CN-121977210-A - Porous pure hydrogen combustion nozzle

CN121977210ACN 121977210 ACN121977210 ACN 121977210ACN-121977210-A

Abstract

The invention relates to the technical field of combustion and energy utilization, in particular to a porous pure hydrogen combustion spray head, wherein a stable backflow anchoring area is formed around a spray nozzle through the cooperative combination of a cylindrical counter bore structure of a hydrogen spray hole and a hydrogen spray nozzle boss, the backfire preventing capability is effectively improved, a wide stable combustion area is realized by keeping flame stability under different load conditions through the cooperative action of coaxial graded air supply and an outer cyclone backflow structure, the combustion area forms temperature and concentration gradient under the effect of layered air supply and surrounding air curtain cladding, the peak temperature of the flame is obviously reduced, NO x emission is reduced, a cooling barrier formed by surrounding cyclone air effectively isolates thermal shock of high-temperature gas to the surface of the spray head, the service life of the spray head is prolonged, and the cooperation of a cyclone air field and the coaxial air supply structure reduces the coupling of combustion and acoustic modes, improves the acoustic stability of a combustion system and reduces combustion oscillation and noise.

Inventors

TANG ZHIHUA
GUO HUAFANG
YANG CAIYUN
YIN HUA
LI JIAJIE

Assignees

中国科学院广州能源研究所

Dates

Publication Date: 20260505
Application Date: 20260209

Claims (8)

1. A porous pure hydrogen combustion nozzle, comprising: The bottom plate comprises a bottom plate main body, wherein the upper end surface and the lower end surface of the bottom plate main body correspondingly form a combustion zone and a gas supply zone, and the combustion zone and the gas supply zone are separated by the bottom plate main body; A hydrogen nozzle boss provided on an upper end surface of the base plate main body; A plurality of hydrogen injection holes for providing hydrogen are uniformly distributed along the axis of the central axis of the hydrogen nozzle boss, and the injection direction of each hydrogen injection hole is consistent with the direction of the central axis of the hydrogen nozzle boss; A plurality of micro hydrogen mixing air holes are radially and uniformly distributed on the outer wall of the boss of the hydrogen nozzle; The bottom plate main body is provided with a plurality of centripetal oxygen supply air holes penetrating through the upper end face and the lower end face, the injection directions of the centripetal oxygen supply air holes point to the central axis of the hydrogen nozzle boss, and the centripetal oxygen supply air holes are circumferentially arranged along the outer side of the hydrogen nozzle boss; The upper end face of the bottom plate main body is provided with a plurality of outer side rotational flow air holes, a plurality of outer side rotational flow air holes are formed along the circumferential direction of the outer side of the bottom plate main body, and a plurality of outer side rotational flow air holes are formed in the outer side of the centripetal oxygen supply air holes.
2. The porous pure hydrogen combustion nozzle of claim 1, wherein each of said hydrogen injection holes comprises a nozzle and a cylindrical counterbore structure surrounding said nozzle, said cylindrical counterbore structure forming a recirculation anchor zone and a localized low velocity vortex zone around said nozzle and cooperating with air surrounding said hydrogen injection holes to form an annular cooling gas flow zone.
3. The porous pure hydrogen combustion nozzle according to claim 1, wherein a plurality of igniter holes for mounting an igniter are further provided on the base plate body along the circumferential direction of the hydrogen nozzle boss; the level of a plurality of little hydrogen holes that mixes is less than the horizontal position of ignition's play burner port, just the some firearm holes with little hydrogen holes are adjacent to be arranged, when spraying, the hydrogen in little hydrogen gas hole with encircle the hydrogen nozzle boss mixes and forms primary dilution gas mixture.
4. The porous pure hydrogen combustion nozzle according to claim 1, wherein the gas supply end and the combustion end of the centripetal oxygen supply air hole are respectively arranged in the gas supply area and the combustion area, and the centripetal oxygen supply air hole penetrates through the upper end face and the lower end face of the bottom plate main body; The centripetal oxygen supply air hole comprises a perforation and a conical counter bore structure surrounding the perforation, and the setting direction of the conical counter bore structure points to the central axis position of the hydrogen nozzle boss, so that air jet flow in the outer side rotational flow air hole forms a rotational flow air field when entering the combustion zone.
5. The porous pure hydrogen combustion nozzle according to claim 1, wherein the air supply end and the combustion end of the outside swirling air hole are correspondingly arranged in the air supply area and the combustion area, the outside swirling air hole penetrates through the upper end face and the lower end face of the bottom plate main body, the air supply end and the combustion end are arranged on the same circumference, the centripetal oxygen supply air hole forms a certain included angle with the lower end face of the bottom plate main body, so that air emitted by the centripetal oxygen supply air hole forms centripetal jet flow, and an oxygen-enriched coating layer is formed around the hydrogen jet flow.
6. The porous pure hydrogen combustion nozzle according to claim 1, wherein the porous pure hydrogen combustion nozzle adopts a multi-stage nozzle external mixing mode, and a coaxial graded air supply structure is formed by using the distribution of the micro-mixing hydrogen air holes, the centripetal oxygen supply air holes and the external rotational flow air holes.
7. The porous pure hydrogen combustion burner cap of claim 6, wherein the coaxial staged gas supply structure includes a first mixing zone, a second mixing zone, and a third mixing zone; The third mixing region is arranged outside the first mixing region and the second mixing region, the first mixing region is outside the outer wall of the hydrogen nozzle boss, and the second mixing region is at the upper part of the hydrogen nozzle boss; In the first mixing zone, the micro-hydrogen mixing air holes and the centripetal oxygen supply air holes act in pairs to form primary diluted mixed gas; In the second mixing zone, the hydrogen jet injected by the hydrogen injection hole is further mixed with the primary diluted mixed gas at the outer edge of the hydrogen nozzle boss to form a high-temperature combustion core, and combustion products are generated after combustion; In the third mixing zone, the air jet in the outer swirling air holes is further mixed and diluted with the combustion products to form a stable cladding flow and a temperature gradient.
8. The porous pure hydrogen combustion nozzle of claim 1, wherein the hydrogen nozzle boss is of cylindrical configuration and an upper edge of the hydrogen nozzle boss is provided with an annular chamfer to improve fluid transition and reduce localized overheating of the edge.

