CN-121854864-B - Ammonia coal mixed combustion device with circumferentially stepless adjustable plasma free radical injection

CN121854864BCN 121854864 BCN121854864 BCN 121854864BCN-121854864-B

Abstract

The invention relates to the technical field of combustion technology and pollutant control, in particular to an ammonia coal mixed combustion device with circumferential stepless adjustable plasma free radical injection. The ammonia-coal mixed combustion burner comprises an ammonia-coal mixed combustion burner body, a plasma free radical generator system and an on-line diagnosis control system, wherein the ammonia-coal mixed combustion burner body comprises a central primary air channel, an annular ammonia channel and a secondary air channel which are concentrically arranged in sequence from inside to outside along the radial direction, the central primary air channel is arranged in a central primary air shell, an annular flame stabilizing body is arranged at the outlet end of the central primary air channel, which is close to a hearth, and a first smoke reflux zone is formed at the downstream of the annular flame stabilizing body. According to the invention, through double-position circumferential rotatable plasma free radical injection, stepless adjustable discharge distance and online closed-loop control of smoke components, high-efficiency stable mixed combustion of ammonia and coal is realized, the ignition performance, burnout rate and working condition adaptability are obviously improved, simultaneously, ammonia escape and NO X emission are effectively reduced, and the intelligent regulation and control and industrial application values are realized.

Inventors

LI HAIYAN
YA HUAQING
SUN WANGPING
CHENG YU
HOU XIAODAN
LI KUN
FENG HANSHENG
Wu Dianwu
LUO GUANGNAN

Assignees

合肥综合性国家科学中心能源研究院(安徽省能源实验室)

Dates

Publication Date: 20260508
Application Date: 20260318

Claims (10)

