CO2-rich flue gas injection heat insulation combustion furnace for oxygen-rich combustion carbon capture

Abstract

The invention provides a CO2-rich flue gas injection heat-insulation combustion furnace for oxygen-rich combustion carbon capture, which is characterized in that a furnace wall outer shell and a furnace wall inner shell are arranged, and holes are formed in the furnace wall inner shell, so that a combustion furnace inner cavity and a combustion furnace interlayer which are communicated with each other through the holes formed in the furnace wall inner shell are formed; part of combustion tail gas is extracted to serve as backflow gas to enter the interlayer of the combustion furnace and is sprayed into the inner cavity of the combustion furnace through holes formed in the inner shell of the furnace wall, a gas film heat insulation layer is formed in the inner shell of the furnace wall of the inner cavity of the combustion furnace, and the heating effect of oxygen-enriched combustion reaction in the inner cavity of the combustion furnace on the furnace wall is reduced; after combustion tail gas is repeatedly refluxed, the concentration of carbon dioxide in the combustion tail gas is continuously increased, and enrichment of carbon dioxide in the flue gas is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of carbon dioxide tail gas recovery and oxygen-enriched combustion, and in particular to a CO2-rich flue gas injection insulated combustion furnace for carbon capture by oxygen-enriched combustion. Background Art

[0002] At present, the demand for energy conservation and emission reduction in the glass industry, metallurgical industry, thermal energy engineering and other fields has increased. Oxygen-enriched combustion technology uses high-purity oxygen instead of combustion air to significantly reduce the amount of combustion air and flue gas generated, which has a significant energy-saving effect. Among them, the purification, separation and recovery of carbon dioxide tail gas has important social benefits. The development and application of carbon dioxide tail gas recovery technology can not only effectively reduce greenhouse gas emissions, but also facilitate the capture and compression of CO2.

[0003] At present, oxygen-enriched combustion furnaces use pure oxygen or high-concentration oxygen as oxidants, which significantly improves combustion efficiency and thermal efficiency and reduces pollutant emissions, but also brings higher initial investment and operating costs. Most oxygen-enriched combustion furnaces have higher requirements on high temperature resistance and safety of equipment due to the high temperature and high concentration of oxygen environment, and the maintenance cost is high.

[0004] In summary, it is necessary to develop a CO2-rich flue gas injection insulated combustion furnace for oxy-combustion carbon capture. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-enriched combustion and carbon capture, by arranging a furnace wall outer shell and a furnace wall inner shell, and opening holes in the furnace wall inner shell, to form a combustion furnace inner cavity and a combustion furnace interlayer connected by the holes opened in the furnace wall inner shell; a part of the combustion exhaust gas is extracted as reflux gas to enter the combustion furnace interlayer and is injected into the combustion furnace inner cavity through the holes opened in the furnace wall inner shell, to form an air film insulation layer at the furnace wall inner shell of the combustion furnace inner cavity, to reduce the temperature increase effect of the oxygen-rich combustion reaction in the combustion furnace inner cavity on the furnace wall, and at the same time, after the combustion exhaust gas is repeatedly refluxed, the carbon dioxide concentration in the combustion exhaust gas is continuously increased, thereby achieving the enrichment of carbon dioxide in the flue gas.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The object of the present invention is to provide a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, comprising a furnace wall outer shell, a furnace wall inner shell is arranged inside the furnace wall outer shell, a combustion furnace inner cavity is formed inside the furnace wall inner shell, and a combustion furnace interlayer is formed between the furnace wall inner shell and the furnace wall outer shell; holes are provided on the sides of the furnace wall inner shell, and the combustion furnace inner cavity and the combustion furnace interlayer are connected through the holes provided in the furnace wall inner shell;

[0008] A mixing feed port is provided at the bottom of the furnace wall shell for passing a mixture of fuel and oxygen-rich gas into the inner cavity of the combustion furnace; a combustion exhaust gas discharge port is provided at the top of the furnace wall shell, and the combustion exhaust gas discharge port is connected to the inlet of the waste heat recovery device, and is used to discharge the combustion exhaust gas in the inner cavity of the combustion furnace and introduce it into the waste heat recovery device;

[0009] A reflux gas inlet is also provided at the bottom of the furnace wall shell; the outlet of the waste heat recovery device is connected to the diversion controller, and the combustion exhaust gas after waste heat recovery is divided into two parts, the first part is used as product gas for oxygen-enriched combustion carbon capture, and the second part is returned to the reflux gas inlet as reflux gas, enters the combustion furnace interlayer, and is injected into the combustion furnace cavity through the holes provided in the furnace wall inner shell.

