JP2013221129A - Method for controlling introduction of combustion air in coke dry quenching facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling introduction of combustion air in a coke dry quenching facility, whereby the amount of air required for combustion of combustion gas in circulating gas can be supplied, even when the amount of red-hot coke changes.SOLUTION: A method for controlling introduction of combustion air, wherein air for burning combustion gas is introduced into circulating gas in a coke dry quenching facility 10, comprises: installing an air introducing means 25 into a cooling chamber 11 for cooling red-hot coke, wherein the air introducing means 25 is equipped with an intake port that spontaneously sucks air by utilizing pressure difference between the circulating gas and the atmosphere, an air fan for forced introduction of air, and a flow control valve for controlling the amount of air introduced via the intake port or the air fan depending on the concentration of the combustion gas; spontaneously sucking air by stopping the air fan and opening the inlet port in a process wherein the concentration of the combustion gas decreases from the concentration at steady-load operation; and forcibly introducing air by shutting the inlet port and operating the air fan in a process wherein the concentration of the combustion gas increases toward the concentration at steady-load operation.

Description

The present invention relates to a waste heat recovery boiler from a cooling chamber that cools red coke in order to burn the combustion gas contained in the cooling circulation gas flowing in the coke dry fire extinguishing equipment (hereinafter sometimes referred to as CDQ). TECHNICAL FIELD The present invention relates to a combustion air introduction control method for introducing air into a circulating gas directed toward the vehicle.

The main component of the circulating gas flowing in the CDQ is nitrogen gas. However, if the red hot coke is continuously charged into the cooling chamber (also referred to as the CDQ chamber), the red hot coke and the combustion gas (the coke not discharged) The combustible gas such as CO, H ₂ or the like which is the fuel) is brought in, so the concentration of the combustion gas in the circulating gas gradually increases. For this reason, for example, as described in Patent Document 1, the air sucked by the air blowing blower is mixed into the circulating gas flowing out from the CDQ chamber, and the circulating gas is introduced before the circulating gas flows into the waste heat recovery boiler. By burning a part of the combustion gas therein, the concentration of the combustion gas in the circulating gas is adjusted to a certain range (for example, the CO concentration is about 10% and the H ₂ concentration is about 3%).

JP-A-9-59644

In general, the amount of red hot coke charged into the CDQ varies depending on the operating conditions of the coke oven, so the amount of heat in the circulating gas flowing into the waste heat recovery boiler also varies, and the amount of steam generated in the waste heat recovery boiler There is a problem that fluctuates. For this reason, in the air blowing method in the coke dry fire extinguishing equipment of Patent Document 1, the air is blown along the flow direction of the circulating gas into the downstream chamber of the slow dust plate provided in the duct that sends the circulating gas from the CDQ chamber to the waste heat recovery boiler. Provide multiple inlets, select one of the multiple inlets according to the amount of combustion gas (combustible component) in the circulating gas or the amount of heat input from red hot coke, and select the selected outlet. Air is blown from the entrance. However, there arises a problem that the air blowing path becomes complicated and the control of air blowing becomes complicated. Furthermore, since the air blowing blower is always operated in order to take in air, there is a problem that the operating cost of the equipment becomes high.

The present invention has been made in view of such circumstances, and even if the amount of red hot coke charged in the CDQ fluctuates, it is possible to supply the amount of air necessary for combustion of the combustion gas in the circulating gas with a simple configuration. An object of the present invention is to provide a method for controlling the introduction of combustion air in a coke dry fire extinguishing facility that is capable of stable CDQ operation.

The method for controlling the introduction of combustion air in the coke dry fire extinguishing equipment according to the present invention, which meets the above-mentioned object, is to burn the combustion gas contained in the circulating gas into the circulating gas flowing into the waste heat recovery boiler of the coke dry fire extinguishing equipment. In the method for controlling the introduction of combustion air in a coke dry fire extinguishing system that introduces air,
A cooling chamber that receives and cools reddish coke charged in the coke dry fire extinguishing equipment, naturally sucks air using a pressure difference between the circulating gas and the atmosphere, and an air fan that forcibly introduces air And an air introduction means comprising a flow rate adjusting valve for adjusting the amount of air introduced through the intake port or the air fan according to the concentration of the combustion gas in the circulating gas,
In the process in which the concentration of the combustion gas is lower than the concentration at the time of steady load operation, the air fan of the air introduction means is stopped and the intake port is opened to naturally suck air, and the concentration of the combustion gas is the steady load. In the process of increasing toward the concentration at the time of operation, the air inlet of the air introducing means is closed and the air fan is operated to forcibly introduce air.

