RU222802U1 - Burner with two-channel gas manifold - Google Patents

Abstract

The utility model relates to fuel combustion units and can be used to reduce nitrogen oxide emissions. On the burner standing on the boiler or on a new burner, a two-channel gas manifold is installed (on the installed burner instead of the existing gas manifold) with two inlets, with gas outlets located on the inner wall of the manifold and gas distribution tubes leading gas nozzles into the firebox outside the embrasure, with gas inside the manifold is divided by a partition that provides gas supply from one inlet to the gas outlets, and from the other inlet to the gas distribution tubes. As a result of the introduction of the burner, gas jets flowing from gas nozzles located on the gas discharge tubes enter the space filled with flue gases, eject flue gases directly from the furnace and ensure dilution of the gas with flue gases before mixing it with the air flow and ignition. Reducing the concentration of reactants and combustion temperature ensures a reduction in NOx emissions. Mixers can be installed on gas nozzles to organize controlled ejection quality. The number, location, angle of inclination and type of burner device depend on the power of the burner, the aerodynamic characteristics of the burner air flow and the pressure of the gaseous fuel. The proposed burner ensures a reduction in nitrogen oxide emissions by 40-70% when burning gas. The advantage of the proposed utility model is the ability to reduce NOx emissions during gas combustion without changing the combustion elements of the fuel combustion plant and reducing the technical and economic characteristics of the robot. 1 salary f-ly, 1 ill.

Description

The utility model relates to fuel combustion plants and can be used to reduce nitrogen oxide (NOx) emissions.

Known gas-oil burners IGMG-6, MGMG-8; MGMG-10 intended for installation on hot water boilers (see Mechanical Engineering, Encyclopedia, editor-in-chief K.V. Frolov, Boiler installations, vol. IV-18, M., 2009, p. 226, fig. 2.4.21).

The disadvantage of the considered burner is the low environmental efficiency of fuel combustion, due to the design flaws of the burner in the method of organizing the combustion process, in which all gaseous fuel is supplied to the air.

One of the effective ways to reduce NOx emissions is the use of forced flue gas recirculation, which reduces the flame temperature and reduces the concentration of reactants that determine the formation of NOx. In this case, the most effective method is to supply flue gases into the burner channels (SU 1 101 622 A1, IPC F23D 17/00, published 07/07/1984). This method is implemented in the burner of the TGMP-204 boiler, consisting of two air supply channels (central and peripheral), equipped with tangential registers, a recirculation flue gas input channel is located on the periphery, and a fuel oil nozzle is installed in the center of the heater. The gas part of the burner consists of an annular gas manifold, a gas distribution nozzle in the form of a cone with holes and a gas supply pipe. The internal pipe of the gas manifold is the guide pipe of the steam-mechanical nozzle (Ya.P. Storozhuk. Tests of the TGMP-204 boiler of the 800 MW unit after reconstruction of the flue gas recirculation input into the furnace / Y.P. Storozhuk, D.R. Nosulko // Thermal power engineering. - 1984. - No. 5 - P. 13-15.). This burner was not able to achieve a good NOx reduction result due to design flaws in the combustion process.

To successfully suppress NOx, it is necessary that the recirculated flue gases do not ballast in the root region of the burner, but reach the active combustion zone, in which the main formation of NOx occurs. The main disadvantage of this method of organizing combustion remains the need for a system of forced supply of flue gas recirculation with a recirculation smoke exhauster.

Close to the utility model is the method for reducing NOx emissions described in the inventions: RU 2689654C2 published 2019-05-28, SU 1588987A1 published 1990-08-03, SU 1695040A1 published 1991-11-30, KR 101254928B1 published 2013-04-19 , EP 0893651A1 published 1999-01-27, US 2012/0186265A1 published 2012-07-26, WO 01|07833A1 published 2001-02-01, US 2005/0239005A1 published 2005-10-27, US 4380429 published 1998-12-07 , EP 2479491A1 published 2012-07-25, KR 20120070201A published 2012-06-29, KR 20120074868A published 2012-07-06, KR 20120082647A published 2012-07-24, KR 201300 61167A published 2013-06-10, US 5350293 published 1994 -09-27. In some cases, these inventions were developed with the aim of stabilizing the combustion regime by drawing in hot combustion products from the furnace. In these inventions, flue gas recirculation is organized by the burners themselves without additional flue gas supply systems, including a chimney system and a recirculation exhaust fan. Flue gases are ejected into the combustion zone, which ensures the combustion of diluted fuel and reduces the formation of NOx. The disadvantages of the method used in these inventions are: the complexity and high cost of the burner design, and a small amount of sucked flue gases from the furnace. Flue gases are ejected by the fuel or air flow into the burner mouth within the main air flow, combustion occurs in the air environment, which overall reduces the effectiveness of NOx suppression. The considered inventions cannot be applied to existing burners installed in a fuel combustion plant.

