A zero-emission vehicle system and method for achieving nitrogen recovery and reuse of VOCs.

Abstract

This invention relates to the field of hazardous gas storage and transportation and environmental protection technology, and particularly to a VOCs zero-emission loading system and method for achieving nitrogen recovery and reuse. The system includes a tank truck, a nitrogen recovery unit, a buffer tank, a nitrogen reuse unit, and a detection and control unit. The tank truck has a rigid tank body with a fluororubber liner inside, forming a sealed interlayer space. The nitrogen recovery unit consists of a nitrogen recovery pipeline, a filter, and a pneumatic control valve. The nitrogen reuse unit consists of a nitrogen reuse pipeline and a pressure regulating valve. The detection and control unit includes a VOCs detector, an oxygen content detector, and a control system. By optimizing the tank truck structure, standardizing the liner fixing method, using an external exhaust valve and a self-sealing quick connector, and adding a pressure-stabilizing reuse circuit, the entire loading process is achieved with a sealed system, efficient nitrogen circulation, and safe operation.

Description

Technical Field

[0001] This invention relates to the field of hazardous gas storage and transportation and environmental protection technology, and in particular to a zero-emission VOCs loading system and method for realizing nitrogen recovery and reuse. Background Technology

[0002] In industries such as coking and fine chemicals, loading high-temperature, volatile organic materials is a critical step in production, storage, and transportation. These materials are highly volatile, and the traditional open loading method generates a large amount of unorganized emissions of VOCs (volatile organic compounds, including alkanes, aromatics, esters, alcohols, ketones, halogenated hydrocarbons, and olefins). This not only causes raw material loss and pollutes the atmospheric environment but also endangers the health of on-site workers. In addition, the accumulation of VOCs can easily lead to safety accidents such as fires and explosions.

[0003] To control VOCs emissions, the industry is gradually promoting nitrogen-sealed loading technology, which uses nitrogen to create an inert, slightly positive pressure environment to suppress VOCs volatilization. However, existing nitrogen-sealed loading technology has several unresolved problems: First, some loading systems directly return VOCs-containing recovered tail gas to negative pressure gas pipelines, which can easily trigger frequent activation of gas pipeline shut-off valves, leading to production interruptions and affecting operational continuity. Second, if the recovered nitrogen needs to be reused, additional pressurization equipment is required, increasing equipment investment, energy consumption, and maintenance costs. Third, nitrogen reuse lacks pressure stabilization and control measures, making it unable to meet the slightly positive pressure requirements of low-pressure gas-using equipment such as electrostatic precipitators, resulting in poor gas supply stability. Fourth, the tank truck exhaust structure design is unreasonable, with the exhaust valve built-in, requiring personnel to enter the tank for operation, posing a risk of nitrogen asphyxiation and VOCs poisoning. Fifth, the tank truck's inner liner fixing structure is not standardized, making it prone to displacement and wrinkles, affecting loading and nitrogen recovery efficiency. Summary of the Invention

[0004] This invention overcomes the problems existing in the prior art and provides a VOCs zero-emission loading system and method for realizing nitrogen recovery and reuse. By optimizing the tank truck structure, standardizing the inner liner fixing method, adopting an external exhaust valve and a self-sealing quick connector, and adding a pressure stabilizing and reuse circuit, the entire loading process is sealed, nitrogen circulation is highly efficient, and operation is safe.

