Ultralow NOx emission system and method for heating furnace

Abstract

The invention belongs to the field of metallurgical industry furnaces and kilns, and relates to an ultralow NOx emission system and method for a heating furnace. The ultralow NOx emission system is composed of the heating furnace, a burner, a nitrogen pipeline, an air pipeline, a fuel gas pipeline, a flue gas NOx detection device and a control system, a nitrogen cut-off valve and a regulating valve are controlled by NOx detection values in an interlocking mode, and the control system controls opening and closing of the nitrogen pipeline and nitrogen flow according to the NOx detection values; and when NOx exceeds the emission standard, the nitrogen flow is intermittently regulated upwards, when the NOx is lower than the emission standard and higher than 0.9 time of the emission standard, the nitrogen flow is kept unchanged, and when the NOx is lower than the 0.9 time of the emission standard, the nitrogen flow is intermittently regulated downwards. The ultralow NOx emission system and method for the heating furnace can effectively solve the problem that the NOx of the existing heating furnace intermittently exceeds the standard, the system and the method are simple and efficient, and a small amount of nitrogen is used in the production process, so that the one-time investment cost and the operation cost are low; and the system and the method can be used for upgrading and reconstruction of an existing system, secondary pollution is avoided, NOx emission of the heating furnace is flexibly and effectively reduced, and good economic and social benefits are achieved.

Description

technical field [0001] The invention belongs to the field of furnaces and kilns in the metallurgical industry, and relates to an ultra-low NOx emission system and method for a heating furnace. Background technique [0002] Metallurgical heating furnace is one of the commonly used equipment in the steel production process. In recent years, with the increasingly prominent environmental protection issues, the NOx emission requirements for heating furnaces have become more and more stringent. At present, most metallurgical heating furnaces use ultra-low NOx burners. When the production rhythm is stable, NOx can basically meet the emission requirements. However, the working conditions of the metallurgical heating furnace are complex and changeable. As a result, NOx intermittently exceeds the standard. At present, the commonly used method is that operators continue to intervene manually. This not only increases the workload, but also the effect of controlling NOx emissions is not ...

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Problems solved by technology

[0002] Metallurgical heating furnace is one of the commonly used equipment in the steel production process. In recent years, with the increasingly prominent environmental protection issues, the NOx emission requirements for heating furnaces have become more and more stringent. At present, most metallurgical heating furnaces use ultra-low NOx burners. When the production rhythm is stable, NOx can basically meet the emission requirements. However, the working conditions of the metallurgical heating furnace are complex and changeable. As a result, NOx intermittently exceeds the standard. At present, the commonly used method is that operators continue to intervene manually. This not only increases the workload, but also the effect of controlling NOx emissions is not very good, and the production of enterprises is also affected. If more out-of-stock equipment is added, due to The heating furnace generally exceeds the standard intermittently for a short time, and the application efficiency of the denitrification equipment is not high, which increases the production cost and the complexity of the process system. Therefore, a simple and effective system and method that can deal with the intermittent nitrogen oxide exceeding the standard of the heating furnace is needed

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