A flameless combustion furnace with combustion-assisted preheating and its operation method

Abstract

The present invention discloses a flameless combustion furnace with combustion-assisted preheating and an operation method, which relates to the technical field of combustion equipment. The flameless combustion furnace includes a furnace body, a combustion air flow distribution nozzle, and an ignition device. Inside the furnace body, there are a combustion chamber and a preheating and cooling chamber with a partition heat exchange relationship. The combustion chamber is provided with an air jet port, a fuel nozzle, and a tail gas discharge port. The fuel nozzle is provided with fuel jet holes. The air jet port and the fuel nozzle are respectively arranged on two opposite inner sides of the combustion chamber. The tail gas discharge port and the air jet port are located on the same side of the combustion chamber. The preheating and cooling chamber is provided with air holes and a first fuel hole; the combustion air flow distribution nozzle is configured to control the fuel input channel to communicate with the first fuel hole or the fuel jet hole; the ignition device is arranged in the preheating and cooling chamber. Through the design of the preheating and cooling chamber, the combustion furnace can preheat the wall surface by itself during the startup stage, providing fast and effective preparation conditions for the stable progress of flameless combustion.

Description

Technical Field

[0001] The present invention relates to the technical field of combustion equipment, and particularly relates to a flameless combustion furnace with combustion-assisted preheating and an operation method thereof. Background Art

[0002] Due to advantages such as high combustion efficiency and low pollutant emissions, flameless combustion technology is widely used in industrial production. However, traditional flameless combustion furnaces have some deficiencies: on the one hand, the start-up time is long and the preheating process is slow, which affects production efficiency; on the other hand, the protection measures for the furnace wall during the combustion process are insufficient, and it is prone to overheating and damage, shortening the service life of the combustion furnace. Summary of the Invention

[0003] The purpose of the present invention is to provide a flameless combustion furnace with combustion-assisted preheating and an operation method thereof, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0004] The technical solutions adopted to solve the above technical problems are as follows:

[0005] The present invention provides a flameless combustion furnace with combustion-assisted preheating, including:

[0006] A furnace body, internally provided with a combustion chamber and a preheating and cooling chamber having an inter-wall heat exchange relationship, the preheating and cooling chamber being wrapped outside the combustion chamber. The combustion chamber is provided with at least one air jet port, a fuel nozzle, and a tail gas discharge port. The fuel nozzle is provided with at least one fuel jet hole. The air jet port is communicated with the preheating and cooling chamber. The air jet port and the fuel nozzle are respectively arranged on two opposite inner sides of the combustion chamber. The tail gas discharge port and the air jet port are located on the same side of the combustion chamber. The preheating and cooling chamber is provided with at least one air jet hole and at least one first fuel jet hole;

[0007] A combustion gas distribution nozzle, provided with a fuel input channel, and the combustion gas distribution nozzle is configured to control the fuel input channel to be communicated with the first fuel jet hole or the fuel jet hole;

[0008] An ignition device, arranged in the preheating and cooling chamber.

[0009] The beneficial effects of the flameless combustion furnace of the present invention are:

[0010] During the cold start of the flameless combustion furnace, the fuel input channel is controlled by the combustion air distribution nozzle to communicate with the first fuel injection hole, so that the fuel enters the preheating and cooling chamber. At the same time, air is sprayed into the preheating and cooling chamber through the air injection hole, so that the fuel and air are mixed in the preheating and cooling chamber. Then, the fuel in the preheating and cooling chamber is ignited by the ignition device, and the generated heat is used to preheat the wall of the combustion chamber. At this time, the combustion exhaust gas is discharged outwards through the air jet port, the combustion chamber and the exhaust gas discharge port in sequence. When the wall of the combustion chamber is heated to the target temperature of flameless combustion, the fuel input channel is controlled by the combustion air distribution nozzle to communicate with the fuel jet hole, and the fuel is sprayed into the combustion chamber through the fuel jet hole by the fuel nozzle. Air is sprayed into the preheating and cooling chamber through the air injection hole and then enters the combustion chamber through the air jet port, so that the fuel and air are mixed by counterflow combustion in the combustion chamber to quickly start the flameless combustion furnace. At this time, only air is introduced into the preheating and cooling chamber. The air flows through the preheated wall, absorbs heat and then sprays into the combustion chamber, playing a role in protecting the wall of the combustion chamber and preventing it from being directly impacted by the high-temperature flame, realizing the function of cooling the wall. At the same time, the air in the preheating and cooling chamber returns the absorbed heat to the combustion chamber, improving the utilization rate of heat, maintaining the high-temperature environment in the combustion chamber and ensuring the continuous progress of flameless combustion. Through the design of the preheating and cooling chamber, the combustion furnace can preheat the wall by itself during the start-up stage without additional preheating equipment or energy input, simplifying the system structure, improving the preheating efficiency, shortening the preheating time and providing fast and effective preparation conditions for the stable progress of flameless combustion.

[0011] During the flameless combustion stage, air is sprayed into the combustion chamber through the air jet port and mixed with the fuel sprayed out by the fuel nozzle to form a uniform combustion flow field. The air jet port and the exhaust gas discharge port are located on the same side of the combustion chamber, and the exhaust gas is in the opposite direction to the high-velocity air jet direction, which increases the residence time of the combustion air flow. The air is first fully mixed with the combustion exhaust gas, and after the oxygen concentration is reduced, it is mixed with the fuel, effectively reducing the combustion rate and better maintaining the flameless combustion state. The fuel nozzle is located on the other side of the combustion chamber and can effectively mix with the air on the other side of the combustion chamber.

