WO2021107417A1

WO2021107417A1 - Combustion device capable of maximizing combustor's operation efficiency and exhaust performance

Info

Publication number: WO2021107417A1
Application number: PCT/KR2020/014835
Authority: WO
Inventors: 이기만; 김민국; 강연세; 안지환; 김경모
Original assignee: 순천대학교 산학협력단
Priority date: 2019-11-25
Filing date: 2020-10-28
Publication date: 2021-06-03
Also published as: JP7270111B2; KR102096749B1; JP2022548420A

Abstract

The present invention relates to a combustion device capable of maximizing a combustor's operation efficiency and exhaust performance and, more specifically, to a combustion device comprising: a gas nozzle unit that allows gas fuel to be supplied; a gas fuel distribution unit that is in communication with the gas nozzle unit to form a space and distributes gas fuel; a first mixing chamber that is in communication with the gas fuel distribution unit through a first through-hole to form a space in which gas fuel is premixed with air; a second mixing chamber that is in communication with the gas fuel distribution unit through a second through-hole to form a space in which gas fuel is premixed with air; a turbulence producing nozzle unit provided between the first mixing chamber and the second mixing chamber to produce a turbulent flow of a pre-mixture of gas fuel and air that are premixed in the first mixing chamber; and a swirl nozzle unit that is in communication with an air nozzle unit to allow air for combustion to be supplied into each of the first mixing chamber and the second mixing chamber. The swirl nozzle unit comprises: a first flow path that is in communication with the first mixing chamber to allow gas fuel ejected through the first through-hole to come into perpendicular contact and be mixed with swirling air; and a second flow path that is in communication with the second mixing chamber to allow gas fuel ejected through the second through-hole to come into perpendicular contact and be mixed with air having a lower swirl number than that in the first flow path. The turbulence producing nozzle unit comprises: a block-type turbulence producing unit including a plurality of grid holes having a fractal shape to induce a turbulent flow of the pre-mixture of gas fuel and air that are premixed in the first mixing chamber, and a cylindrical internal nozzle unit that allows the pre-mixture of gas fuel and air passing through the turbulence producing unit to flow into a combustion chamber, wherein the turbulence producing unit has an elongated form along the length direction of the internal nozzle unit and maintains rigidity, even when flames adhere thereto due to flash back, to enable continuous combustion, thus increasing combustion efficiency.

Description

Combustion device that can maximize combustor operation efficiency and emission performance

The present invention is a combustion device capable of maximizing combustor operation efficiency and exhaust performance. More specifically, turbulence intensity without forming a high-temperature inner recirculation zone in the combustion field through the improvement of the double flow path system. ) is strengthened to reduce the residence time of high-temperature combustion products in the flame during combustion, thereby suppressing the generation of harmful substances such as nitrogen oxides sensitive to the residence time of combustion products. In case of possible flash-back, the operation of the entire combustion system is minimized due to the damage of structurally weak parts in the turbulence generator with enhanced turbulence intensity, thereby increasing the operation efficiency of the combustion apparatus and improving the operation efficiency and emission performance of the combustion apparatus. It relates to the turbulence generating grid structure of the combustion device that can maximize the

Nitrogen oxide (NOx) is a compound of nitrogen and oxygen and refers to NO, NO2, NO3, N20, N2O3, N2O4 and N2O5. Of these, NO and NO2 are classified as the most serious air pollutants because they are emitted in large amounts when fossil fuels are burned using combustion air. NOx refers to all nitrogen oxides, but generally refers to NO and NO2 in the field of air pollution. Nitrogen oxides are mainly emitted during the combustion process of fossil fuels. During combustion, condensable fine dust (PM 2.5), which is discharged from gaseous state and condensed through a photochemical reaction, is converted into ultra-fine dust (PM 2.5), which is a major social issue. It is known as the main culprit of CPM), and it is also a substance that has been recently added as a pollutant subject to the air emission charge by the government. Unlike general fine dust (PM 10), which has a diameter of about 10 µm, ultra-fine dust is about 2.5 µm in diameter, which is 1/30 of a human hair. It is also a group 1 carcinogen designated by the International Agency for Research on Cancer under the World Health Organization (WHO).

Most of the nitrogen oxide emission standards are based on the assumption that NO is oxidized to NO2. NOx, a nitrogen oxide that is inevitably generated during fossil fuel combustion, is a precursor of nitrate, a kind of condensable ultrafine dust. ), is a representative atmospheric pollutant that is generated in a gaseous state from a combustion device and released into the atmosphere and then condensed through a photochemical smog reaction with water vapor, ozone, and ammonia to develop into solid fine dust. Therefore, it is very important to reduce the amount of harmful substances such as nitrogen oxides generated during combustion.

For example, Korean Patent Publication No. 10-0016168 (July 23, 1997) discloses a technique related to a control method for reducing nitrogen oxides in a flue gas stream. Looking at the technical characteristics of the method for controlling the reduction of nitrogen oxides in the flue gas stream, nitrogen oxides are removed step by step with a nitrogen-containing treatment agent or selective catalytic reduction treatment (SCR). However, most of the technologies are designed for post-treatment after combustion, such as the need to move the harmful gas generated after combustion to a separate device and the need for a separate treatment material for nitrogen oxide treatment. There is a problem that the oxide cannot be reduced.

