What should I do if the boiler coal feed is interrupted?

The boiler is a kind of energy conversion equipment, the energy input to the boiler is chemical energy and electrical energy in the fuel, and the boiler outputs steam, high-temperature water or organic heat carrier with a certain thermal energy. After the interruption, the specific operations are as follows: stop the faulty coal feeder, find the cause of the failure, and take corresponding measures to restore it; At the same time, the output of other coal feeders is increased to maintain stable combustion.

Dredging and blocking coal in a timely manner. Closely monitor the temperature in the coal feeder, and close the exit door of the coal feeder when it exceeds the specified value. If the coal level of the finished coal bunker is low, the output of the corresponding coal feeder should be reduced, and the coal should be notified at the same time.

If the finished coal bunker is burned out, the exit door of the coal feeder should be closed immediately and the coal feeder should be stopped to prevent the flue gas from returning. If the coal supply cannot be resumed in time, the boiler load should be appropriately reduced or the coal supply capacity of other coal feeding lines should be increased.

The water treatment work of the cast iron hot water boiler is also only to prevent the cast iron hot water boiler from fouling. However, due to improper treatment methods or because of his other conditions, there has been varying degrees of scale in a little boiler. In order to ensure the safe and economical operation of the cast iron hot water boiler, the scale should be removed in time.

At present, the descaling methods used include mechanical descaling method, pickling descaling method and alkali boiling descaling method. Mechanical descaling method: when there is loose scale and slag in the cast iron hot water boiler furnace, cool the cast iron hot water boiler after stopping the furnace, drain the furnace water, rinse with clean water, and then use a flat shovel, wire brush and motorized milling pipe to carry out descaling.

This method is exceptionally simple and is often used on small cast iron hot water boilers with simple fouling. However, the labor intensity is high, the descaling effect is poor, and the boiler body is easily damaged. Pickling and descaling method:

Most of the pickling and descaling methods use nitric acid to clean. The pickling solution is composed of *** plus corrosion inhibitor or nitric acid plus corrosion inhibitor. This pickling fluid eliminates scale from the boiler (hydrofluoric acid is added to remove nitrate scale) and minimally corrodes cast iron hot water boilers.

Pickling and descaling has the effect of dissolving, peeling and loosening. 3. Caustic boiling descaling method: Caustic boiling descaling method descaling, its effect is worse than that of pickling descaling method, but after alkali boiling because of the loose scale, it is difficult to remove the scale with ***, and it is still necessary to use the alkali cooking method to implement a treatment before pickling.

The caustic cooking method is simple to operate and has very little negative effect. The disadvantage is that the cooking time is very long, the consumption of chemicals is very high, and the effect is poor. Scale is the source of harm of cast iron hot water boilers, and it is quite important to do a good job in the anti-scale and descaling work of cast iron hot water boilers.

The difference between a hot water boiler and a steam boiler A hot water boiler is a boiler that produces hot water and is used for heating. The biggest difference between hot water boilers and steam boilers is that the latter develops and designs steam, and the other develops and produces hot water. Hot water boilers are divided into low-temperature hot water boilers and high-temperature hot water boilers.

Countries have different temperature boundaries for high-temperature water and low-temperature water, and our country takes 120. It is the cut-off temperature, that is, the outlet water temperature is more than the high-temperature hot water boiler, or the low-temperature hot water boiler. The parameter range of China's hot water boiler series is:

The rated thermal power is 116MW, the allowable working pressure, and the rated outlet temperature is 95. Because of its low working pressure, the hot water boiler does not need water level supervision and control, so its structure is relatively simple, the operation and maintenance are convenient, and the production is simple. But there are some special problems with its work:

It is necessary to ensure that the hot water of the boiler does not vaporize, which can avoid water hammer; The oxygen corrosion and external acid corrosion of the low-temperature heating surface are more serious. When there is a sudden power outage, the water in the pot does not flow and vaporizes.

This problem must be considered in the structural design, design, production and operation and maintenance of hot water boilers. According to the flow mode of hot water in the pot, there are two types of hot water boilers: forced circulation (direct flow) and natural circulation hot water boilers. Forced circulating hot water boilers usually do not have a cylinder, but are composed of those heated parallel pipes and headers, and the circulating power of hot water is provided by the circulating water pump of the heating network.

This type of hot water boiler has a compact structure, low steel consumption, and good hydrodynamic coordination. However, in order to prevent problems such as excessive hydraulic deviation and circulation stagnation, a higher flow rate in the tube has been adopted, coupled with a long stroke and a large resistance coefficient, the power consumption of boiler inlet water is high; At the same time, due to the small water capacity of the forced circulating hot water boiler, the resistance to accidents such as water hammer is poor due to the thermal inertia of the furnace when the water inlet is interrupted due to occasional power outages during operation. For that part, natural circulation hot water boilers are also used.

The natural circulation hot water boiler has a boiler barrel, and at the same time, due to the small density difference of the hot water, the low circulation pressure head and the low circulation flow rate, it is necessary to use a larger descending tube section and a higher circulation height.

The phenomenon of power interruption in the factory.

1) All motors running in the corresponding power supply section stop rotating, and there is no running sound; Voltmeter, ammeter indicate back to zero.

2) The electrical signal of each rotating motor flashes, the accident sound alarm, and the red light and green light are off.

3) If the boiler is extinguished, the furnace is darkened, and the air pressure returns to zero.

4) If the boiler is extinguished, the steam temperature, steam pressure, water level and steam flow rate will decrease.

Plant power interruption treatment.

1) Immediately pull the switch of each motor to the stop position and report the value length.

2) Automatically change to manual adjustment, pay attention to the monitoring parameters.

