JPH07166165A - Control method of coke oven pressure - Google Patents

Abstract

(57) [Summary] [Purpose] To control the internal pressure of a coke oven consisting of multiple combustion chambers and carbonization chambers with high accuracy. [Structure] When performing program heating control for each carbonization chamber in a coke oven, the flow passage area of combustion exhaust gas is calculated using the following characteristic expression, and each combustion chamber 3 is calculated based on the flow passage area. The opening degree of the combustion chamber pressure control damper 16 is determined. [Equation 6]

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a furnace pressure control method for a coke oven in which a plurality of combustion chambers and carbonization chambers are arranged.

[0002]

2. Description of the Related Art Coke ovens conventionally used are
A plurality of carbonization chambers and combustion chambers are alternately arranged so that both sides of the carbonization chamber are sandwiched by the combustion chambers. Then, combustion gas and air are supplied to the respective combustion chambers, the carbonization chamber sandwiched between the combustion chambers is heated, and the coal filled in the carbonization chamber is carbonized to generate coke.

The control of combustion in this conventional coke oven is performed by controlling the flow rates of the fuel gas and air supplied to the entire coke oven to a constant flow rate, and the combustion gas and air of each combustion chamber are controlled. The flow rate was not controlled automatically. That is, the furnace internal pressure of the combustion chamber is detected at the representative position of the coke oven in units of the furnace group, and the opening degree of the damper provided in the flue is adjusted so that the detected furnace internal pressure becomes a predetermined appropriate value.

[0004]

However, when the programmed heating control for each carbonization chamber of the coke oven is performed, the flow rates of the fuel gas and the air supplied to each combustion chamber change greatly with time, which is a conventional problem. It is impossible to keep the in-furnace pressure in each combustion chamber at a constant value by controlling the pressure of each furnace group. If the pressure inside the combustion chamber of the coke oven cannot be maintained at an appropriate value, it will seriously hinder the operation of the coke oven. That is,
When the pressure inside the combustion chamber becomes higher than the proper value, the fuel gas is discharged from the fuel gas supply system, and it becomes a very dangerous state in the work environment.When it becomes lower than the proper value, air enters the combustion chamber and the furnace body Result in damage.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art. The object of the present invention is to provide a coke oven having a plurality of combustion chambers and carbonization chambers arranged in a row. It is to accurately control the furnace pressure of each combustion chamber when performing the programmed heating for each carbonization chamber.

[0006]

In order to achieve the above-mentioned object, a plurality of rows of carbonization chambers for carbonizing carbon to form coke and combustion chambers for heating the carbonization chambers are alternately provided in each combustion chamber. Is connected to a fuel gas supply passage for supplying fuel gas, an air supply passage for supplying air, and an exhaust gas passage for discharging combustion exhaust gas, and a fuel gas flow rate adjusting valve is provided in the fuel gas supply passage, An air flow rate adjustment valve is installed in the air supply path,
In the program heating control for each carbonization chamber of the coke oven in which the combustion chamber pressure control damper is provided in front of the combustion exhaust gas change valve in the exhaust gas passage, the flow rate of fuel gas and the flow rate of air supplied to each combustion chamber are detected. The exhaust gas flow rate (W) is calculated by the following method, and the furnace top pressure (P _TOP ) and flue damper pre-pressure (P
_The flow coefficient (S) of the combustion exhaust gas is calculated based on the differential pressure of ( _DRF ) and the exhaust gas flow rate (W), and when the opening of the combustion chamber pressure control damper for each combustion chamber is adjusted, the flow coefficient ( α)
Is characterized by determining the opening degree of the combustion chamber pressure control damper for each combustion chamber by the following characteristic equation expressed as a quadratic equation with the flow passage area (S) of the combustion exhaust gas as a variable.
The characteristic formula is represented by the following formula.

[Equation 2]

Further, by learning the control parameters (a, b, c) of the quadratic equation having the flow passage area (S) of the combustion exhaust gas as a variable, which expresses the flow coefficient (α), at an arbitrary fixed cycle. The characteristic expression is modified to determine the opening of the combustion chamber pressure control damper for each combustion chamber.

[0008]

Since the present invention has the above-mentioned structure, it operates as described below. In the invention according to claim 1, the exhaust gas flow rate of the combustion exhaust gas changing valve is defined by a characteristic expression

[0009]

[Equation 3]

It is represented as.

Then, the flow passage area (S) of the combustion exhaust gas is calculated using the above-mentioned characteristic formula, and the opening of the combustion chamber pressure control damper for each combustion chamber is calculated based on the flow passage area (S). decide. In each combustion chamber, the pressure inside the combustion chamber is controlled by setting the combustion chamber pressure control damper to the determined opening. That is, first, the exhaust gas flow rate (W) of the combustion exhaust gas change valve is calculated as the total of the fuel gas flow rate and the air flow rate which are drawn to the combustion exhaust gas change valve. Next, the flow passage area (S) of the combustion exhaust gas is expressed by the characteristic equation

[0012]

[Equation 4]

On the other hand, the target value of the top pressure (P _TOP ) of the combustion chamber and the set value (constant value) of the pressure before flue damper (P _DRF ) are given, and the cubic equation of S is given by Newton-Rap.
It is obtained by solving by a numerical solution method such as the hson method. Generally, since there is a correlation between the flow passage area (S) and the opening degree, the combustion pressure control damper opening degree can be obtained from the flow passage area (S) by a relational expression obtained in advance. By setting this opening, the furnace top pressure (P _TOP ) in the combustion chamber is controlled to the target value.