[0010] It should be noted that the pipeline corresponding to the mixed feed port goes deep into the inner cavity of the combustion furnace, and is respectively welded and connected to the outer shell of the furnace wall and the inner shell of the furnace wall to ensure air tightness; similarly, the pipeline corresponding to the combustion exhaust gas discharge port goes deep into the inner cavity of the combustion furnace, and is respectively welded and connected to the outer shell of the furnace wall and the inner shell of the furnace wall to ensure air tightness. The waste heat recovery device can make full use of the heat of the combustion exhaust gas, and the obtained cooled exhaust gas is then divided into two parts through the diversion controller. The first part is used as product gas for oxygen-enriched combustion carbon capture, and the second part is returned to the reflux gas inlet as reflux gas, enters the interlayer of the combustion furnace, and is sprayed into the inner cavity of the combustion furnace through the holes opened in the inner shell of the furnace wall.

[0011] The present invention provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, wherein a portion of the combustion exhaust gas is extracted as reflux gas and enters the combustion furnace interlayer and is injected into the combustion furnace inner cavity through holes opened in the furnace wall inner shell, and the reflux gas flows along the furnace wall in the combustion furnace inner cavity to form a vortex, which serves as an air film insulation layer to reduce the temperature increase effect of the oxygen-rich combustion reaction in the combustion furnace inner cavity on the furnace wall, and at the same time, after the combustion exhaust gas is repeatedly refluxed, the carbon dioxide concentration in the combustion exhaust gas is continuously increased, thereby achieving the enrichment of carbon dioxide in the product gas.

[0012] The present invention provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, which reduces the operating temperature of the combustion furnace equipment, reduces the high-temperature resistance requirements of the equipment materials, improves the durability of the equipment, and can also increase the CO2 content in the combustion exhaust gas; the equipment has low maintenance costs and high CO2 recovery concentration.

[0013] The present invention provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, which can establish an injection insulation layer inside the combustion furnace, thereby reducing the contact temperature of the furnace body material, and the combustion tail gas produced is rich in carbon dioxide gas, the product carbon dioxide has a higher purity and is easier to recover; the equipment production is highly economical, the maintenance cost is low, the CO2 recovery concentration is high, and the investment and operating costs of the production enterprise are effectively reduced.

[0014] As a preferred technical solution of the present invention, the holes are inclined upward from outside to inside, so that the reflux gas entering the combustion furnace interlayer is sprayed into the combustion furnace cavity along an oblique upward direction.

[0015] As a preferred technical solution of the present invention, relative to the horizontal plane, the central axis of the hole is inclined upward at an angle of 30-60 degrees, such as 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees or 60 degrees.

[0016] As a preferred technical solution of the present invention, along the radial direction, the radial deviation angle of the central axis of the hole is 60-85 degrees, for example, 60 degrees, 63 degrees, 65 degrees, 68 degrees, 70 degrees, 72 degrees, 75 degrees, 77 degrees, 80 degrees, 83 degrees or 85 degrees, so that the reflux gas entering the combustion furnace interlayer forms a swirl.

[0017] As a preferred technical solution of the present invention, the hole shape of the hole is a conical hole, and the aperture of the conical hole decreases from the outside to the inside. The diameter of the large end of the conical hole is 3-20mm, for example, 3mm, 5mm, 7mm, 10mm, 13mm, 15mm, 18mm or 20mm, etc., and the diameter of the small end of the conical hole is 2-15mm, for example, 2mm, 5mm, 7mm, 10mm, 13mm or 15mm, etc.

