Method for realizing quick starting of coke oven chimney

Abstract

The present application belongs to the field of coal coking, and particularly relates to a method for realizing quick use of coke oven chimney, characterized in that the method comprises an injection gas source, a pressure relief valve, a jet unit and a connecting gas path, the injection gas source is a container with a certain volume for storing high-pressure gas or a facility capable of providing a stable gas source, the injection gas source is connected with the jet unit through the connecting gas path, and the jet unit is uniformly arranged in the circumferential direction at the root of the coke oven chimney. The pressure relief valve is a normally closed valve, which is opened in linkage with the coke oven flue total gate or is opened alone after receiving an emergency opening instruction. The method has the advantages that: the coke oven chimney device does not need to be considered, no additional energy consumption is needed, coke oven flue gas waste heat can be fully recovered, the utmost energy efficiency utilization of the coke oven production process is realized, the normal production of the coke oven does not need to be ensured by maintaining the normal operation of the coke oven desulfurization and denitrification system through fuel consumption, the operation cost can be significantly reduced, and the method is operated at nearly zero cost without continuous supply of high-pressure gas.

Description

Technical Field

[0001] This invention belongs to the field of coal coking, and in particular relates to a method for rapidly starting up a coke oven chimney. Background Technology

[0002] Coke oven flue gas is the waste gas produced during the coking process, generated from the combustion of fuel to provide the necessary heat energy for the coke oven. It contains certain amounts of air pollutants such as NOx and SO2, as well as the greenhouse gas CO2, and carries approximately 17% of the waste heat output from the coke oven. With increasingly stringent environmental laws and regulations and the need for green development, the treatment of air pollutants such as NOx and SO2 in coke oven flue gas has become an indispensable part of coking production. Furthermore, the full and effective recovery of the waste heat carried by the coke oven flue gas is essential for achieving optimal energy efficiency in coking.

[0003] In existing coke oven flue gas desulfurization and denitrification technologies, coke oven flue gas with a temperature of 180℃~300℃, after desulfurization and denitrification, is discharged into the coke oven chimney by the desulfurization and denitrification system fans. The pressure required for normal production of the coke oven heating system is provided by the desulfurization and denitrification system fans. To ensure normal coke oven production in the event of a sudden failure of the coke oven flue gas desulfurization and denitrification system, hot standby measures are required for the coke oven chimney to maintain the temperature of the gas flowing inside the chimney at 100℃~130℃ or higher. Therefore, certain technical measures are typically adopted to continuously discharge gas at a temperature of 100℃~130℃ or higher through the coke oven chimney, keeping the chimney in a hot standby state. For example:

[0004] Chinese patents “CN201520394546 A Coke Oven Flue Gas Heat Backup System” and “CN202320079753 A Low-Temperature Coke Oven Flue Gas Desulfurization, Denitrification and Waste Heat Utilization System” propose to use a heat exchanger to exchange heat between air and coke oven flue gas after denitrification and waste heat boiler. The heated air is then sent into the coke oven chimney, thereby solving the problem of chimney heat backup.

[0005] Chinese patent "CN201610295380 Desulfurization and Denitrification Method and Apparatus for Using Coke Oven Flue Gas for Hot Backup of Coke Oven Chimney" proposes to use 160℃~180℃ coke oven flue gas discharged from waste heat boiler to heat the 60℃~80℃ coke oven flue gas discharged from desulfurization and denitrification absorption tower to 120℃~130℃ in the hot backup heat exchanger before sending it into the coke oven chimney, thus solving the hot backup problem of the chimney.

[0006] Chinese patent CN201620479180, "A Coke Oven Chimney Thermal Backup System Applicable to Wet Flue Gas Desulfurization and Denitrification Process," proposes to use a gas-gas heat exchanger to heat the clean coke oven flue gas after desulfurization and denitrification by utilizing the sensible heat of the high-temperature coke oven flue gas before desulfurization and denitrification. The heated clean coke oven flue gas is then sent into the coke oven chimney to achieve thermal backup of the coke oven chimney.

[0007] Chinese patent CN201620753101, "A system for low-temperature denitrification, wet desulfurization, dust removal, and ensuring chimney thermal standby," proposes that a certain amount of air is heated by using the sensible heat of the denitrified coke oven flue gas through an air heat exchanger, and then the heated air is sent into the coke oven chimney for thermal standby.

[0008] Chinese patent CN201621451587, "A device for thermal standby of coke oven chimneys," proposes that a certain amount of air is heated by using the sensible heat of the high-temperature coke oven flue gas before desulfurization through an air heat exchanger, and then the heated air is sent into the coke oven chimney for thermal standby of the coke oven chimney.

[0009] Chinese patent “CN201820466613 Coke Oven Chimney Non-Powered Thermal Standby System” proposes to open an air inlet at the base of the coke oven chimney, use steam to heat the air entering the coke oven chimney from the base, and then discharge the heated air through the coke oven chimney, so that the coke oven chimney is always in a thermal standby state.

[0010] The aforementioned technical measures, whether heating the desulfurized and denitrified flue gas to 100℃~130℃ or higher, or heating the air to 100℃~130℃ or higher, all require the installation of necessary heat exchange equipment. At the same time, a large amount of heat needs to be obtained from or additionally provided from the coke oven flue gas. The flue gas or air discharged from the coke oven chimney carries a large amount of waste heat and is discharged, resulting in insufficient energy recovery and utilization.

[0011] Chinese patent CN201621151226, "An Integrated Desulfurization, Denitrification, and Energy-Saving Purification System for Coke Oven Flue Gas," proposes equipping the coke oven flue gas induced draft fan with a coaxial internal combustion engine. In the event of an emergency power outage or circuit breaker trip, the coaxial internal combustion engine replaces the motor driving the induced draft fan, ensuring the normal operation of the desulfurization and denitrification system. This also avoids the pressure drop in the flue gas duct caused by the power outage. This method can eliminate the need for long-term hot standby of the coke oven chimney. However, in the event of an emergency power outage or circuit breaker trip, to avoid the pressure drop in the flue gas duct caused by the power outage, the internal combustion engine needs to be started. The internal combustion engine continuously consumes fuel to ensure the normal production of the coke oven. This solution increases the investment in the construction of the coke oven flue gas purification system, while also increasing new energy consumption and pollutant emissions. Summary of the Invention

[0012] The purpose of this invention is to provide a method for quickly starting up a coke oven chimney, overcoming the shortcomings of the prior art, and achieving a rapid restoration of the normal production state of the coke oven chimney without the need for continuous energy consumption for hot standby.

[0013] To achieve the above objectives, the present invention provides the following technical solution:

[0014] A method for rapidly restarting a coke oven chimney involves installing a flue gas ejector device inside the chimney. The device includes an ejector gas source, a pressure relief valve, an injection unit, and a connecting gas path. The ejector gas source is connected to the injection unit via the connecting gas path. When it is necessary to restore the pressure required for normal production within the coke oven chimney, the flue gas ejector device rapidly activates, generating upward force from the root of the chimney. This force guides the hot flue gas from the coke oven flue upwards through the chimney, creating a pressure difference between the inside and outside of the chimney required for normal coke oven production. This ensures the rapid restoration of the coke oven chimney to normal production status, achieving normal, safe, and stable production of the coke oven. The specific operating steps are as follows:

[0015] S1) Open the main flue gate of the coke oven and open the pressure relief valve set in the gas line connecting the ejector gas source and the injection unit;

[0016] S2) The high-pressure gas in the ejector gas source enters the injection unit inside the coke oven chimney along the connecting gas path, and is ejected out of the injection unit at high speed.

[0017] S3) The high-speed ejected airflow has an entraining effect in its vicinity and generates an entraining airflow, which drives the cold air in the coke oven chimney upward to the top outlet of the coke oven chimney.

[0018] S4) As the damper of the main flue of the coke oven opens, the high-temperature coke oven flue gas from the coke oven flue flows rapidly from the root of the coke oven chimney to the top outlet of the coke oven under the action of the injection unit and the thermal buoyancy of the flue gas itself.

[0019] S5) The flow of high-temperature coke oven flue gas in the coke oven chimney creates a pressure difference between the inside and outside of the coke oven chimney. This pressure difference promotes the formation of a stable high-temperature coke oven flue gas flow in the coke oven chimney, thereby enabling the coke oven heating system to operate normally and stably and avoiding any impact on coke oven production.

[0020] S6) After the coke oven chimney relies on the power of the coke oven flue gas itself to meet the normal and stable operation requirements of the heating system, close the pressure relief valve.

[0021] Furthermore, the ejector gas source is a container with a certain volume for storing high-pressure gas or a facility that can provide a stable gas source, and it is always maintained above a certain initial pressure during the period when the pressure relief valve is closed.

[0022] Furthermore, the pressure relief valve is a normally closed valve, which is opened in conjunction with the main gate of the coke oven flue, or opened independently after receiving an emergency opening command.

[0023] Furthermore, the outlet direction of the injection unit is the same as the outlet from the root to the top of the coke oven chimney, and the angle between the center line of the injection outlet and the center line of the coke oven chimney is between 10° and 80°.

[0024] Furthermore, the injection units are arranged in layers at different heights of the coke oven chimney, and the injection ports of each layer are connected to the ejector gas source through connecting gas passages; multiple injection units are evenly arranged around the circumference of the coke oven chimney.

[0025] Furthermore, normally closed valves are installed on the connecting gas lines of the layered injection units. After the normally closed valves on the connecting gas lines of the pressure relief valve and the highest layer injection unit are opened simultaneously, the injection units from the highest layer injection unit downwards are opened in sequence with a delay, forming an upward jet flow from top to bottom in the coke oven chimney, thereby rapidly ejecting the high-temperature coke oven flue gas from the main gate of the coke oven flue at the bottom of the coke oven chimney.

[0026] Furthermore, the coke oven chimney is equipped with an airflow ejection structure, which is a Venturi structure.

[0027] Furthermore, the initial pressure of the ejector gas source is not less than 0.2 MPa.

[0028] Furthermore, the initial pressure of the ejector gas source is above 0.6 MPa.

[0029] Furthermore, the gas storage capacity of the ejector gas source should ensure that the pressure inside the container is greater than 0.1 MPa 10 seconds after the pressure relief valve is opened.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1) Low construction cost: When the coke oven flue gas desulfurization and denitrification system fails or is shut down due to an emergency power outage, the flue gas ejector device generates external exhaust power within the coke oven chimney, guiding the high-temperature coke oven flue gas from the main flue gate to be quickly discharged through the coke oven chimney, thus rapidly restoring the coke oven chimney from a cold state to a state that ensures normal coke oven production. This invention does not require the installation of heat exchange equipment, nor does it require the consumption of fuel to maintain the normal operation of the coke oven desulfurization and denitrification system to ensure normal coke oven production, thereby avoiding an increase in the construction cost of the coke oven flue gas desulfurization and denitrification system.

[0032] 2) Simple maintenance and reliable operation. This invention only requires the existence of a high-pressure gas storage facility with a certain pressure and volume. It does not consume any energy under normal circumstances. The system is simple and convenient to maintain. When in use, it only consumes the limited high-pressure gas in the high-pressure gas storage facility. It does not require a continuous supply of high-pressure gas and operates at almost "zero" cost.

[0033] 3) This invention does not require the continuous discharge of hot flue gas or hot air with sufficient temperature through the coke oven chimney to maintain the chimney's thermal standby state. The temperature of the coke oven flue gas discharged through the coke oven chimney can be reduced to below 100°C or even lower, reducing the heat loss carried by the flue gas and enabling the ultimate recovery and utilization of waste heat energy from the coke oven flue gas. At the same time, it does not require additional energy to meet the thermal standby needs of the coke oven chimney, thereby further achieving energy conservation and consumption reduction. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the process flow of Embodiment 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of the connection between the coke oven chimney and the flue gas ejector in Embodiment 2 of the present invention;

[0036] Figure 3 yes Figure 2 Sectional view along line AA;

[0037] Figure 4 yes Figure 2 Sectional view along line BB;

[0038] Figure 5 This is a schematic diagram of the airflow ejection structure in Embodiment 3 of the present invention.

[0039] In the diagram: 1-Injector gas source, 2-Pressure relief valve, 3-Connecting gas path, 4-Injection unit, 5-Coke oven flue main gate, 6-Coke oven, 7-Desulfurization and denitrification system, 8-Waste heat recovery system, 9-Normally closed valve, 10-Injection port, 11-Coke oven chimney, 12-Airflow ejector structure. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the specific embodiments used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some embodiments of the present invention. For those skilled in the art, other specific embodiments can be obtained based on these specific embodiments without creative effort.

[0042] The components of the embodiments of the invention described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the specific embodiments is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0043] See Figure 1 This is a schematic diagram of the process flow of Embodiment 1 of the present invention. During normal production, the pressure required by the coke oven heating system is provided by the induced draft fan of the coke oven flue gas desulfurization and denitrification system 7. The coke oven flue gas undergoes pollutant reduction and waste heat recovery through the coke oven flue gas desulfurization and denitrification system 7 and the coke oven flue gas waste heat recovery system 8. The flue gas after desulfurization, denitrification, and waste heat recovery is then discharged through the coke oven chimney 11. When the coke oven flue gas desulfurization and denitrification system 7 malfunctions or an emergency power outage causes the system to shut down, the power generated by the flue gas ejector device installed in the coke oven chimney 11 guides the high-temperature coke oven flue gas from the main gate 5 of the coke oven flue to quickly pass through the coke oven chimney 11 for discharge, so that the coke oven chimney 11, which is in a cold state, can quickly return to a state that ensures the normal production of the coke oven 6.

[0044] The flue gas ejector device includes an ejector gas source 1, a pressure relief valve 2, a connecting gas line 3, and an injection unit 4. The ejector gas source 1 is a container with a certain volume for storing high-pressure gas or a facility that can provide a stable gas source. The ejector gas source 1 is connected to the injection unit 4 through the connecting gas line 2. The pressure relief valve 2 is a normally closed valve, which opens in conjunction with the main gate 5 of the coke oven flue, or opens independently upon receiving an emergency opening command. The outlet direction of the injection port 10 of the injection unit 4 is the same as the outlet from the root to the top of the coke oven chimney, and the angle α between the centerline of the outlet 10 and the centerline of the coke oven chimney is between 10° and 80°. The initial pressure in the ejector gas source 1 is not less than 0.2 MPa. The preferred value is above 0.6 MPa. The gas storage capacity of the ejector gas source 1 should ensure that the pressure in the container is greater than 0.1 MPa 10 seconds after the pressure relief valve is opened.

[0045] See Figure 2-4 This is a schematic diagram of the connection between the coke oven chimney and the flue gas ejector device in Embodiment 2 of the present invention. The injection units 4 are arranged in layers at different heights of the coke oven chimney 11. Each layer of injection port is connected to the ejector gas source 1 through the connecting gas passage 3. Multiple injection units 4 are evenly arranged around the circumference of the coke oven chimney. Normally closed valves 9 are respectively installed on the connecting gas passages of the layered injection units. After the pressure relief valve 2 and the normally closed valve on the connecting gas passage of the highest layer injection unit are opened simultaneously, the injection units from the highest layer injection unit downwards are opened in sequence with a delay, forming an upward ejector airflow continuously from top to bottom in the coke oven chimney, thereby rapidly ejecting and discharging the high-temperature coke oven flue gas from the main gate of the coke oven flue at the bottom of the coke oven chimney.

[0046] See Figure 5This is a schematic diagram of the airflow ejection structure in Embodiment 3 of the present invention. Based on Embodiments 1 and 2, in order to make the flue gas ejection device work better, an airflow ejection structure 12 is provided inside the coke oven chimney 11. The airflow ejection structure is of the Venturi type. When the high-pressure gas ejected from the injection unit 4 passes through the airflow ejection structure 12 set above it, it further generates an ejection effect around it, which quickly and efficiently guides the cold gas in the coke oven chimney 11 to the outlet of the coke oven chimney 11, thereby quickly restoring the normal flow of high-temperature coke oven flue gas in the coke oven chimney 11.

[0047] This invention discloses a method for rapidly restarting a coke oven chimney. The method involves installing a flue gas ejector device inside the chimney. When the pressure required for normal production within the chimney needs to be restored, the ejector device quickly activates, generating upward force from the chimney's base. This force guides hot flue gas from the coke oven flue upwards through the chimney, creating a pressure difference between the inside and outside of the chimney necessary for normal coke oven production. This rapidly restores the chimney to its normal operating state. The temperature of the coke oven flue gas discharged through the chimney 11 does not need to consider the thermal backup requirements of the chimney 11. Therefore, the waste heat energy of the coke oven flue gas can be recovered to the maximum extent through the coke oven flue gas waste heat recovery system 8. The specific operation steps are as follows:

[0048] S1) When the coke oven flue gas desulfurization and denitrification system 7 fails or an emergency power outage causes the system to shut down, the pressure required by the coke oven heating system can no longer be provided by the induced draft fan of the coke oven flue gas desulfurization and denitrification system 7. At this time, the main flue gate of the coke oven is opened, and the pressure relief valve set on the gas line connecting the induced gas source and the injection unit is opened.

[0049] S2) After the pressure relief valve 2 is opened, the high-pressure gas in the ejector gas source enters the injection unit inside the coke oven chimney along the connecting gas path and is ejected from the injection unit at high speed; the ejector gas source is always kept above a certain initial pressure.

[0050] S3) After the pressure relief valve 2 is opened, the high-pressure gas in the ejector gas source 1 enters the injection unit 4 inside the coke oven chimney 11 along the connecting gas path 3 under pressure. The high-speed ejected airflow is subjected to an ejection effect and generates an ejector airflow. The ejector airflow drives the cold air inside the coke oven chimney to flow upward toward the top outlet of the coke oven chimney.

[0051] S4) As the damper of the main flue of the coke oven opens, the high-temperature coke oven flue gas from the coke oven flue flows rapidly from the root of the coke oven chimney to the top outlet of the coke oven under the action of the injection unit and the thermal buoyancy of the flue gas itself.

[0052] S5) The flow of high-temperature coke oven flue gas in the coke oven chimney creates a pressure difference between the inside and outside of the coke oven chimney. This pressure difference promotes the formation of a stable high-temperature coke oven flue gas flow in the coke oven chimney, thereby enabling the coke oven heating system to operate normally and stably and avoiding any impact on coke oven production.

[0053] S6) After the coke oven chimney relies on the power of the coke oven flue gas itself to meet the normal and stable operation requirements of the heating system, close the pressure relief valve 2 and the operation ends.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for rapidly starting up a coke oven chimney, characterized in that, A flue gas ejector device is installed inside the coke oven chimney. This device includes an ejector gas source, a pressure relief valve, an injection unit, and a connecting gas path. The ejector gas source is connected to the injection unit via the connecting gas path. When it is necessary to restore the pressure required for normal production inside the coke oven chimney, the flue gas ejector device quickly activates, generating upward force from the root of the chimney. This guides the hot flue gas from the coke oven flue upwards and out through the chimney, thereby creating the pressure difference required for normal coke oven production inside and outside the chimney. This ensures the rapid restoration of the coke oven chimney to normal production status, achieving normal, safe, and stable production of the coke oven. The specific operating steps are as follows: S1) Open the damper of the coke oven main flue and open the pressure relief valve set in the gas line connecting the ejector gas source and the injection unit; S2) The high-pressure gas in the ejector gas source enters the injection unit inside the coke oven chimney along the connecting gas path, and is ejected from the injection unit at high speed. S3) The high-speed ejected airflow has an entraining effect in its vicinity and generates an entraining airflow, which drives the cold air in the coke oven chimney upward toward the top outlet of the coke oven chimney. S4) As the damper of the main flue of the coke oven opens, the high-temperature coke oven flue gas from the coke oven flue flows rapidly from the root of the coke oven chimney to the top outlet of the coke oven under the action of the injection unit and the thermal buoyancy of the flue gas itself. S5) The flow of high-temperature coke oven flue gas in the coke oven chimney creates a pressure difference between the inside and outside of the coke oven chimney. This pressure difference promotes the formation of a stable high-temperature coke oven flue gas flow in the coke oven chimney, thereby enabling the coke oven heating system to operate normally and stably and avoiding any impact on coke oven production. S6) After the coke oven chimney relies on the power of the coke oven flue gas itself to meet the normal and stable operation requirements of the heating system, close the pressure relief valve; The ejector gas source is a container with a certain volume for storing high-pressure gas or a facility that can provide a stable gas source, and it is always maintained above a certain initial pressure during the period when the pressure relief valve is closed; the gas storage capacity of the ejector gas source should ensure that the pressure in the container is greater than 0.1 MPa after the pressure relief valve is opened for 10 seconds. The injection units are arranged in layers at different heights of the coke oven chimney, and the injection ports of each layer are connected to the ejector gas source through connecting gas passages; multiple injection units are evenly arranged around the circumference of the coke oven chimney. Normally closed valves are installed on the connecting gas lines of the layered injection units. After the normally closed valves on the connecting gas lines of the pressure relief valve and the highest layer injection unit are opened simultaneously, the injection units from the highest layer injection unit downwards are opened in sequence with a delay, forming an upward jet flow from top to bottom in the coke oven chimney, thereby rapidly ejecting the high-temperature coke oven flue gas from the main gate of the coke oven flue at the bottom of the coke oven chimney.

2. The method for rapidly starting up a coke oven chimney according to claim 1, characterized in that, The pressure relief valve is a normally closed valve that opens in conjunction with the main gate of the coke oven flue, or opens independently upon receiving an emergency opening command.

3. The method for rapidly starting up a coke oven chimney according to claim 1, characterized in that, The direction of the injection outlet of the injection unit is the same as that from the root of the coke oven chimney to the top of the coke oven chimney, and the angle between the center line of the injection outlet and the center line of the coke oven chimney is between 10° and 80°.

4. The method for rapidly starting up a coke oven chimney according to claim 1, characterized in that, The coke oven chimney is equipped with an airflow ejection structure, which is a Venturi structure.

5. The method for rapidly starting up a coke oven chimney according to claim 1, characterized in that, The initial pressure of the ejector gas source is not less than 0.2 MPa.

6. The method for rapidly starting up a coke oven chimney according to claim 1, characterized in that, The initial pressure of the ejector gas source is above 0.6 MPa.

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