CN212109516U

CN212109516U - Low-nitrogen heat accumulating type combustor and combustion system

Info

Publication number: CN212109516U
Application number: CN202020663735.3U
Authority: CN
Inventors: 潘涛; 郭行; 阎越宽; 徐平; 杨占春; 黄建
Original assignee: Fujian Longtao Environmental Technology Co ltd
Current assignee: Fujian Longtao Environmental Technology Co ltd
Priority date: 2020-04-27
Filing date: 2020-04-27
Publication date: 2020-12-08
Anticipated expiration: 2030-04-27

Abstract

The utility model provides a low-nitrogen heat accumulating type burner and a combustion system, wherein the burner comprises a heat accumulating chamber, a grid, an elbow, a burner block, an air smoke mixer and a fuel smoke mixer; a grid is arranged in the heat storage chamber, and a heat storage ball is arranged on the grid; one end of the regenerator is connected with one end of the elbow, and the other end of the elbow is connected with the burner block; a spray gun sleeve is arranged in the side wall of the burner block, and a fuel spray gun is arranged in the spray gun sleeve; a flue gas inlet and a flue gas outlet are formed in the spray gun sleeve; the inlet and outlet of the regenerator are used for connecting external pipelines, and the opposite ends of the connection ends of the burner block and the elbow are used for being communicated with the hearth; a ever burning torch is also arranged in the side wall of the burner block; the air smoke mixer is arranged at the bottom of the heat accumulation chamber and is used for being connected with an air smoke mixing pipeline; the fuel smoke mixer is close to the nozzle of the fuel spray gun and is fixedly arranged on the outer wall of the fuel spray gun. The utility model has the characteristics of energy-conservation and nitrogen oxide discharge are low.

Description

Low-nitrogen heat accumulating type combustor and combustion system

Technical Field

The utility model belongs to the technical field of clean burning, concretely relates to low nitrogen type heat accumulation formula combustor and combustion system.

Background

At present, a heat accumulating type burner and a combustion system matched with the heat accumulating type burner are used as relatively mature and practical energy-saving products, are commonly used for heating an aluminum smelting furnace, and can greatly save fuel consumption. When the aluminum smelting furnace is heated by using the regenerative burner and the combustion system matched with the regenerative burner, two regenerative burners are usually arranged on two sides of the aluminum smelting furnace respectively. When one heat accumulating type burner works in a burning mode, the other heat accumulating type burner is closed, meanwhile, smoke in the aluminum smelting furnace can be absorbed to the heat accumulator inside the aluminum smelting furnace, the heat accumulator is heated by the smoke, and the smoke is discharged after the temperature of the smoke is reduced to be below 200 ℃. And after the set time of the system is reached, the two heat accumulating type burners are switched in a reversing way, the originally closed heat accumulating type burners start to burn, and the originally burning heat accumulating type burners are closed, and the process is repeated in a circulating way.

Although the regenerative burner and the combustion system matched with the regenerative burner are widely applied to the aluminum smelting furnace because of the energy-saving effect of about 30 percent, the air temperature preheated by the regenerative body reaches over 800 ℃, the air and the fuel are sprayed and mixed to generate violent combustion reaction, the flame temperature is high and concentrated, the temperature gradient distribution of the flame is very obvious, and the nitrogen oxide generated by combustion is very high.

With the national and local attention on the emission of nitrogen oxides in industrial furnaces, the emission index of the nitrogen oxides is more and more severe, and therefore a low-nitrogen heat accumulating type burner is urgently needed to replace the conventional heat accumulating type aluminum smelting furnace burner.

Disclosure of Invention

In order to overcome the problems existing in the related art at least to a certain extent, the utility model provides a low-nitrogen heat accumulating type combustor and a combustion system.

According to a first aspect of embodiments of the present invention, the present invention provides a low-nitrogen heat accumulating type burner, which comprises a heat accumulating chamber, an elbow, a burner block, an air smoke mixer and a fuel smoke mixer;

a grid is arranged in the heat storage chamber, and a heat storage ball is arranged on the grid;

one end of the regenerator is connected with one end of the elbow, and the other end of the elbow is connected with the burner block;

a spray gun sleeve is arranged in the side wall of the burner block, and a fuel spray gun is arranged in the spray gun sleeve; a flue gas inlet and a flue gas outlet are formed in the spray gun sleeve; a long burning torch is arranged in the side wall of the burner block;

the inlet and the outlet of the regenerator are used for connecting an external pipeline, and the opposite ends of the connection ends of the burner block and the elbow are used for being communicated with the hearth;

the air smoke mixer is arranged in the heat storage chamber and is used for being connected with an air smoke mixing pipeline;

the fuel smoke mixer is close to the nozzle of the fuel spray gun and is fixedly arranged on the outer wall of the fuel spray gun.