[0005] To achieve the above objectives, the present invention employs the following technical solution: A zero-emission VOCs loading system for nitrogen recovery and reuse includes a tank truck, a nitrogen recovery unit, a buffer tank, a nitrogen reuse unit, and a detection and control unit. The tank truck has a rigid tank body with a fluororubber liner inside, forming a sealed interlayer space between the rigid tank body and the fluororubber liner. An exhaust pipe extends from the top of the fluororubber liner through the top of the rigid tank body, with a top exhaust valve at the exit end. The rigid tank body has an interlayer filling port and an interlayer exhaust port. The nitrogen recovery unit consists of a nitrogen recovery pipeline and a filter and pneumatic control valve installed on the nitrogen recovery pipeline. The buffer tank has a pressure indicator and a safety pressure relief device at the top and a bottom... A drain valve is provided; the nitrogen reuse unit consists of a nitrogen reuse pipeline and a pressure regulating valve installed on the nitrogen utilization pipeline; the jacketed outlet of the rigid tank is connected to a buffer tank through a nitrogen recovery pipeline, and the buffer tank is connected to a low-pressure gas consumption point through a nitrogen reuse pipeline; the detection and control unit includes a VOCs detector, an oxygen content detector, and a control system. The VOCs detector and oxygen content detector are installed on the nitrogen recovery pipeline. The detection signal output terminals of the VOCs detector and oxygen content detector are connected to the control system. The control signal output terminal of the control system is connected to the control terminal of the pressure indicator, safety pressure relief device, pneumatic control valve, pressure regulating valve, and tank truck loading pump.

[0006] The thickness of the fluororubber liner is 10-15 mm.

[0007] The outer side of the fluororubber inner liner is provided with 3 to 6 flexible pull straps. The multiple flexible pull straps are evenly arranged in the transverse direction along the fluororubber inner liner. The two ends of each flexible pull strap are connected to the inner wall of the left end cap and the inner wall of the right end cap of the rigid tank, respectively. The outer wall of the fluororubber inner liner is provided with multiple reinforcing lifting rings for the flexible pull straps to pass through.

[0008] The interlayer inflation port is connected to the nitrogen input pipeline via an inflation quick connector; the interlayer gas outlet is connected to the nitrogen recovery pipeline via a recovery quick connector; both the inflation quick connector and the recovery quick connector are self-sealing quick connectors.

[0009] The low-pressure gas supply point includes an electrostatic precipitator insulation box.

[0010] The VOCs detector has a detection range of 0~1000ppm, and the oxygen content detector has a detection range of 0~25%; the control system adopts a PLC controller and integrates an audible and visual alarm module.

[0011] A method for zero-emission vehicle installation of VOCs to achieve nitrogen recovery and reuse includes the following steps: (1) Install the fluororubber inner liner into the rigid tank and fix each flexible strap; open the top exhaust valve outside the tank truck and fill the interlayer space with nitrogen through the quick-connect fitting to exhaust the air inside the interlayer space; when the oxygen content in the gas discharged from the interlayer space is detected to meet the standard, close the top exhaust valve and continue to fill the interlayer space with nitrogen until the pressure reaches the set value to complete the gas replacement in the interlayer space. (2) After the tanker enters the loading station, the gas outlet of the interlayer is connected to the nitrogen recovery pipeline through the quick-connect coupling; the control system starts the VOCs detector and oxygen content detector to detect the VOCs concentration and oxygen content in the nitrogen recovery pipeline. When the VOCs concentration and oxygen content in the nitrogen recovery pipeline meet the standards, the loading conditions are met. (3) Start the tanker loading pump, the material enters the fluororubber inner liner and expands it, squeezing the nitrogen in the interlayer space. The nitrogen enters the buffer tank through the nitrogen recovery pipeline. The pressure indicator transmits the pressure signal to the control system in real time. The control system interlocks and adjusts the opening of the pressure regulating valve. The nitrogen in the buffer tank is delivered to the low-pressure gas point through the nitrogen reuse pipeline. (4) After loading is completed, close the tank truck loading pump and pneumatic control valve, disconnect the inflation quick connector and the recovery quick connector, and the loaded tank truck drives away; (5) Repeat steps (2) to (4) when loading the tank trucks.

[0012] In step (1), when the oxygen content in the gas discharged from the interlayer space is detected to be ≤1.8%, the top exhaust valve is closed, and nitrogen is continued to be filled into the interlayer space until the pressure reaches 0.07~0.09MPa, thus completing the gas replacement in the interlayer space.

[0013] In step (2), the conditions for loading are met when the VOCs concentration in the nitrogen recovery pipeline is ≤30ppm and the oxygen content is ≤1.8%.

