Flame tube cooling structure

Abstract

The invention relates to the field of flame tubes of gas turbines, in particular to a flame tube cooling structure. Comprising an inner cylinder and an outer cylinder arranged outside the inner cylinder in a sleeving mode, at least one cooling water partition plate is arranged on the inner wall of the outer cylinder in the circumferential direction, the inner wall of the outer cylinder is divided into a plurality of cavities through the cooling water partition plates, and an inlet and an outlet for cooling water to enter and exit are formed in each cavity in the axial direction; the cooling structure provided by the invention is simple, so that the scheme provided by the invention is easy to implement and relatively low in processing cost, thereby having wide popularization and application prospects in gas turbines, being applicable to both large industrial equipment and small combustion systems, and being wide in applicability.

Description

Technical Field

[0001] The invention relates to the field of flame tubes of gas turbines, and in particular to a flame tube cooling structure. Background Art

[0002] The gas turbine consists of three major components: the compressor, the combustion chamber, and the turbine. Among them, the highest temperature zone of the gas turbine exists in the combustion chamber. The combustion chamber is a gas combustion component that connects the compressor and the turbine. It converts chemical energy into thermal energy and passes hot air into the turbine to do work. A fuel nozzle is installed at the front end of the combustion chamber. The fuel sprayed from the nozzle and the incoming air burn in the combustion chamber. The combustion temperature can reach more than 2000 degrees Celsius and the pressure can reach 20 atmospheres. The outer cylinder of the combustion chamber is difficult to withstand such high pressure at high temperature. In order to reduce the temperature of the combustion chamber cylinder wall and ensure its strength, a flame tube is usually installed in the combustion chamber to reduce the heat of the outer cylinder so that it mainly bears pressure.

[0003] The flame tube is generally made of high-temperature resistant alloy. The normal working temperature of the current flame tube metal material is below 100 degrees Celsius. Therefore, the flame tube must be cooled, and the rationality of the cooling structure has a great influence on the working life of the flame tube. Otherwise, the flame tube will often have ablation failures, thus affecting the stable operation of the equipment. The traditional flame tube cooling method mainly relies on cooling air for heat dissipation. However, this method fails to fully utilize the waste heat of the flame tube, resulting in energy waste and affecting the economic benefits of the equipment. Summary of the invention

[0004] In response to the problems mentioned in the prior art, the purpose of the present invention is to propose a flame tube cooling structure, aiming to overcome the shortcomings of the prior art. The structure can effectively utilize the waste heat generated during the flame tube cooling process, thereby improving the overall energy utilization efficiency; in addition, the structure can also improve the safety of equipment operation and reduce the risk of failure caused by flame tube ablation.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: The flame tube with a cooling structure of the present invention comprises an inner tube and an outer tube sleeved outside the inner tube, wherein the inner wall of the outer tube is provided with at least one cooling water baffle along the circumferential direction, and the cooling water baffle divides the inner wall of the outer tube into a plurality of chambers, wherein each chamber is provided with an inlet and outlet for cooling water to enter and exit along the axial direction; A channel for gas circulation is provided in the inner tube, and the channel includes a combustion section, a contraction section and an exhaust section connected in sequence. The combustion section is used for gas to flow into the channel, and the exhaust section is used for gas to flow out of the channel, wherein the contraction section is used to transitionally connect the combustion section and the exhaust section.

[0006] As a further improvement of the present invention, the flow directions of the inlet and outlet cooling water of each adjacent chamber are opposite.

[0007] As a further improvement of the present invention, the inlet and outlet include a cooling water forward airflow inlet, a cooling water forward airflow outlet, a cooling water reverse airflow inlet and a cooling water reverse airflow outlet; the cooling water reverse airflow inlet and the cooling water forward airflow outlet are arranged at one end of the outer cylinder, and the cooling water forward airflow inlet and the cooling water reverse airflow outlet are arranged at the other end of the outer cylinder.

[0008] As a further improvement of the present invention, the size of the combustion section of the inner tube is adapted to the inner diameter of the outer tube, and the combustion section is gap-connected to the inner wall of the outer tube.

[0009] As a further improvement of the present invention, the combustion section and the exhaust section are extended and transitioned through an inclined contraction section.

[0010] As a further improvement of the present invention, the ratio of the outer cylinder diameter to the inner cylinder diameter is 1.25:1; The length ratio of the combustion section, the contraction section and the exhaust section is 5:1:1.

[0011] As a further improvement of the present invention, it also includes cooling ribs, which are arranged on the outer peripheral wall of the inner barrel combustion section.

[0012] As a further improvement of the present invention, the cooling ribs are extended and closed along the circumference of the inner cylinder.

[0013] As a further improvement of the present invention, the cooling ribs include first ribs and second ribs, wherein the first ribs and the second ribs are arranged in sequence and spaced apart.

