阅读说明：本技术 一种燃气自循环预热的蒸发式凹腔火焰稳定器 (Evaporative cavity flame stabilizer with self-circulation preheating of fuel gas ) 是由 范育新 缪俊杰 赵世龙 吴伟秋 刘天池 于 2019-10-24 设计创作，主要内容包括：本发明公开了一种燃气自循环预热的蒸发式凹腔火焰稳定器,包括凹腔火焰稳定器,凹腔火焰稳定器的后壁后端水平延伸有防护板,所述防护板上方设置有蒸发式供油机构,所述蒸发式供油机构具有一个与喷油装置连通的蒸发腔,所述蒸发式供油机构与所述后壁之间形成用于外涵道气流引入的第一流道,所述蒸发式供油机构与防护板之间形成与所述第一流道连通的第二流道。本发明利用燃气回流对液态煤油预热的方式加速煤油的雾化、蒸发及与空气的混合,改善凹腔火焰稳定器的点火性能和火焰稳定能力,解决现有凹腔火焰稳定器在低温和高速气流下的贫油点火和稳定燃烧性能不足的问题。(The invention discloses an evaporative cavity flame stabilizer with self-circulation preheating of fuel gas, which comprises a cavity flame stabilizer, wherein a protection plate horizontally extends from the rear end of the rear wall of the cavity flame stabilizer, an evaporative oil supply mechanism is arranged above the protection plate, the evaporative oil supply mechanism is provided with an evaporation cavity communicated with an oil injection device, a first flow passage for introducing an outer duct airflow is formed between the evaporative oil supply mechanism and the rear wall, and a second flow passage communicated with the first flow passage is formed between the evaporative oil supply mechanism and the protection plate. The invention accelerates the atomization and evaporation of the kerosene and the mixing of the kerosene and air by utilizing the mode of preheating the liquid kerosene by gas reflux, improves the ignition performance and the flame stabilizing capability of the concave cavity flame stabilizer and solves the problems of insufficient lean oil ignition and stable combustion performance of the traditional concave cavity flame stabilizer under low-temperature and high-speed airflow.)

1. An evaporative cavity flame stabilizer with self-circulation preheating of fuel gas comprises a cavity flame stabilizer (1), the re-entrant flame holder having a re-entrant cavity (101) and front (102), main (103) and rear (104) walls enclosing the cavity (101), characterized in that the rear end of the rear wall (104) horizontally extends with a protection plate (2), an evaporative oil supply mechanism (3) is arranged above the protection plate (2), the evaporative oil supply mechanism (3) is provided with an evaporation cavity (301) communicated with an oil injection device, a first flow channel (4) for introducing an outer duct airflow is formed between the evaporative oil supply mechanism (3) and the rear wall (103), a second flow channel (5) communicated with the first flow channel (4) is formed between the evaporative oil supply mechanism (3) and the protection plate (2), and an airflow outlet is formed in the first flow channel and/or the second flow channel; and a plurality of third flow channels (6) used for sending the gas in the cavity (101) into the evaporation cavity (301) and a plurality of fourth flow channels (7) used for sending out the premixed gas and oil in the evaporation cavity (301) are arranged between the cavity (101) and the evaporation cavity (301).

2. The evaporative cavity flame holder with self-circulation preheating of fuel gas as recited in claim 1, wherein the evaporative oil supply mechanism (3) comprises a first wall plate (302) extending obliquely downward and forming a first flow passage (4) with the rear wall (104), a second wall plate (303) arranged at the rear end of the first wall plate (302) and forming a second flow passage (5) with the shielding plate (2), and a third wall plate (304) extending from the front end of the first wall plate to the rear end of the shielding plate (2), and the first wall plate (302) and the second wall plate (303) are sealed by the third wall plate (304) to form an evaporation cavity (301).

3. The gas self-circulating preheated evaporative cavity flame holder as claimed in claim 2, wherein the first wall panel (302) is arranged parallel to the rear wall (104) and the second wall panel (303) is arranged parallel to the shielding panel (2).

4. The gas self-circulating preheated evaporative cavity flame holder as claimed in claim 1, wherein a plurality of said third flow channels (6) and a plurality of said fourth flow channels (7) are distributed along the transverse direction; the fourth flow channel is located above the third flow channel.

5. The gas self-circulating preheated evaporative cavity flame holder as in claim 4, wherein the third and fourth flow channels are staggered in the transverse direction.

6. The gas self-circulating preheated evaporative cavity flame holder as claimed in claim 1, wherein the front end of the cavity flame holder (1) is provided with a horizontally extending front duct splitter plate (8).

7. The gas self-circulating preheated evaporative cavity flame holder as claimed in claim 1, wherein the rear end of the protection plate (2) is provided with a horizontally extending rear duct splitter plate (9).

Technical Field

A flame stabilizer in an afterburner of a turbofan engine, a combustion chamber of a sub-combustion ramjet engine and a multi-duct combustion chamber of a turbofan/ramjet combined cycle engine, in particular to an evaporative cavity flame stabilizer for self-circulation preheating of fuel gas.

Background

A turbo-based combined cycle engine (TBCC) is regarded as the most promising hypersonic aircraft power device at the present stage as an air-breathing engine with the performance advantages of wide flight range, conventional take-off and landing, reusability and the like. The flow conditions of low incoming flow temperature and excessive local flow velocity inside the TBCC super combustor due to the characteristic that the bypass ratio varies greatly in the whole working range bring difficulties to ignition and flame stabilization inside the multi-mode combustor.