[0018] As a preferred technical solution of the present invention, the arrangement of the holes is in the form of an equilateral triangle or a square, and the center distance between two adjacent holes is 1.5-10 times the diameter of the hole, such as 1.5 times, 3 times, 4.5 times, 6 times, 7.5 times, 9 times or 10 times. It should be noted that when the hole shape of the hole is a tapered hole, the center distance between two adjacent holes is 1.5-10 times the diameter of the large end of the tapered hole.

[0019] As a preferred technical solution of the present invention, on the outside of the furnace wall shell, the mixed feed port is formed by the fuel feed port and the oxygen-enriched gas inlet port, the fuel feed port is used to introduce fuel, and the oxygen-enriched gas inlet port is used to introduce oxygen-enriched gas. For example, the fuel feed port is used to fill solid combustion materials, and the oxygen-enriched gas inlet port is used to connect the oxygen-enriched gas provided upstream.

[0020] As a preferred technical solution of the present invention, a heat exchanger is arranged at the top of the inner cavity of the combustion furnace to achieve heat exchange between the combustion exhaust gas and the fluid flowing inside the heat exchanger, so as to recover part of the heat of the combustion exhaust gas.

[0021] It should be noted that there is fluid flowing inside the heat exchanger, and the flowing fluid can achieve heat exchange with the combustion exhaust gas, thereby recovering the combustion heat. After the combustion exhaust gas flows through the heat exchanger, the temperature of the combustion exhaust gas will decrease with the heat exchange.

[0022] As a preferred technical solution of the present invention, the diversion controller includes a diversion control valve.

[0023] As a preferred technical solution of the present invention, a blower is arranged on the pipeline for the reflux gas to return to the interlayer of the combustion furnace.

[0024] As a preferred technical solution of the present invention, a buffer tank is provided at the outlet of the blower.

[0025] It should be noted that the blower can pressurize the reflux gas, and the buffer tank stabilizes the pressure of the pressurized reflux gas.

[0026] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0027] The present invention provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, wherein a portion of the combustion exhaust gas is extracted as reflux gas and enters the combustion furnace interlayer and is injected into the combustion furnace inner cavity through holes opened in the furnace wall inner shell, and the reflux gas flows along the furnace wall in the combustion furnace inner cavity to form a vortex, which serves as an air film insulation layer to reduce the temperature increase effect of the oxygen-rich combustion reaction in the combustion furnace inner cavity on the furnace wall, and at the same time, after the combustion exhaust gas is repeatedly refluxed, the carbon dioxide concentration in the combustion exhaust gas is continuously increased, thereby achieving the enrichment of carbon dioxide in the product gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of a CO2-rich flue gas injection insulated combustion furnace for carbon capture by oxygen-rich combustion according to Example 1 of the present invention;

[0029] Figure 2 is a schematic diagram of the radial deviation angle of the hole in Example 1 of the present invention;

[0030] In the figure: 1-furnace wall outer shell; 2-furnace wall inner shell; 3-combustion furnace cavity; 4-combustion furnace interlayer; 5-hole; 6-heat exchanger; 7-combustion tail gas discharge port; 8-waste heat recovery device; 9-diversion controller; 10-blower; 11-buffer tank; 12-reflux gas inlet; 13-mixing feed port; 14-fuel feed port; 15-oxygen-enriched gas inlet. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0032] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0033] Example 1

[0034] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, such as Figure 1 As shown, it comprises a furnace wall outer shell 1, a furnace wall inner shell 2 is arranged inside the furnace wall outer shell 1, a combustion furnace cavity 3 is formed inside the furnace wall inner shell 2, and a combustion furnace interlayer 4 is formed between the furnace wall inner shell 2 and the furnace wall outer shell 1; holes 5 are provided on the sides of the furnace wall inner shell 2, and the combustion furnace cavity 3 is connected to the combustion furnace interlayer 4 through the holes 5 provided on the furnace wall inner shell 2;

[0035] The bottom of the furnace wall shell 1 is provided with a mixing feed port 13 for introducing a mixture of fuel and oxygen-rich gas into the combustion furnace cavity 3; the top of the furnace wall shell 1 is provided with a combustion exhaust gas discharge port 7, and the combustion exhaust gas discharge port 7 is connected to the inlet of the waste heat recovery device 8, and is used to discharge the combustion exhaust gas in the combustion furnace cavity and introduce it into the waste heat recovery device 8;

