Multistage heat pump coupling microwave desorption system

Abstract

The invention relates to the technical field of industrial VOCs treatment, in particular to a multistage heat pump coupling microwave desorption system which comprises a microwave targeted preheating module, a heat pump gradient heating module, a low-pressure desorption environment construction module and a waste heat recovery network. The heating device is used for selectively heating a VOCs enrichment area; the heat pump gradient heating module adopts a multi-stage heat pump system, the adsorbent is heated to 130-160 DEG C from 70 DEG C in a gradient manner, and the heating rate is 8 DEG C / min; the low-pressure desorption environment construction module is used for designing a negative pressure pipeline based on the Venturi effect to form a-1.5 kPa desorption environment; and the waste heat recovery network comprises a plate heat exchanger and a heat pump evaporator and is used for realizing efficient recovery of desorption waste gas waste heat. The gradient activation composite zeolite rotating wheel and the AI dynamic regulation and control platform are matched, real-time optimization of microwave power, heat pump output and negative pressure parameters is achieved, and the device is suitable for treatment of high-concentration VOCs in the industries of coating, rubber, printing and the like.

Description

Technical Field

[0001] This invention relates to the field of industrial VOCs treatment technology, and in particular to a multi-stage heat pump coupled microwave desorption system. Background Technology

[0002] Currently, traditional thermal desorption technologies (such as RTO and CO) are widely used in the field of industrial VOCs (volatile organic compounds) treatment, but they have significant drawbacks: 1. High energy consumption: Traditional thermal desorption requires heating the adsorbent, with a unit energy consumption of 0.8-1.2 kWh / kg VOCs, and the flue gas temperature of RTO system is as high as 300-400℃, with a waste heat utilization rate of only 35%-45%; 2. Slow heating: Relying on external heat conduction, the heating rate is usually less than 3℃ / min, resulting in a long desorption cycle; 3. Low desorption efficiency: Under normal pressure, the desorption air volume needs to reach 1 / 5 to 1 / 3 of the adsorption air volume, and the fan energy consumption accounts for 20% to 30% of the total system energy consumption.

[0003] While microwave desorption technology can achieve selective heating, its application as a standalone method suffers from uneven energy distribution and large fluctuations in desorption temperature. Although heat pump technology can achieve heat recovery, a single heat pump system is insufficient to meet the requirements for gradient heating over a wide temperature range.

[0004] To address the above problems, this invention proposes a multi-stage heat pump coupled microwave desorption system. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-stage heat pump coupled microwave desorption system, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A multi-stage heat pump coupled microwave desorption system includes a microwave targeted preheating module, a heat pump gradient heating module, a low-pressure desorption environment construction module, and a waste heat recovery network. Microwave-targeted preheating module: Equipped with a 2.45GHz microwave generator and an infrared thermal imaging scanner, it is used to selectively heat the VOCs-enriched area, raising the adsorbent temperature to 70°C. Heat pump gradient heating module: A multi-stage heat pump system is used to gradually heat the adsorbent from 70℃ to 130-160℃ at a heating rate of 8℃ / min. Low-pressure desorption environment construction module: Based on the Venturi effect, a negative pressure pipeline is designed to form a desorption environment of -1.5 kPa, with a desorption wind speed of 0.8-1.2 m / s; Waste heat recovery network: including plate heat exchangers and heat pump evaporators, it realizes efficient recovery of waste heat from desorbed exhaust gas, with a waste heat utilization rate of ≥72%.

[0007] Preferably, the microwave targeted preheating module includes a magnetron assembly with a power density of 0.8-1.2 W / cm³, and can be controlled in zones.

[0008] Preferably, the infrared thermal imaging scanner has a temperature recognition accuracy of ±5℃ and a spatial resolution of ±5mm, and is used to identify VOCs enrichment areas on the adsorbent.

[0009] Preferably, the temperature control accuracy of the heat pump gradient heating module is ±2℃, and the heat pump energy efficiency ratio (COP) is ≥3.5.

[0010] Preferably, the desorption air volume of the low-pressure desorption environment construction module is reduced by 30% compared with the traditional process, and the desorption energy consumption is reduced by 45%.

[0011] Preferably, in the waste heat recovery network, 50% of the waste heat is used for system self-heating, and 22% of the waste heat is used for workshop heating.

