Combustion device of multi-fuel heating furnace with extremely low heat value

Abstract

The utility model discloses a combustion device of an ultra-low calorific value multi-fuel heating furnace. Key links are a high calorific value fuel gas shunting module, an inner layer rotational flow assembly-divergent nozzle-spherical nozzle structure and an acceleration section-outer layer rotational flow assembly structure of an outer layer channel. The high-calorific-value fuel gas distribution module adjusts the calorific value of premixed fuel gas in the outer layer channel, and it is guaranteed that the calorific value reaches the burner design value after different low-calorific-value fuel gas is mixed with high-calorific-value fuel gas A stable high-temperature heat source is provided for the combustion device through the structure of the inner-layer rotational flow assembly, the divergent nozzle and the spherical nozzle, and stable operation of the combustor is guaranteed. The accelerating section-outer layer rotational flow assembly structure ensures that premixed fuel gas and air are fully mixed, so that the low-heating-value fuel gas is quickly and stably combusted. According to the utility model, the stable combustion of extremely low calorific value gas can be realized, the fuel adaptability is good, and the enterprise operation cost can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of heating furnace combustion devices, in particular to an extremely low calorific value multi-fuel heating furnace combustion device. Background Art

[0002] Chemical heating furnaces use gas fuel combustion to provide heat. In order to reduce the operating costs of enterprises, the fuel is generally by-product gas generated in chemical production. Chemical by-product gas is affected by raw materials and processes, and the combustible components and calorific value fluctuate greatly. For chemical by-product gases with extremely low calorific values ​​(combustible components less than 5%), they cannot be burned directly and need to be mixed with a certain proportion of high calorific value by-product gases. Although the calorific value of the gas is improved, there are still problems such as unstable combustion and poor adaptation during the combustion process. In order to improve the stability of combustion, chemical by-product gases with extremely low calorific values ​​need to be mixed with a large proportion of high calorific value by-product gases, that is, a large amount of high calorific value high-quality gas is provided, which increases the operating costs of enterprises. This is mainly because many chemical by-product gases can still be used as raw materials for other chemical production. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a combustion device for an extremely low calorific value multi-fuel heating furnace, which can achieve stable combustion of extremely low calorific value gas and has good fuel adaptability, and can effectively reduce the operating costs of enterprises.

[0004] The extremely low calorific value multi-fuel heating furnace combustion device according to the embodiment of the utility model comprises:

[0005] A layer tube assembly, the layer tube assembly comprises an inner layer tube, a middle layer tube, an outer layer tube and a lateral diverter tube; the inner layer tube, the middle layer tube and the outer layer tube are arranged in sequence from the inside to the outside, the inner side of the inner layer tube is a central channel, a middle layer channel is formed between the middle layer tube and the inner layer tube, and an outer layer channel is formed between the outer layer tube and the middle layer tube; the inlet end of the central channel, the inlet end of the middle layer channel and the inlet end of the outer layer channel are all located at one end of the layer tube assembly and are respectively used to pass high calorific value gas, air and extremely low calorific value gas; the lateral diverter tube is connected between the inner layer tube and the middle layer tube, and is used to divert a part of the high calorific value gas in the central channel to the outer layer channel for premixing with the extremely low calorific value gas in the outer layer channel; the outer layer channel has an acceleration section, and the acceleration section is located downstream of the connection between the lateral diverter tube and the middle layer tube;

[0006] An air splitter, one end of the air splitter is inserted into the outlet end of the middle-layer channel, and the other end of the air splitter extends out of the outlet end of the middle-layer channel; an inner-layer air outlet is formed between the air splitter and the inner-layer tube; an outer-layer air outlet is formed between the air splitter and the middle-layer tube, and the outer-layer air outlet extends to the inner side of the middle-layer channel and is located downstream of the acceleration section; an annular nozzle is formed between the air splitter and the outer-layer tube, and the inner side of the other end of the air splitter includes a gradually diverging nozzle connected to the inner-layer air outlet, and the end face of the gradually diverging nozzle is flush with the end face of the annular nozzle;

[0007] a spherical nozzle connected to the outlet end of the central passage and located in the divergent nozzle;

[0008] An inner layer swirl assembly, the inner layer swirl assembly being arranged in the inner layer air outlet;

[0009] An outer swirl assembly, the outer swirl assembly being disposed between the air splitter and the outer tube and located downstream of the air outer layer outlet;

[0010] An ignition gun is used to ignite the high calorific value fuel gas in the gradually divergent nozzle.