[0036] A reflux gas inlet 12 is also provided at the bottom of the furnace wall shell 1; the outlet of the waste heat recovery device 8 is connected to the diversion controller 9, and the combustion tail gas after waste heat recovery is divided into two parts, the first part is used as product gas for oxygen-enriched combustion carbon capture, and the second part is returned to the reflux gas inlet 12 as reflux gas, enters the combustion furnace interlayer 4, and is injected into the combustion furnace cavity 3 through the hole 5 provided in the furnace wall inner shell 2;

[0037] The hole 5 is inclined upward from the outside to the inside, so that the reflux gas entering the combustion furnace interlayer 4 is ejected into the combustion furnace cavity 3 in an oblique upward direction; the central axis of the hole 5 is inclined upward at an angle of 45 degrees relative to the horizontal plane; Figure 2 The radial deflection angle of the hole is schematically shown. In the radial direction, the radial deflection angle of the central axis of the hole 5 (i.e. Figure 2 The angle θ) is 70 degrees, so that the reflux gas entering the combustion furnace interlayer 4 forms a swirl; the hole shape of the hole is a conical hole, and the aperture of the conical hole decreases from the outside to the inside. The diameter of the large end of the conical hole is 15mm, and the diameter of the small end of the conical hole is 8mm; the arrangement of the holes is an equilateral triangle, and the center distance between two adjacent holes is 3 times the diameter of the large end of the conical hole;

[0038] On the outside of the furnace wall shell 1, the mixed feed port 13 is formed by the fuel feed port 14 and the oxygen-rich gas inlet 15. The fuel feed port 14 is used to introduce fuel, and the oxygen-rich gas inlet 15 is used to introduce oxygen-rich gas.

[0039] A heat exchanger 6 is provided at the top of the combustion furnace inner cavity 3, for achieving heat exchange between the combustion exhaust gas and the fluid flowing inside the heat exchanger 6, so as to recover part of the heat of the combustion exhaust gas;

[0040] The diversion controller 9 includes a diversion control valve; a blower 10 is arranged on the pipeline for the reflux gas to return to the combustion furnace interlayer 4, and a buffer tank 11 is arranged at the outlet of the blower 10.

[0041] Example 2

[0042] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture. Compared with Embodiment 1, the only difference is that the hole 5 is arranged horizontally relative to the horizontal plane.

[0043] Example 3

[0044] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture. Compared with Embodiment 1, the only difference is that the central axis of the hole 5 is inclined upward at an angle of 20 degrees relative to the horizontal plane.

[0045] Example 4

[0046] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture. Compared with Embodiment 1, the only difference is that the central axis of the hole 5 is inclined upward at an angle of 70 degrees relative to the horizontal plane.

[0047] Example 5

[0048] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture. Compared with Embodiment 1, the only difference is that along the radial direction, the radial deviation angle of the central axis of the hole 5 is 55 degrees.

[0049] Example 6

[0050] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture. Compared with Example 1, the only difference is that the hole shape is a single-diameter circular hole, and the hole diameter is 15 mm.

[0051] Example 7

[0052] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, which has a structure basically the same as that of Embodiment 1, and comprises a furnace wall outer shell 1, a furnace wall inner shell 2 is arranged inside the furnace wall outer shell 1, a combustion furnace inner cavity 3 is formed inside the furnace wall inner shell 2, and a combustion furnace interlayer 4 is formed between the furnace wall inner shell 2 and the furnace wall outer shell 1; holes 5 are provided on the sides of the furnace wall inner shell 2, and the combustion furnace inner cavity 3 is connected to the combustion furnace interlayer 4 through the holes 5 provided on the furnace wall inner shell 2;

[0053] The bottom of the furnace wall shell 1 is provided with a mixing feed port 13 for introducing a mixture of fuel and oxygen-rich gas into the combustion furnace cavity 3; the top of the furnace wall shell 1 is provided with a combustion exhaust gas discharge port 7, and the combustion exhaust gas discharge port 7 is connected to the inlet of the waste heat recovery device 8, and is used to discharge the combustion exhaust gas in the combustion furnace cavity and introduce it into the waste heat recovery device 8;

