RU2324111C1 - System for remote firing of torch gases - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: system for remote firing of torch gases contains the high-voltage electric discharger, pipe, where the fuel gas, e.g., natural gas, is discharged to the gas torch, pipe where the stoichiometric mixture of gases is formed and the detonation combustion occurs, which fires the natural gas, electrolyser for automatic creation of stoichiometric mixture of oxygen and hydrogen by electrolyzing the aqueous solution of alkali hydroxide, and the electrolyser is supplied with the separator to prevent electrolyte from falling into firing line.

EFFECT: method provides more reliable firing of gas torch and power inputs for creation of stoichiometric mixture of gases.

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Description

The invention relates to the field of oil and gas, petrochemical and other industries and can be used to improve the reliability of ignition of gas burners of flare plants and reduce energy consumption during thermal utilization of toxic products.

At gas and oil fields, at many large enterprises of the oil, chemical and petrochemical industries, flare installations of high-altitude and ground types are operated. They are intended for the combustion of waste gases and multiphase systems of industrial waste, which are formed in the production process.

Thermal disposal of combustible gases and toxic liquids helps prevent environmental pollution and makes it possible to efficiently operate wells and process hydrocarbon production products. In addition, flammable and flammable toxic gases and vapors are sent to the torch in emergency cases, during the period when the equipment is put into operation, when equipment is stopped for repairs and the process mode is set up.

An analysis of thermal waste gas utilization devices in flare plants shows that gas burners are ignited mainly by creating a mixture of fuel (natural gas) and air and initiating combustion of this mixture with a high-voltage electric discharge.

A prerequisite for successful ignition is the formation of a stoichiometric mixture of natural gas and air in a ratio of 1:10 and its complete combustion in the chemical reaction zone following the shock wave that occurs when this mixture is blown up by a high-voltage spark.

The ignition systems used, both domestic and foreign, have insufficient reliability and have limitations on climatic operating conditions. The main reason for these disadvantages of the known devices is the problem of the formation of a stoichiometric mixture of gases and a stable detonation wave in the ignition line.

It is known, for example, a device for igniting a torch, consisting of two pipes. One of them has a slot or holes along the entire height, the other, through which combustible gas enters, is connected at certain intervals by small tubes with a pipe with a slot. In a pipe with a slot, a combustible mixture of gas and intake air is formed. To ignite a gas burner, the mixture is ignited with an electric fuse in the lower part of the pipe (see, for example, I.I. Strizhevsky, A.I. Elnatanov. Flare units. - Moscow, Chemistry, 1979, p.184) [1]. The known device has insufficient stability and low reliability of the ignition of gas burners due to the fact that the stoichiometric mixture of fuel gas and air, necessary for the chemical reaction of combustion, is formed randomly.

The objective of the invention is the disposal of waste gases and multiphase systems of industrial wastewater through thermal exposure using flare devices.

The technical result of the invention is to increase the reliability of ignition of gas burners of flare devices while reducing energy consumption to form a stoichiometric gas mixture.

The specified technical result is achieved by the fact that the proposed device for remote ignition of flare gases, including a direct current generator, a high voltage generator, an electrolyzer for automatically creating a stoichiometric gas mixture by electrolysis of an aqueous solution of alkali metal hydroxide, equipped with an electric input, a separator to prevent electrolyte from entering the ignition line with a drain a valve in its lower part, connected to the electrolyzer with a tube for supplying a stoichiometric mixture of gases (hydrogen and oxygen) and their detonation combustion and gas pipe - with a cavity of a high-voltage electric discharge, in which a check valve and spark plug are installed, and the electric discharge is connected to the ignition line by a tube.

A diagram of the proposed device is presented in the drawing.

The device for remote ignition of flare gases includes a DC generator 1, a high voltage generator 2, an electrolyzer 3 equipped with an electric input 4, a separator 5 connected to the electrolyzer 3 by a pipe 6. A drain valve 7 is installed at the bottom of the separator 5. The separator 5 is connected by a gas pipe 8 to a high voltage an electric discharge 9, in which a check valve 10 and a candle 11 are installed. The high-voltage electric discharge 9 is connected by a tube 12 to the ignition line 13.

