Flameless combustion system

Abstract

The utility model belongs to the technical field of combustion equipment, and discloses a flameless combustion system which comprises a combustion mechanism, a fuel conveying pipeline, a flue gas circulating pipeline and a combustion-supporting pipeline. The combustion mechanism comprises a combustor, a combustion chamber and a heat exchanger; the fuel conveying pipeline comprises a conveying branch and an ignition branch, the conveying branch communicates with the input end of the combustor, and the ignition branch communicates with the interior of the combustor; the flue gas circulation pipeline comprises a first circulation branch and a second circulation branch; and the combustion-supporting pipeline is communicated with the interior of the combustor. Thus, fuel gas enters the combustor in two paths, combustion-supporting air enters the combustor through the combustion-supporting pipeline, ignition and gas preliminary mixing can be achieved, the mixed gas continues to be combusted in the combustion chamber, and circulating flue gas carrying heat is circularly conveyed to the combustor and the combustion chamber in two paths. And sufficient combustion of gas can be promoted, and temperature and oxygen control can be carried out on the gas in the combustion chamber.

Description

Technical Field

[0001] The utility model relates to the technical field of combustion equipment, in particular to a flameless combustion system. Background Art

[0002] In the industrial production process, various process gases (such as nitrogen, oxygen, hydrogen, etc.) are often needed. The process gases need to pass through the heat exchanger to reach the preset temperature so that they can be better put into production, manufacturing, handling and processing. The heat transferred from the heat exchanger to the process gas is usually provided by the combustion equipment.

[0003] The combustion device is connected to two pipelines, one pipeline conveys fuel gas to the combustion device, and the other pipeline conveys combustion air to the combustion device, so that the fuel gas and the combustion air are burned in the combustion device, thereby transferring the generated heat to the heat exchanger.

[0004] However, when the fuel gas and combustion air are mixed in the combustion equipment, it is difficult to dynamically control the oxygen content concentration and the fuel gas concentration, which may result in incomplete combustion, making it difficult to control the heat output of the combustion equipment; the fuel gas may produce nitrogen oxides (i.e. NOx) during the combustion process, and excessive nitrogen oxides emitted to the outside will cause atmospheric pollution, and the flue gas emitted to the outside still carries heat, resulting in energy waste. Utility Model Content

[0005] The utility model aims to provide a flameless combustion system to solve the problems of low heat utilization rate and excessive nitrogen oxide emission of combustion equipment.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A flameless combustion system, comprising:

[0008] A combustion mechanism, the combustion mechanism comprising a burner, a combustion chamber and a heat exchanger, the output end of the burner is connected to the input end of the combustion chamber, and the output end of the combustion chamber is connected to the input end of the heat exchanger;

[0009] A fuel delivery pipeline, the fuel delivery pipeline comprising a delivery branch and an ignition branch, the delivery branch is communicated with the input end of the burner for delivering fuel gas to the inside of the burner, and the ignition branch is communicated with the inside of the burner for ignition;

[0010] A flue gas circulation pipeline, the flue gas circulation pipeline comprising a first circulation branch and a second circulation branch, the output end of the heat exchanger is respectively connected to the input end of the first circulation branch and the input end of the second circulation branch, the output end of the first circulation branch is connected to the inside of the burner, and the output end of the second circulation branch is connected to the inside of the combustion chamber;

[0011] A combustion-supporting pipeline is communicated with the interior of the burner and is used for conveying combustion-supporting air to the interior of the burner.

[0012] Preferably, the fuel delivery pipeline also includes a delivery main line, one end of which is connected to the delivery branch and the ignition branch; the flue gas circulation pipeline also includes a circulation main line, one end of which is connected to the inside of the output end of the heat exchanger, and the other end is connected to one end on the same side of the first circulation branch and the second circulation branch.