[0012] Preferably, it further includes a pretreatment unit, which includes a condensation dehumidification module and an electrostatic dust removal module; the dew point of the condensation dehumidification module is ≤5℃, and the humidity of the treated exhaust gas is <30% RH; the electrostatic dust removal module has a filtration efficiency of >95% for particles with a diameter >1μm.

[0013] Preferably, a gradient-activated composite zeolite rotor is used in conjunction with the rotor. The desorption zone of the rotor adopts a titanium-silicon molecular sieve TS-1 layer with a pore size of 5-8 nm, and its surface is pressed with sinusoidal ripples, which increases the specific surface area by 22%.

[0014] Preferably, the desorbed waste gas is treated by a gas-liquid separator with a separation efficiency of >99%, and the condensate is collected and then enters the wastewater treatment system.

[0015] Preferably, an integrated AI dynamic control platform is used, which is based on a VOCs concentration prediction model and adjusts microwave power, heat pump output and negative pressure parameters 15 minutes in advance to achieve real-time optimization of operating parameters.

[0016] Compared with the prior art, the multi-stage heat pump coupled microwave desorption system of the present invention has the following beneficial effects: 1. Significantly improved energy efficiency: Microwave targeted heating rapidly raises the temperature of the VOCs-rich area to 70°C, and combined with heat pump gradient heating to 160°C, desorption energy consumption is reduced by 45%, saving 0.36-0.54 kWh / kg VOCs compared to traditional processes; The five-stage waste heat utilization network (300℃→200℃→150℃→80℃→50℃) increases the waste heat utilization rate from 35% to 72%, with 50% of the waste heat used for the system's self-heating.

[0017] 2. Desorption efficiency optimization: The Venturi effect creates a low-pressure desorption environment of -1.5 kPa, reducing the desorption air volume by 30% and controlling the desorption air velocity at 0.8-1.2 m / s to avoid excessive disturbance of the adsorbent. The heating time is reduced by 67%, from 45-60 minutes in the traditional process to within 15 minutes.

[0018] 3. Intelligence and stability: The AI ​​dynamic control platform optimizes parameters 15 minutes in advance based on a VOCs concentration prediction model, improving system stability by 20% and extending equipment life by 15%. Attached Figure Description

[0019] Figure 1 This is a flowchart of a multi-stage heat pump coupled microwave desorption system according to the present invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] like Figure 1 As shown, a multi-stage heat pump coupled microwave desorption system includes a microwave targeted preheating module, a heat pump gradient heating module, a low-pressure desorption environment construction module, and a waste heat recovery network. Microwave-targeted preheating module: Equipped with a 2.45GHz microwave generator and an infrared thermal imaging scanner, it is used to selectively heat the VOCs-enriched areas, raising the adsorbent temperature to 70℃; the microwave-targeted preheating module includes a magnetron assembly with a power density of 0.8-1.2W / cm³, and can be controlled in zones; the infrared thermal imaging scanner has a temperature recognition accuracy of ±5℃ and a spatial resolution of ±5mm, used to identify VOCs-enriched areas on the adsorbent; Heat pump gradient heating module: It adopts a multi-stage heat pump system to gradually heat the adsorbent from 70℃ to 130-160℃, with a heating rate of 8℃ / min; the temperature control accuracy of the heat pump gradient heating module is ±2℃, and the heat pump energy efficiency ratio COP≥3.5; Low-pressure desorption environment construction module: Based on the Venturi effect, a negative pressure pipeline is designed to form a desorption environment of -1.5 kPa, with a desorption air velocity of 0.8-1.2 m / s. The desorption air volume of the low-pressure desorption environment construction module is reduced by 30% compared with the traditional process, and the desorption energy consumption is reduced by 45%. Waste heat recovery network: including plate heat exchangers and heat pump evaporators, it realizes efficient recovery of waste heat from desorbed exhaust gas, with a waste heat utilization rate of ≥72%; in the waste heat recovery network, 50% of the waste heat is used for system self-heating and 22% of the waste heat is used for workshop heating. It also includes a pretreatment unit, which comprises a condensation dehumidification module and an electrostatic dust removal module; the dew point of the condensation dehumidification module is ≤5℃, and the humidity of the treated exhaust gas is <30% RH; the electrostatic dust removal module has a filtration efficiency of >95% for particles with a diameter >1μm; a gradient-activated composite zeolite rotor is used in conjunction, the desorption zone of which adopts a titanium-silicon molecular sieve TS-1 layer with a pore size of 5-8nm, and its surface is pressed with sinusoidal ripples, increasing the specific surface area by 22%; the desorbed exhaust gas is treated by a gas-liquid separator with a separation efficiency >99%, and the condensate is collected and enters the wastewater treatment system; an integrated AI dynamic control platform is used, which is based on a VOCs concentration prediction model and adjusts the microwave power, heat pump output, and negative pressure parameters 15 minutes in advance to achieve real-time optimization of operating parameters.