[0011] The working principle of the extremely low calorific value multi-fuel heating furnace combustion device of the utility model embodiment is as follows: high calorific value gas, air and extremely low calorific value gas are respectively introduced into the central channel, the middle channel and the outer channel from the inlet end of the central channel, the inlet end of the middle channel and the inlet end of the outer channel, wherein a part of the high calorific value gas in the central channel enters the outer channel through the lateral diverter pipe, and is premixed with the extremely low calorific value gas in the outer channel to form premixed gas, and another part of the high calorific value gas channel flows along the central channel to the spherical nozzle, and is ejected from the spherical nozzle to the gradually expanding nozzle; the air in the middle channel is split into two parts through the air diverter, one part of the air is the outer layer air, and the other part of the high calorific value gas channel flows along the central channel to the spherical nozzle, and is ejected from the spherical nozzle to the gradually expanding nozzle; the air in the middle channel is split into two parts through the air diverter, one part of the air is the outer layer air, and the other part of the air is the outer layer air. The outlet flows to the high-speed negative pressure area of ​​the outer channel, and the other part of the air is the inner layer air, which is swirled into the gradually diverging nozzle through the inner layer air outlet and under the action of the inner layer swirl component, mixed with the swirl of the high calorific value gas ejected from the spherical nozzle and then burned, so that the flame rotates and sprays out, ignites the mixture of premixed gas and air ejected from the annular nozzle, and forms a swirl negative pressure area in the center of the gradually diverging nozzle, sucks in high-temperature flue gas, and improves combustion stability; the premixed gas in the outer channel is accelerated by the acceleration section, and is premixed with the air flowing into the outer channel from the outer layer air outlet, and is swirled out from the annular nozzle under the action of the outer layer swirl component, and is ignited by the flame that rotates outward at the gradually diverging nozzle, so that the premixed gas burns fully and stably.

[0012] The key links of the extremely low calorific value multi-fuel heating furnace combustion device of the embodiment of the utility model are: high calorific value gas diversion module, inner layer swirl component-gradually divergent nozzle-spherical nozzle structure and outer layer channel acceleration section-outer layer swirl component structure. The high calorific value gas diversion module adjusts the calorific value of the premixed gas in the outer layer channel to ensure that the calorific value of different low calorific value gases mixed with high calorific value gases reaches the burner design value. The inner layer swirl component-gradually divergent nozzle-spherical nozzle structure provides a stable high-temperature heat source for the combustion device to ensure stable operation of the burner. The acceleration section-outer layer swirl component structure ensures the full mixing of the premixed gas and air, so that the low calorific value gas burns quickly and stably.

[0013] The advantage of the extremely low calorific value multi-fuel heating furnace combustion device of the embodiment of the utility model is that it can achieve efficient combustion of different extremely low calorific value gases, while reducing the use of high calorific value high-quality gases, thereby reducing the operating costs of the enterprise. The center adopts an inner layer swirl component-gradually expanding nozzle-spherical nozzle combination design, which not only provides a high-temperature heat source for the outer circle gas, but also achieves stable combustion. The outer layer adopts an acceleration section-outer layer swirl component structure to achieve premixing of premixed gas and air swirl, which can achieve rapid and full combustion of premixed gas, shorten the combustion time, and improve the fuel burnout rate. By adjusting the high calorific value gas diversion module, changing the high calorific value gas diversion ratio, and changing the calorific value of the premixed gas in the outer channel, the fuel adaptability of the combustion device is improved.

[0014] In some embodiments, the inner tube includes a first straight tube section and an adjustable throttling tube section, the inlet end of the lateral diverter tube is connected to the first straight tube section, and the adjustable throttling tube section is connected between the first straight tube section and the spherical nozzle.

