A regenerative combustion system and its control method for fluctuating VOCs exhaust gas sources

Abstract

This invention provides a regenerative thermal combustion system and its control method for fluctuating VOCs exhaust gas sources, including an inlet pipeline, a pretreatment system, a regenerative thermal combustion device, and a control system. The pretreatment system includes multiple pretreatment paths arranged in parallel, including a first pretreatment path, a second pretreatment path, and a third pretreatment path. The control system includes a gas detection module, which is installed at least at the inlet and outlet of the pretreatment system to detect the exhaust gas parameters entering the pretreatment system. Exhaust gas output from the inlet pipeline enters the pretreatment system. The control system acquires the exhaust gas parameters through the gas detection module and activates the corresponding pretreatment path according to the changes in exhaust gas parameters to treat the exhaust gas concentration to a target range. The gas is then introduced into the regenerative thermal combustion device, thus controlling the regenerative thermal combustion system. This invention achieves "peak shaving and valley filling" pretreatment for fluctuating VOCs exhaust gas sources, reducing system energy consumption while ensuring system safety.

Description

Technical Field

[0001] This invention belongs to the field of waste gas treatment technology, specifically relating to a regenerative combustion system and its control method for fluctuating VOCs waste gas sources. Background Technology

[0002] As the fine chemical industry faces increasing environmental and VOCs control pressures, many chemical companies are choosing to collect, aggregate, and centrally treat factory and production waste gases. Regenerative Thermal Oxidizers (RTOs) have been widely used as end-of-pipe control technologies in industries such as petrochemicals, fine chemicals, and automotive painting.

[0003] The production processes in key industries such as pharmaceuticals, chemicals, and petrochemicals are complex and often intermittent, resulting in significant fluctuations in VOCs exhaust gas volume and concentration. This greatly impacts the safe operation of RTO (Regenerative Thermal Oxidizer) equipment. When the concentration is too low, the heat generated during combustion in the RTO is minimal, requiring additional fuel or electricity and leading to higher operating costs. When the concentration exceeds 25% of the lower explosive limit of VOCs, the system cannot handle the excessively high concentration in time, posing a risk of combustion and explosion. Furthermore, the investment in waste gas incineration equipment is high, and companies typically do not equip themselves with multiple incineration units. The collected exhaust gases are diverse in type and composition, originate from multiple sources, and exhibit large concentration fluctuations. Existing single RTO equipment is insufficient to buffer and treat rapidly increasing VOC concentrations, posing a significant risk of combustion and explosion. This results in substantial safety hazards and high operating costs for RTO equipment.

[0004] Therefore, improving the safety and stability of RTO systems to address the issue of fluctuating exhaust gas concentrations is an urgent problem to be solved.

[0005] CN105879574A discloses a VOCs concentration load buffering and regulating device. The device is filled with adsorbent material, which buffers and regulates the VOCs concentration load by "peak shaving and valley smoothing" under normal temperature and pressure. Its drawbacks are that the fixed-design buffering and regulating device can handle a limited amount of waste gas, cannot precisely control the amount of gas adsorbed and desorbed, and does not limit the oversaturation of the adsorption capacity. Therefore, it is not suitable for long-term operation of fluctuating VOCs waste gas sources, and the treatment effect on fluctuating VOCs waste gas fails to meet expectations.

[0006] CN119123440A discloses a novel pretreatment process for high-concentration waste gas incineration in the hazardous waste industry, comprising the following steps: Step 1, waste gas enters a liquid-sealed system; Step 2, the liquid-sealed system treats the waste gas; Step 3, vacuum desorption; Step 4, waste gas recovery and liquid-sealing agent regeneration; Step 5, RTO system treatment. This invention uses a liquid-sealed system to treat waste gas according to its concentration, reducing the concentration of high-concentration waste gas and increasing the concentration of low-concentration waste gas. Its drawbacks include the inability to precisely control the dynamic adsorption and desorption of gas volume within the liquid-sealed system, the need for additional desorption within the liquid-sealed system, resulting in high operating costs and reduced treatment efficiency. Furthermore, its treatment effect on fluctuating VOCs waste gas does not meet expectations. Summary of the Invention

[0007] The purpose of this invention is to address the problem of large fluctuations in VOCs concentration in waste gas from key industries, which affects the safety and stability of RTO systems in existing technologies. Therefore, this invention provides a regenerative thermal combustion system and its control method for fluctuating VOCs waste gas sources.

[0008] To achieve the above objectives, the present invention proposes the following technical solution: A regenerative thermal combustion system for fluctuating VOCs exhaust gas sources includes an intake pipeline, a pretreatment system, a regenerative thermal combustion device, and a control system. The inlet end of the pretreatment system is connected to the outlet end of the intake pipeline, and the outlet end of the pretreatment system is connected to the inlet end of the regenerative thermal combustion device. The preprocessing system includes multiple preprocessing paths arranged in parallel, including a first preprocessing path, a second preprocessing path, and a third preprocessing path; The control system includes a gas detection module, which is at least located at the inlet and outlet of the pretreatment system and is used to detect the parameters of the exhaust gas entering the pretreatment system. The exhaust gas output from the intake pipe enters the pretreatment system. The control system obtains the exhaust gas parameters through the gas detection module and activates the corresponding pretreatment path according to the changes in the exhaust gas parameters to treat the exhaust gas concentration to the target range. Then, the exhaust gas is introduced into the regenerative combustion device to realize the control of the regenerative combustion system.

[0009] Specifically, the exhaust gas parameters detected by the gas detection module include, but are not limited to, exhaust gas volume, gas flow rate, exhaust gas concentration, and exhaust gas temperature.

[0010] Specifically, the target range for exhaust gas concentration is a range that can meet the self-heating requirements of the regenerative combustion device and ensure safety without the risk of explosion.

[0011] Furthermore, the first preprocessing path includes a first pipeline; The inlet end of the first pipeline is connected to the outlet end of the air intake pipeline, and the outlet end of the first pipeline is connected to the inlet end of the regenerative combustion device. The first pretreatment path can directly introduce the exhaust gas into the regenerative combustion device.

[0012] Furthermore, the second pretreatment path includes a second pipeline, a first pretreatment device, and a third pipeline; The inlet end of the second pipeline is connected to the outlet end of the air intake pipeline, the outlet end of the second pipeline is connected to the input end of the first pretreatment device, the inlet end of the third pipeline is connected to the output end of the first pretreatment device, and the outlet end of the third pipeline is connected to the inlet end of the regenerative combustion device. The second pretreatment path is used to adsorb or desorb the exhaust gas through the first pretreatment device, and then pass it into the regenerative combustion device.

