CN116006964A

CN116006964A - Oil supply device of integrated concave cavity trapped vortex combustion chamber

Info

Publication number: CN116006964A
Application number: CN202310016110.6A
Authority: CN
Inventors: 肖建昆; 周天成; 李明玉; 李俊锋
Original assignee: Jiangsu University of Science and Technology
Current assignee: Jiangsu University of Science and Technology
Priority date: 2023-01-06
Filing date: 2023-01-06
Publication date: 2023-04-25

Abstract

The invention discloses an oil supply device of an integrated concave cavity standing vortex combustion chamber, which comprises a shell, a cap cover, a flow guide head and a concave cavity, wherein the concave cavity is arranged in the shell, the cap cover and the flow guide head are arranged on the front wall of the concave cavity, a main air inlet channel of the concave cavity is formed between the cap cover and the flow guide head, a cooling air inlet seam is formed in the front end of the cap cover and used for guiding airflow to cool the front wall of the concave cavity, an air inlet nozzle, an evaporation mixer and a distributor are arranged in the cap cover, the distributor and the evaporation mixer are tightly attached to the front wall of the concave cavity, the air inlet nozzle is positioned in the cooling air inlet seam, the air inlet nozzle extends inwards from the front end of the cap cover and is communicated with the head end of the evaporation mixer, the tail end of the evaporation mixer is communicated with the distributor for supplying oil, and the distributor is used for supplying oil to the concave cavity, and an oil supply pipe for injecting oil into the air inlet nozzle is arranged in front of the air inlet nozzle. The invention can improve the oil-gas mixing degree, promote combustion efficiency, simultaneously evaporate fuel oil to dissipate heat to the front wall of the concave cavity, prolong the service life of materials and reduce weight due to the integrated design of the structure.

Description

Oil supply device of integrated concave cavity trapped vortex combustion chamber

Technical Field

The invention relates to a combustion chamber oil supply device, in particular to an oil supply device of an integrated concave cavity trapped vortex combustion chamber.

Background

The trapped vortex combustor is a novel combustion device which makes the trapped vortex flow structure by reasonably organizing the air fed into the cavity, and the vortex is protected by the cavity so that the flame can be stabilized in a wider range. In addition, the high-altitude ignition device has the characteristics of simple structure, light weight, short length, stable combustion, excellent high-altitude ignition performance, high combustion efficiency maintenance in a wider working range, low pollutant discharge and the like, and a great amount of manpower and material resource development research is started in all countries of the world, and rich results are obtained. However, there are still many disadvantages to the research on the technology of supplying oil to the cavity.

Most existing trapped vortex combustors use liquid fuel. The combustion of liquid fuel generally comprises four stages of fuel atomization, fog drop evaporation, oil mist and air mixing and oil gas ignition combustion. In general, the combustion of liquid fuel belongs to heterogeneous diffusion combustion, the reaction of three stages except evaporation is very rapid, and the evaporation process is the slowest link, namely, the combustion speed of liquid fuel mainly depends on the evaporation speed. In order to shorten the evaporation time, in addition to adopting a working medium with good atomization performance and favorable evaporation conditions, it is critical to increase the evaporation surface of the liquid fuel, i.e. to atomize the liquid fuel into very fine mist droplets by using a nozzle. Atomization of liquid fuel is therefore a very important contributor to combustion chamber performance. The fuel atomization of the combustion chamber mainly utilizes various types of nozzles as important components in the combustion chamber, and the performance of the nozzles has great influence on the combustion process. Therefore, the oil supply device suitable for the trapped vortex combustion chamber has the following two characteristics: firstly, the oil supply device can achieve good atomization effect; secondly, the oil supply device can be well matched with the structure of the standing vortex combustion chamber.