[0015] In some embodiments, the adjustable throttling pipe section includes a convergent pipe section, a second straight pipe section and a gradually expanding pipe section connected in sequence, the convergent pipe section is connected to the first straight pipe section, the throat flow area of ​​the convergent pipe section is adjusted by replacing the throttling plate, the inner diameter and outer diameter of the second straight pipe section are smaller than the inner diameter and outer diameter of the first straight pipe section, and the outlet end of the gradually expanding pipe section is connected to the spherical nozzle.

[0016] In some embodiments, there are multiple lateral diverter tubes, the inlet ends of the multiple lateral diverter tubes are evenly distributed on the first straight pipe section, and the outlet ends of the multiple lateral diverter tubes are evenly distributed on the middle-layer tube.

[0017] In some embodiments, the middle tube includes a third straight tube section and an accelerating tube section located downstream of the third straight tube section, the accelerating tube section includes a gradually expanding outer peripheral surface, and the accelerating section is formed between the gradually expanding outer peripheral surface and the outer tube.

[0018] In some embodiments, the annular nozzle includes a straight ring portion and a tapered ring portion which are axially connected, and the straight ring portion is located between the outlet end of the air outer layer outlet and the tapered ring portion.

[0019] In some embodiments, the inner swirl assembly includes a plurality of inner swirl blades, which are evenly distributed circumferentially; the outer swirl assembly includes a plurality of outer swirl blades, which are evenly distributed circumferentially.

[0020] In some embodiments, a flame monitoring module is further included. The flame monitoring module is installed in the outer channel and is used to monitor whether there is flame at the gradually divergent nozzle and the annular nozzle.

[0021] In some embodiments, the ignition gun is disposed in the middle channel.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 It is a cross-sectional schematic diagram of a combustion device of an extremely low calorific value multi-fuel heating furnace according to an embodiment of the utility model;

[0025] Figure 2 for Figure 1 Enlarged schematic diagram at point A in the middle.

[0026] Reference numerals:

[0027] Inner tube 1; first straight tube section 11; adjustable throttling tube section 12; zoom-in tube section 121; second straight tube section 122; gradually expanding tube section 123; middle tube 2; third straight tube section 21; acceleration tube section 22; gradually expanding outer peripheral surface 221; outer tube 3; lateral diverter tube 4; air diverter 5; gradually expanding nozzle 501; spherical nozzle 6; inner swirl assembly 7; outer swirl assembly 8; flame monitoring module 9; ignition gun 10; central channel 100; middle channel 200; inner air outlet 201; outer air outlet 202; outer channel 300; acceleration section 301; annular nozzle 302; straight ring portion 3021; ​​gradually contracting ring portion 3022. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] Combine the following Figure 1 to Figure 2 To describe the extremely low calorific value multi-fuel heating furnace combustion device of the embodiment of the utility model.

[0030] like Figure 1 and Figure 2 As shown, the extremely low calorific value multi-fuel heating furnace combustion device according to the embodiment of the utility model includes a layer tube assembly, an air diverter 5, a spherical nozzle 6, an inner layer swirl assembly 7, an outer layer swirl assembly 8 and an ignition gun 9.

