Experimental Study On Optimized Import Coals Blending Combustion Of 300MW Domestic Coal-fired Boiler

In recent years,in order to expand the coal source and ensure the power production and power plant operation economy,coastal power plants are actively buying and consuming imported coal.In view of the complexity of imported coal,blindly blended combustion can easily affect normal operation of boilers,resulting in excessive emissions of pollutants,reducing boiler safety,stability and economy.To this end,before large-scale mixed burning of imported coal and domestic coal,comparatively detailed test work should be operated.On the premise of safe operation,1)the proportion of coal-fired coal imports is determined;2)the safety of the boiler,the economy mixed with imported coal and the principle of parameter control is determined;3)the impact of imported coal blending safety factors is determined.Through laboratory test,the physical and chemical properties of commonly used coal were tested.The milled index and wear index were obtained.The contents of trace elements and harmful elements in coal were obtained.The spontaneous combustion and the explosion characteristics etc.of imported coal,commonly used coal and blended coal.These had laid the foundation for the the field test.In view of instability of the power plant coal supply,field test process was divided into two phases.There are six kinds of coal used at the early stage,namely,PING 8 bituminous coal,PING 6 bituminous coal,PING 7 bituminous coal,Indonesia low-sulfur coal,Indonesia high-sulfur coal and Mongolia-mixed bituminous coal.There are 5 kinds of coal at the later stage,namely,PING 7 bituminous coal,Australian bituminous coal,Indonesia thermal coal(1),Indonesia thermal coal(2),Da-You 1 coal.According to the results obtained in the laboratory test,eight kinds of pre-mixed coal preparation have been designed,they are respectively: six at the early stage:(Indonesia low sulfur: PING 8 = 5: 5,Indonesia low sulfur: PING 8 = 6: 4,Indonesia low sulfur: PING 6 = 5: 5,Meng-Hun: PING 8 = 6: 4,Meng-Hun: PING 6=6:4?Meng-Hun: PING 7=3:7;and two at the later stage : PING 7: Australia: Indonesia 1 = 1: 1: 1,Da-You 1: PING7 : Indonesia 2= 1: 1: 1).In this paper,the problem of mixed blending of commonly used coal blending in coastal power plants was studied by field experiment.The characteristics of pollutant discharge,boiler efficiency,combustion economy and boiler coking in eight different mixed coal schemes were analyzed.The basic blending characteristics of the coal are obtained,and an excellent blending scheme is achieved to meet the requirements of the combustion index.Some of the schemes are not negative.The proportion of the imported coal is mixed.Which provides reference for the mixed coal blending of electric power enterprises.