Heat storage combustion system for fluctuating VOCs waste gas source and control method of heat storage combustion system

Abstract

The invention provides a heat storage combustion system for a fluctuating VOCs waste gas source and a control method of the heat storage combustion system. The heat storage combustion system comprises a gas inlet pipeline, a pretreatment system, a heat storage combustion device and a control system. The pretreatment system comprises a plurality of pretreatment paths which are arranged in parallel and comprise a first pretreatment path, a second pretreatment path and a third pretreatment path; the control system comprises gas detection modules which are at least arranged at the inlet end and the outlet end of the pretreatment system and used for detecting parameters of waste gas entering the pretreatment system. Waste gas output by the gas inlet pipeline enters the pretreatment system, the control system obtains waste gas parameters through the gas detection module, a corresponding pretreatment path is started according to changes of the waste gas parameters, the waste gas concentration is treated to be within the target range, then the waste gas is introduced into the heat storage combustion device, and control over the heat storage combustion system is achieved. According to the method, peak clipping and valley filling type pretreatment is carried out on the fluctuating VOCs waste gas source, and the energy consumption of the system is reduced on the premise that the safety of the system is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of waste gas treatment, and particularly relates to a regenerative combustion system for fluctuant VOCs waste gas source and a control method thereof. BACKGROUND

[0002] With the increasing environmental protection pressure and VOCs rectification pressure faced by the fine chemical industry, collecting, summarizing and centrally treating the plant and production waste gas has become the choice of many chemical enterprises. As an end control technology, the regenerative thermal oxidizer (RTO) has been widely used in petrochemical industry, fine chemical industry, automobile coating and other industries.

[0003] The production processes of key industries such as medicine, chemical industry and petrochemical industry are complex, and most of them are intermittent production. The wind volume and concentration of VOCs waste gas fluctuate greatly, which has a great impact on the safe operation of RTO equipment. When the concentration is too low, the heat generated by the entering RTO equipment for combustion is low, and additional fuel or electric energy is needed, which increases the operation cost. When the concentration exceeds 25% of the lower limit of VOCs explosion, the system cannot timely process the waste gas with too high concentration, thereby producing a combustion and explosion safety risk. In addition, the waste gas incineration device has high investment, and enterprises generally do not equip multiple incineration devices. The collected waste gas has many types, complex composition, many production sources and large concentration fluctuation. The existing single RTO equipment is difficult to buffer the increased VOCs waste gas concentration in a short time, has great combustion and explosion safety risk, and leads to great safety hazards and high operation cost of RTO equipment.

[0004] Therefore, in view of the fluctuation of waste gas concentration, it is urgent to improve the safety and stability of the RTO system.

[0005] CN105879574A discloses a VOCs concentration load buffering and adjusting device, which is filled with adsorbent material. The adsorbent material can buffer and adjust the VOCs concentration load under normal temperature and pressure. The defect is that the fixed design of the buffering and adjusting device can only process a limited amount of waste gas, cannot accurately control the gas volume adsorbed and desorbed by the device, and cannot limit the over-saturation of the adsorption amount of the device. Therefore, it cannot be applied to the long-term operation and treatment of fluctuant VOCs waste gas source, and the treatment effect of fluctuant VOCs waste gas cannot meet the expectation.

[0006] CN119123440A discloses a new pretreatment process for high-concentration waste gas incineration in the hazardous waste industry, which includes the following steps: step one, waste gas enters a liquid seal system; step two, the liquid seal system processes the waste gas; step three, vacuum resolution; step four, waste gas recovery and liquid sealant regeneration; step five, RTO system processing. The invention reduces the concentration of high-concentration waste gas and increases the concentration of low-concentration waste gas by using the liquid seal system to process the waste gas according to its concentration. However, it cannot accurately control the amount of gas adsorbed and desorbed in the liquid seal system, and additional desorption of the liquid seal system is required, which increases the operating cost and affects the processing efficiency. The processing effect of fluctuating VOCs waste gas does not meet the expected results. SUMMARY

[0007] The present application aims to solve the problem of fluctuating VOCs waste gas concentration in the existing technology, which affects the safety and stability of the RTO system. Therefore, the present application provides a regenerative combustion system for fluctuating VOCs waste gas source and a control method thereof.

[0008] To achieve the above-mentioned purpose, the present application proposes the following technical solutions:

[0009] A regenerative combustion system for fluctuating VOCs waste gas source, comprising an air inlet pipeline, 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 air inlet pipeline, and the outlet end of the pretreatment system is connected to the inlet end of the regenerative combustion device;

[0010] The pretreatment system comprises a plurality of pretreatment paths arranged in parallel, and the pretreatment paths comprise a first pretreatment path, a second pretreatment path and a third pretreatment path.

[0011] The control system comprises a gas detection module, which is arranged at least at the inlet end and outlet end of the pretreatment system for detecting the waste gas parameters entering the pretreatment system.

[0012] The waste gas output by the air inlet pipeline enters the pretreatment system, the control system obtains the waste gas parameters through the gas detection module, and according to the change of the waste gas parameters, the corresponding pretreatment path is enabled to process the waste gas concentration to the target range, and then it is introduced into the regenerative combustion device, thereby realizing the control of the regenerative combustion system.

[0013] Specifically, the waste gas parameters detected by the gas detection module include but are not limited to waste gas volume, gas flow rate, waste gas concentration and waste gas temperature.

[0014] Specifically, the target range of waste gas concentration is within the concentration range that can meet the self-heating and safety of the regenerative combustion device without explosion risk.

[0015] Further, the first pre-treatment path comprises a first pipeline;

[0016] The first pipeline inlet end is connected with the inlet pipeline outlet end, and the first pipeline outlet end is connected with the regenerative combustion device inlet end, so that the first pre-treatment path can directly lead the exhaust gas into the regenerative combustion device.

[0017] Further, the second pre-treatment path comprises a second pipeline, a first pre-treatment device and a third pipeline;

[0018] The second pipeline inlet end is connected with the inlet pipeline outlet end, the second pipeline outlet end is connected with the first pre-treatment device input end, the third pipeline inlet end is connected with the first pre-treatment device output end, and the third pipeline outlet end is connected with the regenerative combustion device inlet end;

[0019] The second pre-treatment path is used for adsorbing or desorbing the exhaust gas through the first pre-treatment device, and then leading the exhaust gas into the regenerative combustion device.

[0020] Further, the third pre-treatment path comprises a fourth pipeline, a second pre-treatment device and a fifth pipeline;

[0021] The fourth pipeline inlet end is connected with the first pre-treatment device output end, the fourth pipeline outlet end is connected with the second pre-treatment device input end, the fifth pipeline inlet end is connected with the second pre-treatment device output end, and the fifth pipeline outlet end is connected with the regenerative combustion device inlet end;

[0022] The third pre-treatment path is used for adsorbing or desorbing the exhaust gas through the second pre-treatment device after the exhaust gas passes through the first pre-treatment device, and then leading the exhaust gas into the regenerative combustion device.

