CN113864823B - Turbine engine cyclic heating multistage combustion system - Google Patents

Abstract

The invention discloses a multi-stage combustion system for circulating heating of a turbine engine, which comprises an air inlet channel arranged through a flame tube shell, the flame tube shell includes a preheating insulation layer and a fuel premix layer, and the interior of the preheating insulation layer is a honeycomb connected to each other. A fuel main pipe is wound around the preheating insulation layer. The end of the fuel main pipe penetrates the preheating insulation layer and communicates with the internal honeycomb structure. A fuel channel is arranged between the preheating insulation layer and the fuel premix layer. The fuel channel The outer side is provided with an inlet that communicates with the honeycomb structure, and the inner side is provided with a fuel nozzle that is sprayed to the combustion chamber. The combustion chamber includes a pre-combustion section, a contraction section and an expansion section. The combustion chamber is provided with an air nozzle connected to the intake passage. . The invention can ensure stable and efficient combustion, uniform temperature distribution, lower noise and pollutant emission, and ensure long enough service life and reliability under the premise of ensuring combustion efficiency.

Description

Turbine Engine Circulating Heating Multi-Stage Combustion System

technical field

The invention relates to the technical field of turbine engine combustion, in particular to a cyclic heating multi-stage combustion system of a turbine engine.

Background technique

The fuel turbine engine is referred to as the fuel turbine for short. In the main process of air and fuel, the fuel turbine only has a fuel turbine cycle composed of three components: the compressor (Compressor), the combustion chamber (Combustor) and the fuel turbine (Turbine). cycle. When the fuel turbine is working, the temperature of the flame tube in the combustion chamber is high, and the working environment is very harsh. The material cannot withstand working in a harsh environment far exceeding its normal working temperature for a long time. Therefore, the combustion chamber flame tube must be cooled to prevent the flame tube. Cracks or burns out, reducing engine life.

But paradoxically, the improvement of the fuel turbine cycle efficiency mainly depends on the increase of the exhaust gas temperature of the combustion chamber. When the exhaust gas temperature of the combustion chamber increases, the temperature in the combustion chamber will inevitably increase, and the emission of nitrogen oxides in the combustion chamber will also increase accordingly. At the same time, the working environment of the combustion chamber has also become harsh, such as high pressure, large heat load, high temperature and high speed, and complex flow field. When the combustion chamber temperature rises, cooling the flame tube not only reduces the combustion efficiency, but also causes heat loss.

Therefore, in the prior art, on the basis of ensuring the high combustion efficiency of the combustion chamber, how to improve the performance of the fuel turbine and the low emission pollution is a difficult point to be solved.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies in the background technology, the present invention proposes a cyclic heating multi-stage combustion system for a turbine engine, which solves the technical problem that the combustion efficiency, emissions and structural life of the existing fuel turbine engine cannot be simultaneously improved.

The technical solution of the present invention is achieved as follows: a cyclic heating multi-stage combustion system of a turbine engine includes a flame tube casing, an intake passage extending to the combustion chamber is provided through the flame tube casing, and the flame tube casing includes an external preheating The thermal insulation layer and the internal fuel premixed layer, the interior of the preheating thermal insulation layer is a honeycomb structure that communicates with each other, the front end of the preheating thermal insulation layer is provided with a fuel manifold, and the fuel manifold is wound on the outer wall of the preheating thermal insulation layer. The end penetrates into the preheating insulation layer and communicates with the internal honeycomb structure. A fuel channel is arranged between the preheating insulation layer and the fuel premix layer. The rear end of the fuel channel is closed, and the front end is provided with a front inlet that communicates with the compressor. Gas channel, the outer side of the fuel channel is provided with an inlet that communicates with the honeycomb structure, and the inner side is provided with a fuel nozzle sprayed to the combustion chamber, the combustion chamber includes a pre-combustion section, a contraction section and an expansion section, and the combustion chamber is provided with Air nozzles connected to the air intake passages, the air nozzles and the fuel nozzles are arranged in pairs in the pre-combustion section, the contraction section and the expansion section, and the length of the expansion section is greater than the sum of the lengths of the pre-combustion section and the contraction section.

Further, the front air intake channel includes a honeycomb-shaped communication section at the front, and the honeycomb-shaped communication section is connected with the air nozzle and is provided with a capillary channel between the fuel channel.

Further, the constriction section includes a radial constriction structure protruding inward, the cross section of the radial constriction structure is a semicircle, a number of branch pipes connected to the fuel channel are arranged in the semicircle, and the ends of the two branch pipes are arranged in the semicircle. Connect the same fuel nozzle.

