A nozzle combustor for use in a combustion chamber of a gas turbine

Abstract

The application discloses the technical field of gas turbine, in particular to a nozzle combustor applied to a combustion chamber of a gas turbine, which aims at solving the problem that the gas turbine is difficult to realize stable low emission combustion under high temperature and wide load working conditions in the prior art, and the cooling efficiency of the nozzle is low; the structure comprises a duty class nozzle, a main combustion class nozzle, a fuel rectifying plate and a nozzle upper cover plate, the main combustion class nozzle is located outside the duty class nozzle; the mixture sprayed by the main combustion class nozzle directly passes through a combustion zone of the nozzle combustor; the fuel rectifying plate and the nozzle upper cover plate are wrapped to form an upper fuel cavity, the duty class nozzle and the main combustion class nozzle are communicated with the combustion zone of the nozzle combustor through the nozzle upper cover plate, and the fuel in the upper fuel cavity exchanges heat by directly contacting the nozzle upper cover plate.

Description

TECHNICAL FIELD

[0001] The application relates to a nozzle combustor applied to a gas turbine combustor and belongs to the technical field of gas turbine combustors. BACKGROUND

[0002] The gas turbine has become an indispensable power source in industrial production due to its high efficiency and cleanliness. With the iteration and update of technology, the gas turbine is continuously developed towards higher efficiency and a wider load adjustment range. How to realize stable and low-emission combustion in a wide load working condition range is an important performance target of the gas turbine combustor.

[0003] Most existing gas turbines adopt the combustor of the dry low nitrogen oxide (Dry Low NOx, DLN) combustion technology. Such a combustor mainly adopts the method of mixing excess air and fuel into lean premixed gas to inhibit the generation of nitrogen oxides. However, when the gas turbine develops to the J level, the temperature level is close to the critical value of the effective working range (1670-1900K) of the DLN. If the temperature is further increased, on the one hand, even if the air and fuel are completely premixed, the nitrogen oxide emission will be greatly increased, and on the other hand, using the conventional swirl premixed combustion mode, there are risks of backfire, self-ignition, thermal acoustic oscillation and the like. Therefore, the dry low nitrogen oxide (Dry Low NOx, DLN) combustion technology cannot meet the development of the gas turbine.

[0004] Compared with the traditional swirl combustor, the micro-premixed combustion technology mixes the air and fuel in a small pipe, improves the gas mixing uniformity, and has a small flame structure and a high gas flow rate. In addition, the pipe diameter has a quenching effect. The micro-premixed combustion technology not only can reduce the NOX emission but also has good anti-backfire capability. However, because there is no swirl structure and the gas flow rate is higher than that of the traditional combustor, the micro-premixed combustion technology has poor stability and is difficult to realize stable combustion in a wide working condition range. Therefore, the swirl combustion and the micro-mixed combustion technology have their own advantages and disadvantages. If the swirl combustion and the micro-mixed combustion can be combined to take the advantages of both, it is a feasible technical solution for the further development of the gas turbine combustor.

[0005] In addition, the upper end surface of the nozzle directly contacts the combustion area, and the temperature of the nozzle end surface is very high. Therefore, the cooling of the nozzle has always been a technical problem. At present, air is basically used as the cooling medium. However, with the development of the gas turbine, the flame temperature and the nozzle end surface temperature are increasingly high, the air inlet temperature is increasingly high, and the contradiction between the cooling efficiency and the two is increasingly large. Therefore, it is urgent to find a new cooling solution. SUMMARY

[0006] The application aims to overcome the deficiencies in the prior art. The existing gas turbine is difficult to realize stable and low-emission combustion under high temperature and wide load working conditions, and the cooling efficiency of the nozzle is low.

[0007] To solve the above technical problems, the present application is realized by using the following technical solutions:

[0008] The application provides a nozzle combustor applied to a combustion chamber of a gas turbine, comprising an air inlet assembly, a fuel inlet pipe, a nozzle body and a flame tube, the air inlet assembly and the nozzle body are coaxially connected, the fuel inlet pipe is arranged in the side wall of the nozzle body in a ring shape, the flame tube is installed at the outlet of the nozzle body, and an internal cylindrical area formed by wrapping the flame tube is a combustion zone of the nozzle combustor.

