Dual fuel flame generator

Abstract

The application provides a dual-fuel flame generator, and belongs to the field of combustion equipment.The dual-fuel flame generator comprises a combustion chamber composed of a shell and a flame tube, a swirler installed at the head of the flame tube, a dual-fuel nozzle inserted into the combustion chamber through a through hole reserved on a front cover plate of the combustion chamber, and a nozzle end of the dual-fuel nozzle extending into the swirler through a hole in the swirler, wherein an internal space of the dual-fuel nozzle is provided with a first fuel channel and a second fuel channel which are independent of each other and are in fluid communication with a first fuel pipe and a second fuel pipe; a plurality of first air inlets are arranged on an outer casing of the combustion chamber to allow first air to enter the combustion chamber to form an air film wrapping the flame tube, and the first air reenters the swirler after wrapping the flame tube to mix with the first fuel and the second fuel to form atomized mixed gas; and an igniter is fixedly arranged on the combustion chamber and inserted into the interior of the flame tube through the outer casing of the combustion chamber to ignite the atomized mixed gas.

Description

Technical Field

[0001] This invention belongs to the field of combustion equipment, and particularly relates to a dual-fuel flame generator. Background Technology

[0002] Turbine blades and other high-temperature alloy components are constantly exposed to high-temperature combustion gases (1000℃ and above). Besides the centrifugal loads generated by the high-speed rotation of the blades and the scouring effect of high-speed airflow, blades operating in marine environments are also subject to salt spray corrosion, while those operating in heavily polluted areas are susceptible to sulfide corrosion. High-temperature components such as turbine blades operating in corrosive environments are more prone to oxidation, corrosion, and ablation, leading to blade breakage and other failures, threatening the safe operation of the gas turbine. Furthermore, with the improvement of gas turbine efficiency, turbine inlet temperatures are increasing (currently, advanced gas turbine combustion gas temperatures have reached over 1500℃, and will reach 1700℃ in the future), making the environment for turbine blades even more severe. Therefore, the safety design and testing of high-temperature components such as turbine blades are crucial. Typically, the corrosion resistance evaluation of high-temperature alloys is conducted in a high-temperature oxidation furnace, which, apart from coating the sample surface with a layer of corrosive salt, does not consider the effects of the combustion gas atmosphere, humidity, and dust scouring. The evaluation of anti-oxidation and corrosion coatings such as thermal barrier coatings often uses single fuels such as oxyacetylene and kerosene to verify thermal shock and thermal cycling under thermal gradient and gas scouring effects, without considering the influence of gas composition. Furthermore, with the increasing application of clean energy sources such as natural gas and hydrogen in recent years, hydrogen engines have gained more attention. Therefore, a dedicated flame generator needs to be designed for the reliability evaluation of hydrogen engines. Summary of the Invention

[0003] In view of this, the present invention provides a dual-fuel flame generator, which can provide high-temperature erosion, salt spray corrosion, sulfide corrosion, dust erosion and other environments for mechanical property tests such as high-temperature fatigue and creep. It can also replace the flame generator in the thermal shock test of thermal barrier coatings to realize various high-temperature gas atmospheres such as fuel oil, natural gas and dual fuel.

[0004] According to an embodiment of the present invention, a dual-fuel flame generator is provided, comprising a combustion chamber, a swirler, a dual-fuel nozzle, a first fuel pipe, a second fuel pipe, a plurality of first air inlets, and an igniter.

[0005] The combustion chamber includes a housing consisting of an outer casing of the combustion chamber and a front cover plate of the combustion chamber, and a flame tube located inside the housing.

[0006] The cyclone separator is installed at the head of the flame tube and secured by a cyclone separator cover plate.

[0007] The dual-fuel nozzle is inserted into the combustion chamber through a pre-drilled hole on the front cover plate of the combustion chamber, and the nozzle end of the dual-fuel nozzle extends into the interior of the swirler through the central hole of the swirler. The internal space of the dual-fuel nozzle is provided with a first fuel channel and a second fuel channel that are independent of each other.