Early trapped vortex combustors primarily employed direct injection nozzles as the fueling solution for the cavity. However, the direct injection nozzle has poor atomization performance, is not favorable for ignition, and is difficult to meet the requirement of the standing vortex combustion chamber for realizing efficient combustion under various working conditions, especially under low working conditions. Centrifugal nozzles, while widely used as a fueling solution for cavities in recent trapped vortex combustor studies, have difficulty matching the flow field configuration within the cavity because the fuel spray mist pattern of the centrifugal nozzle is a conical mist. When the concave cavity adopts the centrifugal nozzle to supply oil, a part of fuel oil sprayed by the centrifugal nozzle can be directly sprayed to the bottom wall of the concave cavity, so that the loss of carbon deposition and combustion efficiency can be caused, and a great challenge is brought to the cooling of the bottom wall of the concave cavity. The evaporating pipe nozzle sprays fuel into the evaporating pipe in a direct injection mode with lower pressure, the fuel is heated by the fuel flow in the combustion chamber, the fuel is primarily evaporated and mixed, and then the fuel is converged into the concave cavity from the exhaust hole for combustion. The oil-gas mixture formed by the evaporating pipe type nozzle is uniform, easy to ignite, high in combustion efficiency, free from smoke emission and uniform and stable in outlet temperature field. In addition, the evaporating pipe has the characteristics of simple structure, light weight, matching with the airflow of the concave combustion area and the like, and is suitable for being used as a concave cavity oil supply device of the trapped vortex combustion chamber. However, the oil supply device for the evaporating pipe has the same defects that the evaporating pipe used in the standing vortex combustion chamber is used for injecting oil into the evaporating pipe in a direct injection mode through a nozzle at lower pressure, the gas flow on the periphery of the evaporating pipe and the burnt gas flow in the combustion chamber heat the fuel gas, so that the fuel oil is primarily evaporated and mixed, and the gaseous rich oil mixed gas is formed to enter the combustion chamber to be mixed and combusted with the gas flow entering the main combustion hole. However, the area where the conventional evaporation tube is disposed is not closely attached to the cavity and requires additional space for the combustion chamber, which causes two problems, namely, the lack of fully utilizing the heat released by the combustion in the cavity to accelerate the evaporation, resulting in low efficiency, and the increase in the weight and volume of the combustion chamber.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an oil supply device of an integrated concave cavity standing vortex combustion chamber, which solves the problems that the traditional evaporation tube oil supply device does not fully utilize the combustion heat of a concave cavity, needs to occupy the space of the combustion chamber additionally and increases the weight of the combustion chamber.

The technical scheme of the invention is as follows: the utility model provides an integrated form cavity resident vortex combustion chamber's oil supply unit, includes air inlet nozzle, evaporation mixer and distributor, integrated form cavity resident vortex combustion chamber includes cap cover and cavity, the cap cover sets up the front wall of cavity, the front end of cap cover is equipped with the cooling air inlet seam, the cooling air inlet seam is used for guiding the air current cooling the front wall of cavity, air inlet nozzle, evaporation mixer and distributor set up in the cap cover, the distributor with evaporation mixer hug closely in the front wall of cavity, the air inlet nozzle is located the cooling air inlet seam, the air inlet nozzle by the front end of cap cover inwards extend with evaporation mixer's head end intercommunication, evaporation mixer's tail end with the distributor intercommunication, the distributor is used for to the fuel feeding in the cavity, the place ahead of air inlet nozzle is equipped with the fuel feeding pipe of the fuel injection in the air inlet nozzle.

Further, in order to improve the uniformity of fuel entering the concave cavity and the uniformity of fuel and air mixing, the air inlet nozzles are uniformly arranged at intervals along the cooling air inlet seam.

Further, the inlet area of the air inlet nozzle occupies 1/5-1/3 of the area of the air inlet seam.

Further, the distributor forms a plurality of oil spraying holes which are arranged at intervals along the ring shape of the distributor on the front wall of the concave cavity, and the aperture of the oil spraying holes is 2-10 mm.

