Aerosol sampling and measuring system suitable for steam flowing system and control method of aerosol sampling and measuring system

Abstract

The invention relates to the technical field of aerosol measurement, in particular to an aerosol sampling and measuring system suitable for a steam flowing system and a control method thereof, and the aerosol sampling and measuring system comprises a primary sampling structure, a secondary sampling structure, a gas filling structure, a full development structure, a discharge structure, a measurement and control host and an aerosol measuring host; the sampling end of the first-stage sampling structure is arranged in a target measurement environment, the gas filling structure is arranged at the downstream of the first-stage sampling structure, a heating sleeve is arranged on the outer side of the gas filling structure, the peripheral wall of the gas filling structure is communicated with an exhaust pipe and a gas injection pipe, and convection is formed between a gas inlet, communicated with the first-stage sampling structure, of the gas filling structure and a gas outlet of the gas injection pipe; the full development structure is arranged at the downstream of the gas filling structure, and the sampling end of the secondary sampling structure is arranged in the full development structure; the discharge structure is disposed downstream of the adequate development structure. According to the invention, a steam condensation phenomenon in a gas mixing process can be effectively avoided, and aerosol constant-speed sampling in a high gas flow rate change range is realized.

Description

Technical Field

[0001] This invention relates to the field of aerosol measurement technology, and more specifically, to an aerosol sampling and measurement system and its control method suitable for vapor flow systems. Background Technology

[0002] A severe reactor accident is accompanied by a core meltdown, which releases a large amount of radioactive material and water vapor. Some of the radioactive material will appear in the form of aerosols. This further leads to the formation of a high-temperature, high-pressure steam flow environment containing radioactive aerosols in the primary or secondary loop pipes at different stages of the accident. Considering the strong diffusion and adsorption properties of aerosols, in order to reasonably assess the migration and release of radioactive material, it is necessary to conduct experiments to accurately predict the aerosol deposition behavior in this environment. This involves the corresponding aerosol concentration measurement requirements.

[0003] Currently, commonly used measurement devices include online measurement equipment such as optical particle size spectrometers and multi-stage impactors, as well as offline measurement methods such as membrane filtration and weighing, solution washing and absorption combined with chemical detection. However, existing offline measurement methods cannot obtain aerosol particle size distribution data. Due to the lack of precise flow control, all measurement methods are unsuitable for pure steam environments. The condensation of steam during sampling makes it difficult for offline measurement methods to accurately control the steam flow rate, and most online measurement devices are not suitable for pure steam environments. Furthermore, the fixed sampling flow rate requirements of various devices are often not applicable to the isokinetic sampling principle for aerosols in flowing environments, especially in high-flow-rate environments, where the sampling flow rate conforming to the isokinetic sampling principle is often much higher than the rated flow rate of the measurement equipment. Summary of the Invention

[0004] The purpose of this invention is to provide an aerosol sampling and measurement system and its control method suitable for vapor flow systems. Through a convective air filling structure, the partial pressure and temperature of vapor in the gas space can be reduced in stages, while avoiding vapor condensation and reducing aerosol diffusion loss. The control logic based on multiple physical parameters such as pressure, temperature and flow rate can ensure the automatic operation of the system under the target operating conditions, and realize the isokinetic sampling function of aerosols under high gas flow rate variation range, so as to solve the technical problems pointed out in the background art.

[0005] This invention is achieved through the following technical solution: an aerosol sampling and measurement system suitable for vapor flow systems, comprising a primary sampling structure, a gas filling structure, a fully developed structure, an emission structure, a secondary sampling structure, a measurement and control host, and an aerosol measurement host; The sampling end of the primary sampling structure is arranged in the target measurement environment. The gas filling structure is arranged downstream of the primary sampling structure. A heating jacket is provided on its outer side, and an exhaust pipe and an injection pipe are connected to its outer peripheral wall. The gas filling structure is connected to the air inlet of the primary sampling structure to form convection between the air outlet of the injection pipe and the air inlet of the primary sampling structure. The heating jacket is electrically connected to a DC power supply. The fully developed structure is arranged downstream of the gas filling structure, the sampling end of the secondary sampling structure is arranged in the fully developed structure, a measurement probe is provided downstream of the secondary sampling structure, and the measurement probe is communicatively connected to the aerosol measurement host. The emission structure is located downstream of the fully developed structure. The exhaust pipe, the air injection pipe, and the emission structure are all equipped with flow meters, pressure sensing devices, temperature sensing devices, and flow regulating valves. The flow meters, pressure sensing devices, and temperature sensing devices are all communicatively connected to the signal input terminal of the monitoring and control host. The signal output terminal of the monitoring and control host is communicatively connected to the flow regulating valve.