[0008] The first fuel pipe and the second fuel pipe are in fluid communication with the internal space of the dual fuel nozzle.

[0009] Multiple first air inlets are located on the outer casing of the combustion chamber. After the first air enters the combustion chamber through the first air inlet, it forms a gas film that surrounds the flame tube. At the same time, the first air surrounding the flame tube flows back and enters the cyclone separator through the air holes on the cyclone separator cover plate, where it mixes with the first fuel and the second fuel. The resulting atomized mixture then enters the flame tube.

[0010] The igniter is fixedly mounted on the combustion chamber, with one end passing through the outer casing of the combustion chamber and inserted into the interior of the flame tube to ignite the atomized mixture.

[0011] In some embodiments, the dual-fuel flame generator further includes an exhaust chamber located downstream of the combustion chamber. The exhaust chamber includes an outer exhaust casing and an outlet section located inside the outer exhaust casing. The outlet section communicates with the flame tube and is provided with a gas outlet for the high-temperature gas generated by the combustion of the atomized mixture.

[0012] In some embodiments, the dual-fuel flame generator further includes a secondary combustion chamber disposed between the combustion chamber and the exhaust chamber. The secondary combustion chamber includes an outer casing for the secondary combustion chamber and a secondary combustion section located inside the outer casing for the secondary combustion chamber. The secondary combustion section communicates with the flame tube and the outlet section. The outer casing for the secondary combustion chamber is provided with multiple second air inlets. Second air enters the secondary combustion section through the second air inlets to ensure complete combustion of the atomized mixture.

[0013] In some embodiments, the discharge chamber is also provided with a brine inlet and / or a dust inlet.

[0014] In some embodiments, the exhaust chamber is also equipped with a thermocouple for monitoring the temperature of the high-temperature gas.

[0015] In some embodiments, the first fuel pipe and the second fuel pipe are arranged perpendicular to each other; the first fuel passage and the second fuel passage are arranged coaxially.

[0016] In some embodiments, the combustion chamber front cover, the combustion chamber outer casing, the secondary combustion chamber outer casing, and the exhaust chamber outer casing are connected by bolts, and the connection is sealed with an asbestos gasket.

[0017] In some implementations, the outlet section adopts a constricted design, with the gas outlet located on the horizontal central axis of the flame tube and the outlet section.

[0018] In some embodiments, the flame tube is divided into a premixing zone, a main combustion zone, and a secondary combustion zone in sequence. The premixing zone adopts a tapered design, the main combustion zone adopts an expanded diameter section design, and the secondary combustion zone has the same diameter as the main combustion zone.

[0019] In some implementations, the cyclone separator is mounted at the head of the flame tube via a flange.

[0020] In some embodiments, the dual-fuel flame generator further includes a fixed support for supporting the combustion chamber.

[0021] In this invention, a dual-fuel nozzle comprising a first fuel channel and a second fuel channel is provided, and fluidly connected to the first fuel pipe and the second fuel pipe respectively, to allow different fuels to be introduced into the dual-fuel nozzle. The dual-fuel nozzle is inserted into the flame tube of the combustion chamber, so that the first fuel and the second fuel enter the combustion chamber through the first fuel channel and the second fuel channel respectively. First air enters the combustion chamber through multiple first air inlets, enveloping the flame tube to form a gas film, cooling the flame tube. Simultaneously, the first air recirculates and enters the cyclone separator through air holes on the cyclone separator cover, mixing with the first fuel and the second fuel entering the cyclone separator to form an atomized mixture. Finally, under the action of an igniter located in the combustion chamber, the atomized mixture is ignited to generate high-temperature combustion gas. The dual-fuel flame generator provided by this invention can ignite different fuels, has strong fuel versatility, and provides different high-temperature and combustion gas environments for test specimens. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the assembly of the dual-fuel flame generator of the present invention;

[0023] Figure 2 for Figure 1 Vertical cross-sectional view of a dual-fuel flame generator;

[0024] Figure 3 for Figure 1 Horizontal cross-sectional view of a dual-fuel flame generator;

[0025] Figure 4 for Figure 3 A magnified view of the connection between the dual-fuel nozzle and the cyclone separator.

