KR101179679B1 - Control device of inlet air flow rate for coke oven and control method thereof - Google Patents

Abstract

The present invention relates to an apparatus for controlling the inflow air flow rate of a coke oven and a control method thereof, comprising: a plurality of combustion chambers having an air inlet box and a gas inlet box, and a coal briquette for carbonizing coke with heat burned in the combustion chambers; An air inlet box including a carbonization chamber, waste streams from which exhaust gas combusted from each combustion chamber is discharged, small flues from which each waste barb is joined, and large flues from which small flues are joined via a chimney valve, A flow rate detection sensor and an inlet temperature detection sensor provided at the inlet air to detect the flow rate and temperature of the inlet air, an oxygen sensor and an outlet temperature detection sensor at the waste valve to detect the oxygen concentration and temperature of the exhaust gas, and a flow rate detection sensor Is electrically connected in communication with the inlet temperature detection sensor, the oxygen concentration sensor, and the outlet temperature detection sensor, and collected from the sensors. And a controller for calculating the detection information to control the air flap of the air inlet box and to adjust the inflow air flow rate.

Coke oven, combustion chamber, air flap, chimney valve

Description

CONTROL DEVICE OF INLET AIR FLOW RATE FOR COKE OVEN AND CONTROL METHOD THEREOF}

1 is a view schematically showing a coke oven according to an embodiment of the present invention.

FIG. 2 is a view schematically showing an air inlet box of the combustion chamber of FIG. 1. .

3 is a view schematically showing a waste side of the combustion chamber of FIG.

4 is a diagram illustrating a process of controlling the air flow rate of the coke oven according to an embodiment of the present invention.

FIG. 5 is a graph showing the flow rate of the inlet air measured in the air inlet box of FIG. 1.

FIG. 6 is a graph illustrating a relationship between an exhaust gas temperature and an oxygen concentration measured at the waste valve of FIG. 1.

FIG. 7 is a graph showing the inlet air flow rate measured in the air inlet box under the operating conditions of 100% of the opening degree of the chimney valve during the reversing period.

FIG. 8 is a graph showing the inflow air flow rate measured in the air inlet box under the operating condition of the opening degree of 0% of the chimney valve during the reversing period.

9 is a graph showing the flow rate of the exhaust gas measured under the operating conditions of 100% of the opening degree of the chimney valve during the reversing period.

10 is a graph showing the flow rate of the exhaust gas measured under the operating conditions of the opening degree of 0% of the chimney valve during the reversing period.

The present invention relates to an air flow rate control apparatus for a coke oven and a control method thereof, and more particularly, to control an optimum air flow rate required for combustion according to different combustion characteristics of an individual combustion chamber to improve combustion efficiency of the combustion chamber. An apparatus for controlling air flow of a coke oven and a control method thereof.

In general, a coke manufacturing process in a steel mill charges coal mixture into a carbonization chamber of a coke oven, and heat generated by the mixing gas and combustion air is transferred to the carbonization chamber to dry the coke. One of the steelmaking processes.

The coke oven is composed of a plurality of carbonization chambers into which the coal mixture is charged, and individual combustion chambers separated from the carbonization chambers and the refractory bricks and burning inside the coke oven. These individual combustion chambers consist of approximately 37 (or 36) locations in a coke oven with each individual carbonization chamber in between.

Therefore, as the quality of the coke and the operation rate of the coke oven are determined according to the temperature of the combustion chamber, the combustion management to determine the low temperature of the combustion chamber is very important in the operation of the coke oven.

The required total fuel gas flow rate is calculated according to the operating rate of the coke oven, and the required amount of fuel gas is supplied to each combustion chamber. The outside air combusting the fuel gas is introduced through the air inlet box and the inflow is controlled by adjusting the cross-sectional area of the air flap. At this time, the excessive air ratio of the exhaust gas is maintained at about 1.2 to 1.3 so as to increase the combustion efficiency and prevent incomplete combustion.

However, since the excess air ratio of the exhaust gas is the oxygen concentration measured by collecting the exhaust gas discharged from 37 individual combustion chambers, it is difficult to maintain the constant combustion characteristics of each individual combustion chamber having a variation in combustion characteristics.

