| NOx control is an emergent problem at present, since its influence on environment; climate and people's health become increasingly bad. Power plants' coal combustion is the main source of NOx emission. So far as the problem appeared, people still understand little about the mechanism of the Fuel-NOx' production and complexity. This dissertation deeply studied the pyrolysis characteristics of Fuel-N in anthracite, bituminite and coal water slurry and their Fuel-NOx' formation peculiarity. All these can offer some theoretic bases and data support to low NOx combustion system's development and design.In this dissertation, experimental study on Fuel-N pyrolysis law of anthracite, bituminite, and coal water slurry and black liquid CWS was made. Main attention was fixed on the factors such as temperature, stay time, reaction condition, particle diameter and coal types. The effect of nitrogen-containing species (HCN,NH3), which may divert to NOx in the reaction, was also deeply researched. This paper first analysed the pyrolysis law of Fuel-N in coal water slurry and black liquid CWS, and found that, comparing to coal powder, the Tar-N content decreased and NH3 yield increased. This result proved the characteristic of low NOx emission of coal water slurry from more deep mechanism.Fuel-N's emission is a very complex procession. Its dependent factors covered more fields. So, it was difficult to build an universal model to forecast Fuel-N's distribution in fuel. Fortunately, NN can be fit for this problem. BP NN was used in this paper. Although microcosmic mechanism was not fully understood, satisfying results were gained through training NN to use experimental data and accumulate relative knowledge.Pyrolysis combustion experimental method was put forward here. Anthracite, bituminite, coal water slurry and black liquid CWS' volatiles and half-char were studied using rapid heating in fixed tube furnace. Coal types, temperature, excessive air ratio and particle diameter's influence on coal powder's NOx production and on transform ratio of char-N and volatiles-N. Secondary reaction model of char-N and volatiles-N was built. Evaluation method of char-N and volatiles-N's relative contribution to NOx production was also offered here.NOx emission laws of anthracite, bituminite-fired boilers were studied here. Experimental study was made in the first coal water slurry fired boiler in China. Optimized methods were offered here to CWS fired boiler's low NOx emission operation.Fe and Ca's influence on NOx formation was discussed in this paper. Coal types, temperature, excessive air ratio's impacts on NOx production were regarded after additives' addition. It was found that CWS with CaO as additive maybe a kind of good reburning fuel.Using mathematics model, this dissertation simulated NOx production of a 0.25MW boiler, studied temperature field and NOx concentration field's distribution and compared the results with the test data. When experimental data was used as initialized condition, calculation accuracy can be improved and provided reference for practical engineering's numerical simulation.
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