[0026] [Attached image labels]

[0027] 1-Combustion chamber, 11-Outer casing of combustion chamber, 12-Front cover of combustion chamber, 13-Flame tube, 131-Premixing zone, 132-Main combustion zone, 133-Secondary combustion zone, 14-Swirl generator, 141-Swirl generator cover, 15-First air inlet, 16-Air hole;

[0028] 2-Dual fuel nozzle, 21-First fuel passage, 22-Second fuel passage;

[0029] 3-First fuel pipe;

[0030] 4-Second fuel pipe;

[0031] 5-Igniter;

[0032] 6-Secondary combustion chamber, 61-Secondary air inlet, 62-Secondary combustion outdoor unit casing, 63-Secondary combustion section;

[0033] 7-Discharge chamber, 71-Salt solution inlet, 72-Thermocouple, 73-Dust inlet, 74-Outdoor discharge unit casing;

[0034] 8-Fixed support;

[0035] 9-bolts

[0036] A - First fuel, B - First air, C - Second air, D - Gas fuel. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0038] Figure 1 This is a schematic diagram of the assembly of the dual-fuel flame generator of the present invention. Figure 2 for Figure 1 Vertical cross-sectional view of a dual-fuel flame generator. Figure 3 for Figure 1 Horizontal cross-sectional view of a dual-fuel flame generator; Figure 4 for Figure 3 A magnified view of the connection between the dual-fuel nozzle and the cyclone separator.

[0039] like Figures 1-3 As shown, the dual-fuel flame generator of the present invention includes: a dual-fuel nozzle 2, a combustion chamber 1, a swirler 14, a first fuel pipe 3, a second fuel pipe 4, multiple first air inlets 15, and an igniter 5.

[0040] Specifically, combustion chamber 1 is a chamber in which fuel (including first fuel A and second fuel) mixes with air to generate high-temperature combustion gas D. The combustion chamber 1 of this invention includes a housing composed of an outer combustion chamber casing 11 and a combustion chamber front cover plate 12, and a flame tube 13 located inside the housing. The outer combustion chamber casing 11 and the combustion chamber front cover plate 12 are connected by bolts 9. To ensure the airtightness of the outer combustion chamber casing 11 and the combustion chamber front cover plate 12, an asbestos gasket is used to seal the connection.

[0041] Combination Figure 4 As shown, the cyclone separator 14 is installed at the head of the flame tube 13 and fixed by the cyclone separator cover plate 141. Specifically, the cyclone separator 14 is provided with a cyclone separator cover plate 141, which is connected to the flange of the flame tube 13 by bolts 9. The cyclone separator 14 is fixed to the head of the flame tube 13 by the flange and fixed by the cyclone separator cover plate 141.

[0042] The dual-fuel nozzle 2 is inserted into the combustion chamber 1 through a pre-reserved through hole on the combustion chamber front cover plate 12, and the nozzle end of the dual-fuel nozzle 2 extends into the swirler 14 through the central hole of the swirler 14. The internal space of the dual-fuel nozzle 2 is provided with a first fuel channel 21 and a second fuel channel 22 that are independent of each other.

[0043] The first fuel pipe 3 and the second fuel pipe 4 are in fluid communication with the internal space of the dual-fuel nozzle 2. Specifically, the first fuel pipe 3 and the second fuel pipe 4 are arranged perpendicularly to each other outside the dual-fuel nozzle 2. The internal space of the dual-fuel nozzle 2 is coaxially provided with a first fuel channel 21 and a second fuel channel 22 (i.e., the dual-fuel nozzle 2 has inner and outer fuel channels). The first fuel pipe 3 is fluidly connected to the first fuel channel 21 inside the dual-fuel nozzle 2, and the second fuel pipe 4 is fluidly connected to the second fuel channel 22 inside the dual-fuel nozzle 2. This allows the first fuel A and the second fuel to be fed into the dual-fuel nozzle 2 through independent channels, ejected from the nozzle end of the dual-fuel nozzle 2, and then enter the interior of the cyclone separator 14 and the flame tube 13 through the central hole of the cyclone separator 14. It should be noted that the arrangement of the first fuel channel 21 and the second fuel channel 22 is not limited to this. Figures 1-4 The arrangement shown is as follows. In other words, the first fuel channel 21 can serve as the inner or outer layer of the dual-fuel nozzle 2, and similarly, the second fuel channel 22 can serve as the outer or inner layer of the dual-fuel nozzle 2.

