阅读说明：本技术 循环流化床锅炉启炉方法 (Boiler starting method of circulating fluidized bed boiler ) 是由 张刚 刘海建 霍学斌 吴松怡 隋盈鑫 李军明 于 2018-07-25 设计创作，主要内容包括：本发明公开了一种循环流化床气化炉启炉方法,其方法包括烘炉升温升压阶段、建床层准备阶段、建床层阶段、合成气处理阶段。本发明的优点在于,利用本发明的方法进行启炉时,气化炉的升温升压过程同时进行,解决传统气化炉启炉方法中升温、升压不能同时进行；以不做加温处理的混合气作为煤粉输送气和流化剂,可以使气化炉内煤粉维持较好的流化状态,避免气化炉结渣事故的发生,缩短了升温升压进程,启炉时间长短,不合格合成气量低,降低了资源浪费,减轻了企业环保负荷；升温过程主要依靠烘炉气,烘炉气热效率高,降低了点火煤粉用量,降低了企业生产成本。(The invention discloses a method for starting a circulating fluidized bed gasification furnace, which comprises a furnace baking temperature rise and pressure rise stage, a bed building preparation stage, a bed building stage and a synthetic gas treatment stage. The method has the advantages that when the method is used for starting the gasifier, the temperature and pressure raising processes of the gasifier are carried out simultaneously, so that the problem that the temperature and pressure raising processes can not be carried out simultaneously in the traditional gasifier starting method is solved; the mixed gas without heating treatment is used as the pulverized coal conveying gas and the fluidizing agent, so that the pulverized coal in the gasification furnace can maintain a better fluidizing state, the occurrence of slag bonding accidents of the gasification furnace is avoided, the temperature and pressure rise process is shortened, the start time is short, the unqualified synthetic gas amount is low, the resource waste is reduced, and the environmental protection load of enterprises is lightened; the temperature rise process mainly depends on the oven gas, the oven gas has high thermal efficiency, the ignition coal powder consumption is reduced, and the production cost of enterprises is reduced.)

1. The method for starting the circulating fluidized bed gasifier is characterized by comprising the steps of firstly introducing preheating oven gas into a gasifier system to carry out temperature rise and pressure rise operation on the gasifier system, obtaining circulating gas after the preheating oven gas passes through the gasifier system, mixing and recycling part of the circulating gas with the preheating oven gas through a compressor in the temperature rise and pressure rise operation process, controlling the temperature rise and pressure rise rate of the gasifier until the furnace top temperature T of the gasifier is reached₄Is lifted to T₄650 ℃ at 450-₃Lifting to P of 2.0MPa or less₃Less than 3.5 MPa; and then, stopping mixing part of the circulating gas with the preheating furnace drying gas, starting to convey pulverized coal into the gasification furnace, taking the circulating gas as the conveying gas of the pulverized coal, starting to convey a gasifying agent into the gasification furnace when the thickness of the bed layer in the gasification furnace is 2m, and treating the synthetic gas generated by the gasification furnace.

2. The furnace starting method of the circulating fluidized bed gasification furnace according to claim 1, which comprises the following steps:

a furnace baking temperature rise and pressure rise stage: conveying the oven gas to a preheater through an oven gas pipeline, and heating to 100 ℃ to obtain preheated oven gas; opening a distribution plate valve and a central pipe valve, respectively conveying the preheated oven gas into a distribution plate gasification agent pipeline and a central pipe gasification agent pipeline, and further lifting the internal temperature of the gasification furnace and the cyclone separator through the preheated oven gas; the preheating oven gas after heat exchange with the gasification furnace and the cyclone separator is subjected to dust removal by a dust remover and heat recovery by a waste heat boiler in sequence to obtain the circulating gas; starting a circulating gas valve, conveying the circulating gas to the oven gas pipeline through the compressor to be mixed with the oven gas, wherein the mixing volume ratio of the circulating gas to the oven gas is 1-2: 10, obtaining mixed gas; the mixed gas is conveyed into the preheater and heated to 100 ℃ to obtain the preheated mixed gas, and the preheated mixed gas is gasified through the distribution plate gasification agent pipeline and the central pipe respectivelyAn agent pipeline enters the gasification furnace and the cyclone separator to raise the internal temperature of the gasification furnace and the cyclone separator; repeating the operation, gradually increasing the temperature of the preheated mixed gas by controlling the heat medium inlet amount of the preheater and the delivery amount of the mixed gas, and controlling the temperature rise rate in the gasification furnace to be 25 ℃/h and the pressure rise rate to be 0.2 MPa/h; up to T₄＝450-650℃、2.0MPa≤P₃If the pressure is less than 3.5MPa, the temperature and pressure raising stage of the oven is finished;