[0022] Example 1: VOCs Treatment Project at a Pharmaceutical Factory 1. System Configuration: Treatment capacity: 20,000 m³ / h of waste gas, initial VOCs concentration of 800-1200 mg / m³ (ethyl acetate accounts for 65%, acetone accounts for 25%, and the remainder is benzene series compounds); Core equipment: Gradient-activated composite zeolite rotor (3m in diameter, 0.4m in height, with 20% of the TS-1 molecular sieve desorption zone). Microwave-heat pump desorption unit (2.45GHz magnetron assembly × 12 units, three-stage compression heat pump system); RTO incinerator (5000 m³ / h capacity, 95% thermal efficiency) and catalytic combustion chamber (precious metal catalyst, ignition temperature 280℃).

[0023] 2. Operating parameters:

[0024] 3. Measured data: A. Energy efficiency indicators: Unit desorption energy consumption: 0.44 kWh / kg VOCs (0.8 kWh / kg VOCs for traditional RTO systems); Waste heat recovery rate: 72% (of which 50% is used for system self-heating and 22% is used for workshop heating); Overall system COP: 3.6 (COP of traditional single-stage heat pump system ≈ 2.8).

[0025] B. Processing efficiency: Total VOCs removal rate: 99.2% (outlet concentration < 10 mg / m³); Rotary adsorption efficiency: 95% (ethyl acetate), 92% (acetone), 98% (benzene series compounds); Desorption rate: 98.5% (average), with the TS-1 molecular sieve zone achieving a desorption rate of 99.5%.

[0026] C. Operational stability: AI regulation reduces system fluctuations to less than 5% (compared to traditional system fluctuations of more than 15%). The adsorbent lifespan is extended to 5 years (compared to 3 years in traditional processes). Equipment maintenance cycle: 6 months (3 months for traditional processes).

[0027] D. Economic Analysis: Annual operating costs: Electricity cost: 1.8 million yuan (3 million yuan for traditional system). Adsorbent replacement cost: 400,000 yuan / year (600,000 yuan / year for traditional systems). Investment payback period: 2.8 years (total equipment investment of RMB 3.36 million).

[0028] Example 2: A lithium battery anode material production line 1. System Configuration: Treatment capacity: 15,000 m³ / h of waste gas volume, initial VOCs concentration of 600-900 mg / m³ (NMP accounting for 90%). Core equipment: Composite molecular sieve rotor (diameter 2.5m, height 0.35m, fully covered by TS-1 molecular sieve). Microwave-heat pump desorption unit (10 x 2.45GHz magnetrons, two-stage compression heat pump system); Condensation recovery unit (-15℃ cryogenic system, recovery efficiency 95%).

[0029] 2. Operating parameters:

[0030] 3. Measured data: A. Energy efficiency indicators: Unit desorption energy consumption: 0.38 kWh / kgNMP (conventional steam desorption is 1.2 kWh / kgNMP); NMP recovery rate: 95% (condensate purity 98.5%). Waste heat recovery rate: 75% (of which 55% is used for system self-heating and 20% is used for raw material preheating).

[0031] B. Processing efficiency: Total VOCs removal rate: 99.5% (outlet concentration < 5 mg / m³); Rotary adsorption efficiency: 98% (NMP); Desorption rate: 99.2% (NMP).

[0032] C. Operational stability: AI-driven regulation kept system fluctuations below 3%. The moisture content in the condensate is <0.5% (meets the reuse requirements); The equipment operated continuously for 300 days without any faults.

[0033] D. Economic Analysis: Annual operating costs: Electricity cost: 1.2 million yuan (3.6 million yuan for traditional system). NMP recycling revenue: 2.4 million yuan / year (calculated based on recycling 480 tons of NMP / year at a unit price of 5,000 yuan / ton); Investment payback period: 1.9 years (total equipment investment of RMB 2.8 million).