[0044] Multiple first air inlets 15 are disposed on the outer casing 11 of the combustion chamber. First air B enters the combustion chamber 1 through the first air inlets 15 and forms an air film enveloping the flame tube 13, cooling the flame tube 13. Simultaneously, the first air B enveloping the flame tube 13 flows back and passes through the air holes 16 on the cyclone separator cover plate 141 (e.g., ...). Figure 4(As shown) It enters the cyclone separator 14 for pre-swirl and mixes with the first fuel A and the second fuel. The resulting atomized mixture enters the flame tube 13.

[0045] Igniter 5 is fixedly mounted on combustion chamber 1, and one end of it passes through the outer casing 11 of combustion chamber and is inserted into the interior of flame tube 13 to ignite the atomized mixture.

[0046] In this invention, the first fuel channel 21 and the second fuel channel 22 are respectively fluidly connected to the first fuel pipe 3 and the second fuel pipe 4 to allow different fuels to be introduced into the dual-fuel nozzle 2. The dual-fuel nozzle 2 is inserted into the flame tube 13 of the combustion chamber 1 so that the first fuel and the second fuel enter the combustion chamber 1 through the first fuel channel 21 and the second fuel channel 22 respectively for mixing. First air B enters the combustion chamber 1 through multiple first air inlets 15, enveloping the flame tube 13 to form a gas film and cooling the flame tube 13. Simultaneously, the first air B flows back and enters the cyclone separator 14 through the air holes 16 on the cyclone separator cover plate 141, where it mixes with the first fuel and the second fuel entering the cyclone separator 14 to form an atomized mixture. Finally, the atomized mixture is ignited by the igniter 5 installed in the combustion chamber 1, and the mixture burns to produce high-temperature gas D. The dual-fuel flame generator provided by this invention can ignite different fuels, has strong fuel versatility, and provides different high-temperature (above 1000℃) gas environments for the thermal corrosion study of test pieces. The first type of air, B, is high-pressure air with a pressure of 0.8 MPa to 1 MPa.

[0047] In some embodiments, the first fuel A and the second fuel can be independent and different liquid fuels or gaseous fuels, wherein the liquid fuel can be, for example, methanol, and the gaseous fuel can be, for example, hydrogen, methane, etc.

[0048] In some embodiments, along the fuel flow direction, the flame tube 13 of the present invention is sequentially divided into a premixing zone 131, a main combustion zone 132, and a secondary combustion zone 133. The aforementioned igniter 5 may be located in the main combustion zone 132. The premixing zone 131 adopts a constant-diameter section design (inner diameter 53 mm), the main combustion zone 132 adopts an expanded-diameter section design, and the secondary combustion zone 133 has the same diameter as the main combustion zone 132, but its inner diameter is larger than that of the premixing zone 131. The constant-diameter section design in the premixing zone 131 allows for thorough mixing of the first fuel, the second fuel, and air swirled and mixed by the cyclone separator 14, forming a higher-velocity atomized mixture. Subsequently, the atomized mixture enters the expanded-diameter section of the main combustion zone 132 and is rapidly ignited and combusted by the igniter 5 located in this area, forming a higher-temperature and higher-velocity fuel gas D.

