阅读说明：本技术 一种多喷嘴粉浆气化炉粉煤烧嘴投料方法 (Feeding method for pulverized coal burner of multi-nozzle slurry gasification furnace ) 是由 付伟贤 于 2019-11-06 设计创作，主要内容包括：本发明公开一种多喷嘴粉浆气化炉粉煤烧嘴投料方法,包括：在气化炉粉煤烧嘴通入保护气,所述气化炉是以水煤浆模式运行的；在初始压力下建立粉煤循环,且所述粉煤循环是通过多次减压建立的；待所述粉煤循环稳定后,将粉煤和氧化剂通过进料管线投入所述气化炉。防止粉煤循环由于一次减压,压力差过大导致降温的温差过大,从而使水析出,致使堵塞循环管道,粉煤在线投料失败问题的发生。实现粉煤烧嘴6.5MPa下的高压在线连投,保证了粉煤投料的正常稳定进行,减少了粉煤投料失败及停车事故的发生,从而提高了气化效率。(The invention discloses a pulverized coal burner feeding method of a multi-nozzle slurry gasification furnace, which comprises the following steps: introducing protective gas into a pulverized coal burner of a gasification furnace, wherein the gasification furnace operates in a coal water slurry mode; establishing a pulverized coal cycle at an initial pressure, and the pulverized coal cycle is established by multiple depressurization; and after the pulverized coal is circularly stabilized, feeding the pulverized coal and an oxidant into the gasification furnace through a feeding pipeline. Prevent that fine coal from circulating because once decompression, the too big difference in pressure leads to the too big difference in temperature of cooling to make water appear, cause to block up the circulating line, the emergence of the online material failure problem of throwing of fine coal. The high-pressure online continuous feeding of the pulverized coal burner under 6.5MPa is realized, the normal and stable feeding of the pulverized coal is ensured, the failure of the pulverized coal feeding and the occurrence of parking accidents are reduced, and the gasification efficiency is improved.)

1. A pulverized coal burner feeding method of a multi-nozzle slurry gasification furnace is characterized by comprising the following steps:

introducing protective gas into a pulverized coal burner of a gasification furnace, wherein the gasification furnace operates in a coal water slurry mode;

establishing a pulverized coal cycle at an initial pressure, and the pulverized coal cycle is established by multiple depressurization;

and after the pulverized coal is circularly stabilized, feeding the pulverized coal and an oxidant into the gasification furnace through a feeding pipeline.

2. The charging method according to claim 1, characterized in that the operating pressure P of the gasifier in the coal-water slurry mode, the initial pressure P1 of the pulverized coal circulation, the preset pressure P2 of the oxidizer;

p, P1 and P2 satisfy: p1> P2> P.

3. The charging method according to claim 2, characterized in that the operating pressure P of the gasifier in the coal-water slurry mode, the initial pressure P1 of the pulverized coal circulation, the preset pressure P2 of the oxidizer;

p, P1, P2 also satisfies: P1-P is more than or equal to 0.2MPa and less than or equal to 1.0MPa, and P2-P is more than or equal to 0.1MPa and less than or equal to 0.5 MPa.

4. The charging method according to claim 2, characterized in that the pulverized coal is circulated through two depressurization steps;

the initial pressure P1 of the pulverized coal circulation is more than or equal to 6.5 MPa; reducing the pressure to 2/3P1-1/2P1 for the first time; and reducing the pressure for the second time to the normal pressure.

5. The charging method according to claim 1, characterized in that the pulverized coal is conveyed into the gasification furnace by a guide gas;

the pressure P3 of the flow-guiding gas satisfies: p < P3 < P1.

6. The charging method according to claim 5, characterized in that the diversion gas is carbon dioxide gas;

the initial temperature T1 of the carbon dioxide gas satisfies: t1 is more than or equal to 120 ℃ and less than or equal to 150 ℃.

7. The charging method according to any one of claims 1 to 6, wherein the charging ratio of the oxidizing agent to the pulverized coal is 0.45 to 0.60Nm 3/kg.

8. The method of any one of claims 1 to 6, wherein the feeding of the oxidant comprises:

dividing a preset oxidant amount from the oxidant, and introducing the oxidant into a top pulverized coal burner of the gasification furnace;

equally dividing the residual oxidant according to the number of the coal slurry burners of the gasification furnace;

and introducing each part of the equally divided oxidant into one coal slurry burner.

9. The charging method according to any one of claims 8, wherein the predetermined amount of the oxidant accounts for 50 to 90% of the total amount of the oxidant.

10. The charging method according to any one of claims 1 to 6, wherein the oxidizing agent is oxygen.

Technical Field

The invention belongs to the technical field of new energy, and particularly relates to a pulverized coal burner feeding method of a multi-nozzle slurry gasification furnace.