[0013] Furthermore, the third pretreatment path includes a fourth pipeline, a second pretreatment device, and a fifth pipeline; The inlet end of the fourth pipeline is connected to the output end of the first pretreatment device, the outlet end of the fourth pipeline is connected to the input end of the second pretreatment device, the inlet end of the fifth pipeline is connected to the output end of the second pretreatment device, and the outlet end of the fifth pipeline is connected to the inlet end of the regenerative combustion device. The third pretreatment path is used to adsorb or desorb the exhaust gas that has passed through the first pretreatment device through the second pretreatment device, and then pass it into the regenerative combustion device.

[0014] Furthermore, the pretreatment system also includes a fourth pretreatment path, which includes a sixth pipeline, a heat exchange device, a seventh pipeline, and an eighth pipeline; The inlet end of the sixth pipeline is connected to the outlet end of the regenerative combustion device, the outlet end of the sixth pipeline is connected to the input end of the heat exchange device, the inlet end of the seventh pipeline is connected to the output end of the heat exchange device, the outlet end of the seventh pipeline is connected to the input end of the second pretreatment device, the inlet end of the eighth pipeline is connected to the output end of the second pretreatment device, and the outlet end of the eighth pipeline is connected to the inlet end of the regenerative combustion device. The fourth pretreatment path is used to draw hot gas flow from the regenerative combustion device to desorb the waste gas adsorbed by the second pretreatment device, and then pass it into the regenerative combustion device.

[0015] Specifically, the heat exchange device is externally connected to a circulating water cooling device or a circulating air cooling device.

[0016] The heat exchange device achieves heat exchange balance by controlling the flow rate of external air or water, thereby regulating the temperature of the hot airflow passing through the heat exchange device. External cold sources, after being heated by the heat exchange device, can be used for heating within the plant area.

[0017] The hot gas flow after passing through the heat exchange device enters the second pretreatment device in the fourth pretreatment path, where the VOCs gas adsorbed in the second pretreatment device is released slowly. The amount and temperature of the hot gas entering the second pretreatment device can be controlled by adjusting the gas flow rate from the sixth pipeline and the flow rate of the external cold source of the heat exchange device, thereby controlling the slow release rate and concentration of the gas adsorbed in the second pretreatment device.

[0018] Specifically, the equipment types of the first and second pretreatment devices can be selected based on factors such as the type of waste gas source, including but not limited to pretreatment adsorption towers and pretreatment adsorbers.

[0019] Pretreatment absorption towers include, but are not limited to, packed towers, and pretreatment adsorbers include, but are not limited to, fixed beds.

[0020] The absorbent in the absorption tower can be selected from water, white oil, glycerin, NMP, etc., depending on the type of waste gas source. An electric heater installed at the bottom of the absorption tower heats the absorbent, promoting the slow release of absorbed VOCs. The adsorbent in the adsorber can be selected from granular activated carbon, honeycomb activated carbon, zeolite honeycomb, hollow strip molecular sieve, macroporous resin, etc., depending on the type of waste gas source.

[0021] Preferably, the liquid-to-gas ratio of the pretreatment absorption tower during operation is <4 L / m³. 3 The empty tower gas velocity is <2 m / s, and the residence time is >2 s; the waste gas residence time during the operation of the pretreatment adsorber is 0.5-2s, and the gas flow rate is 0.1-1.2 m / s.

[0022] Specifically, by controlling the liquid-to-gas ratio and gas flow rate of the pretreatment device, the residence time of the waste gas in the absorption tower is ensured, guaranteeing the adsorption time of high-concentration waste gas and the slow release time of low-concentration waste gas, thus ensuring sufficient buffer time for regulating the waste gas concentration.

[0023] Furthermore, the first pretreatment device is equipped with a heating device.

[0024] Specifically, the control system regulates the amount of gas released from the pretreatment device by adjusting the heating temperature, thereby achieving precise control of the exhaust gas output concentration.

[0025] A control method for a regenerative combustion system for fluctuating VOCs exhaust gas sources includes the following steps: S1. Exhaust gas enters the pretreatment system from the inlet pipe, and the control system obtains the inlet gas concentration C2 and the outlet gas concentration C1 of the pretreatment system. S2, The control system controls the preprocessing system according to C2 and C1: When C S1 ≤C2<C S2Start the first preprocessing path, and then when C S1 ≤C1<C S2 Execute S3; When C S2 ≤C2<C S3 Enable the second preprocessing path, and then when C S1 ≤C1<C S2 Execute S3; When C S2 ≤C2<C S3 Enable the second and third preprocessing paths, and then when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 Enable the second preprocessing path, and then when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 Enable the second and third preprocessing paths, and then when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 The second preprocessing path is initiated, and the heating device of the first preprocessing unit is activated, thereby activating C. S1 ≤C1<C S2 Execute S3; When C2 < C S1 The second and fourth preprocessing paths are activated, and the heating device and heat exchange device of the first preprocessing unit are activated, thereby activating C. S1 ≤C1<C S2 Execute S3; S3. Exhaust gas enters the regenerative combustion device; Among them, C S1 <C S2 <C S3 ; The C S1 The first set value for exhaust gas concentration; the C S2 The second set value for exhaust gas concentration; the C S3 This is the third set value for exhaust gas concentration.

[0026] Furthermore, in step S2: When C S2 ≤C2<C S3 First, start the second preprocessing path, and then when C S2 ≤C1<C S3 Then start the third preprocessing path, and finally when C S1 ≤C1<C S2Execute S3; When C2 < C S1 First, start the second preprocessing path, and then when C1 < C S1 Then start the third preprocessing path, and finally when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 First, enable the second and third preprocessing paths, and then when C1 < C S1 Then close the third preprocessing path and turn on the heating device of the first preprocessing unit. Finally, when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 First, the second preprocessing path is started, and then the heating device of the first preprocessing unit is turned on. Then, when C1 < C... S1 Then start the fourth pretreatment path and the heat exchange device, and finally when C S1 ≤C1<C S2 Execute S3.

[0027] Furthermore, in step S2: When C1≥C S2 C S1 =Cmin,C S2 =1 / 8 LEL, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And 1 / 4 q < q t <3 / 4 q, C S1 =Cmin,C S2 =1 / 8 LEL, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And q t <1 / 4 q, C S1 =Cmin, 1.2 Cmin≤C S2 ≤2.0 Cmin, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And q t >3 / 4 q, 2.0 Cmin≤C S1 ≤5.0 Cmin, C S2 =1 / 8 LEL, C S3 =1 / 4LEL; Where Cmin is the minimum concentration required to maintain self-heating combustion in the regenerative combustion device, LEL is the minimum explosive limit of the exhaust gas, and q t This refers to the real-time VOCs adsorption capacity of the pretreatment system. ; Where t is the running time of the pretreatment system, Q1 is the air volume of the pretreatment system, Q2 is the air volume of the pretreatment system, and q is the saturated adsorption capacity of the pretreatment system, which is the experimental value for a specific pollutant system under the same working conditions in the laboratory.