The device operates as follows. An electrolytic cell 3 contains an aqueous solution of an alkali metal hydroxide, for example, potassium. A current of the order of 40 A is supplied to the electrodes of the electrolyzer 3 from the DC generator 1. During the electrolysis of the solution, a stoichiometric mixture of hydrogen and oxygen is created, which through the pipe 6 enters the separator 5, from it, overcoming the resistance of the check valve 10, the gas mixture through the gas pipe 8 enters the cavity of the high voltage electric discharge 9 and through the tube 12 into the ignition line 13. When this ignition line 13 is completely filled with a mixture of hydrogen and oxygen with a high-voltage pulse from a high-voltage generator 2, a detonation combustion of this mixture is initiated by means of a candle 11, the flame of which ignites the fuel entering a gas burner through a separate pipe.

In contrast to the known devices for ignition of flare gases, in which a stoichiometric gas mixture is prepared by selecting air and natural gas consumption and, in this regard, requiring both time and significant energy consumption, the stoichiometric mixture of oxygen and hydrogen is automatically generated in the proposed device as a result of electrolysis of an aqueous alkaline hydroxide solution metals (see, for example, Brief Chemical Encyclopedia, v.4 - Moscow, Soviet Encyclopedia, 1967, p.1065).

It is known that for any stoichiometric mixture there are certain concentration limits at which a stationary detonation regime is ensured. When going beyond these limits, stable detonation is violated. In the proposed device, stable detonation of a mixture of hydrogen and oxygen takes place in the concentration range from 20 to 90%, which is three times higher than the concentration limits of stable detonation of a mixture of methane and air used in the known device [1]. The speed of the detonation wave of a mixture of hydrogen and oxygen, equal to 2800 m / s, is significantly, 1.6 times higher than the speed of the detonation wave for a mixture of methane and air (1720 m / s), which also increases the stability of the detonation of the proposed mixture due to a smaller decrease in combustion energy by heat transfer the walls of the pipe. Therefore, the use in the proposed device of a stoichiometric mixture of hydrogen and oxygen significantly increases the reliability of the ignition of gas burners. In addition, a comparison of the detonation parameters of detonating gas and the detonation of a mixture of methane and air taken in stoichiometric ratios shows that the detonation temperature of an explosive gas is almost 1.5 times higher than the detonation temperature of a mixture of methane and air (see, e.g., F.A .Baum, K.P. Stanyukovich, B.I. Shikhter, Explosion Physics, Moscow, GIFFL, 1959, pp. 240-260). It also increases the reliability of gas burner ignition.

Using as an electrolyte an aqueous solution of an alkali metal hydroxide, for example, potassium, belonging to symmetric electrolytes, in which the same number of anions and cations result from electrolytic dissociation, reduces the electrical resistance of the electrolyte, which reduces energy consumption when implementing the proposed method. In addition, the use as an electrolyte of an aqueous solution of an alkali metal hydroxide, for example potassium, congealing (at certain concentrations) at a temperature of minus 30 ° C, significantly expands the temperature range of application of the proposed method.

The device for remote ignition of flare gases has successfully passed preliminary and acceptance tests in a wide temperature range: from minus 30 to plus 28 ° C, which showed its high reliability, low energy consumption and climate stability.

A device for remote ignition of flare gases was introduced at the Zapolyarnoye OGPD of LLC Yamburggazdobycha and at the Experimental Plant of LLC TyumenNIIgiprogaz.

Claims (1)

A device for remote ignition of flare gases, including a DC generator, a high voltage generator, an electrolyzer for automatically creating a stoichiometric gas mixture by electrolysis of an aqueous solution of alkali metal hydroxide, equipped with an electric input, a separator to prevent electrolyte from entering the ignition line with a drain valve in its lower part, connected to an electrolyzer tube for supplying a stoichiometric mixture of hydrogen and oxygen gases and their detonation combustion and a gas pipe - with a cavity of a high-voltage electric discharge, in which a non-return valve and a candle are installed, and the electric discharge is connected by a tube to the ignition line.