In addition, in Japanese Unexamined Patent Application Publication No. Hei 09-170716, in addition to swirling the mixed flow of gas fuel and air, turbulence is generated with a turbulent plate disposed downstream of the fuel nozzle to reduce the mixing distance of the mixed flow and reverse flow and backflow. and a feature for preventing the occurrence of a high-temperature region. However, in the prior art, there is a problem that the strength is very weak because the configuration for generating turbulence is formed of a thin plate. For example, during combustor operation, the flow rate of the combustor varies greatly depending on the load change. In particular, when the speed of the gas fuel and air mixture decreases at a low load, a flash-back phenomenon occurs, in which the flame burns into the injection nozzle. The flame attaches to the inside of the nozzle and damages or breaks important parts of the combustor nozzle, such as the turbulence plate or swirler, causing fatal losses that stop the operation of the entire combustion system. Structurally, the plate-type turbulence generator configuration is concerned about thermal damage to the nozzle part when backfired, so the combustor operation is stopped and operated after inspection, or serious damage due to radiant heat from a high-temperature flame is caused by continuous operation for a long time even when there is no backfire. and, accordingly, there was a problem that continuous replacement was required after a certain period of time.

The present invention has been devised to solve the problems of the prior art as described above, and while reducing the amount of harmful gas generated during combustion through complete combustion of the combustion device in the combustion process rather than the post-combustion treatment technology, the efficiency of the combustion device is improved. It is aimed at maximizing

In addition, an object of the present invention is to maximize the durability, reliability and safety of the combustion device while increasing the operating efficiency by minimizing the stoppage of the combustion device due to a change in load, particularly a flashback phenomenon that may occur at a low load. . For example, in gas turbine combustors for power generation and aviation, very small fragments destroyed from the combustor nozzle in the turbine, a rotating body rotating at high speed at hundreds of thousands of revolutions per minute (RPM) at the rear end of the combustor, are like a bird collision in an aircraft engine. It aims to prevent fatal damage to the entire gas turbine system such as strike).

In addition, the present invention enhances the flame stabilizing function of the turbulent flame by increasing the turbulence intensity through the fractal-shaped turbulence generator in maintaining the structurally robust fractal-shaped turbulence generator, and The purpose of this is to effectively suppress combustion harmful substances such as nitrogen oxides by reducing the residence time of high-temperature combustion products by suppressing the generation of the inner recirculation zone in the salting.

In addition, the present invention aims to improve the pre-mixing performance of gas fuel through a double orthogonal flow structure and a double orthogonal flow structure because the harmful gas of nitrogen oxides has a property that depends on the mixing performance between air and fuel before combustion.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems to be solved by the present invention not mentioned here are to those of ordinary skill in the art to which the present invention belongs from the description below. can be clearly understood.

In the combustion apparatus capable of maximizing the combustor operation efficiency and emission performance according to a preferred embodiment of the present invention, a gas nozzle for supplying gas fuel and a space are formed in communication with the gas nozzle, and gas fuel The gas fuel distribution unit for distribution communicates with the gas fuel distribution unit by the first through hole to form a space in which gas fuel is premixed with air, and the gas fuel distribution unit communicates with the second through hole It is provided between the second mixing chamber and the first mixing chamber and the second mixing chamber to form a space in which the gas fuel is premixed with air, and the premix of the gas fuel and air premixed in the first mixing chamber is turbulent. and a swirling nozzle in communication with the turbulence generating nozzle and the air nozzle to supply combustion air to the first and second mixing chambers, respectively, wherein the orbiting nozzle communicates with the first mixing chamber. A first flow path through which the gas fuel injected through the first through-hole can be mixed in vertical contact with the swirled air and the gas fuel injected through the second through-hole communicated with the second mixing chamber is the and a second flow path for vertically contacting and mixing with air having a lower degree of rotation than the first flow path, and the turbulence generating nozzle unit is provided with a plurality of fractal-shaped lattice holes to form an example in the first mixing chamber. a block-shaped turbulence generating unit for inducing turbulent flow of the mixed gas fuel and air mixture; and a cylindrical inner nozzle unit for allowing the pre-mixture of gas fuel and air that has passed through the turbulence generating unit to flow into the combustion chamber; The turbulence generator is formed long in the longitudinal direction of the inner nozzle part and structurally maintains the rigidity of the material even when a flame is attached by a flashback phenomenon, thereby enabling continuous combustion operation without damage to the grids, thereby improving the safety of the system and the combustion efficiency of the combustor. characterized by increasing.

By means of a solution to the above problem, the combustion device capable of maximizing the combustor operation efficiency and emission performance of the present invention minimizes the stoppage of the combustion device due to a change in load, in particular, a backfire that may occur at a low load. , it is effective in securing the safety of the entire combustion system and maximizing the efficiency of the combustion apparatus.

In addition, the fractal-shaped turbulence generator and low vortex structure suppress the formation of the internal recirculation region in the combustion device, thereby reducing the amount of harmful gases that are closely related to the residence time of high-temperature combustion products such as thermal NOx (nitrogen oxide) during combustion. It is effective in reducing the amount of production.

In addition, since nitrogen oxides are closely related to the mixing performance of fuel and combustion air, the present invention has a mixing structure that maintains a double swirl structure, an orthogonal flow structure, and a fractal-shaped turbulence generating unit structure, thereby premixing gas fuel and air. It has an excellent effect in improving the premixing performance of

1 is a cross-sectional view of a combustion device capable of maximizing the combustion efficiency and emission performance of a combustor according to a first embodiment of the present invention.

FIG. 2 shows an example of a turbulence generator of a combustion device capable of maximizing the combustion efficiency and emission performance of the combustor according to the first embodiment of the present invention.