[0012] As a further improvement of the above technical solution, the combustion air distribution nozzle includes a nozzle seat and a fuel input pipe. The nozzle seat is provided on the furnace wall of the furnace body. The nozzle seat is provided with a rotating channel connected to the fuel nozzle. One end of the fuel input pipe is rotatably installed in the rotating channel. The fuel input channel is formed inside the fuel input pipe. One end of the fuel input pipe is provided with a fuel inlet, and at least one third fuel injection hole is eccentrically provided at the other end. One end of the fuel nozzle connected to the rotating channel is eccentrically provided with at least one fourth fuel injection hole. The fourth fuel injection hole is communicated with the fuel jet hole. At least one first fuel injection hole is provided on the outer peripheral wall of the rotating channel. At least one second fuel injection hole is provided on the outer peripheral wall of the fuel input pipe. The first fuel injection hole and the second fuel injection hole are located at the same axial position. The fuel input pipe is configured to control the on-off between the first fuel injection hole and the second fuel injection hole and the on-off between the third fuel injection hole and the fourth fuel injection hole by rotation.

[0013] As a further improvement of the above technical solution, a first split baffle is provided at one end of the fuel nozzle connected to the rotating channel. The fourth fuel injection hole is provided on the first split baffle. A second split baffle is provided at one end of the fuel input pipe close to the fuel nozzle. The third fuel injection hole is provided on the second split baffle.

[0014] As a further improvement of the above technical solution, a first rotation limiting portion is provided at the central position of the first split baffle, and a second rotation limiting portion is provided at the central position of the second split baffle. The second rotation limiting portion is rotationally connected and matched with the first rotation limiting portion.

[0015] As a further improvement of the above technical solution, a plurality of first fuel injection holes and a plurality of second fuel injection holes are respectively provided. The plurality of first fuel injection holes are annularly spaced on the outer peripheral wall of the rotating channel, and the plurality of second fuel injection holes are annularly spaced on the outer peripheral wall of the fuel input pipe.

[0016] As a further improvement of the above technical solution, the nozzle seat is provided with an air pre-supply chamber. The air pre-supply chamber wraps around the center line outside the fuel input pipe. A plurality of air injection holes are provided. The plurality of air injection holes are annularly spaced on the outer peripheral wall of the nozzle seat and communicated with the air pre-supply chamber. The air pre-supply chamber is provided with an air inlet.

[0017] As a further improvement of the above technical solution, the preheating and cooling chamber includes an ignition chamber, a catalytic chamber, and a confluence injection chamber that are connected in sequence. The ignition chamber and the confluence injection chamber are respectively located at both ends of the combustion chamber. The catalytic chamber is located on the outer peripheral side of the combustion chamber. The air injection holes and the first fuel injection holes are respectively connected to the ignition chamber. The air jet port is connected to the confluence injection chamber. The ignition device is arranged in the ignition chamber. The catalytic chamber is provided with a plurality of heat-conducting fins extending from the ignition chamber to the confluence injection chamber. The plurality of heat-conducting fins are arranged at annular intervals. The heat-conducting fins are connected to the outer peripheral wall of the combustion chamber and the inner peripheral wall of the catalytic chamber. The surface of the heat-conducting fins is provided with a catalytic combustion catalyst.

[0018] As a further improvement of the above technical solution, the fuel nozzle and the tail gas discharge port are located on the center line of the combustion chamber. There are a plurality of air jet ports. The plurality of air jet ports are arranged at annular intervals on the side of the inner end of the tail gas discharge port. The jet direction of the air jet ports is arranged along the inner wall of the combustion chamber. One end of the combustion chamber close to the tail gas discharge port is provided with a diversion inclined surface. There are a plurality of fuel jet holes. The plurality of fuel jet holes are distributed on the outer peripheral wall of the fuel nozzle.

[0019] As a further improvement of the above technical solution, the ignition device is provided with a spark plug firing part and a spark plug terminal. The spark plug firing part is arranged outside the furnace body. The spark plug terminal is arranged in the ignition chamber. The distance between the spark plug terminal and the wall surface of the ignition chamber is between 3 mm and 10 mm.

[0020] In addition, the present invention also proposes an operation method, which is applicable to the flameless combustion furnace described above. The operation method includes:

[0021] Controlling the fuel input channel to communicate with the first fuel injection hole;

[0022] Feeding fuel into the preheating and cooling chamber, and spraying air into the preheating and cooling chamber through the air injection holes, so that the fuel and air are mixed in the preheating and cooling chamber;

[0023] Igniting and burning the fuel in the preheating and cooling chamber through the ignition device to heat the combustion chamber;

[0024] When the wall of the combustion chamber reaches a preset temperature, controlling the fuel input channel to communicate with the fuel jet hole;

[0025] The fuel is injected into the combustion chamber through the fuel injection orifices, and at the same time, air is injected into the preheating and cooling chamber through the air orifices, and then enters the combustion chamber through the air jet ports, so that the fuel and air are mixed and burned to start the flameless combustion furnace.