Further, a ring of fuel nozzles is provided along the circumferential direction of the pre-combustion section and the contraction section, and three rings of fuel nozzles are provided along the circumferential direction of the expansion section. The number of fuel nozzles in each ring in the expansion section is Equal to the number of fuel nozzles per ring in the pre-combustion section, the number of fuel nozzles in the constriction section is greater than the number of fuel nozzles in the pre-combustion section.

Further, the front end of the preheating insulation layer is provided with a convex section that protrudes from the outer circumference, the front end of the fuel main pipe penetrates the preheating insulation layer through the convex section and then goes out, and the position where the fuel main pipe penetrates the convex section is set. There are communication holes that communicate with the inner honeycomb structure.

Further, the protruding part of the fuel main pipe after passing through the convex section is a semi-circular pipe, and the semi-circular pipe is uniformly arranged in a spiral shape along the axial direction of the preheating and insulating layer.

Further, the intake passage includes an intake hopper arranged on the outer wall of the preheating and insulating layer, and an intake branch pipe that passes through the preheating insulating layer and the fuel premix layer is connected to the intake hopper, and the air nozzle is provided with at the end of the intake manifold.

Further, adjacent intake branch pipes communicate with each other in the preheating insulation layer and the fuel premixing layer.

Further, a plurality of the fuel passages are provided, and the plurality of fuel passages are arranged in parallel along the length direction of the flame tube casing and communicate with each other.

Further, a plurality of feed branch pipes inserted into the preheating insulation layer are arranged between the front end and the rear end of the fuel main pipe.

The beneficial effects of the present invention include:

(1) The present invention can carry out staged combustion. In the pre-combustion section, the fuel is premixed with the air pressed by the compressor before entering the pre-combustion section. The fuel ejected from the central nozzle of the flame tube is mixed with the air ejected from the air nozzle, and the preliminary combustion is carried out in the pre-combustion section. In this process, the air-fuel ratio is large, and the combustion is a lean mixture, with more gas and less oil, not only complete combustion, The fuel consumption is low, the pollution is small, and the total amount of fuel is small, and the combustion temperature is reduced on the premise of full combustion, which not only reduces the burden on the combustion chamber, but also reduces nitrogen, oxygen and hydrocarbons in the oil-rich combustion area; in the contraction section, The space is reduced, and the fuel converges from the two branch pipes to the same fuel nozzle at a high speed. The high-speed injection of fuel and air will quickly and briefly extinguish the products in the pre-combustion section, but the reaction path and time are very short, that is, high nitrogen oxidation. In the expansion section, the injected fuel and air are mixed with the oil-rich fuel in the contraction section for supplementary combustion, so that the combustion is stable and efficient, the temperature distribution is uniform, and noise and pollution are generated. lower emissions;

(2) The air entering the front intake passage from the compressor can be fully pre-mixed with the fuel in the pre-combustion section, and can also be partially pre-mixed with the fuel in the contraction section and expansion section, and can also be preheated. The internal cooling of the flame tube heated by the internal high-temperature airflow hardly affects the high-temperature environment inside the combustion chamber, and at the same time, it can also play a noise reduction function to reduce the noise generated by the compressor supplying air to the combustion chamber.

(3) An extended fuel main pipe is added on the flame tube shell, which can cool the flame tube shell and preheat the fuel at the same time, so as to improve the combustion efficiency. Further, the preheating insulation layer is set as a honeycomb structure that is connected to each other inside, and the fuel main pipe enters the preheating insulation layer through the feed branch pipe, which not only realizes the external preheating of the fuel through the casing of the flame tube, but also the internal structure of the fuel. The internal preheating is realized, the fuel is fully evaporated to reach a supercritical state, the viscosity is reduced, and the diffusivity is enhanced, and then it can be mixed with the air more fully and uniformly, which fully improves the combustion efficiency and reduces the pollutant emission.

(4) Fuel and air control the temperature of the entire flame tube from the inside to the outside. The fuel channel is set between the preheating insulation layer and the fuel premix layer, which not only ensures the adequacy of preheating and cooling, but also avoids excessive heat Dissipation - The honeycomb structure inside the preheating insulation layer not only allows the fuel to be fully exchanged and preheated, but also forms a metal-fuel composite insulation layer, and the internal fuel premixed layer isolates the combustion chamber from the preheating insulation layer. It also ensures structural reliability while retaining heat.

