JPS6389587A - Method for measuring flow rate of coke oven fuel gas - Google Patents

Abstract

PURPOSE:To effectively conduct combustion control through lowering in the variation in the carbonization between carbonization chambers and an improvement in the combustion efficiency within the carbonization chamber, by measuring the amt. influent combustion air and the composition an influent fuel gas for each combustion chamber. CONSTITUTION:A measuring box 12 accommodating an anemometer 9, a thermometer 10, and a hygrometer 11 is abutted against an inlet of combustion air, and an air flap is opened to close a damper 14 for a flue 6. Air is passed from an influent side B through the box 12, a discharge side A, and an opening 15 of the flap 3 to detect the flow rate and determine the amt. of the inflow air, while the theoretical amt. of combustion air and that of combustion waste gas are calculated from the composition of the combustion gas. Separately, the amt. of excess air is computed from the concn. of the O2 CO contained in the combustion waste gas to determine the amt. of combustion air per unit fuel gas. The amt. of the fuel gas is detected based on the amt. of combustion air and the amt. of inflow air.

Description

[Detailed description of the invention] <Object of the invention> Industrial field of application The present invention relates to a method for measuring a coke oven fuel gas flow field.
Specifically, the present invention relates to a method for measuring fuel gas outflow in a coke oven in which combustion air is introduced by natural ventilation.

As is well known, a conventional coke oven has a heat storage chamber in the lower part of the furnace body, a carbonization chamber in the upper part, and a combustion chamber for heating the carbonization chamber. The combustion air and fuel gas (if poor gas is used) are preheated in the heat storage chamber, and after combustion, the heat is recovered in the heat storage chamber in contact with the VA, and then the flue is lightened. is being discharged.

The operation of this coke oven is based on the target carbonization temperature and the actual output of the fuel gas supplied to the combustion chamber across the carbonization chamber to heat the combustion chamber, the combustion air, and the exhaust gas discharged during the first combustion stage. The carbonization temperature is adjusted to match the carbonization temperature, and the coal charged in the carbonization chamber is heated and carbonized indirectly through a refractory that partitions the combustion chamber and the carbonization chamber, until the charged coal becomes coke. The fire-off time and the standing time from fire-off to coke extrusion are approximately equal to the turning time for each carbonization weight.

The wind in such a combustion is flll tlfl,
A simple control scheme is implemented to adjust the suction draft pressure.

However, the structure of a coke oven is complicated, and it is extremely difficult to control carbonization, and although many attempts have been made in the past, they have only been carried out by trial and error.

This is due to the fact that the difference in the flow rates of fuel gas and introduced air between the combustion chambers and the inability to know the introduced fuel gas and air flow rates.

In order to eliminate this difference in flow rate, JP-A-51-19
There are technical means described in No. 8783 and Japanese Unexamined Patent Publication No. 58-38784, and the former installs a nozzle tip on a branch pipe reaching each combustion chamber, making it possible to supply an appropriate amount of gas to each combustion chamber. In other words, it is possible to improve the flow process of the introduced gas and stabilize the flow ratio of the supplied gas and air, respectively. U has been proposed.

However, due to changes over time, operational changes, etc., these values fluctuate, and in coke ovens that have many combustion chambers, it is extremely difficult to maintain a constant combustion condition between these combustion chambers over a long period of time. In the end, it is customary to continue operating the coke oven by averaging the temperature within the combustion chamber by measuring the temperature, and by reducing the variation in the fire-off time in the coking space by using the fire-off determining means, and by using these various methods. Try it! The reality is that people are trying to achieve proper combustion conditions by repeatedly making adjustments incorrectly.

Therefore, if the flow m of fuel gas and air introduced into the combustion chamber could be determined from the above problem, it would be a great step forward in solving this problem. Methods of measuring failure, such as a stop meter, had the following problems and could not be achieved.

(1) Due to equipment issues such as furnace structure and installation space,
There is no place to install fuel gas and air flow meters.

(2) Even if a flow meter was installed, it would be impossible to provide a sufficient straight pipe length upstream of the flow m needle installation point d, which is necessary to ensure measurement accuracy with a 1fl meter, and aging This tends to occur, making it impossible to obtain sufficient measurement accuracy and reliability.

(3) Furthermore, in order to install a fuel gas flow meter in each combustion chamber, lX1iI! It is necessary to install a large number of i FQ hanging meters (for example, in a coke oven with 88 combustion chambers per furnace group, the total of C3 and MS per furnace group is 88X2 =
176 flow meters must be installed), and the equipment cost is extremely high.

For the above reasons, although the need is very high,
There was no effective measurement method.