[0023] Further, the pre-treatment system further comprises a fourth pre-treatment path, the fourth pre-treatment path comprising a sixth pipeline, a heat exchange device, a seventh pipeline and an eighth pipeline;

[0024] The sixth pipeline inlet end is connected with the regenerative combustion device outlet end, the sixth pipeline outlet end is connected with the heat exchange device input end, the seventh pipeline inlet end is connected with the heat exchange device output end, the seventh pipeline outlet end is connected with the second pre-treatment device input end, the eighth pipeline inlet end is connected with the second pre-treatment device output end, and the eighth pipeline outlet end is connected with the regenerative combustion device inlet end;

[0025] The fourth pre-treatment path is used for desorbing the exhaust gas adsorbed by the second pre-treatment device after leading the hot gas stream from the regenerative combustion device, and then leading the exhaust gas into the regenerative combustion device.

[0026] Specifically, the heat exchange device is externally connected with a circulating water cooling device or a circulating air cooling device.

[0027] The heat exchange device realizes heat exchange calculation by controlling the flow rate of the externally connected air or water, thereby regulating the temperature of the hot gas stream passing through the heat exchange device. The externally connected cold source can be used for heating after passing through the heat exchange device.

[0028] The hot gas stream passing through the heat exchange device enters the second pretreatment device in the fourth pretreatment path, and the adsorbed VOCs gas in the second pretreatment device is released slowly. The amount of gas introduced by the sixth pipeline and the flow rate of the externally connected cold source of the heat exchange device can be regulated to regulate the amount and temperature of the hot gas entering the second pretreatment device, thereby regulating the slow release speed and concentration of the adsorbed gas in the second pretreatment device.

[0029] Specifically, the types of the first pretreatment device and the second pretreatment device can be selected according to factors such as the type of the waste gas source, including but not limited to a pretreatment adsorption tower and a pretreatment adsorber.

[0030] The pretreatment adsorption tower includes but is not limited to a packed tower, and the pretreatment adsorber includes but is not limited to a fixed bed.

[0031] The absorption liquid in the absorption tower can be selected from water, white oil, glycerol, NMP, etc. according to the type of the waste gas source. The electric heater installed at the bottom of the absorption tower can heat the absorption liquid to promote the slow release of the absorbed VOCs gas in the absorption liquid. The adsorbent in the adsorber can be selected from granular activated carbon, honeycomb activated carbon, zeolite honeycomb, hollow strip molecular sieve, and macroporous resin according to the type of the waste gas source.

[0032] Preferably, the liquid-gas ratio of the pretreatment absorption tower during operation is < 4 L / m 3 , the empty tower gas velocity is < 2 m / s, and the residence time is > 2 s; the waste gas residence time of the pretreatment adsorber during operation is 0.5-2 s, and the gas flow rate is 0.1-1.2 m / s.

[0033] Specifically, by controlling the liquid-gas ratio and gas flow rate of the pretreatment device, the residence time of the waste gas in the absorption tower is ensured, the adsorption time of high-concentration waste gas and the slow release time of low-concentration waste gas are ensured, and sufficient buffer time is ensured for regulating the concentration of the waste gas.

[0034] Further, the first pretreatment device is provided with a heating device.

[0035] Specifically, the control system regulates the slow release amount of the gas in the pretreatment device by regulating the heating temperature, thereby realizing precise control of the output concentration of the waste gas.

[0036] A control method of a regenerative combustion system for fluctuating VOCs waste gas sources, comprising the following steps:

[0037] S1, the exhaust gas from the intake pipeline into the pretreatment system, the control system to obtain the pretreatment system intake concentration C2, exhaust concentration C1;

[0038] S2, the control system according to C2 and C1 control the pretreatment system:

[0039] When C S1 ≤C2<C S2 , open the first pretreatment path, and then when C S1 ≤C1<C S2 , S3 is executed;

[0040] When C S2 ≤C2<C S3 , open the second pretreatment path, and then when C S1 ≤C1<C S2 , S3 is executed;

[0041] When C S2 ≤C2<C S3 , open the second pretreatment path and the third pretreatment path, and then when C S1 ≤C1<C S2 , S3 is executed;

[0042] When C2<C S1 , open the second pretreatment path, and then when C S1 ≤C1<C S2 , S3 is executed;

[0043] When C2<C S1 , open the second pretreatment path and the third pretreatment path, and then when C S1 ≤C1<C S2 , S3 is executed;

[0044] When C2<C S1 , open the second pretreatment path, and open the first pretreatment device heating device, and then when C S1 ≤C1<C S2 , S3 is executed;

[0045] When C2<C S1 , open the second pretreatment path and the fourth pretreatment path, and open the first pretreatment device heating device and heat exchange device, and then when C S1 ≤C1<C S2 , S3 is executed;

[0046] S3, the exhaust gas into the regenerative combustion device;

[0047] Wherein, C S1 <C S2 <C S3 ;

[0048] the C S1 is a first set value of exhaust gas concentration; the C S2 is a second set value of exhaust gas concentration; the C S3 is a third set value of exhaust gas concentration.

[0049] Further, in the step S2:

[0050] When C S2 ≤ C2 < C S3 , the second pretreatment path is first opened, and then when C S2 ≤ C1 < C S3 , the third pretreatment path is opened, and finally when C S1 ≤ C1 < C S2 , S3 is executed.

[0051] When C2 < C S1 , the second pretreatment path is first opened, and then when C1 < C S1 , the third pretreatment path is opened, and finally when C S1 ≤ C1 < C S2 , S3 is executed.

[0052] When C2 < C S1 , the second pretreatment path and the third pretreatment path are first opened, and then when C1 < C S1 , the third pretreatment path is closed and the first pretreatment device heating device is opened, and finally when C S1 ≤ C1 < C S2 , S3 is executed.

[0053] When C2 < C S1 , the second pretreatment path is first opened and the first pretreatment device heating device is opened, and then when C1 < C S1 , the fourth pretreatment path is opened and the heat exchange device is opened, and finally when C S1 ≤ C1 < C S2 , S3 is executed.