[0009] The nozzle body comprises a pilot stage nozzle, a main combustion stage nozzle, a fuel straightening plate and a nozzle upper cover plate, the main combustion stage nozzle is located outside the pilot stage nozzle, the mixture sprayed by the main combustion stage nozzle directly passes through the combustion zone of the nozzle combustor, the fuel straightening plate and the nozzle upper cover plate wrap to form an upper fuel chamber, the pilot stage nozzle and the main combustion stage nozzle are both communicated with the combustion zone of the nozzle combustor through the nozzle upper cover plate, and the fuel in the upper fuel chamber exchanges heat by directly contacting the nozzle upper cover plate.

[0010] The mixture sprayed by the pilot stage nozzle moves in a spiral manner.

[0011] Further, the air inlet assembly comprises an air inlet pipe, an air cavity, an air baffle and a baffle support.

[0012] One bottom surface of the air cavity is connected with the nozzle body, the air inlet pipe is coaxially installed on the other bottom surface of the nozzle body, and the air baffle is coaxially installed on the bottom surface of the air cavity where the air inlet pipe is located through the baffle support.

[0013] Further, the nozzle body further comprises a nozzle lower cover plate.

[0014] The nozzle lower cover plate and the fuel straightening plate wrap to form a lower fuel chamber, and the fuel inlet pipe is communicated with the upper fuel chamber.

[0015] Fuel straightening holes are formed in the surface of the fuel straightening plate and pass through the upper fuel chamber and the lower fuel chamber.

[0016] Further, the main combustion stage nozzle is provided in a plurality of forms, and the main combustion stage nozzle penetrates the upper fuel chamber and the lower fuel chamber.

[0017] One end of the main combustion stage nozzle is communicated with the combustion zone of the nozzle combustor through the nozzle upper cover plate, and the other end is communicated with the inside of the air inlet assembly through the nozzle lower cover plate.

[0018] Further, part of the main combustion stage nozzle located in the lower fuel chamber is uniformly provided with main combustion stage fuel inlet holes in the axial direction.

[0019] Further, the on-duty class nozzle is internally provided with a spiral blade, which is fixedly installed on the inner side wall of the on-duty nozzle.

[0020] The structure of the spiral blade is hollow.

[0021] Further, the on-duty class nozzle is uniformly provided with on-duty class fuel inlet holes in the part of the lower fuel cavity in the axial direction.

[0022] Further, the mixture is a mixture of air and fuel.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] 1. The present application cools the nozzle upper cover plate by the fuel gas flow through the upper fuel cavity, while the nozzle upper cover plate reversely heats it, the chemical reaction is strengthened, the combustion gas combustion is promoted, the flame propagation speed is improved, thereby improving the nozzle combustor combustion efficiency and improving the nozzle combustor combustion stability performance.

[0025] 2. The spiral fuel gas sprayed by the on-duty class nozzle can promote the rapid mixing of fuel and air on one hand, and form a backflow area at the nozzle outlet on the other hand, and overall form a mixed flow structure of outer circle rotational flow center jet flow in the combustion area, while the main combustion class nozzle in the outer circle can well play a role in stabilizing the flame, making up for the shortcoming of premixed combustion of rotational flow being easy to backfire, so the present application takes into account the technical advantages of rotational flow combustion and micro-mixed combustion, so as to realize stable and efficient combustion of the nozzle combustor in a wide operating condition range. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 It is an explosion diagram of one embodiment of the present application;

[0027] Fig. 2 It is a whole cross-sectional view of one embodiment of the present application;

[0028] Fig. 3 It is a structure diagram of the main combustion class nozzle of one embodiment of the present application;

[0029] Fig. 4 It is a three-dimensional cross-sectional view of the nozzle body of one embodiment of the present application;

[0030] Fig. 5 It is an air cavity structure schematic diagram of one embodiment of the present application;

[0031] Fig. 6 It is an internal structure diagram of the air inlet assembly of one embodiment of the present application.

