and low operation costs. Shortcomings: complex structure; large size, large area covering; high investments; complex maintenance; special requirements for dust resistance.
The economizer is a heat exchanger equipment which utilizes heat recovery of flue gases to heat feedwater. It can increase boiler efficiency, reduce the temperature of flue gas and save the fuel by absorbing recovery of flue gases. Besides, the feedwater is heated through the economizer before it is supplied into steam drum to decrease the thermal stress of the steam drum wall caused by temperature difference, which can improve the operating conditions of steam drum and prolong the service life of the steam drum.