[0006] According to a preferred embodiment, the sampling ends of both the primary sampling structure and the secondary sampling structure are L-shaped.

[0007] According to a preferred embodiment, a condensate tank and a steam-water separator are sequentially provided downstream of the secondary sampling structure.

[0008] According to a preferred embodiment, the gas filling structure includes an outer cylinder, the outer cylinder having a central flow channel and a multi-stage stepped flow channel distributed in a ring outside the central flow channel, the exhaust pipe and the gas injection pipe being connected to the multi-stage stepped flow channel, the multi-stage stepped flow channel being connected to the central flow channel, the first end of the central flow channel being connected to a primary sampling structure, and the second end of the central flow channel being connected to a fully developed structure.

[0009] According to a preferred embodiment, the inner diameter of the first end of the central flow channel is smaller than the inner diameter of its second end, the inner diameter of the outlet of the primary sampling structure is smaller than the inner diameter of the first end of the central flow channel, and the inner diameter of the inlet of the fully developed structure is equal to the inner diameter of the second end of the central flow channel.

[0010] According to a preferred embodiment, the outer cylinder is provided with a plurality of inner cylinders with different outer diameters. The plurality of inner cylinders are arranged in a stepped manner, forming a multi-level stepped flow channel together with the inner wall of the outer cylinder. The inner cylinder with a larger outer diameter is arranged near the second end of the central flow channel, and the inner cylinder with a smaller outer diameter is arranged near the first end of the central flow channel. The air injection pipe is arranged on the outside of the inner cylinder with a larger outer diameter, and the exhaust pipe is arranged on the outside of the inner cylinder with a smaller outer diameter. According to a preferred embodiment, a gas guiding ring rib is sleeved on the outer side of the first end of the inner cylinder. A plurality of flow guiding holes are opened on both the gas guiding ring rib and the second end of the inner cylinder. The flow guiding holes have oblique openings to form oblique flow channels that intersect with the multi-stage stepped flow channels and connect to the central flow channel. The oblique flow channels are located between adjacent inner cylinders.

[0011] According to a preferred embodiment, a flow distribution ring rib is sleeved on the outer side of the inner cylinder, and a plurality of evenly distributed flow distribution holes are formed on the flow distribution ring rib.

[0012] The present invention also provides a control method for an aerosol sampling and measurement system suitable for a vapor flow system as described above, comprising the following steps: Under the premise that the pressure, flow rate and temperature of the gas inside the gas filling structure and the fully developed structure meet the experimental requirements, open the ball valve on the secondary sampling structure. Obtain the gas flow rate Q1 of the injection pipe, the gas flow rate Q2 of the exhaust pipe, and the gas flow rate Q4 of the first-stage sampling structure, and calculate the mixed gas ratio of the fully developed structure. Calculate the density of the mixed gas based on the proportion and temperature of the mixed gas in a fully developed structure; The flow rate of the downstream gas in the secondary sampling structure is adjusted based on the density of the mixed gas to meet the density requirements of the particle size analyzer. The actual aerosol particle size distribution is calculated based on the dilution ratio and the original aerosol particle size distribution. The dilution ratio is determined based on the flow rate adjustment of the gas downstream of the secondary sampling structure.

