The exhaust gas heat loss of coal-fired boiler is caused by the flue gas removed by final stage heat exchanger. The flue gas will take away a part of heat, mainly including the heat taken away by dry flue gas and the sensible heat with water vapor in the flue gas. What’s more, if the combustible gas in the coal-fired boiler is not completely burned, there will be heat loss as well. Therefore, this kind of heat loss mainly depends on the content of incomplete combustion products in the exhaust smoke.
Coal is one of the main fuels used by boilers, especially the coal-fired boiler. In order to reduce the production costs, we need to know whether the coal-fired boiler saves coal in operation.
If the boiler gives overpressure indicator which affects boiler's safe operation, depressurization measures should be taken. However, please pay attention that depressurization can not be too fast. After the overpressure problem of steam boiler is solved, we should check the internal and external parts of boiler to ensure that everything is going well.
The fuel of coal-fired boiler will release some harmful substances after combustion that are harmful to human body, but also pollute the environment. Therefore, the desulfurization treatment is required for coal-fired boiler, including desulfurization before combustion, desulfurization during combustion and desulfurization after combustion. The specific operating methods are different.
When regulating and controlling the coal-fired steam boiler, it will involve the banking-up operation which has a set of operating steps and points for attention. Strictly adhering to the operating steps will be helpful for the more efficient operation of coal-fired steam boiler and can extend its service life at the same time.
The industrial pulverized coal fired boiler is a new type of industrial coal-fired boiler focusing on pulverized coal combustion technology. The impurities are well removed when the grinding fitness of pulverized coal reaches 200 mesh. The pulverized coal is easy to be ignited and has few ash contents, which can enhance the complete combustion rate and reduce the burden of dust removal.
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