Further, in order to ensure that the cooling air inlet seam is better in cooling effect and the fuel oil can be fully vaporized and atomized, the cap cover comprises a first wall plate and a second wall plate, the first wall plate is closer to the center of the front wall of the concave cavity than the second wall plate, the cooling air inlet seam is formed between the front end of the first wall plate and the front end of the second wall plate, and the air inlet nozzle is tightly attached to the first wall plate and extends.

Further, the distributor and the concave cavity are arranged in a coaxial annular shape, and the evaporation mixer is arranged along the radial direction of the annular shape.

According to the invention, the fuel oil supply device is arranged in the deflector cap of the concave cavity combustion chamber, the fuel oil enters the air inlet nozzle along the main air flow, and when the fuel oil flows through the evaporation mixer, the fuel oil evaporates in the evaporation mixer and is mixed with main air in the cavity as the fuel gas flow in the concave cavity reaches a very high temperature, and finally the fuel oil is uniformly sprayed into the concave cavity from the distributor to form a stable vortex flow structure together with the precursor air supply and the post air supply of the concave cavity. Compared with the prior art, the invention has the advantages that:

1. the fuel supply device is arranged in the flow guide cap, heat generated during the working of the combustion chamber is directly transmitted to the inner wall of the evaporation mixer, fuel entering from the air inlet nozzle can absorb heat on the inner wall of the evaporation mixer and quickly evaporate, and the fuel is fully mixed with atomization-assisting air entering the evaporation mixer, so that the mixing degree of the fuel and the air is improved, and the combustion process is enhanced.

2. The combustion of the flame in the concave cavity can lead to overheating of the combustion chamber, the service life of materials is shortened, and the fuel oil and atomization aid air entering from the air inlet nozzle can exactly absorb heat released by the combustion of part of the concave cavity, so that the wall surface of the concave cavity is cooled, and the service life is prolonged.

3. The oil supply device and the diversion cap cover are integrally designed, the space inside the combustion chamber is fully utilized, the structural weight is reduced, in addition, the air inlet nozzle, the evaporation mixer and the distributor are simple in structure, oil supply is uniform, the evaporation effect is good, and the oil supply device has great advantages as a cavity oil supply mode of the standing vortex combustion chamber, so that fuel oil and air are better matched in the cavity.

Drawings

Fig. 1 is a schematic perspective view of an integrated cavity trapped vortex combustor according to an embodiment.

FIG. 2 is a schematic perspective view (partially cut away) of an integrated cavity trapped vortex combustor according to an embodiment

Fig. 3 is a partially enlarged schematic view at a of fig. 2.

Fig. 4 is a schematic view of the backside view angle structure of fig. 3.

Fig. 5 is a schematic diagram of operation of an integrated cavity trapped vortex combustor of an embodiment.

Fig. 6 is a partially enlarged schematic view at B of fig. 5.

Detailed Description

The invention is further illustrated, but is not limited, by the following examples.

In order to more clearly illustrate the oil supply device of the integrated cavity trapped vortex combustion chamber of the present invention, the structure of the integrated cavity trapped vortex combustion chamber is described first, and as shown in fig. 1 to 4, an annular combustion chamber is taken as an example, and the integrated cavity trapped vortex combustion chamber comprises a housing 1, a cap 2, a flow guide head 3 and a cavity 4. That is, as shown in fig. 1, in which the casing 1 includes an outer casing 101 and an inner casing 102, the outer casing 101 constitutes an outer ring, the inner casing 102 constitutes an inner ring, the space between the front ends of the outer casing 101 and the inner casing 102 is small to form an intake passage a, and the space between the outer casing 101 and the inner casing 102 constitutes a trapped vortex combustion chamber and is used for providing the cap 2, the flow guide head 3, and the cavity 4.