[0013] Preferably, the heat exchanger is connected to a smoke exhaust pipe, and the flow rate of the main circulation path is 1.5 times to 1.6 times that of the smoke exhaust pipe.

[0014] Preferably, the combustion-supporting pipeline comprises:

[0015] Helps to burn the main road;

[0016] A first combustion-supporting branch, one end of which is connected to the combustion-supporting main path, and the other end of which is connected to the input end of the burner, for mixing with the fuel gas for ignition;

[0017] A second combustion-supporting branch, one end of which is connected to the combustion-supporting main path, and the other end of which is connected to the interior of the burner.

[0018] Preferably, the delivery branch and the ignition branch are both provided with flow regulating components; and / or, the combustion-supporting main circuit is provided with a flow regulating component; and / or, the circulation main circuit is provided with a flow regulating component.

[0019] Preferably, the flow regulating member is a flow regulating valve.

[0020] Preferably, the burner is provided with a delivery pipeline, an ignition pipeline, a combustion-supporting pipeline and a circulation pipeline. The delivery pipeline and the ignition pipeline are arranged at the input end of the burner, the delivery branch is connected to the delivery pipeline, the ignition branch and the first combustion-supporting branch are respectively connected to the ignition pipeline, the second combustion-supporting branch is connected to the combustion-supporting pipeline, and the first circulation branch is connected to the circulation pipeline.

[0021] Preferably, the combustion-supporting main circuit is provided with a combustion-supporting gas driving component; and / or the circulation main circuit is provided with a circulation gas driving component.

[0022] Preferably, the ignition branch is provided with a permanent lamp.

[0023] Preferably, the combustion chamber is a horizontal furnace; and / or the heat exchanger is a vertical shell and tube air preheater.

[0024] Beneficial effects of the utility model:

[0025] A flameless combustion system comprises: a combustion mechanism, wherein the combustion mechanism comprises a burner, a combustion chamber and a heat exchanger, the output end of the burner is connected to the input end of the combustion chamber, and the output end of the combustion chamber is connected to the input end of the heat exchanger; a fuel delivery pipeline, wherein the fuel delivery pipeline comprises a delivery branch and an ignition branch, the delivery branch is connected to the input end of the burner and is used to deliver fuel gas to the inside of the burner, and the ignition branch is connected to the inside of the burner for ignition; a flue gas circulation pipeline, wherein the flue gas circulation pipeline comprises a first circulation branch and a second circulation branch, the output end of the heat exchanger is respectively connected to the input end of the first circulation branch and the input end of the second circulation branch, the output end of the first circulation branch is connected to the inside of the burner, and the output end of the second circulation branch is connected to the inside of the combustion chamber; a combustion-supporting pipeline, wherein the combustion-supporting pipeline is connected to the inside of the burner and is used to deliver combustion-supporting air to the inside of the burner.

[0026] In this way, the fuel gas is transported to the inside of the burner through the delivery branch and the ignition branch, mixed with the combustion-supporting air and ignited, so that the ignited mixed gas enters the combustion chamber to continue burning. The heat-carrying gas transported through the combustion chamber enters the heat exchanger to heat the process gas in the heat exchanger to reach a predetermined temperature. Part of the mixed flue gas output from the output end of the heat exchanger is circulated and transported to the burner and the combustion chamber in two ways, which can dynamically adjust the oxygen content in the burner and the combustion chamber, so that the fuel gas can be fully burned in a high-temperature and low-oxygen environment, reducing the generation of nitrogen oxides and improving combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a flameless combustion system in one embodiment of the utility model;

[0028] Figure 2 It is a partial enlarged view of point A in one embodiment of the utility model.