[0031] Specifically, the layer tube assembly includes an inner layer tube 1, a middle layer tube 2, an outer layer tube 3 and a lateral diverter tube 4. The inner layer tube 1, the middle layer tube 2 and the outer layer tube 3 are arranged in sequence from the inside to the outside, the inner side of the inner layer tube 1 is a central channel 100, a middle layer channel 200 is formed between the middle layer tube 2 and the inner layer tube 1, and an outer layer channel 300 is formed between the outer layer tube 3 and the middle layer tube 2; the inlet end of the central channel 100, the inlet end of the middle layer channel 200 and the inlet end of the outer layer channel 300 are all located at one end of the layer tube assembly and are respectively used to pass high calorific value gas, air and extremely low calorific value gas, so that the high calorific value gas, air and extremely low calorific value gas are transported to the other end of the layer tube assembly through the central channel 100, the middle layer channel 200 and the outer layer channel 300 respectively. The lateral diverter pipe 4 is connected between the inner layer pipe 1 and the middle layer pipe 2, the inlet end of the lateral diverter pipe 4 is welded to the inner layer pipe 1, and the outlet end of the lateral diverter pipe 4 is welded to the middle layer pipe 2. The lateral diverter pipe 4 is used to divert a part of the high calorific value gas in the central channel 100 to the outer channel 300, and premix it with the extremely low calorific value gas in the outer channel 300; that is, the inner layer pipe 1 and the lateral diverter pipe 4 constitute a high calorific value gas diversion module, and the high calorific value gas enters the inner layer pipe 1, that is, the central channel 100, from the inlet end of the central channel 100. When it reaches the inlet end of the lateral diverter pipe 4, a part of the high calorific value gas is diverted to the outer channel 300. The high calorific value gas flows through the outer channel 300 through the lateral diversion pipe 4, and is fully premixed with the extremely low calorific value gas in the outer channel 300 to form a premixed gas and flow to the outlet end of the outer channel 300, and the other part of the high calorific value gas continues to flow along the central channel 100 to the outlet end of the central channel 100; the outer channel 300 has an acceleration section 301, and the acceleration section 301 is located downstream of the connection between the lateral diversion pipe 4 and the middle tube 2, so that the acceleration section 301 can accelerate the premixed gas, and generate a high-speed negative pressure at the downstream end of the acceleration section 301, that is, the outlet end of the outer channel 300, to inject air. In addition, it should be noted that by adjusting the high calorific value gas diversion module, changing the high calorific value gas diversion ratio, and changing the calorific value of the premixed gas in the outer channel 300, the fuel adaptability of the combustion device can be improved.

[0032] The air splitter 5 is arranged at the other end of the layer tube assembly. One end of the air splitter 5 is inserted in the outlet end of the middle layer channel 200, and the other end of the air splitter 5 extends out of the outlet end of the middle layer channel 200. An inner layer air outlet 201 is formed between the air splitter 5 and the inner layer tube 1; an outer layer air outlet 202 is formed between the air splitter 5 and the middle layer tube 2, and the outer layer air outlet 202 extends to the inner side of the middle layer channel 200 and is located downstream of the acceleration section 301; an annular nozzle 302 is formed between the air splitter 5 and the outer layer tube 3, and the inner side of the other end of the air splitter 5 includes a gradually expanding nozzle 501 connected to the inner layer air outlet 201, and the end face of the gradually expanding nozzle 501 is flush with the end face of the annular nozzle 302. It can be understood that by setting the air splitter 5, the outlet of the middle channel 200 is divided into an outer air outlet 202 and an inner air outlet 201. In this way, the air enters the middle channel 200 from the inlet end of the middle channel 200. When reaching one end of the air splitter 5, a part of the air enters the outer channel 300 through the outer air outlet 202 and mixes with the premixed gas accelerated by the acceleration section 301. Since the outlet end of the outer air outlet 202 is located in the high-speed negative pressure area downstream of the acceleration section 301, the air can be ejected. The premixed gas and air can be ejected from the annular nozzle 302 at a high speed, while the other part of the air quickly enters the gradually expanding nozzle 501 through the inner air outlet 201. It should be noted that the distribution ratio of the inner air at the inner air outlet 201 and the air at the outer air outlet 202 can be changed by adjusting the diameter of one end of the air splitter 5.

[0033] The spherical nozzle 6 is connected to the outlet end of the central channel 100 and is located in the gradually diverging nozzle 501, so that a negative pressure zone can be formed in the center.

[0034] The inner swirl assembly 7 is arranged in the inner air outlet 201; by arranging the inner swirl assembly 7, the air swirl can be fully mixed with the high calorific value gas ejected from the spherical nozzle 6, forming a swirl negative pressure zone at the center of the gradually expanding nozzle 501, sucking in high-temperature flue gas, and improving combustion stability.

[0035] The outer swirl assembly 8 is arranged between the air splitter 5 and the outer tube 3, and is located downstream of the air outer layer outlet 202. By arranging the outer swirl assembly 8, the premixed gas can be premixed with the air swirl, and the premixed gas can be quickly and fully burned, the combustion time can be shortened, and the burnout rate of the mixed fuel can be improved.