[0054] A reflux gas inlet 12 is also provided at the bottom of the furnace wall shell 1; the outlet of the waste heat recovery device 8 is connected to the diversion controller 9, and the combustion tail gas after waste heat recovery is divided into two parts, the first part is used as product gas for oxygen-enriched combustion carbon capture, and the second part is returned to the reflux gas inlet 12 as reflux gas, enters the combustion furnace interlayer 4, and is injected into the combustion furnace cavity 3 through the hole 5 provided in the furnace wall inner shell 2;

[0055] Among them, along the direction from outside to inside, the hole 5 is inclined upward, so that the reflux gas entering the combustion furnace interlayer 4 is sprayed into the combustion furnace cavity 3 along the oblique upward direction; relative to the horizontal plane, the central axis of the hole 5 is inclined upward at an angle of 30 degrees; along the radial direction, the radial deflection angle of the central axis of the hole 5 is 85 degrees, so that the reflux gas entering the combustion furnace interlayer 4 forms a swirl; the hole shape of the hole is a conical hole, and along the direction from outside to inside, the aperture of the conical hole decreases, the large end diameter of the conical hole is 10mm, and the small end diameter of the conical hole is 5mm; the arrangement of the holes is an equilateral triangle, and the center distance between two adjacent holes is 1.5 times the large end diameter of the conical hole;

[0056] On the outside of the furnace wall shell 1, the mixed feed port 13 is formed by the fuel feed port 14 and the oxygen-rich gas inlet 15. The fuel feed port 14 is used to introduce fuel, and the oxygen-rich gas inlet 15 is used to introduce oxygen-rich gas.

[0057] A heat exchanger 6 is provided at the top of the combustion furnace inner cavity 3, for achieving heat exchange between the combustion exhaust gas and the fluid flowing inside the heat exchanger 6, so as to recover part of the heat of the combustion exhaust gas;

[0058] The diversion controller 9 includes a diversion control valve; a blower 10 is arranged on the pipeline for the reflux gas to return to the combustion furnace interlayer 4, and a buffer tank 11 is arranged at the outlet of the blower 10.

[0059] Example 8

[0060] This embodiment provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, which has a structure basically the same as that of Embodiment 1, and comprises a furnace wall outer shell 1, a furnace wall inner shell 2 is arranged inside the furnace wall outer shell 1, a combustion furnace inner cavity 3 is formed inside the furnace wall inner shell 2, and a combustion furnace interlayer 4 is formed between the furnace wall inner shell 2 and the furnace wall outer shell 1; holes 5 are provided on the sides of the furnace wall inner shell 2, and the combustion furnace inner cavity 3 is connected to the combustion furnace interlayer 4 through the holes 5 provided on the furnace wall inner shell 2;

[0061] The bottom of the furnace wall shell 1 is provided with a mixing feed port 13 for introducing a mixture of fuel and oxygen-rich gas into the combustion furnace cavity 3; the top of the furnace wall shell 1 is provided with a combustion exhaust gas discharge port 7, and the combustion exhaust gas discharge port 7 is connected to the inlet of the waste heat recovery device 8, and is used to discharge the combustion exhaust gas in the combustion furnace cavity and introduce it into the waste heat recovery device 8;

[0062] A reflux gas inlet 12 is also provided at the bottom of the furnace wall shell 1; the outlet of the waste heat recovery device 8 is connected to the diversion controller 9, and the combustion tail gas after waste heat recovery is divided into two parts, the first part is used as product gas for oxygen-enriched combustion carbon capture, and the second part is returned to the reflux gas inlet 12 as reflux gas, enters the combustion furnace interlayer 4, and is injected into the combustion furnace cavity 3 through the hole 5 provided in the furnace wall inner shell 2;