In order to effectively manage combustion in a coke oven, it is necessary to know the flow rate of fuel gas and air flowing into each coking chamber and to control the C loss. However, in reality, there is no way to know the flow rate; (1) a method and device for measuring the combustion air flow rate for each air exhaust valve; (2) measurement of the combustion air flow rate and fuel gas composition. Therefore, a method of determining and quantifying the fuel gas inflow W for each combustion chamber is an essential requirement for achieving the purpose of the invention.

Problems to be Solved by the Invention The present invention aims to solve these problems. Specifically, the present invention aims to solve the problems described above. The purpose is to provide a method for measuring 1.

<Structure of the Invention> Means for Solving the Problems and Their Effects The present invention detects the flow velocity of the introduced air by abutting a measuring box containing an anemometer, a thermometer, and a hygrometer against the inlet of combustion air. In addition to determining the inflow air amount, the theoretical combustion air amount and theoretical combustion waste gas amount are calculated from the composition of the fuel gas. On the other hand, the excess air amount is estimated from the 02 and GO concentration in the combustion part gas, the combustion air per unit fuel gas is determined, and the fuel gas amount is detected based on the air amount and the inflow air amount. Hereinafter, the structure and operation of the means of the present invention will be explained with reference to the drawings.

FIG. 1 is a side view illustrating the measuring method according to the present invention, FIGS. 2(a) and (b) are a cross-sectional view and a longitudinal sectional view of a measuring box for introducing air flow velocity, and FIG. (a) and (b) are graphs showing changes over time in the combustion air flow rate in Examples, respectively.

First, the measurement method according to the present invention applies to natural draft coke ovens, such as Karl Steel type, Copperce type,
Applicable to Otto type and other coke ovens.

In the present invention, an anemometer capable of measuring the flow velocity of the introduced air is installed in the introduction section of the combustion air taken in by this natural ventilation method, and the flow rate of the incoming air is first determined.

FIG. 2 shows a measuring device for the flow rate of introduced air. has a discharge side A in contact with the air introduction part of the coke oven and an air inflow side B, and the discharge side A has a shape that is in close contact with the opening surface 15 (see Fig. 1) when the air flap 3 of the coke oven is opened. It has an anemometer 9 inside.
is provided.

The anemometer 9 is preferably an ultrasonic anemometer to measure the flow velocity of the introduced air. The measurement box 12 is composed of a frame consisting of a top plate, a bottom plate, and a side plate,
The side plate may have a channel width adjustment function to adapt to the furnace type.

By measuring the flow velocity of the air flowing inside the frame using the anemometer 9, the inflowing air can be determined based on the cross-sectional area of the frame. Reference numerals 10 and 11 indicate a thermometer and a hygrometer, through which the incoming air on a dry basis converted to a standard condition is discharged.

The advantages of the ultrasonic anemometer are as follows.

(1) High accuracy in measuring wind direction. (The wind velocity component in any direction can be determined.) Since the flow rate must be calculated based on the flow velocity in the cross-sectional direction of the channel, the accuracy of measuring the wind direction depends on the accuracy of the outflow.

(2) High accuracy in measuring flow velocity.

The sensor's detectable flow rate resolution ability is 0.01 m/s
It has a speed detection capability h (10 times or more than propeller type or hot wire type).

Fig. 1 shows a situation in which the flow rate of introduced air is measured using the measuring device 1 shown in Fig. 2. In order to introduce combustion air, the measuring device 1 is placed on the opening surface with an air flap 3 in between. Measure by touching.

At this time, naturally, the damper 14 to the flue 6 is closed. Since the measuring device 1 is mounted on the mobile lifter 4, by performing this measurement for each of the many adjacent air exhaust valves 2, it is possible to determine the air ω introduced into each carbonization chamber unit. . 7 and 8 indicate anemometer transducers and recorders. Furthermore, during the above measurement, the opening degree of O7 and CO of the combustion exhaust gas is measured.

The procedure for measuring fuel gas outflow will be explained below.

(1) The average flow velocity 11 or center flow velocity U2 of combustion air at the inlet of the coke oven air exhaust valve is measured using the apparatus shown in FIG. 2 (the measuring method is shown in FIG. 1).

(21) Calculate the amount of incoming air v^ using equation (1) (or equation (1)') using the air flow velocity U1 (or O2) measured in (11) and the cross section fI!lS of the frontage of the measuring device that has been measured in advance. do.

VA = α, ・U, ・S ・・・・・・(1) (VA
= cx2- L+2・Sl -------m' However, α1, α2: Flow rate molecule li correction coefficient (-) vA: Inflow air amount for each combustion chamber (m11'5IIJ, (U21: Air flow rate (m/ s) S: Opening cross-sectional area (m2) (3) On the other hand, based on the composition of the fuel gas, the theoretical combustion aerodynamics A and the theoretical combustion exhaust gas flow rate IGn are outputted through a combustion meter port. This combustion meter port is known in the art. It can be done by two people.

