Pressure control system for gas collecting pipe of coke oven

Abstract

The utility model relates to a coke oven gas collecting pipe pressure control system which comprises a first coke oven carbonization chamber and a second coke oven carbonization chamber, the second coke oven carbonization chamber and the first coke oven carbonization chamber are communicated with one end of a gas collecting pipe through pressure control pipes, and the other end of the gas collecting pipe is communicated with one end of a gas-liquid separator; the pressure control pipe is used for controlling the amount of air entering the air collecting pipe, so that the pressure of the air collecting pipe is kept within a preset range; the other end of the gas-liquid separator is communicated with the input end of the primary cooler set, the output end of the primary cooler set is communicated with one end of the fan through a pipeline, the pipe wall of the pipeline is provided with a fan front control butterfly valve, and the other end of the fan is provided with a gas purification device. According to the utility model, the fan front control butterfly valve is arranged at the front end of the fan, and the oven gas suction pipe butterfly valves are arranged in the gas collecting pipes of the first coke oven carbonization chamber and the second coke oven carbonization chamber, so that the gas inlet amount of the gas collecting pipes is controlled, and the pressure of the gas collecting pipes can be kept within a preset range, thereby improving the stability of the system.

Description

TECHNICAL FIELD

[0001] The utility model relates to coke oven collecting pipe pressure control technical field, especially a kind of coke oven collecting pipe pressure control system. BACKGROUND

[0002] The function of coke oven collecting pipe is to collect the gas guided from each carbonization chamber, which is recycled by fan after cooling. The pressure of collecting pipe is an important control index affecting coke quality, gas production and coke oven life. If the pressure of collecting pipe is too low, carbonization chamber will suck in air, causing coke combustion, affecting the life of furnace body, reducing coke quality, and even endangering the safe operation of air blower. If the pressure is too high, it will cause coke oven to smoke and fire, polluting the environment and wasting a lot of energy, and the ignition will reduce the heat intensity of furnace column and shorten the life of furnace.

[0003] The existing collecting pipe pressure control system still has the following technical problems when in use:

[0004] The current coke oven is TJL5550D ramming type, and the gas fan is selected as 1400Nm 3 / min. According to the production situation, when the fan operates at power frequency, the fan capacity is greatly surplus, and a large amount of capacity is wasted on the throttle valve, causing waste of electricity and extremely uneconomical operation. At the same time, due to the implementation of high-pressure ammonia water coal charging smoke reduction process in coke oven, the original collecting pipe pressure control system controls the pressure of coke oven collecting pipe through the operating power of fan, which has poor adjustment capacity, resulting in serious smoke phenomenon of coke oven. INVENTION CONTENTS

[0005] To solve the above problems, the purpose of the embodiment of the utility model is to provide a coke oven collecting pipe pressure control system.

[0006] A coke oven collecting pipe pressure control system, comprising:

[0007] No. 1 coke oven carbonization chamber 1 and No. 2 coke oven carbonization chamber 2, the No. 2 coke oven carbonization chamber 2 and the No. 1 coke oven carbonization chamber 1 are communicated with one end of collecting pipe 5 through pressure control pipe, the other end of the collecting pipe 5 is communicated with one end of gas-liquid separator 7; the pressure control pipe is used for controlling the gas inlet amount into the collecting pipe 5, so that the pressure of the collecting pipe is kept in a preset range; the other end of the gas-liquid separator 7 is communicated with the input end of primary cooler group, the output end of the primary cooler group is communicated with one end of fan 11 through pipeline 9, and fan front control butterfly valve 10 is arranged on the pipe wall of the pipeline 9, the other end of the fan 11 is provided with coal gas purification device 12.

[0008] Preferably, the pressure control pipe comprises: an ascending pipe 3, one end of the ascending pipe 3 is communicated with the first coke oven chamber 1, the other end of the ascending pipe 3 is communicated with one end of a bridge pipe 4, the other end of the bridge pipe 4 is communicated with the gas-liquid separator 7 through a suction pipe butterfly valve 6.

[0009] Preferably, the primary cooler group comprises four primary coolers 8 arranged uniformly; and the fan (11) is a variable frequency fan.

[0010] Preferably, the pipe 9 is selected from a φ500 pipe.

[0011] Preferably, the pressure of the first coke oven chamber 1 and the second coke oven chamber 2 at the end of coking is 5 Pa-20 Pa.

[0012] Preferably, the height of the first coke oven chamber 1 and the second coke oven chamber 2 from the ground is controlled to be 5.5 m, and the pressure of the gas collecting pipe 5 is 125 Pa-145 Pa.