1. The ammonia coal mixed combustion device with the circumferential stepless adjustable plasma free radical injection is characterized by comprising an ammonia coal mixed combustion burner body (1), a plasma free radical generator system and an online diagnosis control system; The ammonia-coal mixed combustion burner body (1) comprises a central primary air channel (2), an annular ammonia channel (3) and a secondary air channel (4) which are concentrically arranged in sequence from inside to outside along the radial direction, wherein the central primary air channel (2) is arranged in a central primary air shell (114), an annular flame stabilizing body (109) is arranged near the outlet end of a hearth, a first flue gas reflux zone (121) is formed at the downstream of the annular flame stabilizing body (109), the annular ammonia channel (3) is arranged in an annular space between the central primary air shell (114) and an ammonia fuel outer shell (112), an axial ammonia channel (110) is arranged near the outlet end of the ammonia channel, the radial ammonia channel (111) is also arranged on the central primary air shell (114), and a premixing zone (108) is jointly formed at the outlet of the central primary air channel (2), the outlet of the annular ammonia channel (3) and the front of the outlet of the secondary air channel (4); the plasma radical generator system comprises a first position plasma radical generator (5) and a second position plasma radical generator (6); The second position plasma free radical generator (6) is arranged on the annular flame stabilizing body (109) and comprises at least two second position plasma free radical generator units distributed along the circumferential direction; the ammonia fuel gas generator comprises an ammonia fuel gas generator body (112), a first position plasma free radical generator (5), a second position plasma free radical generator (5), a first position plasma free radical generator unit, a second position plasma free radical generator unit and a discharge distance-adjustable plasma free radical generator, wherein the first position plasma free radical generator (5) is arranged on the ammonia fuel gas generator body (112) and comprises at least two first position plasma free radical generator units distributed along the circumferential direction; The online diagnosis control system comprises an online monitoring system and a closed-loop control system, wherein the online monitoring system comprises a shell laser emitting end (801) and a shell laser receiving end (901) which are symmetrically arranged at the outlet end of the secondary air channel (4), a light path formed by the shell laser emitting end (801) and the shell laser receiving end (901) covers the diameter of the section of the outlet of the burner and is used for detecting the concentration of NO X and the concentration of NH 3 in smoke in real time online, and the closed-loop control system is used for adjusting the discharge distance of the discharge distance-adjustable plasma free radical generator and/or the rotating speed of the second driving motor unit (116) and/or the ammonia flow of the annular ammonia channel (3) in real time according to detected concentration signals of NO X and NH 3 .
2. The ammonia coal mixed combustion device with circumferential stepless adjustable plasma free radical injection according to claim 1, wherein the axial ammonia channel (110) comprises an axial ammonia and plasma free radical first injection channel (1101), an axial ammonia and plasma free radical second injection channel (1102) and an axial ammonia and plasma free radical third injection channel (1103) which are sequentially arranged along the axial direction of an ammonia fuel outer shell (112) and are used for injecting ammonia and plasma free radicals into the central primary air channel (2).
3. The ammonia coal mixed combustion device with the circumferential stepless adjustable plasma free radical injection as claimed in claim 2, wherein the axial ammonia and the plasma free radical injection channels are all round holes and distributed along a circumferential annular array, the distribution angle of two adjacent channels is 7.5-15 degrees, and the included angle between the axial ammonia and the plasma free radical injection channels and the radial axis is 15-30 degrees, so as to form a clockwise injection stream.
4. The circumferentially stepless adjustable plasma radical injection ammonia coal mixed combustion device according to claim 1, wherein the radial side ammonia channel (111) comprises radial side ammonia and plasma radical first injection channels (1111), radial side ammonia and plasma radical second injection channels (1112) and radial side ammonia and plasma radical third injection channels (1113) which are circumferentially arranged at intervals along a central primary air shell (114) and are used for injecting ammonia and plasma radicals into the premixing zone (108).
5. The ammonia coal mixed combustion device with the circumferential stepless adjustable plasma free radical injection according to claim 4, wherein the radial side ammonia and plasma free radical first injection channels (1111) are rectangular channels, are distributed in a circumferential clockwise annular array, have a distribution angle of 15 degrees, and have an included angle of 15 degrees with a radial axis; The radial side ammonia and plasma free radical second injection channel (1112) and the radial side ammonia and plasma free radical third injection channel (1113) are both arranged as round hole channels, distributed along a circumferential annular array, and the distribution angles of two adjacent channels are 7.5-15 degrees, and the included angle between the two adjacent channels and the radial axis is 15-30 degrees, so that a rotary stream taking the central primary air channel (2) as the center of a circle is formed.
6. The ammonia coal co-fired combustion device with circumferentially stepless adjustable plasma radical injection according to claim 1, wherein the first position plasma radical generator (5) comprises a first position 90 ° plasma radical generator (501), a first position 210 ° plasma radical generator (502), a first position 330 ° plasma radical generator (503), the first position 90 ° plasma radical generator (501), the first position 210 ° plasma radical generator (502) and the first position 330 ° plasma radical generator (503) are circumferentially arranged at 120 ° counterclockwise intervals along the ammonia fuel outer shell (112) for injecting plasma radicals into the first flue gas recirculation zone (121) and the central fuel stream.
7. The ammonia coal mixed combustion device with circumferential stepless adjustable plasma free radical injection according to claim 1, wherein the second position plasma free radical generator (6) comprises a second position 30 DEG plasma free radical generator (601), a second position 150 DEG plasma free radical generator (602), a second position 270 DEG plasma free radical generator (603), the second position 30 DEG plasma free radical generator (601), the second position 150 DEG plasma free radical generator (602) and the second position 270 DEG plasma free radical generator (603) are arranged at intervals of 120 DEG anticlockwise along the circumference of the annular flame stabilizing body (109) for injecting plasma free radicals into the premixing zone (108) and the flame zone.
8. The ammonia coal mixed combustion device with the circumferential stepless adjustable plasma free radical injection according to claim 1, wherein the first position plasma free radical generator (5) further comprises a discharge distance adjustable plasma free radical generator unit, wherein the discharge distance adjustable plasma free radical generator unit comprises a generator shell (504), a high-voltage electrode (507), a ground electrode (508), a high-temperature resistant ceramic nozzle (509) and an electrode distance adjusting mechanism; the generator shell (504) is detachably arranged on the ammonia fuel shell body (112) or the annular flame stabilizing body (109); The high-voltage electrode (507) and the ground electrode (508) are coaxially arranged in the generator shell (504), and an annular discharge gap and a plasma free radical channel (516) are formed between the high-voltage electrode and the ground electrode; an insulating sleeve (505) and a swirl vane (506) are sleeved outside the high-voltage electrode (507); the high-temperature resistant ceramic nozzle (509) is arranged at the front end of the generator shell (504) and is connected with the ground electrode (508).
9. The circumferentially stepless adjustable plasma radical injection ammonia coal mixed combustion device according to claim 8, wherein the electrode distance adjusting mechanism comprises a first driving motor group (512), a pinion shaft (514) and a movable gear (515); The first driving motor unit (512) is fixed on the generator shell (504), the output end of the first driving motor unit is connected with the pinion shaft (514), the movable gear (515) is connected with the generator shell (504) through a screw rod and meshed with the pinion shaft (514), and the first driving motor unit (512) drives the pinion shaft (514) to drive the movable gear (515) to rotate so as to drive the generator shell (504) to axially move along with the ground electrode (508) to realize real-time continuous adjustment of the discharge distance between the high-voltage electrode (507) and the ground electrode (508).
10. The circumferentially stepless adjustable plasma radical injection ammonia coal co-combustion device according to claim 1, wherein the working flow of the device comprises the following steps: step one, respectively introducing a primary air pulverized coal mixture, ammonia and secondary air into a central primary air channel (2), an annular ammonia channel (3) and a secondary air channel (4); Step two, starting the first position plasma free radical generator (5), starting the second driving motor group (116), driving the ammonia fuel shell (112) and the first position plasma free radical generator (5) to rotate at a rotating speed of 1-10 rpm, and injecting plasma free radicals into the first flue gas recirculation zone (121) and the central fuel flow to assist ignition of initial ammonia fuel; step three, starting a second position plasma free radical generator (6), injecting plasma free radicals into the premixing zone (108) and the flame zone, and strengthening mixed combustion; Step four, detecting the concentration of NO X and the concentration of NH 3 in the flue gas at the outlet of the burner on line in real time through a shell laser transmitting end (801) and a shell laser receiving end (901); And fifthly, according to the detected NO X and NH 3 concentrations, performing at least one adjustment operation by a closed loop control system, namely increasing the discharge distance of the plasma free radical generator unit and/or increasing the rotation speed when the NO X concentration is higher than a first set threshold value, and reducing the discharge distance of the plasma free radical generator and/or adjusting the ammonia flow when the NH 3 concentration is higher than a second set threshold value.

