A burner applied to an SOFC system

Abstract

The present invention relates to the technical field of burners, and specifically discloses a burner applied to an SOFC system, which includes a first pipe body and a second pipe body. A first cavity is provided on the pipe wall of the first pipe body; the second pipe body is installed inside the first pipe body, and a second cavity is provided on the pipe wall of the second pipe body; wherein, a mixing cavity is provided between the pipe wall of the first pipe body and the pipe wall of the second pipe body; a plurality of first air inlets and a plurality of first air outlets are respectively formed on the first cavity, and the first air outlets are communicated with the mixing cavity; a plurality of second air inlets and a plurality of second air outlets are formed on the second cavity, and the second air outlets are communicated with the mixing cavity. The burner of the present invention can ensure stable flow and uniform mixing of fuel gas and air.

Description

Technical Field

[0001] The present invention relates to the technical field of burners, and particularly to a burner applied to an SOFC system. Background Art

[0002] A solid oxide fuel cell (SOFC) is a power generation method whose energy conversion efficiency is not limited by the Carnot cycle. It has the advantages of high efficiency, safety, and wide application range, and is currently receiving more and more attention. The electrical conversion efficiency of a solid fuel cell can reach more than 65%, and it has broad application prospects in the fields of distributed energy ships and vehicle power energy.

[0003] As the core component of the thermal balance system in a solid oxide fuel cell, the burner is a difficult point in the design of a solid oxide fuel cell system. During the system heating-up stage, the burner serves as the heat source of the system to achieve the overall heating of the system, so that the stack meets the requirements of the power generation working conditions; during the power generation working conditions of the system, the burner burns the tail gas of the stack to achieve a fuel utilization rate of more than 85% for the system. The gas components during the heating-up stage of the SOFC system are variable, and different heating-up stages have different excess air coefficients. The switching between working conditions causes unstable combustion due to fluctuations in the gas composition, affecting the overall operation of the system; during the power generation operation stage of the system, since the gas components entering the burner are the tail gas that has not reacted sufficiently in the stack, the calorific value of the anode gas is very low, and the oxygen component in the cathode gas is less than 16%. Therefore, how to achieve uniform and stable gas components, small flow fluctuations, and ensure full and stable combustion of the gas in the burner is a difficult point in the structural design of the burner system.

[0004] However, in the existing structure of burners applicable to SOFC systems, air and gas are directly introduced into the mixing chamber through pipelines from the air inlet. Hereby, unstable phenomena such as mutual disturbance will occur at the entrance and inside of the mixing chamber for the two gases, resulting in large fluctuations in gas flow rate, poor stability, and uneven mixing of the two gases in the chamber. As a result, local overheating of components will occur due to excessive local gas concentration during the subsequent combustion process, and the wall overheating problem will lead to the failure of the burner structure. Therefore, achieving uniform distribution of gas and air in the burner is a prerequisite for ensuring stable combustion.

[0005] Moreover, due to the requirements of the SOFC system for the pressure loss of the burner structure, the pressure loss of the gas part distribution and the air part distribution of the burner cannot exceed 1000 Pa. The limiting conditions of the burner structure pressure loss affect the design requirements for the uniform distribution of gas flow, thus causing certain difficulties in the setting of the flow distribution structure and the design of the gas and air mixing structure of the burner. Summary of the Invention

[0006] The object of the present invention is to provide a burner applied to an SOFC system, which can ensure stable flow rates of fuel gas and air and uniform mixing.

[0007] To solve the above technical problems, the present invention provides a burner applied to an SOFC system, including a first tube body and a second tube body. A first cavity is provided on the tube wall of the first tube body; the second tube body is installed inside the first tube body, and a second cavity is provided on the tube wall of the second tube body; wherein, a mixing cavity is provided between the tube walls of the first tube body and the second tube body; a plurality of first air inlets and a plurality of first air outlets are respectively provided on the first cavity, and the first air outlets are communicated with the mixing cavity; a plurality of second air inlets and a plurality of second air outlets are provided on the second cavity, and the second air outlets are communicated with the mixing cavity.

[0008] Preferably, the first cavity includes a first top plate and a first cavity plate. The first top plate is installed on the first cavity plate, and the first cavity plate, the first top plate and the tube wall of the first tube body form a sealed first cavity; the first air inlets are provided on the first top plate.

[0009] Preferably, the first cavity plate is sleeved outside the first tube body, and the first air outlets are provided on the first tube body.

[0010] Preferably, the first cavity plate is arranged inside the first tube body, and the first air outlets are provided on the first cavity plate.

