Method for correcting carbonization chamber pressure regulation control parameters based on volatile matter of mixed coal

Abstract

The application discloses a method for correcting pressure regulation control parameters of a carbonization chamber based on volatile matter of mixed coal and a single-carbonization-chamber pressure regulation system of a coke oven. The method corrects pressure regulation control parameters of each carbonization chamber when the volatile matter content of mixed coal used in current production is different from that of mixed coal used in design of the coke oven. When the pressure regulation control parameter is a pressure control value at a bridge pipe, the pressure control value at the bridge pipe is corrected by using the volatile matter parameter of mixed coal. When the pressure regulation control parameter is an opening control value of a flow area regulation device of raw coal gas, the opening control value is corrected by using the volatile matter parameter of mixed coal. After the method corrects the pressure regulation control parameters of the single-carbonization-chamber, the bottom pressure of each carbonization chamber is better controlled to be stable in a slightly positive pressure state in each coking time section, and environmental problems caused by leakage of raw coal gas to the inside and the outside, problems of burning loss of coke and damage of equipment caused by suction of air are reduced.

Description

Technical Field

[0001] This invention relates to the field of coking technology, specifically to a method for adjusting the pressure regulation and control parameters of the carbonization chamber based on the volatile matter content of blended coal. Background Technology

[0002] Chamber coking process is a process in which coal is dry distilled in the carbonization chamber of a coke oven in the absence of air. The coking process in the carbonization chamber is a layered coking process, which proceeds layer by layer from the high-temperature furnace walls on both sides toward the center of the carbonization chamber, undergoing drying and dehydration, softening, plastic state, semi-coke solidification, and condensation to form coke.

[0003] During the initial stages of coal charging and coking, a large amount of raw coal gas is generated, with the pressure of raw coal gas in the carbonization chamber reaching its highest point. This production state easily leads to leakage from the furnace door to the outside of the coke oven, causing smoke pollution. Furthermore, due to the pressure difference between the carbonization chamber (positive pressure) and the combustion chamber (negative pressure), raw coal gas can leak into the combustion system through the gaps in the furnace wall bricks and burn in the combustion chamber. This not only wastes chemical products but also increases the concentration of sulfur dioxide in the coke oven combustion flue gas and raises the subsequent flue gas desulfurization operating costs due to the large amount of hydrogen sulfide contained in the raw coal gas.

[0004] As the coking process progresses, the amount of raw coal gas produced gradually decreases. Towards the end of the coking process, the amount of raw coal gas produced is reduced to a very small amount, and the composition and density of the raw coal gas also change significantly. The H2 content in the raw coal gas increases sharply, causing a sharp drop in pressure inside the carbonization chamber. The pressure at the bottom of the carbonization chamber may change from positive to negative, making it easy for external air to be drawn into the carbonization chamber through the furnace door sealing surface and the furnace head sealing surface. When the raw coal gas inside the carbonization chamber encounters air, it will burn locally at the air leakage point, causing damage to the furnace door blades, sealing materials, and coke. This not only affects the life of the equipment but also increases the ash content of the coke and reduces production.

[0005] Traditional coking technology typically stabilizes the gas collecting pipe pressure to a certain value. The goal of setting this value is to maintain a slightly positive pressure of 5-10 Pa at the bottom of the carbonization chamber during the final stage of coking, preventing the intake of air at this stage. This inevitably leads to excessively high internal pressure in most carbonization chambers during other coking stages, thus failing to reduce the environmental problems caused by raw coal gas leakage.

[0006] To reduce internal and external leakage of raw coke oven gas, the industry has developed various forms of single-carbonization-chamber pressure regulation technology, which involves adjusting the pressure of each individual carbonization chamber of the coke oven. The principle behind this technology is to divide the entire coking time into several segments. For each of these segments, different pressure values ​​are set at the bridge pipe. The pressure at the bridge pipe is then measured using pressure gauges, and the pressure is adjusted based on the feedback from the bridge pipe to the gas collecting pipe, or the opening of the flapper, to control and stabilize the pressure at the bridge pipe within the set value for the corresponding coking time segment. This technology typically divides the coking time into 5 to 9 segments, with the set pressure value gradually increasing for each segment as the coking time changes.

