阅读说明：本技术 碎煤加压气化装置开车阶段的中压余热回收装置操作方法 (Operation method of medium-pressure waste heat recovery device in start-up stage of crushed coal pressure gasification device ) 是由 亢树新 侯永军 赵伟 侯雷雷 李金洲 刘宇杰 赵俊豪 于 2021-08-26 设计创作，主要内容包括：本发明属于煤气化技术领域,公开了一种碎煤加压气化装置开车阶段的中压余热回收装置操作方法,通过调节在碎煤加压气化炉通入4.5MPa、450℃的高压蒸汽进行碎煤加压气化装置暖管之前、在碎煤加压气化炉通入4.5MPa、450℃的高压蒸汽进行碎煤加压气化装置暖管时、在碎煤加压气化装置进行空气点火时、在碎煤加压气化装置进行切氧时、在气化炉并网时中压废热锅炉及汽包相关阀门的开度,使高温蒸汽与冷态金属缓慢接触,避免产生大量的冷凝液,解决了在碎煤加压气化装置开车阶段气相带液对设备耐火衬里浇筑料造成的毁坏性影响。(The invention belongs to the technical field of coal gasification, and discloses an operation method of a medium-pressure waste heat recovery device in a start-up stage of a crushed coal pressure gasification device, which is characterized in that high-temperature steam is slowly contacted with cold metal by adjusting the opening degrees of a medium-pressure waste heat boiler and related valves of a steam pocket when a crushed coal pressure gasification device is heated by introducing high-pressure steam of 4.5MPa and 450 ℃ before the crushed coal pressure gasification device is heated by introducing high-pressure steam of 4.5MPa and 450 ℃, the crushed coal pressure gasification device is ignited by air, the crushed coal pressure gasification device is subjected to oxygen cutting, and the gasification furnace is connected with a grid, so that a large amount of condensate is avoided, and the destructive influence of gas-phase liquid carried on equipment refractory lining pouring in the start-up stage of the crushed coal pressure gasification device is solved.)

1. An operation method of a medium-pressure waste heat recovery device in a start-up stage of a crushed coal pressure gasification device is characterized by comprising the following steps:

firstly, before introducing high-pressure steam with the pressure of 4.5MPa and the temperature of 450 ℃ into a crushed coal pressure gasification furnace to warm a crushed coal pressure gasification device, the steps are as follows:

a. closing a high-pressure steam main gate valve (1) and a high-pressure steam main bypass valve (2) which enter a crushed coal pressure gasification device at 4.5MPa and 450 ℃;

b. fully opening an emptying gate valve (3) and an emptying stop valve (4) at the top of a steam drum (22), switching a superheat section byproduct medium-pressure steam pressure regulating valve (5) of a medium-pressure waste heat boiler (21) from automatic regulation to a manual regulation mode, giving and outputting a 20% opening signal, and then, switching front and rear gate valves (6) of superheat section byproduct medium-pressure steam pressure to 50% opening;

c. opening the opening degree of a root valve (7) of a medium-pressure steam emptying silencer of a superheat section byproduct of a medium-pressure waste heat boiler (21) to 50%;

d. slowly opening a first section heat exchange section low-pressure preheating steam gate valve (9) of a medium-pressure waste heat boiler (21) to full open, slowly opening a 0.6MPa 180 ℃ low-pressure steam gate valve (8) to 20% of opening, slowly opening the low-pressure steam gate valve (8) to 40% of opening when the temperature of the first section steam heat exchange section low-pressure preheating steam gate valve (9) reaches 50 ℃, and slowly opening the low-pressure steam gate valve (8) to 60% of opening when the temperature of the first section steam heat exchange section low-pressure preheating steam gate valve (9) reaches 100 ℃;

e. monitoring a byproduct medium-pressure steam pressure regulating valve (5) at the overheating section of the medium-pressure waste heat boiler (21), and slowly opening a low-pressure steam gate valve (8) to 100% opening when the temperature of a pilot shower valve reaches 50 ℃;