[0054] Further, in the step S2:

[0055] When C1 ≥ C S2 , C S1 = Cmin, C S2 = 1 / 8 LEL, C S3 = 1 / 4 LEL;

[0056] When C S1 ≤ C1 < C S2 and 1 / 4 q < q t < 3 / 4 q, C S1 = Cmin, C S2 = 1 / 8 LEL, CS3 = 1 / 4 LEL;

[0057] 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;

[0058] 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;

[0059] Wherein Cmin is the minimum concentration to maintain self-heat combustion of the regenerative combustion device, LEL is the minimum explosion limit value of exhaust gas, q t is the real-time VOCs adsorption capacity of the pretreatment system;

[0060]

[0061] Wherein t is the operation 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, i.e. the experimental value under the same working condition in the laboratory for specific pollutant.

[0062] Specifically, Cmin is set according to the components, concentration ratio and heat value of the exhaust gas source, and LEL is specifically the minimum concentration limit of the exhaust gas in air to cause explosion when encountering open flame.

[0063] 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 is linked with the inlet concentration C1 of the regenerative combustion device.

[0064] In the process of "peak clipping and valley filling" of the input waste gas by the pretreatment system, when the real-time VOCs adsorption amount of the system is low, the second set value is reduced to increase the VOCs storage amount of the system by reducing the VOCs slow-release amount of the pretreatment system; when the real-time VOCs adsorption amount of the system is high and there is a risk of oversaturation, the first set value is increased to reduce the VOCs storage amount of the system by increasing the VOCs slow-release amount of the pretreatment system, so as to ensure that the VOCs adsorption amount in the pretreatment system is always maintained at a safe level, which not only meets the self-heating demand of the regenerative combustion device, but also avoids the adsorption oversaturation of the pretreatment device, which leads to the need for overall circulation desorption or replacement of the pretreatment system.

[0065] Specifically, in the execution process of the above control method, the control system detects and regulates the VOCs storage amount in the pretreatment system to always maintain between 1 / 4 and 3 / 4 of the saturated adsorption capacity of the system, so as to ensure that there is always sufficient buffer margin in the pretreatment system to cope with sudden increases in the concentration of the waste gas source.

[0066] Further, in the step S2:

[0067] The heating temperature of the heating device of the first pretreatment device is T3, and ΔC1=C S1 -C1, and the control system automatically regulates T3 according to ΔC1:

[0068] When ΔC1≤0, the heating device of the first pretreatment device is not started;

[0069] When 0<ΔC1≤500mg / m 3 , T3=40℃;

[0070] When 500mg / m 3 <ΔC1≤1000mg / m 3 , T3=60℃;

[0071] When 1000mg / m 3 <ΔC1≤2000mg / m 3 , T3=80℃;

[0072] The temperature of the treated gas by the heat exchange device is T4, the concentration of the outlet gas of the second pretreatment path is C3, and ΔC2=C S1 -C3, and the control system automatically regulates T4 according to ΔC2:

[0073] When ΔC2≤0, the heat exchange device is not started;

[0074] When 0<ΔC2≤500mg / m 3 , T4=40℃;

[0075] When 500mg / m 3< ΔC2≤ 1000 mg / m 3 T4 = 60 °C when

[0076] 1000 mg / m 3 < ΔC2≤ 2000 mg / m 3 T4 = 80 °C when

[0077] 2000 mg / m 3 < ΔC2≤ 3000 mg / m 3 T4 = 100 °C when

[0078] 3000 mg / m 3 < ΔC2≤ 4000 mg / m 3 T4 = 120 °C when

[0079] Specifically, in step S2, when the second pretreatment path is enabled, the value of T3 is dynamically regulated 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 enabled at the same time, the values of T3 and T4 are dynamically regulated 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 to within the safety set value range and the storage amount of the exhaust gas in the pretreatment system is dynamically stable.

[0080] The specific mechanism of the above control method is as follows:

[0081] When the inlet gas concentration reaches the first set value for maintaining self-heat combustion of the regenerative combustion device, the system automatically opens the first pretreatment path to directly introduce the regenerative combustion device for combustion, at this time, the self-heat combustion of the regenerative combustion device is realized, and no additional energy supply is needed.

[0082] When the inlet gas concentration reaches the second set value, the system automatically opens the second pretreatment path or the third pretreatment path to store part of the exhaust gas in the pretreatment system, and the high-concentration exhaust gas is adsorbed by the pretreatment system to ensure its safety and stability, and is maintained within the concentration range that maintains the self-heat combustion of the regenerative combustion device and does not produce explosion hazards, thereby realizing the "peak clipping" treatment of high-concentration exhaust gas.

[0083] When the inlet concentration is lower than the first set value, the system automatically opens the second pretreatment path or the third pretreatment path, and the waste gas stored in the pretreatment system is released slowly through normal temperature stripping or heating to increase the concentration of the waste gas source, so that the concentration of the waste gas entering the regenerative combustion device can be maintained to realize self-heating combustion; in order to save energy and further increase the amount of slowly released waste gas, the fourth pretreatment path can be opened to lead the hot gas stream from the regenerative combustion device into the heat exchange device, and the temperature of the waste gas entering the second pretreatment device is adjusted through the heat exchange device, so as to adjust the speed and concentration of the slowly released gas of the second pretreatment device, so as to realize the increase of the concentration of the waste gas entering the regenerative combustion exhaust system through the fourth pretreatment path, and realize the "filling valley" treatment of low-concentration waste gas.

[0084] The beneficial effects of the present application are:

[0085] (1) The regenerative combustion system of the present application adopts a multi-stage pretreatment system of absorption / adsorption or combination thereof, and combines the first pretreatment path, the second pretreatment path, the third pretreatment path and the fourth pretreatment path which are optimally arranged, to realize the "peak clipping and valley filling" pretreatment for the fluctuating VOCs waste gas source, so as to ensure that the waste gas entering the regenerative combustion device always maintains within the concentration range meeting the self-heating and safety, and reduce the energy consumption of the system under the premise of ensuring the safety of the system; stable combustion conditions further improve the waste gas purification efficiency, and also avoid the environmental risk problem caused by emergency discharge when the concentration of the waste gas source is higher than 1 / 4 of the explosion limit.

[0086] (2) The regenerative combustion system of the present application realizes the dynamic regulation of the waste gas adsorption amount in the pretreatment system through the cooperation of the control system and the control method, avoids the recovery and circulation of the waste gas adsorption amount of the pretreatment device after saturation, realizes the simplified design of the regenerative combustion pretreatment system, saves the processing steps, shortens the working condition, and is suitable for long-term uninterrupted operation and treatment of fluctuating VOCs waste gas source, and reduces the number of shutdown processing or maintenance.

[0087] (3) The regenerative combustion system and the control method thereof of the present application solve the environmental and safety risks caused by the large fluctuation of waste gas concentration in the key industries such as medicine, chemical industry and petrochemical industry, greatly improve the purification efficiency of the RTO system, reduce the energy consumption of the system, and can be applied to the treatment of large amount of waste gas.

[0088] It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be seen as part of the subject matter of the present disclosure provided such concepts are not mutually inconsistent.