The air flow into each combustion chamber through each air inlet box varies, unlike fuel gas, depending on the chimney's draft capacity. Therefore, the flow rate of air flowing into the individual combustion chamber is introduced regardless of the amount of fuel flowing into the individual combustion chamber, so that each individual combustion chamber is operated in the state of excess or insufficient air ratio.

Thus, there is a problem in that it is not possible to calculate the optimum required air flow rate for each individual combustion chamber having different combustion characteristics. In addition, according to the opening rate of the chimney valve (chimney valve) disposed between the small flue and large flue, there is a problem that can not be reflected in the prediction or operation control of the air flow.

And, in order to uniformly manage the low temperature of the coke oven, it has a reversing time for changing the air and fuel gas injection directions every 20 minutes. At this reversal, fuel gas injection stops and only the air flowing through the air inlet box flows into the heat storage chamber and the combustion chamber.

Therefore, when the combustion is stopped under constant ventilation conditions, the air flow rate is increased by 1.5 times compared to the air flow rate when the combustion occurs. In this process, heat loss inside the combustion chamber of the coke oven is caused by inflow air, and there is a problem of waste of fuel required to raise the low temperature of the coke oven and lowering the operation rate of the coke oven.

The present invention is to solve the above problems, an object of the present invention is to derive the optimum combustion conditions for the individual combustion chambers of the coke oven to control the operation of the air flow flowing into the combustion chamber, the air during the reversing period It is to provide an air flow rate control device of the coke oven and a control method thereof that can minimize the loss of heat to minimize heat loss.

In order to achieve the above object, the inlet air flow rate control apparatus of the coke oven of the present invention includes a plurality of combustion chambers having an air inlet box and a gas inlet box, and charging coal coal to carbonize coke with the heat burned in the combustion chambers. An air inlet box including a carbonization chamber, waste streams from which exhaust gas combusted from each combustion chamber is discharged, small flues from which each waste barb is joined, and large flues from which small flues are joined via a chimney valve, A flow rate detection sensor and an inlet temperature detection sensor provided at the inlet air to detect the flow rate and temperature of the inlet air, an oxygen sensor and an outlet temperature detection sensor at the waste valve to detect the oxygen concentration and temperature of the exhaust gas, and a flow rate detection sensor Electrically connected in communication with the inlet temperature detection sensor, the oxygen concentration sensor, and the outlet temperature detection sensor and collected from the sensors. And a controller for calculating the detection information to control the air flap of the air inlet box and to adjust the inflow air flow rate.

The flow rate detection sensor includes a pitot tube, and the end portion of the pitot tube is preferably arranged to coincide with the cross section of the air flap of the air inlet box.

The controller can further control the amount of opening of the chimney valve.

In addition, the method for controlling the inflow air flow rate of the coke oven of the present invention includes detecting combustion conditions for a plurality of individual combustion chambers, collecting and calculating respective detection information, and based on the collected and calculated information. Diagnosing respective combustion characteristics for the individual combustion chambers, calculating respective inlet air flow rates corresponding to the individual combustion chambers, and the air in the air inlet box such that the calculated required inlet air flow rate is introduced into each individual combustion chamber. Driving control of the flap.

In the operation control step, it is possible to control the opening amount of the chimney valve during the reversing period, in which case, it is preferable to control the opening amount of the chimney valve to 0%.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

1 is a view schematically illustrating a coke oven according to an embodiment of the present invention, FIG. 2 is a view schematically showing an air inlet box of the combustion chamber of FIG. 1, and FIG. 3 is a disposal of the combustion chamber of FIG. 1. It is a figure which shows a side schematically.

Referring to these drawings, the coke oven according to the present embodiment is composed of carbonization chambers 20 for charging coal mixture and combustion chambers 10 for providing heat to the carbonization chambers 20. . The carbonization chamber 20 and the combustion chamber 10 are paired with each other to form a unit wall 15. In the coke oven approximately 37 (or 36) months 15 are constructed, in which the individual carbonization chambers 20 and the individual combustion chambers 10 are separated by refractory bricks.

Each combustion chamber 10 is provided with a gas inlet box 12 for supplying fuel gas and an air inlet box 11 for supplying oxygen for combustion of the fuel gas. Then, a waste valve 13 for discharging the exhaust gas combusted in the individual combustion chamber 10 is provided.

The plurality of waste valves 13 are connected to the small flues 30, and the small flues 30 are connected to the large flue 40 with each chimney valve 35 interposed therebetween. 40 is connected to the chimney 50.