3 is a view showing another embodiment of the turbulence generator of the combustion device capable of maximizing the combustor operation efficiency and emission performance according to the first embodiment of the present invention.

4 shows another embodiment of the turbulence generating unit of the combustion apparatus capable of maximizing the combustion efficiency and the exhaust performance of the combustor according to the first embodiment of the present invention.

5 is a view showing the pre-mixing action of the combustion device capable of maximizing the combustor operation efficiency and emission performance according to the first embodiment of the present invention.

6 is a view showing the pre-mixing action of the combustion device capable of maximizing the combustor operation efficiency and emission performance according to the first embodiment of the present invention.

7 is a view showing the pre-mixing action of the combustion device capable of maximizing the combustor operation efficiency and emission performance according to the first embodiment of the present invention.

8 is a view showing the results of an operation performance experiment of a combustion device capable of maximizing the combustion efficiency and emission performance of the combustor according to the first embodiment of the present invention.

9 is a view showing the results of measurement of the amount of harmful substances generated by the combustion device capable of maximizing the combustor operation efficiency and emission performance according to the first embodiment of the present invention.

10 is a view showing a turbulence generating unit of a combustion device capable of maximizing the combustor operation efficiency and emission performance according to the second embodiment of the present invention.

11 is a view showing a turbulence generating unit of a combustion device capable of maximizing the combustion efficiency and emission performance of the combustor according to the third embodiment of the present invention.

12 is a view showing a turbulence generating unit of a combustion device capable of maximizing the combustor operation efficiency and emission performance according to the fourth embodiment of the present invention.

Terms used in this specification will be briefly described, and the present invention will be described in detail.

The terms used in the present invention have been selected as currently widely used general terms as possible while considering the functions in the present invention, which may vary depending on the intention or precedent of a person skilled in the art, the emergence of new technology, and the like. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, rather than the name of a simple term.

In the entire specification, when a part “includes” a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the embodiments of the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

Specific details including the problem to be solved for the present invention, the means for solving the problem, and the effect of the invention are included in the embodiments and drawings to be described below. Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

As shown in Figs. 1 and 2, the combustion apparatus capable of maximizing the combustor operation efficiency and exhaust performance according to the first preferred embodiment of the present invention includes a gas nozzle unit 10 to which gas fuel is supplied and the gas nozzle. The gas fuel distribution unit 20 communicates with the unit 10 to form a space and the gas fuel distribution unit 20 communicates with the first through hole 21 to form a space in which the gas fuel is premixed with air. The first mixing chamber 22 and the second mixing chamber 24 communicated with the gas fuel distribution unit 20 and the second through hole 23 to form a space in which the gas fuel is premixed with air, and the The turbulence generating nozzle part 30 and the air nozzle part are provided between the first mixing chamber 22 and the second mixing chamber 24 so that the gas fuel premixed in the first mixing chamber 22 flows in a turbulent flow. and a turning nozzle unit 40 communicating with 50 to supply combustion air to the first mixing chamber 22 and the second mixing chamber 24, respectively.

In addition, the orbiting nozzle unit 40 communicates with the first mixing chamber 22 so that the gas fuel injected through the first through hole 21 is in vertical contact with the swirled air to be mixed. The first flow passage 41 communicates with the second mixing chamber 24 and the gas fuel injected through the second through hole 23 is in vertical contact with air having a lower degree of rotation than the first flow passage 41 . and a second flow path 42 for mixing.

Accordingly, the gas fuel and air premixed through the first mixing chamber 22 are mixed with the gas fuel premixed through the second mixing chamber 24 through the turbulence generating nozzle unit 30 . While being mixed with the pre-mixer of air, the ignition is maintained in a state of maintaining turbulent flow due to the pre-mixer slightly swirling through the second mixing chamber 24, thereby suppressing the formation of an internal recirculation region in the flame, and combustion products at high temperature By reducing the residence time, the generation of harmful substances is minimized.

That is, the first gas fuel injected through the first through hole 21 from the gas fuel distribution unit 20 is provided at the end of the orbiting nozzle unit 40 in communication with the air inlet unit 51 . The air for combustion strongly swirled through the flow path 41 is mixed while collided with it at right angles. In addition, a portion of the combustion air in which the gas fuel distribution unit 20 communicates with the second through hole 23 and the gas fuel is introduced from the air inlet unit 51 is located at the center of the orbiting nozzle unit 40 . In the second flow path 42 provided in the , it meets and mixes with the swirling flow, which is relatively weak compared to the first flow path 41 . Through this, the pre-mixed gas fuel in the flame generated by a separate ignition device (not shown) at the outlet of the orbiting nozzle unit 40 by the pre-mixed gas fuel and air is transferred to the internal recirculation area (IRZ). , Inner Recirculation Zone) is created to reduce the residence time of combustion products at high temperatures, thereby minimizing the generation of harmful substances such as thermal nitrogen oxides that are generated in proportion to the residence time.

In addition, the turbulence generating nozzle unit 30 is in the form of a circular block, and a plurality of fractal-shaped grids are provided throughout, and through this, pre-mixed in the first mixing chamber 22 . A turbulence generating unit 31 for inducing a turbulent flow of the gas fuel and air premixer, and a cylindrical inner nozzle unit for allowing the gas fuel and air premixture that has passed through the turbulence generating unit 31 to flow into the combustion chamber ( 32). In addition, the turbulence generating unit 31 is formed to have a predetermined thickness in the form of a cylindrical block, and structurally maintain the rigidity of the material even when a flame is attached by a flashback phenomenon, thereby enabling continuous combustion operation without damage to the grids. In addition to securing the safety of the system, the combustion efficiency should be increased.