In the method for controlling the introduction of combustion air in the coke dry fire extinguishing equipment according to the present invention, when switching from the forced introduction to the natural suction or from the natural suction to the forced introduction, the valve opening degree of the flow control valve is It is preferable to set based on the capacity coefficient of the flow rate control valve calculated using the amount of air necessary for combustion of the combustion gas and the inlet side pressure and the outlet side pressure of the flow rate control valve.

In the method for controlling the introduction of combustion air in the coke dry fire extinguishing facility according to the present invention, the concentration of the combustion gas increases during the natural suction of air, and the amount of air necessary for combustion of the combustion gas is determined from the pressure difference. When the amount of natural suction air that is determined is exceeded, the natural suction is stopped and the forced introduction is started, and at the time of forced introduction of air, the concentration of the combustion gas decreases, and the amount of air necessary for combustion of the combustion gas is reduced. It is preferable to stop the forced introduction and start the natural suction when the amount of natural suction air determined by the pressure difference is less than or equal.

In the method for controlling the introduction of combustion air in the coke dry fire extinguishing equipment according to the present invention, the air inlet that naturally sucks air into the cooling chamber of the coke dry fire extinguishing equipment using the pressure difference between the circulating gas in the cooling chamber and the atmosphere And an air fan that forcibly introduces air and a flow rate adjusting valve that adjusts the amount of air introduced through the intake port or the air fan according to the concentration of the combustion gas. Air required for combustion is introduced by natural suction when the concentration of combustion gas decreases from the concentration during steady load operation and by forced introduction when the concentration of combustion gas increases toward the concentration during steady load operation Therefore, a plurality of inlets are provided along the flow direction of the conventional circulating gas, and a plurality of inlets are provided depending on the amount of combustion gas in the circulating gas or the amount of heat input brought into the red hot coke. From selecting one blowing port, as compared to blown method air from blowing port selected, it is possible to simplify the device configuration, it is possible to reduce the equipment cost.
And during low-load operation of the coke dry fire extinguishing equipment, where the concentration of combustion gas decreases, the operation of the air fan can be stopped, reducing the energy consumption of the air fan compared to the conventional coke dry fire extinguishing equipment (For example, about 25% reduction), and the running cost of the equipment can be reduced.

In the method for controlling the introduction of combustion air in the coke dry fire extinguishing equipment according to the present invention, when switching from forced introduction to natural suction or from natural suction to forced introduction, the valve opening of the flow control valve is necessary for combustion of combustion gas. Set based on the capacity coefficient of the flow control valve calculated using the correct air amount and the inlet side pressure and the outlet side pressure of the flow control valve. Since the valve opening is set in advance, the required air volume is reliably introduced by minimizing the response delay of the flow control valve due to sudden pressure fluctuations in the air introduction means that occur when switching the air introduction method. be able to. As a result, the concentration of the combustion gas in the circulating gas can be more accurately controlled, which can contribute to the safe and stable operation of the coke dry fire extinguishing equipment.
Furthermore, by accurately controlling the concentration of the combustion gas in the circulating gas, it is possible to prevent an increase in the oxygen concentration in the circulating gas, and high-temperature oxidation of metal members exposed to the circulating gas in the coke dry fire extinguishing equipment. Corrosion can be prevented and stable operation of the coke dry fire extinguishing equipment can be further promoted.

In the method for controlling the introduction of combustion air in the coke dry fire extinguishing equipment according to the present invention, the natural suction air in which the concentration of the combustion gas increases during the natural suction of the air and the amount of air necessary for the combustion of the combustion gas is determined from the pressure difference If the amount exceeds, the natural suction is stopped and forced introduction is started.When forced air is introduced, the concentration of the combustion gas decreases, and the amount of air required for combustion gas combustion is less than the amount of natural suction air determined from the pressure difference. Then, when the forced introduction is stopped and the natural suction is started, the operator of the coke dry fire extinguishing equipment, for example, according to the change in the amount of red hot coke charged or according to the change in the concentration of the combustion gas in the circulating gas Thus, compared with the case where the air introduction method is changed, the determination of switching the air introduction method is made uniformly, and the operation of the coke dry fire extinguishing equipment can be stabilized.