 Therefore, the heat generated as the air and fuel gas introduced into the combustion chamber through the air inlet box 11 and the gas inlet box 12 are burned to produce coke by carbonizing the coal mixture charged in the carbonization chamber 20. And, the combustion and the generated exhaust gas is discharged to the chimney 50 through the small flue 30 and the large flue 40 through the waste side (13).

 At this time, the excess air ratio of the exhaust gas discharged to the waste side 13 of each individual combustion chamber 10 should be maintained at about 1.2-1.3 to prevent incomplete combustion of the fuel gas.

As such, in order for each individual combustion chamber 10 to have a combustion condition close to complete combustion, each combustion chamber 10 is diagnosed with different combustion characteristics and operated to provide an optimum air flow rate corresponding to the combustion characteristics. It is necessary to control.

 Therefore, the air inlet box 11 includes a flow rate detection sensor 61 for detecting the inflow air flow rate and a first temperature sensor for detecting the temperature of the intake air to diagnose operating characteristics of each individual combustion chamber 10. 62 is provided. (See Fig. 2)

The coke oven has a reversing time that changes the direction of injection of inlet air and fuel gas every 20 minutes to uniformly manage the furnace. Therefore, since the air flap 14 of the air inlet box 11 is opened and closed every 20 minutes, the flow rate detection sensor 61 is preferably installed so as not to interfere with the opening and closing operation of the air flap 14.

In the present embodiment, the use of the pitot tube 61a as the flow rate detection sensor 61 for detecting the air flow rate flowing into the air inlet box 11.

This pitot tube 61a forms a hole in the lower part of the air inlet box 11, and it connects through the hole, and installs it so that it may not interfere with the operation control of a coke oven. At this time, the end of the pitot pipe 61a is preferably installed to match the cross section of the air flap 14 to reduce the measurement error.

The pitot tube 61a can detect the dynamic pressure and static pressure of the inlet air, and the pitot tube 61a is connected to the signal converter 65 to convert the detected information into a battery signal.

The first temperature detection sensor 62 is attached to one side of the pitot tube 61a so as to be positioned at a predetermined height, preferably at the center of the vertical cross-sectional area, from the lower portion of the air inlet box 11. The first temperature sensor 62 uses a thermocouple thermometer to generate detection information on the temperature of the incoming air as an electrical signal.

In addition, an oxygen concentration detection sensor 63 for detecting the oxygen concentration of the exhaust gas and a second temperature detection sensor 64 for detecting the temperature of the exhaust gas are disposed in the waste sides 13 of the individual combustion chambers 10. It is provided. (See Figure 3)

The signal converter 65, the first temperature detection sensor 62, the oxygen concentration detection sensor 63, and the second temperature detection sensor 64 connected to the pitot pipe 61a which is the flow rate detection sensor 61 are each a controller 60. Are electrically connected to each other.

This controller 60 is electrically connected to automatically control the opening degree of the air flap 14 of the air inlet box 11. Therefore, by collecting and calculating the information detected from the respective sensors to diagnose the combustion characteristics for the individual combustion chambers 10, calculate and supply the required air flow rate required for each combustion chamber calculated according to the combustion characteristics Driving control. .

In addition, the controller 60 is electrically connected to automatically control the opening degree of the chimney valve 35 disposed between the small flue 30 and the large flue 40. Therefore, the controller 60 may control the inflow air flow rate introduced into the individual combustion chamber 10 by the natural ventilation force of the chimney by controlling the opening rate of the chimney valve 35.

4 is a diagram illustrating a process of controlling the air flow rate of the coke oven according to an embodiment of the present invention.

Referring to FIG. 4, the process of controlling the inflow air flow rate of the coke oven includes a combustion condition detection step S1 for individual combustion chambers, a collection and calculation step S2 of detection information, and combustion characteristics for individual combustion chambers. A diagnosis step S3, an optimum air flow rate calculation step S4 for the respective combustion chambers, and an operation control step S5 are included.

First, in the combustion condition detection step S1 for the individual combustion chambers 10, the pitot tube 61a provided in each air inlet box 11 and the first temperature detection sensor 62 are connected to the individual combustion chambers. The air flow rate for calculating the flow rate of the incoming air and the information on the temperature of the incoming air are detected in real time.