[0014] In step (3), the nitrogen in the buffer tank is delivered to the low-pressure gas point through the nitrogen reuse pipeline at a stable pressure of 0.04 to 0.06 MPa.

[0015] Compared with the prior art, the beneficial effects of the present invention are: (1) Balancing environmental protection and production: The entire loading process is carried out in a closed manner, with zero VOCs emissions. At the same time, it avoids the return of VOCs to the gas pipeline, completely solving the problem of frequent start-up of the shut-off valve interlock, thus balancing environmental protection requirements and production continuity.

[0016] (2) High-efficiency and energy-saving reuse of nitrogen: Recovered nitrogen relies on its own residual pressure for stable transportation, eliminating the need for pressurization equipment, reducing energy consumption and equipment investment, significantly reducing the consumption of fresh nitrogen, and saving production costs.

[0017] (3) The system operates safely and stably: self-sealing joints are used to achieve leak-free disassembly and assembly, external exhaust valves are used to achieve contactless operation, flexible pull straps are used to fix the inner liner in a standardized manner, and pressure interlocking is used to stabilize the pressure and eliminate the risk of pressure buildup. Multiple safety guarantees improve the reliability of system operation.

[0018] (4) Practical structure and easy operation and maintenance: The tank truck adopts an inner and outer double-layer structure, which can avoid material corrosion of the rigid tank. The fluororubber inner liner is easy to disassemble and assemble. The system has no complex power equipment, low failure rate, low operation and maintenance cost, and is suitable for loading high temperature and volatile materials. It is especially suitable for the closed loading of high temperature and volatile organic materials. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a zero-emission VOCs vehicle loading system for nitrogen recovery and reuse as described in this invention.

[0020] In the diagram: 1-Tank truck; 11-Rigid tank body; 112-Interlayer air inlet; 113-Interlayer air outlet; 114-Inflation quick connector; 115-Recovery quick connector; 12-Fluororubber inner liner; 121-Flexible strap; 122-Top exhaust valve; 13-Interlayer space; 2-Nitrogen recovery pipeline; 22-Filter; 23-Pneumatic control valve; 3-Buffer tank; 31-Pressure indicator; 32-Safety pressure relief device; 33-Drain valve; 4-Nitrogen reuse pipeline; 41-Pressure regulating valve; 5-Detection and control unit; 51-VOCs detector; 52-Oxygen content detector; 53-Control box. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: like Figure 1As shown, the present invention discloses a VOCs zero-emission loading system for nitrogen recovery and reuse, comprising a tank truck 1, a nitrogen recovery unit, a buffer tank 3, a nitrogen reuse unit, and a detection and control unit 5. The tank truck 1 is equipped with a rigid tank body 11, inside which is a fluororubber liner 12, forming a sealed interlayer space 13. An exhaust pipe is provided at the top of the fluororubber liner 12, extending from the top of the rigid tank body 11, and a top exhaust valve 122 is provided at the outlet end. The rigid tank body 11 is provided with an interlayer filling port 112 and an interlayer exhaust port 113. The nitrogen recovery unit consists of a nitrogen recovery pipeline 2, a filter 22 installed on the nitrogen recovery pipeline 2, and a pneumatic control valve 23. The buffer tank 3 is equipped with a pressure indicator 31 and a safety pressure relief device at its top. The device 32 has a drain valve 33 at the bottom; the nitrogen reuse unit consists of a nitrogen reuse pipeline 4 and a pressure regulating valve 41 located on the nitrogen utilization pipeline; the interlayer outlet 113 of the rigid tank 11 is connected to the buffer tank 3 through the nitrogen recovery pipeline 2, and the buffer tank 3 is connected to the low-pressure gas point through the nitrogen reuse pipeline 4; the detection and control unit 5 includes a VOCs detector 51, an oxygen content detector 52 and a control system, the VOCs detector 51 and the oxygen content detector 52 are installed on the nitrogen recovery pipeline 2, the detection signal output terminals of the VOCs detector 51 and the oxygen content detector 52 are connected to the control system, and the control signal output terminal of the control system is connected to the pressure indicator 31, the safety pressure relief device 32, the pneumatic control valve 23, the pressure regulating valve 41 and the control terminal of the tank truck loading pump.