bed building preparation stage: after the temperature and pressure raising stage of the drying oven is completed, closing a circulating gas valve, continuously conveying the preheated drying oven gas into the gasification oven through the distribution plate gasification agent pipeline, and continuously conveying the circulating gas into the gasification oven through the central pipe gasification agent pipeline; charging the interior of a coal lock, when the internal pressure of the coal lock is at least 200KPa higher than the internal pressure of the gas chamber of the gasification furnace, opening a coal outlet valve, a coal inlet valve and a pulverized coal conveying gas valve, taking the circulating gas as pulverized coal conveying gas, adjusting the opening of the pulverized coal conveying gas valve, keeping the internal pressure of a pulverized coal pipeline 10-50KPa higher than the internal pressure of the gas chamber of the gasification furnace, and completing the bed building preparation stage;

a bed building stage: after the bed building preparation stage is completed, when the furnace top temperature T is reached₄Is lifted to T₄600 ℃, said furnace top pressure P₃Lifting to P less than or equal to 3.0MPa₃When the pressure is less than 3.5MPa, conveying pulverized coal into the gasification furnace through a coal bunker and the coal lock, and when the thickness of the bed layer in the gasification furnace is 2m, conveying the gasification agent into the gasification furnace through the distribution plate gasification agent pipeline and the central pipe gasification agent pipeline, and controlling the temperature rise rate of the gasification furnace to be 30-60 ℃/h and the pressure rise rate to be 0.2-0.3 MPa/h; in this process, the recycle gas acts as a fluidizing agent and stabilizes the furnace top temperature T₄Maintaining the fluidization state of the coal dust in the gasification furnace by using the preheating oven gas as a fluidizing agent at 600 ℃; when the thickness of the bed layer in the gasification furnace is continuously increased, closing the distribution plate valve and the central pipe valve, and stopping conveying the preheating oven gas and the circulating gas;

and (3) a synthesis gas treatment stage: in the bed building stage, after the circulating gas valve is closed, in order to maintain the furnace top pressure P₃The synthesis gas produced by the gasification furnace needs to be treated; when the synthetic gas line pressure P₅When the pressure is higher than 8.0MPa, opening an emptying valve to empty the synthesis gas; when the oxygen content of the synthesis gas is more than 0.1 percent, the pressure P of the synthesis gas pipeline₅When the process design pressure is less than the process design pressure, closing the emptying valve, opening a flare valve, and sending the synthesis gas to a flare treatment system through a flare pipeline; when the oxygen content of the synthesis gas is less than or equal to 0.1 percent and the pressure P of the synthesis gas pipeline₅And when the process design pressure is not less than the process design pressure, closing the torch valve and opening the crude gas valve, and conveying the synthesis gas to a methanol synthesis working section through a qualified gas pipeline.

3. The furnace start-up method of the circulating fluidized bed gasifier start-up system according to claim 2, wherein the oven gas is any one or a combination of nitrogen and carbon dioxide, and when the oven gas comprises the nitrogen and the carbon dioxide, the nitrogen and the carbon dioxide can be mixed in any ratio.

The technical field is as follows:

the invention relates to the field of coal chemical industry, in particular to a method for starting a circulating fluidized bed gasification furnace.