[0028] Specifically, Cmin is set based on the composition, concentration ratio, and calorific value of the exhaust gas source, while LEL is the minimum concentration limit at which the exhaust gas can explode when exposed to an open flame in the air.

[0029] Specifically, in order to ensure that the real-time VOCs adsorption capacity in the first pretreatment device, the second pretreatment device, and the overall pretreatment system is maintained at a safe level of 1 / 4 q-3 / 4 q, q t The intake air concentration C1 of the regenerative combustion device is interlocked and controlled.

[0030] During the process of "peak shaving and valley filling" of the input exhaust gas in the pretreatment system, when the real-time VOCs adsorption capacity of the system is low, the second set value is reduced to increase the VOCs storage capacity of the system by reducing the VOCs slow release capacity of the pretreatment system; when the real-time VOCs adsorption capacity of the system is high and there is a risk of oversaturation, the first set value is increased to reduce the VOCs storage capacity of the system by increasing the VOCs slow release capacity of the pretreatment system. This ensures that the VOCs adsorption capacity in the pretreatment system is always maintained at a safe level, which not only meets the self-heating requirements of the regenerative combustion device, but also avoids the pretreatment device from becoming oversaturated, which would require overall circulation desorption or replacement of the pretreatment system.

[0031] Specifically, during the execution of the above control method, the control system detects and adjusts the VOCs storage in the pretreatment system to always maintain it between 1 / 4 and 3 / 4 of the system's saturated adsorption capacity, ensuring that the pretreatment system always maintains sufficient buffer margin to cope with sudden increases in the concentration of exhaust gas.

[0032] Furthermore, in step S2: The heating temperature of the heating device in the first pretreatment unit is T3, and ΔC1 = C. S1 -C1, the control system automatically adjusts T3 according to △C1: When △C1≤0, the heating device of the first pretreatment device is not turned on; 0<△C1≤500 mg / m 3 At that time, T3 = 40℃; 500 mg / m3 <△C1≤1000 mg / m 3 At that time, T3 = 60℃; 1000 mg / m 3 <△C1≤2000 mg / m 3 At that time, T3 = 80℃; The gas temperature after processing by the heat exchange device is T4, the gas concentration at the outlet of the second pretreatment path is C3, and ΔC2=C S1 -C3, the control system automatically adjusts T4 according to △C2: When △C2≤0, the heat exchange device is not turned on; 0<△C2≤500 mg / m 3 At that time, T4 = 40℃; 500 mg / m 3 <△C2≤1000 mg / m 3 At that time, T4 = 60℃; 1000 mg / m 3 <△C2≤2000 mg / m 3 At that time, T4 = 80℃; 2000 mg / m 3 <△C2≤3000 mg / m 3 At that time, T4 = 100℃; 3000 mg / m 3 <△C2≤4000 mg / m 3 At that time, T4 = 120℃.

[0033] Specifically, in step S2, when the second pretreatment path is activated, the value of T3 is dynamically adjusted according to the VOCs storage amount estimated by the system in the first pretreatment device; in step S2, when the second pretreatment path and the fourth pretreatment path are activated simultaneously, the values ​​of T3 and T4 are dynamically adjusted according to the VOCs storage amount estimated by the system in the first pretreatment device and the second pretreatment device, so as to ensure that the exhaust gas is enriched within the safe set value range while ensuring the dynamic stability of the amount of exhaust gas stored in the pretreatment system.

[0034] The specific mechanism of the above control method is as follows: When the intake air concentration reaches the first set value to maintain the self-heating combustion of the regenerative combustion device, the system automatically opens the first pretreatment path and directly introduces the regenerative combustion device for combustion. At this time, the self-heating combustion of the regenerative combustion device is realized, and no additional energy supply is required.

[0035] When the intake gas concentration reaches the second set value, the system automatically opens the second or third pretreatment path to store some of the exhaust gas in the pretreatment system. The high-concentration exhaust gas is adsorbed by the pretreatment system to ensure its safety and stability, and maintains the concentration within the range that maintains the self-heating combustion of the regenerative combustion device without causing explosion hazards, thus achieving "peak shaving" treatment of high-concentration exhaust gas.

[0036] When the intake gas concentration is lower than the first set value, the system automatically opens the second or third pretreatment path. The exhaust gas stored in the pretreatment system is slowly released through room temperature stripping or heating to enrich the exhaust gas source, ensuring that the exhaust gas concentration entering the regenerative combustion device can maintain its self-heating combustion. In order to save energy and further increase the amount of slowly released exhaust gas, the fourth pretreatment path can be opened. Hot gas flow is drawn from the regenerative combustion device into the heat exchange device. At the same time, the temperature of the exhaust gas entering the second pretreatment device is regulated by the heat exchange device, thereby regulating the speed and concentration of the slowly released gas in the second pretreatment device. This achieves enrichment of the exhaust gas entering the regenerative combustion system through the fourth pretreatment path, realizing the "valley filling" treatment of low-concentration exhaust gas.

[0037] The beneficial effects of this invention are: (1) The regenerative combustion system of the present invention adopts a multi-stage pretreatment system of absorption / adsorption or a combination thereof. Combined with the optimized first pretreatment path, second pretreatment path, third pretreatment path and fourth pretreatment path, it realizes the "peak shaving and valley filling" pretreatment for fluctuating VOCs exhaust gas sources, ensuring that the exhaust gas entering the regenerative combustion device is always maintained within the concentration range that meets the requirements of self-heating and safety, and reducing system energy consumption under the premise of ensuring system safety. The stable combustion conditions further improve the exhaust gas purification efficiency and also avoid the environmental risk problem caused by the emergency emission of exhaust gas source concentration higher than 1 / 4 of the explosion limit.

[0038] (2) The regenerative combustion system of the present invention achieves dynamic regulation of the amount of waste gas adsorbed in the pretreatment system through the coordinated action of the control system and the control method. While ensuring the safety and stability of the regenerative combustion system, it avoids the waste gas adsorption amount of the pretreatment device being oversaturated and then recycled. It realizes the simplified design of the regenerative combustion pretreatment system, saves treatment steps, shortens the working conditions, and is suitable for long-term uninterrupted operation of fluctuating VOCs waste gas sources, reducing the number of shutdowns for treatment or maintenance.

[0039] (3) The regenerative combustion system and its control method of the present invention solve the environmental and safety risks caused by large fluctuations in the concentration of waste gas in key industries such as pharmaceuticals, chemicals and petrochemicals, greatly improve the purification efficiency of RTO system, reduce system operating energy consumption, and are applicable to the treatment of extremely large volumes of waste gas.