[0026] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. Brief Description of the Drawings

[0027] The present invention will be further described below in conjunction with the drawings and embodiments;

[0028] Figure 1 It is a cross-sectional view of a flameless combustion furnace provided by the present invention, showing an embodiment;

[0029] Figure 2 It is a schematic diagram of a combustion gas distribution nozzle provided by the present invention, showing an embodiment;

[0030] Figure 3 It is a schematic diagram of a fuel nozzle provided by the present invention, showing an embodiment;

[0031] Figure 4 It is a schematic diagram of a fuel input pipeline provided by the present invention, showing an embodiment;

[0032] Figure 5 It is a control flowchart of an operation method provided by the present invention, showing an embodiment;

[0033] Reference Numerals in the Drawings:

[0034] Furnace body 100; Combustion chamber 110; Air jet port 111; Fuel nozzle 112; Fuel injection orifice 1121; Fourth fuel orifice 1122; First split baffle 1123; First rotation limit portion 1124; Tail gas discharge port 113; Preheating and cooling chamber 120; Air orifice 121; First fuel orifice 122; Ignition chamber 123; Catalytic chamber 124; Confluence injection chamber 125; Heat conduction fins 126;

[0035] Combustion gas distribution nozzle 200; Fuel input channel 210; Nozzle seat 220; Rotation channel 221; Air pre-supply chamber 222; Upper rotation sleeve 223; Air inlet 2221; Fuel input pipeline 230; Fuel inlet 231; Third fuel orifice 232; Second fuel orifice 233; Second split baffle 234; Second rotation limit portion 235; Control handle 236; Lower rotation sleeve 237;

[0036] Ignition device 300; Spark plug firing portion 310; Spark plug terminal 320. Detailed Description of the Embodiments

[0037] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0038] In the description of the present invention, it should be understood that with respect to the orientation description, such as up, down, etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0039] In the description of the present invention, "a plurality of" refers to more than two. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0040] In the description of the present invention, unless otherwise clearly defined, terms such as "arrangement", "installation", "connection", etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0042] As Figures 1 to 4 shown, a flameless combustion furnace with combustion-assisted preheating according to the present invention includes: a furnace body 100, a combustion gas flow distribution nozzle 200, and an ignition device 300.

[0043] As Figure 1 shown, a combustion chamber 110 and a preheating and cooling chamber 120 with an inter-wall heat exchange relationship are provided inside the furnace body 100. The preheating and cooling chamber 120 is wrapped outside the combustion chamber 110. It can be understood that the furnace body 100 of this embodiment includes an inner wall body and an outer wall body. The combustion chamber 110 is formed inside the inner wall body, and the preheating and cooling chamber 120 is formed between the inner wall body and the outer wall body. The furnace body 100 of this embodiment is vertically arranged, and the outer shape of the furnace body 100 is cylindrical. The center line of the furnace body 100 extends in the up and down direction. In some other embodiments, the furnace body 100 can be of other shapes, and the furnace body 100 can be horizontally arranged or extend in other directions.

[0044] As Figure 1As shown in the figure, the combustion chamber 110 is provided with at least one air jet port 111, a fuel spray head 112, and an exhaust gas discharge port 113. The fuel spray head 112 is provided with at least one fuel jet hole 1121 communicating with the combustion chamber 110. The air jet port 111 communicates with the preheating and cooling chamber 120. The air jet port 111 connects the preheating and cooling chamber 120 and the combustion chamber 110. The air jet port 111 and the fuel spray head 112 are respectively arranged on two opposite inner sides of the combustion chamber 110. In this embodiment, the air jet port 111 is arranged on the upper side of the combustion chamber 110, while the fuel spray head 112 is arranged on the lower side of the combustion chamber 110. And the exhaust gas discharge port 113 and the air jet port 111 are located on the same side of the combustion chamber 110, that is, the exhaust gas discharge port 113 is also arranged on the upper side of the combustion chamber 110. The preheating and cooling chamber 120 is provided with at least one air jet hole 121 and at least one first fuel jet hole 122. The air jet hole 121 is used to spray external air into the preheating and cooling chamber 120, while the first fuel jet hole 122 is used to spray external fuel into the preheating and cooling chamber 120.

[0045] The combustion air distribution nozzle 200 of the present invention is provided with a fuel input channel 210. The fuel input channel 210 is used to connect with an external fuel supply system to achieve fuel input. The combustion air distribution nozzle 200 is configured to control the fuel input channel 210 to communicate with the first fuel jet hole 122 or the fuel jet hole 1121. It can be understood that the fuel input channel 210 can be individually switched to communicate with the first fuel jet hole 122. At this time, the fuel in the fuel input channel 210 is sprayed into the preheating and cooling chamber 120 through the first fuel jet hole 122, or the fuel input channel 210 can be switched to communicate with the fuel jet hole 1121. At this time, the fuel in the fuel input channel 210 is sprayed into the combustion chamber 110 through the fuel jet hole 1121.

[0046] The ignition device 300 of this embodiment is arranged in the preheating and cooling chamber 120. The ignition device 300 is used to ignite the mixture of fuel and air in the preheating and cooling chamber 120.