[0032] Figure: 1, air intake assembly; 11, air intake pipe; 12, air cavity; 13, air baffle; 14, baffle support; 2, fuel intake pipe; 3, nozzle body; 31, primary stage nozzle; 311, helical blade; 312, primary stage fuel intake hole; 32, main combustion stage nozzle; 321, main combustion stage fuel intake hole; 33, fuel rectification plate; 331, fuel rectification hole; 34, nozzle upper cover plate; 35, upper fuel cavity; 36, nozzle lower cover plate; 37, lower fuel cavity; 4, flame tube. DETAILED DESCRIPTION

[0033] The application will be further described below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the application, and cannot be used to limit the protection scope of the application.

[0034] In the description of the application, it should be noted that unless explicitly defined and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances. EMBODIMENT

[0035] The embodiment discloses a nozzle combustor suitable for gas turbine combustion chamber, which comprises: air intake assembly 1, fuel intake pipe 2, nozzle body 3 and flame tube 4, the air intake assembly 1 and the nozzle body 3 are coaxially connected, the fuel intake pipe 2 is arranged annularly on the side wall of the nozzle body 3, the flame tube 4 is installed at the outlet of the nozzle body 3, and the internal cylindrical area formed by wrapping the flame tube 4 is the combustion zone of the nozzle combustor.

[0036] The nozzle body 3 comprises primary stage nozzle 31, main combustion stage nozzle 32, fuel rectification plate 33 and nozzle upper cover plate 34, the main combustion stage nozzle 32 is located outside the primary stage nozzle 31; the mixture sprayed by the main combustion stage nozzle 32 directly passes through the combustion zone of the nozzle combustor; the fuel rectification plate 33 and the nozzle upper cover plate 34 wrap to form an upper fuel cavity 35, the primary stage nozzle 31 and the main combustion stage nozzle 32 are both communicated with the combustion zone of the nozzle combustor through the nozzle upper cover plate 34, and the fuel in the upper fuel cavity 35 exchanges heat by directly contacting the nozzle upper cover plate 34.

[0037] Among them, the movement mode of the mixture sprayed by the primary stage nozzle 31 is helical movement.

[0038] As Figs. 1-2As shown, the air intake assembly 1 includes an air intake pipe 11, an air cavity 12, an air baffle 13, and a baffle support 14;

[0039] The air intake assembly 1 and the nozzle body 3 are connected by flanges, and part of the nozzle body 3 is embedded in the air intake assembly 1 to form the air cavity 12 together. Compressed air enters the air cavity 12 along the air flow direction, and under the blockage of the air baffle 13, the airflow changes from axial to horizontal direction, and then enters the two-stage nozzle along the standby stage air flow direction and the main combustion stage air flow direction. The fuel intake pipe 2 is uniformly arranged on the side wall of the nozzle body 3 in the circumferential direction and is connected with the upper fuel cavity 35, and the total area of the air intake pipe 2 is marked as A1. In order to reduce the fuel intake flow rate and improve the uniformity of the circumferential fuel intake, the fuel pipe is designed as a flat expansion section at the outlet. After the fuel gas enters the upper fuel cavity 35 along the fuel flow direction, cools and cools the nozzle upper cover plate 34, and then flows into the lower fuel cavity 37 through the fuel flow regulating hole 331 of the fuel flow regulating plate 33, and then flows into the two-stage nozzle through the main combustion stage fuel intake hole 321 and the standby stage fuel intake hole 312, respectively, and mixes with the compressed air and then flows out of the nozzle, and then burns in the combustion zone formed by the flame tube 4.