It is explanatory drawing of the coke dry fire extinguishing equipment to which the introduction control method of the combustion air in the coke dry fire extinguishing equipment concerning one embodiment of the present invention is applied. It is explanatory drawing of the air introduction means of the coke dry fire extinguishing equipment to which the introduction control method of the combustion air in the coke dry fire extinguishing equipment is applied. It is a graph which shows the relationship between Cv value and valve opening degree of the flow control valve of an air introduction means. It is a graph which shows the relationship between the pressure in a ring duct, and the amount of required air introduce | transduced via the inlet port of an air introduction means. (A) to (D) are the time variation pattern of the input coke amount and the concentration of the combustion gas, the time variation pattern of the required air amount, the time variation pattern of the operating state of the air fan, and the valve opening time of the flow control valve, respectively. It is explanatory drawing of a fluctuation pattern. In the case of switching the introduction of air from natural suction to forced introduction, (A) shows the relationship between the responsiveness of the valve opening when the valve opening of the flow control valve is preset based on the Cv value and the time variation of the air amount. (B) is explanatory drawing which shows the relationship between the responsiveness of a valve opening degree, and the time change of an air quantity at the time of setting the valve opening degree of a flow control valve based on required air quantity.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
First, the coke dry fire extinguishing equipment (CDQ) 10 to which the combustion air introduction control method in the coke dry fire extinguishing equipment according to one embodiment of the present invention is applied will be described.
As shown in FIG. 1, the coke dry fire extinguishing equipment 10 receives a red hot coke discharged from a coke oven (not shown) from the upper part and moves it downward while circulating gas (main component is nitrogen gas) blown into the lower part. A cooling chamber (chamber) 11 for cooling, one side connected to the cooling chamber 11, a primary duct 12 for exchanging heat with reddish coke in the cooling chamber 11 and taking out the circulating gas that has become high temperature, and a primary duct The waste heat recovery boiler 13 is connected to the other side of the heat exchanger 12 and exchanges heat with the hot circulating gas flowing in via the primary duct 12 to generate steam, and is discharged from the waste heat recovery boiler 13. And a secondary duct 14 for returning the circulating gas whose temperature has decreased to the lower part of the cooling chamber 11.

Reference numeral 15 is a charging device provided at the upper part of the cooling chamber 11 for charging red hot coke into the cooling chamber 11, reference numeral 16 is a primary dust catcher provided in the primary duct 12, reference numeral 17 is 1 This is a dust discharge device for taking out the dust captured by the next dust catcher 16. Reference numerals 18 and 19 are secondary dust catchers and gas circulation fans provided in the secondary duct 14, respectively. Reference numeral 20 is a water supply preheater that further reduces the temperature of the circulation gas by exchanging heat between the circulation gas and water. Reference numeral 21 denotes a coke discharging device that takes out the cooled coke from the lower portion of the cooling chamber 11.

The cooling chamber 11 is provided on the upper side of the cooling chamber 11 and is provided on the lower side of the cooling chamber 11 in communication with the prechamber 22 in which the stored red hot coke is temporarily stored, and the lower portion of the prechamber 22. A cooling chamber 23 that cools the coke with the circulating gas that is blown in, and a ring duct 24 that communicates with the cooling chamber 23 and is provided outside the upper portion of the cooling chamber 23 and to which one side of the primary duct 12 is connected. . Due to such a configuration, combustion gas composed of combustible gas such as CO, H _2, etc., which is unburned coke, is mixed in the circulating gas due to contact between red hot coke and the circulating gas. As a result, the circulating gas flowing into the primary duct 12 via the ring duct 24 contains combustion gas.
When the circulating gas in the ring duct 24 is exhausted by the gas circulation fan 19 provided in the secondary duct 14 via the primary duct 12 and the waste heat recovery boiler 13, it is blown into the lower part of the cooling chamber 23. Since the circulating gas passes through the coke layer deposited in the cooling chamber 23 and flows into the ring duct 24, pressure loss occurs, and the inside of the ring duct 24 can be made lower than atmospheric pressure (negative pressure).