In the low-nitrogen heat accumulating type burner, the air smoke mixer is of a cylinder structure with one closed end and the other open end, the open end of the cylinder structure is a smoke inlet, and a smoke mixing cavity is formed inside the cylinder structure; the side wall of one side of the cylinder structure is provided with a smoke passing hole.

Further, the smoke passing holes are uniformly formed in the side wall of the barrel structure.

In the low-nitrogen heat accumulating type combustor, the fuel smoke mixer comprises 8-12 swirl blades, and the rotation angle of each swirl blade is 15-20 degrees of clockwise rotation.

According to a second aspect of the embodiments of the present invention, the present invention further provides a low-nitrogen heat accumulating type combustion system, which comprises any one of the two low-nitrogen heat accumulating type burners, an air blower, an air regulating valve, an air reversing valve and a flue gas circulation assembly;

the two low-nitrogen heat accumulating type burners are arranged on two sides of the aluminum smelting furnace or the kiln;

the air reversing valve adopts a four-position two-way valve; the low-nitrogen heat accumulating type burner is connected with the air fan through the air reversing valve and the air regulating valve; the other low-nitrogen heat accumulating type burner is connected with a chimney through the air reversing valve;

the smoke circulating assembly is connected with the air smoke mixer and the spray gun sleeve of the two low-nitrogen heat accumulating type combustors and is used for sucking smoke generated by one low-nitrogen heat accumulating type combustor into the other low-nitrogen heat accumulating type combustor.

In the low-nitrogen heat accumulating type combustion system, the flue gas circulation assembly comprises a flue gas circulation fan, an air mixed flue pipeline and a fuel mixed flue pipeline;

the outlet of the flue gas circulating fan is connected with an air smoke mixer in the low-nitrogen heat accumulating type burner at one side of the aluminum smelting furnace or the kiln through the air smoke mixing pipeline at the outlet side of the flue gas circulating fan, and is connected with a flue gas inlet and a flue gas outlet on the spray gun sleeve in the low-nitrogen heat accumulating type burner at one side of the aluminum smelting furnace or the kiln through the fuel smoke mixing pipeline at the outlet side of the flue gas circulating fan;

the inlet of the flue gas circulating fan is connected with an air smoke mixer in the low-nitrogen heat accumulating type burner at the other side of the aluminum smelting furnace or the kiln through the air smoke mixing pipeline at the inlet side of the flue gas circulating fan, and is connected with a flue gas inlet and a flue gas outlet on the spray gun sleeve in the low-nitrogen heat accumulating type burner at the other side of the aluminum smelting furnace or the kiln through the fuel smoke mixing pipeline at the inlet side of the flue gas circulating fan.

Furthermore, a one-way valve is arranged on the fuel mixing pipe connected with the smoke circulating fan.

In the above low-nitrogen heat accumulating type combustion system, the low-nitrogen heat accumulating type combustor is connected with a fuel supply assembly;

the fuel supply assembly comprises a first branch pipe, a second branch pipe and a main fuel pipe;

one end of the first branch pipeline is connected with a fuel inlet of the fuel spray gun in the low-nitrogen heat accumulating type burner at one side of the aluminum smelting furnace or the kiln, and the other end of the first branch pipeline is connected with the main fuel pipeline;

one end of the second branch pipeline is connected with a fuel inlet of the fuel spray gun in the low-nitrogen heat accumulating type burner at the other side of the aluminum smelting furnace or the kiln, and the other end of the second branch pipeline is connected with the main fuel pipeline.

Further, a first switching valve is arranged on the first branch pipeline and used for opening or closing the first branch pipeline; and a second switching valve is arranged on the second branch pipeline and is used for opening or closing the second branch pipeline.

Further, a fuel regulating valve is arranged on the main fuel pipeline and used for regulating the flow of the fuel passing through the main fuel pipeline.

According to the above embodiments of the present invention, at least the following advantages are obtained: the utility model discloses low nitrogen type heat accumulation formula combustor mixes the cigarette ware through addding air in conventional heat accumulation formula combustor and mixes the cigarette ware with fuel, can mix the air mixture in flue gas and the combustor, mixes flue gas and fuel to reduce the concentration of oxygen content and fuel in the air, make the fuel flow field more even, temperature gradient is gentler, thereby reduces nitrogen oxide's formation volume, satisfies the requirement of low nitrogen oxide emission.