[0014] As a further improvement of the present invention, the first ribs are arranged along the vertical direction, and the second ribs are arranged along the horizontal direction.

[0015] Compared with the prior art, the present invention has achieved the following technical effects: The cooling structure of the present invention is simple, which makes the scheme of the present invention not only easy to implement, but also has a relatively low processing cost, so that the present invention has a broad prospect of promotion and application in gas turbines. It can be used in both large industrial equipment and small combustion systems, and has wide applicability.

[0016] The present invention takes energy utilization into consideration and realizes cooling of the inside of the flame tube by setting up multiple cooling water inlets and outlets. After cooling, the heated cooling water can be used for heating, which not only realizes effective cooling of the flame tube, but also promotes energy conservation and emission reduction, and achieves energy conservation and environmental protection.

[0017] The cooling ribs provided in the present invention realize the effective guidance of cooling water, which not only reduces the temperature of the inner wall of the flame tube, but also greatly improves the efficiency of convective heat transfer, so that the overall temperature of the flame tube is effectively controlled, and ablation failures caused by high temperature are effectively avoided, thereby greatly extending the service life of the flame tube components. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of a flame tube cooling structure of the present invention; Figure 2 It is a schematic diagram of the inner tube structure of a flame tube cooling structure tube of the present invention; Figure 3 This is a schematic diagram of the outer tube structure of a flame tube cooling structure of the present invention; Figure 4 This is a cross-sectional view of the assembly of the inner cylinder and the outer cylinder of a flame tube cooling structure of the present invention; Figure 5 The figure is a schematic diagram of the cooling rib structure of a flame tube cooling structure of the present invention.

[0019] Figure numerals: 1, combustion section; 2, contraction section; 3, exhaust section; 4, cooling ribs; 5, barrel; 6, front end; 7, rear end; 8, cooling water counter-flow inlet; 9, cooling water counter-flow outlet; 10, cooling water forward flow inlet; 11, cooling water forward flow outlet; 12, cooling water partition. DETAILED DESCRIPTION

[0020] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0025] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0026] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0027] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0028] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0029] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] like Figure 1 As shown, the present invention is a flame tube with a cooling structure, comprising an inner tube and an outer tube sleeved outside the inner tube, wherein the inner wall of the outer tube is provided with at least one cooling water dividing baffle 12 along the circumferential direction, and the cooling water dividing baffle 12 divides the inner wall of the outer tube into a plurality of chambers, wherein each chamber is provided with an inlet and outlet for cooling water to enter and exit along the axial direction; a channel for gas circulation is provided in the inner tube, and the channel comprises a combustion section 1, a contraction section 2 and an exhaust section 3 connected in sequence, wherein the combustion section 1 is used for gas to flow into the channel, and the exhaust section 3 is used for gas to flow out of the channel, wherein the contraction section 2 is used for transitionally connecting the combustion section 1 and the exhaust section 3.

[0031] The inner cylinder and the outer cylinder in the embodiment can be separated or assembled. Figure 3 As shown, the outer cylinder is a cylindrical cylinder body 5, and a channel for installing the inner cylinder is provided in the outer cylinder, wherein the channel is arranged through the outer cylinder; in the embodiment, a cooling water partition plate 12 is provided on the inner wall of the outer cylinder, and the length of the cooling water partition plate 12 is the same as the height of the outer cylinder, specifically extending from one end of the outer cylinder to the other end. In this embodiment, there are preferably six cooling water partition plates 12, which can divide the inner wall of the outer cylinder into 6 chambers, but it is not limited to this, and the number of cooling water partition plates 12 can be increased or decreased according to the actual use scenario requirements, thereby increasing or decreasing the number of chambers.

[0032] Implementation example Figure 1 or Figure 2 As shown, the inner tube of this embodiment includes a combustion section 1, a contraction section 2 and an exhaust section 3 which are connected in sequence. The inner tube is arranged in the outer tube. Specifically, the inner tube combustion section 1 is used for the flame tube gas combustion area and has the functions of igniting, maintaining flame and ensuring sufficient reaction of fuel. The inner tube contraction section 2 is the high-temperature flue gas gathering area of ​​the flame tube, which can gather and guide the high-temperature flue gas generated in the flame tube to ensure that the flue gas is guided to the inner tube exhaust section 3 under high temperature. The inner tube exhaust section 3 can discharge the flue gas that has been burned and heat-treated from the flame tube and enter the subsequent flue gas treatment to discharge the flue gas.