Background art:

at present, three fluidized bed gasification processes, namely coal pressurized catalytic gasification, ash agglomeration and U-gas, are adopted, a traditional three-stage furnace starting mode of furnace heating, material feeding and bed building and system pressure boosting is adopted, and the heating and pressure boosting processes are carried out strictly according to requirements. The traditional furnace starting mode has the following problems: 1. and (3) oven drying: in the traditional method, flue gas generated after combustion of liquefied petroleum gas or natural gas is used as a heat source for baking the furnace, the temperature of the furnace is increased to 850 ℃ from room temperature for about 24 hours, and the time consumption in the temperature increasing process is long; 2. feeding and bed building processes: after the temperature of the furnace rises to 580 ℃, introducing a gasifying agent into the furnace and adding coal powder, wherein the coal powder directly reduces the temperature of the furnace after being added into the furnace due to low temperature of the coal powder, so that the coal gasification reaction cannot be normally carried out; therefore, part of the pulverized coal input at this stage is combusted to increase the furnace temperature, and the other part of the pulverized coal participates in the gasification reaction, but because the furnace temperature and the furnace pressure can not meet the gasification reaction requirement, the pulverized coal is not completely gasified and can only be discharged out of the furnace along with the synthesis gas, the synthesis gas has low quality and high oxygen content, cannot enter the subsequent working section and is sent to a torch for treatment, so the pulverized coal is easy to explode, and can only be discharged into the atmosphere, thereby the resources are seriously wasted, and the environment is polluted; 3. and (3) boosting: before the boosting process starts, equipment and pipelines need to be heated and tightened to ensure the air tightness of the equipment and the pipelines, then the pressure is gradually increased from the normal pressure to a preset pressure value according to the actual condition, and as the fluidized state of furnace burden in a furnace is violently changed at the boosting key point (generally 1.0MPa, 2.0MPa and 3.0MPa), once the conditions of unstable flow pattern or local overtemperature and the like are generated, the slag bonding accident of the gasification furnace can be caused; therefore, when the pressure rises from one pressure key point to another pressure key point, the pressure rising rate is required to be gradually reduced, and the time duration of maintaining after reaching the higher pressure key point is also required to be continuously increased so as to ensure that the temperature and the pressure of the bed in the fluidized bed gasification furnace are in a controllable range and have a better fluidization state; therefore, the boosting process lasts a long time, typically several days. The problems are more obvious along with the increase of the volume of the circulating fluidized bed gasification furnace, and comprehensively, the problems of long operation period, serious resource waste, complicated flow, high difficulty and serious environmental pollution exist in the starting process of the traditional circulating flow bed gasification furnace.

The invention content is as follows:

the invention aims to provide a furnace starting method of a circulating fluidized bed gasification furnace, which has the advantages of short operation period, resource waste reduction, operation difficulty reduction and environmental pollution relief.

The purpose of the invention is implemented by the following technical scheme: a method for starting a circulating fluidized bed gasifier comprises the steps of firstly, introducing preheating oven gas into a gasifier system to carry out temperature rise and pressure rise operation on the gasifier system, enabling the preheating oven gas to pass through the gasifier system to obtain circulating gas, mixing and recycling part of the circulating gas with the preheating oven gas through a compressor in the temperature rise and pressure rise operation process, controlling the temperature rise and pressure rise rate of the gasifier until the furnace top temperature T of the gasifier is reached₄Is lifted to T₄650 ℃ at 450-₃Lifting to P of 2.0MPa or less₃Less than 3.5 MPa; and then, stopping mixing part of the circulating gas with the preheating furnace drying gas, starting to convey pulverized coal into the gasification furnace, taking the circulating gas as the conveying gas of the pulverized coal, starting to convey a gasifying agent into the gasification furnace when the thickness of the bed layer in the gasification furnace is 2m, and treating the synthetic gas generated by the gasification furnace.

Further, the method specifically comprises the following steps:

a furnace baking temperature rise and pressure rise stage: conveying the oven gas to a preheater through an oven gas pipeline, and heating to 100 ℃ to obtain preheated oven gas; opening a distribution plate valve and a central pipe valve, conveying the preheated oven gas into a distribution plate gasification agent pipeline and a central pipe gasification agent pipeline respectively, and increasing the internal temperature of the gasification furnace and the cyclone separator through the preheated oven gas; the preheating oven gas after heat exchange with the gasification furnace and the cyclone separator is subjected to dust removal by a dust remover and heat recovery by a waste heat boiler to obtain circulating gas; opening a circulating gas valve, and conveying the circulating gas to a compressorThe oven gas pipeline is mixed with the oven gas, and the mixing volume ratio of the circulating gas to the oven gas is 1-2: 10, obtaining mixed gas; the mixed gas is conveyed into the preheater and heated to 100 ℃ to obtain preheated mixed gas, and the preheated mixed gas enters the gasification furnace and the cyclone separator through the distribution plate gasification agent pipeline and the central pipe gasification agent pipeline respectively to raise the internal temperature of the gasification furnace and the cyclone separator; repeating the operation, gradually increasing the temperature of the preheated mixed gas by controlling the heat medium inlet amount of the preheater and the delivery amount of the mixed gas, and controlling the temperature rise rate in the gasification furnace to be 25 ℃/h and the pressure rise rate to be 0.2 MPa/h; until the furnace top temperature T of the gasification furnace₄Is lifted to T₄650 ℃ at 450-₃Lifting to P of 2.0MPa or less₃If the pressure is less than 3.5MPa, the temperature and pressure raising stage of the oven is finished;

bed building preparation stage: after the temperature and pressure raising stage of the drying oven is completed, closing a circulating gas valve, continuously conveying the preheated drying oven gas into the gasification oven through the distribution plate gasification agent pipeline, and continuously conveying the circulating gas into the gasification oven through the central pipe gasification agent pipeline; charging the interior of a coal lock, when the internal pressure of the coal lock is at least 200KPa higher than the internal pressure of the gas chamber of the gasification furnace, opening a coal outlet valve, a coal inlet valve and a pulverized coal conveying gas valve, taking the circulating gas as pulverized coal conveying gas, adjusting the opening of the pulverized coal conveying gas valve, keeping the internal pressure of a pulverized coal pipeline 10-50KPa higher than the internal pressure of the gas chamber of the gasification furnace, and completing the bed building preparation stage;

a bed building stage: after the bed building preparation stage is completed, when the furnace top temperature T is reached₄Is lifted to T₄600 ℃, said furnace top pressure P₃Lifting to P less than or equal to 3.0MPa₃When the pressure is less than 3.5MPa, pulverized coal is conveyed into the gasification furnace through the coal bunker and the coal lock, when the thickness of the bed layer in the gasification furnace is 2m, a gasification agent is conveyed into the gasification furnace through the distribution plate gasification agent pipeline and the central pipe gasification agent pipeline, the temperature rise rate of the gasification furnace is controlled to be 30-60 DEG CThe pressure increasing rate is 0.2-0.3 MPa/h; in this process, the recycle gas acts as a fluidizing agent and stabilizes the furnace top temperature T₄Maintaining the fluidization state of the coal dust in the gasification furnace by using the preheating oven gas as a fluidizing agent at 600 ℃; when the thickness of the bed layer in the gasification furnace is continuously increased, closing the distribution plate valve and the central pipe valve, and stopping conveying the preheating oven gas and the circulating gas;

and (3) a synthesis gas treatment stage: in the bed building stage, after the circulating gas valve is closed, in order to maintain the furnace top pressure P₃The synthesis gas produced by the gasification furnace needs to be treated; when the synthetic gas line pressure P₅When the pressure is higher than 8.0MPa, opening an emptying valve to empty the synthesis gas; when the oxygen content of the synthesis gas is more than 0.1 percent, the pressure P of the synthesis gas pipeline₅When the process design pressure is less than the process design pressure, closing the emptying valve, opening a flare valve, and sending the synthesis gas to a flare treatment system through a flare pipeline; when the oxygen content of the synthesis gas is less than or equal to 0.1 percent and the pressure P of the synthesis gas pipeline₅And when the process design pressure is not less than the process design pressure, closing the torch valve and opening the crude gas valve, and conveying the synthesis gas to a methanol synthesis working section through a qualified gas pipeline.

Further, the oven gas is any one or combination of nitrogen or carbon dioxide, and when the oven gas comprises the nitrogen and the carbon dioxide, the nitrogen and the carbon dioxide can be mixed according to any proportion.

