Study On The Impact Of The Particle Size On The Ignition Of The Pulverized Coal And The Role Of Sub-size Pulverized Coal In The Low Oil Ignition

Our country is facing increasingly serious shortage of oil. In the annual consumption of oil resources, huge amount of fuel is consumed up for boiler ignition and stable combustion. Reducing fuel consumption of the coal-fired power is the key of fuel-efficient. In the ignition process of the boiler burning the coals difficult to ignite such as lean coal and anthracite, conventional oil gun needs to consume large quantity of fuel. But at present, free oil ignition or low oil ignition technology can not meet the needs of direct light of low-volatile pulverized coal. Therefore, R&D of new technologies is needed in this area. This paper firstly introduces several non-oil and less oil ignition technologies widely used home and abroad. However, food results can not play in igniting lean coal and anthracite with those technologies. Therefore sub-size pulverized coal low oil ignition technology is proposed.According to the sub-size low oil ignition technology, finer particles of the pulverized coal are easier to be ignited. In the low oil ignition and combustion of coal, pulverized coal is separated through particle size and then sent into low oil ignition burner. Firstly the flame of small oil gun ignites the finer particles. Then, the flame of the oil and finer particles ignites the large particles. This technology is used to meet the direct firing of the low-volatile coal by the small oil gun.The ignition experiment of sub-size pulverized coal of different lean coal and anthracite on the test bench of ignition furnace,is the base of the technology and devices development of sub-size low oil ignition. After introducing the coal ignition criterions, influence factors, and the test methods of the ignition temperature, the ignition temperature and pollutants determinations of sub-size pulverized coal of lean coal and anthracite are carried out on the test bench of ignition furnace. Then the results are analyzed. The results of the ignition temperature show that separating the pulverized coal and firing finer particles first is possible to improve the ignition conditions. At the same time reducing the amount of air also helps to reduce the ignition temperature. The results of the ignition pollutants show that separating the pulverized coal hardly impact on the NO_x formation. And the amount of the SO₂ released from the finer particles is less than that the original particles, while the amount of the SO₂ released from the large particles is more than that from the original particles.Finally, the sub-size separator of pulverized coal and the test bench of the small oil gun are preliminary designed. And the work which is needed to be improved in the next experiment is proposed.