For this reason, by connecting the air introduction means 25 to the ring duct 24 and introducing air into the ring duct 24, a part of the combustion gas in the circulation gas is burned, and the concentration of the combustion gas contained in the circulation gas Are managed within a certain range. As shown in FIG. 2, the air introduction means 25 includes an intake port 27 having an on-off valve 26 that naturally sucks air using a pressure difference between the circulating gas in the ring duct 24 and the atmosphere, and an air An air fan 28 forcibly suctioning (forcibly introducing), a flow rate adjusting valve 29 for adjusting the amount of air introduced through the intake port 27 or the air fan 28 according to the concentration of the combustion gas in the circulating gas, and air It has a flow meter 30 that measures the flow rate and confirms the adjustment result by the flow rate control valve 29, and an air introduction pipe 31 that guides the air that has passed through the flow rate control valve 29 to the ring duct 24.

Here, the air introduction means 25 includes a combustion gas concentration meter that measures the concentration of the combustion gas contained in the circulating gas in the ring duct 24, a gas pressure meter that measures the pressure of the circulating gas in the ring duct 24, and a flow meter. 30 has an inflow air pressure gauge and an inflow air thermometer for measuring the pressure and temperature of air introduced through the air inlet 27 or the air fan 28, respectively.

In addition, the air introduction means 25 is (1) the coke oven is in a steady load operation state, a certain amount of red hot coke is charged into the CDQ 10, and the concentration of the combustion gas in the circulating gas is a constant value (concentration during steady load operation). ) (2) When the coke oven changes to the minimum load operation state, the amount of red hot coke charged into the CDQ10 decreases, and the concentration of the combustion gas in the circulating gas decreases from the concentration during steady load operation (3) When the minimum load operation of the coke oven continues, the amount of red hot coke charged into the CDQ10 is the minimum value, and the concentration of the combustion gas in the circulating gas is a constant value (concentration during low load operation) And (4) measurement of the concentration of combustion gas with a combustion gas densitometer when the coke oven operation rate returns to steady load operation and the concentration of combustion gas increases towards the concentration during steady load operation. From the results, fuel A function for obtaining an air amount necessary for gas combustion (hereinafter simply referred to as a necessary air amount) and a function for outputting a command signal for setting the valve opening degree of the flow control valve 29 so that the obtained necessary air amount can be obtained. It has a provided valve opening setting unit (not shown).

Further, the air introduction means 25 uses an intake port 27 in which the on-off valve 26 in the air introduction means 25 is in an open state by using the pressure difference between the pressure of the circulating gas in the ring duct 24 and the atmospheric pressure. Exceeds the amount of air that can flow into the ring duct 24 (hereinafter referred to as “natural suction air amount”) through the air flow path that includes the flow meter 30, the flow rate adjustment valve 29 with 100% valve opening, and the air introduction pipe 31. A) When the required air amount exceeds the natural suction air amount (when the on-off valve 26 is opened and the air fan 28 is stopped) during natural air suction, the on-off valve 26 is closed. The operation of the air fan 28 is started. B) When the required amount of air is less than or equal to the natural suction air amount when the air is forcibly introduced (when the on-off valve 26 is closed and the air fan 28 is operated), the air fan 28 Stop and open the on-off valve 26 Air introduction switching determination unit having a function of outputting a command signal for starting the suction has a (not shown).

Furthermore, when the air introduction means 25 switches the intake of the required air into the ring duct 24 from forced introduction to natural suction or from natural suction to forced introduction, the air flow control means 29 sets the valve opening degree of the flow control valve 29 to the necessary air. 3 and a function for calculating a capacity coefficient (hereinafter referred to as Cv value) of the flow rate control valve 29 that is calculated using the amount and the inlet side pressure and the outlet side pressure of the flow rate control valve 29. Based on the relationship between the indicated Cv value and the valve opening degree (degree) of the flow control valve 29 (obtained in advance for each flow control valve 29 to be used), the valve opening value corresponding to the calculated Cv value is obtained. A switching valve opening setting unit (not shown) having a function to obtain and a function to output a command signal for setting the valve opening of the flow rate adjusting valve 29 to the obtained valve opening value is provided.
The Cv value is calculated based on the required air amount V calculated based on the combustion gas concentration value measured by the combustion gas concentration meter, the inlet side air pressure gauges and the outlet air pressure meters arranged on both sides of the flow rate control valve 29. Entry side pressure P ₁ measured by the side air pressure gauge (fan discharge pressure (unit is absolute pressure) when forced introduction, absolute pressure when natural suction), exit side pressure P ₂ (ring duct 24 The pressure of the circulating gas (in absolute units), the air temperature T measured by the inflow air thermometer, and the air specific gravity G determined from the air temperature T are obtained by the following equation.
Cv = (V / 273) · {GT / (P ₁ −P ₂ ) (P ₁ + P ₂ )} ^1/2