[0047] During the cold start of the flameless combustion furnace, the fuel input passage 210 is controlled by the combustion air distribution nozzle 200 to communicate with the first fuel injection hole 122, so that fuel is introduced into the preheating and cooling chamber 120. At the same time, air is injected into the preheating and cooling chamber 120 through the air injection hole 121, so that the fuel and air are mixed in the preheating and cooling chamber 120. Then, the fuel in the preheating and cooling chamber 120 is ignited by the ignition device 300, and the generated heat is used to preheat the wall surface of the combustion chamber 110. At this time, the combustion exhaust gas sequentially passes through the air jet port 111, the combustion chamber 110 and the exhaust gas discharge port 113 and is discharged outward. When the wall surface of the combustion chamber 110 is heated to the target temperature of flameless combustion, the fuel input passage 210 is controlled by the combustion air distribution nozzle 200 to communicate with the fuel jet hole 1121, and the fuel is sprayed into the combustion chamber 110 through the fuel injection nozzle 112 via the fuel jet hole 1121. Air is sprayed into the preheating and cooling chamber 120 through the air injection hole 121 and then enters the combustion chamber 110 through the air jet port 111, so that the fuel and air are mixed in a counterflow manner in the combustion chamber 110 to quickly start the flameless combustion furnace. At this time, only air is introduced into the preheating and cooling chamber 120. The air flows through the preheated wall surface, absorbs heat and is then sprayed into the combustion chamber 110, playing a role in protecting the wall surface of the combustion chamber 110 and preventing it from being directly impacted by the high-temperature flame, thus realizing the function of cooling the wall surface. At the same time, the air in the preheating and cooling chamber 120 returns the absorbed heat to the combustion chamber 110, improving the utilization rate of heat, maintaining the high-temperature environment in the combustion chamber 110, and ensuring the continuous progress of flameless combustion. Through the design of the preheating and cooling chamber 120 of the present invention, the combustion furnace can preheat the wall surface by itself during the start-up stage without additional preheating equipment or energy input, simplifies the system structure, improves the preheating efficiency, shortens the preheating time, and provides fast and effective preparation conditions for the stable progress of flameless combustion.

[0048] During the flameless combustion stage, air is sprayed into the combustion chamber 110 through the air jet port 111 and mixed with the fuel sprayed out by the fuel injection nozzle 112 to form a uniform combustion flow field. The air jet port 111 and the exhaust gas discharge port 113 are located on the same side of the combustion chamber 110, and the exhaust gas is in the opposite direction to the high-velocity air jet direction, which increases the residence time of the combustion air flow. The air is first fully mixed with the combustion exhaust gas, and after the oxygen concentration is reduced, it is mixed with the fuel, effectively reducing the combustion rate and better maintaining the flameless combustion state. The fuel injection nozzle 112 is located on the other side of the combustion chamber 110 and can effectively mix with the air on the other side of the combustion chamber 110.

[0049] In some other embodiments, the combustion air distribution nozzle 200 can be implemented by two control valves to realize the switching of fuel delivery, that is, a control valve is provided between the fuel input passage 210 and the first fuel injection hole 122, and a control valve is provided between the fuel input passage 210 and the fuel jet hole 1121. The switching of fuel delivery is realized by controlling the on-off of the two control valves.

[0050] In order to achieve flexible switching of the gas path of the combustion furnace at different combustion stages and facilitate operation in this embodiment, such as Figure 1 and Figure 2 shown, the combustion gas flow distribution nozzle 200 includes a nozzle seat 220 and a fuel input pipe 230. The nozzle seat 220 is arranged between the inner wall body and the outer wall body of the furnace body 100 and is located at the lower side of the furnace body 100. The nozzle seat 220 is provided with a rotating channel 221 connected to the fuel nozzle 112. The rotating channel 221 of this embodiment is arranged vertically. The upper end of the rotating channel 221 is connected to the fuel nozzle 112. In some other embodiments, the rotating channel 221 can extend in other directions.

[0051] The fuel input pipe 230 is also arranged vertically. In some other embodiments, the fuel input pipe 230 can extend in other directions. The upper end of the fuel input pipe 230 is rotatably installed in the rotating channel 221. The fuel input channel 210 is formed inside the fuel input pipe 230. The lower end of the fuel input pipe 230 is provided with a fuel inlet 231. As Figure 4 shown, at least one third fuel injection hole 232 is eccentrically arranged at the upper end of the fuel input pipe 230. As Figure 3 shown, at least one fourth fuel injection hole 1122 is eccentrically arranged at one end of the fuel nozzle 112 connected to the rotating channel 221. The fourth fuel injection hole 1122 is communicated with the fuel jet hole 1121. By rotating the fuel input pipe 230, the third fuel injection hole 232 coincides or is misaligned with the fourth fuel injection hole 1122 to realize the on-off of the fuel input channel 210 and the fuel jet hole 1121.

[0052] As Figure 2 shown, the first fuel injection hole 122 of this embodiment is arranged on the outer peripheral wall of the rotating channel 221. At least one second fuel injection hole 233 is arranged on the outer peripheral wall of the fuel input pipe 230. The first fuel injection hole 122 and the second fuel injection hole 233 are located at the same axial position. By rotating the fuel input pipe 230, the second fuel injection hole 233 coincides or is misaligned with the first fuel injection hole 122 to realize the on-off of the fuel input channel 210 and the first fuel injection hole 122.

[0053] Furthermore, in this embodiment, the on-off between the first fuel injection hole 122 and the second fuel injection hole 233 and the on-off between the third fuel injection hole 232 and the fourth fuel injection hole 1122 can be controlled by rotating the fuel input pipe 230. The operation is simple and only requires rotating the fuel input pipe 230.

[0054] Furthermore, as Figure 3 and Figure 4As shown, a first split baffle 1123 is provided at the lower end of the fuel nozzle 112 of this embodiment, and a second split baffle 234 is provided at the upper end of the fuel input pipe 230. The second split baffle 234 and the first split baffle 1123 are hermetically fitted. A plurality of fourth fuel injection holes 1122 and a plurality of third fuel injection holes 232 are respectively provided. The plurality of fourth fuel injection holes 1122 are annularly spaced on the first split baffle 1123, and the plurality of third fuel injection holes 232 are annularly spaced on the second split baffle 234.