[0011] Preferably, the second cavity includes a second top plate and a second cavity plate. The second top plate is installed on the second cavity plate, and the second cavity plate, the second top plate and the tube wall of the second tube body form a sealed second cavity. The second air inlets are provided on the second top plate.

[0012] Preferably, the second cavity plate is sleeved outside the second tube body, and the second air outlets are provided on the second cavity plate.

[0013] Preferably, the second cavity plate is arranged inside the second tube body, and the second air outlets are provided on the second tube body.

[0014] Preferably, the first top plate and the second top plate are connected by a third top plate to form a top plate. The top plate is an integrally formed structure, and the tube wall of the first tube body, the tube wall of the second tube body and the third top plate form a mixing cavity.

[0015] Preferably, the height of the second air outlets is greater than the height of the first air outlets.

[0016] Preferably, the aperture of the first air outlet is 1-6 mm; the aperture of the second air outlet is 2-8 mm. More preferably, the aperture of the first air outlet is 4-6 mm, which can be 4 mm, 5 mm, and 6 mm; the aperture of the second air outlet is 6-8 mm, which can be 6 mm, 7 mm, and 8 mm.

[0017] Preferably, the first air outlets are arranged in two rows, and the two rows of the first air outlets are arranged staggeredly; the second air outlets are arranged in multiple rows.

[0018] Preferably, the distance between the two rows of the first air outlets is 4-12 mm; the distance between two adjacent first air outlets in the same row is 8-14 mm. More preferably, the distance between the two rows of the first air outlets is 10-12 mm, which can be 10 mm, 11 mm, and 12 mm; the distance between two adjacent first air outlets in the same row is 12-14 mm, which can be 12 mm, 13 mm, and 14 mm.

[0019] Preferably, the distance between two adjacent rows of the second air outlets is 4-16 mm; the distance between two adjacent second air outlets in the same row is 4-16 mm. More preferably, the distance between two adjacent rows of the second air outlets is 14-16 mm, which can be 14 mm, 15 mm, and 16 mm, and the distance between two adjacent second air outlets in the same row is 12-14 mm, which can be 12 mm, 13 mm, and 14 mm.

[0020] Preferably, the ratio of the distance between the two rows of the first air outlets to the aperture of the first air outlet is (1-5):1, and the ratio of the distance between two adjacent first air outlets in the same row to the aperture of the first air outlet is (1-4):1; the ratio of the distance between two adjacent rows of the second air outlets to the aperture of the second air outlet is (1-4):1, and the ratio of the distance between two adjacent second air outlets in the same row to the aperture of the second air outlet is (1-5):1.

[0021] The present invention has the following beneficial effects:

[0022] The burner applied to the SOFC system in the present invention is provided with a first cavity and a second cavity. The first cavity is provided with a first air inlet and a first air outlet for introducing fuel gas and uniformly introducing the fuel gas into the mixing cavity. The second cavity is also provided with a second air inlet and a second air outlet for introducing air and uniformly introducing the air into the mixing cavity, so that the flow rates of the fuel gas and the air are stable and uniformly mixed. The flow rate fluctuations of the fuel gas and the air are controlled within 10%, and the partial pressure losses of the fuel gas and the air do not exceed 1000 Pa, ensuring the uniform mixing of the fuel gas and the air and avoiding the occurrence of local overheating of components and the failure of the burner structure caused by too high local fuel gas concentration during the subsequent combustion process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the burner applied to the SOFC system provided by an embodiment of the present invention;

[0024] Figure 2 is an exploded view of the burner applied to the SOFC system provided by an embodiment of the present invention;

[0025] Figure 3 is a schematic internal structure diagram of the burner applied to the SOFC system provided by an embodiment of the present invention;

[0026] Figure 4 is a schematic structural diagram of the top plate of the burner applied to the SOFC system provided by an embodiment of the present invention;

[0027] Figure 5 is a sectional view of the burner applied to the SOFC system provided by an embodiment of the present invention.

[0028] Reference numerals: 1, first pipe body; 101, first air outlet; 2, first cavity; 201, first cavity plate; 3, second pipe body; 4, second cavity; 401, second cavity plate; 402, second air outlet; 5, top plate; 501, first air inlet; 502, second air inlet; 503, first top plate; 504, second top plate; 505, third top plate; 6, intake pipe; 7, mixing cavity; 8, connecting rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0030] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application 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 therefore should not be construed as a limitation to the present application.