The utility model discloses low nitrogen type heat accumulation formula combustion system replaces conventional heat accumulation formula combustor through utilizing low nitrogen type heat accumulation formula combustor on conventional low nitrogen type heat accumulation formula combustion system's basis, and add flue gas circulation subassembly, can fall into in the combustor of two tunnel entering burning work with some flue gas of drawing forth in the combustor of incombustible work, two tunnel flue gases mix the air mixing in the combustor of smoke ware and fuel mixed smoke ware and work through the air respectively, thereby reduce the concentration of oxygen content and fuel in the air, make the fuel flow field more even, temperature gradient is gentler, thereby reduce nitrogen oxide's formation volume, satisfy the requirement of low nitrogen oxide emission.

The embodiment of the utility model provides a low nitrogen type heat accumulation formula combustion system not only possesses the actual energy-conserving effect of conventional heat accumulation formula combustion system, possesses the characteristics that the nitrogen oxide discharges lowly moreover.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification of the invention, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic diagram of a conventional regenerative burner and a conventional combustion system in the prior art.

Fig. 2 is a second schematic diagram of a conventional regenerative burner and a conventional combustion system in the prior art.

Fig. 3 is a schematic diagram of a low-nitrogen regenerative burner and a combustion system according to an embodiment of the present invention.

Fig. 4 is a second schematic diagram of a low-nitrogen regenerative burner and a combustion system according to an embodiment of the present invention.

Fig. 5 is a schematic structural view of an air-fuel mixer in a low-nitrogen heat accumulating type burner according to an embodiment of the present invention.

Fig. 6 is a schematic view of a connection relationship between a fuel-mixing device and a fuel spray gun in a low-nitrogen heat accumulating type burner according to an embodiment of the present invention.

Description of reference numerals:

1. a conventional regenerative burner; 11. a regenerator; 12. a grid; 121. a heat storage ball; 13. bending the pipe; 14. a burner block; 15. a spray gun sleeve; 151. a flue gas inlet and outlet; 16. a fuel spray gun; 17. a ever burning torch; 18. an air-to-smoke mixer; 181. a smoke inlet; 182. a smoke mixing cavity; 183. smoke passing holes; 19. a fuel-fired soot mixer;

10. an aluminum smelting furnace;

2. an air blower;

3. an air regulating valve;

4. an air diverter valve; 41. a first end of an air diverter valve; 42. a second end of the air diverter valve; 43. a third end of the air reversing valve; 44. a fourth end of the air diverter valve;

5. a chimney;

6. a first branch conduit; 61. a first switching valve;

7. a main fuel line; 71. a fuel regulating valve;

8. a second branch conduit; 81. a second switching valve;

9. a flue gas circulation assembly; 91. a flue gas circulating fan; 92. an air-mixed smoke pipeline; 93. a fuel smoke mixing pipeline; 931. a one-way valve.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the spirit of the present invention will be described in detail with reference to the accompanying drawings, and any person skilled in the art can change or modify the techniques taught by the present invention without departing from the spirit and scope of the present invention after understanding the embodiments of the present invention.

The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention. Additionally, the same or similar numbered elements/components used in the drawings and the embodiments are used to represent the same or similar parts.

As used herein, the terms "first," "second," …, etc. do not denote any order or sequential importance, nor are they used to limit the invention, but rather are used to distinguish one element from another or from another element or operation described in the same technical language.

With respect to directional terminology used herein, for example: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Accordingly, the directional terminology used is intended to be illustrative and is not intended to be limiting of the present teachings.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

As used herein, "and/or" includes any and all combinations of the described items.

References to "plurality" herein include "two" and "more than two"; reference to "multiple sets" herein includes "two sets" and "more than two sets".

As used herein, the terms "substantially", "about" and the like are used to modify any slight variation in quantity or error that does not alter the nature of the variation. In general, the range of slight variations or errors that such terms modify may be 20% in some embodiments, 10% in some embodiments, 5% in some embodiments, or other values. It should be understood by those skilled in the art that the aforementioned values can be adjusted according to actual needs, and are not limited thereto.

Certain words used to describe the invention are discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the invention.

The technologies capable of effectively reducing the emission of nitrogen oxides in the prior art comprise an air classification technology, a fuel classification technology, a flue gas circulation technology, a thick and thin combustion technology, a low-oxygen combustion technology and the like. The utility model discloses utilize flue gas circulation technique to solve the high problem of nitrogen oxide emission that conventional heat accumulation formula combustor 1 exists.

As shown in fig. 1, the conventional regenerative burner 1 includes a regenerative chamber 11, a grill 12, an elbow 13, burner blocks 14, a lance casing 15, a fuel lance 16, and a pilot burner 17.

A grid 12 is arranged in the heat storage chamber 11, and a heat storage ball 121 is arranged on the grid 12.