[0040] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0041] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0042] The accompanying drawings are not drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures can be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings. The embodiments in the drawings do not constitute any limitation on the invention. Other drawings can be obtained by those skilled in the art based on the following figures without inventive effort: Figure 1 This is a schematic diagram of a regenerative combustion system for fluctuating VOCs exhaust gas sources provided by the present invention; Figure 2 This is a flowchart of the control method for a regenerative combustion system for fluctuating VOCs exhaust gas sources provided by the present invention.

[0043] Legend: 1. First valve; 2. Second valve; 3. Third valve; 4. Fourth valve; 5. Fifth valve; 6. Sixth valve; 7. Seventh valve; 8. Eighth valve. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art.

[0045] The terms "first," "second," and similar words used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the features, wholes, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or sets thereof. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0046] See attached document Figure 1 This embodiment provides a regenerative combustion system for fluctuating VOCs exhaust gas sources, specifically including: an intake pipe, a pretreatment system, a regenerative combustion device, and a control system arranged in sequence. Typically, the inlet end of the pretreatment system is connected to the outlet end of the intake pipe, and the outlet end of the pretreatment system is connected to the inlet end of the regenerative combustion device.

[0047] The intake pipe is connected to the exhaust gas source and is used to input the exhaust gas into the pretreatment system. A fan is installed on the intake pipe.

[0048] The preprocessing system includes multiple preprocessing paths configured in parallel, including a first preprocessing path, a second preprocessing path, and a third preprocessing path.

[0049] The control system includes a first gas detection module, a second gas detection module, a third gas detection module, a mass flow meter, and a circulating water cooling device. The first gas detection module is located at the outlet of the pretreatment system, and the second gas detection module is located at the inlet of the pretreatment system. These modules are used to detect the parameters of the exhaust gas entering the pretreatment system.

[0050] The regenerative combustion system is equipped with an exhaust pipe at the outlet end to discharge the safe gases after combustion.

[0051] The first pretreatment path includes a first pipeline; the inlet end of the first pipeline is connected to the outlet end of the air intake pipeline, and the outlet end of the first pipeline is connected to the inlet end of the regenerative combustion device.

[0052] The first valve 1 is installed on the first pipeline.

[0053] The first pretreatment path is used to directly introduce the exhaust gas into the regenerative combustion device.

[0054] The second pretreatment path includes a second pipeline, a first pretreatment device, and a third pipeline; the inlet end of the second pipeline is connected to the outlet end of the intake pipeline, the outlet end of the second pipeline is connected to the input end of the first pretreatment device, the inlet end of the third pipeline is connected to the output end of the first pretreatment device, and the outlet end of the third pipeline is connected to the inlet end of the regenerative combustion device.

[0055] A second valve 2 is installed on the second pipeline, and a third valve 3 is installed on the third pipeline. A third gas detection module is installed at the front end of the third pipeline to detect the gas output parameters of the second pretreatment path.

[0056] The second pretreatment path is used to adsorb or desorb the exhaust gas through the first pretreatment device, and then pass it into the regenerative combustion device.

[0057] The third pretreatment path includes a fourth pipeline, a second pretreatment device, and a fifth pipeline. The inlet end of the fourth pipeline is connected to the output end of the first pretreatment device, the outlet end of the fourth pipeline is connected to the input end of the second pretreatment device, the inlet end of the fifth pipeline is connected to the output end of the second pretreatment device, and the outlet end of the fifth pipeline is connected to the inlet end of the regenerative combustion device.

[0058] A fourth valve 4 is installed on the fourth pipeline, and a fifth valve 5 is installed on the fifth pipeline.

[0059] To save on material costs and simplify pipeline design, the inlet of the fourth pipeline is connected to the middle of the third pipeline, specifically between the third gas detection module and the third valve 3.

[0060] The third pretreatment path is used to adsorb or desorb the exhaust gas that has passed through the first pretreatment device through the second pretreatment device, and then pass it into the regenerative combustion device.

[0061] The pretreatment system also includes a fourth pretreatment path, which includes a sixth pipeline, a heat exchange device, a seventh pipeline, and an eighth pipeline. The inlet end of the sixth pipeline is connected to the outlet end of the regenerative combustion device, and the outlet end of the sixth pipeline is connected to the input end of the heat exchange device. The inlet end of the seventh pipeline is connected to the output end of the heat exchange device, and the outlet end of the seventh pipeline is connected to the input end of the second pretreatment device. The inlet end of the eighth pipeline is connected to the output end of the second pretreatment device, and the outlet end of the eighth pipeline is connected to the inlet end of the regenerative combustion device.

[0062] A sixth valve 6 is installed on the sixth pipeline to draw out the safe hot gas flow after combustion from the heat storage combustion device. A mass flow controller is installed at the sixth valve 6 to control the opening degree of the sixth valve 6 and accurately control the amount of gas entering the heat exchange device.

[0063] A seventh valve 7 is installed on the seventh pipeline, and an eighth valve 8 is installed on the eighth pipeline.

[0064] The heat exchange device is connected to a circulating water cooling device. The efficiency of the heat exchange device is adjusted by adjusting the flow rate of the circulating water cooling device. The control system achieves precise control of the temperature and volume of the exhaust gas passing through the heat exchange device by adjusting the flow rate of the circulating water cooling device and the opening of the sixth valve 6.

[0065] The temperature range of the hot gas flow after being processed by the heat exchanger is 40-120℃. The lower the gas concentration at the outlet of the pretreatment system, the higher the temperature of the hot gas flow processed by the heat exchanger.

[0066] The fourth pretreatment path is used to draw hot gas from the regenerative combustion device to desorb the waste gas adsorbed by the second pretreatment device, and then pass it into the regenerative combustion device.

[0067] The aforementioned first gas detection module, second gas detection module, and third gas detection module are used to detect parameters of the passing gas in real time, including but not limited to concentration, temperature, and gas volume. Commercially available gas detectors or sensors can be used, including but not limited to photoionization detectors (PID), portable flame ionization detectors (FID), and lower limit combustible gas detectors (LEL).

[0068] The first pretreatment device mentioned above is a packed tower type pretreatment absorption tower, and the liquid-to-gas ratio during operation of the pretreatment absorption tower is <4 L / m³. 3 The empty tower gas velocity is <2 m / s, and the residence time is >2 s. Depending on actual needs, two or more pretreatment absorption towers can be installed in series or in parallel at the location of the first pretreatment unit.

[0069] An electric heater is installed at the bottom of the pretreatment absorption tower. The control system controls its on / off state and heating temperature. The heating temperature of the electric heater in the pretreatment absorption tower is 40-80℃. The lower the gas concentration of the pretreatment system, the higher the heating temperature of the electric heater.