[0049] In some embodiments, the dual-fuel flame generator of the present invention further includes: an exhaust chamber 7, located downstream of the combustion chamber 1, the exhaust chamber 7 including an exhaust outer casing 74 and an outlet section located inside the exhaust outer casing 74. The combustion outer casing 11, the casing of the flame tube 13, and the exhaust outer casing 74 are fixedly connected by bolts 9, and the connection is sealed with an asbestos gasket to ensure airtightness and prevent leakage of the fuel gas D. The outlet section communicates with the flame tube 13 and is provided with a gas outlet for discharging the fuel gas D formed by the combustion of the atomized mixture. The diameter of the gas outlet is approximately 25 mm, which facilitates increasing the gas velocity to form higher temperature and higher velocity fuel gas. The outlet section adopts a tapered design, and the gas outlet is located on the horizontal central axis of the flame tube 13 and the outlet section to discharge the higher temperature and higher velocity fuel gas D from the gas outlet.

[0050] Further as Figures 1-4 As shown, to ensure complete combustion of the atomized mixture and increase the flow rate of the fuel gas D, the dual-fuel flame generator of the present invention further includes a secondary combustion chamber 6 disposed between the combustion chamber 1 and the exhaust chamber 7. The secondary combustion chamber 6 includes a secondary combustion chamber outer casing 62 and a secondary combustion section 63 located inside the secondary combustion chamber outer casing 62. The secondary combustion chamber outer casing 62 is connected to the combustion chamber outer casing 11 and the exhaust chamber outer casing 74 by bolts 9, and the connection is sealed with an asbestos gasket to prevent leakage of the fuel gas D. Further, the secondary combustion chamber outer casing is provided with multiple second air inlets 61. Second air C enters the secondary combustion section 63 through the second air inlets 61. The secondary combustion section 63 is integrated with the flame tube 13 and the outlet section to form a single structure. At this time, the atomized mixture that has not been fully combusted in the flame tube 13 enters the secondary combustion section 63, mixes with the second air C, and combusts to form a higher temperature and higher velocity fuel gas D. This higher temperature and higher velocity fuel gas D is discharged through the outlet section. It should be noted that, in the case where the dual-fuel flame generator also includes a secondary combustion chamber 6, the premixing zone 131 of the flame tube 13 of the present invention adopts an equal diameter section design, the outlet section adopts a constricted design, the main combustion zone 132 adopts an expanded diameter section design, the secondary combustion zone 133 has the same diameter as the secondary combustion section 63, and the igniter 5 is set in the main combustion zone 132 of the flame tube 13, which can also form a gas D with higher temperature and higher speed.

[0051] In some implementations, continue as Figures 1-4As shown, the emission chamber 7 of the present invention is further provided with a salt solution inlet 71 and / or a dust inlet 73. The number of salt solution inlets 71 and / or dust inlets 73 can be one, two, or more, flexibly configured according to actual needs. Preferably, two or more salt solution inlets 71 and / or dust inlets 73 are symmetrically arranged or uniformly distributed. A salt solution (such as sodium chloride solution or sulfate solution) can be transported to the high-temperature fuel gas D through the salt solution inlet 71 by a pump to change the composition of the fuel gas D and achieve high-temperature thermal corrosion. Alternatively, CMAS (calcium oxide-magnesium oxide-alumina-silicate) dust can be transported to the high-temperature fuel gas D through the dust inlet 73 by a gas pump to change the composition of the fuel gas D and achieve dust scouring.

[0052] In some implementations, continue as Figures 1-4 As shown, the discharge chamber 7 is also equipped with a thermocouple 72 for monitoring the temperature of the gas D. The thermocouple 72 used in this invention can be an S-type thermocouple, which can be installed on the upper side of the outlet section and / or inserted into the gas D from the left side of the outlet section to measure the temperature of the gas D in the outlet section and calculate the flow rate of the gas D. If the temperature or flow rate of the gas D does not meet the test requirements, a second air C can be introduced into the secondary combustion chamber 6 to ensure complete combustion of the atomized mixture, thereby increasing the temperature and flow rate of the gas D discharged from the outlet section. The second air C is high-pressure air with a pressure of 0.8 MPa-1 MPa.

[0053] In some implementations, continue as Figures 1-4 As shown, the dual-fuel flame generator of the present invention further includes: a fixed support 8 for supporting the combustion chamber 1.