[0055] The design of the first split baffle 1123 and the second split baffle 234 enables the fuel to be split, and can precisely control the amount of fuel entering the combustion chamber 110 according to different combustion requirements, ensuring the stability and efficiency of combustion.

[0056] A first rotation limiting portion 1124 is provided at the central position of the first split baffle 1123, and a second rotation limiting portion 235 is provided at the central position of the second split baffle 234. The second rotation limiting portion 235 is rotationally connected and cooperated with the first rotation limiting portion 1124. The first rotation limiting portion 1124 and the second rotation limiting portion 235 are respectively a limiting protrusion and a limiting hole structure, so that the first split baffle 1123 and the second split baffle 234 will not shift during rotation, ensuring safety, and also forming an effective connection between the fuel nozzle 112 and the fuel input pipe 230, enabling precise control of the fuel flow.

[0057] In addition, a plurality of first fuel injection holes 122 and a plurality of second fuel injection holes 233 are respectively provided in this embodiment. The plurality of first fuel injection holes 122 are annularly spaced on the outer peripheral wall of the rotation channel 221, and the plurality of second fuel injection holes 233 are annularly spaced on the outer peripheral wall of the fuel input pipe 230 to increase the amount of fuel entering the preheating and cooling chamber 120. Among them, the second fuel injection holes 233 and the third fuel injection holes 232 are axially offset. When the second fuel injection holes 233 coincide with the first fuel injection holes 122, the third fuel injection holes 232 are offset from the fourth fuel injection holes 1122.

[0058] The plurality of first fuel injection holes 122 can enable the fuel to be sprayed from the center to the periphery into the preheating and cooling chamber 120.

[0059] Such as Figure 2As shown, the nozzle seat 220 of this embodiment further has an air pre-supply chamber 222. The air pre-supply chamber 222 wraps around the center line and is located outside the fuel input pipe 230. There are multiple air injection holes 121, and the multiple air injection holes 121 are arranged at intervals in a ring on the outer peripheral wall of the nozzle seat 220 and communicate with the air pre-supply chamber 222. The air pre-supply chamber 222 is provided with an air inlet 2221. The air pre-supply chamber 222 can enable air to be evenly sprayed into the preheating and cooling chamber 120 through the multiple air injection holes 121. In the preheating stage and the flameless combustion stage, air enters the air pre-supply chamber 222 through the air inlet 2221 and then enters the preheating and cooling chamber 120 through the multiple air injection holes 121.

[0060] And the multiple air injection holes 121 can enable air to be sprayed from the center to the surroundings into the preheating and cooling chamber 120.

[0061] On the outer peripheral wall of the lower end of the fuel input pipe 230 of this embodiment, there is a control handle 236. The fuel input pipe 230 is driven to rotate through the control handle 236. By rotating the control handle 236 in different directions, the opening and closing states between the first split baffle 1123 and the second split baffle 234 can be controlled, so as to realize the connection and closing between the third fuel injection hole 232 and the fourth fuel injection hole 1122, and the connection and closing between the second fuel injection hole 233 and the first fuel injection hole 122. This design makes the distribution of fuel more flexible, can accurately control the fuel supply flow path according to different combustion stages, and ensures the stability and efficiency of combustion.

[0062] To improve the rotation stability of the fuel input pipe 230, the air pre-supply chamber 222 of this embodiment is provided with an upper rotating collar 223, and the fuel input pipe 230 is provided with a lower rotating collar 237. The upper rotating collar 223 is rotationally connected to the lower rotating collar 237. This connection method of the rotating collar enables the air pre-supply chamber 222 and the fuel input pipe 230 to rotate flexibly, facilitating the direct rotation of the fuel input pipe 230 by rotating the control handle 236.

[0063] Furthermore, as Figure 1As shown in the figure, the preheating and cooling chamber 120 of this embodiment includes an ignition chamber 123, a catalytic chamber 124, and a confluence injection chamber 125 that are connected in sequence. The confluence injection chamber 125 and the ignition chamber 123 are respectively located at the upper and lower ends of the combustion chamber 110, and the catalytic chamber 124 is located on the outer peripheral side of the combustion chamber 110. A plurality of air injection holes 121 and a plurality of first fuel injection holes 122 are respectively connected to the ignition chamber 123, and the air jet port 111 is connected to the confluence injection chamber 125. The ignition device 300 is arranged in the ignition chamber 123. During the preheating stage, fuel enters the fuel input pipeline 230 through the fuel inlet 231, and then enters the ignition chamber through the first fuel injection hole 122. Air enters the air pre-supply chamber 222 through the air inlet 2221, and then enters the ignition chamber through the air injection hole 121. The two are evenly mixed in the ignition chamber and ignited by the ignition device 300 for preheating combustion. Then it flows into the catalytic chamber 124 to preheat the outer peripheral wall of the combustion chamber 110, and then flows into the confluence injection chamber 125 and enters the combustion chamber 110 through the air jet port 111. The combustion exhaust gas enters the combustion chamber 110 through the air jet port 111. On the one hand, it heats the inner wall, and on the other hand, it provides a large amount of combustion exhaust gas for the combustion chamber 110, creating an environment for flameless combustion. During the flameless combustion stage, air is preheated in sequence through the ignition chamber 123, the catalytic chamber 124, and the confluence injection chamber 125 to cool the inner wall. The air carrying heat is sprayed into the combustion chamber 110 again through the air jet port 111, which not only cools the wall surface but also makes full use of the cooling air to avoid waste.