Background

The essence of the powder slurry gasification technology is that the slurry carbon-containing organic matter and the powder carbon-containing organic matter are sprayed into the gasification furnace simultaneously, so that the water entrainment is reduced, the concentration of the whole carbon-containing organic matter is indirectly improved, and the high-efficiency co-gasification of the slurry carbon-containing organic matter and the powder carbon-containing organic matter is realized.

The slurry powder gasification furnace is divided into a top single-nozzle structure and a multi-nozzle structure (4 slurry burners are arranged on a furnace body in an opposite mode, and 1 pulverized coal burner is arranged on the top), the gasification pressure of the slurry powder gasification furnace is generally about 6.5MPa, the mode of gradually increasing the pressure after feeding under low pressure is generally adopted in the process of starting, and the prior multi-nozzle gasification furnace realizes the continuous feeding under pressure of the slurry coal burner under 6.5 MPa. At present, the pressurized feeding of a pulverized coal burner under 6.5MPa is not realized, mainly due to the limitation of a pressure reducing device in the pulverized coal circulation process, the high-pressure circulation of the pulverized coal under 6.5MPa is firstly established when the pulverized coal is subjected to high-pressure online feeding, however, CO2 is generally adopted as drainage gas and conveying gas in the circulation process, the temperature drop of high-pressure CO2 gas after the pressure reducing device is large, the precipitation of water in the pulverized coal can be caused by the excessively low temperature of the pulverized coal when the pulverized coal passes through the pressure reducing device, a circulation pipeline is blocked, and the failure of the pulverized coal online feeding or even the integral.

Therefore, on the premise of maintaining the normal feeding of the coal slurry burner without influencing the normal operation of the system, how to realize the high-pressure online continuous casting of the pulverized coal burner under 6.5MPa is very important for the gasification furnace to reach the normal operation state of the pulverized coal slurry.

Disclosure of Invention

Objects of the invention

The invention aims to provide a pulverized coal burner feeding method of a multi-nozzle slurry gasifier to solve the problem that online feeding of pulverized coal fails due to the fact that water in the pulverized coal is separated out and a circulating pipeline is blocked.

(II) technical scheme

In order to solve the above problems, a first aspect of the present invention provides a pulverized coal burner feeding method for a multi-nozzle slurry gasification furnace, including: introducing protective gas into a pulverized coal burner of a gasification furnace, wherein the gasification furnace operates in a coal water slurry mode; establishing a pulverized coal cycle at an initial pressure, and the pulverized coal cycle is established by multiple depressurization; and after the pulverized coal is circularly stabilized, feeding the pulverized coal and an oxidant into the gasification furnace through a feeding pipeline.

Further, the coal water slurry mode operation pressure P of the gasification furnace, the initial pressure P1 of the pulverized coal circulation and the preset pressure P2 of the oxidant are controlled by the control system; p, P1 and P2 satisfy: p1> P2> P.

Further, the coal water slurry mode operation pressure P of the gasification furnace, the initial pressure P1 of the pulverized coal circulation and the preset pressure P2 of the oxidant are controlled by the control system; p, P1, P2 also satisfies: P1-P is more than or equal to 0.2MPa and less than or equal to 1.0MPa, and P2-P is more than or equal to 0.1MPa and less than or equal to 0.5 MPa.

Further, the pulverized coal is circularly decompressed twice; wherein the initial pressure P1 of the pulverized coal is more than or equal to 6.5 MPa; reducing the pressure to 2/3P1-1/2P1 for the first time; and reducing the pressure for the second time to the normal pressure.

Further, the pulverized coal is conveyed into the gasification furnace by a flow guiding gas; the pressure P3 of the flow-guiding gas satisfies: p < P3 < P1.

Further, the drainage gas is carbon dioxide gas; the initial temperature T1 of the carbon dioxide gas satisfies: t1 is more than or equal to 120 ℃ and less than or equal to 150 ℃.

Further, the feeding proportion of the oxidant and the pulverized coal is 0.45-0.60Nm 3/kg.

Further, the feeding of the oxidant comprises: dividing a preset oxidant amount from the oxidant, and introducing the oxidant into a top pulverized coal burner of the gasification furnace; equally dividing the residual oxidant according to the number of the coal slurry burners of the gasification furnace; and introducing each part of the equally divided oxidant into one coal slurry burner.

Further, the preset oxidant accounts for 50-90% of the total oxidant.

Further, the oxidant is oxygen.

The invention aims to provide a pulverized coal burner feeding method of a multi-nozzle slurry gasification furnace, which comprises the following steps: introducing protective gas into a pulverized coal burner of a gasification furnace, wherein the gasification furnace operates in a coal water slurry mode; establishing a pulverized coal cycle at an initial pressure, and the pulverized coal cycle is established by multiple depressurization; and after the pulverized coal is circularly stabilized, feeding the pulverized coal and an oxidant into the gasification furnace through a feeding pipeline. Prevent that fine coal from circulating because once decompression, the too big difference in pressure leads to the too big difference in temperature of cooling to make water appear, cause to block up the circulating line, the emergence of the online material failure problem of throwing of fine coal.