3) If the power supply of the whole plant is interrupted and the feed water pressure drops sharply, immediately notify the pump attendant to start the backup pump urgently, and close all the water discharge doors of the boiler to maintain the water level.

4) Prepare the ignition device and keep it ready to return to operation immediately.

5) Check the rotating machinery and make preparations before starting.

6) If the power is restored, the boiler should be ignited and put into operation immediately.

7) If the power supply cannot be restored for a long time, the boiler can be treated as a shutdown.

The details are as follows: the coal feed flow rate of a single or all coal feed lines is displayed. The control system sends out a fault alarm.

The oxygen content of the flue gas indicates a significant increase. The negative pressure of the furnace increases. The bed temperature, steam temperature, and vapor pressure drop significantly or sharply, and the main steam flow rate decreases.

The water level of the steam drum is low first and then high. The influencing factors of the arching of the flat-walled coal bunker and the cross-sectional shape of the rectangular and circular coal falling pipes in the process of coal falling are theoretically studied. Through the case analysis, the measures to solve the problem of coal bunker and coal pipe falling coal arching are proposed.

For coal bunkers, arch breaking devices can be set at its outlets or hyperbolic wall coal bunkers can be used. For the falling pipe, it can be divided into 2 sections. The operators on duty are required to conduct frequent inspections, and if they find that there is coal blockage, they should dredge it in time to ensure the stability of the operation of the boiler coal feeding equipment.

To solve the problem of coal cut-off in the coal feeder, we must first strengthen the management of coal burning and focus on the improvement and control of coal quality.

The outlet temperature of the coal mill is high, the current of the coal mill continues to decrease, the coal feed rate of the coal feeder of the faulty pulverizing system is automatically under the boiler fuel, and the output of other pulverizing systems increases the coal cut-off treatment of the coal mill, and the automatic adjustment of the coal feeder is lifted, and the coal feed amount is set to 20---25t h. , cancel the hot and cold air automatic, open the cold air door, close the hot air door, and maintain the air volume of 60t h. The automatic setting of the water level is modified to below -50, and the normal operation of other milling systems is monitored.

Immediately notify the dispatch to start the operation of the dredging machine on the spot, and notify the maintenance personnel to dredge the faulty coal feeder. During a coal break, when the current drops to a no-load value or vibration occurs, it is possible to consider raising the grinding roll to the upper limit. If it does not reply for a long time, stop the milling system and start the backup milling system.

Causes and preventive measures for coal plugging in finished coal bunkers: The main reasons are the strong cohesiveness of the lining or coal, the unreasonable structure of the coal bunker, and the small particle size of the coal. The measures are also formulated in response to the above reasons; The main factors causing coal blockage are:

The structure of the coal bunker is unreasonable; The noisy lining material is easy to bond; The cohesiveness of the coal liter teaser is strong; The particle size of the finished coal is on the fine side; The water content of coal is too high. The preventive measures include: improving the structural size of the coal bunker and eliminating the dead angle that is easy to bond; Use of anti-bond lining; Addition or improvement of coal bunker loosening, rapping equipment or layout; If conditions permit, try to increase the average particle size of the finished coal; Use dry coal with low water content; Burn coal that is not easy to stick to the knots.

The details are as follows: the coal feeder is stopped due to an electrical fault; Foreign matter is mixed into the coal and the reed is jammed by the coal feeder; Slippage or breakage of the coal feeder belt; Coal wetness causes blockage of the coal pipe; The finished coal bunker is not under the coal or empty bunker; Rotary feed valve plugging or malfunctioning. Treatment method after the interruption of boiler coal feeding:

Stop the faulty coal feeder, find out the cause of the failure, and take corresponding measures to restore it; At the same time, the output of other coal feeders is increased to maintain stable combustion. Dredging and blocking coal in a timely manner. Closely monitor the temperature in the coal feeder, and close the exit door of the coal feeder when it exceeds the specified value. If the coal level of the finished coal bunker is low, the output of the corresponding coal feeder should be reduced, and at the same time, the coal should be known through Maochang; If the finished coal bunker is burned out, the exit door of the coal feeder should be closed immediately and the coal feeder should be stopped to prevent the flue gas from returning. If the coal supply cannot be resumed in time, the boiler load should be appropriately reduced or the coal supply capacity of other coal feeding lines should be increased.

The details are as follows: the coal feeder is stopped due to an electrical fault; Foreign matter mixed into the coal will jam the coal feeder; Slippage or breakage of the coal feeder belt; Coal wetness causes blockage of the coal pipe; The finished coal bunker is not under the coal or empty bunker; Rotary feed valve plugging or malfunctioning. Treatment method after boiler coal feeding interruption:

Stop the faulty coal feeder, find out the cause of the failure, and take corresponding measures to restore it; At the same time, the output of other coal feeders is increased to maintain stable combustion. timely decay to accompany the dredging of coal blockage; Closely monitor the temperature in the coal feeder, and close the exit door of the coal feeder when it exceeds the specified value. If the coal level of the finished coal bunker is low, the output of the corresponding coal feeder should be reduced, and the coal should be notified at the same time; If the finished coal bunker is burned in the past, the exit door of the coal feeder should be closed immediately and the coal feeder should be stopped to prevent the flue gas from returning; If the coal supply cannot be resumed in time, the boiler load should be appropriately reduced or the coal supply capacity of other coal supply lines should be increased.

1. The steam pressure drops, and the steam output is weak. superheating temperature and pressure drops; 2. The furnace temperature is reduced; 3. Increased oxygen content; 4；The exhaust gas temperature decreases and other obvious reactions.