[0022] The thickness of the fluororubber inner liner 12 is 10-15 mm.

[0023] The outer side of the fluororubber inner liner 12 is provided with 3 to 6 flexible pull straps 121. The multiple flexible pull straps 121 are evenly arranged in the transverse direction of the fluororubber inner liner 12. The two ends of each flexible pull strap 121 are connected to the inner wall of the left end cap and the inner wall of the right end cap of the rigid tank body 11, respectively. Multiple reinforcing lifting rings are provided on the outer wall of the fluororubber inner liner 12 for the flexible pull straps 121 to pass through.

[0024] The interlayer air inlet 112 is connected to the nitrogen input pipeline via an air inlet quick connector 114; the interlayer air outlet 113 is connected to the nitrogen recovery pipeline 2 via a recovery quick connector 115; both the air inlet quick connector 114 and the recovery quick connector 115 are self-sealing quick connectors.

[0025] The low-pressure gas supply point includes an electrostatic precipitator insulation box.

[0026] The VOCs detector 51 has a detection range of 0 to 1000 ppm, and the oxygen content detector 52 has a detection range of 0 to 25%. The control system adopts a PLC controller and integrates an audible and visual alarm module.

[0027] A method for zero-emission vehicle installation of VOCs to achieve nitrogen recovery and reuse includes the following steps: (1) Insert the fluororubber inner liner 12 into the rigid tank body 11 and fix each flexible pull strap 121; open the top exhaust valve 122 outside the tank truck 1, and fill the interlayer space 13 with nitrogen through the quick-connect gas filling connector 114 to exhaust the air inside the interlayer space 13; when the oxygen content in the gas discharged from the interlayer space 13 is detected to meet the standard, close the top exhaust valve 122 and continue to fill the interlayer space 13 with nitrogen until the pressure reaches the set value, thus completing the gas replacement in the interlayer space 13; (2) After the tanker truck 1 enters the loading station, the interlayer gas outlet 113 is connected to the nitrogen recovery pipeline 2 through the quick-connect coupling 115; the control system starts the VOCs detector 51 and the oxygen content detector 52 to detect. When the VOCs concentration and oxygen content in the nitrogen recovery pipeline 2 meet the standards, the loading conditions are met. (3) Start the tanker loading pump, the material enters the fluororubber inner liner 12 and expands it, squeezing the nitrogen in the interlayer space 13. The nitrogen enters the buffer tank 3 through the nitrogen recovery pipeline 2. The pressure indicator device 31 transmits the pressure signal to the control system in real time. The control system interlocks and adjusts the opening of the pressure regulating valve 41. The nitrogen in the buffer tank 3 is delivered to the low-pressure gas point through the nitrogen reuse pipeline 4. (4) After loading is completed, close the tanker loading pump and pneumatic control valve 23, disconnect the inflation quick connector 114 and the recovery quick connector 115, and the loaded tanker 1 drives away; (5) Repeat steps (2) to (4) when loading the tank trucks.

[0028] Furthermore, in step (1), when the oxygen content in the gas discharged from the interlayer space is detected to be ≤1.8%, the top exhaust valve 122 is closed, and nitrogen is continued to be filled into the interlayer space 13 until the pressure reaches 0.07~0.09MPa, thus completing the gas replacement in the interlayer space 13.

[0029] Furthermore, in step (2), the vehicle loading conditions are met when the VOCs concentration in the nitrogen recovery pipeline 2 is ≤30ppm and the oxygen content is ≤1.8%.

[0030] Furthermore, in step (3), the nitrogen in the buffer tank 3 is delivered to the low-pressure gas point through the nitrogen reuse pipeline 4 at a stable pressure of 0.04 to 0.06 MPa.