[0031] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0032] See Figures 1 to 3 and Figure 5 A burner applied to an SOFC system according to a preferred embodiment of the present invention includes a first tube body 1 and a second tube body 3. A first cavity 2 is provided on the tube wall of the first tube body 1; the second tube body 3 is installed inside the first tube body 1, and a second cavity 4 is provided on the tube wall of the second tube body 3; wherein, a mixing cavity 7 is provided between the tube walls of the first tube body 1 and the second tube body 3; a plurality of first air inlets 501 and a plurality of first air outlets 101 are respectively opened on the first cavity 2, and the first air outlets 101 communicate with the mixing cavity 7; a plurality of second air inlets 502 and a plurality of second air outlets 402 are opened on the second cavity 4, and the second air outlets 402 communicate with the mixing cavity 7.

[0033] It should be noted that the first tube body 1 and the second tube body 3 are connected by a plurality of connecting rods 8, and the centers of the first tube body 1 and the second tube body 3 are located on the same vertical line. The high-temperature inlet air temperature has relatively high requirements for the selection of burner materials. The material used for the burner of the present invention is a high-temperature resistant nickel-based alloy, and the highest temperature it can withstand reaches 1200 °C.

[0034] Based on the above solution, the working principle of the burner applied to the SOFC system in the preferred embodiment of the present invention is as follows: The fuel gas enters the first cavity 2 through the first air inlet hole 501, and enters the mixing cavity 7 through the uniform diversion of the first air outlet hole 101; the air enters the second cavity 4 through the second air inlet hole 502, and then enters the mixing cavity 7 through the uniform diversion of the second air outlet hole 402. Finally, the fuel gas and the air are mixed in the mixing cavity 7. Due to the diversion effect of the first air outlet hole 101 and the second air outlet hole 402, the flow rates of the two gases, namely the fuel gas and the air, are uniform and stable, and they can be uniformly mixed in the mixing chamber, ensuring the uniformity and stability of the gas composition. The uniformly mixed gas reacts fully, and the waste gas generated after the reaction is discharged through the burner outlet.

[0035] As a preferred solution, the first cavity 2 includes a first top plate 503 and a first cavity plate 201. The first top plate 503 is installed on the first cavity plate 201. The first cavity plate 201, the first top plate 503 and the tube wall of the first tube body 1 form a sealed first cavity 2; the first air inlet hole is opened on the first top plate 503.

[0036] Specifically, the first cavity 2 is composed of the first cavity plate 201, the first top plate 503 and the first tube body 1, which has a simple structure, is convenient and fast to assemble, and is also convenient for subsequent maintenance and replacement.

[0037] As a preferred solution, the first cavity plate 201 is sleeved outside the first tube body 1, and the first air outlet hole 101 is opened on the first tube body 1.

[0038] As a preferred solution, the first cavity plate 201 is arranged inside the first tube body 1, and the first air outlet hole 101 is opened on the first cavity plate 201.

[0039] As a preferred solution, the second cavity 4 includes a second top plate 504 and a second cavity plate 504. The second top plate 504 is installed on the second cavity plate 401. The second cavity plate 401, the second top plate 504 and the tube wall of the second tube body 3 form a sealed second cavity 4, and the second air inlet hole is opened on the second top plate 504.

[0040] Specifically, the second cavity 4 is composed of the second cavity plate 401, the second top plate 504 and the second tube body 3, which has a simple structure, is convenient and fast to assemble, and is also convenient for subsequent maintenance and replacement.

[0041] As a preferred solution, the second cavity plate 401 is sleeved outside the second tube body 3, and the second air outlet hole 402 is opened on the second cavity plate 401.

[0042] As a preferred solution, the second cavity plate 401 is disposed inside the second tube body 3, and the second air outlet 402 is opened on the second tube body 3.

[0043] It should be noted that, in summary, there are four combination cases for the first cavity 2 and the second cavity 4 of the burner of the present invention. Specifically, they include:

[0044] The first case: the first cavity plate 201 is disposed outside the first tube body 1, and the second cavity plate 401 is disposed outside the second tube body 3; the first air outlet 101 is opened on the first tube body 1; the second air outlet 402 is opened on the second cavity plate 401;

[0045] The second case: the first cavity plate 201 is disposed inside the first tube body 1, and the second cavity plate 401 is disposed outside the second tube body 3; the first air outlet 101 is opened on the first cavity plate 201; the second air outlet 402 is opened on the second cavity plate 401;

[0046] The third case: the first cavity plate 201 is disposed inside the first tube body 1, and the second cavity plate 401 is disposed inside the second tube body 3; the first air outlet 101 is opened on the first cavity plate 201; the second air outlet 402 is opened on the second tube body 3;

[0047] The fourth case: the first cavity plate 201 is disposed outside the first tube body 1, and the second cavity plate 401 is disposed inside the second tube body 3; the first air outlet 101 is opened on the first tube body 1; the second air outlet 402 is opened on the second tube body 3.