(4) Furthermore, 02 and CO concentration in waste gas and 11G
Determine the excess air amount A from O, and calculate the combustion air flow rate per unit fuel gas ^=^, 1 An from A1 and AO.

This excess air amount A can be determined by knowing the air ratio m using equation (2).

Analysis of combustion gases using 1ifl and fuel composition.

To 0.21.

Furthermore, if m is used, it goes to A-A, + mentioned above. is mAo-A
It can be done.

(5) The relationship between the fuel gas flow rate Va and vA for each combustion chamber is V, = VA i'A --------- (3), so using equation (3), calculate the fuel gas flow from VA and 8. Gas'am
Calculate Vo.

As explained above, the present invention was developed for the purpose of practical use of a method for quantifying fuel gas and air outflow from each combustion chamber of a coke oven in which combustion air is introduced by natural draft. All the technical problems mentioned above have been resolved.

In other words, (1) The measurement method is simple, and? Since the il measuring device is lightweight and compact, there is no need to take special consideration of equipment space and the like.

(2) Since the inflow air flow rate for each exhaust valve is measured with one measuring device, there is no need to take into account instrumental differences between measurement devices, and the cost of setting the device and maintenance costs are low.

(3) Measurement accuracy is not limited to simply knowing the relative value of the air outflow for each exhaust valve, as was attempted in the past, but it is also possible to measure the absolute value and adjust the flow velocity distribution correction coefficient appropriately. By setting it to , high measurement accuracy can be achieved.

Waiting for features such as.

Example This will be further explained below using examples.

Figure 3 shows the results of measuring the combustion air outflow using a main flow clarification measuring device in the Honjima & 5 coke oven.

Figure 3 shows the operating vJ rate of 120% and the waste gas 0□waterfall degree of 2.69.
This is the data for the 4th combustion cycle at time 6, and the inflow air and fuel gas flow rate at this time were as shown in Table 1.

Table 1 Note that the outflow fluctuates in Figure 3 because it is affected by flue draft control.

<Effects of the Invention> As explained above, the present invention brings a measuring box containing an anemometer, a quality meter, and a hygrometer into contact with the combustion air inlet, detects the flow velocity of the incoming air, and detects the incoming air. In addition to determining the amount, the theoretical combustion air amount and 1'll! are determined from the composition of the fuel gas.
Calculate the theoretical combustion waste gas field. On the other hand, 02 in the combustion waste gas
The method is characterized in that the excess air product is determined from the degree of C0=a, the amount of combustion air per unit of fuel gas is determined, and the amount of fuel gas is detected based on the amount of air and the inflow air intoxication. This is a method for measuring coke oven combustion gas outflow, and it is difficult to quantitatively grasp the flow rate of fuel gas and air in each coke oven combustion chamber by the method of the present invention, which has traditionally been a problem due to variations in carbonization between carbonization chambers. In addition to reducing combustion efficiency and improving the combustion efficiency in the coking chamber, it will be essential in the future when implementing program heating, etc., and will have a very large effect as a point of view for effective combustion management in coke ovens. can be expected.

Note that the present invention is highly versatile, as it is possible to quantify the furnace gas flow rate with the same device during both M gas and C gas combustion.

[Brief explanation of the drawing]

Fig. 1 is a side view of the equipment for carrying out the measurements according to the present invention, Figs. 2(a) and tb) are cross-sectional views and vertical sectional views of the measuring box for the inlet air flow rate, and Fig. 3! a i +tj
and (old) are graphs showing changes over time in the combustion air flow rate in the Chichi example.
... Air supply valve 3 ... Air flap 4 ... Mobile lifter 5 ... Coke oven heat storage chamber 6 ... Coke oven flue 1 ... ... Wind direction and speed meter converter 8 ... Recorder 9 ... Wind direction and speed meter 10 ... Thermometer 11 ...; ω
Minute meter 12...Measurement box

Claims (1)

[Claims] A measurement box containing an anemometer, a thermometer, and a hygrometer is placed in contact with the combustion air introduction section to detect the flow velocity of the introduced air to determine the amount of incoming air, and also to determine the theoretical combustion air amount and theoretical combustion based on the composition of the fuel gas. Calculate the amount of waste gas. On the other hand, the excess air amount is calculated from the O_2 and CO concentration in the combustion waste gas,
A method for measuring a coke oven fuel gas flow rate, characterized in that the amount of combustion air per unit fuel gas is determined, and the amount of fuel gas is detected based on the amount of air and the amount of incoming air.