Fig. 2 shows a section of the circumference of a combustion chamber which is annular. The structure of the cavity 4 is a prior art structure, the front wall 401 of the cavity is opposite to the air inlet channel a formed by the outer shell 101 and the inner shell 102, and an air inlet slot of the front wall 401 is formed at the position, close to the edge, of the front wall 401, so that part of air flow passing through the cavity 4 and the shell enters the cavity 4. The cap 2 and the deflector 3 are arranged at the front wall 401 of the cavity 4. Wherein the flow guide head 3 is aligned with the air inlet channel a on the shell, so that air flows to the lateral direction of the flow guide head 3.

The cap 2 comprises a first wall plate 201 and a second wall plate 202, the first wall plate 201 is one side close to the flow guiding head 3, the second wall plate 202 is one side far away from the flow guiding head 3 (close to the outer shell 101 and the inner shell 102), a cooling air inlet gap b is formed between the front end of the first wall plate 201 and the front end of the second wall plate 202, a main air inlet c of the concave cavity 4 is formed between the first wall plate 201 and the flow guiding head 3, and a through hole is correspondingly formed in the front wall 401 of the concave cavity 4 and is communicated with the main air inlet c. A portion of the air flow directed to both sides via the deflector head 3 enters the cavity 4 from the main inlet c. The second wall 202 of the cap 2 is an arcuate plate, the trailing end of the second wall 202 extending to the inlet seam of the front wall 401 of the cavity 4. Part of the air flow through the cap 2 enters the cap 2 from the cooling air inlet slot b for cooling the front wall 401 of the cavity 4 and the other part is directed towards the front wall air inlet slot d of the cavity 4.

The oil supply device of the integrated concave cavity trapped vortex combustion chamber is mainly arranged in the cap cover 2 and consists of an air inlet nozzle 5, an evaporation mixer 6, a distributor 7 and an oil supply pipe 8. The distributor 7 and the evaporation mixer 6 are arranged close to the front wall 401 of the cavity 4, wherein the distributor 7 is arranged close to the second wall plate 202 of the cap 2 and close to the air inlet seam d of the front wall of the cavity 4, the distributor 7 and the annular combustion chamber are arranged in a concentric annular shape, and the air inlet nozzle 5 and the evaporation mixer 6 are rectangular channels. The distributor 7 forms a plurality of oil spray holes 701 in the front wall 401 of the cavity 4, which are annularly spaced along the distributor 7, and the diameter of the oil spray holes 701 is 2-10 mm as shown in fig. 4. The distributor 7 feeds the blended fuel and air into the cavity 4 through these injection holes 701. The front end of the air inlet nozzle 5 is positioned at the cooling air inlet seam b, the air inlet nozzle 5 is clung to the first wallboard 201 and extends towards the concave cavity 4, and an oil supply pipe 8 for injecting oil into the air inlet nozzle 5 is arranged in front of the air inlet nozzle 5. On the annular cooling air inlet seam b, a plurality of air inlet nozzles 5 are uniformly arranged at intervals, and the inlet area of the air inlet nozzles 5 occupies 1/5-1/3 of the area of the air inlet seam, so that on one hand, enough passages are provided for fuel oil, and on the other hand, the direct cooling effect of air flow on the front wall 401 of the concave cavity 4 can be ensured. The head end and the tail end of the evaporation mixer 6 are respectively connected with the air inlet nozzle 5 and the distributor 7, and the evaporation mixer 6 is arranged along the annular radial direction of the distributor 7. As shown in fig. 5 and 6, the fuel and air entering from the air inlet nozzle 5 flow through the evaporation mixer 6 and then enter the distributor 7, and heat is directly conducted through the front wall 401 in the evaporation mixer 6, so that the fuel is heated by the high-temperature burnt gas in the cavity 4, the fuel is accelerated to evaporate and is mixed with the air entering together into the distributor 7, and further mixed into an oil-gas mixture, and then uniformly enters the cavity 4 for combustion.