[0013] The utility model also provides a coke oven gas collecting pipe pressure control method, comprising:

[0014] Step 1: high-temperature dry distillation is carried out to the coal in the first coke oven chamber 1 and the second coke oven chamber 2, the raw gas generated in the high-temperature dry distillation process is discharged through the ascending pipe 3 into the bridge pipe 4, and then enters the gas collecting pipe 5 after being cooled by ammonia water spraying in the inside of the bridge pipe 4;

[0015] Step 2: the treated raw gas enters the gas-liquid separator 7 from the gas collecting pipe 5, is centrifugally separated and is screened by a wire mesh, and after the filtration is finished, enters the inside of the primary cooler group to be cooled;

[0016] Step 3: after being cooled by the primary cooler 8, the raw gas enters the coal gas purification device 12 through the pipe 9, and is finally sent to a coal gas user.

[0017] Preferably, in step 1, the temperature of high-temperature dry distillation is controlled to be 900-1100 degrees Celsius.

[0018] According to the specific embodiment provided by the utility model, the utility model discloses the following technical effects:

[0019] Compared with the prior art, the utility model discloses a coke oven gas collecting pipe pressure control system, which comprises a fan front control butterfly valve arranged at the front end of the fan, and a suction pipe butterfly valve arranged in the gas collecting pipe of the first coke oven chamber and the second coke oven chamber, so as to control the gas inlet amount of the gas collecting pipe, keep the pressure of the gas collecting pipe in a preset range, and improve the stability of the system.

[0020] In order to make the above object, features and advantages of the present application more obvious, the following preferred embodiments are described in detail, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0022] Figure 1 The present application provides a schematic diagram of the coke oven gas collector pressure control system structure;

[0023] Figure 2 The gas collector pressure curve before frequency conversion is used;

[0024] Figure 3 The gas collector pressure curve after frequency conversion is used.

[0025] In the figure: 1, the first coke oven carbonization chamber, 2, the second coke oven carbonization chamber, 3, the riser pipe, 4, the bridge pipe, 5, the gas collector, 6, the gas suction pipe butterfly valve, 7, the gas-liquid separator, 8, the primary cooler, 9, the pipeline, 10, the fan front control butterfly valve, 11, the fan, 12, the coal gas purification device. DETAILED DESCRIPTION

[0026] In the description of the present application, it is understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0027] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0028] In the utility model, unless another definite provision and limitation, the terms "mount", "link", "connect", "fix" and so on terms should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connect;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can be indirectly connected through intermediate medium, can be the intercommunication of two elements inside.For the ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to specific circumstances.

[0029] Please refer to Figure 1 A coke oven gas collecting pipe pressure control system, comprising:

[0030] The coke oven carbonization chamber 1 and the coke oven carbonization chamber 2, the coke oven carbonization chamber 2 and the coke oven carbonization chamber 1 are communicated with one end of the gas collecting pipe 5 through the pressure control pipe, the other end of the gas collecting pipe 5 is communicated with one end of the gas-liquid separator 7;The pressure control pipe is used for controlling the gas inlet amount into the gas collecting pipe 5, so that the pressure of the gas collecting pipe is kept in the preset range;The other end of the gas-liquid separator 7 is communicated with the input end of the primary cooler group, the output end of the primary cooler group is communicated with one end of the fan 11 through the pipeline 9, and the pipeline 9 is provided with a fan front control butterfly valve 10 on the pipe wall, and the other end of the fan 11 is provided with a coal gas purification device 12.The primary cooler group includes four uniformly arranged primary coolers 8.

[0031] Further, the pressure control pipe comprises: an ascending pipe 3, one end of the ascending pipe 3 is communicated with the coke oven carbonization chamber 1, the other end of the ascending pipe 3 is communicated with one end of the bridge pipe 4, the other end of the bridge pipe 4 is communicated with the gas-liquid separator 7 through the gas suction pipe butterfly valve 6.

[0032] It should be noted that the model of the pipeline 9 is φ500 pipeline;The fan (11) is a variable frequency fan.The pressure of the coke oven carbonization chamber 1 and the coke oven carbonization chamber 2 at the end of coking is 5Pa-20Pa.The height of the coke oven carbonization chamber 1 and the coke oven carbonization chamber 2 from the ground is controlled to be 5.5m, and the pressure of the gas collecting pipe 5 is 125Pa-145Pa.