[0089] The foregoing and other aspects, embodiments and features of the present teachings can be better understood from the following description of the present teachings with reference to the drawings. Other aspects, embodiments and features of the present teachings will be apparent from the following description of the examples and appended claims, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0090] The drawings are not drawn to scale. In the drawings, each same or similar component will be denoted by the same reference signs throughout the several drawings. For the sake of clarity, not every component is labeled in every drawing. Embodiments of various aspects of the present teachings will now be described, by way of example only, with reference to the accompanying drawings in which:

[0091] Figure 1 is a schematic diagram of a regenerative combustion system for fluctuating VOCs waste gas sources provided by the present teachings;

[0092] Figure 2 is a flowchart of a control method of the regenerative combustion system for fluctuating VOCs waste gas sources provided by the present teachings. DETAILED DESCRIPTION

[0093] In order to make the objects, technical solutions and advantages of the embodiments of the present teachings clearer, the technical solutions of the embodiments of the present teachings will be described below in connection with the drawings of the embodiments of the present teachings. Obviously, the described embodiments are only a part of the embodiments of the present teachings, rather than all the embodiments. Based on the described embodiments of the present teachings, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present teachings. Unless otherwise defined, the technical terms or scientific terms used herein should be understood as their common meanings to those having ordinary skills in the art to which the present teachings belong.

[0094] The terms "first", "second", and similar terms used in the specification and claims of the present patent application do not denote any order, quantity, or importance, but are used to distinguish different components. Similarly, the singular forms "a", "an", and "the" do not denote a quantity restriction unless the context clearly indicates otherwise. The terms "comprise", "comprises", and similar terms mean that the elements or objects before the term "comprise" or "comprises" encompass the features, integers, steps, operations, elements, and / or components listed after the term "comprise" or "comprises", and do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positions, and may change accordingly when the absolute positions of the described objects change.

[0095] Referring to the drawings Figure 1 The embodiment provides a regenerative combustion system for a fluctuating VOCs waste gas source, and specifically comprises: a gas inlet pipeline, a pretreatment system, a regenerative combustion device, and a control system arranged in sequence. In general, the inlet end of the pretreatment system is connected to the outlet end of the gas inlet pipeline, and the outlet end of the pretreatment system is connected to the inlet end of the regenerative combustion device.

[0096] The gas inlet pipeline is connected to the waste gas source and is used to input waste gas into the pretreatment system. A fan is arranged on the gas inlet pipeline.

[0097] The pretreatment system comprises a plurality of pretreatment paths arranged in parallel, and the pretreatment paths comprise a first pretreatment path, a second pretreatment path, and a third pretreatment path.

[0098] The control system comprises a first gas detection module, a second gas detection module, a third gas detection module, a mass flow controller, and a circulating water cooling device. The first gas detection module is arranged at the outlet end of the pretreatment system, and the second gas detection module is arranged at the inlet end of the pretreatment system and is used to detect the parameters of waste gas entering the pretreatment system.

[0099] An exhaust pipeline is arranged at the outlet end of the regenerative combustion system and is used to discharge the safe gas after combustion.

[0100] The first pretreatment path comprises a first pipeline. The inlet end of the first pipeline is connected to the outlet end of the gas inlet pipeline, and the outlet end of the first pipeline is connected to the inlet end of the regenerative combustion device.

[0101] A first valve is arranged on the first pipeline.

[0102] The first pretreatment path is used to directly input waste gas into the regenerative combustion device.

[0103] The second pretreatment path comprises a second pipeline, a first pretreatment device and a third pipeline; the inlet end of the second pipeline is connected with the outlet end of the air inlet pipeline, the outlet end of the second pipeline is connected with the input end of the first pretreatment device, the inlet end of the third pipeline is connected with the output end of the first pretreatment device, and the outlet end of the third pipeline is connected with the inlet end of the heat accumulation combustion device.

[0104] A second valve is arranged on the second pipeline, a third valve is arranged on the third pipeline, and a third gas detection module is arranged at the front end of the third pipeline and used for detecting the gas parameter of the second pretreatment path.

[0105] The second pretreatment path is used for adsorbing or desorbing the exhaust gas by the first pretreatment device and then introducing the exhaust gas into the heat accumulation combustion device.

[0106] The third pretreatment path comprises a fourth pipeline, a second pretreatment device and a fifth pipeline; the inlet end of the fourth pipeline is connected with the output end of the first pretreatment device, the outlet end of the fourth pipeline is connected with the input end of the second pretreatment device, the inlet end of the fifth pipeline is connected with the output end of the second pretreatment device, and the outlet end of the fifth pipeline is connected with the inlet end of the heat accumulation combustion device.

[0107] A fourth valve is arranged on the fourth pipeline, and a fifth valve is arranged on the fifth pipeline.

[0108] In order to save material cost and simplify the pipeline design, the inlet end of the fourth pipeline is connected to the middle end of the third pipeline, which is located between the third gas detection module and the third valve.

[0109] The third pretreatment path is used for adsorbing or desorbing the exhaust gas by the first pretreatment device through the second pretreatment device and then introducing the exhaust gas into the heat accumulation combustion device.

[0110] The pretreatment system further comprises a fourth pretreatment path, the fourth pretreatment path comprises a sixth pipeline, a heat exchange device, a seventh pipeline and an eighth pipeline; the inlet end of the sixth pipeline is connected with the outlet end of the heat accumulation combustion device, the outlet end of the sixth pipeline is connected with the input end of the heat exchange device, the inlet end of the seventh pipeline is connected with the output end of the heat exchange device, the outlet end of the seventh pipeline is connected with the input end of the second pretreatment device, the inlet end of the eighth pipeline is connected with the output end of the second pretreatment device, and the outlet end of the eighth pipeline is connected with the inlet end of the heat accumulation combustion device.

[0111] A sixth valve is arranged on the sixth pipeline and used for leading out the safe hot gas stream after combustion from the heat accumulation combustion device; a mass flow control meter is arranged at the sixth valve and used for controlling the opening degree of the sixth valve and accurately controlling the gas amount entering the heat exchange device.

[0112] A seventh valve is arranged on the seventh pipeline, and an eighth valve is arranged on the eighth pipeline.

[0113] The heat exchange device is externally connected with a circulating water cooling device, the efficiency of the heat exchange device is adjusted by adjusting the flow of the circulating water cooling device, and the control system adjusts the flow of the circulating water cooling device and the opening degree of the sixth valve, so as to accurately control the temperature and gas volume of the waste gas passing through the heat exchange device.

[0114] The temperature of the hot gas flow treated by the heat exchange device ranges from 40 to 120 DEG C, the lower the outlet gas concentration of the pretreatment system is, the higher the temperature of the hot gas flow treated by the heat exchange device is.