(III) advantageous effects

The technical scheme of the invention has the following beneficial technical effects:

the high-pressure online continuous feeding of the pulverized coal burner under 6.5MPa is realized, the normal and stable feeding of the pulverized coal is ensured, the failure of the pulverized coal feeding and the occurrence of parking accidents are reduced, and the gasification efficiency is improved.

Drawings

FIG. 1 is a flow diagram of a charging method according to a first embodiment of the present invention;

FIG. 2 is a flow diagram of a pulverized coal feed according to an embodiment of the present invention;

FIG. 3 is a flow diagram of a pulverized coal oxidant feed in accordance with an embodiment of the present invention.

Reference numerals:

1: a gasification furnace; 101: a coal slurry burner group; 102: a coal slurry burner group; 103: a pulverized coal burner; 201: an oxygen shut-off valve; 202: a flow regulating valve; 203: a front cut-off valve; 204: a rear cut-off valve; 205: an oxygen flow distributor; 206: an emptying cut-off valve; 207: a pressure regulating valve; 208: a restriction orifice plate; 209: a shielding gas shutoff valve; 210: an oxygen-coal ratio regulator; 211: a shut-off valve; 212: a shut-off valve; 213: a shut-off valve; 214: a shut-off valve; 301: a pulverized coal low-pressure storage tank; 302: an inflator; 303: locking a bucket for the pulverized coal; 304: a pulverized coal high-pressure storage tank; 305: a feeder; 306: a gas heater; 307: a shut-off valve; 308: a shut-off valve; 309: a shut-off valve; 310: a shut-off valve; 311: a shut-off valve; 312: adjusting an angle valve; 313: a three-way valve; 314: a circulation cut-off valve; 315: a pressure reducing device; 316: a pressure reducing device; 317: a shut-off valve; 318: a shielding gas shutoff valve; 319: a drainage gas shutoff valve; 320: a pressure regulating valve; PT 1: a pressure transmission control device; PT 2: a pressure measuring device; PDIC 2: a differential pressure transmission control device; ST 1: a speed measuring device; DT 1: a density measuring device; FIY 1: a pulverized coal flow rate calculation device; SIC 1: a pulverized coal speed transmission control device; FT 1: a flow transmission control device; FT 2: a transport gas flow measuring device; FIC 1: a pulverized coal flow and transmission control device; FIC 2: a conveying airflow quantity and conveying control device.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.

As shown in fig. 1, in a first aspect of an embodiment of the present invention, there is provided a method for feeding pulverized coal burners of a multi-nozzle slurry gasifier, including:

s1: introducing protective gas into a pulverized coal burner of a gasification furnace, wherein the gasification furnace operates in a coal water slurry mode;

s2: establishing a pulverized coal circulation at an initial pressure, and the pulverized coal circulation is established by multiple depressurization;

s3: after the pulverized coal is circularly stabilized, the pulverized coal and an oxidant are put into the gasification furnace through a feeding pipeline.

The method prevents the problems that the temperature difference of temperature reduction is too large due to the fact that the pressure difference is too large during the pulverized coal circulation is reduced once, so that water is separated out, a circulation pipeline is blocked, and the pulverized coal on-line feeding fails. The high-pressure online continuous feeding of the pulverized coal burner under 6.5MPa is realized, the normal and stable feeding of the pulverized coal is ensured, the failure of the pulverized coal feeding and the occurrence of parking accidents are reduced, and the gasification efficiency is improved.

Optionally, the coal-water slurry mode operation pressure P of the gasification furnace, the initial pressure P1 of the pulverized coal circulation, and the preset pressure P2 of the oxidant; p, P1 and P2 satisfy: p1> P2> P. Optionally, the coal-water slurry mode operation pressure P of the gasification furnace, the initial pressure P1 of the pulverized coal circulation, and the preset pressure P2 of the oxidant; p, P1, P2 also satisfies: P1-P is more than or equal to 0.2MPa and less than or equal to 1.0MPa, and P2-P is more than or equal to 0.1MPa and less than or equal to 0.5 MPa.

The pulverized coal feeding can be normally and stably carried out by feeding under the pressure condition, so that the operation stability of the gasification furnace is ensured, and further the occurrence of parking accidents is avoided.

Optionally, the pulverized coal is circularly decompressed twice; wherein the initial pressure P1 of the pulverized coal is more than or equal to 6.5 MPa; reducing the pressure to 2/3P1-1/2P1 for the first time; and reducing the pressure for the second time to the normal pressure.

Above-mentioned embodiment has solved because high pressure throws the material through the decompression of minimum number of times, once reduces the too big problem that leads to water to appear of temperature difference, has guaranteed that circulation pipeline's operation is usually, has saved the consumptive material of decompression equipment and pipeline simultaneously.

Optionally, the pulverized coal is conveyed to the gasification furnace by a flow guiding gas; the pressure P3 of the flow-guiding gas satisfies: p < P3 < P1. Optionally, the diversion gas is carbon dioxide gas; the initial temperature T1 of the carbon dioxide gas satisfies: t1 is more than or equal to 120 ℃ and less than or equal to 150 ℃.