[0048] See Figure 4 , as a preferred solution, the first top plate 503 and the second top plate 504 are connected to form a top plate 5 through a third top plate 505. The top plate 5 is an integrally formed structure. The wall of the first tube body 1, the wall of the second tube body 3, and the third top plate form a mixing cavity 7. Specifically, the first top plate 503 and the second top plate 504 are connected into an integrally formed top plate 5 through the third top plate 505, which simplifies the overall structure and makes the overall structure assembly more convenient and simple.

[0049] As a preferred solution, the height of the second air outlet hole 402 is greater than the height of the first air outlet hole 101. Specifically, the height of the second air outlet hole 402 being greater than the height of the first air outlet hole 101 can prevent air from entering the first cavity 2 through the first air outlet hole 101 via the second air outlet hole 402 and causing flashback. Moreover, as a cooling gas under high-temperature conditions, the air can prevent the high temperature generated by the combustion of the gas in the mixing cavity 7 from causing high-temperature corrosion to the top plate 5 above the first air outlet hole 101.

[0050] As a preferred solution, the aperture of the first air outlet hole 101 is 1 - 6 mm; the aperture of the second air outlet hole 402 is 2 - 8 mm. More preferably, the aperture of the first air outlet hole 101 is 4 - 6 mm, which can be 4 mm, 5 mm, and 6 mm; the aperture of the second air outlet hole 402 is 6 - 8 mm, which can be 6 mm, 7 mm, and 8 mm.

[0051] As a preferred solution, the first air outlet holes 101 are arranged in two rows, and the two rows of the first air outlet holes 101 are arranged staggeredly; the second air outlet holes 402 are arranged in multiple rows. Specifically, the two rows of the first air outlet holes 101 are arranged staggeredly because after the combustion of the gas released at the first air outlet holes 101 in the upper row consumes air, it will cause insufficient gas oxygen for the lower row of gas, resulting in reduced combustion efficiency and local hot spots due to gas surplus. Therefore, the gas holes in the two rows need to be arranged staggeredly to ensure sufficient oxygen ratio for each gas hole.

[0052] As a preferred solution, the distance between the two rows of the first air outlet holes 101 is 4 - 12 mm; the distance between two adjacent first air outlet holes 101 in the same row is 8 - 14 mm. More preferably, the distance between the two rows of the first air outlet holes 101 is 10 - 12 mm, which can be 10 mm, 11 mm, and 12 mm; the distance between two adjacent first air outlet holes 101 in the same row is 12 - 14 mm, which can be 12 mm, 13 mm, and 14 mm.

[0053] Specifically, the first air outlet holes 101 are distributed in 2 rows, with 50 in each row, and the aperture is 4 mm; the perimeter of the first cavity 2 is 600 mm, and the left and right holes are evenly distributed according to the perimeter of the chamber annular contour. The left and right hole distances are 12 mm, and the upper and lower holes are staggeredly and evenly arranged, with the upper and lower hole distances being 10 mm.

[0054] As a preferred solution, the distance between adjacent two rows of the second air outlet holes 402 is 4 - 16 mm; the distance between adjacent two of the second air outlet holes 402 in the same row is 4 - 16 mm. More preferably, the distance between adjacent two rows of the second air outlet holes 402 is 14 - 16 mm, which can be 14 mm, 15 mm and 16 mm, and the distance between adjacent two of the second air outlet holes 402 in the same row is 12 - 14 mm, which can be 12 mm, 13 mm and 14 mm.

[0055] Specifically, the second air outlet holes 402 are distributed in 3 rows and 128 columns, the hole diameter is 6 mm, the perimeter of the second cavity 4 is 1792 mm, the columns are equally spaced according to the perimeter of the chamber annular contour, the left - right hole distance is 14 mm, and the up - down hole distance is 12 mm.

[0056] As a preferred solution, the ratio of the distance between two rows of the first air outlet holes 101 to the hole diameter of the first air outlet holes 101 is (1 - 5):1, and the ratio of the distance between adjacent two of the first air outlet holes 101 in the same row to the hole diameter of the first air outlet holes 101 is (1 - 4):1; the ratio of the distance between adjacent two rows of the second air outlet holes 402 to the hole diameter of the second air outlet holes 402 is (1 - 4):1, and the ratio of the distance between adjacent two of the second air outlet holes 402 in the same row to the hole diameter of the second air outlet holes 402 is (1 - 5):1.