[0070] The aforementioned second pretreatment device is a fixed-bed type pretreatment adsorber. During operation, the exhaust gas residence time is 0.5-2 seconds, and the gas flow rate is 0.1-1.2 m / s. Depending on actual needs, two or more pretreatment adsors can be installed in series or parallel at the location of the second pretreatment device.

[0071] By controlling the gas flow rate and residence time within the pretreatment device, sufficient buffer time is provided for the pretreatment system to process waste gas, facilitating timely adjustments to address situations with large fluctuations in waste gas concentration.

[0072] In summary, the exhaust gas enters the pretreatment system through the intake pipe. The control system acquires the exhaust gas parameters through the gas detection module and activates the corresponding pretreatment path according to the changes in the exhaust gas parameters. The exhaust gas adsorption and desorption of the pretreatment system are controlled by the electric heater, mass flow meter and circulating water cooling device to treat the exhaust gas concentration to the target range. Then it is introduced into the regenerative combustion device to realize the control of the regenerative combustion system.

[0073] The target range value is usually set within the concentration range that meets the self-heating and safety requirements of the regenerative combustion device, and is free from explosion risks. The above concentration range is set as the initial safe range. The target range value can be dynamically adjusted according to the real-time VOCs adsorption capacity of the pretreatment system to ensure that the concentration of exhaust gas entering the regenerative combustion device is always kept within the initial safe range. At the same time, the pretreatment system has no risk of oversaturation and does not require replacement or shutdown for maintenance.

[0074] See attached document Figure 2 This embodiment also provides a control method for a regenerative combustion system for fluctuating VOCs exhaust gas sources, specifically including a safety mode, a peak shaving mode, and a valley filling mode. The peak shaving mode and valley filling mode use a multi-stage pretreatment mode to dynamically regulate the concentration of unstable exhaust gas sources.

[0075] Safe Mode: Mode 1: When the exhaust gas concentration is within the range required to maintain self-heating combustion and ensure safety, the first pretreatment path is adopted. When the fan is turned on, the exhaust gas enters the pretreatment system through the intake pipe. When the second gas detection module detects that the exhaust gas concentration reaches the first set value and is lower than the second set value, the first valve 1 is opened and the exhaust gas enters the regenerative combustion device through the first pretreatment path.

[0076] Peak Shaving Mode: Mode 2: High exhaust gas concentration, using the second pretreatment path. When the fan is turned on, the exhaust gas enters the pretreatment system through the intake pipe. When the second gas detection module detects that the exhaust gas concentration reaches the second set value and is lower than the third set value, the first-level pretreatment mode is activated, and the second valve 2 and the third valve 3 are opened at the same time, and part of the exhaust gas is stored in the first pretreatment device.

[0077] When the third gas detection module or the first gas detection module detects that the exhaust gas concentration reaches the first set value and is lower than the second set value, the remaining exhaust gas enters the regenerative combustion device through the second pretreatment path.

[0078] Mode 3: Extremely high exhaust gas concentration, employing a third pretreatment path. When the fan is turned on, the exhaust gas enters the pretreatment system through the intake pipe. When the second gas detection module detects that the exhaust gas concentration reaches the second set value and is lower than the third set value, the first-level pretreatment mode is activated, and the second valve 2 and the third valve 3 are opened at the same time, and part of the exhaust gas is stored in the first pretreatment device.

[0079] If the third gas detection module or the first gas detection module detects that the exhaust gas concentration still reaches the second set value, the second-level pretreatment mode will be activated.

[0080] The third valve 3 is closed, while the fourth valve 4 and the fifth valve 5 are opened, and part of the waste gas is stored in the first pretreatment device and the second pretreatment device.

[0081] When the first gas detection module detects that the exhaust gas concentration reaches the first set value and is lower than the second set value, the remaining exhaust gas enters the regenerative combustion device through the third pretreatment path.

[0082] Valley filling mode: Mode 4: Low exhaust gas concentration, employing the second pretreatment path, primary pretreatment mode. When the fan is turned on, the exhaust gas enters the pretreatment system through the intake pipe. When the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first-level pretreatment mode is activated, and the second valve 2 and the third valve 3 are opened to release the exhaust gas stored in the first pretreatment device through room temperature stripping.

[0083] When the third gas detection module or the first gas detection module detects that the exhaust gas concentration reaches the first set value and is lower than the second set value, the exhaust gas enters the regenerative combustion device through the second pretreatment path.

[0084] Mode 5: Extremely low exhaust gas concentration, employing a third pretreatment path, a two-stage pretreatment mode. When the fan is turned on, the exhaust gas enters the pretreatment system through the intake pipe. When the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first-level pretreatment mode is activated, and the second valve 2 and the third valve 3 are opened to release the exhaust gas stored in the first pretreatment device through room temperature stripping.

[0085] If the third gas detection module or the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the second-level pretreatment mode will be activated.

[0086] Close the third valve 3, and simultaneously open the fourth valve 4 and the fifth valve 5 to slowly release the waste gas stored in the first pretreatment device and the second pretreatment device through room temperature stripping.

[0087] When the first gas detection module detects that the exhaust gas concentration reaches the first set value and is lower than the second set value, the exhaust gas enters the regenerative combustion device through the third pretreatment path.

[0088] Mode 6: Extremely low exhaust gas concentration, employing the second pretreatment path, a three-stage pretreatment mode. When the fan is turned on, the exhaust gas enters the pretreatment system through the intake pipe. When the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first-level pretreatment mode is activated, and the second valve 2 and the third valve 3 are opened to release the exhaust gas stored in the first pretreatment device through room temperature stripping.

[0089] If the third gas detection module or the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the second-level pretreatment mode will be activated.

[0090] Close the third valve 3, and simultaneously open the fourth valve 4 and the fifth valve 5 to slowly release the waste gas stored in the first pretreatment device and the second pretreatment device through room temperature stripping.

[0091] When the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the three-level pretreatment mode is activated.

[0092] Close the fourth valve 4 and the fifth valve 5, open the third valve 3, and turn on the heating device of the first pretreatment device to slowly release the waste gas stored in the first pretreatment device by heating. Adjust the concentration of the slowly released gas by regulating the heating temperature.

[0093] When the third gas detection module or the first gas detection module detects that the exhaust gas concentration reaches the first set value and is lower than the second set value, the exhaust gas enters the regenerative combustion device through the second pretreatment path.

[0094] Mode 7: Extremely low exhaust gas concentration, employing both the second and fourth pretreatment paths, a four-stage pretreatment mode. When the fan is turned on, the exhaust gas enters the pretreatment system through the intake pipe. When the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first-level pretreatment mode is activated, and the second valve 2 and the third valve 3 are opened to release the exhaust gas stored in the first pretreatment device through room temperature stripping.