Carbon dioxide is used as the induced flow gas to convey the pulverized coal under the conditions, so that the cost is lowest, the pulverized coal is effectively prevented from being oxidized, and the purpose of conveying the pulverized coal can be well achieved.

Optionally, the feeding ratio of the oxidant to the pulverized coal is 0.45-0.60Nm 3/kg.

Optionally, the feeding of the oxidant comprises: dividing the oxidant into preset oxidant amount and introducing the preset oxidant amount into a top pulverized coal burner of a gasification furnace; equally dividing the residual oxidant according to the number of the coal slurry burners of the gasification furnace; and introducing each part of the evenly divided oxidant into a coal slurry burner.

In the existing feeding mode, after an oxidant enters a gasification furnace through a top pulverized coal burner, because the top space is small and oxygen is relatively sufficient, upward synthesis gas generated by coal slurry burner impact can generate a homogeneous combustion reaction before a gasification reaction of pulverized coal and oxygen, a large amount of heat is released to cause the top of the gasification furnace to be over-temperature, and pulverized coal feeding failure or even the whole gasification furnace is stopped; feeding an oxidant by the method of the embodiment, and introducing the oxidant into a top pulverized coal burner of the gasification furnace by dividing the preset oxidant amount; equally dividing the residual oxidant according to the number of the coal slurry burners of the gasification furnace; each part of the evenly-divided oxidant is introduced into one coal slurry burner, so that upward synthetic gas generated by coal slurry burner impact can be effectively prevented from generating homogeneous combustion reaction before gasification reaction of pulverized coal and oxygen, and further, the occurrence of pulverized coal feeding failure and even gasification furnace integral parking accidents is reduced.

Optionally, the preset oxidant amount accounts for 50-90% of the total oxidant amount.

Optionally, the oxidant is oxygen.

As shown in fig. 2 to 3, in a specific embodiment, a method for feeding a pulverized coal burner of a multi-nozzle slurry-powder gasification furnace is provided, which includes:

(1) ensuring that the operating pressure P of the gasification furnace is within a normal range in a water-coal-slurry mode, and introducing protective gas to the top pulverized coal burner 103; keeping a shielding gas cut-off valve 318 and a shielding gas cut-off valve 209 of the pulverized coal pipeline and the pulverized coal oxygen pipeline in an open state, and enabling shielding gas to enter the pulverized coal burner to protect the pulverized coal burner;

(2) the on-line feeding flow of the pulverized coal and the oxidant is established through the pulverized coal circulation loop and the oxidant emptying pipeline.

The process of establishing the pulverized coal circulation is as shown in FIG. 2:

and (3) opening a drainage gas cut-off valve 319, introducing drainage gas into the low-pressure storage tank 301 through a pressure reducing device 315 and a pressure reducing device 316, and regulating the pressure of the drainage gas through a pressure regulating valve 320, wherein the pressure of the drainage gas is P3, and P is more than P3 and more than P1. The pressure of the drainage gas is less than that of the pulverized coal circulating pipeline and greater than that of the gasification furnace, so that the abrasion of the pulverized coal on the pipeline caused by the front-back pressure difference of the circulating pipeline is reduced as small as possible on the premise that the pulverized coal can flow forwards.

The pulverized coal is stored in the pulverized coal high-pressure storage tank 301, the circulating pressure P1 of the pulverized coal, P1-P is 0.5MPa, the stop valve 311 and the stop valve 314 are opened, the three-way valve 313 is adjusted to a circulating loop, the pulverized coal is adjusted by the adjusting angle valve 312, the flow of the pulverized coal is adjusted by a circulating pipeline, and the pulverized coal enters the pulverized coal low-pressure storage tank through the pulverized coal pressure reducing device 315 and the pressure reducing device 316 under the action of drainage gas to establish pulverized coal circulation.

In the powdered coal circulation process, high-pressure CO2 is generally adopted by the drainage gas and the conveying gas, so that the phenomenon that the throttling effect is too large before and after the drainage gas and the circulating powdered coal enter the pressure reducing device and the temperature drop is too large, water in the powdered coal is analyzed and blocked to form a circulating pipeline is avoided, and when the drainage gas is CO2, the gas temperature T1 is controlled at 120 ℃ before the drainage gas enters the pressure reducing device. When the circulating pressure P1 of the pulverized coal is more than or equal to 6.5MPa, in order to avoid overlarge one-stage pressure reduction throttling effect, the pulverized coal pressure reduction process is carried out in two stages, the circulating pressure is reduced to 2/3P1 in the first stage (the throttling effect of CO2 gas under higher pressure is larger, so the pressure reduction amplitude of a first-stage pressure reduction device is relatively smaller), and the circulating pressure is reduced to normal pressure from 2/3P1 in the second-stage pressure reduction.