[0063] Among them, along the direction from outside to inside, the hole 5 is inclined upward, so that the reflux gas entering the combustion furnace interlayer 4 is sprayed into the combustion furnace cavity 3 along the oblique upward direction; relative to the horizontal plane, the central axis of the hole 5 is inclined upward at an angle of 60 degrees; along the radial direction, the radial deflection angle of the central axis of the hole 5 is 60 degrees, so that the reflux gas entering the combustion furnace interlayer 4 forms a swirl; the hole shape of the hole is a conical hole, and along the direction from outside to inside, the aperture of the conical hole decreases, the large end diameter of the conical hole is 20mm, and the small end diameter of the conical hole is 15mm; the arrangement of the holes is an equilateral triangle, and the center distance between two adjacent holes is 5 times the large end diameter of the conical hole;

[0064] On the outside of the furnace wall shell 1, the mixed feed port 13 is formed by the fuel feed port 14 and the oxygen-rich gas inlet 15. The fuel feed port 14 is used to introduce fuel, and the oxygen-rich gas inlet 15 is used to introduce oxygen-rich gas.

[0065] A heat exchanger 6 is provided at the top of the combustion furnace inner cavity 3, for achieving heat exchange between the combustion exhaust gas and the fluid flowing inside the heat exchanger 6, so as to recover part of the heat of the combustion exhaust gas;

[0066] The diversion controller 9 includes a diversion control valve; a blower 10 is arranged on the pipeline for the reflux gas to return to the combustion furnace interlayer 4, and a buffer tank 11 is arranged at the outlet of the blower 10.

[0067] Comparative Example 1

[0068] This comparative example provides a common combustion furnace, which differs from Example 1 in that an inner shell of the furnace wall is no longer provided, so that there is no interlayer structure of the combustion furnace, and a part of the combustion exhaust gas is no longer extracted as reflux gas.

[0069] For the combustion furnaces described in the above embodiment and the comparative example, oxygen-enriched combustion is performed as follows: biomass solid fuel made of straw is selected, and the oxygen-enriched gas is 50% oxygen and 50% nitrogen, and oxygen-enriched combustion is performed. After the oxygen-enriched combustion is stable, 5 temperature measurement points are uniformly selected on the outside of the inner shell of the furnace wall to measure the temperature and obtain the average outside temperature, and the carbon dioxide content of the product gas is measured. The relevant results are summarized in Table 1.

[0070] Table 1

[0071]

[0072]

[0073] Note: “ / ” indicates no related structure setting.

[0074] From Table 1, we can see the following points:

[0075] (1) The present invention provides a CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, wherein a portion of the combustion exhaust gas is extracted as reflux gas and enters the combustion furnace interlayer and is injected into the combustion furnace cavity through holes opened in the furnace wall inner shell. The reflux gas flows along the furnace wall in the combustion furnace cavity to form a swirl, which serves as an air film insulation layer to reduce the temperature increase of the furnace wall caused by the oxygen-rich combustion reaction in the combustion furnace cavity. The outer temperature of the furnace wall inner shell can be reduced to below 100°C. At the same time, after the combustion exhaust gas is repeatedly refluxed, the carbon dioxide concentration in the combustion exhaust gas is continuously increased, thereby achieving the enrichment of carbon dioxide in the product gas, and the carbon dioxide concentration in the exhaust gas can be increased to more than 40%;

[0076] (2) Comparing Example 1 with Examples 2, 3, and 4, since the upward inclination angle of the holes of the furnace wall inner shell in Examples 2 and 3 is smaller and is not within the range of 30-60 degrees, the swirl formed by the reflux gas in the combustion furnace cavity is weaker, the insulation effect of the air film insulation layer is reduced, and the temperature outside the furnace wall inner shell is slightly increased. Since the upward inclination angle of the holes of the furnace wall inner shell in Example 4 is larger and is not within the range of 30-60 degrees, although the average value of the temperature outside the furnace wall inner shell is basically unchanged, the temperature outside the furnace wall inner shell is uneven and the temperature difference is large;

[0077] (3) Comparing Example 1 with Example 5, since Example 5 reduces the radial deflection angle of the hole of the furnace wall inner shell to 55 degrees, which is not within the range of 60-85 degrees, the degree of swirl formed by the reflux gas adhering to the wall is weak, the insulation effect of the air film insulation layer is reduced, and the temperature outside the furnace wall inner shell is uneven, and the temperature difference is large;