First, the combustion device capable of maximizing the combustion efficiency and exhaust performance according to the present invention is provided with the gas nozzle unit 10 . The gas nozzle unit 10 serves to guide external gas fuel to be supplied to the gas fuel distribution unit 20 .

The gas fuel distribution unit 20 is provided at an end of the gas nozzle unit 10 . The gas fuel distribution unit 20 has a predetermined space therein, and serves to distribute the gas fuel flowing in from the gas nozzle unit 10 . In more detail, the gas fuel distribution unit 20 is provided in a cylindrical shape, and a plurality of the first through holes 21 are provided at one end of the gas fuel distribution unit 20 based on a cross section. The first through hole 21 communicates with the gas fuel distribution unit 20 and the first mixing chamber 22 so that the gas fuel supplied from the gas nozzle unit 10 passes through the first mixing chamber 22 . to be able to move to At this time, the gas fuel injected from the gas fuel distribution unit 20 through the first through-hole 21 is combined with a strong swirling motion of the combustion air introduced through the first flow path 41 in the first flow path ( 41), it is mixed with the combustion air while collided in a right-angled flow form (Jet in cross) and moved into the first mixing chamber 22 .

Next, a plurality of the first through-hole 21 and the second through-hole 23 are arranged radially around the center of the turbulence generating nozzle, respectively. In addition, the first through hole 21 is located at the same distance from the center with respect to the cross section of the gas fuel distribution unit 20 . In more detail, the second through hole 23 does not interfere with the first flow path 41 and is formed to communicate with the second flow path 42 provided in the central portion of the orbiting nozzle unit 40 . In this case, the second flow passage 42 is configured at a turning angle that enables a weaker turning motion compared to the first flow passage 42 . Accordingly, the second through hole 23 communicates with the gas fuel distribution unit 20 and the second mixing chamber 24 so that the gas fuel supplied from the gas nozzle unit 10 passes through the second flow path 42 . ) is pre-mixed with the combustion air that has passed so that it can be moved to the second mixing chamber 24 . In addition, the second through hole 23 is located at the same distance from the center with respect to the cross section of the gas fuel distribution unit 20 . That is, the first through-hole 21 and the second through-hole 23 are arranged in a circle spaced apart from each other by a predetermined distance with respect to the center of the turbulence generating nozzle unit 30 , respectively.

Next, the first through hole 21 and the second through hole 23 are provided in a zigzag form with respect to the center of the gas fuel distribution unit 20 . That is, the gas fuel supplied from the gas nozzle unit 20 is uniformly distributed from the gas fuel distribution unit 20 to the first mixing chamber 22 and the second mixing chamber 24 , respectively. . In addition, the number of the first through hole 21 and the second through hole 23 is preferably provided to be the same. This is also so that the gas fuel supplied from the gas nozzle 10 can be uniformly distributed from the gas fuel distribution unit 20 to the first mixing chamber 22 and the second mixing chamber 24 . . In addition, according to the amount of gas fuel and air, the diameters of the cross-sections of the first through hole 21 and the second through hole 23 are adjusted to the first mixing chamber 22 and the second mixing chamber 24 . It is possible to control the flow rate of the gas fuel supplied. In addition, it is possible to achieve important combustion stabilization in lean combustion such as a gas turbine combustor by always supplying a constant amount of gas fuel regardless of pressure fluctuations in the combustion chamber 52 during combustion.

Specifically, the diameter of the first through hole 21 and the second through hole 23 is a condition for gas fuel to become a choking flow, and the first through hole 21 and the second through hole 23 ) The pressure difference between the front and rear ends, for example, is manufactured to be maintained at 1.6 atm or more in the case of LNG fuel. At this time, if the diameters of the first through-hole 21 and the second through-hole 23 are set so that the pressure difference is 1.6 atm or more, the first through-hole 21 and the second through-hole 23 The injected gas fuel forms a choking flow with a Mach number of 1.0. Therefore, even after the pre-mixer flow ejected from the orbiting nozzle unit 40 is ignited and combusted at the outlet of the orbiting nozzle unit 40, it is not affected by the pressure change inside the combustion chamber 52 and is stable and stable. It becomes possible to form a uniform mixer.

Next, the first mixing chamber 22 and the second mixing chamber 24 are provided. The first mixing chamber 22 has a space therein, and communicates with the gas fuel distribution unit 20 through the first through hole 21 . Accordingly, the combustion air introduced through the air nozzle unit 50 is introduced through the first flow path 41 and is adjacent to the outlet of the first flow path 41 inside the first mixing chamber 22 . While striking at right angles to the gas fuel, it is strongly swirled and pre-mixed.

In addition, the second mixing chamber 24 has a space therein, and communicates with the gas fuel distribution unit 20 through the second through hole 23 . Also in this case, the combustion air introduced through the air nozzle unit 50 is introduced through the second flow path 42 and is adjacent to the outlet of the second flow path 42 inside the second mixing chamber 24 . It is rotated while colliding with the gas fuel at a right angle.

