An Experimental Research On Converting To Burn Bituminous Coals In 1025t/h Lean Coal-fired Boiler

Affected by the distributing irrationality of coal resources and transport capacity deficiency of coal markets in China, a 1025 t/h lean coal-fired boiler had to convert to burn bituminous coals. However, as the coal-fired boilers are usually designed according to the specific coal, the change of coal quality will exert a detrimental influence on the safety and economy of boilers'operation. Therefore, in order to widen the applicability to the coal in this power plant, lower the electricity cost, cut down the contamination emissions, it is necessary to investigate the feasibility of converting to burn bituminous coal in this boiler and propose ways to resolve the problem.First of all, the experiment researchs were adopted to measure the coal element composition of PS coal and DY coal from the power plant and then understand the coal characteristics. After that, through the thermogravimetric experiment and drop tube furnace, the combustion characteristics of bituminous coals were studied. And the experiment results were that the combustion chatacteristics of PS coal were close to those of the designed coals and better than DY coal.Secondly, the thermal calculation was carried out to analyze the influences on burner and coal pulverizing system. After that, based on the experiment datas and analysis results, this paper proposed a rebuilding scheme of reforming the coal pulverizing system properly and adjusting the burner.Finally, based on the calculation and analysis above, the power plant processed a trial test of PS coal. And the test results revealed that the boiler can operate safely even some problems were found. To solve those problems, this paper advanced the further reconstruction suggestions for the overhaul repair.