Description

Porous pure hydrogen combustion nozzle Technical Field The invention relates to the technical field of combustion and energy utilization, in particular to a porous pure hydrogen combustion nozzle. Background With the increasing demands for the transformation and carbon reduction of global energy structures, hydrogen energy is considered to be an important component of future clean energy systems due to its renewable, carbon-free emission characteristics. The combustion product of the hydrogen is only water vapor, does not contain carbon dioxide, can effectively replace fossil fuel, and reduces the emission of greenhouse gases. However, the hydrogen has obvious differences with the traditional hydrocarbon fuel in combustion characteristics, and has high diffusivity, wide combustion limit range, low ignition energy and higher combustion speed, so that phenomena such as tempering, fire removal, deflagration and uneven temperature field are easy to occur in the pure combustion process, and great challenges are brought to the design of a nozzle structure and the control of combustion stability. Currently, the nozzle designs for hydrogen combustion are mainly of the following types: 1. The premixed combustion nozzle can achieve uniform combustion by fully mixing fuel and air before combustion, but has high combustion speed and high diffusion performance, is easy to generate tempering problem in the nozzle and has poor safety; 2. The nozzle structure combining partial premixing and diffusion improves combustion stability to a certain extent, but still has the problems of low combustion efficiency and large nitrogen oxide (NO x) generation caused by a local high-temperature region. 3. The swirl nozzle forms a central backflow area by introducing swirl to stabilize flame, but the conventional swirl structure still faces the problems of uneven mixing, flame falling off and large combustion noise when being used for pure hydrogen combustion. Therefore, there is a need for a pure hydrogen combustion nozzle with simple structure, uniform mixing, stable combustion and good anti-backfire capability, so as to improve the safety and the thermal efficiency of the hydrogen combustion device and reduce the emission of NO x. Disclosure of Invention The invention aims to solve the problems in the prior art and provides a porous pure hydrogen combustion nozzle. In order to solve the problems existing in the prior art, the invention adopts the following technical scheme: A porous pure hydrogen combustion showerhead comprising: The bottom plate comprises a bottom plate main body, wherein the upper end surface and the lower end surface of the bottom plate main body correspondingly form a combustion zone and a gas supply zone, and the combustion zone and the gas supply zone are separated by the bottom plate main body; A hydrogen nozzle boss provided on an upper end surface of the base plate main body; A plurality of hydrogen injection holes for providing hydrogen are uniformly distributed along the axis of the central axis of the hydrogen nozzle boss, and the injection direction of each hydrogen injection hole is consistent with the direction of the central axis of the hydrogen nozzle boss; A plurality of micro hydrogen mixing air holes are radially and uniformly distributed on the outer wall of the boss of the hydrogen nozzle; The bottom plate main body is provided with a plurality of centripetal oxygen supply air holes penetrating through the upper end face and the lower end face, the injection directions of the centripetal oxygen supply air holes point to the central axis of the hydrogen nozzle boss, and the centripetal oxygen supply air holes are circumferentially arranged along the outer side of the hydrogen nozzle boss; The upper end face of the bottom plate main body is provided with a plurality of outer side rotational flow air holes, a plurality of outer side rotational flow air holes are formed along the circumferential direction of the outer side of the bottom plate main body, and a plurality of outer side rotational flow air holes are formed in the outer side of the centripetal oxygen supply air holes. As an improvement of the technical scheme of the porous pure hydrogen combustion nozzle, each hydrogen jet hole comprises a nozzle and a cylindrical counter bore structure surrounding the nozzle, wherein the cylindrical counter bore structure forms a reflux anchoring area and a local low-speed vortex area around the nozzle and is matched with air around the hydrogen jet hole to form an annular cooling airflow area. As an improvement of the technical scheme of the porous pure hydrogen combustion nozzle, a plurality of igniter holes for installing an ignition device are also formed in the bottom plate main body along the circumferential direction of the hydrogen nozzle boss; the level of a plurality of little hydrogen holes that mixes is less than the horizontal position of ignition's play burner port, just the some firearm h