Next, the turbulence generating nozzle unit 30 is provided between the first mixing chamber 22 and the second mixing chamber 24 . In more detail, the turbulence generating nozzle unit 30 is provided with a plurality of square lattice holes having a plurality of fractal shapes in a circular block shape as shown in FIG. 2 , so that the gas fuel and air pre-mixed in the first mixing chamber 22 . A turbulence generating unit 31 for inducing a turbulent flow of the premixer and an inner nozzle unit 32 for allowing the premixed gas fuel and air that have passed through the turbulence generating unit 31 to flow into the combustion chamber 52. include First, the turbulence generator 31 has a cylindrical shape and is formed to be elongated along the longitudinal direction of the inner nozzle part 32, so that even if a flame is attached by a flashback phenomenon, it structurally maintains the rigidity of the material, so that the lattice is continuously burned without damage. By enabling operation, it is possible to secure the safety of the system and to increase the combustion efficiency. More specifically, the turbulence generating nozzle unit 30 is in the form of a pipe nozzle, and a turbulence generating unit 31 having a thickness in the form of a circular block is provided therein. The turbulence generator 31 functions to turbulence the premixed gas fuel and air premixed in the first mixing chamber 22 . That is, the turbulence performance (turbulence intensity) is greatly increased as the gas fuel and air premixer passes through the plurality of square lattice holes having a fractal shape of the turbulence generator 31 .

In addition, the length of the turbulence generating part 31 is formed to be about 0.3 to 0.6 times the length of the inner nozzle part 32 . At this time, when the thickness in the longitudinal direction of the turbulence generating unit 31 is formed to be less than 0.3 times the thickness in the longitudinal direction of the inner nozzle unit 32, a flashback phenomenon occurs at a change in load, especially at a low load, resulting in a combustor nozzle As the flame is attached to the inside, damage or breakage occurs in the turbulence generating unit 31 . For this reason, there is a problem in that the operation of the combustion device is stopped and the thermal efficiency is rapidly reduced. In addition, when applied to a combustor such as a gas turbine for power generation or aviation, small fragments destroyed from the combustor nozzle may cause fatal damage to the entire gas turbine system, such as a bird strike of an aircraft engine. And, when the thickness in the longitudinal direction of the turbulence generating unit 31 exceeds 0.6 times the thickness in the longitudinal direction of the inner nozzle unit 32, premixing passes through the hole of the turbulence generating unit 31. Since the turbulence performance of the mixed mixer is remarkably reduced, thermal efficiency is reduced, and there are problems in that the amount of harmful substances such as nitrogen oxide (NOx) is increased. In addition, the length of the flame becomes longer due to the reduced turbulence performance, and accordingly, it is necessary to design the combustion chamber to further increase the size, so there is a problem in that the overall size of the combustion device system is increased. Accordingly, the thickness in the longitudinal direction of the turbulence generating part 31 is 0.3 to 0.6 times the thickness in the longitudinal direction of the inner nozzle part 32 .

In addition, it is preferable that a guide unit 60 for guiding the premix of gas fuel and air premixed in the first mixing chamber 22 to flow to the turbulence generating unit 31 is provided.

In addition, the turbulence generator 31 may be formed in a fractal structure. The fractal structure is a structure that effectively increases the turbulence intensity. It is a structure in which a small shape is repeated endlessly in a shape similar to the overall shape to form the overall shape. Although the fractal structure is geometrically the same shape according to a certain rule, as the size and arrangement are arranged in different shapes, the fluid passing through such a fractal structure generates various turbulence lengths and energy to increase the turbulence intensity. It is a structure that can be effectively increased. In such a fractal structure, the thickness of the fractal grid decreases according to the law of a constant ratio. When the turbulence generator 31 is formed in a fractal structure and the rate of decrease in the thickness of the fractal lattice is 0.6 or less, the turbulence intensity is 2 to 3 times higher than that of the turbulence generator 31 having the radial hole. will increase twice Therefore, when the turbulence generator 31 is configured with such a fractal structure, the turbulence intensity can be effectively increased.

2 to 4, the turbulence generating unit 31 increases the turbulence intensity of the pre-mixer by allowing the pre-mixer to pass through the main body 32a supporting the turbulence generating unit 31. It includes a fractal hole portion (32b). In this case, the body portion 32a and the fractal hole portion 32b may have different lengths in the longitudinal direction of the turbulence generator 31 .

More specifically, referring to FIG. 3 , the length of the fractal hole 32b becomes shorter and shorter from the center of the turbulence generator 31 toward the outer circumferential surface. Therefore, even if the end of the main body 32a is damaged by a flame attached to the end of the main body 32a when a flashback phenomenon occurs at a change in load, particularly at a low load, the fractal hole 32b turbulence of the pre-mixer, so that it does not affect the In other words, by preventing the flame from damaging the fractal hole 32b, the turbulence intensity increase rate of the premixer passing through the turbulence generator 31 can be continuously maintained. As a result, there is an advantage in that the rigidity of the turbulence generating unit 31 can be increased while maintaining the thermal efficiency of the combustion device.

Also, referring to FIG. 4 , the length of the fractal hole 32b is longer than the length of the body portion 32a. Accordingly, as the time for the premixer to pass through the fractal hole 32b increases, there is an advantage that the turbulence intensity of the premixer can be further increased.

Next, the ignition device may be provided at the outlet of the orbiting nozzle unit 40 communicating with the combustion chamber 52 to be driven by a separate power source. That is, the ignition device ignites the pre-mixture of unburned gas fuel and air injected from the outlet of the orbiting nozzle unit 40 to form a flame field without the internal recirculation region IRZ in the combustion chamber 52 .

