Questions&Answers

Possible reason:

• The clearance of cyclone ventilation is blocked by carbon deposit, which leads to poor ventilation.
• Nozzle is dirty, blocked or worn.
• The throttle setting angle is too small.
• The distance between the tip of the ignition match and the leading edge of the oil nozzle is not appropriate (too protruding or retracted).
• Oil gun solenoid valve is blocked by sundries (small oil gun).
• The oil is too viscous to flow easily, or the filter system is blocked or the oil valve is not opened, so that the oil pump does not absorb enough oil and the oil pressure is low.
• The filter screen of the oil pump itself is blocked.
• There is too muchwater in the oil (abnormal boiling noise in the heater).

Treatment measures include:

• Cleaning; Clean it first, if problem notfixed, replace a new one; Turning down test; Adjust the distance (preferably 3~4mm); Remove and clean (clean the parts with diesel oil); Check the pipeline, oil filter and thermal insulation equipment; Remove the peripheral screws of the oil pump, carefully remove the outer cover, take out the oil net inside, and soak it with diesel oil; Try it with new oil.

Possible reasons:

The damper air volume setting of the big flame is too high.

The microswitch of the oil valve of the big flame (the group outside the damper) is set inappropriately (the setting is higher than the air volume of the damper of the big flame).

Oil viscosity is too high to be atomized (heavy oil).

Improper spacing between cyclone disc and oil nozzle.

The big flame oil nozzle is worn or dirty.

The heating temperature of the reserve tank is too high, which causes the steam to make the oil pumping not smooth.

The oil in the oil-fired boiler contains water.

Solutions:

Gradually reduce the flame; raise the heating temperature; adjust the distance (between 0 and 10 mm); clean or replace; set the temperature at about 50℃. change oil or drain water.

Possible reasons:

The cut-off valve in the oil circuit is closed or the oil intake is insufficient, or the oil filter is blocked.

The oil inlet temperature is low, the viscosity is too high or the oil inlet temperature of the pump is too high.

The oil pump is out of order.

The bearing of the fan motor is damaged.

Fan impeller is too dirty.

Solutions: 

① Check whether the valve in the oil pipeline is open, whether the oil filter works normally, and clean the filter screen of the pump. ② Raise or lower the oil temperature. ③ Replace the oil pump. ④ Replace the motor or bearing. ⑤ Clean the fan impeller.

Possible reasons:

• There is carbon slag and oil in the gap of ignition match.
• Ignition match is broken, wet or
• The distance between ignition match is wrong, too long or too short.
• The insulation sheath of ignition match is damaged and short-circuited to the ground.
• Malfunction of ignition cable and transformer: cable disconnection and connector breakage cause short circuit during ignition; Transformer disconnection or other faults.

Five possible solutions: clearing, replacing, adjusting distance, changing cables or change transformers.

The working process of the flame detection device is as follows: the flame detection device near the ignition oil gun is composed of optical fiber, which senses the fire and generates optical signal. The optical signal is transmitted to the signal amplification circuit of the ignition program-controlled cabinet, which is amplified into electrical signal, and the switch value is transmitted to the display screen of the distributed control system (DCS), so that the operator can know the working condition of the ignition oil gun.

The boiler boosting process is actually a warming process, the pressure corresponds to the saturation temperature. The saturation temperature is not directly proportional to the pressure, but with the increase of the pressure, the saturation temperature starts to increase rapidly, then becomes slower and slower. Therefore, in order to ensure that the temperature difference between the upper and lower walls of the steam drum is within the specified range, the boosting speed must be slow at the initial stage of ignition. In addition, in order to avoid the superheater burning out at the initial stage of ignition, this is also the case.

In the middle and late ignition period, the boosting speed is faster and faster, but the heating speed is basically unchanged, so the boosting speed can be accelerated, the boosting time can be shortened, and the fuel can be saved.

(1) Adequate air supply.

(2) Maintain a high enough temperature.

(3) Proper mixing of air and fuel.

(4) Sufficient burning time.

On the one hand, the mixing, mass transfer and heat transfer caused by the entrainment of high-temperature flue gas in the furnace by airflow. On the other hand, the high-temperature flame radiation heat exchange in the furnace. Among them, the entrainment of pulverized coal airflow is the main one.

Change some adjustable parameters and control modes (i.e. fuel supply mode and air distribution mode) in a planned way, comprehensively adjust the combustion conditions and measure some single index values, and then scientifically analyze the obtained results, compare them from the aspects of economy and safety, determine the best operation mode and calibrate the operation characteristics of the equipment. Such experiments, measurements, analysis and research work are boiler combustion adjustment tests.

For burners with four corners, they should run symmetrically in the same row, with no missing corners and even output. And try to keep the outlet airflow speed and load of each burner uniform. Or change the flame center position by changing the inclination angle of the oscillating burner or the ratio of the upper and lower secondary air.

Early ignition may burn out the nozzle or cause coking near the nozzle. Late ignition will cause the flame center to move up, which may cause coking in the upper part of the furnace, increase the steam temperature and even interrupt the flame.

During the operation of the boiler, if the flame center in the furnace deviates, the flame fullness of the whole furnace will deteriorate. On the one hand, there is a big smoke temperature difference in front, back, left and right of the furnace, which causes uneven heating of the water wall and may destroy the normal water circulation. On the other hand, the flue gas temperature difference between the left and right sides of the furnace outlet causes the temperature on one side of the furnace outlet to be high, which leads to the overheating of the superheater and other heating surfaces on this side and tube explosion. Therefore, attention should be paid to adjusting the position of the flame center in the operation so that it is located in the center of the furnace.