[0007] The single-carbonization chamber pressure regulation technology is based on the following conditions: 1. As the coking time progresses, the amount of raw coal gas generated gradually decreases; 2. To regulate the pressure in the carbonization chamber, the coking time is divided into several segments, with different pressure values ​​set at the bridge pipe for each segment. These pressure values ​​increase segment by segment. During regulation, the pressure value at this point needs to be measured and fed back to control the pressure there. This is achieved by gradually reducing the channel area from the bridge pipe to the gas collecting pipe, i.e., gradually reducing the raw coal gas flow area. This single-carbonization chamber pressure regulation system using this control method can reduce the average pressure in the carbonization chamber throughout the entire coking time, thus reducing raw coal gas leakage.

[0008] However, in practical applications, whether it's setting the pressure value at the bridge pipe for each coking time segment or controlling the opening value of the regulating flap or other adjustable resistance devices, only the coking time of the coke oven is considered. The changes in the volatile matter content of the blended coal that cause variations in the amount of raw coal gas generated are not taken into account. This results in increased pressure fluctuations at the bottom of the single carbonization chamber of the coke oven when the blended coal ratio or coal type changes, leading to changes in the volatile matter content of the blended coal. When the volatile matter content of the blended coal decreases, it often causes a decrease in pressure or even negative pressure in the carbonization chamber, allowing air to easily leak into the carbonization chamber, causing coke burn-out or damage to the furnace door, furnace frame, and furnace body. When the volatile matter content of the blended coal increases, it often causes an increase in pressure in the carbonization chamber, resulting in smoke and fire, which is detrimental to further improving the environmental protection level of the coke oven. Summary of the Invention

[0009] To overcome the shortcomings of the above-mentioned technologies, this invention provides a method for correcting the pressure regulation and control parameters of the carbonization chamber based on the volatile matter of blended coal, thereby solving the problem that the pressure regulation and control parameters of a single carbonization chamber in a coke oven cannot adapt to changes in the volatile matter of the coking blended coal, resulting in large pressure fluctuations in the carbonization chamber.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] The method for correcting the pressure regulation control parameters of the carbonization chamber based on the volatile matter content of blended coal is as follows: when the volatile matter content of the blended coal currently used in production differs from that of the blended coal designed for the coke oven, the pressure regulation control parameters of each carbonization chamber are corrected: when the pressure regulation control parameter is the pressure control value at the bridge pipe, the pressure control value at the bridge pipe is corrected using the volatile matter content of the blended coal; when the pressure regulation control parameter is the opening control value of the raw coal gas flow area adjustment equipment, the opening control value is corrected using the volatile matter content of the blended coal.

[0012] Preferably, the method for correcting the pressure control value at the bridge pipe is as follows:

[0013] (1) When V≥V0:

[0014] P=P0×{1-[(V-V0)÷(100×V0)] 1 / 2};

[0015] (2) When V < V0:

[0016] P=P0×{1+[(V0-V)÷(100×V0)] 1 / 2};

[0017] Where: P is the pressure control value at the bridge pipe after correction based on the change in volatile matter content of the blended coal, in Pa; P0 is the original design pressure control value at the bridge pipe, in Pa; V is the volatile matter content of the blended coal currently used in production, in %; V0 is the volatile matter content of the blended coal designed for use in the coke oven, in %.

[0018] Preferably, the method for correcting the opening control value is as follows:

[0019] (1) When V≥V0:

[0020] K=K0×{1+[(V-V0)÷(100×V0)] 1 / 2};

[0021] (2) When V < V0:

[0022] K=K0×{1-[(V0-V)÷(100×V0)] 1 / 2};

[0023] Wherein, K is the opening control value of the raw coal gas flow area regulating equipment after correction based on the change in volatile matter content of the blended coal, in %; K0 is the original design opening control value of the raw coal gas flow area regulating equipment, in %; V is the volatile matter content of the blended coal currently used in production, in %; V0 is the volatile matter content of the blended coal designed for use in the coke oven, in %.