[0040] One of the bottom surfaces of the air cavity 12 is connected with the nozzle body 3, and the air intake pipe 11 is coaxially installed on the other bottom surface of the nozzle body 3; the air baffle 13 is coaxially installed on the bottom surface of the air cavity 12 where the air intake pipe 11 is located through the baffle support 14. Embodiment

[0041] Based on the first embodiment, as shown in the drawings, Figs. 3-4 As shown, the nozzle body 3 further includes a nozzle lower cover plate 36;

[0042] The nozzle lower cover plate 36 and the fuel flow regulating plate 33 wrap to form a lower fuel cavity 37; the fuel intake pipe 2 is connected with the upper fuel cavity 35;

[0043] The fuel flow regulating plate 33 is provided with fuel flow regulating holes 331 on the surface, which penetrate through the upper fuel cavity 35 and the lower fuel cavity 37.

[0044] The total area of the fuel rectification hole 331 is marked as A2. The nozzle tube bundle inlet and outlet are connected to the nozzle lower end cover and the nozzle upper end cover respectively, and pass through the lower fuel cavity 37 and the upper fuel cavity 35. The nozzle tube bundle can be modularly arrayed according to the actual load demand, and the number of layers is preferably 3-8, and in the embodiment, the number of layers is 4, and the layers are arranged in a staggered manner, so as to reduce the influence of the air inlet of the outer layer tube bundle on the air inlet of the inner layer tube bundle. The nozzle tube bundle is provided with main combustion stage fuel air inlet holes 321 on the side wall of the lower fuel cavity 37, and the main combustion stage fuel air inlet holes 321 are uniformly arranged along the circumference of the single nozzle tube, and the number N is preferably 2-4, and the hole diameter D is preferably 0.5-1.5 mm. From the outside to the inside, the distance between the main combustion stage fuel air inlet holes 321 and the nozzle upper cover plate 34 can be staggered according to the actual demand, or can be linearly changed, and in the embodiment, the distance between the main combustion stage fuel air inlet holes 321 and the nozzle upper cover plate 34 gradually decreases from the outside to the inside, so as to reduce the mutual influence of the air inlets of the different layers, and also to make the air-fuel mixing uniformity (mixing length) of the different layers different, and also to improve the combustion stability. The total area of the main combustion stage fuel air inlet holes 321 is marked as A3.

[0045] The main combustion stage nozzle 32 is provided in a plurality of forms, and the main combustion stage nozzle 32 penetrates the upper fuel cavity 35 and the lower fuel cavity 37.

[0046] One end of the main combustion stage nozzle 32 is connected to the nozzle combustor combustion zone through the nozzle upper cover plate 34, and the other end is connected to the inside of the air inlet assembly 1 through the nozzle lower cover plate 36.

[0047] The main combustion stage nozzle 32 is provided with main combustion stage fuel air inlet holes 321 in the part of the lower fuel cavity 37.

[0048] The standby stage nozzle 31 is provided with a spiral blade 311 inside, and the spiral blade 311 is fixedly installed on the inner side wall of the standby nozzle.

[0049] The structure of the spiral blade 311 is provided in a hollow form.

[0050] The standby stage nozzle 31 is a central cavity region of the nozzle body 3, and the spiral blade 311 is fixed on the side wall of the standby stage nozzle 31 in a threaded rotation form. A circle of standby stage fuel air inlet holes 312 is also arranged on the side wall of the standby stage nozzle 31, and the distance between the standby stage fuel air inlet holes 312 and the nozzle upper cover plate 34 and the number of circles (total number) can be set according to the load and fuel mixing uniformity of the standby stage nozzle 31, and the total area of the standby stage fuel air inlet holes 312 is marked as A4. The above-mentioned air inlet areas are preferably A1>A2>A3+A4, so as to ensure that the fuel air inlet hole position is the fuel air inlet cut-off position, so as to improve the fuel distribution uniformity.

[0051] The on-duty class nozzle 31 is provided with on-duty class fuel air inlet holes 312 in the lower fuel cavity 37.

[0052] The mixture is a mixture of air and fuel.