One end of the regenerator 11 is tightly connected with one end of the elbow 13 through a mounting flange, a bolt and a nut, and the joint of the regenerator 11 and the elbow 13 is sealed by a ceramic fiber felt with the thickness of 20 mm. The other end of the elbow 13 is tightly connected with the burner block 14 through a mounting flange, a bolt and a nut, and the joint of the elbow 13 and the burner block 14 is sealed by using a ceramic fiber felt with the thickness of 20 mm.

The lance sleeve 15 is fixedly arranged in the side wall of the burner block 14, and the fuel lance 16 is inserted in the lance sleeve 15 and is tightly connected with the lance sleeve 15 by a mounting flange, bolts and nuts.

The inlet and outlet of the regenerator 11 are used for connecting an external air pipeline or a flue gas pipeline, and the opposite end of the connecting end of the burner block 14 and the elbow 13 is used for communicating with the hearth of the aluminum smelting furnace 10 or other industrial furnaces.

A pilot burner 17 is fixedly disposed in the side wall of burner block 14 and is used to generate a flame to ignite the fuel from fuel gun 16.

Specifically, the pilot light ignition gun 17 may also be disposed in the side wall of the burner block 14 by means of an ignition gun sleeve. The nozzle of the pilot burner 17 is arranged symmetrically to the nozzle of the fuel lance 16 about the longitudinal center line of the burner block 14, so that the fuel sprayed from the fuel lance 16 can be ignited quickly.

The conventional regenerative combustion system includes two conventional regenerative burners 1, an air blower 2, an air regulating valve 3, and an air direction changing valve 4. The following description will specifically take an example in which a conventional regenerative combustion system is used for the aluminum smelting furnace 10.

Two conventional regenerative burners 1 are correspondingly disposed at both sides of the aluminum smelting furnace 10. The conventional regenerative burner 1 disposed at the left side of the aluminum smelting furnace 10 is a left side burner, and the conventional regenerative burner 1 disposed at the right side of the aluminum smelting furnace 10 is a right side burner.

Fig. 1 shows a state of the system when the left burner is operated without combustion and the right burner is operated without combustion.

As shown in fig. 1, the air-switching valve 4 is a four-position two-way valve that cyclically switches directions in a reciprocating manner according to a switching period preset in the entire combustion control program. Specifically, a first end 41 of the air reversing valve is connected with an inlet and an outlet of the heat storage chamber 11 in the left burner through a left pipeline, a second end 42 of the air reversing valve is connected with an inlet and an outlet of the heat storage chamber 11 in the right burner through a right pipeline, a third end 43 of the air reversing valve is connected with the air fan 2 through the air regulating valve 3, and a fourth end 44 of the air reversing valve is connected with the chimney 5. The first end 41 of the air diverter valve communicates with a third end 43 of the air diverter valve and the second end 42 of the air diverter valve communicates with a fourth end 44 of the air diverter valve.

The fuel inlet of the fuel lance 16 in the left burner is connected to the main fuel line 7 via a first branch line 6, wherein a first switching valve 61 is provided on the first branch line 6, and the first switching valve 61 is used to open or close the first branch line 6. When the first switching valve 61 is opened, the main fuel pipe 7 can supply fuel to the fuel injection lance 16 in the left burner.

The fuel inlet of the fuel lance 16 in the right burner is connected to the main fuel conduit 7 via a second branch conduit 8, wherein the second branch conduit 8 is provided with a second switching valve 81, and the second switching valve 81 is used to open or close the second branch conduit 8. With the second switching valve 81 open, the main fuel line 7 can supply fuel to the fuel lances 16 in the right burner.

The main fuel pipe 7 is further provided with a fuel regulating valve 71, and the fuel regulating valve 71 is used for regulating the flow rate of the fuel passing through the main fuel pipe 7.

Air generated by the air fan 2 enters the left pipeline through the air regulating valve 3, the third end 43 of the air reversing valve and the first end 41 of the air reversing valve, and enters the regenerator 11 of the left burner through the left pipeline. Air passes through the grid in the regenerator 11 and enters the elbow 13 through the gaps between the thermal balls 121.

The first switching valve 61 is opened and the second switching valve 81 is closed, the main fuel pipe 7 supplies fuel to the fuel lance 16 in the left burner, the left burner is operated by combustion, and the right burner is operated by non-combustion. Air enters the channel of the burner block 14 through the elbow 13, is mixed with fuel sprayed by the fuel spray gun 16, meets continuous flame generated by the ever-burning flame gun 17, and then enters the hearth of the aluminum smelting furnace 10 for combustion.