Description of drawings

In order to illustrate the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, which are common in the art. As far as technical personnel are concerned, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the sectional structure schematic diagram of the present invention;

FIG. 3 is a left-view structural schematic diagram of the present invention;

In the picture:

1- preheat insulation layer, 2- fuel premix layer,

3- fuel main pipe, 31- communication hole, 32- semicircular pipe,

4-fuel channel, 41-inlet, 42-branch pipeline;

5-front air intake channel, 51-honeycomb connecting section, 52-capillary channel;

7-combustion chamber, 8-fuel nozzle;

9-intake bucket, 91-air nozzle;

10-pre-combustion section, 11-contraction section, 12-expansion section, 13-bulge section;

101 - Radial contraction structure.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

A cyclic heating multi-stage combustion system for a turbine engine, as shown in Figures 1 to 3, includes a flame tube casing, and the flame tube casing includes an external preheating insulation layer 1 and an internal fuel premix layer 2. The preheating and thermal insulation layer Layer 1 and the inner fuel premixed layer 2 can be fabricated by 3D printing technology. Specifically, the interior of the preheating insulation layer 1 is a honeycomb structure that is connected to each other. The internal structure is shaped like a honeycomb but connected to each other. When the gas enters, it can flow back and forth, and will flow toward the outlet under a certain pressure. .

The front end of the preheating insulation layer 1 is provided with a fuel main pipe 3, which is wound on the outer wall of the preheating insulation layer 1. When the fuel flows through the fuel main pipe 3, it will be heated by the outer wall of the preheating insulation layer 1, thereby reducing the temperature. The viscosity of the fuel and the fluidity of the fuel are enhanced. The end of the fuel main pipe 3 penetrates into the preheating and insulating layer 1 and communicates with the internal honeycomb structure. The fuel heated by the outer wall of the preheating and insulating layer 1 will enter the honeycomb-like interior of the preheating and insulating layer 1, and the fuel is connected to each other. The flow in the honeycomb structure further heats up, thereby further reducing the viscosity of the fuel and enhancing the fluidity of the fuel.

A fuel channel 4 is provided between the preheating insulation layer 1 and the fuel premix layer 2 . The outer side of the fuel channel 4 is provided with an inlet 41 that communicates with the honeycomb structure, and the inner side is provided with a fuel nozzle 8 that sprays into the combustion chamber 7 . After the fuel passes through the interconnected honeycomb structure inside the preheating insulation layer 1, it will converge into the fuel passage 4. Since the fuel passage 4 is closer to the combustion chamber 7, the fuel in the fuel passage 4 will be further heated and heated up to reach In the supercritical state, the viscosity of the fuel becomes lower, the diffusivity of the fuel increases, and it can be easily mixed with air.

The rear end of the fuel passage 4 is closed, and the front end is provided with a front air intake passage 5 that communicates with the compressor. Premixing of fuel. An intake passage extending to the combustion chamber is provided through the casing of the flame tube, and an air nozzle 91 connected to the intake passage is provided in the combustion chamber 7 . The intake passage includes an intake hopper 9 arranged on the outer wall of the preheating and insulating layer 1, and is connected with the intake hopper 9 and is provided with an intake branch pipe passing through the preheating and insulating layer 1 and the fuel premix layer 2. The nozzle 91 is provided at the end of the intake branch pipe. The front air intake passage 5 includes a honeycomb-shaped communication section 51 at the front. The honeycomb-shaped communication section 51 is connected to the air nozzle 91 and is provided with a capillary channel 52 between it and the fuel passage 4 . Part of the air delivered by the compressor to the front intake passage 5 is directly premixed with the fuel, and the other part is injected into the combustion chamber 7 through the air nozzle 91 .