[0036] The ignition gun 9 is used to ignite the high calorific value gas in the gradually diverging nozzle 501.

[0037] The working principle of the extremely low calorific value multi-fuel heating furnace combustion device of the utility model embodiment is: high calorific value gas, air and extremely low calorific value gas are respectively introduced into the central channel 100, the middle channel 200 and the outer channel 300 from the inlet end of the central channel 100, the inlet end of the middle channel 200 and the inlet end of the outer channel 300, wherein a part of the high calorific value gas in the central channel 100 enters the outer channel 300 through the lateral diverter pipe 4, and is premixed with the extremely low calorific value gas in the outer channel 300 to form a premixed gas, and the other part of the high calorific value gas channel flows along the central channel 100 to the spherical nozzle 6, and is ejected from the spherical nozzle 6 to the gradually expanding nozzle 501; the air in the middle channel 200 is divided into two parts through the air diverter 5, one part of the air is the outer layer air, and the outer layer air passes through the outer layer air. The outlet 202 flows to the high-speed negative pressure area of ​​the outer channel 300, and the other part of the air is the inner layer air, which is swirl-jetted into the gradually diverging nozzle 501 through the inner layer air outlet 201 and under the action of the inner layer swirl component 7, and is mixed with the swirl of the high calorific value gas ejected from the spherical nozzle 6 and then burned, so that the flame rotates and sprays outward, ignites the mixture of premixed gas and air ejected from the annular nozzle 302, and forms a swirl negative pressure area in the center of the gradually diverging nozzle 501, sucking in high-temperature flue gas and improving combustion stability; the premixed gas in the outer channel 300 is accelerated by the acceleration section 301, and is premixed with the air flowing into the outer channel 300 from the outer layer air outlet 202, and is swirl-jetted from the annular nozzle 302 under the action of the outer layer swirl component 8, and is ignited by the flame that rotates and sprays outward at the gradually diverging nozzle 501, so that the premixed gas burns fully and stably.

[0038] The key links of the extremely low calorific value multi-fuel heating furnace combustion device of the embodiment of the utility model are: high calorific value gas diversion module, inner layer swirl component 7-gradually divergent nozzle 501-spherical nozzle 6 structure and outer layer channel 300 acceleration section 301-outer layer swirl component 8 structure. The high calorific value gas diversion module adjusts the calorific value of the premixed gas in the outer layer channel 300 to ensure that the calorific value of different low calorific value gases mixed with high calorific value gases reaches the burner design value. The inner layer swirl component 7-gradually divergent nozzle 501-spherical nozzle 6 structure provides a stable high-temperature heat source for the combustion device to ensure the stable operation of the burner. The acceleration section 301-outer layer swirl component 8 structure ensures the full mixing of the premixed gas and air, so that the low calorific value gas burns quickly and stably.

[0039] The advantage of the extremely low calorific value multi-fuel heating furnace combustion device of the embodiment of the utility model is that it can achieve efficient combustion of different extremely low calorific value gases, while reducing the use of high calorific value high-quality gases, thereby reducing the operating costs of the enterprise. The center adopts the inner layer swirl component 7-gradually expanding nozzle 501-spherical nozzle 6 combined design, which not only provides a high-temperature heat source for the outer circle gas, but also achieves stable combustion. The outer layer adopts the acceleration section 301-outer layer swirl component 8 structure to achieve premixing of premixed gas and air swirl, which can achieve rapid and full combustion of premixed gas, shorten the combustion time, and improve the fuel burnout rate. By adjusting the high calorific value gas diversion module, changing the high calorific value gas diversion ratio, and changing the calorific value of the premixed gas in the outer channel 300, the fuel adaptability of the combustion device is improved.

[0040] In some implementations, the calorific value of the premixed gas after the extremely low calorific value gas and the high calorific value gas in the outer channel 300 are premixed is not less than 1500 kJ / Nm 3 , to meet the design requirements of full combustion of the premixed gas using the extremely low calorific value multi-fuel heating furnace combustion device of this embodiment, thereby improving the fuel adaptability of the combustion device.

[0041] In some embodiments, the velocity of the premixed gas and air in the outer channel 300 is not less than 40 m / s, thereby ensuring negative pressure in the downstream end area of ​​the acceleration section 301 and ejecting air.