[0013] According to a preferred embodiment, the steps for constructing a scenario that meets the experimental requirements are as follows: Step 1: Obtain the pressure data P0 inside the target measurement environment, the pressure data P1 inside the air injection pipe, the pressure data P2 inside the exhaust pipe, and the pressure data P3 inside the fully developed structure. Determine whether each pressure data meets the first preset condition. If so, proceed to Step 2. The first preset condition is P1 > P1 > P0 > P3 > 10 kPa. If not, generate a first control command, which is used to instruct the opening of the flow regulating valves on the air injection pipe, exhaust pipe and discharge structure to be adjusted sequentially; Step 2: Obtain the gas flow rate Q1 of the injection pipe, the gas flow rate Q2 of the exhaust pipe, and the mixed gas flow rate Q3 of the fully developed structure. Based on Q1, Q2, Q3, P0 and the gas temperature T0 inside the target measurement environment, calculate the gas flow rate Q4 of the primary sampling structure. Convert the gas velocity V2 of the primary sampling structure according to Q4 and determine whether V2 meets the second preset condition. If so, proceed to step 3. The second preset condition is that the difference between V2 and the gas velocity V1 inside the target measurement environment is less than a preset threshold. Otherwise, a second control command is generated, which is used to instruct the opening degree of the flow regulating valve on the discharge structure; Step 3: Obtain the gas temperature T1 of the injection pipe, the gas temperature T2 of the exhaust pipe, and the temperature T3 of the mixed gas with a fully developed structure. Determine whether each temperature data meets the third preset condition. If so, proceed to step 4. The third preset condition is that both T1 and T2 meet the system operation requirements and T3 is within the preset temperature range. If not, a third control command is generated, which is used to instruct the adjustment of the heating power of the heating jacket, and to sequentially adjust the opening of the flow regulating valves on the air injection pipe and the air exhaust pipe when the heating power exceeds the limit.

[0014] The technical solution of the aerosol sampling and measurement system and its control method suitable for steam flow systems provided by this invention has at least the following advantages and beneficial effects: (1) Through the convection air filling structure, the staged heating method of air can effectively avoid the phenomenon of steam condensation during the gas mixing process. The design of the radial gas filling structure can apply a force away from the wall to the aerosol. While solving the problem of aerosol concentration measurement in pure steam environment, it can also reduce the wall loss of aerosol during the sampling process and improve the accuracy of the measurement results. (2) By adding an air filling process, real-time gas flow control can be implemented, thereby enabling the measurement of aerosol concentration in a steam environment; (3) The control logic based on multiple physical parameters such as pressure, temperature and flow rate can ensure the automatic operation of the system under the target working conditions and realize the function of isokinetic sampling of aerosols under high gas flow rate variation range. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the aerosol sampling and measurement system suitable for steam flow systems provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the gas filling structure provided in Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the structure of the multi-stage inner cylinder provided in Embodiment 2 of the present invention; Figure 4This is a schematic diagram of the flow distribution ring rib provided in Embodiment 2 of the present invention; Figure 5 This is a flowchart illustrating the control method provided in Embodiment 3 of the present invention; Reference numerals: 1-Temperature sensing device, 2-Pressure sensing device, 3-Vortex flow meter, 4-Flow regulating valve, 5-Ball valve, 6-First-stage sampling structure, 7-Gas filling structure, 8-DC power supply, 9-Injection pipe, 10-Exhaust pipe, 11-Fully developed structure, 12-Discharge structure, 13-Second-stage sampling mechanism, 14-Measuring probe, 15-Condensate tank, 16-Gas-water separator filter, 17-Drain valve, 18-Flow controller, 19-Aerosol measurement host, 20-Measurement and control host, 21-Connecting flange, 22-Sealing structure, 23-Rib support structure, 24-Flow distribution rib, 25-Gas guide rib, 26-Flow guide hole, 27-Flow distribution hole, 28-Inner cylinder. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Example 1 This embodiment provides an aerosol sampling and measurement system suitable for vapor flow systems. Figure 1 This is a schematic diagram of the aerosol sampling and measurement system suitable for vapor flow systems. (See attached diagram) Figure 1 As shown, the aerosol sampling and measurement system suitable for vapor flow systems includes a primary sampling structure 6, a gas filling structure 7, a fully developed structure 11, an emission structure 12, a secondary sampling structure, a measurement and control host 20, and an aerosol measurement host 19.

[0018] The sampling end of the primary sampling structure 6 is arranged in the target measurement environment. In this embodiment, the sampling end of the primary sampling structure 6 adopts an L-shaped design to ensure that the incoming aerosol can flow evenly through this L-shaped sampling end and enter the gas filling structure 7.