In some integrated cavity trapped vortex combustors, the cap 2 is symmetrically arranged on both sides of the flow guide head 3 as seen in a radial section of the combustor, i.e. the cap 2 is arranged on the side of the flow guide head 3 towards the outer casing 101 and towards the inner casing 102 respectively, and the corresponding cavities 4 are also symmetrically arranged. It can be understood that the caps 2 on both sides of the flow guide head 3 of the integrated concave cavity trapped vortex combustion chamber are provided with oil supply devices, and the structures are same and symmetrically arranged relative to the flow guide head 3.

In summary, the invention solves the problems that the traditional evaporating pipe cannot fully utilize the combustion heat of the concave cavity 4, needs to occupy the space of the combustion chamber additionally, and increases the weight of the combustion chamber under the condition of not changing the original general structure of the standing vortex combustion chamber. On the one hand, after entering the air intake nozzle 5 with the main flow of air, the heat need not be provided additionally to meet the evaporation requirement of the fuel in the evaporation mixer 6 due to the high temperature of the front wall 401 of the combustion chamber cavity 4. The high temperature enables the fuel oil to be fully evaporated in the evaporation mixer 6 and be mixed with main stream air, so that the mixing degree between oil and gas is improved, the combustion process is enhanced, and the combustion efficiency is improved. On the other hand, the fuel and the main stream air entering the evaporative mixer 6 can reduce the wall temperature during the contact with the front wall 401 of the cavity 4, so that the working temperature of the combustion chamber is not excessively high continuously, and the service life of the material is prolonged. In addition, the oil supply device of the whole concave cavity trapped vortex combustion chamber and the combustion chamber cap cover 2 are integrally designed, so that the head space of the combustion chamber is fully utilized, and the structural weight is reduced.

Claims

1. The utility model provides an integrated form cavity resident vortex combustion chamber's oil supply unit, its characterized in that includes air inlet nozzle, evaporation mixer and distributor, integrated form cavity resident vortex combustion chamber includes cap cover and cavity, the cap cover sets up the front wall of cavity, the front end of cap cover is equipped with the cooling air inlet seam, the cooling air inlet seam is used for guiding the air current cooling the front wall of cavity, air inlet nozzle, evaporation mixer and distributor set up in the cap cover, the distributor with evaporation mixer hug closely in the front wall of cavity, the air inlet nozzle is located the cooling air inlet seam, the air inlet nozzle by the front end of cap cover inwards extend with evaporation mixer's head end intercommunication, evaporation mixer's tail end with the distributor intercommunication, the distributor is used for to the fuel feeding in the cavity, the place ahead of air inlet nozzle is equipped with the fuel feeding pipe of spout in the air inlet nozzle.

2. The oil supply device for the integrated recessed cavity trapped vortex combustor of claim 1, wherein said air inlet nozzles are uniformly spaced along said cooling air inlet gap.

3. The oil supply device for the integrated recessed cavity trapped vortex combustion chamber of claim 2, wherein the inlet area of the air inlet nozzle occupies 1/5 to 1/3 of the area of the air inlet gap.

4. The oil supply device for the integrated recessed cavity trapped vortex combustion chamber according to claim 1, wherein the distributor forms a plurality of oil spray holes which are annularly arranged at intervals along the distributor on the front wall of the recessed cavity, and the aperture of the oil spray holes is 2-10 mm.

5. The oil supply device for an integrated cavity trapped vortex combustor of claim 1, wherein the cap includes a first wall plate and a second wall plate, the first wall plate being closer to a center of a front wall of the cavity than the second wall plate, the front end of the first wall plate and the front end of the second wall plate forming the cooling air intake slot therebetween, the air intake nozzle extending against the first wall plate.

6. The oil supply device for an integrated cavity trapped vortex combustor of claim 5, wherein said distributor is disposed in a concentric annular configuration with said cavity, said evaporative mixer being disposed radially of said annular configuration.