[0031] The VOCs zero-emission loading system for nitrogen recovery and reuse described in this invention consists of five parts: a tank truck 1, a nitrogen recovery unit, a buffer tank 3, a nitrogen reuse unit, and a detection and control unit 5. The specific structure and connection relationship of each part are as follows: 1. Tank truck The container on tanker truck 1 that carries materials is a horizontal, rigid tank 11 with a double-layer composite structure of a fluororubber inner liner 12. The rigid tank 11 is preferably a pressure tank made of Q235 steel to ensure overall structural strength. The fluororubber inner liner 12 contains the materials, forming a sealed interlayer space 13 between the fluororubber inner liner 12 and the rigid tank 11 for filling with nitrogen gas for sealing. The side walls of the rigid tank 11 are respectively provided with an interlayer filling port 112 and an interlayer outlet 113, and are respectively equipped with a quick-connect fitting 114 for filling and a quick-connect fitting 115 for recovery. Both quick-connect fittings are self-sealing quick-connect fittings commonly used in the chemical industry. When connected, the valve core opens to form a passage; after disassembly, the valve core automatically springs back to close, ensuring no gas leakage throughout the process, preventing VOCs from escaping and avoiding nitrogen waste.

[0032] The thickness of the fluororubber inner liner 12 is preferably 10-15mm. It is made of fluororubber material that is resistant to high temperature, oil, and swelling, and is suitable for loading high-temperature volatile organic materials.

[0033] Three to six flexible pull straps 121 are evenly distributed on the outer side of the fluororubber inner liner 12 (evenly arranged in the transverse direction). The two ends of the flexible pull straps 121 are fixedly connected to the inner walls of the left and right end caps of the rigid tank body 11, respectively (lifting lugs can be welded to the inner walls of the left and right end caps, and the flexible pull straps 121 are fixed by bolts after passing around the lifting lugs). The flexible pull straps 121 pass through multiple reinforcing lifting rings set on the outer wall of the fluororubber inner liner 12, thereby effectively restraining the displacement of the fluororubber inner liner 12 during the expansion process, avoiding the fluororubber inner liner 12 from deviating, wrinkling, or getting stuck, ensuring its uniform expansion, and ensuring smooth nitrogen recovery. The fluororubber inner liner 12 is equipped with an exhaust pipe at the top. The exhaust pipe passes through the interlayer space 13 and the top of the rigid tank 11 and extends to the outside of the rigid tank 11. The extended end is equipped with a top exhaust valve 122 (preferably a manual ball valve). Operators do not need to enter the rigid tank 11 and can complete the exhaust and valve closing operations from outside the tank truck 1, completely avoiding the safety risks of personnel entering the tank for operation.

[0034] 2. Nitrogen recovery unit, buffer tank and nitrogen reuse unit The nitrogen recovery pipeline 2 is made of seamless steel pipe. One end of it is connected to the interlayer outlet 113 on the top of the rigid tank 11 via a quick-connect coupling 115, and the other end is connected to the air inlet on the upper side of the buffer tank 3. The nitrogen recovery pipeline 2 is equipped with a filter 22 and a pneumatic control valve 23. The filter 22 is used to filter impurities such as oil mist and dust in the recovered nitrogen to prevent impurities from clogging the pipeline and damaging the gas-using equipment. The pneumatic control valve 23 is used to control the on / off state of the nitrogen recovery pipeline 2.

[0035] The buffer tank 3 is a vertical, sealed tank made of carbon steel, used for temporary storage and recovery of nitrogen. A pressure indicator 31 and a safety relief device 32 are installed on the top of the tank to monitor the internal pressure in real time and automatically relieve pressure in case of overpressure, ensuring safe operation of the tank. A drain valve 33 is installed at the bottom of the tank to periodically drain the condensate and impurities deposited inside. The outlet on one side of the lower part of the buffer tank 3 is connected to the nitrogen reuse pipeline 4.