[0019] The gas filling structure 7 is arranged downstream of the primary sampling structure 6 to reduce the temperature, velocity, and pressure of the sampling gas, thereby providing a stable mixed gas ratio for the secondary sampling structure. Furthermore, a heating jacket is provided on the outer side of the gas filling structure 7, and its outer peripheral wall is connected to an exhaust pipe 10 and an injection pipe 9. The gas filling structure 7 connects to the air inlet of the primary sampling structure 6 and the air outlet of the injection pipe 9 to form convection. Furthermore, the heating jacket is electrically connected to a DC power supply 8. In a preferred embodiment of this invention, the temperature of the internal gas is controlled by directly heating the outer side of the gas filling structure 7 with a heating jacket, thereby reducing the pressure and temperature of the mixed gas inside the filling structure while avoiding steam condensation.

[0020] In some specific embodiments of this example, the gas filling structure 7 includes an outer cylinder, which contains a central flow channel and a multi-stage stepped flow channel arranged in a ring around the outside of the central flow channel. The exhaust pipe 10 and the gas injection pipe 9 are both connected to the multi-stage stepped flow channel. The multi-stage stepped flow channel is connected to the central flow channel. The first end of the central flow channel is connected to the first-stage sampling structure 6, and the second end of the central flow channel is connected to the fully developed structure 11.

[0021] It should be noted that when the outer cylinder is heated by the heating jacket, the temperature of the gas injected into the gas injection pipe 9 is increased stepwise as it flows through the multi-stage stepped flow channel. This causes the sampling gas entering the central flow channel of the fully developed structure 11 through the first-stage sampling structure 6 to be intermittently replenished with air of gradually decreasing temperature. As a result, the gas pressure and temperature of the sampling gas in the central flow channel of the gas filling structure 7 are effectively reduced. While the vapor partial pressure decreases, the condensation temperature also gradually decreases, thus effectively preventing vapor condensation.

[0022] Specifically, the staged heating and injection of air through the convection air filling structure can effectively avoid the phenomenon of steam condensation during the gas mixing process. Furthermore, the design of the radial gas filling structure 7 can apply a force to the aerosol away from the wall surface. This solves the problem of aerosol concentration measurement in a pure steam environment, while reducing wall loss of aerosols during the sampling process and improving the accuracy of the measurement results. The fully developed structure 11 is arranged downstream of the gas filling structure 7 to create a mixed gas environment and deliver sample gas for aerosol sampling of the secondary sampling structure. In some embodiments of this example, the outer cylinder is provided with connecting flanges 21 at both ends, and the outlet end of the primary sampling structure 6 and the inlet end of the fully developed structure 11 are provided with connecting flanges 21 corresponding to the outer cylinder, and the three are connected in sequence through the connecting flanges 21; furthermore, a sealing structure 22 is provided on the outside of the connecting flange 21 to complete the sealing installation.

[0023] The sampling end of the secondary sampling structure is arranged in the fully developed structure 11 to perform secondary sampling of the mixed gas in the mixed gas environment. In this embodiment, the sampling end of the secondary sampling structure also adopts an L-shaped design to ensure that the mixed gas can flow uniformly through this L-shaped sampling end and enter the downstream for measurement. A measurement probe 14 is provided downstream of the secondary sampling structure to obtain aerosol particle size distribution information. The measurement probe 14 is communicatively connected to the aerosol measurement host 19 and sends the obtained aerosol particle size distribution information to the aerosol measurement host 19. In some embodiments, a condensate tank 15, a gas-liquid separator filter 16, and a flow controller 18 are also sequentially provided downstream of the secondary sampling structure. The flow controller 18 is used to regulate the flow rate of the gas downstream of the secondary sampling structure to meet the density requirements of the particle size analyzer. The flow controller 18 is communicatively connected to the measurement and control host 20. In addition, a drain valve 17 is provided at the outlet of the gas-liquid separator filter 16.