[0029] In the figure:

[0030] 1. Combustion mechanism; 11. Burner; 111. Delivery pipeline; 112. Ignition pipeline; 113. Combustion-supporting pipeline; 114. Circulation pipeline; 12. Combustion chamber; 13. Heat exchanger; 2. Fuel delivery pipeline; 21. Delivery branch; 22. Ignition branch; 221. Ever-burning lamp; 23. Delivery main pipeline; 3. Flue gas circulation pipeline; 31. Circulation main pipeline; 311. Circulation gas driving element; 32. First circulation branch; 33. Second circulation branch; 4. Combustion-supporting pipeline; 41. Combustion-supporting main pipeline; 411. Combustion-supporting gas driving element; 42. First combustion-supporting branch; 43. Second combustion-supporting branch. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0032] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0035] See also Figure 1The utility model provides a flameless combustion system, including a combustion mechanism 1, a fuel delivery pipeline 2, a flue gas circulation pipeline 3 and a combustion-supporting pipeline 4. The combustion mechanism 1 includes a burner 11, a combustion chamber 12 and a heat exchanger 13. The output end of the burner 11 is connected to the input end of the combustion chamber 12, and the output end of the combustion chamber 12 is connected to the input end of the heat exchanger 13. The fuel delivery pipeline 2 includes a delivery branch 21 and an ignition branch 22. The delivery branch 21 is connected to the input end of the burner 11 and is used to deliver fuel gas to the inside of the burner 11. The ignition branch 22 is connected to the inside of the burner 11 for ignition. The flue gas circulation pipeline 3 includes a first circulation branch 32 and a second circulation branch 33. The output end of the heat exchanger 13 is respectively connected to the input end of the first circulation branch 32 and the input end of the second circulation branch 33. The output end of the first circulation branch 32 is connected to the inside of the burner 11, and the output end of the second circulation branch 33 is connected to the inside of the combustion chamber 12. The combustion-supporting pipeline 4 is in communication with the interior of the burner 11 and is used for conveying combustion-supporting air to the interior of the burner 11 .

[0036] In this embodiment, the combustion chamber 12 is a horizontal furnace, the heat exchanger 13 is a vertical shell and tube air preheater, the high-temperature flue gas generated by the combustion chamber 12 goes through the shell side, and the process gas to be preheated goes through the tube side. The burner 11 and the heat exchanger 13 are respectively arranged at both ends of the combustion chamber 12, and the fuel delivery pipeline 2 is arranged at the end of the burner 11 away from the combustion chamber 12; an integrated igniter is arranged inside the burner 11.

[0037] In this way, the fuel gas enters the burner 11 in two ways through the delivery branch 21 and the ignition branch 22, and the combustion air enters the burner 11 through the combustion pipeline 4, so that the fuel gas and the combustion air are mixed in the burner 11. Under the action of the igniter, the burning fuel gas enters the combustion chamber 12 and continues to burn, so that the airflow carrying heat enters the heat exchanger 13 and heats the process gas in the heat exchanger 13. Part of the flue gas output from the output end of the heat exchanger 13 is transported to the burner 11 through the first circulation branch 32 and to the combustion chamber 12 through the second circulation branch 33, so that the flue gas and the fuel gas are further promoted to burn. At the same time, the heat carried by the flue gas can heat the gas in the burner 11 and the combustion chamber 12, so that the fuel gas is fully burned, reducing the emission of nitrogen oxides, facilitating the control of the heat and temperature generated during the combustion process, and reducing energy waste and environmental pollution.

[0038] See also Figure 1In some embodiments, the fuel delivery pipeline 2 further includes a delivery main path 23, one end of which is connected to the delivery branch 21 and the ignition branch 22. The flue gas circulation pipeline 3 further includes a circulation main path 31, one end of which is connected to the output end of the heat exchanger 13, and the other end is connected to the first circulation branch 32 and the second circulation branch 33 on the same side. Furthermore, the heat exchanger 13 is connected to a smoke exhaust pipe, and the flow rate of the circulation main path 31 is 1.5-1.6 times that of the smoke exhaust pipe.