[0036] A pressure regulating valve 41 is installed on the nitrogen reuse pipeline 4. The pressure regulating valve 41 and the pressure indicating device 31 are interlocked and controlled by the control system. That is, the control system automatically adjusts the opening of the pressure regulating valve 41 according to the pressure inside the tank, and delivers the recovered nitrogen to the low-pressure gas consumption point (such as providing nitrogen protection gas for the electrostatic precipitator insulation box) under stable pressure. No additional pressurization equipment is required. The residual pressure of the buffer tank 3 itself can meet the low-pressure gas consumption needs (such as the pressure regulating valve 41 stabilizing the output pressure at a slight positive pressure of 0.04~0.06MPa to match the gas consumption needs of the electrostatic precipitator insulation box). At the same time, it realizes simultaneous recovery and output, and completely eliminates the risk of system pressure buildup.

[0037] 3. Detection and Control Unit The detection and control unit 5 consists of a VOCs detector 51, an oxygen content detector 52, and a control system (installed in the control box 53). The VOCs detector 51 is installed upstream of the nitrogen recovery pipeline 2 to accurately detect the VOCs concentration and oxygen content in the interlayer gas. The control system is connected to the VOCs detector 51, the oxygen content detector 52, the pneumatic control valve 23, the pressure regulating valve 41, and the tank truck loading pump to realize pre-loading detection and automated control during the loading process. Loading can only start if the detection indicators meet the standards; if they exceed the standards, an audible and visual alarm will be triggered and the loading process will be stopped, thus ensuring the safety of the loading operation at the source.

[0038] The working principle of the VOCs zero-emission vehicle loading system for nitrogen recovery and reuse described in this invention is as follows: The system adopts an integrated working method of "closed loading + nitrogen recovery + pressure stabilization and reuse + safety management". First, the gas replacement of the inner space and the nitrogen sealing of the fluororubber inner liner 12 are completed through the top exhaust valve 122, eliminating the risk of personnel entering the tank for operation. During loading, the material squeezes the fluororubber inner liner 12, and the nitrogen in the interlayer space 13 enters the buffer tank 3 through the recovery quick connector 115 and the nitrogen recovery pipeline 2, avoiding the return of VOCs tail gas to the gas pipeline. The nitrogen in the buffer tank 3 is controlled by the pressure indicator device 31 and the pressure regulating valve 41 to stabilize and deliver it to the low-pressure gas consumption point, realizing the on-site reuse of nitrogen without power, which not only eliminates the risk of pressure buildup, but also improves the nitrogen utilization rate. The entire operation process is safely managed by the detection and control unit 5 to ensure zero VOCs emissions and stable operation of the system throughout the loading process.

[0039] This invention is designed for the loading process, while the unloading operation is completed in a separate factory area, and its work process is the reverse of the loading process.

[0040] To more intuitively illustrate the present invention, the embodiments of the present invention will be further described in conjunction with the examples. The following examples are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention, including simple variations or equivalent substitutions, are all within the scope of protection of the present invention.

[0041]

Example

[0042] The rigid tank 11 on tanker truck 1 is a horizontal steel tank with a volume of 20m³. 3 The pressure resistance rating is 0.15MPa. The fluororubber inner liner 12 is 12mm thick and has a temperature resistance range of -20℃ to 120℃, making it suitable for loading coal tar at around 90℃.

[0043] The height of the interlayer space 13 is 50mm. The side wall of the rigid tank 11 is provided with a DN50 interlayer air inlet 112 and an interlayer air outlet 113, and self-sealing air inlet quick connector 114 and self-sealing recycle quick connector 115 are installed respectively.

[0044] Four flexible pull straps 121 are arranged on the outside of the fluororubber inner liner 12. The two ends of the flexible pull straps 121 are fixed to the inner wall of the left end cap and the inner wall of the right end cap of the rigid tank body 11, respectively. An exhaust pipe is provided at the top of the fluororubber inner liner 12, which extends out of the top surface of the rigid tank body 11 and is connected to a DN25 top exhaust valve 122 (manual ball valve).

[0045] In this embodiment, the nitrogen recovery pipeline 2 uses a DN50 seamless steel pipe, on which a filter 22 (80-mesh Y-type filter) and a pneumatic control valve 23 are installed. The buffer tank 3 has a volume of 3m³, a pressure resistance of 0.15MPa, a pressure indicator 31 with a range of 0-0.2MPa, and a pressure relief device 32 with a pressure relief setting of 0.1MPa. The nitrogen reuse pipeline 4 uses a DN40 seamless steel pipe, and the pressure regulating valve 41 is a pneumatic regulating valve with a stable output pressure of 0.05MPa.