According to the second aspect of the invention, the flow coefficient (α) is a variable of the flow passage area (S) of the combustion exhaust gas.
The control parameter (a,
b, c) are obtained and learned in an arbitrary fixed cycle to correct the characteristic formula to determine the opening degree of the combustion chamber pressure control damper for each combustion chamber.

Therefore, it is possible to cope with a change in characteristics, and it is possible to perform highly accurate furnace pressure control for each combustion chamber. This learning function works only when the operating conditions of the coke oven, such as changes in the operating rate and fuel gas properties, change and this characteristic changes, and does not work when the operating conditions of the normal coke oven do not change. You can take the method.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an outline of a coke oven according to the present invention, and FIG. 2 is an explanatory diagram showing a relationship between a flow coefficient (α) and a flow passage area (S) of combustion exhaust gas. FIG. 3 is a transition diagram of the exhaust gas flow rate of the combustion exhaust gas changing valve, the combustion chamber pressure control damper opening, and the combustion chamber furnace top pressure when the present control method is applied to a coke oven that performs program heating control.

As shown in FIG. 1, a coke oven 1 according to the present invention has a plurality of carbonization chambers 2 for carbonizing carbon to be coke and a plurality of combustion chambers 3 for heating the carbonization chamber 2 alternately in the lateral direction. A fuel gas supply path 4 for supplying a fuel gas, an air supply path 5 for supplying an air, and an exhaust gas flow path 6 for discharging a combustion exhaust gas are connected to each combustion chamber 3 in a row. A fuel gas flow rate adjusting valve 7 is provided in the supply passage 4, and an air supply passage 5 is provided.
An air flow rate adjusting valve 8 is provided in the exhaust gas flow path 6, and a combustion chamber pressure control damper 16 is provided in front of the combustion exhaust gas changing valve 9 in the exhaust gas passage 6.

A heat storage chamber 10 is provided below each combustion chamber 3. The heat storage chamber 10 guides the fuel and air to be supplied to the combustion chamber 3 and also guides the combustion exhaust gas generated by the combustion to the flue 11. Therefore, the inside of the heat storage chamber 10 is heated by the high-temperature combustion exhaust gas, so that the heat can preheat the fuel and the air supplied to the combustion chamber 3, and the combustion efficiency of the fuel can be improved.

Further, a furnace group air amount adjusting valve 13 is provided in the air supply main 12 for supplying air to each air supply passage 5, and the fuel gas supply for supplying fuel gas to each fuel gas supply passage 4 is provided. The main tube 14 is provided with a reactor fuel gas flow rate adjusting valve 15. Further, the exhaust gas passages 6 provided for each combustion chamber 3 are collected to form a flue 11, which communicates with a chimney (not shown).

The combustion chamber pressure control damper 16 is provided with an opening / closing mechanism (not shown) so that the opening degree of the combustion chamber pressure control damper 16 can be automatically changed. The opening / closing mechanism of the combustion chamber pressure control damper 16 is, for example, an actuator, and is electrically controlled by a process computer (not shown) to adjust the opening degree of the combustion chamber pressure control damper 16.

The procedure of coke generation in the above coke oven 1 will be described. First, preheated coal (powdered coal) is supplied to the carbonization chamber 2. Air is supplied to the combustion chamber 3 from the air supply passage 5 and fuel gas is supplied from the fuel gas supply passage 4 to burn in the combustion chamber 3, and the carbonization chambers 2 adjacent to each other are installed.
Is heated. The combustion gas supplied to the combustion chamber 3 is a mixture of coke oven gas and blast furnace gas having different calories.

Then, the exhaust gas flow rate (W) of the combustion gas changing valve, the furnace top pressure (P _TOP ) of the combustion chamber 3 and the flue damper pre-pressure (P _DRF ) are set as set values, and a characteristic equation is set.

[0023]

[Equation 5]

By substituting into the flow path area (S) of the combustion gas, and based on the calculated flow path area (S), each combustion chamber 3
The opening degree of each combustion chamber pressure control damper 16 is determined. The flow passage area (S) and the opening degree of the combustion chamber pressure control damper 16 generally have a constant correlation, and if the correlation is obtained in advance by actual measurement, the flow passage area (S) is burned. It can be converted into the opening degree of the chamber pressure control damper 16.