[0033] The utility model also provides a kind of coke oven gas collecting pipe pressure control method, applied to the coke oven gas collecting pipe pressure control system described above, comprising:

[0034] Step one: first, the coal in the coke oven carbonization chamber 1 and the coke oven carbonization chamber 2 is subjected to high-temperature dry distillation, and the temperature of high-temperature dry distillation is controlled at 900-1100 degrees Celsius, and the high-temperature dry distillation process generates high-temperature raw coal gas, which is discharged into the bridge pipe 4 through the ascending pipe 3, and is cooled after being sprayed with ammonia water in the bridge pipe 4, and then enters the gas collecting pipe 5;

[0035] Step two: from the gas collector 5 into the gas-liquid separator 7, by centrifugal separation and screen filtration, to achieve the treatment of liquid in the gas, and after the treatment, from the gas-liquid separator 7 into the inside of the primary cooler 8 to cool the gas;

[0036] Step three: after the cooling through the primary cooler 8, through the pipeline 9 into the coal gas purification device 12, the pipeline 9 is arranged between the primary cooler 8 and the coal gas purification device 12, and the fan 11 is arranged in the inside of the pipeline 9, and the fan front control butterfly valve 10 is arranged at the air inlet end of the fan 11, and finally sent to the gas user.

[0037] Comparison of the effects of the gas collector pressure control before and after the fan frequency conversion is put into use:

[0038] 1. The gas collector pressure before the fan frequency conversion is put into use: Before the fan frequency conversion is transformed, the coke oven gas collector pressure control uses one adjusting disc valve control, and the effect of controlling the gas collector pressure is as follows: Figure 2 It can be seen that the controlled gas collector pressure appears frequent oscillation wave, that is, it does not converge or expand, and no matter whether the coke oven is in the maintenance period or in the production of high-pressure ammonia water coal loading smoke elimination process, the gas collector pressure curve has no obvious difference, that is, its control state is a kind of balanced oscillation. But in the same parameter operation, this kind of balance often appears oscillation expansion, violent fluctuation, and the whole system operation is not very stable, which leads to serious smoke during the coke oven production.

[0039] 2. The gas collector pressure after the fan frequency conversion is put into use: After the fan frequency conversion is put into use, the gas collector pressure fluctuation curve becomes very regular as follows: Figure 3 This curve is the coke oven loading process, and then is a coke oven maintenance time. In the curve, the first peak appears at the beginning of the coke oven loading operation. Due to the requirement of environmental protection, the coal loading requires smoke elimination treatment, and this peak is the fluctuation of the gas collector pressure caused by the opening of the high-pressure ammonia water smoke elimination. The slight pressure fluctuation after the peak is the coal loading operation process, and then another trough appears, which is the operation of closing the high-pressure ammonia water smoke elimination after the coal loading is finished. Then it is a stable pressure curve, followed by the next coal loading process. The whole pressure fluctuation curve repeats periodically with the coal loading smoke elimination operation, and the system control is stable. During the coke oven maintenance, there is no high-pressure ammonia water smoke elimination operation, and the gas collector pressure curve is very stable and gentle.

[0040] 3. Effect comparison and analysis:

[0041] (1) Effect comparison:

[0042] The frequency control of the gas collecting pipe pressure, although in a coke oven charging operation cycle, a transient peak and trough, its amplitude can be basically equivalent to the reform before the oscillation amplitude, and because of the time at the peak is shorter, the coke oven does not produce smoke phenomenon. More importantly, when the frequency control, the system is more stable, the ability to adapt to production fluctuations is stronger. While the butterfly valve control system with the production fluctuations, its frequent adjustment effect will be worse, the oscillation will be enlarged, resulting in smoke phenomenon. Frequency control after the peak, trough phenomenon analysis. In the coke oven bridge pipe of the riser, by spraying high pressure ammonia water to produce a large suction, the large amount of smoke and dust generated during the charging process is sucked into the gas collecting pipe, replacing the original direct smoke and dust from the riser to the atmosphere. Operation, so as to achieve the purpose of reducing coke pollution and smoke. But the high pressure ammonia water charging smoke reduction has the disadvantage of causing the gas collecting pipe pressure to fluctuate sharply, and at the same time, the operation of the tar ammonia water separation tank is deteriorated. In the frequency conversion debugging, through the microcomputer display observation, when the high pressure ammonia water smoke elimination is opened, the gas collecting pipe pressure can rise to within one second, and its change is quite violent. In the process of parameter debugging of the frequency conversion of the fan, even the instantaneous high pressure burst of the riser cover appears. For energy saving considerations, when the frequency conversion is running, the fan running frequency takes the gas collecting pipe pressure as the control parameter, and in the running process, the control butterfly valve on the coke oven suction pipe maintains a larger opening and smaller pressure drop. In this way, the total resistance of the fan is reduced, and the energy saving efficiency is improved. When the high pressure ammonia water smoke elimination is opened, a large amount of smoke gas needs to be quickly improved to the conveying capacity of the pipeline, so as to ensure the stability of the gas collecting pipe pressure and the coke oven not to smoke and fire. The only two ways to improve the conveying capacity of the pipeline are to reduce the local pressure loss of the regulating valve, that is, to open the regulating valve opening, and to increase the fan running speed. Because of the frequency conversion operation, the basic opening of the regulating valve is large, according to the working characteristics of the butterfly valve, when the opening reaches a certain degree, its regulation ability will be poor, and the large opening degree will have serious hysteresis, which cannot meet the regulation effect. For high voltage frequency converter, in order to maintain its normal operation,

