| Nowadays, the majority of small and medium sized chemical plants use fixed and fluidized bed as their mainly gasifier, which not only need high quality coal as raw material, but also cause serious pollution, facing a transition. In spite of superior performance, Pressurized entrained flow gasifier need expensive investment and maintenance costs, which is difficult to popularize during industry in a short time. Developing an appropriate technology to meet the needs of the market is a realistic need. In this paper, after well understanding of relevant technology, a cyclone pulverized coal gasification technology is proposed, obtaining first 545t/d gasifier design parameters.Firstly, by material balance calculations of 545t/d gasifier, related inlet parameters were known. Through furnace heat transfer calculations, it was feasible of wet slag trapping. By thermal calculation of refractory lining, it was feasible to resistance slag by slag. Then, a thermodynamic equilibrium model based on Gibbs free energy minimization is established by a software called Aspen plus to study the influence of oxygen/coal ratio, heat loss, steam/coal ratio, coal carbon conversion rates on synthesis gas quality. Getting conclusions as follow: oxygen/coal ratio plays a decisive role on outlet synthesis gas temperature. Reducing the carbon conversion rate will increases synthesis temperature. Heat loss increase will reduce synthesis temperature at the export and effect the synthesis gas composition change at a certain extent. Steam act as a regulators between temperature and composition in the gasification process. By analysis, the key parameters recommended that oxygen-coal ratio is 0.9kg/kg and steam coal ratio is 0.09kg/kg.Establish a 1:19.3 cold single-phase modeling experiment. Streamer tracer and water film tracer are adopt to measure the flow field in the furnace, studying the effect of overhead nozzle relative size and primary air rate on flow field inside the furnace, respectively. Under various operating conditions, the study found that these sections are produced in the furnace steady recirculation region, from the bottom up, \ "S\" shape, bent to a certain extent, adopting in-head nozzle relative size D1 / D = 0.45, formed in the cylinder at the top of the backflow zone range is larger; With the increase of primary air rate, backflow zone near to the cylinder center, but mainstream stick wall rigidity weakening. Comprehensive consideration, recommend using D1 / D = 0.45 and the operation condition of the primary air rate 20%.The numerical simulation method of cyclone furnace gas solid two phase flow characteristics are studied, respectively to study the relative size overhead nozzle and a wind rate’s influence on the flow characteristics in furnace. Research has shown that both the furnace under the condition of strong rotational flow field, furnace overhead nozzle relative size of D1 /D = 0.45 condition compared with D1/D = 0.25, on the cross section of maximum return rate and the back flow is larger, and pulverized coal particle has a longer particle residence time; With the increase of primary air rate, each location reflow area gradually weakened, and the jet rigidity is abate, but return closer to the cylinder center. Considering D1/D = 0.45 and the operation condition of the primary air rate 20%.is better.The results have been adopt in the design of first 545t/d atmosphere pressure cyclone gasifier of pulverized coal, which has been manufacturing, is expected to put into operation in October, 2015. |
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