[0042] In some embodiments, the inner tube 1 includes a first straight tube section 11 and an adjustable throttling tube section 12, the inlet end of the lateral flow dividing tube 4 is connected to the first straight tube section 11, and the adjustable throttling tube section 12 is connected between the first straight tube section 11 and the spherical nozzle 6. The distribution ratio and flow rate of the high calorific value gas in the inner tube 1 can be adjusted by the adjustable throttling tube section 12.

[0043] In some embodiments, the adjustable throttling pipe section 12 includes a convergent pipe section 121, a second straight pipe section 122 and a gradually expanding pipe section 123 connected in sequence, the convergent pipe section 121 is connected to the first straight pipe section 11, the throat flow area of ​​the convergent pipe section 121 is adjusted by replacing the throttle plate, the inner diameter and outer diameter of the second straight pipe section 122 are smaller than the inner diameter and outer diameter of the first straight pipe section 11, and the outlet end of the gradually expanding pipe section 123 is connected to the spherical nozzle 6. Among them, the function of the convergent pipe section 121 is to adjust the distribution ratio and flow rate of the high calorific value gas; the function of the gradually expanding pipe section 123 is, on the one hand, to adapt to the spherical nozzle 6, and on the other hand, to adapt to the gradually expanding nozzle 501, to ensure that the distance between the gradually expanding pipe section 123 and the root of the side wall of the gradually expanding nozzle 501, that is, the radial size of the outlet end of the air inner layer outlet 201 is appropriate, for example, gradually decreases toward the outlet direction, or keeps consistent with the radial size of the inlet end of the air inner layer outlet 201.

[0044] In some embodiments, there are multiple lateral flow divider pipes 4, the inlet ends of the multiple lateral flow divider pipes 4 are evenly distributed on the first straight pipe section 11, and the outlet ends of the multiple lateral flow divider pipes 4 are evenly distributed on the middle layer pipe 2. This is conducive to uniform mixing of high calorific value gas and very low calorific value gas.

[0045] In some embodiments, the middle tube 2 includes a third straight tube section 21 and an accelerating tube section 22 located downstream of the third straight tube section 21, the accelerating tube section 22 includes a gradually expanding outer peripheral surface 221, and an accelerating section 301 is formed between the gradually expanding outer peripheral surface 221 and the outer tube 3, and the accelerating section is used to accelerate and increase the flow rate of the premixed gas.

[0046] In some embodiments, the annular nozzle 302 includes an axially connected straight ring portion 3021 and a tapered ring portion 3022, wherein the straight ring portion 3021 is located between the outlet end of the air outer layer outlet 202 and the tapered ring portion 3022, wherein the tapered ring portion 3022 can increase the ejection speed of the mixture of premixed gas and air.

[0047] In some embodiments, the inner swirl component 7 includes a plurality of inner swirl blades, which are evenly distributed circumferentially, so that the inner air can be better swirled out; the outer swirl component 8 includes a plurality of outer swirl blades, which are evenly distributed circumferentially, so that the mixture of premixed gas and air can be better swirled out.

[0048] In some embodiments, a flame monitoring module 9 is further included. The flame monitoring module 9 is installed in the outer channel 300 through a sleeve and is used to monitor whether there is flame at the gradually divergent nozzle 501 and the annular nozzle 302.

[0049] In some embodiments, the ignition gun 10 is disposed in the middle layer pipe 2 to ignite the high calorific value gas in the gradually diverging nozzle 501 .