[0115] The fourth pretreatment path is used for leading the hot gas flow out of the regenerative combustion device to desorb the waste gas adsorbed by the second pretreatment device, and then into the regenerative combustion device.

[0116] The first, second and third gas detection modules are used for detecting the parameters of the passing gas in real time, including but not limited to concentration, temperature and gas volume, and commercially available gas detectors or sensors can be used, including but not limited to photoionization detector (PID), portable flame ionization detector (FID), lower explosive limit detector (LEL) and the like.

[0117] The first pretreatment device is a packed tower type pretreatment absorption tower, and the liquid-gas ratio of the pretreatment absorption tower is less than 4 L / m 3 when the pretreatment absorption tower is running, the empty tower gas velocity is less than 2 m / s, and the residence time is greater than 2 s. According to actual needs, two or more pretreatment absorption towers in series or parallel can be arranged at the position of the first pretreatment device.

[0118] The bottom of the pretreatment absorption tower is provided with an electric heater, and the control system controls the switch and heating temperature of the electric heater. The heating temperature of the electric heater of the pretreatment absorption tower is 40-80 DEG C, and the lower the outlet gas concentration of the pretreatment system is, the higher the heating temperature of the electric heater is.

[0119] The second pretreatment device is a fixed bed type pretreatment adsorber, and the residence time of the waste gas in the pretreatment adsorber is 0.5-2 s and the gas flow rate is 0.1-1.2 m / s when the pretreatment adsorber is running. According to actual needs, two or more pretreatment adsorbers in series or parallel can be arranged at the position of the second pretreatment device.

[0120] By controlling the gas flow rate and residence time in the pretreatment device, sufficient buffer time is provided for the pretreatment system to treat the waste gas, so as to facilitate timely adjustment in case of large waste gas concentration fluctuation.

[0121] In summary, the exhaust gas enters the pretreatment system through the intake pipeline, the control system obtains the exhaust gas parameters through the gas detection module, and according to the change of the exhaust gas parameters, the corresponding pretreatment path is started, the exhaust gas adsorption and desorption amount of the pretreatment system is controlled through the electric heater, the mass flow controller and the circulating water cooling device, the exhaust gas concentration is processed to the target range, and then it is input into the regenerative combustion device to realize the control of the regenerative combustion system.

[0122] The target range value is usually set to be within the concentration range that meets the self-heating and safety of the regenerative combustion device and has no explosion risk. The above-mentioned concentration range is set as an initial safety range, and the target range value can be dynamically adjusted according to the real-time VOCs adsorption amount of the pretreatment system, so as to ensure that the exhaust gas concentration entering the regenerative combustion device always remains within the initial safety range, and at the same time, the pretreatment system also has no risk of oversaturation, and there is no need to replace or stop for maintenance.

[0123] Referring to the accompanying drawings Figure 2 , the embodiment also provides a control method of the regenerative combustion system for the fluctuating VOCs exhaust gas source, which specifically includes a safety mode, a peak shaving mode and a valley filling mode, wherein the peak shaving mode and the valley filling mode adopt a multi-stage pretreatment mode to dynamically regulate and control the concentration of the unstable exhaust gas source.

[0124] Safety mode:

[0125] Mode one, the exhaust gas concentration is within the range that maintains self-heating combustion and safety, and the first pretreatment path is adopted

[0126] The fan is started, the exhaust gas enters the pretreatment system through the intake pipeline, 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 is opened, and the exhaust gas enters the regenerative combustion device through the first pretreatment path.

[0127] Peak shaving mode:

[0128] Mode two, the exhaust gas concentration is high, and the second pretreatment path is adopted

[0129] The fan is started, the exhaust gas enters the pretreatment system through the intake pipeline, 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 pretreatment mode is started, and the second valve and the third valve are opened, and part of the exhaust gas is stored in the first pretreatment device.

[0130] 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.

[0131] Mode three, the exhaust gas concentration is extremely high, and the third pretreatment path is adopted

[0132] Turning on the fan, the exhaust gas enters the pretreatment system through the inlet pipeline, 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 pretreatment mode is enabled, and the second valve and the third valve are opened, and part of the exhaust gas is stored in the first pretreatment device.

[0133] When 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 pretreatment mode is enabled again.

[0134] Close the third valve, and open the fourth valve and the fifth valve, and part of the exhaust gas is stored in the first pretreatment device and the second pretreatment device.

[0135] 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.

[0136] Valley filling mode:

[0137] Mode four, the exhaust gas concentration is low, the second pretreatment path is adopted, and the first pretreatment mode is adopted

[0138] Turning on the fan, the exhaust gas enters the pretreatment system through the inlet pipeline, when the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first pretreatment mode is enabled, and the second valve and the third valve are opened, and the exhaust gas stored in the first pretreatment device is released slowly through normal temperature stripping.

[0139] 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.

[0140] Mode five, the exhaust gas concentration is extremely low, the third pretreatment path is adopted, and the second pretreatment mode is adopted

[0141] Turning on the fan, the exhaust gas enters the pretreatment system through the inlet pipeline, when the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first pretreatment mode is enabled, and the second valve and the third valve are opened, and the exhaust gas stored in the first pretreatment device is released slowly through normal temperature stripping.

[0142] 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 second pretreatment mode is enabled again.

[0143] Close the third valve, and open the fourth valve and the fifth valve, and part of the exhaust gas is stored in the first pretreatment device and the second pretreatment device.

[0144] 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.

[0145] Mode six, the exhaust gas concentration is extremely low, using the second pretreatment path, three-stage pretreatment mode

[0146] The fan is turned on, the exhaust gas enters the pretreatment system through the air inlet pipeline, when the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first-stage pretreatment mode is enabled, the second valve and the third valve are opened, and the exhaust gas stored in the first pretreatment device is released slowly by normal temperature stripping.

[0147] 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 second-stage pretreatment mode is enabled.

[0148] The third valve is closed, and the fourth valve and the fifth valve are opened, so that the exhaust gas stored in the first pretreatment device and the second pretreatment device is released slowly by normal temperature stripping.

[0149] When the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the third-stage pretreatment mode is enabled.

[0150] The fourth valve and the fifth valve are closed, the third valve is opened, the first pretreatment device heating device is turned on, the exhaust gas stored in the first pretreatment device is released slowly by heating, and the exhaust gas concentration is adjusted by adjusting the heating temperature.

[0151] 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.

[0152] Mode seven, the exhaust gas concentration is extremely low, and the second pretreatment path and the fourth pretreatment path are used simultaneously, four-stage pretreatment mode

[0153] The fan is turned on, the exhaust gas enters the pretreatment system through the air inlet pipeline, when the second gas detection module detects that the exhaust gas concentration is lower than the first set value, the first-stage pretreatment mode is enabled, the second valve and the third valve are opened, and the exhaust gas stored in the first pretreatment device is released slowly by normal temperature stripping.