[0039] In this embodiment, one end of the main transport path 23 is connected to a transport gas driving member (not shown in the figure) for transporting fuel gas into the main transport path 23; one end of the circulation main path 31 is connected to the outlet flue of the heat exchanger 13.

[0040] In this way, the fuel gas enters the delivery branch 21 and the ignition branch 22 respectively through the delivery main path 23, thereby realizing the diversion of the fuel gas, so that one part of the fuel gas is used for ignition and the other part is used for combustion; the flue gas carrying heat in the heat exchanger 13 enters the first circulation branch 32 and the second circulation branch 33 respectively through the circulation main path 31, thereby realizing the diversion of the circulating flue gas, so that one part of the circulating flue gas is used to mix with the gas in the burner 11, and the other part is mixed with the gas in the combustion chamber 12. The mixing of the circulating flue gas and the gas can not only make the fuel gas burn fully, but the heat it carries can also preheat the gas, thereby improving energy utilization and combustion efficiency, and reducing the nitrogen oxide content of the gas discharged to the outside through the heat exchanger 13 after the circulation combustion.

[0041] It can be understood that the specific materials of the fuel delivery pipeline 2 and the flue gas circulation pipeline 3, and the specific structure of the gas delivery driving component can be adjusted according to actual needs. In this embodiment, the main delivery line 23, the delivery branch line 21, and the ignition branch line 22 are all carbon steel seamless steel pipes, and the gas delivery driving component is a fan. The fuel delivery pipeline 2 is also provided with a quick shut-off valve, a flame arrester, a flow meter, and a pressure gauge to measure the gas flow rate inside the pipeline and control the gas flow. The flue gas circulation pipeline 3 is also provided with an electric damper, a flow meter, a thermometer, and a differential pressure transmitter to measure and control the gas in the flue gas circulation pipeline 3.

[0042] See also Figure 1 and Figure 2 In some embodiments, the combustion-supporting pipeline 4 includes a combustion-supporting main pipeline 41, a first combustion-supporting branch pipeline 42, and a second combustion-supporting branch pipeline 43. One end of the first combustion-supporting branch pipeline 42 is connected to the combustion-supporting main pipeline 41, and the other end is connected to the input end of the burner 11, and is used for mixing with the fuel gas for ignition. One end of the second combustion-supporting branch pipeline 43 is connected to the combustion-supporting main pipeline 41, and the other end is connected to the inside of the burner 11.

[0043] In this way, the combustion-supporting air is delivered to the interior of the burner 11 through the first combustion-supporting branch 42, and the combustion-supporting air inside the burner 11 is mixed with the fuel gas delivered to the interior of the burner 11 through the ignition branch 22, and can burn under the action of the igniter, and promote the overall mixed gas to burn fully, thereby improving the combustion efficiency; the combustion-supporting air is delivered to the interior of the burner 11 through the second combustion-supporting branch 43, and can mix with the gas inside the burner 11, so that the mixed gas burns more fully, reduces the combustion of nitrogen oxides, and improves the combustion efficiency.

[0044] See also Figure 1 In some embodiments, flow regulating components are provided on the delivery branch 21, the ignition branch 22, the combustion-supporting main path 41 and the circulation main path 31. The flow regulating components are flow regulating valves.

[0045] In this way, by setting up flow regulating components, the flow rates on the delivery branch 21, the ignition branch 22, the combustion-supporting main path 41 and the circulation main path 31 can be dynamically adjusted, thereby respectively adjusting the flow rates of the fuel gas used for combustion, the fuel gas used for ignition, the combustion-supporting air used for preliminary combustion, and the mixed flue gas used for further mixing with the gas to promote combustion, so as to achieve the effect of flameless combustion, reduce nitrogen oxides, improve combustion efficiency, and reduce environmental pollution.

[0046] It is understandable that the specific structure and type of the flow regulating component can be adjusted according to actual needs, as long as it can adjust the flow of the pipeline connected to it, and no further examples are given here.