Closer to the utility model is a group of inventions that use the principle of intra-furnace recirculation due to the injection of gaseous fuel not into the air flow, but outside the air flow, outside the burner mouth: US 5542840A published 1996-08-06, US 6773256B2 published 2004-08 -10, RU 2426030C2 published 2011-08-10, US 5275552A published 1994-01-04, US 20080096146A1 published 2008-04-24, US 6007325A published 1999-12-28, US 7670135B1 published 201 0-03-02, US 9593847В1 published 2017-03-14, US 9593848A1 published 2015-12-10, US 20150285491A1 published 2015-10-08, US 6875008 B1 published 2005-04-05, KR 101213883B1 published 2012-12-18, WO2 014162074A1 published 2014-10- 09, US6773256 published 2004-08-10, WO2008104158A3 2008-09-04. These inventions involve patented techniques in which gaseous fuel and/or air are diluted with flue gases before they are mixed and reacted. The main condition for reliable combustion of gaseous fuel when using this technology is to maintain the temperature in the furnace of the fuel combustion plant above the ignition temperature of the fuel and the use of a stable flame stabilizer, while ignition and stabilization of combustion is ensured by special embrasures or the general temperature of the furnace. The disadvantages of these inventions are the complexity of the design, the need to use a special embrasure made of heat-resistant concrete and the impossibility of their use for existing burners installed in a fuel-burning installation.

Also close to the proposed utility model is a group of inventions in which the entire burner head (gas distribution device with an air channel) protrudes into the firebox: KR 101569455B1 published 2015-11-16, EP 1980788A1 published 2008-10-15, US 6071115A published 2000- 06-06, KR 1020170138042 published 2017-12-14, KR 101822997B1 published 2018-02-01, JP 6595089B2 published 2019-10-23, KR 102115576B1 published 2020-05-27, KR 10 2143032B1 published 2020-08-11. In this group of inventions, the ejection of flue gases is organized by gas nozzles with cylindrical nozzles located in the firebox along the outer perimeter of the burner air channel. The disadvantages of these inventions are the complexity of the design, the need to use special heat-resistant alloys for the part of the burner protruding into the furnace and the impossibility of using them to reduce NOx emissions on existing burners installed in a fuel combustion installation.

The prototype for the utility model is a hearth burner, discussed in the book: Mechanical Engineering, Encyclopedia, ch. editor K.V. Frolov, Boiler installations, vol. IV-18, M., 2009, p. 226, Fig. 2.4.21.

The main goal of the patented utility model is to reduce NOx emissions when burning gas through low-cost addition of burners without changing the combustion elements of the fuel-burning installation. The solution to the problem is achieved by installing, instead of the existing gas manifold, a new two-channel gas manifold with two inlets, with gas outlets on the inner surface of the manifold and gas distribution tubes, inside the gas manifold is divided by a partition that provides gas supply from one inlet to the gas outlets on the inner wall of the gas manifold, and from the other entrance to gas distribution tubes that lead gas nozzles into the firebox beyond the embrasure.

Mixers can be installed on gas nozzles to organize controlled ejection quality. Due to the organization of intra-furnace recirculation of flue gases, by ejecting flue gases directly from the furnace with gas jets, the gas is diluted with flue gases, which ensures a decrease in the flame temperature and the concentration of reacting substances, which leads to a decrease in the formation of NOx.

In fig. Figure 1 shows a longitudinal section of a burner with a two-channel gas manifold with gas distribution tubes.

The burner contains a burner frame 1, a two-channel gas manifold 2 with gas outlet holes 3 located on the inner wall of the manifold and gas distribution tubes 4, an axial swirler 5, a burner box 6, gas distribution tubes 4 leading gas nozzles 7 into the boiler furnace. The two-channel gas manifold 2 has two gas inlets 8 and 9. Inside the two-channel gas manifold there is a partition 10 installed that provides gas supply from the inlet 8 to the gas outlets 3, and from the inlet 9 to the gas distribution tubes.

As a result of the introduction of a useful model, a gas jet 11 ejects flue gases 12. are diluted with them, the new prepared fuel 13 reaches the air flow 14 and the combustion process occurs with lower temperatures and concentrations of reacting substances, which reduces the formation of NOx. A mixer 14 can be installed on the gas nozzles 7, which ensures mixing of the ejected flue gases and gas.

The burner is ignited when gas is supplied to inlet 8, which provides gas supply to the gas outlets 3 located on the inner wall of the manifold 2, to the gas inlet 9, which provides gas supply to the gas distribution tubes 4, the gas is supplied after the fuel-burning unit has gained power and the furnace has warmed up to sufficient temperatures for stable ignition. Next, the burner power increases due to an increase in gas flow through inlet 9 with a constant or gradually decreasing gas flow through inlet 8. At maximum burner power, the gas flow through inlet 8 can be 10% or less to ensure stabilization of ignition. At intermediate loads, the ratio of gas flow between the inlets depends on the design features of a particular furnace and is determined during the period of operational testing.

The use of a burner with a two-channel gas manifold ensures a reduction in NOx content in flue gases by 40-70% without reducing the technical and economic characteristics of the combustion plant and the construction of an external flue gas supply system.

Claims (2)

1. A burner containing a frame, a box, an axial swirler, a gas manifold, the inner wall of which forms the burner channel, characterized in that the gas manifold is made of two channels with two inlets, inside the gas manifold is divided by a partition that provides gas supply from one inlet to the gas outlets on the inner wall of the collector, and from the other entrance - to the gas distribution tubes, which lead gas nozzles into the firebox beyond the embrasure. 2. Burner according to claim 1, characterized in that the gas nozzles are equipped with mixers.