[0043] The frequency conversion device has certain limit in frequency increasing and decreasing rate, so it has certain regulation lag. In addition, the fan and the coke oven gas collecting pipe have certain pipe distance, so there is lag in pipe pressure transmission and in fan operation inertia, and the lag of fan frequency conversion regulation is increased. In this case, when the high pressure ammonia water is opened, the gas collecting pipe pressure fluctuates very sharply and has large amplitude, which is equivalent to a sharp rectangular interference wave, which cannot be completely eliminated by feedback regulation system. Therefore, the wave crest and wave trough phenomenon of the gas collecting pipe pressure cannot be avoided, and the parameter debugging work is how to keep the stability of the control system and reduce the amplitude of the wave crest and wave trough. Analysis of oscillation wave when the fan is operated at power frequency. When the fan is operated at power frequency, the full regulating valve butterfly valve is used to control the gas collecting pipe pressure. When the opening of the butterfly valve is less than 50%, the flow characteristic is approximately equal percentage flow characteristic, when the opening is small, the regulation is also relatively stable and moderate, and when the opening is large, it is also relatively sensitive. However, due to the large capacity of the fan in design, when the power frequency is started, in order to ensure that the regulating valve has certain opening, the valve before the fan is often opened very small to bear most of the pressure drop. Therefore, when the regulating valve is fully opened, the ratio of the pressure difference on the valve to the total pressure difference of the fluid system is reduced, so that the equal percentage flow characteristic of the butterfly valve becomes approximately linear flow characteristic or even fast opening flow characteristic, and when the opening is low,

[0044] The regulation is too strong, which is easy to produce oscillation, and the regulation is too weak at large opening, which is slow. Therefore, in order to suppress the wave crest and wave trough produced by high pressure ammonia water smoke elimination, low opening operation is often used. Due to the over sensitive regulation, the oscillation wave curve of the gas collecting pipe pressure when the fan is operated at power frequency is produced. When the production is adjusted, the change of gas quantity leads to the change of the basic opening of the regulating valve. If the opening of the valve before the fan is not adjusted accordingly, the regulating valve keeps the original basic opening, the regulating effect will become slow or over sensitive due to the increase or decrease of the opening of the regulating valve, so that the regulation effect is poor and the system oscillates.

[0045] Selection of fan frequency conversion control scheme:

[0046] Because the two coke ovens share one fan in the process, after the fan frequency conversion is reformed, three adjusting actuators are still needed, one is the fan frequency, and the other two are butterfly valves on the suction pipes of the two coke ovens, which are used to adjust the pressure balance of the two coke ovens. However, the relationship between the frequency conversion and the two butterfly valves should be fully considered in terms of the primary and secondary effects of adjustment and the adjustment accuracy of the adjusting device to achieve the ideal control state of the gas collector pressure. As described above, the actuator of the butterfly valve is a mechanical transmission control, and its control accuracy is closely related to the mechanical manufacturing. Moreover, its accuracy is inevitably affected by problems such as lubrication and wear during mechanical operation. In summary, during the debugging process, it can be observed that the action of the butterfly valve actuator has a certain step, and only a certain amount of adjustment can act, with a significant lag. When the adjustment amount is large, the lag of the adjustment is even more. Compared with the butterfly valve, the frequency conversion adjustment can be considered continuous, and it can achieve very accurate adjustment. Therefore, when selecting the control scheme, the control mode of parallel connection of the frequency conversion and the butterfly valve is adopted, with the frequency conversion control as the main control and the butterfly valve control as the auxiliary control. Even the control butterfly valve of one of the coke ovens is set to double to adjust the two coke ovens. The small pipeline connection is used for the collector pipe of the machine side of the two coke ovens to reduce the mutual effect of the adjusting devices in the system.

[0047] Problems that should be paid attention to during the debugging of the fan frequency conversion:

[0048] 1. The problem of pipeline pressure transmission lag:

[0049] As can be seen from the previous process flow, there is a certain pipeline distance from the fan to the coke oven collector pipe, and four high primary coolers are also passed through. Therefore, the entire pipeline has a certain pressure transmission air resistance and air capacity.