[0047] See also Figure 2 In some embodiments, the burner 11 is provided with a delivery pipeline 111, an ignition pipeline 112, a combustion-supporting pipeline 113 and a circulation pipeline 114. The delivery pipeline 111 and the ignition pipeline 112 are arranged at the input end of the burner 11, the delivery branch 21 is connected to the delivery pipeline 111, the ignition branch 22 and the first combustion-supporting branch 42 are respectively connected to the ignition pipeline 112, the second combustion-supporting branch 43 is connected to the combustion-supporting pipeline 113, and the first circulation branch 32 is connected to the circulation pipeline 114. Among them, the igniter is connected to the ignition pipeline 112.

[0048] In this way, the fuel gas delivered through the ignition branch 22 and the combustion air delivered through the first combustion branch 42 are mixed through the ignition pipe 112 and delivered to the igniter, thereby improving the ignition efficiency, allowing the mixed gas in the burner 11 and the combustion chamber 12 to be fully burned, and reducing the generation of nitrogen oxides.

[0049] See also Figure 1 In some embodiments, the combustion-supporting main path 41 is provided with a combustion-supporting gas driving component 411 , and the circulation main path 31 is provided with a circulation gas driving component 311 .

[0050] In this way, the combustion-supporting air and the circulating flue gas can be transported to the combustion-supporting main path 41 and the circulating main path 31 respectively under the action of the combustion-supporting gas driving component 411 and the circulating gas driving component 311. The combustion-supporting gas driving component 411 can ensure the supply of the air volume required for combustion, and the circulating gas driving component 311 can improve the heat utilization rate, reduce the content of nitrogen oxides in the flue gas, and control the combustion temperature. By further controlling the gas flow rate, the combustion efficiency can be dynamically adjusted to improve the energy utilization rate.

[0051] It is understandable that the specific structures of the combustion-supporting gas driving component 411 and the circulating gas driving component 311 can be adjusted according to actual needs, and no further examples are given here. In this embodiment, the combustion-supporting gas driving component 411 and the circulating gas driving component 311 are both fans.

[0052] See also Figure 1 In some embodiments, the ignition branch 22 is provided with a permanent lamp 221 .

[0053] In this way, the ever-burning lamp 221 can not only show whether there is sufficient fuel gas in the ignition branch 22 for ignition, but also serve as an indication during ignition, so as to facilitate the staff to carry out ignition work and avoid the situation where normal ignition is affected by insufficient fuel gas.

[0054] It is understandable that the location and number of the ever-burning lamps 221 can be adjusted according to actual needs, and no further details are given here.

[0055] The use process of the flameless combustion system is as follows:

[0056] When in use, nitrogen is introduced into the fuel delivery pipeline 2 to replace the gas in the pipeline, and then the fuel gas is delivered to the burner 11 through the fuel delivery pipeline 2, and the combustion-supporting air is delivered to the burner 11 through the combustion-supporting pipeline 4. The long-lasting lamp 221 lights up after detecting the gas in the ignition branch 22, and the ignition program is started to burn the mixed fuel gas in the ignition pipe 112, and the mixed gas in the burner 11 is delivered to the combustion chamber 12 for further combustion, and carries heat into the heat exchanger 13, and the circulating gas drive 311 is started, so that the flue gas at the flue outlet of the heat exchanger 13 circulates through the flue gas circulation pipeline 3 into the burner 11 and the combustion chamber 12.

[0057] The inlet flue gas temperature of the heat exchanger 13 is controlled at 800°C-930°C, the furnace pressure is 5kpa, and the temperature of the heated process gas after passing through the heat exchanger 13 is 550°C-650°C. By dynamically adjusting the fuel gas, combustion air, and circulating flue gas content delivered to the burner 11, flameless combustion can be achieved, and the combustion efficiency and energy utilization rate can be improved.