The air introduction means 25 includes a valve opening adjustment of the flow rate adjustment valve 29 based on command signals output from the valve opening setting unit, the air introduction switching determination unit, and the switching valve opening setting unit, respectively. A drive unit (not shown) for opening and closing the on-off valve 26 and turning on and off the air fan 28 is provided. The drive unit is provided with a function of adjusting the valve opening degree of the flow rate control valve 29 so that the required air amount flows into the ring duct 24 based on the measurement value of the flow meter 30.
When the flow rate is measured by the flow meter 30, the pressure and temperature of the natural suction air introduced through the air inlet 27 and the pressure and temperature of the forced air introduced through the air fan 28 are different. For this reason, the flow meter 30 uses a flow meter having a design specification of either one of natural suction air and forced introduction air, and when the flow meter 30 is used under conditions different from the design specification, A correction function for converting the measured value is provided.

In the air introduction switching determination unit, first, a correspondence relationship between the pressure difference between the circulating gas pressure in the ring duct 24 and the atmospheric pressure and the amount of natural suction air is obtained in advance, and this correspondence relationship is determined in the ring duct 24. Information converted into the relationship between the pressure of the circulating gas (hereinafter referred to as ring duct internal pressure) and the amount of natural suction air is input to the calculation unit. An example of the relationship between the ring duct internal pressure and the required air amount is shown in FIG. In the ring duct 24, the natural suction air amount and the necessary air amount are synonymous, and therefore, the vertical axis is shown as the necessary air amount in FIG.

Next, when the required air amount obtained by measuring the concentration of the combustion gas with the combustion gas concentration meter is less than the natural suction air amount determined with respect to the internal pressure of the ring duct measured with the gas pressure meter (present in the shaded area in FIG. 4) In the case of (if), it is determined that the necessary amount of air can be introduced by natural suction of air. On the other hand, when the calculated required air amount exceeds the natural suction air amount corresponding to the measured internal pressure of the ring duct (when it exists outside the shaded area in FIG. 4), the necessary air amount is not introduced due to the natural suction of air. It is judged impossible.

Here, the hatched area (including the curve, the lower area of the curve) in FIG. 4 is that the pressure difference between the ring duct internal pressure and the atmospheric pressure is the intake port 27, flow meter 30, valve Pressure loss in the air flow path composed of the flow rate control valve 29 in the 100% opening state and the air introduction pipe 31 (the sum of the pressure loss ΔPd portion of the air flow path excluding the flow rate control valve 29 and the pressure loss ΔPv portion of the flow rate control valve 29) The range in which air can flow into the ring duct 24 through the air flow path is shown.
For this reason, when determining the correspondence between the pressure difference and the natural suction air amount, the relationship between the natural suction air amount and the pressure loss (the pressure loss ΔPd of the air flow path and the pressure loss ΔPv of the flow rate control valve 29) is determined in advance. A ring duct measured with a gas pressure gauge by obtaining pressure loss ΔPd and pressure loss ΔPv obtained from the relationship between the amount of natural suction air and pressure loss with respect to the required air amount obtained by measuring the concentration of combustion gas with a combustion gas concentration meter. When the internal pressure is greater than or equal to ΔPd + ΔPv, it is determined that the necessary amount of air can be introduced by natural air suction. When the value of ΔPd + ΔPv exceeds the ring duct internal pressure measured with a gas pressure gauge, the necessary air amount is obtained by natural air suction. It is judged that the introduction of is impossible.

If the calculated required air volume is equal to or less than the natural suction air volume corresponding to the measured ring duct internal pressure, it is determined that the required air volume can be introduced by natural air suction. When the command signal for continuing the suction is forcibly introduced, a command signal for stopping the forced introduction of air and starting the natural suction of air is output. On the other hand, if the calculated required air volume exceeds the natural suction air volume corresponding to the measured ring duct internal pressure, it is determined that the required air volume cannot be introduced due to natural air suction. The command signal for stopping the natural suction and starting the forced introduction of air is outputted, and the command signal for continuing the forced introduction of air is outputted at the time of forced introduction of air.