The flue gas generated by combustion enters the burner block 14 channel of the right-side combustor, flows through the elbow 13 of the right-side combustor and enters the regenerator 11 of the right-side combustor. In the regenerator 11 of the right burner, the flue gas heats the heat storage balls 121 to a temperature about 100 ℃ lower than the furnace temperature, and after passing through the grid 12, the temperature of the flue gas is reduced to below 200 ℃. The cooled flue gas is exhausted to the atmosphere through the inlet and outlet of the regenerator 11, the second end 42 of the air reversing valve, the fourth end 44 of the air reversing valve and the chimney 5 in sequence.

In the above combustion process, the combustion load is adjusted by adjusting the air control valve 3 and the fuel control valve 71.

Fig. 2 is a second schematic diagram of a conventional regenerative burner and a conventional combustion system in the prior art, which shows the system state when the left burner is not operated with combustion and the right burner is operated with combustion.

The conventional regenerative combustion system shown in fig. 2 is different from the conventional regenerative combustion system shown in fig. 1 in that: the right burner is burnt to work, and the left burner is closed; and the connection relation between the air reversing valve 4 and the left pipeline, the right pipeline, the air fan 2 and the chimney 5.

As shown in fig. 2, the connection relationship between the air reversing valve 4 and the left pipeline, the right pipeline, the air blower 2 and the chimney 5 is specifically as follows: the first end 41 of the air reversing valve is connected with the inlet and outlet of the heat storage chamber 11 in the left burner through a left pipeline, the second end 42 of the air reversing valve is connected with the inlet and outlet of the heat storage chamber 11 in the right burner through a right pipeline, the third end 43 of the air reversing valve is connected with the air fan 2 through the air regulating valve 3, and the fourth end 44 of the air reversing valve is connected with the chimney 5. The second end 42 of the air diverter valve communicates with a third end 43 of the air diverter valve and the first end 41 of the air diverter valve communicates with a fourth end 44 of the air diverter valve.

Air generated by the air fan 2 enters the right pipeline through the air regulating valve 3, the third end 43 of the air reversing valve and the second end 42 of the air reversing valve, and enters the regenerator 11 of the right burner through the right pipeline. Air passes through the grid in the regenerator 11 and enters the elbow 13 through the gaps between the thermal balls 121.

The first switching valve 61 is closed and the second switching valve 81 is opened, the main fuel pipe 7 supplies fuel to the fuel injection lance 16 in the right burner, the left burner does not burn and operates, and the right burner burns and operates. Air enters the channel of the burner block 14 through the elbow 13, is mixed with fuel sprayed by the fuel spray gun 16, meets continuous flame generated by the ever-burning flame gun 17, and then enters the hearth of the aluminum smelting furnace 10 for combustion.

The flue gas generated by combustion enters the burner block 14 channel of the left burner, flows through the elbow 13 of the left burner and enters the regenerator 11 of the left burner. In the regenerator 11 of the left burner, the flue gas heats the heat storage balls 121 to a temperature about 100 ℃ lower than the furnace temperature, and after passing through the grid 12, the temperature of the flue gas is reduced to 200 ℃ or lower. The cooled flue gas is exhausted to the atmosphere through the inlet and outlet of the regenerator 11, the first end 41 of the air reversing valve, the fourth end 44 of the air reversing valve and the chimney 5 in sequence.

In the above combustion process, the combustion load is also adjusted by adjusting the air control valve 3 and the fuel control valve 71.

Fig. 3 is a schematic diagram of a low-nitrogen regenerative burner and a combustion system according to an embodiment of the present invention. Fig. 4 is a second schematic diagram of a low-nitrogen regenerative burner and a combustion system according to an embodiment of the present invention.

As shown in fig. 3 and 4, the embodiment of the present invention provides a low-nitrogen heat accumulating type burner, which adds an air smoke mixer 18 and a fuel smoke mixer 19 on the basis of the existing conventional heat accumulating type burner 1, and a flue gas inlet and outlet 151 is provided on the lance casing 15, and the flue gas inlet and outlet 151 is used for the inlet and outlet of flue gas.

The air smoke mixer 18 is disposed in the heat storage chamber 11, and may be disposed at the bottom of the heat storage chamber 11, and the air smoke mixer 18 is used to connect the air smoke mixing pipeline 92, so as to mix the air in the heat storage chamber 11 with the flue gas.

As shown in fig. 5, the air smoke mixer 18 is of a cylindrical structure with one end closed and the other end open, the open end of the cylindrical structure is a smoke inlet 181, and a smoke mixing cavity 182 is formed inside the cylindrical structure. The side wall of one side of the cylinder structure is evenly provided with a smoke passing hole 183 so that smoke entering the smoke mixing cavity 182 from the smoke inlet 181 can evenly pass through. The smoke passing through the smoke passing holes 183 can be uniformly mixed with the air in the regenerator 11.