In addition, oxygen of the exhaust gas discharged from the respective combustion chambers 10 through the oxygen concentration detection sensor 63 and the second temperature detection sensor 64 installed in the waste valves 13 of the respective combustion chambers 10. Detects information about concentration and temperature in real time.

In the detection information collecting and calculating step S2, the controller detects the information detected in real time through the pitot tube 61a, the first temperature detection sensor 62, the oxygen concentration detection sensor 63, and the second temperature detection sensor 64. Collected and stored in 60, the stored information is calculated by the controller 60 as information for diagnosing combustion characteristics for the individual combustion chambers 10.

For example, the process of calculating the inflow air flow rate from the pressure detection information on the inflow air of the air inlet box 11 detected from the pitot tube 61a through the signal converter in the controller 60 will be described below.

The air flow rate Q flowing through the air inlet box 11 is calculated as the product of the cross-sectional area S and the flow rate v of the air inlet box 11. According to the shape of the air inlet box shown in FIG. 2, the cross-sectional area S through which air flows can be obtained as shown in Equation 1 below. At this time, the cross section of the air inlet box 11 can be adjusted using the air flap 14.

Here, S is a cross section, a is the upper side length of an open surface, b is the lower side length of an open surface, and c is high.

The dynamic pressure ΔP obtained using the pitot tube 61a has a flow rate v and a relational expression as shown in Equation 2 below.

Where v is the flow rate, ΔP is the dynamic pressure, ρ is the air density, and c is the pitot tube coefficient. As described above, the air flow rate Q can be obtained by multiplying the cross-sectional area S of the air inlet box 11 by the flow rate v.

And, it can be obtained through the following equation (3) after the standard flow rate (Qs) corrected temperature.

Here, T is the temperature of the inlet air detected through the first temperature detection sensor 62.

In addition, it is a matter of course that the calorific value for the respective combustion chambers 10 can be calculated based on the calculated inflow air flow rate, inlet air temperature, exhaust gas oxygen concentration, and exhaust gas temperature. At this time, the flow rate of the fuel gas flowing into each individual combustion chamber 10 has the same condition.

In the combustion characteristic diagnosis step S3 for the individual combustion chambers, the respective combustion characteristics for the individual combustion chambers 10 are diagnosed using the detection information collected and calculated by the controller.

As an example, the air flow rate flowing through the A inlet box 11 for each of the individual combustion chambers 10 measured in # 59 to # 62 months 15, and the oxygen concentration and temperature characteristics of the waste gas from the waste stream. Explain.

FIG. 5 is a graph illustrating a flow rate of air measured in the air inlet box of FIG. 1, and FIG. 6 is a graph illustrating a relationship between the temperature of the exhaust gas and the oxygen concentration measured in the waste valve of FIG. 1.

These figures show that the air flow rates introduced into the individual combustion chambers 10 through the air inlet box 11 are different from each other combustion chamber 10. In addition, it can be seen that the inlet air flow rate during the reversing period increases about 1.5 times or more compared to the inlet air flow rate during the normal operation period. In addition, it can be seen that the oxygen concentration and temperature of the exhaust gases discharged to the waste stools 13 of the respective combustion chambers 10 are also different.

Based on the detection information, combustion characteristics such as fuel gas flow rate and combustion state of each individual combustion chamber 10 may be diagnosed.

In step S4 of calculating the optimum air flow rates for the individual combustion chambers, the respective optimum air flow rates required for the individual combustion chambers 10 are calculated according to the combustion characteristics of the individual combustion chambers 10.

At this time, the calculated optimum air flow rate maintains the excess air ratio 1.2-1.5 of the exhaust gas so that the combustion gas flowing into the respective combustion chamber 10 burns close to complete combustion. Accordingly, the combustion efficiency for the individual combustion chambers 10 may be improved, and the amount of exhaust gas may be reduced to reduce heat loss due to the exhaust gas.

And, in the operation control step (S5), the controller 60, during the normal operation period of the individual combustion chambers 10, the air flap of each air inlet box so that the calculated optimum air flow rate flows into the individual combustion chambers. To control the amount of opening.

The controller 60 also controls the amount of opening of the chimney valve 35 during the reversing period of the individual combustion chambers 10. In particular, the opening degree of the chimney valve 35 is controlled to 0% to minimize the flow rate of the inlet air during the reversing period in which the air flow rate into the individual combustion chambers 10 is determined by the natural ventilation force of the chimney 60.