[0095] When the third gas detection module or the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the secondary pretreatment mode is activated.

[0096] Close the third valve 3, and simultaneously open the fourth valve 4 and the fifth valve 5 to slowly release the waste gas stored in the first pretreatment device and the second pretreatment device through room temperature stripping.

[0097] When the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the three-level pretreatment mode is activated.

[0098] Close the fourth valve 4 and the fifth valve 5, open the third valve 3, and turn on the heating device of the first pretreatment device to slowly release the waste gas stored in the first pretreatment device by heating. Adjust the concentration of the slowly released gas by regulating the heating temperature.

[0099] When the third gas detection module or the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the fourth-level pretreatment mode is activated.

[0100] Simultaneously, valves 6, 7, and 8 are opened to draw hot gas from the regenerative combustion device. After being cooled by the heat exchange device, the hot gas enters the second pretreatment device for slow release of waste gas. By adjusting the gas volume released by valve 6 and the cold source flow of the heat exchange device, the temperature and flow rate of the hot gas entering the second pretreatment device are precisely controlled, thereby regulating the concentration of the slow-release gas in the second pretreatment device.

[0101] When the first gas detection module detects that the exhaust gas concentration reaches the first set value and is lower than the second set value, the exhaust gas enters the regenerative combustion device through the second pretreatment path and the fourth pretreatment path.

[0102] In this system, the inlet gas concentration and flow rate are C2 and Q2, and the outlet gas concentration and flow rate are C1 and Q1, respectively. Specifically, the first gas detection module detects the gas concentration and flow rate as C1 and Q1, the second gas detection module detects the gas concentration and flow rate as C2 and Q2, and the third gas detection module detects the gas concentration and flow rate as C3 and Q3. The heating temperature of the electric heater in the first pretreatment device is T3, which is specifically detected by the third gas detection module. The temperature of the gas after treatment by the heat exchange device is T4. The sixth valve 6 controls the flow rate as Q4. The system controls 1 / 20 Q2≤Q4≤1 / 5 Q2.

[0103] When the second preprocessing path is enabled alone, the data detected by the first gas detection module and the third gas detection module are the same.

[0104] During the execution of the above method, the first set value, the second set value, and the third set value are adjusted according to the real-time VOCs adsorption capacity q of the pretreatment system. t The changes allow for control over the amount of VOCs adsorbed in the pretreatment system, preventing it from being too low to enable the valley filling mode and also preventing it from being too high to oversaturate the pretreatment unit and prevent it from continuing to adsorb gases.

[0105] The real-time VOCs storage capacity of the pretreatment system is: ;

[0106] Where t is the running time of the pretreatment system, Q1 is the exhaust gas volume detected by the first gas detection module, Q2 is the exhaust gas volume detected by the second gas detection module, and q is the saturated adsorption capacity of the pretreatment system, which is the experimental value for a specific pollutant system under the same laboratory conditions.

[0107] During the execution of the above method, the VOCs storage capacity of the pretreatment system should be kept as low as possible, maintaining 1 / 4 q < q. t <3 / 4q, which allows the pretreatment system to perform "peak shaving and valley filling" pretreatment on unstable waste gas sources while leaving more buffer margin, ensuring that the VOCs storage of the pretreatment device in the pretreatment system is within a safe range, and ensuring that the pretreatment device will not become oversaturated with adsorbed gas.

[0108] If excessive fluctuations in gas concentration or other circumstances cause the VOCs storage capacity of the pretreatment system to exceed the safe range of 1 / 4 q to 3 / 4 q, the gas adsorption and release capacity of the pretreatment system will be adjusted in real time by adjusting the first and second setpoints to ensure that they return to the safe range as soon as possible. The specific adjustment method is as follows: When C1≥C S2 C S1 =Cmin,C S2 =1 / 8 LEL, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And 1 / 4 q < q t <3 / 4 q, C S1 =Cmin,C S2 =1 / 8 LEL, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And q t <1 / 4 q, C S1 =Cmin, 1.2 Cmin≤C S2 ≤2.0 Cmin, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And q t >3 / 4 q, 2.0 Cmin≤C S1 ≤5.0 Cmin, C S2 =1 / 8 LEL, C S3 =1 / 4LEL; Cmin is the minimum concentration required to maintain self-heating combustion in the RTO regenerative combustion device. The specific value is set according to the composition, concentration ratio, and calorific value of the exhaust gas source. LEL is the minimum explosion limit of the exhaust gas, which is the minimum concentration limit at which the exhaust gas will explode when it encounters an open flame in the air.

[0109] During the execution of the above method, when the gas is released slowly using the first pretreatment mode, the heating temperature of the electric heater of the first pretreatment device changes with the gas concentration detected by the first gas detection module, that is, the inlet gas concentration of the regenerative combustion device and the VOCs adsorption amount of the pretreatment system. This ensures that the gas released slowly by heating is kept at a level that can sustain the self-heating combustion of the regenerative combustion device and does not exceed the safety limit. At the same time, it ensures that the amount of waste gas adsorbed in the first pretreatment device in real time is kept within an appropriate range to avoid the occurrence of too little or too saturated gas.

[0110] The third gas detection module detected an exhaust gas temperature of T3, which is the heating temperature of the heating device in the first pretreatment unit. ΔC1 = C S1 -C1, the system automatically adjusts T3 based on △C1: When △C1≤0, the heating device of the first pretreatment unit is not turned on; 0<△C1≤500 mg / m 3 At that time, T3 = 40℃; 500 mg / m 3 <△C1≤1000 mg / m 3 At that time, T3 = 60℃; 1000 mg / m 3 <△C1≤2000 mg / m 3 At that time, T3 = 80℃; During the execution of the above method, when the hot gas flow after combustion is drawn from the regenerative combustion device to slowly release the waste gas into the second pretreatment device, the flow rate and temperature of the hot gas entering the second pretreatment device are jointly controlled by the opening of the sixth valve 6 and the flow rate of the cold source of the heat exchange device. This precisely controls the temperature of the hot gas entering the second pretreatment device after being processed by the heat exchange device, thereby controlling the concentration of the waste gas slowly released by the second pretreatment device. This control method is an existing mature technology and will not be described in detail here.

[0111] The concentration of the slow-release gas in the second pretreatment device is linked to the concentration of the slow-release gas in the first pretreatment device. When the concentration of the slow-release gas in the first pretreatment device is insufficient, the system controls the slow-release temperature of the second pretreatment device to increase, thereby releasing more gas for valley filling operation.