As shown in fig. 6, the fuel mixer 19 is a swirling device that is disposed adjacent to the nozzle tip of the fuel lance 16 and is fixedly disposed on the outer wall of the fuel lance 16.

Specifically, the fuel smoke mixer 19 comprises 8-12 swirl blades, and the rotation angle of each swirl blade is 15-20 degrees of clockwise rotation, so that a rotation effect is generated when smoke is sprayed out, and the mixing of the smoke and the fuel is further promoted.

As shown in fig. 3 and fig. 4, the embodiment of the present invention provides a low-nitrogen heat accumulating type combustion system, which is based on the existing conventional heat accumulating type combustion system, and utilizes the embodiment of the present invention to provide a low-nitrogen heat accumulating type combustion system which replaces the conventional heat accumulating type combustor in the prior art and adds the flue gas circulation component 9. The flue gas circulation assembly 9 includes a flue gas circulation fan 91, an air mixing flue duct 92, and a fuel mixing flue duct 93.

Wherein, the outlet of the flue gas circulating fan 91 is connected with the air smoke mixer 18 in the burner at one side of the aluminum smelting furnace 10 through the air smoke mixing pipeline 92 at the outlet side thereof, and is connected with the flue gas inlet and outlet 151 on the lance sleeve 15 in the burner at one side of the aluminum smelting furnace 10 through the fuel smoke mixing pipeline 93 at the outlet side thereof. The inlet of the flue gas recirculation fan 91 is connected with the air smoke mixer 18 in the burner at the other side of the aluminum smelting furnace 10 through an air smoke mixing pipeline 92 at the inlet side of the flue gas recirculation fan, and is connected with the flue gas inlet and outlet 151 on the lance casing 15 in the burner at the other side of the aluminum smelting furnace 10 through a fuel smoke mixing pipeline 93 at the inlet side of the flue gas recirculation fan.

The flue gas circulating fan 91 has a three-way reversing function, has a reversing function following the combustion system, and can change the circulating flowing direction of the flue gas.

In addition, in order to avoid the situation that the high-temperature flue gas flows backwards from the inside of the spray gun sleeve 15 under the action of the flue gas circulating fan 91, the fuel-mixed flue pipes 93 on the two sides of the flue gas circulating fan 91 are both provided with one-way valves 931 so as to prevent the situation that the fuel spray gun 16 is burnt by the high-temperature flue gas due to the backflow of the flue gas.

The following description will specifically take the example of the low-nitrogen regenerative combustion system provided by the embodiment of the present invention applied to the aluminum smelting furnace 10.

The embodiment of the utility model provides a two low nitrogen type heat accumulation formula combustors correspond the both sides that set up at aluminium smelting furnace 10. The setting is left at aluminium smelting furnace 10 the embodiment of the utility model provides a low nitrogen type regenerative burner is left side combustor, sets up on aluminium smelting furnace 10 right side the utility model provides a low nitrogen type regenerative burner is right side combustor.

Fig. 3 shows the state of the system when the left burner is operated without combustion and the right burner is operated without combustion.

As shown in fig. 3, the air-switching valve 4 is a four-position two-way valve that cyclically switches directions in a reciprocating manner according to a switching period preset in the entire combustion control program. Specifically, a first end 41 of the air reversing valve is connected with an inlet and an outlet of the heat storage chamber 11 in the left burner through a left pipeline, a second end 42 of the air reversing valve is connected with an inlet and an outlet of the heat storage chamber 11 in the right burner through a right pipeline, a third end 43 of the air reversing valve is connected with the air fan 2 through the air regulating valve 3, and a fourth end 44 of the air reversing valve is connected with the chimney 5. The first end 41 of the air diverter valve communicates with a third end 43 of the air diverter valve and the second end 42 of the air diverter valve communicates with a fourth end 44 of the air diverter valve.

The left burner and the right burner are both connected to a fuel supply assembly. Wherein the fuel supply assembly comprises a first branch conduit 6, a second branch conduit 8 and a main fuel conduit 7. The fuel provided by the fuel supply assembly can be high-calorific-value gas fuel such as liquefied gas, natural gas, coke oven gas and the like, and can also be high-calorific-value liquid fuel such as diesel oil and the like.