[0024] The emission structure 12 is arranged downstream of the fully developed structure 11. The exhaust pipe 10, the injection pipe 9, and the emission structure 12 are all equipped with a flow meter, a pressure sensing device 2, a temperature sensing device 1, and a flow regulating valve 4. The flow meter is used to collect the gas flow rate of the corresponding area, the pressure sensing device 2 is used to collect the gas pressure data of the corresponding area, and the temperature sensing device 1 is used to collect the gas temperature of the corresponding area. The flow meter, pressure sensing device 2, and temperature sensing device 1 are all communicatively connected to the signal input terminal of the monitoring and control host 20 to send the collected data to the monitoring and control host 20. The signal output terminal of the monitoring and control host 20 is communicatively connected to the flow regulating valve 4 to perform self-feedback adjustment of the flow regulating valve 4 in each area based on the received data, thereby achieving the functions of unified cooling, pressure reduction, speed reduction, and isokinetic sampling.

[0025] Specifically, this embodiment achieves the measurement of aerosol concentration in a steam environment by adding an air filling process and performing real-time gas flow control. In addition, the control logic based on multiple physical parameters such as pressure, temperature and flow rate can ensure the automatic operation of the system under the target working conditions and realize the isokinetic sampling function of aerosols under high gas flow rate variation range.

[0026] Example 2 This embodiment further explains the gas filling structure 7 based on the technical solution provided in Embodiment 1: In this embodiment, the first end of the central flow channel is designed as a narrow channel with an inner diameter smaller than that of the second end. The outlet inner diameter of the primary sampling structure 6 is smaller than that of the first end of the central flow channel to reduce aerosol loss on the wall surface. The inlet inner diameter of the fully developed structure 11 is equal to that of the second end of the central flow channel to create a stable flow environment for the mixed gas and deliver stable sample gas for aerosol sampling of the secondary sampling structure.

[0027] See Figure 2 As shown, the outer cylinder contains several inner cylinders with different outer diameters, which are arranged in a stepped manner to form a multi-level stepped flow channel together with the inner wall of the outer cylinder. The inner cylinder with the larger outer diameter is arranged near the second end of the central flow channel, and the inner cylinder with the smaller outer diameter is arranged near the first end of the central flow channel. The air injection pipe 9 is arranged on the outside of the inner cylinder with the larger outer diameter to form convection with the air inlet of the central flow channel. The exhaust pipe 10 is arranged on the outside of the inner cylinder with the smaller outer diameter. The exhaust pipe 10 is arranged on the same side as the air injection pipe 9 or distributed on different sides of the outer cylinder. No specific limitation is made here.

[0028] In some preferred embodiments, the inner cylinder is made of a cylindrical ceramic plate, with a gas guide ring rib 25 sleeved on the outer side of its first end. Both the gas guide ring rib 25 and the second end of the inner cylinder are provided with a plurality of flow guide holes 26 to control the flow of gas injected by the gas injection pipe 9 into the central flow channel. The flow guide holes 26 have oblique openings to form oblique flow channels that intersect with the multi-stage stepped flow channels and connect to the central flow channel. The oblique flow channels are located between adjacent inner cylinders. While controlling the flow of gas injected by the gas injection pipe 9 into the central flow channel, the gas is injected into the central flow channel in an oblique direction to reduce aerosol loss caused by airflow collision.

[0029] Further, see Figure 3 As shown, a flow distribution ring rib 24 is fitted onto the outer side of the inner cylinder. The flow distribution ring rib 24 has several evenly distributed flow distribution holes 27 to achieve gas flow equalization. The outer sides of both the gas guiding ring rib 25 and the flow distribution ring rib 24 are abutted against the inner wall of the outer cylinder through a ring rib support structure 23. See also... Figure 4 As shown, the flow distribution hole 27 on the flow distribution ring 24 can ensure that the gas flows evenly, and at the same time control the gas flow rate of the gas guide ring 25 corresponding to each stage of the inner cylinder and the pressure difference before and after the gas guide ring 25. Together with the flow distribution hole 27, it controls the gas flow rate of each stage of the multi-stage stepped flow channel entering the central flow channel. When the heating jacket heats the air inside the multi-stage stepped flow channel, air with a gradually decreasing temperature is intermittently supplied to the central flow channel.

