Coal consumption is the main economic assessment indicator for thermal power plants, but the heat generation and total moisture of the fuel used for internal combustion in different stages of the same boiler vary among different plants and different boilers within the same plant. That is, the low heat generation of the fuel and the truly available effective heat value in the fuel are also different. In order to adopt a unified standard as the basis for calculating coal consumption, we have designated coal with a base low calorific value of 29271KJ/Kg as standard coal, that is, every 29271KJ/Kg of heat is converted into 1Kg of standard coal. In this way, the coal consumption of various low calorific values is unified to the standard coal consumption.

Standard coal consumption: b=(Qnet, ar · G)/(29.27E)??? Unit: Kg/(Kw · h)

In the formula: G - weight of coal (applied coal) entering the furnace, kg

Qnet, ar - Low level heat generation calculated based on received basis, MJ/Kg

E - Power generation, Kw · h

29.271- Calorific value of standard coal, MJ/Kg

Introduction to Low Volatile Coal:

According to the quality standards for coal used in power generation in China, dry ash free coal with a volatile content Vdaf less than 20% is considered low volatile coal, which is less than 6 5% is ultra-low volatile coal. The ignition of coal is related to the quality and quantity of volatile matter. As the degree of coalification increases, the content of volatile matter decreases, and the ratio of volatile matter to heat generated by coal decreases, making coal ignition difficult; The petrographic structure of coal also changes, and the deepening of coalification makes the structure compact and stable, with low porosity, which weakens the grinding performance of coal, reduces reactivity, and deteriorates burnout.

Therefore, the characteristic of low volatile coal is that it is difficult to ignite and burn out, requiring higher ignition and burn out temperatures as well as longer burn out times. Research has shown [3] that the ignition of anthracite occurs on the particles, and volatile matter is precipitated during further combustion, with little impact on ignition. To achieve satisfactory combustion results, anthracite coal must be ground finer to increase its surface area, in order to accelerate ignition and combustion.. Generally speaking, Vdaf can roughly determine the difficulty of its ignition and burnout. However, in long-term research on the combustion of low volatile coal in China, it has been found that even two types of coal with identical Vdaf have significantly different combustion characteristics. Therefore, there must be more reliable discriminative data. Research has shown that using the ignition temperature IT of coal powder airflow to determine the difficulty of ignition is more accurate, with IT<700 ℃ being the coal that is more prone to ignition; IT=700-800 ℃ for medium ignition coal; IT ≥ 800 ℃ is a coal that is difficult to ignite. Among the many low volatile coal in our country, the most difficult to burn are Jiafu anthracite from Fujian and Wannian anthracite from Hebei. Both belong to extremely low volatile coal, with Vdaf of about 4% and ignition temperatures of IT of 970 ℃ and 1100 ℃, respectively, making them extremely difficult to ignite; The burnout index RJ is 2 94 and 2 32, extremely difficult to burn out. Jiafu smokeless coal is also a medium slag prone coal with low ash melting point.

To ensure the stability of ignition and combustion, the primary task is to take effective measures to ensure timely ignition of coal powder airflow