[0024] Preferably, the raw coal gas circulation area regulating device includes a flap valve, and the opening control value is the opening control value of the flap in the flap valve.

[0025] The present invention also provides a pressure regulation system for a single carbonization chamber of a coke oven, used to implement the above-mentioned method for correcting the pressure regulation control parameters of the carbonization chamber based on the volatile matter of blended coal, including a control module, wherein the control module controls the correction of the pressure regulation control parameters of each carbonization chamber.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention provides a method and system for adjusting the pressure control parameters of the carbonization chamber based on the volatile matter content of blended coal. When the blending ratio or type of blended coal used in a coke oven changes, the volatile matter content of the blended coal changes, and the amount of raw coal gas generated in each coking stage of each single carbonization chamber also changes accordingly. By correcting the pressure control values ​​at each stage of the bridge pipe or the opening values ​​of other raw coal gas flow area adjustment devices through the method of this invention, the pressure of a single carbonization chamber in the coke oven can be further precisely controlled. This better controls the bottom pressure of the carbonization chamber to remain stable in a slightly positive pressure state in each coking time segment, reducing the fluctuations in carbonization chamber pressure caused by changes in the volatile matter content of blended coal, and reducing the environmental problems caused by raw coal gas leakage to the inside or outside, or the problems of air intake burning coke and damaging equipment. Detailed Implementation

[0028] To better explain the present invention, the main contents of the present invention are further illustrated below in conjunction with specific embodiments, but the contents of the present invention are not limited to the following embodiments.

[0029] This invention provides a pressure regulation system for a single coke oven carbonization chamber, used to implement the method of correcting the carbonization chamber pressure regulation control parameters based on the volatile matter of blended coal, comprising a control module for controlling the correction of the carbonization chamber pressure regulation control parameters.

[0030] This invention provides a method for correcting the pressure regulation control parameters of the carbonization chamber based on the volatile matter content of blended coal. Based on single carbonization chamber pressure regulation technology, and considering the difference in volatile matter content between the blended coal currently used in production and the blended coal designed for the coke oven, the method corrects the pressure regulation control parameters for each carbonization chamber. When the pressure regulation control parameter is the pressure control value at the bridge pipe, the pressure control value at the bridge pipe is corrected using the volatile matter content parameter of the blended coal; when the pressure regulation control parameter is the opening control value of the raw coal gas flow area regulation equipment, the opening control value is corrected using the volatile matter content parameter of the blended coal. This method is mainly achieved by modifying the control program or setting a correction program in the control module of the single carbonization chamber pressure regulation system of the coke oven, modifying the control value according to the calculation method proposed in this invention, so that the control value changes with the volatile matter content of the blended coal.

[0031] Specifically, the method for modifying the carbonization chamber pressure regulation and control parameters based on the volatile matter of blended coal proposed in this invention mainly falls into the following two categories:

[0032] I. When the pressure at the bridge tube is used as the pressure regulation control parameter in the single coking chamber pressure regulation system of a coke oven, including cases where the pressure at the bridge tube is controlled in segments by coking time and cases where the pressure at the bridge tube is infinitely regulated, the calculation method for correcting the coking chamber pressure control value using the volatile matter parameter of the blended coal is as follows:

[0033] (1) When V≥V0:

[0034] P=P0×{1-[(V-V0)÷(100×V0)] 1 / 2};

[0035] (2) When V < V0:

[0036] P=P0×{1+[(V0-V)÷(100×V0)] 1 / 2};

[0037] Where: P is the pressure control value at the bridge pipe after correction based on the change in volatile matter content of the blended coal, in Pa; P0 is the original design pressure control value at the bridge pipe, in Pa; V is the volatile matter content of the blended coal currently used in production, in %; V0 is the volatile matter content of the blended coal designed for use in the coke oven, in %.