[0154] 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 second-stage pretreatment mode is enabled.

[0155] The third valve is closed, and the fourth valve and the fifth valve are opened, so that the exhaust gas stored in the first pretreatment device and the second pretreatment device is released slowly by normal temperature stripping.

[0156] When the first gas detection module detects that the exhaust gas concentration is still lower than the first set value, the third pretreatment mode is enabled.

[0157] The fourth valve and the fifth valve are closed, the third valve is opened, the first pretreatment device heating device is turned on, the exhaust gas stored in the first pretreatment device is released slowly by heating, and the slow release gas concentration is adjusted by controlling the heating temperature.

[0158] 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 pretreatment mode is enabled again.

[0159] The sixth valve, the seventh valve and the eighth valve are opened at the same time, the hot gas stream is led out from the regenerative combustion device, enters the second pretreatment device for exhaust gas slow release after temperature reduction treatment through the heat exchange device, and the hot gas temperature and flow entering the second pretreatment device are precisely controlled by adjusting the gas amount discharged by the sixth valve and the cold source flow of the heat exchange device, so as to control the slow release gas concentration of the second pretreatment device.

[0160] 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.

[0161] Wherein, the pretreatment system inlet gas concentration and gas amount are C2 and Q2 respectively, the outlet gas concentration and gas amount are C1 and Q1 respectively, the concentration and gas amount of the gas passing through the first gas detection module are C1 and Q1 respectively, the concentration and gas amount of the gas passing through the second gas detection module are C2 and Q2 respectively, the concentration and gas amount of the gas passing through the third gas detection module are C3 and Q3 respectively, the electric heater heating temperature of the first pretreatment device is T3, which is detected by the third gas detection module, the gas temperature after the heat exchange device treatment is T4, the sixth valve controls the passing gas amount Q4, and the system control is 1 / 20Q2≤Q4≤1 / 5Q2.

[0162] When the second pretreatment path is enabled alone, the data detected by the first gas detection module and the third gas detection module are the same.

[0163] During the execution of the above method, the first set value, the second set value and the third set value change with the real-time VOCs adsorption amount q of the pretreatment system. t So as to control the VOCs adsorption amount in the pretreatment system, prevent it from being too small so as to be unable to perform the above filling mode, and prevent it from being too much to cause the pretreatment device to be oversaturated and unable to continue to adsorb gas.

[0164] The real-time VOCs storage amount of the pretreatment system is:

[0165] Wherein t is the running time of the pretreatment system, Q1 is the exhaust gas flow detected by the first gas detection module, Q2 is the exhaust gas flow detected by the second gas detection module, and q is the saturated adsorption capacity of the pretreatment system, i.e. the experimental value under the same working condition in the laboratory for a specific pollutant.

[0166] During the execution of the above method, the VOCs storage amount of the pretreatment system is kept at 1 / 4q t <3 / 4q as much as possible, so that the pretreatment system has more buffer margin while performing peak clipping and valley filling type pretreatment on unstable exhaust gas sources, ensuring that the VOCs storage amount of the pretreatment device in the pretreatment system is within a safe range and ensuring that the pretreatment device does not become saturated with adsorbed gas.

[0167] If the gas concentration fluctuates too much or other conditions occur, causing the VOCs storage amount of the pretreatment system to exceed the safe range of 1 / 4q

[0168] When C1≥C S1 , C S1 =Cmin, C S2 =1 / 8LEL, and C S3 =1 / 4LEL.

[0169] When C S1 ≤C1<C S2 and 1 / 4q t <3 / 4q, C S1 =Cmin, C S2 =1 / 8LEL, and C S3 =1 / 4LEL.

[0170] When C S1 ≤C1<C S2 and q t <1 / 4q, C S1 =Cmin, 1.2Cmin≤C S2 ≤2.0Cmin, and C S3 =1 / 4LEL.

[0171] When C S1 ≤C1<C S2 and q t >3 / 4q, 2.0Cmin≤C S1 ≤5.0Cmin, C S2 =1 / 8LEL, and C S3 =1 / 4LEL.

[0172] Wherein Cmin is the minimum concentration to maintain the self-supply heat combustion of the RTO regenerative combustion device, the specific value is set according to the components, concentration ratio and heat value of the waste gas source, and LEL is the minimum explosion limit value of the waste gas, which is the minimum concentration limit of the waste gas in the air to cause explosion when encountering open flame.

[0173] During the execution of the above method, when the first pretreatment mode is used for slow release of the gas, 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 gas concentration of the regenerative combustion device and the VOCs adsorption amount of the pretreatment system, to ensure that the gas released by heating is maintained at a value that can maintain the self-supply heat combustion of the regenerative combustion device and does not exceed the safety limit, while ensuring that the amount of waste gas adsorbed in the first pretreatment device in real time is maintained within an appropriate range, avoiding the occurrence of too little or oversaturation.

[0174] The third gas detection module detects the waste gas temperature T3, which is the heating temperature of the heating device of the first pretreatment device, and ΔC1 = C S1 -C1, the system automatically controls T3 according to ΔC1:

[0175] When ΔC1≤0, the heating device of the first pretreatment device is not started;

[0176] When 0<ΔC1≤500mg / m 3 , T3 = 40℃;

[0177] When 500mg / m 3 <ΔC1≤1000mg / m 3 , T3 = 60℃;

[0178] When 1000mg / m 3 <ΔC1≤2000mg / m 3 , T3 = 80℃;

[0179] During the execution of the above method, when the hot gas stream after combustion is introduced from the regenerative combustion device to slow release the waste gas in the second pretreatment device, the amount and temperature of the hot gas introduced into the second pretreatment device are jointly controlled by the opening degree of the sixth valve and the flow of the cold source of the heat exchange device, to accurately control the temperature of the hot gas after being treated by the heat exchange device and entering the second pretreatment device, and further control the concentration of the waste gas released by heating in the second pretreatment device. This control method is a mature technology, and will not be described in detail here.

[0180] The concentration of the gas released by the second pretreatment device is linked to the concentration of the gas released by heating in the first pretreatment device. When the concentration of the gas released by the first pretreatment device is insufficient, the system controls the release temperature of the second pretreatment device to be increased, so as to release more gas for filling operation.

[0181] The temperature of the treated gas by the heat exchange device is T4, which is the temperature of the gas entering the second pretreatment device via the RTO heat recovery path. A gas temperature detection device can be provided at the seventh valve to detect T4, and ΔC2 = C S1 -C3, the system automatically controls T4 according to ΔC2:

[0182] When ΔC2≤0, the heat exchange device is not turned on.