Next, the air nozzle part 50 and the orbiting nozzle part communicated with the air inlet part 51 so that combustion air can be supplied to the first mixing chamber 22 and the second mixing chamber 24 . (40) is provided. In more detail, the air nozzle unit 50 is provided in a shape surrounding the outer peripheral surfaces of the first mixing chamber 22 and the second mixing chamber 24 . In addition, a space is provided between the air nozzle part 50 and the orbiting nozzle part 40 through which air can flow by communicating with the first mixing chamber 22 and the second mixing chamber 24 . Accordingly, the air inlet 51 includes a pre-mixer of gas fuel and air in the first mixing chamber 22 and the second mixing chamber 24 and a first flow path provided on one side of the orbiting nozzle unit 40, respectively. It serves to supply air to be mixed with the combustion air introduced through the 41 and the second flow path 42 .

That is, the orbiting nozzle unit 40 communicates with the first mixing chamber 22 to provide a first flow path 41 and the second mixing chamber for supplying air of a strong swirling flow to the first mixing chamber 22 . It is preferable to be provided as a second flow path 42 communicating with the 24 and supplying air to the second mixing chamber 24 with a weak swirling flow with a swirling strength of 0.4 to 0.55.

In addition, the first through hole 21 is positioned directly in front of the exit of the first passage 41 , and the second through hole 23 is located on one side of the inner wall of the second passage 42 . Accordingly, the gas fuel supplied through the first through hole 21 and the combustion air supplied as a strong swirling flow through the first flow path 41 collide with an orthogonal jet flow advantageous for mixing. This is to enable efficient premixing. Similarly, the gas fuel supplied through the second through hole 23 is to be efficiently premixed with the combustion air having a weak turning strength supplied through the second flow passage 42 .

Hereinafter, the operation of the combustion device capable of maximizing the combustor operation efficiency and emission performance according to the present invention will be described in detail with reference to FIGS. 1 to 5 .

First, when the combustion device is operated, gas fuel is introduced into the gas fuel distribution unit 20 from the gas nozzle unit 10 , and the supplied gas fuel is supplied from the gas fuel distribution unit 20 to the first through hole. The first mixing chamber 22 and the second mixing chamber 24 are divided and moved by the 21 and the second through-hole 23 . At this time, in the first mixing chamber 22 and the second mixing chamber 24 , the combustion air supplied through the air nozzle unit 50 and the orbiting nozzle unit 40 and the first through hole 21 . And the gas fuel supplied through the second through hole 23 is pre-mixed. Thereafter, the mixer in a state of weak turning intensity in the second mixing chamber 24 is moved to the combustion chamber 52 while maintaining a weak turning motion around the mixer premixed with a strong turning intensity in the first mixing chamber 22 . do. In this state, it is ignited by the ignition device to form a high-temperature turbulent premixed flame in the combustion chamber 52 .

At this time, a large amount of harmful substances such as thermal NOx is generated due to the high-temperature flame. A method of reducing the generation of harmful substances such as thermal NOx is to lower the temperature of the flame or to reduce the residence time during which the high-temperature combustion products in the flame stay in the flame field, which is the reaction field. However, in the case of a gas turbine, it is most effective to increase the turbine inlet temperature (TIT) in order to improve the thermal efficiency of the system. Since it is an essential requirement for all gas turbine combustors in recent years, in the case of lowering the flame temperature among the above methods, the thermal efficiency of the entire gas turbine system is lowered, so the high temperature combustion products stay in the flame without lowering the flame temperature. Saving time is the best way.

Accordingly, in the first mixing chamber 22 , the strong swirling flow of the first flow path 41 meets the gas fuel injected from the first through hole 21 in a vertical jet form (Jet in cross) to premix. do. Thereafter, the turbulence is generated while passing through the turbulence generating unit 31 mounted inside the turbulence generating nozzle unit 30 communicating with the first mixing chamber 22 . Thereafter, at the end of the turbulence generating nozzle unit 30, it passes through the second mixing chamber 22 and meets with the mixer premixed by a weak swirling flow. Thereafter, a premixed flame is formed at the outlet of the orbiting nozzle unit 40 in communication with the combustion chamber 52 . That is, the recirculation region does not occur in the central portion of the flame, and the flame approaches complete combustion. A premix of gas fuel and air premixed in the first mixing chamber 22 is strongly turbulent as it passes through the turbulence generator 31 . At this time, the premix of gas fuel and air premixed in the first mixing chamber 22 is prevented from being generated by a rapid expansion flow in the combustion chamber 52 . That is, the premix of the gas fuel and air premixed in the second mixing chamber 24 is prevented from spreading outwardly from the premixed gas fuel and air premixed in the first mixing chamber 22 . That is, the pre-mixed gas fuel and air pre-mixed in the first mixing chamber 22 injected into the combustion chamber 52 is protected from the weak rotational motion from the second flow passage 42 while maintaining strong turbulent flow. It will be moved to the combustion chamber 52 as one. Due to this, it minimizes the formation of the internal recirculation region of the flame field generated in the combustion chamber 52, and reduces the residence time of the high-temperature combustion product in the flame field, such as thermal nitrogen oxides, which are closely related to the residence time. It is possible to minimize the generation of harmful substances.

Hereinafter, an experiment comparing the combustion performance according to the thickness of the turbulence generating part of the combustion device capable of maximizing the combustor operation efficiency and emission performance according to the present invention and the amount of nitrogen oxide generated, which is a representative combustion pollutant, will be described.