f. closing a shell pass blowdown gate valve (10) of a first section of a heat exchange section of a medium-pressure waste heat boiler (21), monitoring the temperature of a first section of a heat exchanger riser (11) and the temperature of a first section of a heat exchanger downcomer (12) of the medium-pressure waste heat boiler (21) to reach 120 ℃, monitoring the temperature of a second section of the heat exchange section riser (13) and the temperature of a second section of the heat exchange section downcomer (14) of the medium-pressure waste heat boiler (21) to reach 110 ℃, monitoring and recording report data once every half hour, and enabling a steam drum manhole to reach 120 ℃;

g. opening a boiler water supply gate valve (15) to 100%, opening front and rear gate valves (17) of a liquid level regulating valve of a steam drum (22) to 100%, opening the liquid level regulating valve (16) to 20%, continuously monitoring the temperature of a first section ascending pipe (11) and a first section descending pipe (12) of a medium-pressure waste heat boiler (21), and continuously opening the liquid level regulating valve (16) to 50% when no obvious change exists;

h. when the liquid level of the steam pocket (22) is controlled to be 50%, closing the low-pressure steam gate valve (8), and opening a high-pressure preheating steam gate valve (18) of a first section of heat exchange section and a high-pressure preheating steam gate valve (19) of a second section of heat exchange section of the medium-pressure waste heat boiler (21) to 100% of opening;

i. monitoring the temperature of a first section of a riser (11) and a first section of a downcomer (12) of a heat exchange section of a medium-pressure waste heat boiler (21) to 130 ℃ for next operation;

secondly, when high-pressure steam with the pressure of 4.5MPa and the temperature of 450 ℃ is introduced into the crushed coal pressure gasification furnace for heating the crushed coal pressure gasification device, the steps are as follows:

a. fully opening a discharge valve (20) of the medium-pressure waste heat boiler (21), introducing high-pressure steam into the crushed coal pressure gasification device, and discharging the bottom guide shower of the medium-pressure waste heat boiler (21) for half an hour;

b. monitoring the temperatures of a first section of an ascending pipe (11) and a first section of a descending pipe (12) of a heat exchange section of a medium-pressure waste heat boiler (21) to respectively reach 130 ℃, monitoring the temperatures of a second section of the ascending pipe (13) and a second section of the descending pipe (14) of the heat exchange section of the medium-pressure waste heat boiler (21) to respectively reach 120 ℃, monitoring and recording report data once every half hour, and monitoring and recording the manhole of a steam drum to reach 130 ℃;

c. the pressure of a by-product medium-pressure steam pressure regulating valve (5) at the overheating section of the medium-pressure waste heat boiler (21) is controlled, the pressure is increased at the rate of 50KPa/min, the by-product steam pressure is synchronously increased along with the pressure of the gasification furnace, and the pressure is kept to be 0.5MPa higher than the pressure of the gasification furnace;

thirdly, when the crushed coal pressure gasification device performs air ignition, the steps are as follows: when the temperature of a first section of a riser (11) and a first section of a downcomer (12) of a first section of a heat exchange section of a monitored medium-pressure waste heat boiler (21) reaches 140 ℃, the condensate in the ash lock is emptied;

fourthly, when the crushed coal pressure gasification device carries out oxygen cutting, the steps are as follows:

a. discharging condensate every 15min by the gasification furnace;

b. monitoring the temperatures of a first section of an ascending pipe (11) and a first section of a descending pipe (12) of a heat exchange section of a medium-pressure waste heat boiler (21) to reach 150 ℃, respectively monitoring the temperatures of a second section of the ascending pipe (13) and a second section of the descending pipe (14) of the heat exchange section of the medium-pressure waste heat boiler (21) to reach 140 ℃, monitoring and recording report data once every half hour, and enabling a steam drum manhole to reach 150 ℃;

fifthly, when the gasification furnace is connected to the grid, the steps are as follows: the pressure of a superheat section byproduct medium-pressure steam pressure regulating valve (5) is set, the pressure of a medium-pressure waste heat boiler (21) is 0.5MPa higher than that of a gasification furnace, and a first section low-pressure preheating steam gate valve (9) and a second section high-pressure preheating steam gate valve (19) of the medium-pressure waste heat boiler (21) are closed.