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A very low calorific value multi-fuel heating furnace combustion device, characterized in that: include: A layer tube assembly, the layer tube assembly comprises an inner layer tube, a middle layer tube, an outer layer tube and a lateral diverter tube; the inner layer tube, the middle layer tube and the outer layer tube are arranged in sequence from the inside to the outside, the inner side of the inner layer tube is a central channel, a middle layer channel is formed between the middle layer tube and the inner layer tube, and an outer layer channel is formed between the outer layer tube and the middle layer tube; the inlet end of the central channel, the inlet end of the middle layer channel and the inlet end of the outer layer channel are all located at one end of the layer tube assembly and are respectively used to pass high calorific value gas, air and extremely low calorific value gas; the lateral diverter tube is connected between the inner layer tube and the middle layer tube, and is used to divert a part of the high calorific value gas in the central channel to the outer layer channel for premixing with the extremely low calorific value gas in the outer layer channel; the outer layer channel has an acceleration section, and the acceleration section is located downstream of the connection between the lateral diverter tube and the middle layer tube; An air splitter, one end of the air splitter is inserted into the outlet end of the middle-layer channel, and the other end of the air splitter extends out of the outlet end of the middle-layer channel; an inner-layer air outlet is formed between the air splitter and the inner-layer tube; an outer-layer air outlet is formed between the air splitter and the middle-layer tube, and the outer-layer air outlet extends to the inner side of the middle-layer channel and is located downstream of the acceleration section; an annular nozzle is formed between the air splitter and the outer-layer tube, and the inner side of the other end of the air splitter includes a gradually diverging nozzle connected to the inner-layer air outlet, and the end face of the gradually diverging nozzle is flush with the end face of the annular nozzle; a spherical nozzle connected to the outlet end of the central passage and located in the divergent nozzle; An inner layer swirl assembly, the inner layer swirl assembly being arranged in the inner layer air outlet; An outer swirl assembly, the outer swirl assembly being disposed between the air splitter and the outer tube and located downstream of the air outer layer outlet; An ignition gun is used to ignite the high calorific value fuel gas in the gradually diverging nozzle.

2. The extremely low calorific value multi-fuel heating furnace combustion device according to claim 1 is characterized in that: The inner tube includes a first straight tube section and an adjustable throttling tube section, the inlet end of the lateral diverter tube is connected to the first straight tube section, and the adjustable throttling tube section is connected between the first straight tube section and the spherical nozzle.

3. The extremely low calorific value multi-fuel heating furnace combustion device according to claim 2 is characterized in that: The adjustable throttling pipe section includes a convergent pipe section, a second straight pipe section and a gradually expanding pipe section which are connected in sequence. The convergent pipe section is connected to the first straight pipe section. The throat flow area of ​​the convergent pipe section is adjusted by replacing the throttling plate. The inner diameter and outer diameter of the second straight pipe section are smaller than the inner diameter and outer diameter of the first straight pipe section. The outlet end of the gradually expanding pipe section is connected to the spherical nozzle.

4. The extremely low calorific value multi-fuel heating furnace combustion device according to claim 2 is characterized in that: There are multiple lateral flow-dividing pipes, the inlet ends of the multiple lateral flow-dividing pipes are evenly distributed on the first straight pipe section, and the outlet ends of the multiple lateral flow-dividing pipes are evenly distributed on the middle-layer pipe.

5. The extremely low calorific value multi-fuel heating furnace combustion device according to claim 2, characterized in that: The middle layer pipe comprises a third straight pipe section and an accelerating pipe section located downstream of the third straight pipe section, the accelerating pipe section comprises a gradually expanding outer peripheral surface, and the accelerating section is formed between the gradually expanding outer peripheral surface and the outer layer pipe.

6. The extremely low calorific value multi-fuel heating furnace combustion device according to claim 5, characterized in that: The annular nozzle comprises a straight ring portion and a tapered ring portion which are axially connected, and the straight ring portion is located between the outlet end of the air outer layer outlet and the tapered ring portion.

7. The extremely low calorific value multi-fuel heating furnace combustion device according to any one of claims 1 to 6, characterized in that: The inner swirl assembly includes a plurality of inner swirl blades, which are evenly distributed circumferentially; the outer swirl assembly includes a plurality of outer swirl blades, which are evenly distributed circumferentially.

8. The extremely low calorific value multi-fuel heating furnace combustion device according to any one of claims 1 to 6, characterized in that: It also includes a flame monitoring module, which is installed in the outer channel and is used to monitor whether there is flame at the gradually divergent nozzle and the annular nozzle.

9. The extremely low calorific value multi-fuel heating furnace combustion device according to any one of claims 1 to 6, characterized in that: The ignition gun is arranged in the middle channel.

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