[0038] II. When the pressure regulation system of a single coking chamber in a coke oven uses a flap valve or other raw coal gas flow area regulation equipment with segmented or stepless regulation based on the coking time, the calculation method for the opening control value after correction based on the change in volatile matter in the blended coal is as follows:

[0039] (1) When V≥V0:

[0040] K=K0×{1+[(V-V0)÷(100×V0)] 1 / 2}

[0041] (2) When V < V0:

[0042] K=K0×{1-[(V0-V)÷(100×V0)] 1 / 2}

[0043] Where: K is the opening control value of the raw coal gas flow area regulating equipment after correction based on the change in volatile matter content of the blended coal, in %; K0 is the original design opening control value of the raw coal gas flow area regulating equipment, in %; V is the volatile matter content of the blended coal currently used in production, in %; V0 is the volatile matter content of the blended coal designed for use in the coke oven, in %.

[0044] The following describes the application of the method and system described in this embodiment to modify the pressure control parameters of a single carbonization chamber on a 6-meter coke oven in a coking plant. The coke oven is designed to have a coking time of 19 hours, the pressure at the bridge pipe is controlled in 6 stages, and the volatile matter V0 of the blended coal used in the coke oven is designed to be 25% on a dry basis. On a certain day, the volatile matter V of the blended coal used in production was 27.4% on a dry basis.

[0045] The pressure regulation system of the single coking chamber of the coke oven described above was used to realize the automatic correction of the control value of the system program. The calculation results of the pressure control parameter values ​​before and after the correction for each coking time period are shown in Table 1.

[0046] Table 1: Calculation results of pressure control parameter values ​​for each coking time period before and after correction

[0047]

[0048] Before the correction, the pressure fluctuation range at the bottom of each individual carbonization chamber was -20 to 80 Pa. With the corrected control values, the pressure at the bottom of each individual carbonization chamber can be stabilized at 5 to 35 Pa, significantly reducing environmental pollution caused by raw coal gas leakage.

[0049] In this specific embodiment, the volatile matter in coal is determined according to GB / T212-2008 "Industrial Analysis Methods for Coal".

[0050] All other unspecified parts belong to the prior art.

Claims

1. A method for adjusting the pressure regulation and control parameters of the carbonization chamber based on the volatile matter content of blended coal, characterized in that: When the volatile matter content of the blended coal used in current production differs from that of the blended coal used in the coke oven design, the pressure regulation control parameters of each carbonization chamber are corrected: when the pressure regulation control parameter is the pressure control value at the bridge pipe, the pressure control value at the bridge pipe is corrected using the volatile matter parameter of the blended coal. When the pressure regulation control parameter is the opening control value of the raw coal gas circulation area regulation equipment, the opening control value is corrected using the volatile matter parameter of the blended coal; The method for correcting the pressure control value at the bridge pipe is as follows: (1) When V≥V0: P=P0×{1-[(V-V0)÷(100×V0)] ½ }; (2) When V < V0: P=P0×{1+[(V0-V)÷(100×V0)] ½ }; Where: P is the pressure control value at the bridge pipe after correction based on the change in volatile matter content of the blended coal, in Pa; P0 is the original design pressure control value at the bridge pipe, in Pa; V is the volatile matter content of the blended coal currently used in production, in %; V0 is the volatile matter content of the blended coal designed for use in the coke oven, in % The method for correcting the opening control value is as follows: (1) When V≥V0: K=K0×{1+[(V-V0)÷(100×V0)] ½ }; (2) When V < V0: K=K0×{1-[(V0-V)÷(100×V0)] ½ }; Where K is the opening control value of the raw coal gas flow area regulating equipment after correction based on the change of volatile matter in blended coal, in units of %; K0 is the original design opening control value of the raw coal gas flow area regulating equipment, in units of %.

2. The method for adjusting and controlling the pressure of the carbonization chamber based on the volatile matter content of blended coal according to claim 1, characterized in that: The raw coal gas circulation area regulating device includes a flap valve, and the opening control value is the opening control value of the flap in the flap valve.

3. A pressure regulation system for a single coke oven carbonization chamber, used to implement the method for adjusting the pressure regulation control parameters of the carbonization chamber based on the volatile matter of blended coal as described in any one of claims 1-2, characterized in that: It includes a control module that controls the correction of pressure regulation control parameters for each carbonization chamber.

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