2. The operation method of the medium-pressure waste heat recovery device in the start-up stage of the crushed coal pressure gasification device according to claim 1, wherein the upper part of the medium-pressure waste heat boiler (21) is a first section of heat exchange section, the middle part is a superheating section, and the lower part is a second section of heat exchange section.

Technical Field

The invention belongs to the technical field of coal gasification, and relates to an operation method of a medium-pressure waste heat recovery device in a start-up stage of a crushed coal pressure gasification device.

Background

The conventional method for starting the crushed coal pressurized gasification device generally comprises the steps of steam heating, steam temperature rise, air ignition, oxygen operation, pressure increasing and grid connection and the like, so that the gasification device can be started from a cold-state shutdown state to start and grid connection for putting into production operation, and because the system equipment of the crushed coal pressurized gasification device is in a cold-state process before starting, the cold-state average temperature of the equipment is between 10 and 15 ℃, and the temperature of the equipment is lower. In the steam temperature rise stage of the start-up process of the crushed coal pressure gasification device, 10000Kg/h, 4.5MPa and 450 ℃ high-pressure steam enters the system from the bottom of the gasification furnace and passes through materials and equipment in the crushed coal pressure gasification device, and 450 ℃ high-temperature steam inevitably generates a large amount of condensate when encountering 10-15 ℃ cold metal equipment.

Disclosure of Invention

The invention aims to provide an operation method of a medium-pressure waste heat recovery device in the driving stage of a crushed coal pressure gasification device, which enables high-temperature steam to slowly contact with cold metal, avoids generating a large amount of condensate and solves the destructive influence of gas-phase liquid-carrying on equipment refractory lining pouring materials in the driving stage of the crushed coal pressure gasification device.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides an operation method of a medium-pressure waste heat recovery device in the start-up stage of a crushed coal pressure gasification device, which comprises the following steps:

firstly, before introducing high-pressure steam with the pressure of 4.5MPa and the temperature of 450 ℃ into a crushed coal pressure gasification furnace to warm a crushed coal pressure gasification device, the steps are as follows:

a. closing a high-pressure steam main gate valve and a high-pressure steam main bypass valve which enter a crushed coal pressure gasification device at 4.5MPa and 450 ℃;

b. fully opening a vent gate valve and a vent stop valve at the top of a steam drum, switching a superheat section byproduct medium-pressure steam pressure regulating valve of a medium-pressure waste heat boiler from automatic regulation to a manual regulation mode, giving a signal of outputting 20% of opening degree, and then switching front and rear gate valves of superheat section byproduct medium-pressure steam pressure to 50% of opening degree;

c. opening the superheat section byproduct medium-pressure steam emptying silencer root valve of the medium-pressure waste heat boiler to 50%;

d. slowly opening a first section heat exchange section low-pressure preheating steam gate valve of the medium-pressure waste heat boiler to full open, slowly opening a 0.6MPa low-pressure steam gate valve at 180 ℃ to 20% of opening, slowly opening the low-pressure steam gate valve to 40% of opening when the temperature of a first section steam heat exchange section low-pressure preheating steam gate valve 9 reaches 50 ℃, and slowly opening the low-pressure steam gate valve to 60% of opening when the temperature of the first section steam heat exchange section low-pressure preheating steam gate valve reaches 100 ℃;

e. monitoring a byproduct medium-pressure steam pressure regulating valve of a superheat section of a medium-pressure waste heat boiler, and slowly opening a low-pressure steam gate valve to 100% of opening when the temperature of a back pilot shower valve reaches 50 ℃;

f. closing a shell pass blowdown gate valve of a first section of a heat exchange section of the medium-pressure waste heat boiler, monitoring the temperature of a first section of a heat exchanger riser and a first section of a heat exchanger downcomer of the medium-pressure waste heat boiler to reach 120 ℃, monitoring the temperature of a second section of the heat exchange section riser and a second section of the heat exchange section downcomer of the medium-pressure waste heat boiler to reach 110 ℃, monitoring and recording report data once every half hour, and enabling a steam drum manhole to reach 120 ℃;