Then, the introduction control method of the combustion air in the coke dry fire extinguishing equipment which concerns on one embodiment of this invention is demonstrated.
The method for controlling the introduction of combustion air in the coke dry fire extinguishing equipment according to the present embodiment combusts the combustion gas contained in the circulating gas into the circulating gas flowing into the waste heat recovery boiler 13 of the coke dry fire extinguishing equipment (CDQ) 10. The air is introduced into the ring duct 24 of the cooling chamber 11 that receives and cools the red hot coke charged in the coke dry fire extinguishing equipment 10 by utilizing the pressure difference between the circulating gas and the atmosphere. The intake port 27 that naturally sucks air, the air fan 28 that forcibly sucks air, and the amount of air introduced via the air inlet tube 31 via the intake port 27 or the air fan 28 are converted into the combustion gas in the circulating gas. An air introduction means 25 having a flow rate adjusting valve 29 that adjusts according to the concentration of the gas is attached, and in the process in which the concentration of the combustion gas decreases from the concentration during steady load operation, the air introduction means 2 In the process in which the air fan 28 is stopped and the on-off valve 26 provided with the intake port 27 is opened to naturally suck air, and the concentration of the combustion gas increases toward the concentration during steady load operation, The on-off valve 26 provided at the intake port 27 is closed and the air fan 28 is operated to forcibly introduce air. Details will be described below.

When the coke oven is in a steady load operation state, as shown in FIG. 5 (A), the circulating gas in the pre-chamber 22 is mixed with a certain amount of combustion gas every time when the red hot coke is charged. The concentration value of the combustion gas in the circulating gas in the ring duct 24 measured by the densitometer is substantially constant. For this reason, as shown in FIG. 5 (B), the required air amount obtained by the valve opening setting unit is constant, and the air introduction switching determining unit introduces the necessary air amount into the ring duct 24 to the drive unit. As shown in FIG. 5 (C), the command signal is output, and the on / off valve 26 is closed and the air fan 28 is operated (ON), and the flow rate adjusting valve 29 is opened as shown in FIG. 5 (D). The degree is adjusted to a constant value.

When the coke oven changes to the minimum load operation state, as shown in FIG. 5 (A), the amount of red hot coke charged to the CDQ 10 from the coke oven rapidly decreases, so the coke oven has entered the minimum load operation state. When time elapses, the concentration of the combustion gas in the circulating gas in the ring duct 24 measured by the combustion gas concentration meter starts to decrease. For this reason, as shown in FIG. 5 (B), the required air amount calculated by the valve opening setting unit gradually decreases, so the command for the flow rate control valve 29 output from the valve opening setting unit to the drive unit. With the signal, as shown in FIG. 5D, the valve opening degree of the flow control valve 29 gradually decreases. If the air introduction switching determination unit determines that the required air amount exceeds the natural suction air amount even when the concentration of the combustion gas decreases and the required air amount decreases, FIG. ), The air fan 28 is continuously operated.

As more time elapses after the coke oven reaches the minimum load operation state, as shown in FIG. 5 (A), the concentration of the combustion gas in the circulating gas measured by the combustion gas concentration meter further decreases. As shown in FIG. 5 (B), the required air amount calculated by the valve opening setting unit based on the concentration of the combustion gas is determined by the pressure of the circulating gas and the atmospheric pressure in the ring duct 24 measured by the gas pressure gauge. When the air introduction switching determination unit determines that the amount of natural suction air naturally sucked from the intake port 27 with the on-off valve 26 opened is determined using the pressure difference of FIG. As shown, the forced introduction of operating the air fan 28 by closing the on-off valve 26 is stopped, the air fan 28 is stopped, the on-off valve 26 is opened, and the natural suction of air through the intake port 27 is started.

When the air fan 28 is stopped and the on-off valve 26 is opened to start the natural suction of air through the intake port 27, first, the switching valve opening setting unit first performs combustion measured by a combustion gas concentration meter. The gas concentration, the inlet and outlet pressures measured by the inlet and outlet air pressure gauges arranged on both sides of the flow control valve 29, and the air temperature measured by the air thermometer, respectively. 3 is used to calculate the Cv value of the flow control valve 29, and based on the relationship between the Cv value and the valve opening of the flow control valve 29 shown in FIG. Set the degree. Next, a valve opening command signal set from the switching valve opening setting unit is input to the drive unit, and the valve of the flow rate adjustment valve 29 is operated. As a result, when the natural suction shown in FIG. 5 (B) is started, as shown in FIG. 5 (D), the valve opening degree of the flow rate control valve 29 changes to the set value.