[0057] Furthermore, the influence of the distance and hole diameter of the first air outlet holes 101 on the flow rate fluctuation and pressure loss is tested, and the test results are shown in Table 1:

[0058] Table 1

[0059]

[0060] Furthermore, the influence of the distance and hole diameter of the second air outlet holes 402 on the flow rate fluctuation and pressure loss is tested, and the test results are shown in Table 2:

[0061] Table 2

[0062]

[0063]

[0064] The working principle of the present invention is as follows: The fuel gas enters the first cavity 2 through the first air inlet hole 501, and enters the mixing cavity 7 through the uniform flow distribution of the first air outlet hole 101; the air enters the second cavity 4 through the second air inlet hole 502, and then enters the mixing cavity 7 through the uniform flow distribution of the second air outlet hole 402. Finally, the fuel gas and the air are mixed in the mixing cavity 7. Due to the flow distribution of the first air outlet hole 101 and the second air outlet hole 402, the flow rates of the two gases, namely the fuel gas and the air, are uniform and stable, and they can be uniformly mixed in the mixing chamber, ensuring the uniformity and stability of the gas composition. The uniformly mixed gas reacts fully, and the waste gas generated after the reaction is discharged through the burner outlet.

[0065] In summary, the preferred embodiment of the present invention provides a burner applied to an SOFC system. Compared with the prior art:

[0066] The burner applied to the SOFC system of the present invention is provided with a first cavity 2 and a second cavity 4. The first cavity 2 is provided with a first air inlet hole 501 and a first air outlet hole 101 for introducing fuel gas and uniformly introducing the fuel gas into the mixing cavity 7. The second cavity 4 is also provided with a second air inlet hole 502 and a second air outlet hole 402 for introducing air and uniformly introducing the air into the mixing cavity 7, so that the flow rates of the fuel gas and the air are stable and uniformly mixed; the fluctuation of the flow rate is controlled within 10%, and the partial pressure loss of the fuel gas and the partial pressure loss of the air shall not exceed 1000 Pa, ensuring the uniformity of the fuel gas and the air, and avoiding the occurrence of local overheating of components and the failure of the burner structure caused by too high local fuel gas concentration during the subsequent combustion process.

[0067] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A burner applied to an SOFC system, characterized in that: Comprising: A first tube body, on the tube wall of the first tube body, a first cavity is provided; A second tube body, the second tube body is installed inside the first tube body, and on the tube wall of the second tube body, a second cavity is provided; Wherein, a mixing cavity is provided between the tube wall of the first tube body and the tube wall of the second tube body; a plurality of first air inlets and a plurality of first air outlets are respectively opened on the first cavity, and the first air outlet is communicated with the mixing cavity; a plurality of second air inlets and a plurality of second air outlets are opened on the second cavity, and the second air outlet is communicated with the mixing cavity; The first cavity includes a first top plate and a first cavity plate, the first top plate is installed on the first cavity plate, and the first cavity plate, the first top plate and the tube wall of the first tube body form a sealed first cavity; the first air inlet is opened on the first top plate; The second cavity includes a second top plate and a second cavity plate, the second top plate is installed on the second cavity plate, and the second cavity plate, the second top plate and the tube wall of the second tube body form a sealed second cavity, and the second air inlet is opened on the second top plate; The height of the second air outlet is greater than the height of the first air outlet.

2. The burner applied to the SOFC system according to claim 1, characterized in that : The first cavity plate is sleeved outside the first tube body, and the first air outlet is opened on the first tube body.

3. The burner applied to the SOFC system according to claim 1, characterized in that : The first cavity plate is arranged inside the first tube body, and the first air outlet is opened on the first cavity plate.

4. The burner applied to the SOFC system according to claim 1, characterized in that : The second cavity plate is sleeved outside the second tube body, and the second air outlet is opened on the second cavity plate.

5. The burner applied to the SOFC system according to claim 1, characterized in that : The second cavity plate is arranged inside the second tube body, and the second air outlet is opened on the second tube body.

6. The burner applied to the SOFC system according to claim 1, characterized in that : The first top plate and the second top plate are connected into a top plate through a third top plate, the top plate is an integrally formed structure, and the tube wall of the first tube body, the tube wall of the second tube body and the third top plate form a mixing cavity.

7. The burner applied to the SOFC system according to claim 1, characterized in that : The first air outlets are arranged in two rows, and the two rows of first air outlets are arranged staggeredly; the second air outlets are arranged in multiple rows.

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