g. opening the opening of a water supply gate valve of the boiler to 100%, opening front and rear gate valves of a liquid level regulating valve of a steam drum to 100% of the opening, opening the opening of the liquid level regulating valve to 20%, continuously monitoring the temperature of an ascending pipe and a descending pipe of a first section of a heat exchange section of the medium-pressure waste heat boiler, and continuously opening the liquid level regulating valve to 50% of the opening when no obvious change exists;

h. when the liquid level of the steam pocket is controlled to be 50%, closing the low-pressure steam gate valve, and opening the high-pressure preheating steam gate valve of the first section of heat exchange section and the high-pressure preheating steam gate valve of the second section of heat exchange section of the medium-pressure waste heat boiler to 100% opening;

i. monitoring the temperature of a riser of the first section of the heat exchange section and the temperature of a descending tube of the first section of the heat exchange section of the medium-pressure waste heat boiler to reach 130 ℃, and performing the next operation;

secondly, when high-pressure steam with the pressure of 4.5MPa and the temperature of 450 ℃ is introduced into the crushed coal pressure gasification furnace for heating the crushed coal pressure gasification device, the steps are as follows:

a. opening all discharge valves of the medium-pressure waste heat boiler, introducing high-pressure steam into the crushed coal pressure gasification device, and discharging the bottom guide shower of the medium-pressure waste heat boiler in half an hour;

b. monitoring the temperature of a first section of ascending pipe and a first section of descending pipe of a heat exchange section of the medium-pressure waste heat boiler to respectively reach 130 ℃, monitoring the temperature of a second section of ascending pipe and a second section of descending pipe of the heat exchange section of the medium-pressure waste heat boiler to respectively reach 120 ℃, monitoring and recording report data once every half hour, and enabling a steam drum manhole to reach 130 ℃;

c. the pressure of a by-product medium-pressure steam pressure regulating valve at the overheating section of the medium-pressure waste heat boiler is controlled, the pressure is increased at the rate of 50KPa/min, the by-product steam pressure is synchronously increased along with the pressure of the gasification furnace, and the pressure is kept to be 0.5MPa higher than the pressure of the gasification furnace;

thirdly, when the crushed coal pressure gasification device performs air ignition, the steps are as follows: when the temperature of a first section of ascending pipe and a first section of descending pipe of the heat exchange section of the monitored medium-pressure waste heat boiler reaches 140 ℃, the condensate in the ash lock is emptied;

fourthly, when the crushed coal pressure gasification device carries out oxygen cutting, the steps are as follows:

a. discharging condensate every 15min by the gasification furnace;

b. monitoring the temperature of a first section of an ascending pipe and a first section of a descending pipe of a heat exchange section of the medium-pressure waste heat boiler to respectively reach 150 ℃, monitoring the temperature of a second section of the ascending pipe and the temperature of a second section of the descending pipe of the heat exchange section of the medium-pressure waste heat boiler to respectively reach 140 ℃, monitoring and recording report data once every half hour, and enabling a steam drum manhole to reach 150 ℃;

fifthly, when the gasification furnace is connected to the grid, the steps are as follows: and setting the pressure of a superheat section byproduct medium-pressure steam pressure regulating valve, ensuring that the pressure of the medium-pressure waste heat boiler is 0.5MPa higher than that of the gasification furnace, and closing a first section heat exchange section low-pressure preheating steam gate valve and a second section heat exchange section high-pressure preheating steam gate valve of the medium-pressure waste heat boiler.

Preferably, the upper part of the medium-pressure waste heat boiler is a first section of heat exchange section, the middle part of the medium-pressure waste heat boiler is a superheating section, and the lower part of the medium-pressure waste heat boiler is a second section of heat exchange section.

Compared with the prior art, the invention has the beneficial effects that:

before the crushed coal pressure gasification device is introduced into the high-pressure steam heating pipe, during heating pipe, air ignition and oxygen cutting, related valves related to a steam drum and a medium-pressure waste heat boiler are gradually opened, the temperature of a first section of ascending pipe, a first section of descending pipe, a second section of ascending pipe and a second section of descending pipe of the medium-pressure waste heat boiler is monitored, the pressure increasing rate of the medium-pressure waste heat boiler is adjusted, high-temperature steam is slowly contacted with cold metal, a large amount of condensate is avoided, and the destructive influence of gas phase liquid carrying on equipment refractory lining pouring materials in the starting stage of the crushed coal pressure gasification device is solved.