Oxidizer purge loop setup procedure, as shown in FIG. 3:

opening an oxidant emptying shut-off valve 206, closing a feed pipeline shut-off valve 203 and a shut-off valve 204, setting the oxidant emptying amount preliminarily according to the flow of the pulverized coal, and adjusting a pressure adjusting valve or/and a flow limiting orifice plate of the pulverized coal oxidant emptying pipeline to ensure that the pressure P2, P2-P of the oxidant is 0.1MPa and P1 is more than P2.

Pulverized coal and oxidant pressures P1 and P2 were set according to: on the premise of ensuring that the pulverized coal and the oxidant have enough differential pressure to be conveyed to the gasification furnace, the differential pressure needs to be controlled within a reasonable range, otherwise, the excessive differential pressure disturbs the balance of a reaction zone in the gasification furnace, and the reaction in each zone is unbalanced and the component fluctuation is large. In order to avoid safety accidents caused by the fact that an oxidant enters a pulverized coal burner runner under the condition that a meter cannot detect timely due to flow breaking in the feeding process of a pulverized coal burner, the circulating pressure P1 of the pulverized coal is required to be greater than the pressure P2 of the oxidant.

(3) Linked control of dosing pulverized coal and oxidant

And after the circulation of the pulverized coal and the oxidant is established, starting a pulverized coal flow control and oxygen-coal ratio control system.

Controlling the flow of pulverized coal: the pulverized coal pipeline setting speed measuring device ST1 and the density measuring device DT1 can measure the speed and the density of the pulverized coal in the circulation process, the speed measuring device ST1 and the density measuring device DT1 can calculate the pulverized coal flow by checking through a pulverized coal flow computing device FIY1, then the pulverized coal flow is fed back to an oxygen-coal ratio control system and a pulverized coal flow transmission control device FIC1, and the pulverized coal flow transmission control device FIC1 adjusts the pulverized coal flow within a set range through an angle adjusting valve 312. The speed measuring device ST1 simultaneously feeds back a pulverized coal conveying speed signal to the conveying airflow transmission control device SIC1, the SIC1 feeds back a pulverized coal conveying airflow speed control signal to the conveying airflow transmission control device FIC2, and the conveying airflow transmission control device FIC2 adjusts the conveying airflow in a set range through a regulating valve arranged on a conveying air pipeline, so that the conveying speed of the pulverized coal is adjusted in the set range.

Controlling the oxygen-coal ratio: the oxidizer line is provided with an oxygen-to-coal ratio regulator 210, a pulverized coal flow signal from the pulverized coal line FIY1 and an oxidizer flow signal measured by an oxidizer line flow transmission control device FT1 are fed back to the oxygen-to-coal ratio regulator, and the oxygen-to-coal ratio regulator 210 calculates an appropriate oxygen amount according to the set oxygen-to-coal ratio and transmits an oxidizer flow control signal to the flow regulating valve 202 to regulate the flow of the oxidizer. The oxygen-coal ratio controller for feeding the pulverized coal is generally controlled to be 0.45Nm³/kg。

(4) The pressure and the flow of the pulverized coal and the oxidant are ensured to be within preset ranges, the gasifier operates stably, and the pulverized coal burner is charged under pressure on line.

And closing the pulverized coal circulation shut-off valve 314, simultaneously switching the pulverized coal pipeline three-way valve 313 to the feeding pipeline, closing the protective gas pipeline shut-off valve 318, and enabling the pulverized coal to enter the slurry gasification furnace through the pulverized coal burner.

The method comprises the steps of closing an oxidant emptying shut-off valve 206, opening oxidant feeding pipeline shut-off valves 203 and 204, shunting an oxidant pipeline shut-off valve 211, a shut-off valve 212, a shut-off valve 213 and a shut-off valve 214, enabling the oxidant to enter an oxygen flow distributor 205 through the shut-off valve 203 and the shut-off valve 204, distributing the oxidant in the oxygen flow distributor, closing a protective gas pipeline shut-off valve 318 entering a pulverized coal burner, and enabling the oxidant to enter a pulverized coal slurry gasification furnace through the pulverized coal burner and.

The amount of oxidant entering the pulverized coal burner accounts for 50% of the total oxidant amount, and the rest 50% of oxygen enters the coal slurry burner through a shut-off valve 211, a shut-off valve 212, a shut-off valve 213 and a shut-off valve 214 after being evenly distributed.

In another embodiment, a pulverized coal burner feeding method of a multi-nozzle slurry-powder gasification furnace is provided, which comprises the following steps:

(1) ensuring that the operating pressure P of the gasification furnace is within a normal range in a water-coal-slurry mode, and introducing protective gas to the top pulverized coal burner 103; keeping a shielding gas cut-off valve 318 and a shielding gas cut-off valve 209 of the pulverized coal pipeline and the pulverized coal oxidant pipeline in an open state, and enabling shielding gas to enter the pulverized coal burner to protect the pulverized coal burner;

(2) the on-line feeding flow of the pulverized coal and the oxidant is established through the pulverized coal circulation loop and the oxidant emptying pipeline.