Based on the opening of the combustion chamber pressure control damper 16 thus obtained, in each combustion chamber 3, the actuator is electrically controlled by the process computer to adjust the opening of the combustion chamber pressure control damper 16. It

In the above characteristic equation, the flow coefficient can be expressed by a quadratic equation in which the flow passage area (S) of the combustion exhaust gas is a variable. Therefore, the exhaust gas flow rate (W) of the combustion gas change valve, the flow passage area (S) of the combustion exhaust gas, and the combustion detected by the combustion chamber pressure detection sensor 17, which are the actual values when the coke oven 1 is actually operated. Top pressure of chamber 3 (P
_TOP ) and the flue damper pre-pressure (P _{DR F} ), the control parameter (a, b, c) of the above-described quadratic equation is obtained, and this control parameter is learned in a predetermined constant cycle. For example, data is captured for 24 hours in accordance with the switching of the combustion exhaust gas change valve every 30 minutes. That is, data of 48 points for one day is used.

FIG. 2 shows an example based on the measured values of the above-mentioned quadratic equation. In this quadratic equation, the control parameters of the flow coefficient are a = 1842, b = 3095, and c = 2402, respectively.

FIG. 3 shows an embodiment in which the present control method is applied to a coke oven which performs program heating control. As shown in FIG. 3, the combustion chamber pressure control damper opening 16 calculated by the present control method is set for the exhaust gas flow rate of the combustion exhaust gas change valve 9 that greatly changes with time by the program heating control, thereby Chamber furnace top pressure target value ± 2 mmA
It was possible to control accurately within q.

[0029]

Since the present invention is configured as described above, the following effects can be obtained. In the invention according to claim 1, the flow passage area (S) of the combustion exhaust gas is calculated using the characteristic expression, and the opening of the combustion chamber pressure control damper for each combustion chamber is calculated based on the flow passage area (S). To decide. In each combustion chamber, the pressure inside the combustion chamber is controlled by setting the combustion chamber pressure control damper to the determined opening.

By setting the furnace pressure to an appropriate value, damage to the furnace body of the coke oven can be prevented, and repair of the furnace body can be minimized. Further, discharge of fuel gas from the fuel gas supply system can be prevented, and coke oven work can be performed in a safe environment.

According to the second aspect of the present invention, the flow coefficient is expressed as a quadratic equation in which the flow passage area of the flue gas is used as a variable, and the control parameter of the quadratic equation is obtained and learned at an arbitrary fixed cycle. Thus, the characteristic equation is corrected to determine the opening of the combustion chamber pressure control damper for each combustion chamber.

Therefore, it is possible to cope with a change in characteristics, and it is possible to perform highly accurate furnace pressure control for each combustion chamber.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an outline of a coke oven according to the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a flow coefficient and a flow passage area of combustion exhaust gas.

FIG. 3 is a transition diagram of an exhaust gas flow rate of a combustion exhaust gas changing valve, a combustion chamber pressure control damper opening, and a combustion chamber pressure according to the control method of the present invention.

[Explanation of symbols]

 1 Coke Oven 2 Carbonization Chamber 3 Combustion Chamber 4 Fuel Gas Supply Path 5 Air Supply Path 6 Exhaust Gas Flow Path 7 Fuel Gas Flow Rate Control Valve 8 Air Flow Rate Control Valve 9 Combustion Exhaust Gas Change Valve 10 Heat Storage Room 11 Flue 12 Air Supply Mains 13 Reactor group air flow rate control valve 14 Fuel gas supply main 15 Reactor group gas flow rate control valve 16 Combustion chamber pressure control damper 17 Combustion chamber pressure detection sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Sato 1-1 Tobata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka Inside Nippon Steel Corporation Yawata Works

Claims (2)

[Claims] 1. A carbonization chamber in which coal is carbonized to coke.
A plurality of rows of combustion chambers for heating the carbonization chamber are alternately provided, and each combustion chamber has a fuel gas supply path for supplying a fuel gas,
An air supply path for supplying air and an exhaust gas flow path for discharging combustion exhaust gas are connected, a fuel gas flow rate adjusting valve is provided in the fuel gas supply path, and an air flow rate adjusting valve is provided in the air supply path. In the program heating control for each coking chamber of a coke oven that has a combustion chamber pressure control damper in front of the combustion exhaust gas change valve in the flow path, the exhaust gas is detected by detecting the flow rate of fuel gas and air flow rate supplied to each combustion chamber. The flow rate (W) is calculated, and the flow area (S) of the combustion exhaust gas is calculated based on the differential pressure between the furnace top pressure (P _TOP ) and the flue damper front pressure (P _DRF ) in the combustion chamber and the exhaust gas flow rate (W). And the flow coefficient (α) is a quadratic expression in which the flow passage area (S) of the combustion exhaust gas is used as a variable when adjusting the opening of the combustion chamber pressure control damper for each combustion chamber. Combustion chamber pressure control damper for each combustion chamber A method for controlling the internal pressure of a coke oven, which is characterized in that the opening degree of the coke oven is determined. [Equation 1] 2. The method for controlling the internal pressure of a coke oven according to claim 1, wherein the flow area (S) of the combustion exhaust gas, which represents the flow coefficient (α),
Control parameters (a, b, c) of quadratic equation with variable
A method for controlling the internal pressure of a coke oven, characterized in that the opening degree of the combustion chamber pressure control damper for each combustion chamber is determined by modifying the characteristic equation by learning at a given constant cycle.