Drawings

Fig. 1 is a structural view of the intermediate-pressure waste heat recovery apparatus of the present invention.

The reference numbers in the drawings: 1 is a high-pressure steam main gate valve, 2 is a high-pressure steam main bypass valve, 3 is a vent gate valve, 4 is a vent stop valve, 5 is a superheat section by-product medium-pressure steam pressure regulating valve, 6 is a superheat section by-product medium-pressure steam pressure front and back gate valve, 7 is a superheat section by-product medium-pressure steam vent muffler root valve, 8 is a low-pressure steam gate valve, 9 is a first section heat exchange section low-pressure preheating steam gate valve, 10 is a first section heat exchange section shell pass blowdown gate valve, 11 is a first section heat exchanger ascending pipe, 12 is a first section heat exchanger descending pipe, 13 is a second section heat exchange section ascending pipe, 14 is a second section heat exchange section descending pipe, 15 is a boiler water supply gate valve, 16 is a liquid level regulating valve, 17 is a liquid level regulating valve front and back gate valve, 18 is a first section high-pressure preheating steam gate valve, 19 is a second section high-pressure preheating steam gate valve, 20 is a discharge valve, 21 is a medium-pressure waste heat boiler, 22 is a steam drum, and 23 is a steam drum blowdown sampling cooler.

Detailed Description

The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. The test methods in the following examples are conventional methods unless otherwise specified.

Example one

As shown in fig. 1, the operation method of the medium-pressure waste heat recovery device in the start-up stage of the crushed coal pressure gasification device, in which the upper part of the medium-pressure waste heat boiler 21 is a first section of heat exchange section, the middle part is a superheating section, and the lower part is a second section of heat exchange section, comprises the following steps:

firstly, before introducing high-pressure steam with the pressure of 4.5MPa and the temperature of 450 ℃ into a crushed coal pressure gasification furnace to warm a crushed coal pressure gasification device, the steps are as follows:

a. closing a high-pressure steam main gate valve 1 and a high-pressure steam main bypass valve 2 which enter a crushed coal pressure gasification device at 4.5MPa and 450 ℃;

b. fully opening a vent gate valve 3 and a vent stop valve 4 at the top of a steam drum 22, switching a superheat section by-product medium-pressure steam pressure regulating valve 5 of a medium-pressure waste heat boiler 21 from automatic regulation to a manual regulation mode, giving and outputting a 20% opening signal, and then opening front and back gate valves 6 of superheat section by-product medium-pressure steam pressure to 50%;

c. opening the superheat section byproduct medium-pressure steam emptying silencer root valve 7 of the medium-pressure waste heat boiler 21 to 50%;

d. slowly opening a first section heat exchange section low-pressure preheating steam gate valve 9 of the medium-pressure waste heat boiler 21 to full open, slowly opening a 0.6MPa and 180 ℃ low-pressure steam gate valve 8 to 20% of opening, slowly opening the low-pressure steam gate valve 8 to 40% of opening when the temperature of the first section steam heat exchange section low-pressure preheating steam gate valve 9 reaches 50 ℃, and slowly opening the low-pressure steam gate valve 8 to 60% of opening when the temperature of the first section steam heat exchange section low-pressure preheating steam gate valve 9 reaches 100 ℃;

e. monitoring a by-product medium-pressure steam pressure regulating valve 5 at the overheating section of the medium-pressure waste heat boiler 21, and slowly opening a low-pressure steam gate valve 8 to 100% opening when the temperature of a pilot shower valve reaches 50 ℃;

f. closing a shell pass blowdown gate valve 10 of a first section of a heat exchange section of a medium-pressure waste heat boiler 21, monitoring the temperatures of a first section of a heat exchanger riser 11 and a first section of a heat exchanger downcomer 12 of the medium-pressure waste heat boiler 21 to reach 120 ℃, monitoring the temperatures of a second section of the heat exchange section riser 13 and a second section of the heat exchange section downcomer 14 of the medium-pressure waste heat boiler 21 to reach 110 ℃, monitoring and recording report data once every half hour, and enabling a steam drum manhole to reach 120 ℃;