The inlet of the flue gas circulating fan 91 is connected with the air smoke mixer 18 in the right burner through an air smoke mixing pipeline 92 at the inlet side thereof, and is connected with the flue gas inlet and outlet 151 on the lance sleeve 15 in the right burner through a fuel smoke mixing pipeline 93 at the inlet side thereof. The outlet of the flue gas recirculation fan 91 is connected with the air smoke mixer 18 in the left burner through an air smoke mixing pipeline 92 on the outlet side thereof, and is connected with the flue gas inlet and outlet 151 on the lance sleeve 15 in the left burner through a fuel smoke mixing pipeline 93 on the outlet side thereof.

The check valve 931 on the fuel smoke mixing pipe 93 connected to the left burner is opened, and the check valve 931 on the fuel smoke mixing pipe 93 connected to the right burner is closed.

The flue gas generated by combustion enters the burner block 14 channel of the right-side combustor, flows through the elbow 13 of the right-side combustor and enters the regenerator 11 of the right-side combustor. In the regenerator 11 of the right burner, the flue gas heats the heat storage balls 121 to a temperature about 100 ℃ lower than the furnace temperature, and after passing through the grid 12, the temperature of the flue gas is reduced to below 200 ℃.

The cooled flue gas is divided into two parts and is led out from the regenerator 11. A part of the cooled flue gas is discharged into the atmosphere through an inlet and an outlet of the regenerator 11, a second end 42 of the air reversing valve, a fourth end 44 of the air reversing valve and the chimney 5 in sequence; the other part of the cooled flue gas enters the flue gas circulating fan 91 through the air smoke mixer 18 in the right burner and the right air smoke mixing pipeline 92 in turn; at this time, the flue gas recirculation fan 91 is switched to draw flue gas from the right burner to the left burner.

The flue gas sucked by the flue gas circulating fan 91 is divided into two paths. One path of flue gas sequentially passes through the left air smoke mixing pipeline 92 and the air smoke mixer 18 in the left burner to be mixed with the air in the regenerator 11, and the flue gas and the air are mixed and then enter the burner block 14; the other path of flue gas passes through the left fuel mixing pipe 93 and the flue gas inlet and outlet 151 on the spray gun sleeve 15 in the left burner in sequence, enters the spray gun sleeve 15, generates rotational flow through the fuel mixing device 19 and is mixed with the fuel sprayed by the fuel spray gun 16 to be sprayed. And the air and the fuel mixed with the flue gas are ignited by the ever burning torch 17 and enter the hearth of the aluminum smelting furnace 10 for burning.

Fig. 4 shows the system state when the left burner is operated without combustion and the right burner is operated with combustion.

The regenerative low-nitrogen combustion system shown in fig. 4 is different from the regenerative low-nitrogen combustion system shown in fig. 3 in that: the right burner is burnt to work, and the left burner is closed; the connection relation between the air reversing valve 4 and the left pipeline, the right pipeline, the air fan 2 and the chimney 5 is realized; and the direction in which the flue gas recirculation fan 91 draws flue gas.

As shown in fig. 4, the connection relationship between the air reversing valve 4 and the left pipeline, the right pipeline, the air blower 2 and the chimney 5 is specifically as follows: the first end 41 of the air reversing valve is connected with the inlet and outlet of the heat storage chamber 11 in the left burner through a left pipeline, the second end 42 of the air reversing valve is connected with the inlet and outlet of the heat storage chamber 11 in the right burner through a right pipeline, the third end 43 of the air reversing valve is connected with the air fan 2 through the air regulating valve 3, and the fourth end 44 of the air reversing valve is connected with the chimney 5. The second end 42 of the air diverter valve communicates with a third end 43 of the air diverter valve and the first end 41 of the air diverter valve communicates with a fourth end 44 of the air diverter valve.

The first switching valve 61 is closed and the second switching valve 81 is opened, the main fuel pipe 7 supplies fuel to the fuel injection lance 16 in the right burner, the left burner does not burn and operates, and the right burner burns and operates. The check valve 931 on the fuel smoke mixing pipe 93 connected to the right burner is opened, and the check valve 931 on the fuel smoke mixing pipe 93 connected to the left burner is closed.

The first switching valve 61 is closed and the second switching valve 81 is opened, the main fuel pipe 7 supplies fuel to the fuel lance 16 in the right burner, the right burner is operated by combustion, and the left burner is operated by non-combustion. Air enters the channel of the burner block 14 through the elbow 13, is mixed with fuel sprayed by the fuel spray gun 16, meets continuous flame generated by the ever-burning flame gun 17, and then enters the hearth of the aluminum smelting furnace 10 for combustion.

The flue gas generated by combustion enters the burner block 14 channel of the left burner, flows through the elbow 13 of the left burner and enters the regenerator 11 of the left burner. In the regenerator 11 of the left burner, the flue gas heats the heat storage balls 121 to a temperature about 100 ℃ lower than the furnace temperature, and after passing through the grid 12, the temperature of the flue gas is reduced to 200 ℃ or lower.