As time passes after the supply of the required amount of air by the natural suction of air into the ring duct 24 is started, as shown in FIG. 5 (A), as the concentration of the combustion gas decreases, FIG. As shown in FIG. 5B, the required air amount determined by the valve opening setting unit is reduced, so that the valve opening of the flow rate adjusting valve 29 is also reduced as shown in FIG. As shown in FIG. 5 (A), when the concentration of the combustion gas becomes a constant value, as shown in FIGS. 5 (B) and 5 (D), the required air amount obtained by the valve opening setting unit becomes constant. The valve opening degree of the flow control valve 29 is also constant.

When the coke oven returns from the minimum load operation state to the steady load operation state, as shown in FIG. 5 (A), the amount of red hot coke charged into the CDQ 10 from the coke oven increases rapidly, so a combustion gas concentration meter is used. The concentration of the combustion gas in the circulating gas in the ring duct 24 thus measured starts to rise. For this reason, as shown in FIG. 5 (B), the required air amount calculated by the valve opening setting unit gradually increases, so that the flow control valve 29 output from the valve opening setting unit to the drive unit is used. With the command signal, as shown in FIG. 5D, the valve opening degree of the flow control valve 29 is gradually increased. In addition, even if the concentration of the combustion gas increases and the required air amount increases, if the air introduction switching determination unit determines that the required air amount is equal to or less than the natural suction air amount, FIG. As shown, the air fan 28 is in a stopped state.

As time elapses after the coke oven enters the steady load operation state, as shown in FIG. 5A, the concentration of the combustion gas in the circulating gas measured using the combustion gas concentration meter further increases. Then, as shown in FIG. 5 (B), the air introduction switching determination unit determines that the required air amount calculated by the valve opening setting unit based on the combustion gas concentration exceeds the natural suction air amount (that is, the gas concentration). In order to take in the necessary air amount calculated by the valve opening setting unit based on the concentration of the combustion gas measured by the meter, the natural suction through the intake port 27 is stopped and the air fan 28 is operated) When the determination is made, a command signal for operating the air fan 28 by closing the opening / closing valve 26 is output from the air introduction switching determination unit to the drive unit, the opening / closing valve 26 is closed, and as shown in FIG. The forced introduction is started by driving 28.

Here, when the on-off valve 26 is closed and the operation of the air fan 28 is started, first, in the switching valve opening degree setting unit, the concentration of the combustion gas measured by the combustion gas concentration meter and both sides of the flow rate control valve 29 are set. The Cv value of the flow control valve 29 is calculated using the inlet side pressure and the outlet side pressure measured by the inlet side air pressure gauge and the outlet side air pressure gauge, respectively, and the air temperature measured by the air thermometer. Then, the valve opening is set based on the relationship between the Cv value and the valve opening of the flow rate control valve 29 shown in FIG. Next, a valve opening command signal set from the switching valve opening setting unit is input to the drive unit, and the valve of the flow rate adjustment valve 29 is operated. As a result, when the forced introduction of the required air amount shown in FIG. 5 (B) is started, as shown in FIG. 5 (D), the valve opening degree of the flow control valve 29 changes to a set value.

As time passes after the supply of the required amount of air by forced introduction of air into the ring duct 24 is started, as shown in FIG. 5 (A), as the concentration of the combustion gas increases, FIG. As shown in (B), since the required air amount calculated by the valve opening setting unit increases, the valve opening of the flow control valve 29 also increases as shown in FIG. As shown in FIG. 5 (A), when the concentration of the combustion gas becomes a constant value, the required air amount calculated by the valve opening setting unit is also constant as shown in FIGS. 5 (B) and 5 (D). Thus, the valve opening degree of the flow control valve 29 is also constant.

As described above, when the required amount of air is supplied into the ring duct 24, when switching from natural suction to forced introduction, the valve opening degree of the flow control valve 29 is set based on the Cv value of the flow control valve 29. Then, the valve opening degree corresponding to the required air amount is set in advance after switching, and as shown in FIG. 6 (A), in the air introducing means 25 (in the air flow path) generated at the time of switching the air introducing method. It is possible to minimize the delay in the response of the flow control valve 29 due to the sudden pressure fluctuation, and to reliably introduce the required air volume.