[0183] When 0<ΔC2≤500mg / m 3 , T4=40℃.

[0184] When 500mg / m 3 <ΔC2≤1000mg / m 3 , T4=60℃.

[0185] When 1000mg / m 3 <ΔC2≤2000mg / m 3 , T4=80℃.

[0186] When 2000mg / m 3 <ΔC2≤3000mg / m 3 , T4=100℃.

[0187] When 3000mg / m 3 <ΔC2≤4000mg / m 3 , T4=120℃.

[0188] Example 1

[0189] A regenerative combustion system for a fluctuating VOCs waste gas source, the devices used are as shown in the accompanying Figure 1 .

[0190] The adsorbent material in the first pretreatment device is water, and the dynamic adsorption capacity of reversible adsorption and desorption is 35mg / g. During operation, the liquid-gas ratio is 3L / m 3 , the empty tower gas velocity is 1.5m / s, and the residence time is 2.5s. The adsorbent material in the second pretreatment device is honeycomb activated carbon, and the dynamic adsorption capacity of reversible adsorption and desorption is 160mg / g. During operation, the waste gas residence time is 1s, and the gas flow rate is 1m / s.

[0191] The regenerative combustion device is a three-chamber RTO.

[0192] The first, second, and third gas detection modules are FID and mass flow controllers, which can detect gas concentration and flow rate.

[0193] The mass flow controller is a thermal gas mass control flow meter.

[0194] The heat exchange device is a plate heat exchanger.

[0195] The regenerative combustion system operates at normal temperature and pressure according to the control method shown in the accompanying Figure 2 The VOCs exhaust gas source has a concentration of 500-12000 mg / m 3 , and the concentration of the exhaust gas treated by the pretreatment system is 3000-6000 mg / m 3 . The overall system has been continuously and stably operated for more than one week without any abnormality, and the exhaust gas discharged by the regenerative combustion device meets the environmental protection requirements.

[0196] Example 2

[0197] A regenerative combustion system for a fluctuating VOCs exhaust gas source, the devices used are shown in the accompanying Figure 1 .

[0198] The adsorbent material in the first pretreatment device is water, and the dynamic adsorption capacity of the reversible adsorption and desorption is 35 mg / g. The liquid-gas ratio during operation is 3 L / m 3 , the empty tower gas velocity is 1.5 m / s, and the residence time is 2.5 s. The adsorbent material in the second pretreatment device is granular activated carbon, and the dynamic adsorption capacity of the reversible adsorption and desorption is 278 mg / g. The residence time of the exhaust gas during operation is 1 s, and the gas flow rate is 0.5 m / s.

[0199] The regenerative combustion device is a three-chamber RTO.

[0200] The first, second, and third gas detection modules are FID and mass flow controllers, which can detect gas concentration and flow rate.

[0201] The mass flow controller is a thermal gas mass control flow meter.

[0202] The heat exchange device is a shell-and-tube heat exchanger.

[0203] The regenerative combustion system operates at normal temperature and pressure according to the control method shown in the accompanying Figure 2 The VOCs exhaust gas source has a concentration of 500-12000 mg / m 3 , and the concentration of the exhaust gas treated by the pretreatment system is 3000-6000 mg / m 3 . The overall system has been continuously and stably operated for more than one week without any abnormality, and the exhaust gas discharged by the regenerative combustion device meets the environmental protection requirements.

[0204] Example 3

[0205] A regenerative combustion system for a fluctuating VOCs exhaust gas source, the devices used are shown in the accompanyingFigure 1

[0206] The adsorbing material in the first pretreatment device is water, the dynamic adsorption capacity of which in reversible adsorption and desorption is 35mg / g, the liquid-gas ratio during operation is 3L / m 3 , the empty tower gas speed is 1.5m / s, the residence time is 2.5s, the adsorbing material in the second pretreatment device is activated carbon fiber, the dynamic adsorption capacity of which in reversible adsorption and desorption is 357mg / g, the residence time of waste gas during operation is 2s, and the gas flow rate is 1m / s.

[0207] The heat accumulation combustion device is a three-chamber RTO.

[0208] The first, second and third gas detection modules are FID and mass flow controllers, which can detect gas concentration and flow rate.

[0209] The mass flow controller is a thermal gas mass control flow meter.

[0210] The heat exchange device is a plate heat exchanger.

[0211] The heat accumulation combustion system is controlled according to the control method shown in the figure. Figure 2 The VOCs waste gas source has a waste gas concentration fluctuating in the range of 50-100000mg / m 3 , the concentration of the waste gas treated by the pretreatment system is 3000-6000mg / m 3 , the overall system continuously and stably operates for more than one week without any abnormal situation, and the exhaust gas of the heat accumulation combustion device meets the environmental protection requirements.

[0212] Although the present application has been disclosed with reference to the preferred embodiments, it is not intended to limit the present application. Those skilled in the art can make various modifications and improvements without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application is defined by the claims.

[0213] In addition, it should be understood that although the present application is described in the specification, each embodiment only contains one independent technical solution, and the description manner of the specification is only for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined to form other embodiments which can be understood by those skilled in the art. The technical details not described in detail in the present application can be realized by any existing technology in the art. In particular, all the technical features not described in detail in the present application can be realized by any existing technology.​

Claims

1. A regenerative combustion system for a fluctuating VOCs exhaust source, characterized in that, The heat accumulation combustion system comprises an air inlet pipeline, a pretreatment system, a heat accumulation combustion device and a control system, the inlet end of the pretreatment system is connected to the outlet end of the air inlet pipeline, and the outlet end of the pretreatment system is connected to the inlet end of the heat accumulation combustion device; The pretreatment system comprises multiple parallelly arranged pretreatment paths, the pretreatment paths comprise a first pretreatment path, a second pretreatment path and a third pretreatment path; The control system comprises a gas detection module, the gas detection module is arranged at least at the inlet end and the outlet end of the pretreatment system, and is used for detecting the waste gas parameters entering the pretreatment system; The air inlet pipeline outputs waste gas into the pretreatment system, the control system obtains waste gas parameters through the gas detection module, and according to the change of the waste gas parameters, corresponding pretreatment paths are enabled to process the waste gas concentration to a target range, and then the waste gas is input into the heat accumulation combustion device, so as to realize the control of the heat accumulation combustion system.

2. The regenerative combustion system for fluctuating VOCs waste gas source of claim 1, wherein, The first pretreatment path comprises a first pipeline; The first pipeline is connected between the outlet end of the air inlet pipeline and the inlet end of the heat accumulation combustion device, and the first pretreatment path is used for directly inputting the waste gas into the heat accumulation combustion device.

