Argumentation Of Feasibility Of 2×410t/h Boilers Firing Shenhua Coal

In this report the 410t/h boiler in Tianjin Petromechanical Corporation firing the Shenhua Coal is analyzed in details including the analysis of the coal compositions, discussion of the slagging reasons, analysis of the reconstruction projects firing the similar coal kind, heat calculation of the Shenhua coal-fired boiler, resistance calculation of the smoke, calculation of the coal pulverizing system, design calculation of the combustors, analog calculation of the aerodynamic field in the boiler by the Fluent software, economical analysis of the boiler firing the Shenhua coal and comparison of the reconstruction quantities. After the overall analysis and comparison, it is suggested that the following two options should be given priority to:Option 1: the boiler with the single-fuel combustion system only firing the Shenhua coal, with the output of 380t/h and using warm air to transport pulverized coal ;Option 2: the boiler with multi-fuel combustion system firing 70% Shenhua coal, with the output of 400t/h and using warm air to transport pulverized coal .1. Option 1 has the following advantages:1) By adopting the boiler using warm air to transport pulverized coal and controlling the primary air under 160o, slagging will be very well controlled.2) The efficiency of the boiler will be improved. With the combustion system and pulverized coal system optimized, the boiler efficiency has been improved by 0.62%. The efficiency of the boiler using warm air to transport the pulverized coal is 0.26% higher than that of the boiler using the exhausted gas to transport the pulverized coal under the condition that they have the same output.3) The reconstruction quantities are little. With the boiler using warm air to transport the pulverized coal, the warm air will be extracted from the lower air preheater directly and its drying agents consist of hot air and circulating air without any cold air. Thus, the reconstruction quantities for this boiler is less than that of the boiler using exhausted gas to transport pulverized coal. However, the primary air box should be provided with an interface with the coal air pipe.4) Outstanding economic efficiency. The calculation of the economic efficiency in the reconstructed boiler's operation shows that the boiler using warm air to transport pulverized coal can save as many as RMB 19,540,000.99.2. Option 2 has the following advantages: 1) Better coking efficiency can be obtained by adopting the boiler using warm air to transport the pulverized coal and controlling the primary air temperature under 160o2) Improved boiler efficiency. In this way the boiler efficiency can be improved by 90.95%, 0.58% higher than that has not been constructed.3) Less reconstruction quantities. The reconstruction quantities of this boiler is almost the same as that of the boiler only firing the Shenhua coal with the output of 380t/h and using warm air to transport pulverized coal and can result in the obvious economic efficiency. This kind of boiler can save as many as RMB13,230,000.15 each year.