As the experimental method, first, considering that the main component of LNG gas fuel is methane (CH ₄ ), high-purity methane gas having a purity of 99.95% was used as fuel to increase the precision of the experimental results. In addition, according to the thermal power of the lab-scale combustor considering the laboratory-scale flow rate, it is determined whether the combustor can be operated normally even in a lean state with a relatively large amount of oxidant (air). The lean flammability limit performance is shown by the equivalence ratio, which is the fuel-oxidizer (air) mixing ratio, and the adiabatic flame temperature of the corresponding equivalence ratio under the mixing conditions (temperature, pressure). 8 is indicated. In addition, in order to suppress the generation of nitrogen oxides (NOx), most of the recent low-emission combustors are operated in a state of lean combustion in which the fuel-oxidizer mixing ratio is lean like a lean burn engine of a car. (Stoichiometric ratio) was measured while lowering the emission concentration of NOx, which is nitrogen oxide, to less than 1.0, _{and the concentration value converted into 15% oxygen (O 2} ) concentration, which is the exhaust gas emission standard of the gas turbine combustor, is shown in FIG. 9 .

As a result of the experiment, referring to FIGS. 8 and 9 , as the thickness of the turbulence generator 31 increases, the equivalence ratio value corresponding to the lean flammability limit value similarly to the TDR (Turn down ratio) performance, which is the operable heat capacity range of the combustion device. As this relatively increases, it can be seen that the stable flame region in which the combustor can burn fuel even at a low equivalence ratio is reduced. In particular, in the case of a combustor of a gas turbine system, such a reduction in the operation range of the combustor lowers the performance factor of the gas turbine combustor, Lean blow-off (LBO), and the amount of pollutants such as nitrogen oxide (NOx) It can be seen that this increases slightly. However, in the case of the plate-shaped turbulence generating unit 31 having a thickness of 1 mm, when the load is changed, especially at a low load (heat capacity), the flame burns into the nozzle and a backfire occurs, so that the flame in the turbulence generating nozzle unit 30 occurs. In the case of attachment, as the turbulence generating function deteriorates as the thin grid connecting bar or grid fragments are damaged due to deterioration by the attached flame, the combustion performance is remarkably reduced and the operation of the combustion device must be stopped this will happen Even in the case of a combustor of a gas turbine system, broken (lattice) pieces from the combustor nozzle collide with the rotor blades at the rear end of the combustor rotating at high speed like a bird strike in an aircraft engine. It causes fatal damage to the turbine engine. That is, the combustion device using the turbulence generating unit 31 having a plate shape as thin as 1 mm in thickness is repeatedly stopped, resulting in energy loss and a sharp decrease in operating performance and combustor reliability. On the contrary, in the case of the turbulence generator 31 formed to have a thickness of 12.5 mm and 25 mm, the combustion device can be continuously operated because it has the strength to continuously operate even when the flame is attached due to a flashback phenomenon. As a result, as the thickness of the turbulence generator 31 increases, the operating range of the lean flammability limit and combustion exhaust gas emission performance, which is the downward combustion stabilization region of the combustion device, decrease slightly, but the combustion device that is always exposed to a high-temperature flame for a long period of time Since it is advantageous in thermal durability that is directly related to product lifespan due to its characteristics, it is possible to continuously operate, so that the turbulence generator 31 is designed to have a certain ratio of thickness, which is the most important thing in a combustor to increase efficiency through operation and maintain the product. It can be seen that the reliability is increased.

Hereinafter, a combustion apparatus capable of maximizing the combustor operation efficiency and emission performance according to a second embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present embodiment is different from the first embodiment in that the central portion of the turbulence generating unit 231 is formed to be convex. For the configuration overlapping with the first embodiment in this embodiment, the description of the first embodiment is referred to.

Referring to FIG. 10 , the turbulence generator 231 may be formed to be convex in a direction toward the combustion chamber. That is, when the central portion of the turbulence generating unit 231 is formed to be convex with respect to the direction toward the combustion chamber, the pre-mixer is sprayed to spread in the circumferential direction of the turbulence generating unit 231 to form a wider flame. do. Therefore, the width of the generated flame is wide and a thin flat flame is formed, so there is an advantage in that the generation of pollutants such as carbon monoxide and nitrogen oxide (NOx) can be further minimized. In addition, even if flashback occurs at a low load, the central portion of the flame is extinguished and formed in a donut shape in the flame backfired with a convex structure. Accordingly, the size of the flame becomes smaller and the flames backfired by being dispersed between the small grids have a quenching effect that weakens the intensity of the flame due to an increase in heat loss received from the walls of each grid. (231) has the advantage of reducing the thermal damage.

Hereinafter, a combustion apparatus capable of maximizing the combustor operation efficiency and emission performance according to a third embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present embodiment is different from the first embodiment in that the central portion of the turbulence generating unit 331 is concave. For the configuration overlapping with the first embodiment in this embodiment, the description of the first embodiment is referred to.

Referring to FIG. 11 , the turbulence generating unit 331 may be concavely formed in a direction toward the combustion chamber. That is, when the central portion of the turbulence generator 231 is formed to be concave with respect to the direction toward the combustion chamber, the pre-mixer is sprayed to gather at the central portion of the turbulence generator 231 so that the flame is formed narrower. . Accordingly, there is an advantage that the temperature of the generated flame is formed higher, and thus the thermal efficiency of the combustion device is increased. In addition, as shown in FIG. 11 in the central portion of the turbulence generating unit 331, in the concave type in which the length of the lattice passage in the form of a duct is shortened in the central portion, the pressure loss of the flow flowing to the central portion is small, so As the flow rate becomes faster, when a flashback occurs, the flame is pushed outward in the direction of the wall of the nozzle, so as in the second embodiment, the size of the flame becomes smaller and dispersed between the small grids, so that the backfired flames are separated from the wall Due to the cooling effect receiving heat loss, there is an advantage in that thermal damage to the turbulence generating unit 331 can be reduced.