[0033] The flow direction of the cooling water inlet and outlet of each adjacent chamber is opposite. The inlet and outlet include a cooling water downstream inlet 10, a cooling water downstream outlet 11, a cooling water reverse flow inlet 8 and a cooling water reverse flow outlet 9; the cooling water reverse flow inlet 8 and the cooling water downstream outlet 11 are arranged at one end of the outer tube, and the cooling water downstream inlet 10 and the cooling water reverse flow outlet 9 are arranged at the other end of the outer tube.

[0034] like Figure 1As shown, the outer cylinder includes a front end 6 and a rear end 7. In this embodiment, an inlet or an outlet is respectively provided at the front end 6 and the rear end 7 of each chamber for the entry or discharge of cooling water. Specifically, Figure 1 As shown, the rear end 7 of one chamber is provided with a cooling water counter-flow inlet 8, and the front end 6 is provided with a cooling water counter-flow outlet 9, while the rear end 7 of the adjacent chamber is provided with a cooling water downstream outlet 11, and the front end 6 is provided with a cooling water downstream inlet 10. The cooling water flows in opposite directions in the adjacent chambers. The cooling water enters from the cooling water counter-flow inlet 8 and flows out from the cooling water counter-flow outlet 9 after heat exchange. The cooling water of the adjacent chamber enters from the cooling water downstream inlet 10 and flows out from the cooling water downstream outlet 11 after heat exchange. The purpose of such a setting is that the cooling water counter-flow can maintain a certain distance between the cooling water and the high-temperature flue gas. There is a large temperature difference, thereby improving the heat exchange efficiency. Because the two flow directions are opposite, the cooling water can still maintain a relatively low temperature at the outlet, thereby more effectively absorbing the heat of the cooled medium. In conjunction with the downstream cooling of the adjacent chamber, when the high-temperature flue gas is large, the downstream cooling can better adapt and reduce the thermal stress caused by excessive temperature gradient. In addition, the design of combining counter-flow cooling and downstream cooling helps to reduce the backflow and dead zone of cooling water in the chamber. By optimizing the flow path of the cooling water, it can be ensured that the cooling water can fully cover the cooled medium and improve the cooling efficiency.

[0035] In the embodiment, the cooling water flows through the outer cylinder body 5 after entering the outer cylinder, and the temperature of the inner cylinder wall is reduced by convective heat exchange with the inner cylinder wall, thereby reducing the temperature of the inner cylinder wall to achieve cooling. In addition, after the cooling water flows through the outer cylinder, its temperature will increase, so that the heated cooling water has a certain thermal energy potential, which can be collected and used in other occasions requiring heating, such as being sent to a heat exchanger. The cooling water after absorbing heat will fully exchange heat with the medium that needs to be heated (such as air, water or other fluids). In this way, the heated cooling water transfers the heat energy it contains to the medium that needs to be heated, thereby realizing the secondary utilization of heat energy, which not only improves energy utilization but also reduces energy consumption.

[0036] The size of the combustion section 1 of the inner cylinder is adapted to the inner diameter of the outer cylinder, and the combustion section 1 is connected to the inner wall of the outer cylinder through a gap; the ratio of the outer cylinder diameter to the inner cylinder diameter is 1.25:1. In the embodiment, cooling water enters the outer cylinder through the inlet and contacts the outer wall of the inner cylinder to achieve cooling and heat dissipation. Figure 4 As shown, when the inner cylinder and the outer cylinder are assembled, a gap for cooling water to flow is provided between the inner cylinder and the outer cylinder. Therefore, the diameter ratio of the inner and outer cylinders is set in the embodiment so that the annular channel between the two has a larger area, thereby providing more heat exchange area between the cooling water and the inner cylinder. The chamber provided in combination can optimize the flow path of the cooling water, ensuring that the cooling water can evenly and effectively cover the surface of the inner cylinder, thereby maximizing the heat exchange effect.

[0037] The combustion section 1 and the exhaust section 3 are extended and transitioned through an inclined contraction section 2; the length ratio of the combustion section 1, the contraction section 2 and the exhaust section 3 is 5:1:1. Figure 4 As shown, in the embodiment, the length ratio of each section structure of the inner tube is limited. The combustion section 1 is relatively long in order to provide sufficient residence time and mixing space for the fuel, to ensure that the fuel can be fully burned and the generated heat can be effectively utilized; and the inclined contraction section 2 helps to reduce the sudden change of the airflow between the combustion section 1 and the exhaust section 3, thereby reducing the airflow resistance. At the same time, the airflow contracts and its flow rate gradually increases, which helps to form a more stable airflow in the exhaust section 3 and reduce turbulence and eddy currents. In the embodiment, there are few restrictions on the inclination angle, and the inclination angle can be set according to actual needs; the exhaust section 3 is shorter than the combustion section 1, which can reduce the exhaust resistance and allow the high-temperature flue gas to be smoothly discharged from the inner tube.