The process of establishing the pulverized coal circulation is as shown in FIG. 2:

and (3) opening a drainage gas cut-off valve 319, introducing drainage gas into the low-pressure storage tank 301 through a pressure reducing device 315 and a pressure reducing device 316, and regulating the pressure of the drainage gas through a pressure regulating valve 320, wherein the pressure of the drainage gas is P3, and P is more than P3 and more than P1. The pressure of the drainage gas is less than that of the pulverized coal circulating pipeline and greater than that of the gasification furnace, so that the abrasion of the pulverized coal on the pipeline caused by the front-back pressure difference of the circulating pipeline is reduced as small as possible on the premise that the pulverized coal can flow forwards.

The pulverized coal is stored in the pulverized coal high-pressure storage tank 301, the circulating pressure P1 of the pulverized coal, P1-P is 0.75MPa, the stop valve 311 and the stop valve 314 are opened, the three-way valve 313 is adjusted to a circulating loop, the pulverized coal is adjusted by the adjusting angle valve 312, the flow of the pulverized coal is adjusted by a circulating pipeline, and the pulverized coal enters the pulverized coal low-pressure storage tank through the pulverized coal pressure reducing device 315 and the pressure reducing device 316 under the action of drainage gas to establish pulverized coal circulation.

In the fine coal circulation process, high-pressure CO2 is generally adopted by the drainage gas and the conveying gas, the temperature drop is too large for avoiding the too large throttling effect before and after the drainage gas and the circulation fine coal enter the pressure reducing device, water in the fine coal is analyzed and blocked to form a circulation pipeline, and the gas temperature T1 is controlled at 135 ℃ before the drainage gas enters the pressure reducing device when the drainage gas is CO 2. When the circulating pressure P1 of the pulverized coal is more than or equal to 6.5MPa, in order to avoid overlarge one-stage pressure reduction throttling effect, the pulverized coal pressure reduction process is carried out in two stages, the circulating pressure is reduced to 7/12P1 in the first stage (the throttling effect of CO2 gas under higher pressure is larger, so the pressure reduction amplitude of a first-stage pressure reduction device is relatively smaller), and the circulating pressure is reduced to normal pressure from 7/12P1 in the second-stage pressure reduction.

Oxidizer purge loop setup procedure, as shown in FIG. 3:

opening an oxidant emptying shut-off valve 206, closing a feed pipeline shut-off valve 203 and a shut-off valve 204, setting the oxidant emptying amount preliminarily according to the flow of the pulverized coal, and adjusting a pressure regulating valve or/and a flow limiting orifice plate of the pulverized coal oxidant emptying pipeline to ensure that the pressure P2, P2-P of the oxidant is 1.3MPa, and P1 is more than P2.

Pulverized coal and oxidant pressures P1 and P2 were set according to: on the premise of ensuring that the pulverized coal and the oxidant have enough differential pressure to be conveyed to the gasification furnace, the differential pressure needs to be controlled within a reasonable range, otherwise, the excessive differential pressure disturbs the balance of a reaction zone in the gasification furnace, and the reaction in each zone is unbalanced and the component fluctuation is large. In order to avoid safety accidents caused by the fact that an oxidant enters a pulverized coal burner runner under the condition that a meter cannot detect timely due to flow breaking in the feeding process of a pulverized coal burner, the circulating pressure P1 of the pulverized coal is required to be greater than the pressure P2 of the oxidant.

(3) Linked control of dosing pulverized coal and oxidant

And after the circulation of the pulverized coal and the oxidant is established, starting a pulverized coal flow control and oxygen-coal ratio control system.

Controlling the flow of pulverized coal: the pulverized coal pipeline setting speed measuring device ST1 and the density measuring device DT1 can measure the speed and the density of the pulverized coal in the circulation process, the speed measuring device ST1 and the density measuring device DT1 can calculate the pulverized coal flow by checking through a pulverized coal flow computing device FIY1, then the pulverized coal flow is fed back to an oxygen-coal ratio control system and a pulverized coal flow transmission control device FIC1, and the pulverized coal flow transmission control device FIC1 adjusts the pulverized coal flow within a set range through an angle adjusting valve 312. The speed measuring device ST1 simultaneously feeds back a pulverized coal conveying speed signal to the conveying airflow transmission control device SIC1, the SIC1 feeds back a pulverized coal conveying airflow speed control signal to the conveying airflow transmission control device FIC2, and the conveying airflow transmission control device FIC2 adjusts the conveying airflow in a set range through a regulating valve arranged on a conveying air pipeline, so that the conveying speed of the pulverized coal is adjusted in the set range.