The combustion chamber 7 includes a pre-combustion section 10 , a constricted section 11 and an expanded section 12 , and the air nozzles 91 and the fuel nozzles 8 are paired in the pre-combustion section 10 , the constricted section 11 and the expanded section 12 . The diameter of the pre-combustion section 10 and the diameter of the expansion section 12 are both larger than the diameter of the contraction section 11, and the length of the expansion section 12 is greater than the sum of the lengths of the pre-combustion section 10 and the contraction section 11, and enters the combustion through the air nozzle 91 and the fuel nozzle 8. The mixed fuel in the chamber 7 is fully mixed and fully burned in the pre-combustion section 10, briefly extinguished in the contraction section 11, and mixed with the oil-rich fuel in the contraction section in the expansion section 12 for supplementary combustion. The specific process is: in the pre-combustion section, before the fuel enters the pre-combustion section, it is first premixed with the air pressed by the compressor, and the pre-mixed fuel is sprayed from a small amount of fuel nozzles in the pre-combustion section, and the fuel is sprayed from the center nozzle of the flame tube. The outgoing fuel is mixed with the air ejected from the air nozzle, and preliminary combustion is carried out in the pre-combustion section. In this process, the air-fuel ratio is large, and the combustion is a lean mixture, with more gas and less oil, not only complete combustion, low fuel consumption, and low pollution , and the total amount of fuel is small, the combustion temperature is reduced under the premise of full combustion, which not only reduces the burden on the combustion chamber, but also reduces nitrogen oxides and hydrocarbons in the oil-rich combustion area; in the shrinking section, the space is reduced, and the fuel From the high-speed convergence, the high-speed injected fuel and air will quickly and briefly extinguish the products of the pre-combustion section, but the reaction path and time are very short, that is, the production process of high nitrogen oxides is extremely short, and the generated nitrogen oxides are less; In the expansion section, the injected fuel and air are mixed with the oil-rich fuel in the contraction section for supplementary combustion, resulting in stable and efficient combustion, uniform temperature distribution, and lower noise and pollutant emissions.

Specifically, the constriction section 11 includes a radial constriction structure 101 protruding inward, and the radial constriction structure 101 has a semicircular cross section, which ensures that the process of combustion, quenching and re-ignition is relatively soft, and also ensures the structural strength. reliability. A number of branch pipes 42 connected to the fuel passage 4 are arranged in the semicircle, and the ends of the two branch pipes 42 are connected to the same fuel nozzle 8, so that the fuel nozzle in the constricted section 11 injects a large amount of fuel at a high speed, which ensures that both The fuel in the pre-combustion section 10 burns out quickly, and can also provide support for the supplementary combustion of the expansion section 12 at the rear, so that the combustion is stable and efficient, and the temperature distribution is uniform. A ring of fuel nozzles 8 are arranged along the circumferential direction of the pre-combustion section 10 and the constricted section 11, and three rings of fuel nozzles 8 are arranged along the circumferential direction of the expansion section 12. The fuel nozzles 8 of each ring in the expansion section 12 The number of nozzles 8 is equal to the number of fuel nozzles 8 in each ring in the pre-combustion section 10 , and the number of fuel nozzles 8 in the constricted section 11 is greater than the number of fuel nozzles 8 in the pre-combustion section 10 .

Further, the front end of the preheating and insulating layer 1 is provided with a convex section 13 that protrudes to the outer circumference. The position of the raised section 13 is provided with a communication hole 31 which communicates with the internal honeycomb structure, so that the fuel can enter the inside and outside of the preheating insulation layer at the same time, so as to realize the stepped preheating of the fuel and the stepped cooling of the flame tube.

Further, the protruding part of the fuel main pipe 3 after passing through the protruding section 13 is a semicircular pipe 32 , and the semicircular pipe 32 is uniformly arranged in a spiral shape along the axial direction of the preheating and insulating layer 1 . The preheating and insulating layer is set as an interconnected honeycomb structure. The fuel main pipe enters the preheating and insulating layer through the feed branch pipe. Preheating makes the fuel fully evaporate to reach the supercritical state, the viscosity becomes lower and the diffusivity is enhanced, and then it can be mixed with the air more fully and evenly, which fully improves the combustion efficiency and reduces the pollutant emission.

Further, the adjacent intake branch pipes are communicated with each other in the preheating insulation layer 1 and the fuel premix layer 2, the fuel passages 4 are provided with several, and the several fuel passages 4 are arranged in parallel along the length direction of the flame tube shell and are arranged in parallel with each other. connected to each other. A number of feed branch pipes inserted into the preheating and insulating layer 1 are arranged between the front end and the rear end of the fuel main pipe 3 . The preheating effect of air and fuel is better and uniform, and the cooling of the flame tube is more uniform and sufficient. Fuel and air control the temperature of the entire flame tube from the inside to the outside. The fuel channel is set between the preheating insulation layer and the fuel premix layer, which not only ensures the adequacy of preheating and cooling, but also avoids excessive heat loss—— The honeycomb structure inside the preheating insulation layer not only allows the fuel to be fully exchanged and preheated, but also forms a metal-fuel composite insulation layer. At the same time, the structural reliability is also guaranteed.