3. The regenerative combustion system for fluctuating VOCs waste gas source of claim 1, wherein, The second pretreatment path comprises a second pipeline, a first pretreatment device and a third pipeline; The second pipeline is connected between the outlet end of the air inlet pipeline and the input end of the first pretreatment device, the third pipeline is connected between the output end of the first pretreatment device and the inlet end of the heat accumulation combustion device, and the second pretreatment path is used for adsorbing or desorbing the waste gas through the first pretreatment device and then inputting the waste gas into the heat accumulation combustion device. The third pretreatment path comprises a fourth pipeline, a second pretreatment device and a fifth pipeline; 4. The regenerative combustion system for fluctuating VOCs waste gas source of claim 3, wherein, The fourth pipeline is connected between the output end of the first pretreatment device and the input end of the second pretreatment device, the fifth pipeline is connected between the output end of the second pretreatment device and the inlet end of the heat accumulation combustion device, and the third pretreatment path is used for adsorbing or desorbing the waste gas through the second pretreatment device after the waste gas passes through the first pretreatment device and then inputting the waste gas into the heat accumulation combustion device. The pretreatment system further comprises a fourth pretreatment path, the fourth pretreatment path comprises a sixth pipeline, a heat exchange device, a seventh pipeline and an eighth pipeline; The sixth pipeline is connected between the outlet end of the heat accumulation combustion device and the input end of the heat exchange device, the seventh pipeline is connected between the output end of the heat exchange device and the input end of the second pretreatment device, the eighth pipeline is connected between the output end of the second pretreatment device and the inlet end of the heat accumulation combustion device, and the fourth pretreatment path is used for desorbing the waste gas adsorbed by the second pretreatment device after the second pretreatment device adsorbs the waste gas from the heat accumulation combustion device and then inputting the waste gas into the heat accumulation combustion device.

5. The regenerative combustion system for fluctuating VOCs waste gas source of claim 4, wherein, ​ ​ ​ 6. A regenerative combustion system for a fluctuating VOCs waste gas source according to claim 3 or 4, wherein, The first pretreatment device is provided with a heating device.

7. A control method for a regenerative combustion system for fluctuating VOCs exhaust sources as claimed in any one of claims 1-6, characterized in that, The control method comprises the following steps: S1, the exhaust gas enters the pretreatment system from the intake pipeline, and the control system acquires the intake concentration C2 and the exhaust concentration C1 of the pretreatment system; S2, the control system controls the pretreatment system according to C2 and C1: When C S1 ≤ C2 < C S2 , the first preprocessing path is opened, and further when C S1 ≤ C1 < C S2 , S3 is executed. When C S2 ≤ C2 < C S3 , the second preprocessing path is opened, and further when C S1 ≤ C1 < C S2 , S3 is executed. When C S2 ≤ C2 < C S3 , the second preprocessing path and the third preprocessing path are opened, and then when C S1 ≤ C1 < C S2 , S3 is executed. When C2 < C S1 , the second preprocessing path is opened, and further when C S1 ≤ C1 < C S2 , S3 is executed. When C2 < C S1 , the second pre-processing path and the third pre-processing path are enabled, and then when C S1 ≤ C1 < C S2 , S3 is executed. when C2 < C S1 , the second pre-processing path is opened, and the first pre-processing device heating device is turned on, and then when C S1 ≤ C1 < C S2 , S3 is executed; When C2 < C S1 , the second and fourth preprocessing paths are opened, and the first preprocessing device heating device and heat exchange device are opened, and then when C S1 ≤ C1 < C S2 , S3 is executed. S3, the exhaust gas enters the regenerative combustion device; C S1 <C S2 <C S3 ; The C S1 is a first set value for the exhaust gas concentration; the C S2 is a second set value for the exhaust gas concentration; the C S3 is a third set value for the exhaust gas concentration.

8. The control method of a regenerative combustion system for fluctuating VOCs exhaust sources according to claim 7, characterized in that, In the step S2: When C S2 ≤ C2 < C S3 , the second preprocessing path is first opened, and then when C S2 ≤ C1 < C S3 , the third preprocessing path is opened, and finally when C S1 ≤ C1 < C S2 , S3 is executed. When C2 < C S1 , the second preprocessing path is first opened, and then when C1 < C S1 , the third preprocessing path is opened, and finally when C S1 ≤ C1 < C S2 , S3 is executed. When C2 < C S1 , the second pre-processing path and the third pre-processing path are first opened, then when C1 < C S1 , the third pre-processing path is closed and the first pre-processing device heating device is opened, and finally when C S1 ≤ C1 < C S2 , S3 is executed. When C2 < Cs1, the second pre-processing path is first opened, and the first pre-processing device heating device is opened, and then when C1 < Cs1, the fourth pre-processing path is further opened, and the heat exchange device is opened, and finally when Cs1≤C1<C s2 , S3 is executed.

9. A control method for a regenerative combustion system for a fluctuating VOCs waste gas source according to claim 7 or 8, characterized in that, In the 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 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 / 4q, C S1 = Cmin, 1.2Cmin≤ C S2 ≤ 2.0Cmin, C S3 = 1 / 4LEL; 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; Wherein Cmin is the minimum concentration for maintaining the self-heating combustion of the regenerative combustion device, LEL is the minimum explosion limit value of the exhaust gas, and qt is the real-time VOCs adsorption amount of the pretreatment system; Wherein t is the operation time of the pretreatment system, Q1 is the exhaust air volume of the pretreatment system, Q2 is the intake 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 a fluctuating VOCs waste gas source according to any one of claims 7-9, characterized in that, In the step S2: The heating temperature of the first pre-treatment device heating device is T3, ΔC1=C S1 C1, and the control system automatically controls T3 according to ΔC1: When ΔC1≤0, the heating device of the first pretreatment device is not started; 0 < ΔC1≤ 500 mg / m 3 T3 = 40 °C when 500 mg / m 3 <AC1≤ 1000 mg / m 3 T3 = 60 °C 1000 mg / m 3 <AC1≤ 2000 mg / m 3 T3 = 80 °C The heat exchange device processes the gas to a temperature T4, and the second pretreatment path has an outlet gas concentration C3, ΔC2 = C S1 -C3, The control system automatically controls T4 according to ΔC2: When ΔC2<0, the heat exchange device is not started; 0 < ΔC2< 500 mg / m 3 T4 - 40 °C; 500 mg / m 3 <△C2≤ 1000 mg / m 3 T4 - 60 °C; 1000 mg / m 3 <△C2 < 2000 mg / m 3 T4 - 80 °C; 2000 mg / m 3 <△C2<3000 mg / m 3 T4 - 100 °C; 3000 mg / m 3 <△C2 <4000 mg / m 3 T4 = 120°C.

Images