[0046] In this embodiment, the VOCs detector 51 in the detection and control unit 5 has a detection range of 0 to 1000 ppm, the oxygen content detector 52 has a detection range of 0 to 25%, and the control system adopts a PLC controller with an integrated audible and visual alarm module.

[0047] The loading process in this embodiment is as follows: (1) Insert the fluororubber inner liner 12 into the rigid tank body 11 and fix each flexible pull strap 121; open the top exhaust valve 122 outside the tank truck 1 and fill the interlayer space 13 with nitrogen through the quick-connect gas filling connector 114 to exhaust the air inside the interlayer space 13; when the oxygen content in the gas discharged from the interlayer space 13 is detected to be ≤2%, close the top exhaust valve 122 and continue to fill the interlayer space 13 with nitrogen until the pressure reaches 0.08MPa to complete the gas replacement in the interlayer space 13; (2) After the tanker truck 1 enters the loading station, the interlayer gas outlet 113 is connected to the nitrogen recovery pipeline 2 through the quick-connect coupling 115; the control system starts the VOCs detector 51 and the oxygen content detector 52 to detect the VOCs concentration in the nitrogen recovery pipeline 2 to 30ppm and the oxygen content to 1.8% when the loading conditions are met. (3) Start the tanker loading pump, the material enters the fluororubber inner liner 12 and expands it, squeezing the nitrogen in the interlayer space 13. The nitrogen enters the buffer tank 3 through the nitrogen recovery pipeline 2. The pressure indicator device 31 transmits the pressure signal to the control system in real time. The control system interlocks and adjusts the opening of the pressure regulating valve 41. The nitrogen in the buffer tank 3 is delivered to the low-pressure gas point through the nitrogen reuse pipeline 4 at a stable pressure of 0.05MPa. (4) After loading is completed, close the tanker loading pump and pneumatic control valve 23, disconnect the inflation quick connector 114 and the recovery quick connector 115, and the loaded tanker 1 drives away; (5) Repeat steps (2) to (4) when loading the tank trucks.

[0048] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A zero-emission VOCs vehicle loading system for nitrogen recovery and reuse, characterized in that, The system includes a tank truck, a nitrogen recovery unit, a buffer tank, a nitrogen reuse unit, and a detection and control unit. The tank truck has a rigid tank body with a fluororubber liner inside, forming a sealed interlayer space between the rigid tank body and the fluororubber liner. An exhaust pipe extends from the top of the fluororubber liner through the top of the rigid tank body, with a top exhaust valve at the exit end. The rigid tank body has an interlayer filling port and an interlayer exhaust port. The nitrogen recovery unit consists of a nitrogen recovery pipeline and filters and pneumatic control valves installed on the pipeline. The buffer tank has a pressure indicator and a safety pressure relief device at the top and a drain valve at the bottom. The nitrogen reuse unit... The unit consists of a nitrogen reuse pipeline and a pressure regulating valve installed on the nitrogen utilization pipeline; the jacketed outlet of the rigid tank is connected to a buffer tank through a nitrogen recovery pipeline, and the buffer tank is connected to a low-pressure gas consumption point through a nitrogen reuse pipeline; the detection and control unit includes a VOCs detector, an oxygen content detector, and a control system. The VOCs detector and oxygen content detector are installed on the nitrogen recovery pipeline. The detection signal output terminals of the VOCs detector and oxygen content detector are connected to the control system. The control signal output terminal of the control system is connected to the control terminal of the pressure indicator, safety pressure relief device, pneumatic control valve, pressure regulating valve, and tank truck loading pump.

2. The VOCs zero-emission vehicle loading system for nitrogen recovery and reuse according to claim 1, characterized in that, The thickness of the fluororubber liner is 10-15 mm.