The non-exhaustive parts of the present invention are conventional technical means known to those skilled in the art.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. Turbine engine circulation heating multistage combustion system, including the flame tube shell, pass the flame tube shell and be provided with the inlet channel who extends to the combustion chamber, its characterized in that: the flame tube shell comprises an external preheating heat-insulating layer (1) and an internal fuel premixing layer (2), the internal preheating heat-insulating layer (1) is of a honeycomb structure communicated with each other, a fuel header pipe (3) is arranged at the front end of the preheating heat-insulating layer (1), the fuel header pipe (3) is wound on the outer wall of the preheating heat-insulating layer (1), the tail end of the fuel header pipe (3) penetrates into the preheating heat-insulating layer (1) and is communicated with the internal honeycomb structure, a fuel channel (4) is arranged between the preheating heat-insulating layer (1) and the fuel premixing layer (2), the rear end of the fuel channel (4) is sealed, the front end of the fuel channel is provided with a front air inlet channel (5) communicated with a gas compressor, the outer side of the fuel channel (4) is provided with an inlet (41) communicated with the honeycomb structure, the inner side of the fuel nozzle (8) for spraying to a combustion chamber (7) is arranged, and the combustion chamber (7) comprises a pre-burning section (10), The combustor comprises a contraction section (11) and an expansion section (12), an air nozzle (91) connected with an air inlet channel is arranged in the combustion chamber (7), the air nozzle (91) and a fuel nozzle (8) are arranged in the precombustion section (10), the contraction section (11) and the expansion section (12) in pairs, and the length of the expansion section (12) is greater than the sum of the lengths of the precombustion section (10) and the contraction section (11).

2. The turbine engine hydronic multistage combustion system of claim 1, wherein: the front air inlet channel (5) comprises a front honeycomb-shaped communicating section (51), the honeycomb-shaped communicating section (51) is connected with the air nozzle (91) and a capillary channel (52) is arranged between the honeycomb-shaped communicating section and the fuel channel (4).

3. The turbine engine hydronic multistage combustion system according to claim 1 or 2, characterized in that: the contraction section (11) comprises a radial contraction structure (101) protruding inwards, the cross section of the radial contraction structure (101) is semicircular, a plurality of branch pipelines (42) connected with the fuel channel (4) are arranged in the semicircle, and the tail ends of the two branch pipelines (42) are connected with the same fuel nozzle (8).

4. The turbine engine hydronic multistage combustion system according to claim 3, wherein: the fuel injection device is characterized in that a ring of fuel nozzles (8) are arranged in the circumferential direction of the pre-combustion section (10) and the contraction section (11), three rings of fuel nozzles (8) are arranged in the circumferential direction of the expansion section (12), the number of the fuel nozzles (8) in each ring in the expansion section (12) is equal to that of the fuel nozzles (8) in each ring in the pre-combustion section (10), and the number of the fuel nozzles (8) in the contraction section (11) is larger than that of the fuel nozzles (8) in the pre-combustion section (10).

5. The turbine engine cycle heating multistage combustion system of any of claims 1, 2, 4, wherein: the front end of preheating heat preservation (1) is provided with protruding section (13) to the periphery arch, wear out after the front end of fuel house steward (3) penetrates preheating heat preservation (1) through protruding section (13), and the position that fuel house steward (3) penetrated protruding section (13) is provided with intercommunicating pore (31) with inside honeycomb structure intercommunication.

6. The turbine engine hydronic multistage combustion system according to claim 5, wherein: the part of the fuel main pipe (3) extending out after penetrating through the convex section (13) is a semicircular pipe (32), and the semicircular pipe (32) is spirally and uniformly arranged along the axial direction of the preheating heat-insulating layer (1).

7. The turbine engine hydronic multistage combustion system according to claim 6, wherein: the air inlet passage comprises an air inlet hopper (9) arranged on the outer wall of the preheating heat-insulating layer (1), an air inlet branch pipe penetrating through the preheating heat-insulating layer (1) and the fuel premixing layer (2) is connected with the air inlet hopper (9), and the air nozzle (91) is arranged at the tail end of the air inlet branch pipe.

8. The turbine engine hydronic multistage combustion system according to claim 7, wherein: the adjacent air inlet branch pipes are communicated with each other in the preheating and insulating layer (1) and the fuel premixing layer (2).

9. The turbine engine cycle heating multistage combustion system of any of claims 1, 2, 4, 6, 7, wherein: the number of the fuel channels (4) is multiple, and the fuel channels (4) are arranged in parallel along the length direction of the flame tube shell and are communicated with each other.

10. The turbine engine hydronic multistage combustion system according to claim 9, wherein: a plurality of feeding branch pipes inserted into the preheating heat-insulating layer (1) are arranged between the front end and the rear end of the fuel main pipe (3), the outer ends of the feeding branch pipes are communicated with the fuel main pipe (3), and the inner ends of the feeding branch pipes are communicated with the honeycomb structure.

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