[0058] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A flameless combustion system, characterized in that: include: A combustion mechanism (1), the combustion mechanism (1) comprising a burner (11), a combustion chamber (12) and a heat exchanger (13), the output end of the burner (11) being in communication with the input end of the combustion chamber (12), and the output end of the combustion chamber (12) being in communication with the input end of the heat exchanger (13); A fuel delivery pipeline (2), the fuel delivery pipeline (2) comprising a delivery branch (21) and an ignition branch (22), the delivery branch (21) being in communication with an input end of the burner (11) and being used for delivering fuel gas to the interior of the burner (11), and the ignition branch (22) being in communication with the interior of the burner (11) and being used for ignition; A flue gas circulation pipeline (3), the flue gas circulation pipeline (3) comprising a first circulation branch (32) and a second circulation branch (33), the output end of the heat exchanger (13) being respectively connected to the input end of the first circulation branch (32) and the input end of the second circulation branch (33), the output end of the first circulation branch (32) being connected to the interior of the burner (11), and the output end of the second circulation branch (33) being connected to the interior of the combustion chamber (12); A combustion-supporting pipeline (4), the combustion-supporting pipeline (4) being in communication with the interior of the burner (11) and being used for conveying combustion-supporting air to the interior of the burner (11).

2. The flameless combustion system according to claim 1, characterized in that: The fuel delivery pipeline (2) further comprises a delivery main path (23), one end of which is connected to both the delivery branch path (21) and the ignition branch path (22); the flue gas circulation pipeline (3) further comprises a circulation main path (31), one end of which is connected to the inside of the output end of the heat exchanger (13), and the other end of which is connected to both ends of the first circulation branch path (32) and the second circulation branch path (33) on the same side.

3. The flameless combustion system according to claim 2, characterized in that: The heat exchanger (13) is connected to a smoke exhaust pipe, and the flow rate of the main circulation path (31) is 1.5 to 1.6 times that of the smoke exhaust pipe.

4. The flameless combustion system according to claim 2, characterized in that: The combustion-supporting pipeline (4) comprises: combustion main road (41); A first combustion-supporting branch (42), one end of which is connected to the combustion-supporting main path (41), and the other end of which is connected to the input end of the burner (11), and is used for mixing with the fuel gas for ignition; A second combustion-supporting branch (43), one end of which is in communication with the combustion-supporting main path (41), and the other end of which is in communication with the interior of the burner (11).

5. The flameless combustion system according to claim 4, characterized in that: The delivery branch (21) and the ignition branch (22) are both provided with flow regulating components; and / or the combustion-supporting main path (41) is provided with a flow regulating component; and / or the circulation main path (31) is provided with a flow regulating component.

6. The flameless combustion system according to claim 5, characterized in that: The flow regulating component is a flow regulating valve.

7. The flameless combustion system according to claim 4, characterized in that: The burner (11) is provided with a delivery pipeline (111), an ignition pipeline (112), a combustion-supporting pipeline (113) and a circulation pipeline (114); the delivery pipeline (111) and the ignition pipeline (112) are arranged at the input end of the burner (11); the delivery branch (21) is connected to the delivery pipeline (111); the ignition branch (22) and the first combustion-supporting branch (42) are respectively connected to the ignition pipeline (112); the second combustion-supporting branch (43) is connected to the combustion-supporting pipeline (113); and the first circulation branch (32) is connected to the circulation pipeline (114).

8. The flameless combustion system according to claim 4, characterized in that: The combustion-supporting main path (41) is provided with a combustion-supporting gas driving component (411); and / or the circulation main path (31) is provided with a circulation gas driving component (311).

9. The flameless combustion system according to any one of claims 1 to 8, characterized in that: The ignition branch circuit (22) is provided with a permanent lamp (221).

10. The flameless combustion system according to any one of claims 1 to 8, characterized in that: The combustion chamber (12) is a horizontal furnace; and / or the heat exchanger (13) is a vertical shell and tube air preheater.

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