[0030] Example 3 This embodiment is based on the control method for an aerosol sampling and measurement system suitable for vapor flow systems provided in any one of Embodiments 1 to 2. See [link to Embodiment 1]. Figure 5 As shown, it includes the following steps: Under the premise that the pressure, flow rate and temperature of the gas inside the gas filling structure 7 and the fully developed structure 11 meet the experimental requirements, open the ball valve 5 on the secondary sampling structure. Obtain the gas flow rate Q1 of the gas injection pipe 9, the gas flow rate Q2 of the gas discharge pipe 10, and the gas flow rate Q4 of the first-stage sampling structure 6, and calculate the mixed gas ratio of the fully developed structure 11. Calculate the gas density based on the gas mixture ratio and gas mixture temperature of the fully developed structure 11; The flow rate of the downstream gas in the secondary sampling structure is adjusted based on the density of the mixed gas to meet the density requirements of the particle size analyzer. The actual aerosol particle size distribution is calculated based on the dilution ratio and the original aerosol particle size distribution. The dilution ratio is determined based on the flow rate adjustment of the gas downstream of the secondary sampling structure.

[0031] In some implementations of this embodiment, the steps for building a scenario that meets the experimental requirements are as follows: Step 1: Obtain the pressure data P0 inside the target measurement environment, the pressure data P1 inside the air injection pipe 9, the pressure data P2 inside the exhaust pipe 10, and the pressure data P3 inside the fully developed structure 11. Determine whether each pressure data meets the first preset condition. If so, proceed to Step 2. The first preset condition is P1 > P1 > P0 > P3 > 10 kPa. If not, generate a first control command, which is used to instruct the flow regulating valve 4 on the air injection pipe 9, the exhaust pipe 10 and the discharge structure 12 to be adjusted sequentially. Step 2: Obtain the inlet gas flow rate Q1 of the gas injection pipe 9, the outlet gas flow rate Q2 of the exhaust pipe 10, and the mixed gas flow rate Q3 of the fully developed structure 11. Based on Q1, Q2, Q3, P0, and the gas temperature T0 inside the target measurement environment, calculate the gas flow rate Q4 of the primary sampling structure 6. Convert the gas velocity V2 of the primary sampling structure 6 according to Q4, and determine whether V2 meets the second preset condition. If so, proceed to step 3. The second preset condition is that the difference between V2 and the gas velocity V1 inside the target measurement environment is less than a preset threshold, for example, the preset threshold is set to 5%. Otherwise, a second control command is generated, which is used to instruct the opening degree of the flow regulating valve 4 on the discharge structure 12; Step 3: Obtain the gas temperature T1 of the gas injection pipe 9, the gas temperature T2 of the gas discharge pipe 10, and the mixed gas temperature T3 of the fully developed structure 11. Determine whether each temperature data meets the third preset condition. If so, proceed to step 4. The third preset condition is that both T1 and T2 meet the system operation requirements and T3 is within the preset temperature range, such as 100 to 150°C. If not, a third control command is generated, which is used to indicate the adjustment of the heating power of the heating jacket, and when the heating power exceeds the limit, the opening of the flow regulating valve 4 on the air injection pipe 9 and the exhaust pipe 10 is adjusted in sequence.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An aerosol sampling and measurement system suitable for vapor flow systems, characterized in that, It includes a primary sampling structure (6), a gas filling structure (7), a fully developed structure (11), an emission structure (12), a secondary sampling structure, a measurement and control host (20), and an aerosol measurement host (19); The sampling end of the primary sampling structure (6) is arranged in the target measurement environment. The gas filling structure (7) is arranged downstream of the primary sampling structure (6). A heating jacket is provided on its outer side and an exhaust pipe (10) and an injection pipe (9) are connected to its outer peripheral wall. The gas filling structure (7) is connected to the air inlet of the primary sampling structure (6) and the air outlet of the injection pipe (9) to form convection. The heating jacket is electrically connected to a DC power supply (8). The fully developed structure (11) is arranged downstream of the gas filling structure (7), the sampling end of the secondary sampling structure is arranged in the fully developed structure (11), and a measurement probe (14) is provided downstream of the secondary sampling structure. The measurement probe (14) is communicatively connected to the aerosol measurement host (19). The emission structure (12) is arranged downstream of the fully developed structure (11). The exhaust pipe (10), the air injection pipe (9) and the emission structure (12) are all equipped with a flow meter, a pressure sensing device (2), a temperature sensing device (1) and a flow regulating valve (4). The flow meter, the pressure sensing device (2) and the temperature sensing device (1) are all connected to the signal input terminal of the control host (20). The signal output terminal of the control host (20) is connected to the flow regulating valve (4).