[0064] In the catalytic chamber 124 of this embodiment, a plurality of heat-conducting fins 126 extending from the ignition chamber 123 to the confluence injection chamber 125 are provided. The plurality of heat-conducting fins 126 are arranged at intervals in a ring shape. The heat-conducting fins 126 are connected to the outer peripheral wall of the combustion chamber 110 and the inner peripheral wall of the catalytic chamber 124. The surface of the heat-conducting fins 126 is provided with a catalytic combustion catalyst. The heat-conducting fins 126 can, on the one hand, improve the overall structural strength of the furnace body 100, and on the other hand, increase the heat exchange area, improve the heating efficiency during the preheating stage and the cooling effect during the flameless combustion stage. The catalytic combustion catalyst reduces the combustion temperature of the fuel, enables the fuel to burn fully at a lower temperature, improves the combustion efficiency, reduces the generation of unburned residues, rapidly increases the furnace wall temperature, greatly shortens the time required for the combustion chamber 110 to reach the starting temperature, enables the combustion furnace to quickly enter the flameless combustion state, and at the same time controls the combustion temperature.

[0065] As Figure 1As shown, the fuel nozzle 112 and the exhaust gas outlet 113 of this embodiment are located on the center line of the combustion chamber 110. There are multiple air jet ports 111, and the multiple air jet ports 111 are arranged at intervals in a ring on the outer side of the inner end of the exhaust gas outlet 113. The jet direction of the air jet ports 111 is arranged along the inner wall of the combustion chamber 110. A guiding inclined surface is provided at the upper part of the combustion chamber 110. There are multiple fuel jet holes 1121, and the multiple fuel jet holes 1121 are distributed on the outer peripheral wall of the fuel nozzle 112. During use, fuel is injected into the combustion chamber 110 from the lower side through the fuel nozzle 112, and air is injected into the combustion chamber 110 from the upper side along the inner wall surface through the air jet ports 111. The air flows along the wall surface, and the air is input to the lower side of the combustion chamber 110, and is mixed with the fuel ejected from the multiple fuel jet holes 1121 on the lower side to form a uniform combustion flow field. The exhaust gas is located on the upper side of the combustion chamber 110, and the exhaust direction is upward, which is opposite to the direction of the high-speed air jet. This increases the residence time of the combustion airflow. The air jet ports 111 are arranged circumferentially along the center line of the exhaust gas outlet 113, so that the air jets uniformly along the inner wall surface and is distributed to the outside of the combustion chamber 110. At this time, the high-concentration oxygen is far away from the fuel nozzle 112 located at the center of the lower side. The air is first fully mixed with the combustion exhaust gas, and after the oxygen concentration is reduced, it is mixed with the fuel, effectively reducing the combustion rate and better maintaining the flameless combustion state. The fuel nozzle 112 is located on the lower side of the combustion chamber 110, which can effectively mix with the air at the bottom of the combustion chamber 110. The inner wall wraps the combustion chamber 110, so that the combustion airflow forms an air mass, further increasing the residence time of the combustion airflow and stabilizing the flameless combustion.

[0066] The ignition device 300 of this embodiment uses a spark plug. During the operation of the combustion furnace, the structural design and installation position of the spark plug have an important impact on the ignition effect and combustion stability.

[0067] The ignition device 300 of this embodiment is provided with a spark plug firing part 310 and a spark plug terminal 320. The spark plug firing part 310 is arranged on the outside of the furnace body 100, and the spark plug terminal 320 is arranged in the ignition chamber 123, so that the spark plug can effectively generate sparks inside the ignition chamber to ignite the mixture of fuel and air. The distance between the spark plug terminal 320 and the wall surface of the ignition chamber 123 is between 3 mm and 10 mm. This distance range can ensure that the sparks generated by the spark plug have sufficient energy, and at the same time avoid ignition failure or incomplete combustion caused by too close or too far distance.

[0068] In addition, the present invention also proposes an operation method, which is applicable to the above-mentioned flameless combustion furnace, as Figure 5 As shown, the operation method of this embodiment includes:

[0069] Step S100: Control the fuel input channel 210 to communicate with the first fuel hole 122;

[0070] Step S200: Feed fuel into the preheating and cooling chamber 120, and inject air into the preheating and cooling chamber 120 through the air injection holes 121, so that the fuel and air are mixed in the preheating and cooling chamber 120;

[0071] Step S300: Ignite and burn the fuel in the preheating and cooling chamber 120 through the ignition device 300 to heat the combustion chamber 110;

[0072] Step S400: After the wall of the combustion chamber 110 reaches the preset temperature, control the fuel input channel 210 to communicate with the fuel injection holes 1121;

[0073] Step S500: Inject fuel into the combustion chamber 110 through the fuel injection holes 1121, and at the same time inject air into the preheating and cooling chamber 120 through the air injection holes 121, and then enter the combustion chamber 110 through the air jet ports 111, so that the fuel and air are mixed and burned to start the flameless combustion furnace.

[0074] In step S100, during the ignition and preheating stage, drive the rotating fuel input pipe 230 to rotate by rotating the control handle 236, so that the second fuel injection hole 233 coincides with the first fuel injection hole 122, so as to realize the communication between the fuel input channel 210 and the first fuel injection hole 122.