7 is a graph showing the inlet air flow rate measured in the air inlet box under the operating condition of 100% opening degree of chimney valve during reversing period, and FIG. 8 is 0% opening degree of chimney valve during reversing period. This is a graph showing the incoming air flow velocity measured in the air inlet box under the operating conditions of.

Through these figures, the flow rate of air flowing into the individual combustion chamber under the operating condition of the opening degree of 0% of the chimney valve 35 during the reversing period is the air flow rate flowing under the operating condition of the opening rate of 100% of the chimney valve 35. It can be seen that about 2-3 m / s is reduced compared to.

9 is a graph showing the flow rate of the exhaust gas measured under the operating conditions of 100% opening degree of chimney valve during reversing period, and FIG. 10 is the operating condition of 0% opening degree of chimney valve during reversing period. It is a graph showing the flow rate of the measured exhaust gas.

Through these figures, the flow rate of the exhaust gas measured under the operating condition of the opening rate of 100% of the chimney valve 35 during the reversing period is measured by the exhaust gas measured under the operating condition of the opening rate of 50% of the chimney valve 35. It can be seen that the reduction of about 90 Nm ³ / min compared to the flow rate of.

Therefore, when the chimney valve 35 between the small flue 30 and the large flue 40 is closed to maintain an operating state of 100% opening degree, the flow rate of the exhaust gas is about 180 Nm ³ / min (10,800 Nm ³ / hr It can be seen that the degree is reduced. As a result, by adjusting the opening degree of the chimney valve 35 during the reversing period, it is possible to prevent heat loss of about 10,800 Nm 3 / hr due to the exhaust gas.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, the apparatus for controlling the inflow air flow rate of the coke oven and the control method thereof according to the present invention measure the air flow rate and the temperature flowing into the air inlet box, and the exhaust gas oxygen concentration and the temperature discharged from the waste stool. Diagnose the combustion characteristics of the individual combustion chambers with the engine and improve the overall operating capacity by controlling the air flap of the air inlet box to provide the optimum air flow rate for the individual combustion chambers according to the combustion characteristics, and during the reversing period By controlling the opening rate of the valve to 0%, it has an effect of minimizing heat loss caused by excessively flowing air flow rate.

Claims (7)

A plurality of combustion chambers having an air inlet box and a gas inlet box; A carbonization chamber for charging the coal briquettes so as to carbonize the coke with the heat burned in the combustion chambers; Waste toilets through which exhaust gas combusted from each combustion chamber is discharged; Small flues in which each waste stool is joined; The small flues include a large flue that is joined with a chimney valve in between, A flow rate detection sensor and an inlet temperature detection sensor provided in the air inlet box and detecting a flow rate and a temperature of the inlet air; An oxygen sensor and an outlet temperature detection sensor provided at the waste valve to detect an oxygen concentration and a temperature of exhaust gas; And And electrically connected with the flow rate detection sensor, the inlet temperature detection sensor, the oxygen concentration sensor, and the outlet temperature detection sensor, and calculate the detection information collected from the sensors to control the air flap of the air inlet box. A controller for adjusting the incoming air flow rate; Including, The flow rate detection sensor is inlet air flow rate control apparatus of the coke oven comprising a pitot tube. delete The method of claim 1, Inlet air flow rate control apparatus of the coke oven is arranged so that the end of the pitot tube coincides with the cross section of the air flap of the air inlet box. The method of claim 1, And the controller further controls the amount of opening of the chimney valve. Detecting combustion conditions for a plurality of individual combustion chambers, respectively; Collecting and calculating the respective detection informations; Diagnosing respective combustion characteristics for the individual combustion chambers based on the collected and calculated information; Calculating respective inflow air flow rates corresponding to the individual combustion chambers; And Operating control of the air flap of the air inlet box such that the calculated required inlet air flow rate flows into each individual combustion chamber; Inlet air flow rate control method of the coke oven comprising a. The method of claim 5, In the operation control step, the inflow air flow rate control method of the coke oven for controlling the opening amount of the chimney valve during the reversing period. The method of claim 6, A method of controlling the inflow air flow of a coke oven which controls the opening amount of the chimney valve to 0% during the reversing period.

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