[0034] Comparative experimental data

[0035] Key technology verification Verification of the synergistic effect of microwave-heat pump: Experimental conditions: Simulated waste gas (ethyl acetate concentration 1000 mg / m³), adsorbent was honeycomb activated carbon; Test results: Microwave alone: ​​desorption rate of 65% at 70℃, local overheating leads to ablation of the adsorbent; Heat pump alone: ​​78% desorption rate at 110℃, heating time 25 minutes; Microwave-heat pump coupling: 98% desorption rate from 70 to 130℃, heating time 8 minutes, no local overheating.

[0036] Low-pressure environment enhanced desorption verification: Experimental conditions: Simulated waste gas (toluene concentration 800 mg / m³), adsorbent was TS-1 molecular sieve; Test results: Atmospheric pressure desorption (0 kPa): 92% desorption rate at 110℃, desorption time 15 minutes; Negative pressure desorption (-1.5kPa): 99% desorption rate at 110℃, 8 minutes desorption time, and 30% reduction in desorption air volume.

[0037] AI dynamic control effect verification: Experimental conditions: Actual pharmaceutical waste gas, VOCs concentration fluctuating between 500-1500 mg / m³; Test results: Without AI control: system response time > 30 minutes, energy consumption fluctuation ±15%; With AI regulation: system response time < 5 minutes, energy consumption fluctuation ± 3%, prediction accuracy > 95%.

[0038] The above data shows that the present invention, through the synergistic effect of microwave-heat pump-negative pressure, is significantly superior to traditional technologies in terms of energy efficiency, treatment efficiency and operational stability, and is especially suitable for the treatment of heat-sensitive, high-concentration VOCs.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A multi-stage heat pump coupled microwave desorption system, comprising a microwave targeted preheating module, a heat pump gradient heating module, a low-pressure desorption environment construction module, and a waste heat recovery network, characterized in that: The microwave targeted preheating module: a 2.45 GHz microwave generator and an infrared thermal imaging scanner are configured to selectively heat the VOCs-rich area, raising the adsorbent temperature to 70℃. The heat pump gradient heating module: a multi-stage heat pump system is used to raise the adsorbent temperature from 70℃ to 130-160℃ at a rate of 8℃ / min. The low-pressure desorption environment construction module: a negative pressure pipeline is designed based on the Venturi effect to form a desorption environment of -1.5 kPa, with a desorption air speed of 0.8-1.2 m / s. The waste heat recovery network: contains a plate heat exchanger and a heat pump evaporator to achieve efficient recovery of desorption waste gas waste heat.

2. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: The microwave targeted preheating module includes a magnetron group with a power density of 0.8-1.2 W / cm³ and can be controlled in zones.

3. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: The infrared thermal imaging scanner has a temperature identification accuracy of ±5℃ and a spatial resolution of ±5 mm, and is used to identify the VOCs-rich area on the adsorbent.

4. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: The heat pump gradient heating module has a temperature control accuracy of ±2℃ and a heat pump energy efficiency ratio COP≥3.

5.

5. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: In the waste heat recovery network, 50% of the waste heat is used for system self-heating, and 22% of the waste heat is used for workshop heating.

6. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: It also includes a pretreatment unit, which includes a condensation and dehumidification module and an electrostatic dust removal module; the dew point of the condensation and dehumidification module is ≤5℃, and the humidity of the treated exhaust gas is <30% RH; the electrostatic dust removal module has a filtration efficiency of >95% for particles with a particle size of >1 μm.

7. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: A gradient activated composite zeolite runner is used in conjunction, the desorption area of the runner uses a titanium-silicon molecular sieve TS-1 layer with a pore size of 5-8 nm, and the surface is pressed with a sinusoidal wave.

8. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: The desorption exhaust gas is treated by a gas-liquid separator, which has a separation efficiency of >99%, and the condensed liquid is collected and then enters the wastewater treatment system.

9. The multi-stage heat pump coupled microwave desorption system of claim 1, wherein: An AI dynamic regulation platform is integrated, which is based on a VOCs concentration prediction model and adjusts the microwave power, heat pump output, and negative pressure parameters 15 minutes in advance to realize real-time optimization of operating parameters.

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