Controlling the oxygen-coal ratio: the oxidant pipeline is provided with an oxygen-coal ratio regulator 210, a pulverized coal flow signal from the pulverized coal pipeline FIY1 and an oxidant flow signal measured by an oxidant pipeline flow transmission control device FT1 are fed back to the oxygen-coal ratio regulator 210 calculates the proper amount of oxidizer according to the set oxygen-to-coal ratio, and transmits an oxidizer flow control signal to the flow control valve 202 to adjust the oxidizer flow. The oxygen-coal ratio controller for feeding the pulverized coal is generally controlled to be 0.53Nm³/kg。

(4) The pressure and the flow of the pulverized coal and the oxidant are ensured to be within preset ranges, the gasifier operates stably, and the pulverized coal burner is charged under pressure on line.

And closing the pulverized coal circulation shut-off valve 314, simultaneously switching the pulverized coal pipeline three-way valve 313 to the feeding pipeline, closing the protective gas pipeline shut-off valve 318, and enabling the pulverized coal to enter the slurry gasification furnace through the pulverized coal burner.

The oxidant emptying shut-off valve 206 is closed, the oxidant feeding pipeline shut-off valves 203 and 204 are opened, the shunt oxidant pipeline shut-off valve 211, the shut-off valve 212, the shut-off valve 213 and the shut-off valve 214 are shunted, the oxidant enters the oxidant flow distributor 205 through the shut-off valve 203 and the shut-off valve 204, the oxidant is distributed in the oxidant flow distributor, the protective gas pipeline shut-off valve 318 entering the pulverized coal burner is closed, and the oxidant enters the pulverized coal slurry gasification furnace through the pulverized coal burner and the coal.

The amount of oxidant entering the pulverized coal burner accounts for 70% of the total oxidant amount, and the rest 30% of oxidant is evenly distributed and then enters the coal slurry burner through a shut-off valve 211, a shut-off valve 212, a shut-off valve 213 and a shut-off valve 214.

In another embodiment, a pulverized coal burner feeding method of a multi-nozzle slurry-powder gasification furnace is provided, which includes:

(1) ensuring that the operating pressure P of the gasification furnace is within a normal range in a water-coal-slurry mode, and introducing protective gas to the top pulverized coal burner 103; keeping a shielding gas cut-off valve 318 and a shielding gas cut-off valve 209 of the pulverized coal pipeline and the pulverized coal oxidant pipeline in an open state, and enabling shielding gas to enter the pulverized coal burner to protect the pulverized coal burner;

(2) the on-line feeding flow of the pulverized coal and the oxidant is established through the pulverized coal circulation loop and the oxidant emptying pipeline.

The process of establishing the pulverized coal circulation is as shown in FIG. 2:

and (3) opening a drainage gas cut-off valve 319, introducing drainage gas into the low-pressure storage tank 301 through a pressure reducing device 315 and a pressure reducing device 316, and regulating the pressure of the drainage gas through a pressure regulating valve 320, wherein the pressure of the drainage gas is P3, and P is more than P3 and more than P1. The pressure of the drainage gas is less than that of the pulverized coal circulating pipeline and greater than that of the gasification furnace, so that the abrasion of the pulverized coal on the pipeline caused by the front-back pressure difference of the circulating pipeline is reduced as small as possible on the premise that the pulverized coal can flow forwards.

The pulverized coal is stored in the pulverized coal high-pressure storage tank 301, the circulating pressure P1 of the pulverized coal, P1-P is 1.0MPa, the stop valve 311 and the stop valve 314 are opened, the three-way valve 313 is adjusted to a circulating loop, the pulverized coal is adjusted by the adjusting angle valve 312, the flow of the pulverized coal is adjusted by a circulating pipeline, and the pulverized coal enters the pulverized coal low-pressure storage tank through the pulverized coal pressure reducing device 315 and the pressure reducing device 316 under the action of drainage gas to establish pulverized coal circulation.

In the powdered coal circulation process, high-pressure CO2 is generally adopted by the drainage gas and the conveying gas, so that the phenomenon that the throttling effect is too large before and after the drainage gas and the circulating powdered coal enter the pressure reducing device and the temperature drop is too large, water in the powdered coal is analyzed and blocked to form a circulating pipeline is avoided, and when the drainage gas is CO2, the gas temperature T1 is controlled at 150 ℃ before the drainage gas enters the pressure reducing device. When the circulating pressure P1 of the pulverized coal is more than or equal to 6.5MPa, in order to avoid overlarge one-stage pressure reduction throttling effect, the pulverized coal pressure reduction process is carried out in two stages, the circulating pressure is reduced to 1/2P1 in the first stage (the throttling effect of CO2 gas under higher pressure is larger, so the pressure reduction amplitude of a first-stage pressure reduction device is relatively smaller), and the circulating pressure is reduced to normal pressure from 1/2P1 in the second-stage pressure reduction.

Oxidizer purge loop setup procedure, as shown in FIG. 3:

opening an oxidant emptying shut-off valve 206, closing a feed pipeline shut-off valve 203 and a shut-off valve 204, setting the oxidant emptying amount preliminarily according to the flow of the pulverized coal, and adjusting a pressure regulating valve or/and a flow limiting orifice plate of the pulverized coal oxidant emptying pipeline to ensure that the pressure P2, P2-P of the oxidant is 2.5MPa, and P1 is more than P2.