[0075] In steps S200 and S300, the fuel enters the fuel input pipe 230 through the fuel inlet 231, and then enters the ignition chamber through the first fuel injection hole 122. The air enters the air pre-supply chamber 222 through the air inlet 2221, and then enters the ignition chamber through the air injection holes 121. The two are evenly mixed in the ignition chamber, and are ignited by the ignition device 300 for preheating combustion, and then flow into the catalytic chamber 124 to preheat the outer peripheral wall of the combustion chamber 110, and then flow into the confluence and injection chamber 125, and enter the combustion chamber 110 through the air jet ports 111. The combustion exhaust gas enters the combustion chamber 110 through the air jet ports 111. On the one hand, it heats the inner wall, and on the other hand, it provides a large amount of combustion exhaust gas for the combustion chamber 110 to create an environment for flameless combustion.

[0076] In steps S400 and S500, drive the rotating fuel input pipe 230 to rotate by rotating the control handle 236, so that the third fuel injection hole 232 coincides with the fourth fuel injection hole 1122, so as to realize the communication between the fuel input channel 210 and the fuel injection holes 1121. The fuel is injected into the combustion chamber 110 through the fuel injection holes 1121 through the fuel nozzle 112. The air is injected into the preheating and cooling chamber 120 through the air injection holes 121, and then enters the combustion chamber 110 through the air jet ports 111, so that the fuel and air are mixed and burned to start the flameless combustion furnace.

[0077] During the operation of the combustion furnace, through the above control method, rapid startup and stable combustion of the combustion furnace can be achieved. Under cold startup conditions, by igniting the ignition chamber, catalytic combustion is used to heat the inner wall provided with heat-conducting fins 126 and coated with catalytic combustion catalyst, and the target temperature of flameless combustion can be quickly reached, shortening the startup time. By rotating the control handle 236, the first fuel injection hole 122 is closed, the fourth fuel injection hole 1122 is opened, fuel is sprayed into the combustion chamber 110 through the fuel injection nozzle 112 via the fuel jet hole 1121, air is sprayed into the preheating and cooling chamber 120 through the air injection hole 121, and then enters the combustion chamber 110 through the air jet port 111, enabling the air to effectively control the wall temperature and return the absorbed heat to the combustion chamber 110 again, effectively starting the flameless combustion furnace.

[0078] The flameless combustion furnace of this embodiment can be applied to the following places:

[0079] Vehicle-mounted small burner: The present invention is applicable to a flameless burner with catalytic combustion-assisted preheating for vehicle-mounted environments. It is small in size and easy to install in the dedicated equipment compartment of the vehicle. Made of lightweight high-temperature resistant materials, the outer wall has good heat insulation performance to ensure that the vehicle interior will not be damaged due to the operation of the burner. The preheating and cooling chamber 120 is adjacent to the combustion chamber 110, internally equipped with an appropriate amount of heat-conducting fins 126, and coated with an efficient catalytic combustion catalyst to accelerate the preheating process and maintain a stable combustion temperature. The combustion air distribution nozzle 200 integrates an automated control system, which can intelligently adjust the mixing ratio of fuel and air according to the vehicle operating conditions and external environmental conditions.

[0080] This vehicle-mounted small burner can provide a stable heat source during vehicle driving, such as heating for vehicle-mounted decomposition equipment or heating inside the vehicle. Compared with traditional vehicle-mounted heating equipment, its startup time is shortened by about 25%, the combustion efficiency is increased by 20%, and due to the use of flameless combustion technology, it operates more quietly, with less vibration, and will not interfere with vehicle electronic devices, significantly improving the comfort and safety of use.

[0081] Industrial furnace burner: Through the synergistic effect of the preheating and cooling chamber 120 and the inner wall, the present invention effectively reduces the demand for high-temperature resistant materials. The preheating and cooling chamber 120 uses catalytic combustion to quickly heat the inner wall during the ignition stage, and at the same time, cools the inner wall by air flowing through it during the combustion stage, reducing the direct impact of high temperature on the inner wall and extending the service life. This design enables the inner wall to use materials with lower costs instead of relying on expensive high-temperature resistant alloys. In addition, due to the design of the preheating and cooling chamber 120, the service life of the furnace is extended, and due to more uniform and stable combustion, the product quality will be significantly improved.

[0082] Waste incinerator: The present invention is applicable to the application in waste incinerators. Its equipment structure includes a relatively large combustion chamber 110 and a preheating and cooling chamber 120 with a comparable volume. The inner wall of the combustion chamber 110 is made of ordinary heat-resistant steel, and the outer wall is made of heat-insulating material. Heat-conducting fins 126 are provided inside the preheating and cooling chamber 120 and coated with a catalyst. The combustion gas distribution nozzle 200 adopts an automated control system to adapt to the fluctuations in the fuel composition and flow rate during the waste incineration process. Through the special design of the preheating and cooling chamber 120 and the inner wall, the present invention utilizes the air flowing through the inner wall to achieve cooling, reducing the demand for expensive high-temperature-resistant materials. Using ordinary heat-resistant steel for the inner wall can meet the usage requirements, reducing the manufacturing cost of the equipment. At the same time, the automated control system can adjust the combustion conditions in real time according to the actual situation during the waste incineration process, improving the combustion efficiency and environmental protection performance.

[0083] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. 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, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0084] The embodiments of the present invention have been described in detail above with reference to the drawings, but the present invention is not limited to the above embodiments. Various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the relevant art.