[0112] The gas temperature after processing by the heat exchanger is T4, which is the gas temperature entering the second pretreatment unit via the RTO reheat path. Alternatively, a gas temperature detection device can be installed at the seventh valve 7 to detect T4, where ΔC2 = C.S1 -C3, the system automatically adjusts T4 based on △C2: When △C2≤0, the heat exchange device is not turned on; 0<△C2≤500 mg / m 3 At that time, T4 = 40℃; 500 mg / m 3 <△C2≤1000 mg / m 3 At that time, T4 = 60℃; 1000 mg / m 3 <△C2≤2000 mg / m 3 At that time, T4 = 80℃; 2000 mg / m 3 <△C2≤3000 mg / m 3 At that time, T4 = 100℃; 3000 mg / m 3 <△C2≤4000 mg / m 3 At that time, T4 = 120℃.

[0113] Example 1 A regenerative thermal combustion system for fluctuating VOCs exhaust gas sources, the device used is shown in the attached figure. Figure 1 As shown.

[0114] The adsorbent in the first pretreatment device is water, with a reversible adsorption-desorption dynamic adsorption capacity of 35 mg / g and a liquid-to-gas ratio of 3 L / m³ during operation. 3 The empty tower gas velocity is 1.5 m / s, the residence time is 2.5 s, the adsorption material in the second pretreatment device is honeycomb activated carbon, its reversible adsorption and desorption dynamic adsorption capacity is 160 mg / g, the exhaust gas residence time is 1 s, and the gas flow rate is 1 m / s.

[0115] The regenerative combustion device is a three-chamber RTO.

[0116] The first, second, and third gas detection modules are model FID and mass flow controllers, which can detect gas concentration and flow rate.

[0117] The mass flow controller model is a thermal gas mass flow controller.

[0118] The heat exchange device is a plate heat exchanger.

[0119] The regenerative combustion system is in accordance with the appendix Figure 2 The control method shown operates at normal temperature and pressure, with VOCs concentration in the exhaust gas source ranging from 500 to 12000 mg / m³. 3The concentration of the exhaust gas fluctuates within a certain range, and after pretreatment, the concentration is 3000-6000 mg / m³. 3 The entire system has been running stably for more than a week without any abnormalities, and the exhaust gas from the regenerative combustion device meets environmental protection requirements.

[0120] Example 2 A regenerative thermal combustion system for fluctuating VOCs exhaust gas sources, the device used is shown in the attached figure. Figure 1 As shown.

[0121] The adsorbent in the first pretreatment device is water, with a reversible adsorption-desorption dynamic adsorption capacity of 35 mg / g and a liquid-to-gas ratio of 3 L / m³ during operation. 3 The empty tower gas velocity is 1.5 m / s, the residence time is 2.5 s, the adsorption material in the second pretreatment device is granular activated carbon, its dynamic adsorption capacity for reversible adsorption and desorption is 278 mg / g, the waste gas residence time during operation is 1 s, and the gas flow rate is 0.5 m / s.

[0122] The regenerative combustion device is a three-chamber RTO.

[0123] The first, second, and third gas detection modules are FID and mass flow controllers, which can detect gas concentration and flow rate.

[0124] The mass flow controller model is a thermal gas mass flow controller.

[0125] The heat exchange device is a shell-and-tube heat exchanger.

[0126] The regenerative combustion system is in accordance with the appendix Figure 2 The control method shown operates at normal temperature and pressure, with VOCs concentration in the exhaust gas source ranging from 100 to 50,000 mg / m³. 3 The concentration of the exhaust gas fluctuates within a certain range, and after pretreatment, the concentration is 3000-6000 mg / m³. 3 The entire system has been running stably for more than a week without any abnormalities, and the exhaust gas from the regenerative combustion device meets environmental protection requirements.

[0127] Example 3 A regenerative thermal combustion system for fluctuating VOCs exhaust gas sources, the device used is shown in the attached figure. Figure 1 As shown.

[0128] The adsorbent in the first pretreatment device is water, with a reversible adsorption-desorption dynamic adsorption capacity of 35 mg / g and a liquid-to-gas ratio of 3 L / m³ during operation. 3The empty tower gas velocity is 1.5 m / s, the residence time is 2.5 s, the adsorption material in the second pretreatment device is activated carbon fiber, its reversible adsorption and desorption dynamic adsorption capacity is 357 mg / g, the exhaust gas residence time during operation is 2 s, and the gas flow rate is 1 m / s.

[0129] The regenerative combustion device is a three-chamber RTO.

[0130] The first, second, and third gas detection modules are FID and mass flow controllers, which can detect gas concentration and flow rate.

[0131] The mass flow controller model is a thermal gas mass flow controller.

[0132] The heat exchange device is a plate heat exchanger.

[0133] The regenerative combustion system is in accordance with the appendix Figure 2 The control method shown operates at normal temperature and pressure, with VOCs concentration in the exhaust gas source ranging from 50 to 100,000 mg / m³. 3 The concentration of the exhaust gas fluctuates within a certain range, and after pretreatment, the concentration is 3000~6000 mg / m³. 3 The entire system has been running stably for more than a week without any abnormalities, and the exhaust gas from the regenerative combustion device meets environmental protection requirements.

[0134] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

[0135] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. Technical details not described in detail in this invention can all be implemented using any existing technology in the art. In particular, all technical features not described in detail in this invention can be implemented using any existing technology.

Claims

1. A regenerative combustion system for fluctuating VOCs exhaust gas sources, characterized in that, The regenerative combustion system includes an intake pipe, a pretreatment system, a regenerative combustion device, and a control system. The inlet end of the pretreatment system is connected to the outlet end of the intake pipe, and the outlet end of the pretreatment system is connected to the inlet end of the regenerative combustion device. The preprocessing system includes multiple preprocessing paths arranged in parallel, including a first preprocessing path, a second preprocessing path, and a third preprocessing path; The first pretreatment path connects the air intake pipe and the regenerative combustion device, and is used to directly introduce the exhaust gas into the regenerative combustion device. The second pretreatment path includes a first pretreatment device for adsorbing or desorbing the exhaust gas through the first pretreatment device, and then passing it into the regenerative combustion device. The third pretreatment path includes a second pretreatment device, which is used to adsorb or desorb the exhaust gas that has passed through the first pretreatment device and then pass it into the regenerative combustion device. The control system includes a gas detection module, which is at least located at the inlet and outlet of the pretreatment system and is used to detect the parameters of the exhaust gas entering the pretreatment system. The exhaust gas output from the intake pipe enters the pretreatment system. The control system obtains the exhaust gas parameters through the gas detection module and activates the corresponding pretreatment path according to the changes in the exhaust gas parameters to treat the exhaust gas concentration to the target range. Then, the exhaust gas is introduced into the regenerative combustion device to realize the control of the regenerative combustion system.