On the other hand, when switching from natural suction to forced introduction as in the prior art, when setting the valve opening of the flow control valve based on the required air amount, as shown in FIG. The response delay of the flow rate control valve 29 due to a sudden pressure fluctuation in the air introduction means (in the air flow path) is increased, and immediately after switching, an area where the required air volume cannot be introduced is an area where the air volume is too low. After an excessive air volume region where air exceeding the required air volume is introduced is generated, it becomes an area where air of the required air volume is introduced.

As a result, in the present embodiment, the concentration of the combustion gas in the circulating gas can be more accurately controlled, which can contribute to the safe and stable operation of the coke dry fire extinguishing equipment. Furthermore, it is possible to accurately control the concentration of the combustion gas in the circulating gas, prevent an increase in the oxygen concentration in the circulating gas, and the high temperature of the metal member exposed to the circulating gas in the coke dry fire extinguishing equipment 10. Oxidative corrosion can be prevented, and stable operation of the coke dry fire extinguishing equipment 10 can be further promoted.

Furthermore, if the concentration of combustion gas increases during the natural suction of air and the required amount of air exceeds the amount of natural suction air, the natural suction is stopped and forced introduction is started. When the required air volume falls below the natural suction air volume and the forced introduction is stopped and the natural suction is started, the operator may, for example, respond to fluctuations in the charging amount of red hot coke or the circulating gas. Compared with the case where the air introduction method is changed according to the concentration fluctuation of the combustion gas in the inside, the judgment of switching the air introduction method can be made uniformly, and the operation of the coke dry fire extinguishing equipment 10 can be stabilized. Is possible.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.
Further, the present invention also includes a combination of components included in the present embodiment and other embodiments and modifications.

10: Coke dry fire extinguishing equipment, 11: cooling chamber, 12: primary duct, 13: waste heat recovery boiler, 14: secondary duct, 15: charging device, 16: primary dust catcher, 17: dust discharging device, 18: secondary dust catcher, 19: gas circulation fan, 20: feed water preheater, 21: coke discharge device, 22: pre-chamber, 23: cooling chamber, 24: ring duct, 25: air introduction means, 26: on-off valve 27: Intake port, 28: Air fan, 29: Flow control valve, 30: Flow meter, 31: Air introduction pipe

Claims (3)

In the introduction control method of combustion air in the coke dry fire extinguishing equipment, which introduces air for burning the combustion gas contained in the circulating gas into the circulating gas flowing into the waste heat recovery boiler of the coke dry fire extinguishing equipment,
A cooling chamber that receives and cools reddish coke charged in the coke dry fire extinguishing equipment, naturally sucks air using a pressure difference between the circulating gas and the atmosphere, and an air fan that forcibly introduces air And an air introduction means comprising a flow rate adjusting valve for adjusting the amount of air introduced through the intake port or the air fan according to the concentration of the combustion gas in the circulating gas,
In the process in which the concentration of the combustion gas is lower than the concentration at the time of steady load operation, the air fan of the air introduction means is stopped and the intake port is opened to naturally suck air, and the concentration of the combustion gas is the steady load. Combustion air introduction control in a coke dry fire extinguishing system, wherein the air inlet is closed and the air fan is operated to forcibly introduce air in the process of increasing toward the concentration during operation Method. In the method for controlling the introduction of combustion air in the coke dry fire extinguishing equipment according to claim 1, when switching from the forced introduction to the natural suction or from the natural suction to the forced introduction, the valve opening degree of the flow rate control valve, Coke dry fire extinguishing, which is set based on an air amount necessary for combustion of the combustion gas and a capacity coefficient of the flow rate control valve calculated using an inlet side pressure and an outlet side pressure of the flow rate control valve Introduction control method of combustion air in equipment. The method for controlling the introduction of combustion air in a coke dry fire extinguishing system according to claim 1 or 2, wherein the concentration of the combustion gas increases during the natural suction of air, and the amount of air necessary for combustion of the combustion gas is When the amount of natural suction air determined by the pressure difference is exceeded, the natural suction is stopped and the forced introduction is started. At the time of forced introduction of air, the concentration of the combustion gas decreases, and is necessary for combustion of the combustion gas. A combustion air introduction control method in a coke dry fire extinguishing system, wherein when the air amount becomes equal to or less than a natural suction air amount determined from the pressure difference, the forced introduction is stopped and the natural suction is started.

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