Hereinafter, a combustion apparatus capable of maximizing the combustor operation efficiency and emission performance according to a fourth embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present embodiment is different from the first embodiment in that the center of the turbulence generating unit 431 is provided at the center of the inner nozzle unit 32 with respect to the longitudinal direction of the inner nozzle unit 32 . there is For the configuration overlapping with the first embodiment in this embodiment, the description of the first embodiment is referred to.

Referring to FIG. 12 , the center of the turbulence generating unit 431 is provided at the center of the inner nozzle unit 32 in the longitudinal direction of the inner nozzle unit 32 . At this time, when the center of the turbulence generating part 431 is located above the inner nozzle part 32 with respect to the longitudinal direction of the inner nozzle part 32, the flow of the premixer is caused by the lattice hole of the fractal. In maximizing turbulence while passing through 31b, through the second flow path 42 of the orbiting nozzle unit 40, which is the outer side of the turbulence generating nozzle unit 30, the turbulence is rotated through the outer nozzle unit 43. The problem that the intensity of turbulence is weakened even before the strong turbulence generated is directly impacted by the flow, and if the flame is attached to the inside of the nozzle due to the flashback phenomenon, it is directly exposed to the flame and damage or damage occurs, so that the thermal efficiency is reduced There is a problem of reduction. Accordingly, the center of the turbulence generating unit 431 is provided at the center of the inner nozzle unit 32 based on the longitudinal direction of the inner nozzle unit 32 . In addition, when the center of the turbulence generating unit 431 is located at the center of the inner nozzle unit 32 with respect to the longitudinal direction of the inner nozzle unit 32 , the first flow path 41 passes through the first flow path 41 . The fuel gas and air introduced into the first mixing chamber 22 follow the tapered guide part 60 in which the outlet area in the longitudinal direction is narrowed in the first mixing chamber 22, the inner nozzle part As it flows into (32), there is an effect that the fuel gas and air are uniformly introduced into the premixed flow up to the central portion where the center of the turbulence generating unit 431 is located.

As such, those skilled in the art to which the present invention pertains will understand that the above-described technical configuration of the present invention may be implemented in other specific forms without changing the technical spirit or essential characteristics of the present invention.

Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the following claims rather than the above detailed description, and the meaning and scope of the claims and their All changes or modifications derived from the concept of equivalents should be construed as being included in the scope of the present invention.

[Explanation of code]

1: Combustion device

10: gas nozzle unit

20: gas fuel distribution unit

21: first through hole

22: first mixing room

23: second through hole

24: 2nd mixing room

30: turbulence generating nozzle unit

31: turbulence generator

32: inner nozzle part

40: slewing nozzle unit

41: 1st Euro

42: 2nd Euro

43: outer nozzle part

50: air nozzle unit

51: air inlet

52: combustion chamber

60: guide

Claims

a gas nozzle for supplying gas fuel;

a gas fuel distribution unit communicating with the gas nozzle unit to form a space and distributing gas fuel;

a first mixing chamber communicating with the gas fuel distribution unit by a first through hole to form a space in which gas fuel is premixed with air;

a second mixing chamber communicating with the gas fuel distribution unit by a second through hole to form a space in which gas fuel is premixed with air;

a turbulence generating nozzle unit provided between the first mixing chamber and the second mixing chamber to turbulence the premixed gas fuel and air premixed in the first mixing chamber; and

and an air nozzle unit; and a turning nozzle unit communicating with the first mixing chamber and the second mixing chamber so that combustion air can be supplied to each of the first and second mixing chambers.

The orbiting nozzle unit,

a first flow passage communicating with the first mixing chamber so that the gas fuel injected through the first through hole is vertically contacted with the swirled air and mixed; and

a second flow path communicating with the second mixing chamber and allowing the gas fuel injected through the second through hole to vertically contact and mix with air having a lower degree of rotation than the first flow path; and

The turbulence generating nozzle unit,

a block-type turbulence generator provided with a plurality of fractal-shaped lattice holes to induce turbulent flow of the gas fuel and air premixed in the first mixing chamber; and

and a cylindrical inner nozzle for allowing the pre-mixture of gas fuel and air that has passed through the turbulence generator to flow into the combustion chamber; and

The turbulence generator,

Combustion capable of maximizing operation efficiency and exhaust performance of the combustor, characterized in that it is formed long in the longitudinal direction of the inner nozzle part to increase the combustion efficiency by enabling continuous combustion by maintaining rigidity even when a flame is attached by a flashback phenomenon Device.
According to claim 1,

The combustion device capable of maximizing the combustion efficiency and discharge performance of the combustor, characterized in that the length of the turbulence generator is formed to be 0.3 to 0.6 times the length of the inner nozzle.
According to claim 1,

The turbulence generator,

Combustion device capable of maximizing combustion efficiency and exhaust performance, characterized in that it is convexly formed based on the direction toward the combustion chamber.
According to claim 1,

The turbulence generator,

Combustion device capable of maximizing combustion efficiency and exhaust performance, characterized in that it is concavely formed based on the direction toward the combustion chamber.
According to claim 1,

The center of the turbulence generator is

Combustion device capable of maximizing combustion efficiency and discharge performance of a combustor, characterized in that it is provided in the central portion of the inner nozzle portion based on the longitudinal direction of the inner nozzle portion.