2. The regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 1, characterized in that, The first preprocessing path includes a first pipeline; The inlet end of the first pipeline is connected to the outlet end of the air intake pipeline, and the outlet end of the first pipeline is connected to the inlet end of the regenerative combustion device.

3. The regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 1, characterized in that, The second pretreatment path includes a second pipeline, a first pretreatment device, and a third pipeline; The inlet end of the second pipeline is connected to the outlet end of the air intake pipeline, the outlet end of the second pipeline is connected to the input end of the first pretreatment device, the inlet end of the third pipeline is connected to the output end of the first pretreatment device, and the outlet end of the third pipeline is connected to the inlet end of the regenerative combustion device.

4. A regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 3, characterized in that, The third pretreatment path includes a fourth pipeline, a second pretreatment device, and a fifth pipeline; The inlet end of the fourth pipeline is connected to the output end of the first pretreatment device, the outlet end of the fourth pipeline is connected to the input end of the second pretreatment device, the inlet end of the fifth pipeline is connected to the output end of the second pretreatment device, and the outlet end of the fifth pipeline is connected to the inlet end of the regenerative combustion device.

5. A regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 4, characterized in that, The pretreatment system also includes a fourth pretreatment path, which includes a sixth pipeline, a heat exchange device, a seventh pipeline, and an eighth pipeline. The inlet end of the sixth pipeline is connected to the outlet end of the regenerative combustion device, the outlet end of the sixth pipeline is connected to the input end of the heat exchange device, the inlet end of the seventh pipeline is connected to the output end of the heat exchange device, the outlet end of the seventh pipeline is connected to the input end of the second pretreatment device, the inlet end of the eighth pipeline is connected to the output end of the second pretreatment device, and the outlet end of the eighth pipeline is connected to the inlet end of the regenerative combustion device. The fourth pretreatment path is used to draw hot gas flow from the regenerative combustion device to desorb the waste gas adsorbed by the second pretreatment device, and then pass it into the regenerative combustion device.

6. A regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 3 or 4, characterized in that, The first pretreatment device is equipped with a heating device.

7. A control method for a regenerative combustion system for fluctuating VOCs exhaust gas sources as described in any one of claims 1-6, characterized in that, The control method includes the following steps: S1. Exhaust gas enters the pretreatment system from the inlet pipe, and the control system obtains the inlet gas concentration C2 and the outlet gas concentration C1 of the pretreatment system. S2, The control system controls the preprocessing system according to C2 and C1: When C S1 ≤C2<C S2 Start the first preprocessing path, and then when C S1 ≤C1<C S2 Execute S3; When C S2 ≤C2<C S3 Enable the second preprocessing path, and then when C S1 ≤C1<C S2 Execute S3; When C S2 ≤C2<C S3 Enable the second and third preprocessing paths, and then when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 Enable the second preprocessing path, and then when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 Enable the second and third preprocessing paths, and then when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 The second preprocessing path is initiated, and the heating device of the first preprocessing unit is activated, thereby activating C. S1 ≤C1<C S2 Execute S3; When C2 < C S1 The second and fourth preprocessing paths are activated, and the heating device and heat exchange device of the first preprocessing unit are activated, thereby activating C. S1 ≤C1<C S2 Execute S3; S3. Exhaust gas enters the regenerative combustion device; Among them, C S1 <C S2 <C S3 ; The C S1 The first set value for exhaust gas concentration; the C S2 The second set value for exhaust gas concentration; the C S3 This is the third set value for exhaust gas concentration.

8. A control method for a regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 7, characterized in that, In step S2: When C S2 ≤C2<C S3 First, start the second preprocessing path, and then when C S2 ≤C1<C S3 Then start the third preprocessing path, and finally when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 First, start the second preprocessing path, and then when C1 < C S1 Then start the third preprocessing path, and finally when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 First, enable the second and third preprocessing paths, and then when C1 < C S1 Then close the third preprocessing path and turn on the heating device of the first preprocessing unit. Finally, when C S1 ≤C1<C S2 Execute S3; When C2 < C S1 First, the second preprocessing path is started, and then the heating device of the first preprocessing unit is turned on. Then, when C1 < C... S1 Then start the fourth pretreatment path and the heat exchange device, and finally when C S1 ≤C1<C S2 Execute S3.

9. A control method for a regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 7 or 8, characterized in that, In step S2: When C1≥C S2 , C S1 =Cmin, C S2 =1 / 8 LEL, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And 1 / 4 q < q t <3 / 4 q, C S1 =Cmin,C S2 =1 / 8 LEL, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And q t <1 / 4 q, C S1 =Cmin, 1.2 Cmin≤C S2 ≤2.0 Cmin, C S3 =1 / 4 LEL; When C S1 ≤C1<C S2 And q t >3 / 4 q, 2.0 Cmin≤C S1 ≤5.0 Cmin, C S2 =1 / 8 LEL, C S3 =1 / 4 LEL; Where Cmin is the minimum concentration required to maintain self-heating combustion in the regenerative combustion device, LEL is the minimum explosive limit of the exhaust gas, and q t This refers to the real-time VOCs adsorption capacity of the pretreatment system. ； Where t is the operating time of the pretreatment system, Q1 is the air volume of the pretreatment system, Q2 is the air volume of the pretreatment system, and q is the saturated adsorption capacity of the pretreatment system.

10. A control method for a regenerative combustion system for fluctuating VOCs exhaust gas sources according to claim 7 or 8, characterized in that, In step S2: The heating temperature of the heating device in the first pretreatment unit is T3, and ΔC1 = C. S1 -C1, the control system automatically adjusts T3 according to △C1: When △C1≤0, the heating device of the first pretreatment device is not turned on; 0<△C1≤500 mg / m 3 At that time, T3 = 40℃; 500 mg / m 3 <△C1≤1000 mg / m 3 At that time, T3 = 60℃; 1000 mg / m 3 <△C1≤2000 mg / m 3 At that time, T3 = 80℃; The gas temperature after processing by the heat exchange device is T4, the gas concentration at the outlet of the second pretreatment path is C3, and ΔC2=C S1 -C3, the control system automatically adjusts T4 according to △C2: When △C2≤0, the heat exchange device is not turned on; 0<△C2≤500 mg / m 3 At that time, T4 = 40℃; 500 mg / m 3 <△C2≤1000 mg / m 3 when T4=60°C; 1000 mg / m 3 <△C2≤2000 mg / m 3 when T4=80°C; 2000 mg / m 3 <ΔC2≤3000 mg / m 3 , T4=100°C; 3000 mg / m 3 <ΔC2≤4000 mg / m 3 , T4=120°C.

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