3. The VOCs zero-emission vehicle loading system for nitrogen recovery and reuse according to claim 1, characterized in that, The outer side of the fluororubber inner liner is provided with 3 to 6 flexible pull straps. The multiple flexible pull straps are evenly arranged in the transverse direction along the fluororubber inner liner. The two ends of each flexible pull strap are connected to the inner wall of the left end cap and the inner wall of the right end cap of the rigid tank, respectively. The outer wall of the fluororubber inner liner is provided with multiple reinforcing lifting rings for the flexible pull straps to pass through.

4. The VOCs zero-emission vehicle loading system for nitrogen recovery and reuse according to claim 1, characterized in that, The interlayer inflation port is connected to the nitrogen input pipeline via an inflation quick connector; the interlayer gas outlet is connected to the nitrogen recovery pipeline via a recovery quick connector; both the inflation quick connector and the recovery quick connector are self-sealing quick connectors.

5. A zero-emission VOCs vehicle loading system for nitrogen recovery and reuse according to claim 1, characterized in that, The low-pressure gas supply point includes an electrostatic precipitator insulation box.

6. A VOCs zero-emission vehicle loading system for nitrogen recovery and reuse according to claim 1, characterized in that, The VOCs detector has a detection range of 0~1000ppm, and the oxygen content detector has a detection range of 0~25%; the control system adopts a PLC controller and integrates an audible and visual alarm module.

7. A method for zero-emission VOCs installation in vehicles to achieve nitrogen recovery and reuse, characterized in that, This is achieved based on the VOCs zero-emission vehicle installation system for nitrogen recovery and reuse as described in any one of claims 1 to 6; characterized by comprising the following steps: (1) Install the fluororubber inner liner into the rigid tank and fix each flexible strap; open the top exhaust valve outside the tank truck and fill the interlayer space with nitrogen through the quick-connect fitting to exhaust the air inside the interlayer space; when the oxygen content in the gas discharged from the interlayer space is detected to meet the standard, close the top exhaust valve and continue to fill the interlayer space with nitrogen until the pressure reaches the set value to complete the gas replacement in the interlayer space. (2) After the tanker enters the loading station, the gas outlet of the interlayer is connected to the nitrogen recovery pipeline through the quick-connect coupling; the control system starts the VOCs detector and oxygen content detector to detect the VOCs concentration and oxygen content in the nitrogen recovery pipeline. When the VOCs concentration and oxygen content in the nitrogen recovery pipeline meet the standards, the loading conditions are met. (3) Start the tanker loading pump, the material enters the fluororubber inner liner and expands it, squeezing the nitrogen in the interlayer space. The nitrogen enters the buffer tank through the nitrogen recovery pipeline. The pressure indicator transmits the pressure signal to the control system in real time. The control system interlocks and adjusts the opening of the pressure regulating valve. The nitrogen in the buffer tank is delivered to the low-pressure gas point through the nitrogen reuse pipeline. (4) After loading is completed, close the tank truck loading pump and pneumatic control valve, disconnect the inflation quick connector and the recovery quick connector, and the loaded tank truck drives away; (5) Repeat steps (2) to (4) when loading the tank trucks.

8. The method for zero-emission VOCs vehicle installation to achieve nitrogen recovery and reuse according to claim 7, characterized in that, In step (1), when the oxygen content in the gas discharged from the interlayer space is detected to be ≤1.8%, the top exhaust valve is closed, and nitrogen is continued to be filled into the interlayer space until the pressure reaches 0.07~0.09MPa, thus completing the gas replacement in the interlayer space.

9. The method for zero-emission VOCs vehicle installation to achieve nitrogen recovery and reuse according to claim 7, characterized in that, In step (2), the conditions for loading are met when the VOCs concentration in the nitrogen recovery pipeline is ≤30ppm and the oxygen content is ≤1.8%.

10. The method for zero-emission VOCs vehicle installation to achieve nitrogen recovery and reuse according to claim 7, characterized in that, In step (3), the nitrogen in the buffer tank is delivered to the low-pressure gas point through the nitrogen reuse pipeline at a stable pressure of 0.04 to 0.06 MPa.

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