[0078] (4) Comparing Example 1 with Example 6, since Example 6 changes the conical hole into a single circular hole, the air flow velocity from outside to inside is weakened, resulting in a weak swirl formed by the return gas in the combustion furnace cavity, and the insulation effect of the air film insulation layer is reduced, and the temperature of the outer side of the inner shell of the furnace wall is slightly increased;

[0079] (5) Comparing Example 1 with Comparative Example 1, since Comparative Example 1 no longer has an inner shell of the furnace wall, there is no structure of a combustion furnace interlayer, and a portion of the combustion exhaust gas is no longer extracted as reflux gas, resulting in the outer shell of the furnace wall being directly subjected to the high temperature of oxygen-rich combustion. The outer temperature of the inner shell of the furnace wall is above 200°C, and the concentration of carbon dioxide in the product gas is only 36%.

[0080] The present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0081] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0082] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0083] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture, characterized in that: It comprises a furnace wall outer shell, a furnace wall inner shell is arranged inside the furnace wall outer shell, a combustion furnace inner cavity is formed inside the furnace wall inner shell, and a combustion furnace interlayer is formed between the furnace wall inner shell and the furnace wall outer shell; holes are provided on the sides of the furnace wall inner shell, and the combustion furnace inner cavity and the combustion furnace interlayer are connected through the holes provided in the furnace wall inner shell; A mixing feed port is provided at the bottom of the furnace wall shell for passing a mixture of fuel and oxygen-rich gas into the inner cavity of the combustion furnace; a combustion exhaust gas discharge port is provided at the top of the furnace wall shell, and the combustion exhaust gas discharge port is connected to the inlet of the waste heat recovery device, and is used to discharge the combustion exhaust gas in the inner cavity of the combustion furnace and introduce it into the waste heat recovery device; A reflux gas inlet is also provided at the bottom of the furnace wall shell; the outlet of the waste heat recovery device is connected to the diversion controller, and the combustion exhaust gas after waste heat recovery is divided into two parts, the first part is used as product gas for oxygen-enriched combustion carbon capture, and the second part is returned to the reflux gas inlet as reflux gas, enters the combustion furnace interlayer, and is injected into the combustion furnace cavity through the holes provided in the furnace wall inner shell.

2. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 1, characterized in that: In the direction from outside to inside, the holes are inclined upward, so that the reflux gas entering the combustion furnace interlayer is sprayed into the combustion furnace cavity in an oblique upward direction; Preferably, relative to the horizontal plane, the central axis of the hole is inclined upward at an angle of 30-60 degrees.

3. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 1 or 2, characterized in that: In the radial direction, the radial deviation angle of the central axis of the hole is 60-85 degrees, so that the return gas entering the combustion furnace interlayer forms a swirl.

4. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 2 or 3, characterized in that: The hole shape is a tapered hole, and the diameter of the tapered hole decreases from the outside to the inside. The diameter of the large end of the tapered hole is 3-20 mm, and the diameter of the small end of the tapered hole is 2-15 mm.

5. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 2 or 3, characterized in that: The holes are arranged in a regular triangle or a square, and the center distance between two adjacent holes is 1.5-10 times the diameter of the hole.

6. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 1, characterized in that: On the outside of the furnace wall shell, the mixed feed inlet is formed by the merger of a fuel feed inlet and an oxygen-rich gas inlet, the fuel feed inlet is used for introducing fuel, and the oxygen-rich gas inlet is used for introducing oxygen-rich gas.

7. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 1, characterized in that: A heat exchanger is arranged at the top of the inner cavity of the combustion furnace to realize heat exchange between the combustion exhaust gas and the fluid flowing inside the heat exchanger, so as to recover part of the heat of the combustion exhaust gas.

8. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 1, characterized in that: The flow splitter controller includes a flow splitter control valve.

9. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 1, characterized in that: A blower is installed on the pipeline for the reflux gas to return to the combustion furnace interlayer.

10. The CO2-rich flue gas injection insulated combustion furnace for oxygen-rich combustion carbon capture according to claim 9, characterized in that: A buffer tank is arranged at the outlet of the blower.

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