[0038] The cooling rib 4 is also included, and the cooling rib 4 is arranged on the outer peripheral wall of the inner tube combustion section 1. The cooling rib 4 is extended and closed along the circumference of the inner tube. The cooling rib 4 includes a first rib and a second rib, wherein the first rib and the second rib are arranged in sequence and spaced apart. The first rib is arranged in the vertical direction, and the second rib is arranged in the horizontal direction.

[0039] Figure 2 and Figure 5 As shown, in this embodiment, the cooling rib 4 is provided with one circle along the circumferential extension, and may also be provided with more than one circle, and different numbers of circles may be provided according to actual needs or parameter requirements; in the embodiment, the first rib and the second rib have the same structure, both of which are rectangular structures, but the sizes of the two are different, and the arrangement methods are different. In this embodiment, the aspect ratio of the first rib is 16:1, and the aspect ratio of the second rib is 4:1, but the height of the first rib and the second rib is the same. Specifically, the first rib is provided in the vertical direction, and the second rib is provided in the horizontal direction. The vertically provided first rib can guide the cooling water in Disturbance is generated in the vertical direction, which increases the contact area and heat exchange time between the fluid and the fins, and the horizontally arranged second fin can affect the flow of the fluid in the horizontal direction; the first fin and the second fin can cooperate to break the laminar state of the horizontal flow and increase the mixing and disturbance of the fluid in the horizontal direction. Of course, in practical applications, the shape, size and arrangement of the fins can be adjusted according to specific working conditions. For example, in a high-pressure environment, a fin material with high strength and corrosion resistance can be selected; if it is necessary to enhance heat exchange, the number of fins can be increased or the arrangement of the fins can be changed.

[0040] In the embodiment, the first fin and the second fin are spaced apart, which helps to produce an uneven flow path in the cooling water, thereby increasing the flow turbulence. The increase in turbulence can significantly improve the heat transfer coefficient and promote heat transfer. At the same time, two fins with different arrangements are used, and the disturbances generated by different fins in the cooling water are different. Multiple disturbance points can be formed on the flow path. These disturbance points will destroy the laminar structure and turn the flow into turbulent, thereby helping to increase the heat exchange area and heat exchange efficiency between the fluid and the fins, reduce the temperature gradient, and improve the overall heat exchange performance.

[0041] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0042] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A flame tube cooling structure, characterized in that: It comprises an inner cylinder and an outer cylinder sleeved outside the inner cylinder, wherein the inner wall of the outer cylinder is provided with at least one cooling water partition plate along the circumferential direction, and the cooling water partition plate divides the inner wall of the outer cylinder into a plurality of chambers, wherein each chamber is provided with an inlet and outlet for cooling water to enter and exit along the axial direction; A channel for gas circulation is provided in the inner tube, and the channel includes a combustion section, a contraction section and an exhaust section connected in sequence. The combustion section is used for gas to flow into the channel, and the exhaust section is used for gas to flow out of the channel, wherein the contraction section is used to transitionally connect the combustion section and the exhaust section.

2. A flame tube cooling structure according to claim 1, characterized in that: The flow directions of the inlet and outlet cooling water of each adjacent chamber are opposite.

3. A flame tube cooling structure according to claim 2, characterized in that: The inlet and outlet include a cooling water downstream inlet, a cooling water downstream outlet, a cooling water reverse flow inlet and a cooling water reverse flow outlet; The cooling water counter-flow inlet and the cooling water forward flow outlet are arranged at one end of the outer cylinder, and the cooling water forward flow inlet and the cooling water counter-flow outlet are arranged at the other end of the outer cylinder.

4. The flame tube cooling structure according to claim 1, characterized in that: The size of the combustion section of the inner tube is adapted to the inner diameter of the outer tube, and the combustion section is connected with the inner wall gap of the outer tube.

5. A flame tube cooling structure according to claim 4, characterized in that: The combustion section and the exhaust section are extended and transitioned through an inclined contraction section.

6. The flame tube cooling structure according to claim 1, characterized in that: The ratio of the outer cylinder diameter to the inner cylinder diameter is 1.25:1; The length ratio of the combustion section, the contraction section and the exhaust section is 5:1:

1.

7. The flame tube cooling structure according to claim 1, characterized in that: It also includes cooling ribs, which are arranged on the outer peripheral wall of the inner barrel combustion section.

8. A flame tube cooling structure according to claim 7, characterized in that: The cooling ribs are extended and closed along the circumferential direction of the inner cylinder.

9. A flame tube cooling structure according to claim 8, characterized in that: The cooling ribs include first ribs and second ribs, wherein the first ribs and the second ribs are arranged in sequence and spaced apart.

10. A flame tube cooling structure according to claim 9, characterized in that: The first ribs are arranged along the vertical direction, and the second ribs are arranged along the horizontal direction.

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