US 2026/0202054 A1 · METHOD FOR REDUCING NITROGEN OXIDE EMISSION AND COMBUSTION SYSTEM

Abstract

The present invention relates to the field of flue gas nitrogen oxide emission, and in particular to a method and a combustion system for reducing nitrogen oxide emission. Introducing non-nitrogen inert gas as a combustion diluent to establish ignition; when the amount of circulation flue gas reaches a designed value, the introduction of the non-nitrogen inert gaseous diluent is stopped; and by means of circulation of a part of flue gas and a part of CO2 in the flue gas, the internal circulation of the whole process system is ensured. The present invention achieves the objectives of reducing the nitrogen oxide emission and saving the fuel, thereby saving the energy, protecting the environment, fundamentally solving the emission problem of NOx in the flue gas, and achieving carbon reduction.

Claims14

Dependent claims

A method for reducing nitrogen oxide emission, characterized by comprising reducing N2 content in a system by the following manners:

I. introducing a non-nitrogen inert gaseous diluent to replace gas inside a furnace;
II. mixing a non-nitrogen inert gaseous diluent and oxygen gas, introducing the mixed gas into the firebox to be mixed with a fuel, and then igniting the mixture to initiate combustion;
and/or
III. cooling at least a part of flue gas from the flue gas outlet to obtain a cooled flue gas, mixing a part of the cooled flue gas and remaining flue gas from the flue gas outlet with oxygen gas, or mixing all the flue gas from the flue gas outlet with oxygen gas, then introducing the obtained mixture into the firebox to be mixed with the fuel for combustion;
wherein, the non-nitrogen inert gaseous diluent is selected from one or two of CO2 gas and superheated steam.

2 more elements

A combustion system with low nitrogen oxide emission, characterized in that, the combustion system comprises a furnace, a flue gas circulation system, an oxygen gas pipeline, a fuel pipeline, and a control system;

the furnace is sequentially provided with a radiation section and a convection section;
the radiation section is provided therein with a burner;
the flue gas outlet is used for emission of flue gas after combustion;
the flue gas circulation system comprises a circulation flue gas pipeline and a circulation main pipeline;
two ends of the circulation flue gas pipeline are respectively connected to the flue gas outlet and the circulation main pipeline respectively, and are used for feeding the flue gas from the flue gas outlet, i.e. a circulation flue gas, into the circulation main pipeline, to achieve circulation of the flue gas;
the oxygen gas pipeline is connected to the circulation main pipeline or the circulation flue gas pipeline, and is used for feeding oxygen gas into the circulation main pipeline;
the circulation main pipeline is connected to an burner and is used for feeding a mixed gas of the circulation flue gas or a non-nitrogen inert gaseous diluent and oxygen gas into the firebox;
the fuel pipeline is connected to the burner, and is used for feeding a fuel into the burner;
a non-nitrogen inert gaseous diluent pipeline is further included, and the non-nitrogen inert gaseous diluent pipeline is connected to the circulation flue gas pipeline or the circulation main pipeline.

6 more elements

Dependencies are inferred from the claim text.

Method for reducing nitrogen oxide emission and combustion system

Life of this patent

Method for reducing nitrogen oxide emission and combustion system

Life of this patent

Abstract

Claims14