The invention has the advantages that: 1. the heating and boosting processes of the gasification furnace are carried out simultaneously, so that the problems that the heating and boosting can not be carried out simultaneously, the furnace starting time is long, the ignition coal is wasted much, the environmental pollution is serious and the heat efficiency is low in the traditional gasification furnace starting method are solved; in the invention, the furnace top temperature T of the gasification furnace is firstly measured₄Raising the temperature to over 450 ℃ and the furnace top pressure P₃Increasing the pressure to 2.0MPa or less P₃Less than 3.5MPa, and preparation is made for adding the coal powder; then the furnace top temperature T is measured₄Rise to T₄600 ℃ and furnace top pressure P₃Increasing the pressure to be less than or equal to 3.0MPa and less than or equal to P₃If the pressure is less than 3.5MPa, adding pulverized coal to build a bed layer; in the above process, the temperature and pressure rise is fast due to the shape of the inside of the gasifierUnder the conditions of high temperature and high pressure, the gas phase density in the unit volume in the gasification furnace is increased, the contact probability of a gasification agent and the coal powder is increased, further, the gasification reaction of the coal powder is accelerated, the coal powder reacts quickly to emit large amount of heat, the temperature rise and pressure rise processes are accelerated, and the temperature rise, the pressure rise and the feeding can be carried out simultaneously; 2. The heating process mainly depends on the oven gas, the oven gas is heated by the preheater and then enters the gasification furnace and the cyclone separator for heat exchange, and the oven gas after heat exchange is treated by the flue gas purification system and then is recycled by the flue gas circulation system, so that the heat efficiency of the oven gas is improved, the ignition coal powder consumption is reduced, the resources are saved, and the production cost of enterprises is reduced; 3. the temperature and pressure rising process is shortened, the unqualified synthesis gas amount generated in the temperature and pressure rising process is reduced, the resource waste is reduced, only part of unqualified synthesis gas with high oxygen content is discharged, and the rest unqualified synthesis gas with low oxygen content can be sent to a torch for treatment, so that the environmental protection load of enterprises is reduced; 4. the mixed gas without heating treatment is used as the pulverized coal conveying gas and the fluidizing agent, so that the pulverized coal in the gasification furnace can maintain a better fluidized state, and the occurrence of slag bonding accidents of the gasification furnace is avoided, thereby shortening the pressure boosting process.

Description of the drawings:

in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of example 1.

1 part of gasification furnace, 1 part of furnace top temperature sensor, 1 part of furnace bottom temperature sensor, 1 part of gas chamber, 1 part of furnace body pressure sensor, 1 part of gas chamber pressure sensor, 1 part of furnace top pressure sensor, 1 part of distribution plate gasification agent pipeline, 1 part of central pipe gasification agent pipeline, 1 part of distribution plate gasification agent pressure sensor, 1 part of central pipe gasification agent pressure sensor, 1 part of coal inlet system, 2 part of coal bunker, 2 part of coal lock, 2 part of coal powder pipeline, 2 part of coal outlet valve, 2 part of coal inlet valve, 2 part of coal drying gas system, 3 part of furnace drying gas pipeline, 3 part of preheater, 3 part of heat medium pipeline, 3 part of furnace drying gas valve, 3-5 parts of oven gas pressure sensor, 3-6 parts of inlet gas temperature sensor, 3-7 parts of heat medium valve, 3-8 parts of distribution plate valve, 3-9 parts of central pipe valve, 4 parts of flue gas purification system, 4-1 parts of cyclone separator, 4-2 parts of dust remover, 4-3 parts of waste heat boiler, 4-4 parts of flue gas pressure sensor, 4-5 parts of synthesis gas temperature sensor, 4-6 parts of return material pipeline, 4-7 parts of return material pressure sensor, 4-8 parts of return material temperature sensor, 4-9 parts of synthesis gas pipeline, 4-10 parts of qualified gas pipeline, 4-11 parts of torch pipeline, 4-12 parts of vent pipeline, 4-13 parts of synthesis gas pressure sensor, 4-14 parts of crude gas valve, 4-15 parts of torch valve, 4-16 parts of vent valve, 5 parts of flue gas circulation system and 5-1 parts of compressor, 5-2 parts of circulating gas pipeline, 5-3 parts of circulating gas valve, 5-4 parts of coal powder conveying gas valve and 5-5 parts of circulating gasification valve.

The specific implementation mode is as follows: