阅读说明：本技术 生产针状焦用轻重相油加热和尾气焚烧一体式炉及控制方法 (Light-heavy phase oil heating and tail gas burning integrated furnace for producing needle coke and control method ) 是由 任铁良 张功多 谢国威 李岩 李志红 李宝东 于 2019-09-12 设计创作，主要内容包括：一种生产针状焦用轻重相油加热和尾气焚烧一体式炉及控制方法,一体式炉包括炉体、烧嘴和油管；烧嘴包括主烧嘴和分火嘴,油管包括轻相油管和重相油管。炉体由中间的圆柱体、上部的圆台体和下部的圆锥体构成,主烧嘴位于下部圆锥体的底部锥口处,分火嘴位于圆柱体中部侧壁开口处。重相油管悬挂于炉体的圆柱体内的下部,轻相油管悬挂于炉体的圆柱体内的上部和上部的圆台体内。集成了现有煤系针状焦轻相油加热炉、重相油加热炉、尾气焚烧炉,将原有的三炉合成为为一体式炉,占地面积和空间不仅大为减少、总体系统燃气管路大为简化,同时为炉子设计的控制系统方法不仅快速安全、实现一体式炉自动点火和灭火,而且现场可以实现无人操作。(A light-heavy phase oil heating and tail gas burning integrated furnace for producing needle coke and a control method thereof, wherein the integrated furnace comprises a furnace body, a burner and an oil pipe; the burner comprises a main burner and a branch burner, and the oil pipe comprises a light phase oil pipe and a heavy phase oil pipe. The furnace body comprises cylinder in the middle of, the round platform body on upper portion and the cone of lower part, and main nozzle is located the bottom cone department of lower part cone, and the branch fire mouth is located cylinder middle part lateral wall opening part. The heavy phase oil pipe is suspended at the lower part in the cylinder of the furnace body, and the light phase oil pipe is suspended at the upper part in the cylinder of the furnace body and in the circular truncated cone at the upper part. The existing coal-based needle coke light-phase oil heating furnace, the existing heavy-phase oil heating furnace and the existing tail gas incinerator are integrated, the original three furnaces are combined into an integrated furnace, the occupied area and the space are greatly reduced, the gas pipeline of the overall system is greatly simplified, and meanwhile, a control system method designed for the furnaces is quick and safe, realizes automatic ignition and fire extinguishing of the integrated furnace, and can realize unmanned operation on site.)

1. A light-heavy phase oil heating and tail gas burning integrated furnace for producing needle coke is characterized in that the integrated furnace comprises a furnace body, a burner and an oil pipe; the burner comprises a main burner and a branch burner, and the oil pipe comprises a light phase oil pipe and a heavy phase oil pipe;

the furnace body consists of a middle cylinder, an upper circular table body and a lower cone, the top of the upper circular table body is connected with the flue, the main burner is positioned at the bottom cone of the lower cone, and the fire distributing nozzle is positioned at the opening of the side wall of the middle part of the cylinder;

the heavy phase oil pipe is suspended at the lower part in the cylinder of the furnace body and spirally spirals along the inner wall of the furnace, the upper part is a heavy phase oil inlet, and the lower part is a heavy phase oil outlet which are both positioned at the opening of the side wall of the cylinder;

the light phase oil pipe is suspended in the upper part and the circular truncated cone body at the upper part in the cylinder body of the furnace body and spirally spirals along the inner wall of the furnace, the light phase oil inlet is positioned at the opening of the side wall of the circular truncated cone body at the upper part, and the light phase oil outlet is positioned at the opening of the side wall of the cylinder body.

2. The integrated furnace for heating light and heavy phase oil and incinerating tail gas for producing needle coke according to claim 1, wherein 3 tail gas inlets are uniformly arranged along the circumference in the middle of a cone at the bottom of the furnace body, and the 3 tail gas inlets mutually form a 120-degree central angle; the fire distribution nozzles comprise 3 fire distribution nozzles which are uniformly arranged along the circumference in the middle of a cylinder of the furnace body, form a 120-degree central angle with each other, form a 60-degree central angle with the tail gas inlet and are arranged in a staggered manner with the tail gas inlet.

3. The integrated furnace for heating light and heavy phase oil and burning tail gas for producing needle coke as claimed in claim 1, wherein the bottom cone of the lower cone of the furnace body is provided with a flat bottom portion, the main burner is located at the opening in the middle of the flat bottom portion, and the flat bottom portion is constructed by magnesia carbon bricks.

4. The integrated furnace for heating light and heavy phase oil and incinerating tail gas for producing needle coke according to claim 1 or 2, characterized in that the lower cone and the middle cylinder of the furnace body are built by magnesia carbon bricks except for a tail gas inlet and a fire distributing nozzle, and the furnace linings of the other furnace bodies are built by high-alumina bricks; the round table body at the upper part of the furnace body and the upper flue are separately knotted by refractory materials.

5. The control system of the integrated furnace for heating light and heavy phase oil and incinerating tail gas for producing needle coke in claim 1 is characterized by comprising a heavy phase oil outlet temperature control loop TC1, a light phase oil outlet temperature control loop TC2, a hearth pressure control loop PC, a flue gas oxygen content control loop AC, an automatic ignition control loop BC and an SIS control loop;

the auto-ignition control circuit BC includes: the device comprises an ignition transformer BE0 arranged in a long open fire igniter, a long open fire flame detector B0 arranged in the long open fire igniter, a main fire nozzle flame detector B1, a hearth pressure adjusting flap valve PV1, a main fire nozzle combustion air adjusting valve AV1, main fire nozzle gas quick cut-off valves V1 and V2, long open fire quick cut-off valves V3 and V4, a main fire nozzle gas flow pneumatic adjusting valve FV1, a gas flow adjusting valve FV2 of a branch fire nozzle, a furnace combustible gas detector A2, a tail gas pressure detector P5, a tail gas quick cut-off valve V5 and a nitrogen purging valve V6, wherein the devices are all connected with an I/O port of a control system.

6. The auto-ignition control method of the auto-ignition control circuit BC of the control system of the integrated furnace for heating light and heavy phase oil and incinerating tail gas for producing needle coke of claim 5, wherein the control system controls the execution elements to act in sequence according to the parameter change of the detection elements, and the method comprises the following steps:

101, before automatic ignition, judging whether the pressure P1 of a gas main pipe is higher than a safe pressure threshold value, if so, alarming, and if so, opening a hearth pressure pneumatic flap valve PV1 to full open and a combustion air pneumatic regulating valve AV1 to full open;

step 102, judging whether the content A2 of combustible gas in the furnace is lower than the ignition safety content threshold value, if so, opening a nitrogen pneumatic purge valve V6, blowing nitrogen into the furnace, and displacing the gas in the furnace until the gas in the furnace reaches below the safety threshold value;

103, opening 2 pneumatic quick cut-off valves V3 and V4 for the long open fire, and switching on the ignition transformer BE for the long open fire to ignite the long open fire;

104, after detecting that flame of the long open fire exists in the B0, opening 2 main fire nozzle pneumatic quick cut-off valves V1 and V2, setting the opening of a main fire nozzle gas pneumatic regulating valve FV1 at 15-25%,

105, detecting whether main flames exist or not by a main flame nozzle flame detection B1, and setting the opening of a main flame nozzle gas pneumatic regulating valve FV1 to be 75-85% after the main flames are detected; the opening degree of a gas pneumatic regulating valve FV2 of 3 fire distributing nozzles is set to be 15-25%;

106, judging whether the pressure P5 of the tail gas is higher than a safety pressure threshold value, and if so, opening a tail gas pneumatic quick cut-off valve V5; this concludes the ignition sequence.

7. The automatic fire extinguishing control method for the automatic ignition control loop of the control system of the integrated furnace for light and heavy phase oil heating and tail gas incineration for needle coke production, which is characterized by comprising the following sequential steps:

step 201, closing 2 main fire nozzle pneumatic quick cut-off valves V1 and V2, closing 2 long open fire pneumatic quick cut-off valves V1 and V2, and closing a tail gas pneumatic quick cut-off valve V5;

202, setting the openness of a main burner gas pneumatic regulating valve FV1 to be 0%, and setting the openness of 3 distributor gas pneumatic regulating valves FV2 to be 0%;

step 203, opening a hearth pressure pneumatic flap valve PV1 to full open;

step 204, setting the opening of a combustion air regulating valve AV1 to be 0%;

step 205, judging whether the combustible gas A2 in the furnace reaches below a threshold value;

step 204, if the combustible gas A2 in the furnace is not below the threshold value, opening a nitrogen pneumatic purge valve V6, blowing nitrogen into the furnace, and replacing the gas in the furnace; until the gas in the furnace reaches below a safe threshold;

and step 205, when the combustible gas A2 in the furnace reaches the threshold value or below, ending the fire extinguishing program.

8. The method for controlling safe shutdown of SIS safety loop of control system of light and heavy phase oil heating and tail gas burning integrated furnace for producing needle coke of claim 5, characterized in that a gas flame arrester is provided before the gas main pipeline and gas enter into the furnace, the main gas pipeline between the gas flame arrester and the main burner is provided with a main burner gas regulating valve FV1, a main burner gas regulating valve FV2, 2 main burner gas pneumatic quick cut-off valves V1 and V2 and a pressure transmitter P2 are provided on the gas main pipeline, 2 long open fire gas pneumatic quick cut-off valves V3 and V4 and a pressure transmitter P3 are provided on the long open fire gas pipeline, a gas pressure transmitter P1 is provided at the gas outlet of the gas flame arrester, a combustion air regulating valve AV1 is provided on the main burner combustion air pipeline, a nitrogen purge valve V6 is provided on the nitrogen purge pipeline, a tail gas flame arrester is provided on the tail gas main pipeline, a tail gas pneumatic quick cut-off valve V5 is arranged on a tail gas inlet main pipeline from the tail gas flame arrester;

the safe parking control comprises the following steps:

301, when gas pressure P1, P2 and P3 are low and 3 is selected to 2, or main flame detection B1 is used for fire extinguishing or an emergency furnace shutdown button is pressed down, the solenoid valves of the pneumatic quick cut-off valves V1 and V2 lose power to cut off gas of a main burner, and the solenoid valves of the pneumatic quick cut-off valves V3 and V4 lose power to cut off gas of long-time open fire;

302, cutting off the tail gas when the electromagnetic valve V5 of the pneumatic quick cut-off valve is powered off;

and step 303, turning on the solenoid valve of the pneumatic valve V6 to purge nitrogen when the solenoid valve is electrified, and delaying the fixed purging time to lose power.

Technical Field

The invention relates to the technical field of heating furnaces for producing light and heavy phase oil from coke, in particular to a light and heavy phase oil heating and tail gas burning integrated furnace for producing needle coke and a control method.

Background

The needle coke is a raw material for producing various high-power and ultrahigh-power electrodes, light-phase oil and heavy-phase oil separated from coal tar are required to be heated to the required temperature of the process in the process of raw material pretreatment in the production process of the needle coke, the conventional raw material pretreatment heating process flow is that the light-phase oil is heated by a tubular light-phase heating furnace, the heavy-phase oil is heated by a tubular heavy-phase heating furnace, and noncondensable gas (combustible tail gas) generated by the pretreatment of the coal tar is combusted by a tail gas incinerator and then is exhausted. The existing technological process is that a light phase heating furnace is provided with 4 sets of burners, a heavy phase heating furnace is provided with 3 sets of burners, a tail gas incinerator is provided with 1 set of burners, each set of burner comprises an ignition system and a flame detection system, the total number of the 3 burners is 8 burners, the flame detection systems and 8 sets of flame detection points, the ignition is complex, the investment of the control system is large, and the heat energy of tail gas incineration is abandoned and cannot be utilized.

Aiming at the defects of the needle coke raw material pretreatment raw oil heating process, the invention provides the integrated furnace and the control method thereof for solving the heat energy utilization of needle coke raw material pretreatment light and heavy phase oil heating and tail gas incineration.

Disclosure of Invention

In order to solve the technical problems in the background art, the invention provides a light-heavy phase oil heating and tail gas incineration integrated furnace for producing needle coke and a control method thereof.

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

a light-heavy phase oil heating and tail gas burning integrated furnace for producing needle coke comprises a furnace body, a burner and an oil pipe; the burner comprises a main burner and a branch burner, and the oil pipe comprises a light phase oil pipe and a heavy phase oil pipe.

The furnace body comprises cylinder, the round platform body of upper portion and the cone of lower part in the middle of by, the round platform body top on upper portion links to each other with the flue, and main nozzle is located the bottom cone department of lower part cone, and the branch flame nozzle is located cylinder middle part lateral wall opening part.

The heavy phase oil pipe is suspended at the lower part in the cylinder of the furnace body, spirally spirals along the inner wall of the furnace, the upper part is a heavy phase oil inlet, and the lower part is a heavy phase oil outlet which are both positioned at the opening of the side wall of the cylinder.

The light phase oil pipe is suspended in the upper part and the circular truncated cone body at the upper part in the cylinder body of the furnace body and spirally spirals along the inner wall of the furnace, the light phase oil inlet is positioned at the opening of the side wall of the circular truncated cone body at the upper part, and the light phase oil outlet is positioned at the opening of the side wall of the cylinder body.

3 tail gas inlets are uniformly arranged in the middle of a cone at the bottom of the furnace body along the circumference, and the 3 tail gas inlets mutually form a 120-degree central angle; the fire distribution nozzles comprise 3 fire distribution nozzles which are uniformly arranged along the circumference in the middle of a cylinder of the furnace body, form a 120-degree central angle with each other, form a 60-degree central angle with the tail gas inlet and are arranged in a staggered manner with the tail gas inlet.

A flat bottom part is arranged at the bottom cone opening of the lower cone of the furnace body, the main burner is positioned at the opening in the middle of the flat bottom part, and the flat bottom part is built by magnesia carbon bricks.

In the lower cone and the middle cylinder of the furnace body, except for a tail gas inlet and a fire separating nozzle, magnesia carbon bricks are used for building, and furnace linings of other furnace bodies are built by high-alumina bricks; the round table body at the upper part of the furnace body and the upper flue are separately knotted by refractory materials.

A control system of a light-heavy phase oil heating and tail gas burning integrated furnace for producing needle coke comprises a heavy phase oil outlet temperature control loop TC1, a light phase oil outlet temperature control loop TC2, a hearth pressure control loop PC, a smoke oxygen content control loop AC, an automatic ignition control loop BC and an SIS control loop.

The auto-ignition control circuit BC includes: the device comprises an ignition transformer BE0 arranged in a long open fire igniter, a long open fire flame detector B0 arranged in the long open fire igniter, a main fire nozzle flame detector B1, a hearth pressure adjusting flap valve PV1, a main fire nozzle combustion air adjusting valve AV1, main fire nozzle gas quick cut-off valves V1 and V2, long open fire quick cut-off valves V3 and V4, a main fire nozzle gas flow pneumatic adjusting valve FV1, a gas flow adjusting valve FV2 of a branch fire nozzle, a furnace combustible gas detector A2, a tail gas pressure detector P5, a tail gas quick cut-off valve V5 and a nitrogen purging valve V6, wherein the devices are all connected with an I/O port of a control system.

According to the automatic ignition control method of the automatic ignition control loop, the control system controls the execution elements to act in sequence according to the parameter change of the detection elements, and the method specifically comprises the following steps:

101, before automatic ignition, judging whether the pressure P1 of a gas main pipe is higher than a safe pressure threshold value, if so, alarming, and if so, opening a hearth pressure pneumatic flap valve PV1 to full open and a combustion air pneumatic regulating valve AV1 to full open;

step 102, judging whether the content A2 of combustible gas in the furnace is lower than the ignition safety content threshold value, if so, opening a nitrogen pneumatic purge valve V6, blowing nitrogen into the furnace, and displacing the gas in the furnace until the gas in the furnace reaches below the safety threshold value;

103, opening 2 pneumatic quick cut-off valves V3 and V4 for the long open fire, and switching on the ignition transformer BE for the long open fire to ignite the long open fire;

104, after detecting that flame of the long open fire exists in the B0, opening 2 main fire nozzle pneumatic quick cut-off valves V1 and V2, setting the opening of a main fire nozzle gas pneumatic regulating valve FV1 at 15-25%,

105, detecting whether main flames exist or not by using a main flame nozzle flame detection B1, and setting the opening of a main flame nozzle gas pneumatic regulating valve FV1 to be 80 +/-5% after the main flames are detected; the opening degree of a gas pneumatic regulating valve FV2 of 3 fire distributing nozzles is set to be 15-25%;

106, judging whether the pressure P5 of the tail gas is higher than a safety pressure threshold value, and if so, opening a tail gas pneumatic quick cut-off valve V5; this concludes the ignition sequence.

The automatic fire extinguishing control method of the automatic ignition control loop comprises the following sequential steps:

step 201, closing 2 main fire nozzle pneumatic quick cut-off valves V1 and V2, closing 2 long open fire pneumatic quick cut-off valves V1 and V2, and closing a tail gas pneumatic quick cut-off valve V5;

202, setting the openness of a main burner gas pneumatic regulating valve FV1 to be 0%, and setting the openness of 3 distributor gas pneumatic regulating valves FV2 to be 0%;

step 203, opening a hearth pressure pneumatic flap valve PV1 to full open;

step 204, setting the opening of a combustion air regulating valve AV1 to be 0%;

step 205, judging whether the combustible gas A2 in the furnace reaches below a threshold value;

step 204, if the combustible gas A2 in the furnace is not below the threshold value, opening a nitrogen pneumatic purge valve V6, blowing nitrogen into the furnace, and replacing the gas in the furnace; until the gas in the furnace reaches below a safe threshold;

and step 205, when the combustible gas A2 in the furnace reaches the threshold value or below, ending the fire extinguishing program.

The safe shutdown control method of the SIS safety loop of the integrated furnace for heating light and heavy phase oil and incinerating tail gas for producing needle coke, a gas flame arrester is arranged before a gas main pipeline and gas enter a furnace, a main fire nozzle gas regulating valve FV1 and a main fire nozzle gas regulating valve FV2 are arranged on a main gas pipeline between the gas flame arrester and a main fire nozzle, 2 main fire nozzle gas pneumatic quick cut-off valves V1 and V2 and a pressure transmitter P2 are arranged on a gas main line, 2 long open fire gas pneumatic quick cut-off valves V3 and V4 and a pressure transmitter P3 are arranged on a long open fire gas line, a gas pressure transmitter P1 is arranged at a gas outlet of a gas flame arrester, a combustion air regulating valve AV1 is arranged on a main fire nozzle combustion air pipeline, a nitrogen purging valve V6 is arranged on the nitrogen purging pipeline, a tail gas flame arrester is arranged on a tail gas main line, and a tail gas pneumatic quick cut-off valve V5 is arranged from the tail gas flame arrester to a tail gas inlet main line; the method comprises the following steps:

301, when gas pressure P1, P2 and P3 are low and 3 is selected to 2, or main flame detection B1 is used for fire extinguishing or an emergency furnace shutdown button is pressed down, the solenoid valves of the pneumatic quick cut-off valves V1 and V2 lose power to cut off gas of a main burner, and the solenoid valves of the pneumatic quick cut-off valves V3 and V4 lose power to cut off gas of long-time open fire;

302, cutting off the tail gas when the electromagnetic valve V5 of the pneumatic quick cut-off valve is powered off;

and step 303, turning on the solenoid valve of the pneumatic valve V6 to purge nitrogen when the solenoid valve is electrified, and delaying the fixed purging time to lose power.

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

1) the invention integrates the existing coal-based needle coke light-phase oil heating furnace, heavy-phase oil heating furnace and tail gas incinerator, and integrates the original three furnaces into an integrated furnace, so that the occupied area and space are greatly reduced, the original 3 main gas burner burners of the furnace are reduced from 8 sets to 1 set of main burner burners of the integrated furnace, the gas pipeline of the overall system is greatly simplified, the overall construction cost of the furnace is greatly reduced, and the maintenance workload of the furnace is greatly reduced;

2) the main burner is arranged at the bottom of the furnace body, the fire distribution nozzle is arranged in the middle of the furnace body, and the fire distribution nozzle effectively supplements heating on the upper part of the furnace body;

3) the arrangement of the tail gas inlet and the fire distributing nozzle ensures that the burning heat energy can be fully utilized, the comprehensive consumption of fuel gas can be reduced, the heat pollution to the environment is reduced, and the production cost of the coal-based needle coke is reduced;

4) through installing an online combustible gas detecting instrument in the integral furnace at the bottom of the integral furnace, the integral furnace completely realizes safe automatic ignition and safe automatic fire return. The problem that whether a dangerous source exceeds the standard or not is detected by a handheld combustible gas detector before an existing coal-series needle coke light-phase oil heating furnace, a heavy-phase oil heating furnace and a tail gas incinerator are ignited can be solved, automatic ignition and fire extinguishing of the integrated furnace are rapidly and safely achieved, and unmanned operation can be achieved on site.

Drawings

FIG. 1 is an overall structure view of an integrated furnace for heating light and heavy phase oil and burning tail gas for producing needle coke according to the present invention;

FIG. 2 is a diagram of a control system for the integrated furnace for light and heavy phase oil heating and tail gas incineration for needle coke production according to the present invention;

FIG. 3 is a flow chart of the auto-ignition circuit control method of the integrated furnace for light and heavy phase oil heating and tail gas incineration for needle coke production according to the present invention;

FIG. 4 is a flow chart of the control method of the automatic fire extinguishing loop of the integrated furnace for heating light and heavy phase oil and burning tail gas for producing needle coke according to the present invention;

FIG. 5 is a flow chart of the SIS safety loop control method of the integrated furnace for heating light and heavy phase oil and burning tail gas for producing needle coke according to the present invention.

Wherein: 1-cone part at the bottom of the furnace body 2-cylinder part at the middle of the furnace body 3-round table part at the upper part of the furnace body 4-flue 5-main burner 6-fire distribution nozzle 7-tail gas inlet 8-heavy phase oil pipe 9-light phase oil pipe 10-heavy phase oil inlet 11-heavy phase oil outlet 12-light phase oil inlet 13-light phase oil outlet 14-flat bottom part 15-flue opening flap valve 16-ever open fire gas inlet 17-steam fire extinguishing port 18-nitrogen blowing port 51-main burner gas inlet 52-main burner air inlet 61-fire distribution nozzle gas inlet 62-fire distribution nozzle air inlet.

Detailed Description

The following detailed description of the present invention will be made with reference to the accompanying drawings.

As shown in fig. 1, the integrated furnace for heating light and heavy phase oil and burning tail gas for producing needle coke comprises a furnace body, a burner and an oil pipe; the burner comprises a main burner 5 and a fire distribution nozzle 6, and the oil pipe comprises a light phase oil pipe 9 and a heavy phase oil pipe 8.

The furnace body comprises cylinder 2, the round platform body 3 on upper portion and the cone 1 of lower part in the middle of, the round platform body 3 top on upper portion links to each other with the flue 4 of cylinder, main nozzle 5 is located the bottom cone department of lower part cone 1, branch burner 6 is located the lateral wall opening part in the middle part of cylinder 2.

The heavy phase oil pipe 8 is suspended at the lower part in the cylinder 2 of the furnace body and spirally spirals along the inner wall of the furnace, the upper part is a heavy phase oil inlet 10, and the lower part is a heavy phase oil outlet 11 which are both positioned at the opening of the side wall of the cylinder 2;

the light phase oil pipe 9 is suspended in the upper part and the upper part of the round table body 3 in the cylinder 2 of the furnace body, spirally spirals along the inner wall of the furnace, the light phase oil inlet 12 is positioned at the opening of the side wall of the upper round table body 3, and the outlet 13 is positioned at the opening of the side wall of the cylinder 2.

3 tail gas inlets 7 are uniformly arranged in the middle of a cone 1 at the bottom of the furnace body along the circumference, and the 3 tail gas inlets 7 mutually form a 120-degree central angle; the fire distribution nozzles 6 comprise 3 fire distribution nozzles which are uniformly arranged along the circumference in the middle of the cylinder 2 of the furnace body, form a 120-degree central angle with each other, form a 60-degree central angle with the tail gas inlet 7 and are arranged in a staggered manner with the tail gas inlet 7.

A flat bottom part 14 is arranged at the bottom cone opening of the lower cone 1 of the furnace body, the main burner 5 is positioned at the opening in the middle of the flat bottom part 14, and the flat bottom part 14 is built by high-quality magnesia carbon bricks.

In the lower cone 1 and the middle cylinder 2 of the furnace body, except for the position of a tail gas inlet 7 and the position of a fire separating nozzle 6, the furnace linings of the other furnace bodies are built by high-alumina bricks; the round table body 3 and the upper flue 4 on the upper part of the furnace body are separately knotted by refractory materials.

And a flue opening flap valve 15 is arranged in the flue 4.

Besides the main burner 5, a flat bottom part 14 at the center of the bottommost cone opening of the furnace body cone 1 is also provided with a steam fire extinguishing opening 17, a nitrogen purging opening 18 and an open flame gas inlet 16 for igniting the main burner, wherein the steam fire extinguishing opening 17, the nitrogen purging opening 18 and the open flame gas inlet 16 are arranged close to the main burner 5, and the flame gas inlet 16 is close to the main burner 10.

The main burner 5 is respectively provided with a gas inlet 51 and an air inlet 52; the branch nozzles 6 have a gas inlet 61 and a natural suction air inlet 62, respectively.

As shown in fig. 2, the automatic control system of the integrated furnace for heating light and heavy phase oil and burning tail gas for producing needle coke. A flue outlet front pressure transmitter P4, a flue gas oxygen content sensor (zirconia) A1 and a flue gas temperature sensor (thermocouple) T9 are arranged at the flue, a hearth upper temperature sensor (thermocouple) T8 is arranged at the top of the furnace, a flue front (hearth) pressure adjusting pneumatic flap valve PV1 is arranged at the flue, a hearth middle temperature sensor (thermocouple) T7 is arranged at the middle of the furnace, a hearth lower temperature sensor (thermocouple) T6 is arranged at the bottom of the furnace, a combustible gas detection sensor (electrochemistry) A2 is arranged at the bottom of the furnace, a flame detector (spectrum) B1 is arranged in a main burner nozzle, an inlet temperature sensor (thermal resistor) T4, a pressure transmitter P7 and a flow transmitter (differential pressure) F4 are arranged at a heavy phase oil outlet, an outlet temperature sensor (thermal resistor) T5 is arranged at a heavy phase oil inlet (heavy phase oil frequency conversion pump FP1 outlet), an inlet temperature sensor (thermal resistor) T2, a flue gas temperature sensor (thermal resistor) T2, Pressure transmitter P6, flow transmitter (differential pressure) F3, light phase oil outlet install export temperature sensor (thermal resistance) T3.

A gas flame arrester is arranged before a gas main pipeline and gas enter a furnace, a gas flow transmitter (differential pressure) F1 and a main fire nozzle gas regulating valve FV1 are arranged on the main gas pipeline between the gas flame arrester and a main fire nozzle, a gas flow transmitter (differential pressure) F2 and a main fire nozzle gas regulating valve FV2 are arranged on the branch gas pipeline between the gas flame arrester and the branch fire nozzle, 2 main fire nozzle gas pneumatic quick cut-off valves V1 and V2 (redundancy) and a pressure transmitter P2 are arranged on the gas main pipeline, 2 long open fire gas pneumatic quick cut-off valves V3 and V4 (redundancy) and a pressure transmitter P3 are arranged on the gas main pipeline, a gas temperature sensor (thermal resistance) T1 and a pressure transmitter P1 are arranged at a gas outlet of the gas flame arrester, an air regulating valve AV1 is arranged on the main fire nozzle combustion-supporting air pipeline, a nitrogen purging valve V6 is arranged on the nitrogen purging combustion-supporting pipeline, and a tail gas flame arrester is arranged on the main pipeline, and a tail gas pneumatic quick cut-off valve V5 and a pressure transmitter P5 are arranged on a tail gas flame arrester to tail gas inlet main pipeline.

The long open fire igniter is vertically arranged close to the main burner of the fuel gas, and adopts a built-in flame detector (ion detection) B0 and an ignition transformer BE.

The invention discloses an integrated furnace for heating light-phase and heavy-phase oil and incinerating tail gas for producing needle coke, which aims to meet the production requirements that the flow rate of the light-phase oil and the temperature of an outlet are kept at constant target values, the flow rate of the heavy-phase oil and the temperature of the outlet are kept at constant target values, the pressure of a hearth is kept at a constant value, and the oxygen content of smoke is kept constant.

In order to realize the production target, the automatic control system of the light-heavy phase oil heating and tail gas burning integrated furnace for producing the needle coke is constructed by a control system consisting of 6 conventional control loops, 1 automatic ignition control loop and 1 Safety Instrument System (SIS) cut-off loop. See the dashed connection loop in fig. 2.

When the parameters in any one of the 6 control loops are disturbed, other loops can quickly follow the disturbance at the same time, and the new balance can be stably achieved.

(1) Heavy phase oil outlet temperature control loop TC1

The TC1 control circuit is composed of a heavy phase oil outlet temperature detection T5, a main burner gas flow detection F1 and a main burner gas regulating valve FV 1.

FV1 and F1 form an inner loop (primary) PID control (positive action), F1 and T5 form an outer loop (secondary) PID control (positive action), and the primary and secondary form FV1-F1-T5 cascade control.

(2) Light phase oil outlet temperature control loop TC2

The TC2 control circuit is composed of a light phase oil outlet temperature detection T3, a fuel gas flow detection F2 of a fire distribution nozzle (3), and a fuel gas regulating valve FV2 of the fire distribution nozzle.

FV2 and F2 form an inner loop (primary) PID control (positive action), F2 and T3 form an outer loop (secondary) PID control (positive action), and the primary and secondary form FV2-F2-T3 cascade control.

(3) Hearth pressure control loop PC

The PC control loop is composed of a flue outlet front pressure detection P4 and a flue gas pressure adjusting flap valve PV 1.

PV1 and P4 constitute a simple PID control (reaction).

(4) Flue gas oxygen content control loop AC

The AC control loop is composed of a flue outlet oxygen content detection A1 and a main burner combustion air regulating valve AV 1.

AV1 and a1 constitute simple PID controls (positive action).

(5) Heavy phase oil flow control loop FC1

The FC1 control loop is composed of a heavy phase oil pump outlet flow detection F4 and a heavy phase oil variable frequency pump FP 1.

FP1 and F4 constitute a simple PID control (positive action).

(6) Light phase oil flow control loop FC2

The FC2 control loop is composed of a light phase oil pump outlet flow detection F3 and a light phase oil variable frequency pump FP 2.

FP2 and F3 constitute a simple PID control (positive action).

(1) Typical control parameter settings employed in the control loop of (6) are as follows:

1) the temperature of the light phase oil outlet is controlled to be 290-300 ℃,

2) and controlling the outlet temperature of the heavy phase oil to be 330-340 ℃.

3) And controlling the oxygen content of the outlet flue gas to be 3-4%.

4) The pressure in front of the flue outlet (hearth) is controlled to be-100 to-110 Pa.

Typical production scale of 4 ten thousand tons/year needle coke plant, 5) light phase oil flow control of 20-22t/h, 6) heavy phase oil flow control of 8-10 t/h.

The parameters of the light and heavy phase oil for producing the needle coke and the light and heavy phase oil for entering the furnace by the tail gas incineration integrated furnace are as follows:

the temperature of the light-phase oil entering the furnace is 160 ℃, and the outlet pressure of the light-phase oil pump is 1.6 MPa; the temperature of the heavy phase oil entering the furnace is 190 ℃, and the outlet pressure of the heavy phase oil pump is 1.6 MPa.

(7) Auto-ignition control loop BC

The BC automatic ignition control circuit is composed of an ignition transformer BE0 arranged in a pilot light igniter, pilot light flame detection B0 arranged in the igniter, main burner flame detection B1, a hearth pressure adjusting flap valve PV1, a main burner combustion air adjusting valve AV1, main burner gas quick cut-off valves V1 and V2, pilot light quick cut-off valves V3 and V4, a main burner gas flow pneumatic adjusting valve FV1, fire distributing nozzle (3) gas flow adjusting valves FV2, furnace combustible gas detection A2, tail gas pressure detection P5, a tail gas quick cut-off valve V5 and a nitrogen purging valve V6, the devices are all connected with an IO port of a control system, and the control system is a PLC system, a DCS system or an SIS system.

As shown in fig. 3, the operation sequence of the auto-ignition program of the integrated furnace is controlled by the control system according to the parameter change of each detection element, and the execution elements are controlled to operate in sequence as follows:

101, before automatic ignition, judging whether the pressure P1 of a gas main pipe is higher than a safe pressure threshold value, if so, alarming, and if so, opening a hearth pressure pneumatic flap valve PV1 to full open and a combustion air pneumatic regulating valve AV1 to full open;

step 102, judging whether the content A2 of combustible gas in the furnace is lower than the ignition safety content threshold value, if so, opening a nitrogen pneumatic purge valve V6, blowing nitrogen into the furnace, and displacing the gas in the furnace until the gas in the furnace reaches below the safety threshold value;

103, opening 2 pneumatic quick cut-off valves V3 and V4 for the long open fire, and switching on the ignition transformer BE for the long open fire to ignite the long open fire;

104, after detecting that flame of the long open fire exists in the B0, opening 2 main fire nozzle pneumatic quick cut-off valves V1 and V2, setting the opening of a main fire nozzle gas pneumatic regulating valve FV1 at 15-25%,

105, detecting whether main flames exist or not by a main flame nozzle flame detection B1, and setting the opening of a main flame nozzle gas pneumatic regulating valve FV1 to be 75-85% after the main flames are detected; the opening degree of a gas pneumatic regulating valve FV2 of 3 fire distributing nozzles is set to be 15-25%;

106, judging whether the pressure P5 of the tail gas is higher than a safety pressure threshold value, and if so, opening a tail gas pneumatic quick cut-off valve V5;

this concludes the ignition sequence.

As shown in fig. 4, the automatic fire extinguishing control method of the automatic ignition control device is characterized by comprising the following sequential steps:

step 201, closing 2 main fire nozzle pneumatic quick cut-off valves V1 and V2, closing 2 long open fire pneumatic quick cut-off valves V1 and V2, and closing a tail gas pneumatic quick cut-off valve V5;

202, setting the openness of a main burner gas pneumatic regulating valve FV1 to be 0%, and setting the openness of 3 distributor gas pneumatic regulating valves FV2 to be 0%;

step 203, opening a hearth pressure pneumatic flap valve PV1 to full open;

step 204, setting the opening of a combustion air regulating valve AV1 to be 0%;

step 205, judging whether the combustible gas A2 in the furnace reaches below a threshold value;

step 204, if the combustible gas A2 in the furnace is not below the threshold value, opening a nitrogen pneumatic purge valve V6, blowing nitrogen into the furnace, and replacing the gas in the furnace; until the gas in the furnace reaches below a safe threshold;

and step 205, when the combustible gas A2 in the furnace reaches the threshold value or below, ending the fire extinguishing program.

According to the program block diagrams of the figures 3 and 4, an integrated furnace automatic ignition and fire extinguishing control program can be programmed and downloaded into a controller to realize one-key automatic ignition and fire extinguishing through an upper computer HMI.

(8) SIS control loop

Referring to fig. 5, the Safety Instrumented System (SIS) parking logic includes the following steps:

301, when gas pressure P1, P2 and P3 are low and 3 is selected to 2, or main flame detection B1 is used for fire extinguishing or an emergency furnace shutdown button is pressed down, the solenoid valves of the pneumatic quick cut-off valves V1 and V2 lose power to cut off gas of a main burner, and the solenoid valves of the pneumatic quick cut-off valves V3 and V4 lose power to cut off gas of long-time open fire;

302, cutting off the tail gas when the electromagnetic valve V5 of the pneumatic quick cut-off valve is powered off;

and step 303, turning on the solenoid valve of the pneumatic valve V6 to purge nitrogen when the solenoid valve is electrified, and delaying the fixed purging time to lose power.

In step 301, the alarm low limit of the main gas pressure (main flame and long open fire) and the tail gas pressure is 20kPa, and the alarm low limit of the stop is 15 kPa.

In order to normally ignite the main burner and maintain the instrument without executing SIS, a bypass soft button is arranged in the logic interlock, after emergency stop, when the parameter of the SIS instrument is recovered to the normal state of production, a gas cut-off valve and a tail gas cut-off valve are automatically opened by false triggering, and the ignition can be started only by pressing the interlock reset soft button (secondary confirmation is needed).

When the auto-ignition (auto-ignition flag PID _ HAND ═ 1 in fig. 3) and the fire-extinguishing procedure (auto-fire flag PID _ HAND ═ -1 in fig. 4) are performed, the SIS logic needs to be masked and the TC1, TC2, PC, AC control loops are not performed.

The detection input parameters related to the control of the automatic control system of the light-heavy phase oil heating and tail gas burning integrated furnace for producing the needle coke are as follows:

(1) 3 signals (analog quantity) of main gas pressure (P1, P2 and P3);

(2) 1 signal (analog quantity) of main burner gas flow (F1);

(3) 1 signal (analog quantity) of gas flow (F2) of a fire distribution nozzle;

(4) 1 (analog) signal of exhaust pressure (P5);

(5) stack outlet front pressure (P4) signal 1 (analog);

(6) 1 signal (analog) for light phase oil outlet temperature (T5);

(7) heavy phase oil outlet temperature (T3) signal 1 (analog);

(8) 1 signal (analog quantity) of the oxygen content (A1) of the smoke;

(9) 1 (analog quantity) signal of outlet flow (F4) of heavy phase oil frequency conversion pump;

(10) 1 signal (analog quantity) of the outlet flow (F3) of the light phase oil frequency conversion pump;

(11) the main burner flame spectrum detection (B1) signals 1 (switching value).

The automatic control system of the light-heavy phase oil heating and tail gas burning integrated furnace for producing the needle coke controls the output parameters to have the following steps:

(1) 1 signal (analog quantity) of main burner gas flow regulation (FV 1);

(2) 1 signal (analog quantity) of gas flow regulation (FV2) of the fire nozzle;

(3) 1 signal (analog quantity) of pressure regulation (PV1) before the outlet of the flue (furnace);

(4) 1 signal (analog quantity) of combustion air regulation (AV1) of a main burner;

(5) 1 signal (analog quantity) of a heavy phase oil variable frequency pump frequency regulation (FP 1);

(6) 1 signal (analog quantity) of frequency regulation (FP2) of the light-phase oil variable-frequency pump;

(7) the main flame is cut off rapidly (V1, V2) 2 signals (switching value);

(8) 2 signals (switching value) of Changming flame fast cut-off (V3, V4);

(9) tail gas fast cut-off (V5) signals 1 (switching value);

(10) nitrogen purge control (V6) signal 1 (on/off).

The above embodiments are implemented on the premise of the technical solution of the present invention, and detailed embodiments and specific operation procedures are given, but the scope of the present invention is not limited to the above embodiments. The methods used in the above examples are conventional methods unless otherwise specified.