There are many applications of hot water boilers. With the environmental protection requirements become stricter, the hot water boilers are mostly gas-fired. Therefore, it is important to know how to use the gas-fired hot water boilers safely and what are the maintenance methods.
In the boiler operation,the flue gas discharged from the flue gas duct has a certain temperature. However, the abnormal increase of flue gas temperature in boiler's flue gas duct is usually accompanied with other abnormal phenomena. In this regard, corresponding measures should be taken for adjustment based on the reason analysis.
Boiler produces heat via fuel combustion, so the burner is one of the important parts of boiler. And the air supply system is also an important component of burner. Whether the burner works well largely depends on its air supply system.
In the adjustment of boiler operation, on the basis of ensuring safe operation, economic operation must also be achieved to improve boiler efficiency. In general boiler units, the efficiency can basically reach more than 92%, and the total loss is less than 8%. The loss is: exhaust heat loss, generally 5-6%, followed by mechanical incomplete combustion heat loss is less than 1-1.5 %, heat loss and ash slag physical heat loss are about 1%. (Physical heat loss for high ash coal ash residue will be greater).
From the point of view of quantification of indicators, the key to improving boiler efficiency is to reduce smoke loss and heat loss due to incomplete combustion of machinery. Pay attention to the flue gas temperature changes. Excessive flue gas temperature will affect the efficiency of the boiler. Too low temperature may cause low-temperature corrosion of the air preheater. Therefore, it is necessary to strengthen the adjustment according to the load changes during operation. When t
Influencing factors of slagging on heating surface of boiler
(1) Ash characteristics of pulverized coal
Generally, the softening temperature ST of ash is used as the main indicator of slag formation. Coal with low ash melting point (ST<1200℃) is easy to slag. In addition, the slagging index also includes: silicon ratio, alkali-acid ratio, slagging index, limit viscosity and so on.
（2）Aerodynamic characteristics in the furnace
Improper air flow organization leads to flame center deviation, and the pulverized coal air flow flame adheres to the wall, causing local slagging of the water-cooled wall;
Improper air flow organization, forming flue gas retention vortex area and forming a reducing atmosphere (with CO), reducing the ash melting point and increasing the possibility of slagging.
Excess air coefficient: When the excess air in the furnace is too small, a reducing atmosphere may be generated, and the tendency of slagging will increase accordingly.
（3）Influence of boiler heat lo
1. During the start-up process of the burner, if the burner repeatedly alarms and locks, it should be found out the reason, find the fault and eliminate it, and then press the reset button to inherit the start. Note: The continuous press of the reset button should not exceed 10 seconds
2. If the burner is not successful in one combustion, the natural gas boiler induced draft fan should be restarted, and the second combustion can be started after 5 minutes of ventilation.
3. In the normal operation era, the burner close to the thermal equipment department (such as the connecting flange, etc.) will be very hot, to prevent the formation of burns. Do not place flammable materials in the vicinity to avoid causing fire.
4. During the operation of natural gas-fired boilers, it is necessary to closely supervise the working conditions of hot water circulation pumps and natural gas-fired boiler pressures, natural gas distribution bags, pipeline valves, pressure gauges, flow meters, and water