Pulverized coal and oxidant pressures P1 and P2 were set according to: on the premise of ensuring that the pulverized coal and the oxidant have enough differential pressure to be conveyed to the gasification furnace, the differential pressure needs to be controlled within a reasonable range, otherwise, the excessive differential pressure disturbs the balance of a reaction zone in the gasification furnace, and the reaction in each zone is unbalanced and the component fluctuation is large. In order to avoid safety accidents caused by the fact that an oxidant enters a pulverized coal burner runner under the condition that a meter cannot detect timely due to flow breaking in the feeding process of a pulverized coal burner, the circulating pressure P1 of the pulverized coal is required to be greater than the pressure P2 of the oxidant.

(3) Linked control of dosing pulverized coal and oxidant

And after the circulation of the pulverized coal and the oxidant is established, starting a pulverized coal flow control and oxygen-coal ratio control system.

Controlling the flow of pulverized coal: the pulverized coal pipeline setting speed measuring device ST1 and the density measuring device DT1 can measure the speed and the density of the pulverized coal in the circulation process, the speed measuring device ST1 and the density measuring device DT1 can calculate the pulverized coal flow by checking through a pulverized coal flow computing device FIY1, then the pulverized coal flow is fed back to an oxygen-coal ratio control system and a pulverized coal flow transmission control device FIC1, and the pulverized coal flow transmission control device FIC1 adjusts the pulverized coal flow within a set range through an angle adjusting valve 312. The speed measuring device ST1 simultaneously feeds back a pulverized coal conveying speed signal to the conveying airflow transmission control device SIC1, the SIC1 feeds back a pulverized coal conveying airflow speed control signal to the conveying airflow transmission control device FIC2, and the conveying airflow transmission control device FIC2 adjusts the conveying airflow in a set range through a regulating valve arranged on a conveying air pipeline, so that the conveying speed of the pulverized coal is adjusted in the set range.

Controlling the oxygen-coal ratio: the oxidizer line is provided with an oxygen-coal ratio regulator 210, a pulverized coal flow signal from the pulverized coal line FIY1 and an oxidizer flow signal measured by an oxidizer line flow transmission control device FT1 are fed back to the oxygen-coal ratio regulator, and the oxygen-coal ratio regulator 210 calculates an appropriate amount of oxidizer according to the set oxygen-coal ratio and transmits the oxidizer flow control signal to the flow regulating valve 202 to regulate the flow of the oxidizer. The pulverized coal feeding oxygen-coal ratio controller is generally controlled to be 0.60Nm 3/kg.

(4) The pressure and the flow of the pulverized coal and the oxidant are ensured to be within preset ranges, the gasifier operates stably, and the pulverized coal burner is charged under pressure on line.

And closing the pulverized coal circulation shut-off valve 314, simultaneously switching the pulverized coal pipeline three-way valve 313 to the feeding pipeline, closing the protective gas pipeline shut-off valve 318, and enabling the pulverized coal to enter the slurry gasification furnace through the pulverized coal burner.

The oxidant emptying shut-off valve 206 is closed, the oxidant feeding pipeline shut-off valves 203 and 204 are opened, the shunt oxidant pipeline shut-off valve 211, the shut-off valve 212, the shut-off valve 213 and the shut-off valve 214 are shunted, the oxidant enters the oxidant flow distributor 205 through the shut-off valve 203 and the shut-off valve 204, the oxidant is distributed in the oxidant flow distributor, the protective gas pipeline shut-off valve 318 entering the pulverized coal burner is closed, and the oxidant enters the pulverized coal slurry gasification furnace through the pulverized coal burner and the coal.

The amount of oxidant entering the pulverized coal burner accounts for 90% of the total oxidant amount, and the rest 10% of oxidant is evenly distributed and then enters the coal slurry burner through a cut-off valve 211, a cut-off valve 212, a cut-off valve 213 and a cut-off valve 214.

The invention aims to protect a pulverized coal burner feeding method of a multi-nozzle slurry gasification furnace, which comprises the following steps: introducing protective gas into a pulverized coal burner of a gasification furnace, wherein the gasification furnace operates in a coal water slurry mode; establishing a pulverized coal cycle at an initial pressure, and the pulverized coal cycle is established by multiple depressurization; and after the pulverized coal is circularly stabilized, feeding the pulverized coal and an oxidant into the gasification furnace through a feeding pipeline. Prevent that fine coal from circulating because once decompression, the too big difference in pressure leads to the too big difference in temperature of cooling to make water appear, cause to block up the circulating line, the emergence of the online material failure problem of throwing of fine coal. The high-pressure online continuous feeding of the pulverized coal burner under 6.5MPa is realized, the normal and stable feeding of the pulverized coal is ensured, the failure of the pulverized coal feeding and the occurrence of parking accidents are reduced, and the gasification efficiency is improved.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.