Application of natural gas as hydrogen flame retardant and fuel suitable for hydrogen-oxygen burner

Abstract

According to the invention, natural gas can be used as a hydrogen flame retardant, specifically, the natural gas is directly and uniformly mixed with hydrogen for use, the mixing ratio of the natural gas is comprehensively evaluated and selected from three aspects of combustion speed, heat value and combustible limit, and on the premise that the natural gas is added and the volume calorific value of the mixed gas is not reduced or increased, compared with pure hydrogen, the combustion limit of the added fuel gas is reduced by at least 20%, the combustion speed is reduced by not more than 20%, the mixing ratio of the natural gas is 2-5.2%, and the mixed gas is particularly suitable for being used as fuel of an oxyhydrogen burner; and the fuel needs to be premixed with air in advance before being used, the ratio of the fuel to the air can be changed in a wide range according to the requirement of a combustor, and then the fuel / air mixed gas is directly introduced into the oxyhydrogen combustor for combustion through flow control, so that on the premise that the unit heat value of hydrogen combustion is not reduced, the safety can be guaranteed, and the fuel is non-toxic and non-corrosive.

Description

technical field [0001] The invention belongs to the technical field of combustion and relates to hydrogen fuel and its flame-retardant technology, in particular to the use of natural gas as a hydrogen flame retardant and a fuel suitable for hydrogen-oxygen burners. Background technique [0002] Reducing carbon emissions is the main trend in the development of energy systems. Hydrogen is a carbon-free fuel and an excellent energy carrier. It can solve the volatility problems of renewable energy such as wind energy, solar energy, and water energy. It is considered to be the most promising energy in the 21st century. Promising clean fuel. Combustion is an important way to utilize hydrogen. Hydrogen has a wide range of flammable limits and a fast combustion speed, which is 7 to 8 times the laminar combustion speed of alkanes. This leads to many problems in the direct combustion of hydrogen in the burner. Burning hydrogen directly in a hydrogen gas stove is extremely prone to ba...

AI Technical Summary

Problems solved by technology

Burning hydrogen directly in a hydrogen gas stove is very easy to produce backfire

In oxyhydrogen cutting welding, the hydrogen and oxygen injected by combustion are used as heat sources to cut metals, etc., and the hydrogen combustion speed is too fast, resulting in the cutting line of the cutting welding flame becoming shorter and the cutting ability weakened; in addition, due to the wide flammability limit of hydrogen, presents a serious security risk

In order to solve the problems of safety and excessive combustion speed when using hydrogen, the commonly used flame retardants are diluent gases, such as CO 2 , N 2 etc., but mixing it into hydrogen will reduce the unit calorific value of hydrogen combustion; another commonly used flame retardant is halogenated hydrocarbon flame retardants, such as fluorine / chlorine / bromine atom halogenated hydrocarbons, etc., but Halogenated hydrocarbons and their conversion products are toxic and corrosive

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