[0050] When the pressure of a certain point in the system changes, the pressure of another point in the system changes when the system has not reached a stable state, where t is the time when the pressure of another point changes from P to P, and T is the product of air resistance and air capacity.

[0051] This leads to an increase in suction before the fan when the fan speed increases, and the suction before the fan is in a transient state. Only after a certain time of pressure transmission can the effect of the increased suction before the fan be reflected on the collector pipe pressure to form a stable air flow, resulting in a pressure transmission lag. Although the lag time is very short, it is unrealistic to completely suppress the impact of the coal loading smoke on the collector pipe pressure. Due to the existence of this lag, special attention should be paid when selecting the parameters of the frequency conversion. Slightly increasing the adjustment effect may lead to system oscillation, and the wave peak produced when the high-pressure ammonia water is opened may be increased, and even the pressure may rise and open the pipe cover.

[0052] Therefore, in selection, the system oscillation and the gas collecting pipe pressure wave crest amplitude should be properly selected, and it is impossible to be all things to all men. In addition, when selecting the speed increasing and speed decreasing rate parameters of the high voltage frequency converter, it is not the faster the better. In the debugging process, if the parameter is set to be higher, the pressure does not necessarily improve significantly, and on the contrary, the oscillation is prone to occur.

[0053] PID parameter selection:

[0054] Due to the severe fluctuation of the gas collecting pipe pressure caused by the high pressure ammonia water smoke elimination, various parameter combinations are tried in the parameter debugging process, but the effect is not ideal, that is, the wave crest and wave trough amplitude caused by the high pressure ammonia water is too large, or the smooth pressure curve becomes jagged when the smoke elimination operation is not performed.

[0055] After observation and exploration, a parameter adjustment method is abandoned, and different parameters are used under different conditions of the gas collecting pipe pressure through logical judgment. Since the programming function of the industrial control software is very flexible, according to the pressure fluctuation curve, certain logical judgment parameters are set, so that the microcomputer can identify each process of the coke oven operation through the pressure change, and automatically adopt different parameters for control. Thus, the requirement of different control sensitivity of the gas collecting pipe pressure control in different operation stages of the coke oven is solved. Indeed, the high pressure ammonia water smoke elimination has a huge impact on the gas collecting pipe pressure, and when the final debugging is completed, the wave crest, the upper wave band, the lower wave band, the coal stage, the wave trough, the lower wave band, and the upper wave band of the gas collecting pipe pressure curve are set respectively. The logical judgment parameters and different parameters are set for the smoke elimination operation and the high pressure ammonia water, and a total of ten parameters are set on the three gas collecting pipe pressure control loops of the fan frequency conversion, the individual coke oven suction pipe regulating flap, and the like. In order to reduce the interaction of the three control loops, even one regulating flap is used for double position regulation.

[0056] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any skilled person in the art can easily think of changes or replacement technical solutions within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A coke oven header pressure control system characterized by, The utility model relates to a coke oven gas collecting and purifying device, including: No. 1 coke oven carbonization chamber (1) and no. 2 coke oven carbonization chamber (2), no. 2 coke oven carbonization chamber (2) and no. 1 coke oven carbonization chamber (1) are communicated with one end of gas collecting pipe (5) by pressure control pipe, and the other end of gas collecting pipe (5) is communicated with one end of gas-liquid separator (7);The pressure control pipe is used for controlling the gas intake amount into the gas collecting pipe (5), makes the pressure of gas collecting pipe keep in the preset range;The other end of gas-liquid separator (7) is communicated with the input end of primary cooler group, and the output end of primary cooler group is communicated with one end of fan (11) through pipeline (9), and fan front control butterfly valve (10) is arranged on the pipe wall of pipeline (9), and the other end of fan (11) is provided with coal gas purification device (12).

2. A coke oven header pressure control system according to claim 1, wherein, The pressure control pipe includes: the riser (3), one end of the riser (3) is communicated with no. 1 coke oven carbonization chamber (1), the other end of the riser (3) is communicated with one end of bridge pipe (4), and the other end of bridge pipe (4) is communicated with the gas-liquid separator (7) through the gas suction pipe butterfly valve (6).

3. A coke oven header pressure control system as claimed in claim 1, wherein, The primary cooler group includes four uniformly arranged primary coolers (8);The fan (11) is a variable frequency fan.

4. A coke oven header pressure control system as defined in claim 1, wherein, The model of pipeline (9) is selected as φ500 pipeline.

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