With the increase of the air flow speed and the decrease of the temperature of the incoming air in the modern high-performance combustion chamber, in order to ensure the reliable ignition performance of the combustion chamber and reduce the flow loss caused by a flame stabilizer, an on-duty flame stabilizer is generally adopted for soft ignition at the outer ring of the combustion chamber. The concave cavity flame stabilizer has the advantages of low resistance loss, good flame stabilizing performance, capability of enhancing main flow mixing and the like, and is a flame stabilizer with great potential under the condition of wide incoming flow.

In a liquid kerosene fueled subfire re-entrant flame holder, it is desirable for the kerosene to be rapidly atomized, vaporized and mixed with air in the re-entrant flame holder in order to improve the ignition performance of the combustion chamber. When the direct injection type nozzle is directly adopted to supply oil on the wall surface of the flame stabilizer with the concave cavity, due to poor atomization performance, fuel oil is easy to directly spray away from an on-duty area, the concentration of gas phase fuel oil in the area is low, ignition fails, or liquid drops are attached to the wall surface of the stabilizer to form carbon deposition, so that combustion and thermal protection are not facilitated; the smaller depth of the re-entrant flame holder is not suitable for use with centrifugal nozzles having a larger atomization cone angle. Therefore, the oil supply scheme of the concave cavity flame stabilizer using liquid kerosene as fuel needs to be optimally designed, so that the concave cavity flame stabilizer has wider lean oil ignition and flame stabilization performance to meet the use requirement of the modern high-performance engine combustion chamber when the incoming flow condition changes greatly.

Disclosure of Invention

The purpose of the invention is as follows: in order to solve the problems in the prior art, the invention provides a gas self-circulation preheating evaporation type concave cavity flame stabilizer.

The technical scheme is as follows: the invention relates to a fuel gas self-circulation preheating evaporative cavity flame stabilizer which comprises a cavity flame stabilizer, wherein the cavity flame stabilizer is provided with a cavity, a front wall, a main plate and a rear wall which enclose the cavity, the rear end of the rear wall horizontally extends to form a protection plate, an evaporative oil supply mechanism is arranged above the protection plate, the evaporative oil supply mechanism is provided with an evaporation cavity communicated with an oil injection device, a first flow passage for introducing an outer duct airflow is formed between the evaporative oil supply mechanism and the rear wall, a second flow passage communicated with the first flow passage is formed between the evaporative oil supply mechanism and the protection plate, and the first flow passage and/or the second flow passage are/is provided with an airflow outlet; and a plurality of third flow channels for sending gas in the cavity into the evaporation cavity and a plurality of fourth flow channels for sending out premixed oil gas in the evaporation cavity are arranged between the cavity and the evaporation cavity.

The evaporative oil supply mechanism comprises a first wall plate, a second wall plate and a third wall plate, wherein the first wall plate extends obliquely downwards and forms a first flow channel with the rear wall, the second wall plate is arranged at the rear end of the first wall plate and forms a second flow channel with the protection plate, the third wall plate extends from the front end of the first wall plate to the rear end of the protection plate, and an evaporation cavity is formed between the first wall plate and the second wall plate through the sealing of the third wall plate.

The first wall plate and the rear wall are arranged in parallel, and the second wall plate and the protection plate are arranged in parallel.

A plurality of third flow channels and a plurality of fourth flow channels are distributed along the transverse direction; the fourth flow channel is located above the third flow channel.

The third flow channels and the fourth flow channels are distributed in a staggered mode along the transverse direction.

And a front duct splitter plate extending horizontally is arranged at the front end of the concave cavity flame stabilizer.

The rear end of the protection plate is provided with a horizontally extending rear duct splitter plate.

Has the advantages that: (1) the invention adopts the way of preheating the kerosene by self-circulation of fuel gas through the evaporation type oil supply mechanism and the flow channel formed between the evaporation type oil supply mechanism and the concave cavity to accelerate the atomization and evaporation of the liquid kerosene and improve the ignition and flame stability performance of the combustion chamber; (2) according to the invention, through the evaporation type oil supply mechanism and the flow channel formed between the evaporation type oil supply mechanism and the concave cavity, the fuel gas is self-circulated, the gas is not required to be led from the outer culvert, the complexity of the flow channel design between the inner culvert and the outer culvert is reduced, and the outer culvert has higher cold gas amount to carry out heat protection on hot end parts because the air is not required to be supplied to the inner culvert; (3) the evaporative oil supply mechanism is arranged close to the concave cavity, so that the oil-gas premixed gas is sprayed in from the downstream line of the rear wall surface of the concave cavity, the fuel can reach any ignition position through the downstream line, and the arrangement range of the ignition electric nozzle is widened; (4) the evaporation cavity structure in the evaporation type oil supply mechanism reduces the airflow expansion angle when the bypass airflow flows through the rear wall of the concave cavity from the concave cavity main board, avoids airflow flow separation, and reduces the flow loss of a combustion chamber; (5) the shell on the periphery of the evaporation cavity forms a stable triangular structure, plays a role of reinforcing ribs for the flame stabilizer of the concave cavity, and can strengthen the structural reliability of the hot end part.

Drawings

FIG. 1 is a three-dimensional model of an evaporative cavity flame stabilizer with self-circulating preheating of fuel gas according to the present invention;

FIG. 2 is a schematic view of an evaporative oil supply mechanism according to the present invention;

FIG. 3 is a top view of an evaporative cavity flame stabilizer with self-circulating preheating of fuel gas;

FIG. 4 is a schematic flow diagram of the present invention at a third flow channel cross-section and a fourth flow channel mid-section;

FIG. 5 is a schematic flow diagram of the present invention at a fourth flow channel cross-section and a third flow channel intermediate cross-section;

FIG. 6 is a streamline distribution in an evaporative cavity flame holder with gas self-circulation preheat calculated using Fluent software.

Detailed Description