Petroleum residuum burning boiler and combustion method thereof

Abstract

In a petroleum residuum burning boiler including: a high-temperature reduction combustion chamber to which petroleum residuum fuel and primary combustion air are supplied and in which combustion is performed at a temperature of 1,300° C. or more and an air ratio of less than one; and a low-temperature oxidation combustion chamber which is connected to the high-temperature reduction combustion chamber and in which combustion is performed at a temperature of less than 1,300° C. and an air ratio of one or more, an assist gas is supplied to the high-temperature reduction combustion chamber, and unburned carbon of a combustion gas of the petroleum residuum fuel is gasified by a water gas reaction by using steam, generated by combustion of the assist gas, as a gasifying agent.

1 . A petroleum residuum burning boiler comprising:
 a furnace body including
 a high-temperature reduction combustion chamber in which combustion is performed at a temperature of 1,300° C. or more and an air ratio of less than one and 
 a low-temperature oxidation combustion chamber which is connected to the high-temperature reduction combustion chamber and in which combustion is performed at a temperature of less than 1,300° C. and an air ratio of one or more; 
   a burner that supplies petroleum residuum fuel and primary combustion air to the high-temperature reduction combustion chamber;   a two-stage combustion air supply nozzle that supplies two-stage combustion air to the low-temperature oxidation combustion chamber; and   an assist gas supply nozzle through which an assist gas is supplied to the high-temperature reduction combustion chamber, the assist gas containing a component which generates steam by combustion, the steam being used as a gasifying agent for unburned carbon of a combustion gas of the petroleum residuum fuel.   
     
     
         2 . The petroleum residuum burning boiler according to  claim 1 , wherein the burner is a coaxial mixed combustion burner including the assist gas supply nozzle and a main fuel supply nozzle through which the petroleum residuum fuel and the primary combustion air are supplied. 
     
     
         3 . The petroleum residuum burning boiler according to  claim 1 , wherein the assist gas is a by-product gas generated in a petroleum refining step. 
     
     
         4 . A combustion method of a petroleum residuum burning boiler,
 the petroleum residuum burning boiler including:   a high-temperature reduction combustion chamber to which petroleum residuum fuel and primary combustion air are supplied and in which combustion is performed at a temperature of 1,300° C. or more and an air ratio of less than one; and   a low-temperature oxidation combustion chamber which is connected to the high-temperature reduction combustion chamber and in which combustion is performed at a temperature of less than 1,300° C. and an air ratio of one or more,   the combustion method comprising:   supplying an assist gas to the high-temperature reduction combustion chamber; and   gasifying unburned carbon of a combustion gas of the petroleum residuum fuel by a water gas reaction by using steam, generated by combustion of the assist gas, as a gasifying agent.   
     
     
         5 . The combustion method according to  claim 4 , wherein the assist gas and a mixture of the petroleum residuum fuel and the primary combustion air are coaxially supplied to the high-temperature reduction combustion chamber. 
     
     
         6 . The combustion method according to  claim 4 , wherein the assist gas is a by-product gas generated in a petroleum refining step.