Description

Ammonia coal mixed combustion device with circumferentially stepless adjustable plasma free radical injection Technical Field The invention relates to the technical field of combustion technology and pollutant control, in particular to an ammonia coal mixed combustion device with circumferential stepless adjustable plasma free radical injection. Background Ammonia gas is used as a zero-carbon fuel to be mixed with pulverized coal for combustion, and is an important technical approach for realizing low-carbon transformation and reducing carbon emission of facilities such as a coal-fired boiler, an industrial kiln and the like. However, the ammonia gas has high ignition temperature, slow flame propagation speed and high mixing difficulty with solid fuels such as coal powder, and the problems of ignition difficulty, poor combustion stability, low combustion efficiency, high emission of nitrogen oxides (NO X) and the like easily occur when the ammonia gas is directly mixed and burned. The traditional burner structure only depends on flow field tissue fuel mixing, and is difficult to realize ammonia gas activation, gas-solid two-phase efficient mixing, flame stable combustion and combustion pollutant cooperative control at the same time, and cannot meet the actual requirements of industrial low-nitrogen, stable and efficient combustion. At present, the prior art tries to adopt plasma to assist and strengthen ammonia coal mixed combustion, but the defects of single plasma injection mode, uneven circumferential distribution, simple regulation and control means and the like generally exist, the uniform global distribution of plasma free radicals and the accurate regulation of excitation intensity are difficult to realize in the combustor, meanwhile, the on-line monitoring and closed-loop regulation and control of smoke components at a combustion outlet are lacking, the plasma parameters, the ammonia coal ratio and the rotation mixing intensity cannot be adaptively optimized according to the real-time combustion state, so that the stability, the combustion efficiency and the low emission performance of the ammonia coal mixed combustion still have obvious bottlenecks, and the industrialized application and popularization of the plasma assisted ammonia coal mixed combustion technology are limited. Therefore, the application provides an ammonia coal mixed combustion device with circumferential stepless adjustable plasma free radical injection. Disclosure of Invention The invention aims to solve the problems of difficult ignition of ammonia, uneven mixing, poor combustion stability, higher NO X emission, single plasma auxiliary mode, inflexible regulation, lack of on-line closed-loop control and the like in the background technology, and provides a circumferential stepless adjustable ammonia coal mixed combustion device with plasma free radical injection. The technical scheme of the invention is that the ammonia coal mixed combustion device with circumferential stepless adjustable plasma free radical injection comprises an ammonia coal mixed combustion burner body, a plasma free radical generator system and an online diagnosis control system; The ammonia-coal mixed combustion burner body comprises a central primary air channel, an annular ammonia channel and a secondary air channel which are concentrically arranged in sequence from inside to outside along the radial direction, wherein the central primary air channel is arranged in a central primary air shell, an annular flame stabilizing body is arranged at the outlet end of the central primary air channel, which is close to a hearth, and a first smoke reflux zone is formed at the downstream of the annular flame stabilizing body; The plasma radical generator system comprises a first position plasma radical generator and a second position plasma radical generator; The second position plasma free radical generator is arranged on the annular flame stabilizing body and comprises at least two second position plasma free radical generator units distributed along the circumferential direction; the ammonia fuel shell is provided with a large gear which is meshed with a gear shaft driven by a second driving motor group so as to drive the ammonia fuel shell and the first position plasma free radical generator to generate circumferential rotation, wherein the first position plasma free radical generator and/or the second position plasma free radical generator are/is discharge distance adjustable plasma free radical generators; The online diagnosis control system comprises an online monitoring system and a closed-loop control system, wherein the online monitoring system comprises a shell laser transmitting end and a shell laser receiving end which are symmetrically arranged at the outlet end of the secondary air channel, a light path formed by the shell laser transmitting end and the shell laser receiving end covers the section diameter of the outlet of the burner and is used for d