The cooled flue gas is divided into two parts and is led out from the regenerator 11. The first end 41 and the fourth end of the air reversing valve are communicated, and a part of cooled flue gas is discharged into the atmosphere through the inlet and the outlet of the regenerator 11, the first end 41 of the air reversing valve, the fourth end 44 of the air reversing valve and the chimney 5 in sequence; the other part of the cooled flue gas enters the flue gas circulating fan 91 through the air smoke mixer 18 in the left burner and the left air smoke mixing pipeline 92 in sequence; at this time, the flue gas recirculation fan 91 is switched from the left burner to the right burner.

The flue gas sucked by the flue gas circulating fan 91 is divided into two paths. One path of flue gas sequentially passes through the right air flue gas mixing pipeline 92 and the air flue gas mixer 18 in the right burner to be mixed with the air in the regenerator 11, and the flue gas and the air are mixed and then enter the burner block 14; the other path of flue gas passes through the right fuel mixing pipe 93 and the flue gas inlet and outlet 151 on the spray gun sleeve 15 in the right burner in sequence, enters the spray gun sleeve 15, generates rotational flow through the fuel mixing device 19 and is mixed with the fuel sprayed by the fuel spray gun 16 to be sprayed. And the air and the fuel mixed with the flue gas are ignited by the ever burning torch 17 and enter the hearth of the aluminum smelting furnace 10 for burning.

The embodiment of the utility model provides a low nitrogen type heat accumulation formula combustion system adopts the flue gas circulation principle, in some flue gas of drawing forth falls into two tunnel entering combustion work's combustors in the combustor of incombustible work, two tunnel flue gases mix the air mixing in the combustor of cigarette ware 19 and work through air mixing cigarette ware 18 and fuel respectively, thereby reduce the oxygen content in the air and the concentration of fuel, make the fuel flow field more even, temperature gradient is gentler, thereby reduce nitrogen oxide's formation volume, satisfy the requirement of low nitrogen oxide emission. The embodiment of the utility model provides a low nitrogen type heat accumulation formula combustion system not only possesses the actual energy-conserving effect of conventional heat accumulation formula combustor 1, possesses the characteristics that the nitrogen oxide discharges lowly moreover.

The foregoing is only an illustrative embodiment of the present invention, and any equivalent changes and modifications made by those skilled in the art without departing from the spirit and principles of the present invention should fall within the protection scope of the present invention.

Claims

1. A low-nitrogen heat accumulating type burner is characterized by comprising a heat accumulating chamber, an elbow, a burner block, an air smoke mixer and a fuel smoke mixer;

2. A low-nitrogen regenerative burner as claimed in claim 1, wherein the air-smoke mixer is a tubular structure with one end closed and the other end open, the open end of the tubular structure is a smoke inlet, and a smoke mixing chamber is formed inside the tubular structure; the side wall of one side of the cylinder structure is provided with a smoke passing hole.

3. A low nitrogen type regenerative burner as claimed in claim 2, wherein said smoke passing holes are uniformly formed on the side wall of said cylindrical structure.

4. The low-nitrogen heat accumulating type burner as claimed in claim 1, wherein the fuel-smoke mixer comprises 8 to 12 swirl vanes, and the rotation angle of each swirl vane is 15 to 20 degrees clockwise.

5. A low-nitrogen heat accumulating type combustion system is characterized by comprising two low-nitrogen heat accumulating type combustors, an air fan, an air regulating valve, an air reversing valve and a flue gas circulating assembly, wherein the two low-nitrogen heat accumulating type combustors are as claimed in any one of claims 1 to 4;

6. The low-nitrogen regenerative combustion system as claimed in claim 5, wherein the flue gas circulation assembly includes a flue gas circulation fan, an air mixed flue gas pipeline and a fuel mixed flue gas pipeline;

7. The low-nitrogen heat accumulating type combustion system as claimed in claim 6, wherein a check valve is provided on the fuel mixing pipe connected to the flue gas circulating fan.

8. The regenerative low-nitrogen combustion system as claimed in claim 5, wherein a fuel supply unit is connected to the regenerative low-nitrogen burner;

9. A low-nitrogen regenerative combustion system as claimed in claim 8, wherein a first switching valve is provided on the first branch duct, the first switching valve being for opening or closing the first branch duct; and a second switching valve is arranged on the second branch pipeline and is used for opening or closing the second branch pipeline.

10. The low-nitrogen regenerative combustion system as claimed in claim 8, wherein a fuel regulating valve is disposed on the main fuel pipe for regulating the flow of fuel passing through the main fuel pipe.