[0053] The on-duty class nozzle 31 works as follows: compressed air enters the on-duty class nozzle 31 along the air flow direction, the compressed air near the wall rotates under the induction of the spiral blade 311, while the compressed air in the center still mainly keeps the high-speed jet flow form unchanged, the on-duty class fuel is sprayed into the on-duty class nozzle 31 through the on-duty class fuel air inlet holes 312, and is quickly mixed with air under the action of rotating air flow. At the outlet of the on-duty class nozzle 31, the rotating air flow near the wall develops radially under the action of centrifugal force, thereby forming a backflow area (low-speed area) in the combustion area, but the mixed gas in the center area still flows downstream in the form of high-speed jet, and the overall mixed flow structure of the outer ring rotational flow center jet is formed in the combustion area. The outer ring rotational flow can well play a role in stabilizing the flame, and the high-speed center flow makes up for the shortcoming of premixed flame that is easy to backfire, so this embodiment takes into account the advantages of the two technologies, thereby realizing stable and efficient combustion in a wide operating range.

[0054] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled persons in the art, several improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A nozzle combustor for application to a combustion chamber of a gas turbine, characterized by, The air intake assembly (1), the fuel intake pipe (2), the nozzle body (3) and the flame tube (4), the air intake assembly (1) and the nozzle body (3) are coaxially connected, the fuel intake pipe (2) is arranged in the side wall of the nozzle body (3), the flame tube (4) is installed at the outlet of the nozzle body (3), the internal cylindrical area of the flame tube (4) is wrapped to form a nozzle burner combustion zone; The nozzle body (3) includes a standby class nozzle (31), a main combustion class nozzle (32), a fuel rectification plate (33) and a nozzle upper cover plate (34), the main combustion class nozzle (32) is located outside the standby class nozzle (31); The mixture sprayed by the main combustion class nozzle (32) directly passes through the nozzle burner combustion zone; The fuel rectification plate (33) and the nozzle upper cover plate (34) wrap to form an upper fuel chamber (35), the standby class nozzle (31) and the main combustion class nozzle (32) are communicated with the nozzle burner combustion zone through the nozzle upper cover plate (34), and the fuel in the upper fuel chamber (35) exchanges heat by directly contacting the nozzle upper cover plate (34); Wherein, the movement mode of the mixture sprayed by the standby class nozzle (31) is spiral movement; The nozzle body (3) further comprises a nozzle lower cover plate (36); The nozzle lower cover plate (36) and the fuel rectification plate (33) wrap to form a lower fuel chamber (37); The fuel intake pipe (2) is communicated with the upper fuel chamber (35); The surface of the fuel rectification plate (33) is provided with fuel rectification holes (331), which penetrate the upper fuel chamber (35) and the lower fuel chamber (37); The main combustion class nozzle (32) is provided with a plurality of main combustion class nozzles (32), which penetrate the upper fuel chamber (35) and the lower fuel chamber (37); One end of the main combustion class nozzle (32) is communicated with the nozzle burner combustion zone through the nozzle upper cover plate (34), and the other end is communicated with the inside of the air intake assembly (1) through the nozzle lower cover plate (36); Part of the main combustion class nozzle (32) located in the lower fuel chamber (37) is uniformly provided with main combustion class fuel intake holes (321) in the axial direction; The standby class nozzle (31) is provided with a spiral blade (311) inside, and the spiral blade (311) is fixedly installed on the inner side wall of the standby nozzle; The structure of the spiral blade (311) is hollow; The standby class nozzle (31) is provided with standby class fuel intake holes (312) in the axial direction.

2. The nozzle combustor for use in a combustion chamber of a gas turbine according to claim 1, characterized in that, The air intake assembly (1) comprises an air intake pipe (11), an air chamber (12), an air baffle (13) and a baffle support (14); One bottom surface of the air chamber (12) is connected with the nozzle body (3), and the air intake pipe (11) is coaxially installed on the other bottom surface opposite to the nozzle body (3); The air baffle (13) is coaxially installed on the bottom surface of the air chamber (12) where the air intake pipe (11) is located through the baffle support (14).

3. The nozzle combustor for use in a combustion chamber of a gas turbine according to claim 1, characterized in that, The mixture is a mixture of air and fuel.

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