g. opening 15 opening degrees of a boiler water supply gate valve to 100%, opening 17 opening degrees of front and rear gate valves of a liquid level regulating valve of a steam drum 22 to 100%, opening 20 opening degrees of a liquid level regulating valve 16, continuously monitoring the temperatures of a first section of a rising pipe 11 and a first section of a descending pipe 12 of a heat exchange section of a medium-pressure waste heat boiler 21, and continuously opening the liquid level regulating valve 16 to 50% opening degrees when no obvious change exists;

h. when the liquid level of the steam drum 22 is controlled to be 50%, closing the low-pressure steam gate valve 8, and opening the high-pressure preheating steam gate valve 18 of the first section of the heat exchange section and the high-pressure preheating steam gate valve 19 of the second section of the heat exchange section of the medium-pressure waste heat boiler 21 to 100% of opening;

i. monitoring the temperature of a first section of a riser 11 and a first section of a downcomer 12 of a heat exchange section of the medium-pressure waste heat boiler 21 to 130 ℃ and then carrying out the next operation;

secondly, when high-pressure steam with the pressure of 4.5MPa and the temperature of 450 ℃ is introduced into the crushed coal pressure gasification furnace for heating the crushed coal pressure gasification device, the steps are as follows:

a. fully opening the discharge valve 20 of the medium-pressure waste heat boiler 21, introducing high-pressure steam into the crushed coal pressure gasification device, and discharging the bottom guide shower of the medium-pressure waste heat boiler 21 for half an hour;

b. monitoring the temperatures of a first section of an ascending pipe 11 and a first section of a descending pipe 12 of a heat exchange section of the medium-pressure waste heat boiler 21 to respectively reach 130 ℃, monitoring the temperatures of a second section of the ascending pipe 13 and a second section of the descending pipe 14 of the heat exchange section of the medium-pressure waste heat boiler 21 to respectively reach 120 ℃, monitoring and recording report data once every half hour, and monitoring and recording the manhole of a steam drum to reach 130 ℃;

c. the pressure of the medium pressure waste heat boiler 21 is controlled by a medium pressure steam pressure regulating valve 5 at the overheating section, the pressure is increased at the rate of 50KPa/min, the pressure of the by-product steam is synchronously increased along with the pressure of the gasification furnace, and the pressure is kept to be 0.5MPa higher than the pressure of the gasification furnace;

thirdly, when the crushed coal pressure gasification device performs air ignition, the steps are as follows: when the temperature of a first section of a rising pipe 11 and a first section of a descending pipe 12 of a heat exchange section of a monitored medium-pressure waste heat boiler 21 reaches 140 ℃, the condensate in the ash lock is emptied;

fourthly, when the crushed coal pressure gasification device carries out oxygen cutting, the steps are as follows:

a. discharging condensate every 15min by the gasification furnace;

b. monitoring the temperatures of a first section of an ascending pipe 11 and a first section of a descending pipe 12 of a heat exchange section of the medium-pressure waste heat boiler 21 to reach 150 ℃, monitoring the temperatures of a second section of the ascending pipe 13 and a second section of the descending pipe 14 of the heat exchange section of the medium-pressure waste heat boiler 21 to reach 140 ℃, monitoring and recording report data once every half hour, and monitoring and recording the manhole of a steam drum to reach 150 ℃;

fifthly, when the gasification furnace is connected to the grid, the steps are as follows: and setting the pressure of a superheat section byproduct medium-pressure steam pressure regulating valve 5, ensuring that the pressure of the medium-pressure waste heat boiler 21 is 0.5MPa higher than the pressure of the gasification furnace, and closing a first section heat exchange section low-pressure preheating steam gate valve 9 and a second section heat exchange section high-pressure preheating steam gate valve 19 of the medium-pressure waste heat boiler 21.

The above-mentioned embodiments are merely preferred embodiments of the present invention, which are merely illustrative and not restrictive, and it should be understood that other embodiments may be easily made by those skilled in the art by replacing or changing the technical contents disclosed in the specification, and therefore, all changes and modifications that are made on the principle of the present invention should be included in the scope of the claims of the present invention.