[0054] In some implementations, the gas outlet of the dual-fuel flame generator is aligned with the test specimen during actual use, providing the test specimen with an environment of thermal gas corrosion, salt spray corrosion, dust erosion, etc., thereby enabling research on high-temperature fatigue, creep, corrosion, etc.

[0055] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-fuel flame generator, characterized in that, include: The combustion chamber includes a housing consisting of an outer casing of the combustion chamber and a front cover plate of the combustion chamber, and a flame tube located inside the housing; A cyclone separator is installed at the head of the flame tube and fixed by a cyclone separator cover plate; The dual-fuel nozzle is inserted into the combustion chamber through a pre-reserved through hole on the front cover plate of the combustion chamber, and the nozzle end of the dual-fuel nozzle extends into the interior of the swirler through the central hole of the swirler. The internal space of the dual-fuel nozzle is provided with a first fuel channel and a second fuel channel that are independent of each other. The first fuel pipe and the second fuel pipe are in fluid communication with the internal space of the dual fuel nozzle; Multiple first air inlets are provided on the outer casing of the combustion chamber. After the first air enters the combustion chamber through the first air inlet, it forms an air film that surrounds the flame tube. At the same time, the first air surrounding the flame tube flows back and enters the cyclone separator through the air hole on the cyclone separator cover plate, where it mixes with the first fuel and the second fuel. The resulting atomized mixture enters the flame tube. An igniter is fixedly mounted on the combustion chamber, with one end passing through the outer casing of the combustion chamber and inserted into the interior of the flame tube to ignite the atomized mixture.

2. The dual-fuel flame generator according to claim 1, characterized in that, The dual-fuel flame generator also includes: The exhaust chamber is located downstream of the combustion chamber. The exhaust chamber includes an outer exhaust casing and an outlet section located inside the outer exhaust casing. The outlet section communicates with the flame tube and is provided with a gas outlet for the high-temperature gas generated by the combustion of the atomized mixture.

3. The dual-fuel flame generator according to claim 2, characterized in that, The dual-fuel flame generator also includes: A secondary combustion chamber is disposed between the combustion chamber and the emission chamber. The secondary combustion chamber includes an outer casing for the secondary combustion chamber and a secondary combustion section located inside the outer casing for the secondary combustion chamber. The secondary combustion section communicates with the flame tube and the outlet section. The outdoor unit casing for secondary combustion is provided with multiple second air inlets. Second air enters the secondary combustion section through the second air inlets to ensure that the atomized mixture is fully combusted.

4. The dual-fuel flame generator according to claim 2 or 3, characterized in that, The discharge chamber is also equipped with: Salt solution inlet and / or dust inlet.

5. The dual-fuel flame generator according to claim 4, characterized in that, The discharge chamber is also equipped with: Thermocouples are used to monitor the temperature of the high-temperature gas.

6. The dual-fuel flame generator according to claim 1 or 5, characterized in that, The first fuel pipe and the second fuel pipe are arranged perpendicular to each other. The first fuel channel and the second fuel channel are arranged coaxially.

7. The dual-fuel flame generator according to claim 2, characterized in that, The combustion chamber front cover, the combustion chamber outer casing, the secondary combustion chamber outer casing, and the exhaust chamber outer casing are connected by bolts, and the connection is sealed with an asbestos gasket.

8. The dual-fuel flame generator according to claim 2, characterized in that, The outlet section adopts a tapering design, and the gas outlet is located on the horizontal central axis of the flame tube and the outlet section; The flame tube is divided into a premixing zone, a main combustion zone, and a secondary combustion zone. The premixing zone adopts a constant diameter section design, the main combustion zone adopts an expanded diameter section design, and the secondary combustion zone has the same diameter as the main combustion zone.

9. The dual-fuel flame generator according to claim 1, characterized in that, The cyclone separator is mounted on the head of the flame tube via a flange.

10. The dual-fuel flame generator according to claim 5, characterized in that, The dual-fuel flame generator also includes: A fixed support is used to support the combustion chamber.

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