Claims

1. A flameless combustion furnace with combustion-assisted preheating, characterized in that, Comprising: A furnace body, which is internally provided with a combustion chamber and a preheating and cooling chamber having an inter-wall heat exchange relationship. The preheating and cooling chamber is wrapped outside the combustion chamber. The combustion chamber is provided with at least one air jet port, a fuel nozzle, and an exhaust gas discharge port. The fuel nozzle is provided with at least one fuel jet hole. The air jet port communicates with the preheating and cooling chamber. The air jet port and the fuel nozzle are respectively arranged on two opposite inner sides of the combustion chamber. The exhaust gas discharge port and the air jet port are located on the same side of the combustion chamber. The preheating and cooling chamber is provided with at least one air hole and at least one first fuel hole; A combustion air distribution nozzle, which is provided with a fuel input channel, and the combustion air distribution nozzle is configured to control the fuel input channel to communicate with the first fuel hole or the fuel jet hole; An ignition device, which is arranged in the preheating and cooling chamber; The combustion air distribution nozzle includes a nozzle seat and a fuel input pipe. The nozzle seat is arranged on the furnace wall of the furnace body. The nozzle seat is provided with a rotating channel connected to the fuel nozzle. One end of the fuel input pipe is rotatably installed in the rotating channel. The fuel input channel is formed inside the fuel input pipe. One end of the fuel input pipe is provided with a fuel inlet, and the other end is eccentrically provided with at least one third fuel hole. One end of the fuel nozzle connected to the rotating channel is eccentrically provided with at least one fourth fuel hole. The fourth fuel hole communicates with the fuel jet hole. At least one of the first fuel holes is arranged on the outer peripheral wall of the rotating channel. The outer peripheral wall of the fuel input pipe is provided with at least one second fuel hole. The first fuel hole and the second fuel hole are located at the same axial position. The fuel input pipe is configured to control the on-off between the first fuel hole and the second fuel hole and the on-off between the third fuel hole and the fourth fuel hole by rotation.

2. The flameless combustion furnace according to claim 1, wherein: One end of the fuel nozzle connected to the rotating channel is provided with a first split baffle. The fourth fuel hole is arranged on the first split baffle. One end of the fuel input pipe close to the fuel nozzle is provided with a second split baffle. The third fuel hole is arranged on the second split baffle.

3. The flameless combustion furnace according to claim 2, wherein: A first rotation limiting portion is arranged at the central position of the first split baffle. A second rotation limiting portion is arranged at the central position of the second split baffle. The second rotation limiting portion is rotationally connected and matched with the first rotation limiting portion.

4. The flameless combustion furnace according to claim 2, wherein: The first fuel holes and the second fuel holes are respectively provided with a plurality of them. The plurality of first fuel holes are annularly spaced on the outer peripheral wall of the rotating channel. The plurality of second fuel holes are annularly spaced on the outer peripheral wall of the fuel input pipe.

5. The flameless combustion furnace according to claim 1, wherein: The nozzle seat is provided with an air pre-supply chamber which wraps around the center line and is located outside the fuel input pipe. The air injection holes are provided in plurality, and the plurality of air injection holes are annularly spaced on the outer peripheral wall of the nozzle seat and communicate with the air pre-supply chamber. The air pre-supply chamber is provided with an air inlet.

6. The flameless combustion furnace according to any one of claims 1 to 5, characterized in that: The preheating and cooling chamber includes a sequentially connected ignition chamber, a catalytic chamber and a confluence injection chamber. The ignition chamber and the confluence injection chamber are respectively located at two ends of the combustion chamber. The catalytic chamber is located on the outer peripheral side of the combustion chamber. The air injection holes and the first fuel injection holes respectively communicate with the ignition chamber. The air jet port communicates with the confluence injection chamber. The ignition device is arranged in the ignition chamber. The catalytic chamber is provided with a plurality of heat conducting fins extending from the ignition chamber to the confluence injection chamber. The plurality of heat conducting fins are annularly spaced. The heat conducting fins are connected to the outer peripheral wall of the combustion chamber and the inner peripheral wall of the catalytic chamber. The surface of the heat conducting fins is provided with a catalytic combustion catalyst.

7. The flameless combustion furnace according to claim 6, characterized in that: The fuel nozzle and the tail gas discharge port are located on the center line of the combustion chamber. The air jet ports are provided in plurality, and the plurality of air jet ports are annularly spaced on the side surface of the inner end of the tail gas discharge port. The jetting direction of the air jet ports is arranged along the inner wall of the combustion chamber. One end of the combustion chamber close to the tail gas discharge port is provided with a diversion inclined surface. The fuel jet holes are provided in plurality, and the plurality of fuel jet holes are distributed on the outer peripheral wall of the fuel nozzle.

8. The flameless combustion furnace according to claim 6, characterized in that: The ignition device is provided with a spark plug firing part and a spark plug terminal. The spark plug firing part is arranged outside the furnace body. The spark plug terminal is arranged in the ignition chamber. The distance between the spark plug terminal and the wall surface of the ignition chamber is between 3 mm and 10 mm.

9. A running method, characterized in that, It is applicable to the flameless combustion furnace according to any one of claims 1 to 8. The operation method includes: Controlling the fuel input channel to communicate with the first fuel injection hole; Feeding fuel into the preheating and cooling chamber, and injecting air into the preheating and cooling chamber through the air injection holes, so that the fuel and the air are mixed in the preheating and cooling chamber; Igniting and burning the fuel in the preheating and cooling chamber through the ignition device to heat the combustion chamber; When the chamber wall of the combustion chamber reaches a preset temperature, controlling the fuel input channel to communicate with the fuel jet holes; Injecting fuel into the combustion chamber through the fuel jet holes, and at the same time injecting air into the preheating and cooling chamber through the air injection holes and then entering the combustion chamber through the air jet ports, so that the fuel and the air are mixed and burned to start the flameless combustion furnace.

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