2. The aerosol sampling and measurement system suitable for vapor flow systems as described in claim 1, characterized in that, The sampling ends of the primary sampling structure (6) and the secondary sampling structure are both L-shaped.

3. The aerosol sampling and measurement system suitable for vapor flow systems as described in claim 1, characterized in that, Downstream of the secondary sampling structure, a condensate tank (15) and a steam-water separator (16) are also installed in sequence.

4. The aerosol sampling and measurement system suitable for vapor flow systems as described in claim 1, characterized in that, The gas filling structure (7) includes an outer cylinder, which has a central flow channel and a multi-stage stepped flow channel distributed in a ring outside the central flow channel. The exhaust pipe (10) and the gas injection pipe (9) are both connected to the multi-stage stepped flow channel. The multi-stage stepped flow channel is connected to the central flow channel. The first end of the central flow channel is connected to the first-stage sampling structure (6), and the second end of the central flow channel is connected to the fully developed structure (11).

5. The aerosol sampling and measurement system suitable for vapor flow systems as described in claim 4, characterized in that, The inner diameter of the first end of the central flow channel is smaller than the inner diameter of its second end, the inner diameter of the outlet of the first-stage sampling structure (6) is smaller than the inner diameter of the first end of the central flow channel, and the inner diameter of the inlet of the fully developed structure (11) is equal to the inner diameter of the second end of the central flow channel.

6. The aerosol sampling and measurement system for vapor flow systems as described in claim 5, characterized in that, The outer cylinder is provided with several inner cylinders with different outer diameters. The inner cylinders are arranged in a stepped manner and together with the inner wall of the outer cylinder, they form a multi-level stepped flow channel. The inner cylinder with a larger outer diameter is arranged near the second end of the central flow channel, and the inner cylinder with a smaller outer diameter is arranged near the first end of the central flow channel. The air injection pipe (9) is arranged on the outside of the inner cylinder with a larger outer diameter, and the exhaust pipe (10) is arranged on the outside of the inner cylinder with a smaller outer diameter.

7. The aerosol sampling and measurement system suitable for vapor flow systems as described in claim 6, characterized in that, A gas guide ring rib (25) is sleeved on the outer side of the first end of the inner cylinder. A plurality of flow guide holes (26) are opened on both the gas guide ring rib (25) and the second end of the inner cylinder. The flow guide holes (26) have oblique openings to form oblique flow channels that intersect with the multi-stage stepped flow channels and connect to the central flow channel. The oblique flow channels are located between adjacent inner cylinders.

8. The aerosol sampling and measurement system for vapor flow systems as described in claim 6, characterized in that, The outer side of the inner cylinder is fitted with a flow distribution ring rib (24), and the flow distribution ring rib (24) is provided with a number of evenly distributed flow distribution holes (27).

9. A control method for an aerosol sampling and measurement system suitable for a vapor flow system as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Provided that the pressure, flow rate and temperature of the gas inside the gas filling structure (7) and the fully developed structure (11) meet the experimental requirements, the ball valve (5) on the secondary sampling structure is opened; Obtain the gas flow rate Q1 of the gas injection pipe (9), the gas flow rate Q2 of the gas discharge pipe (10) and the gas flow rate Q4 of the first-stage sampling structure (6), and calculate the mixed gas ratio of the fully developed structure (11). The density of the mixed gas is calculated based on the mixed gas ratio and mixed gas temperature of the fully developed structure (11); The flow rate of the downstream gas in the secondary sampling structure is adjusted based on the density of the mixed gas to meet the density requirements of the particle size analyzer. The actual aerosol particle size distribution is calculated based on the dilution ratio and the original aerosol particle size distribution. The dilution ratio is determined based on the flow rate adjustment of the gas downstream of the secondary sampling structure.

10. The control method for an aerosol sampling and measurement system applicable to a vapor flow system as described in claim 9, characterized in that, The steps to build a scenario that meets the experimental requirements are as follows: Step 1: Obtain the pressure data P0 inside the target measurement environment, the pressure data P1 inside the air injection pipe (9), the pressure data P2 inside the exhaust pipe (10), and the pressure data P3 inside the fully developed structure (11). Determine whether each pressure data meets the first preset condition. If so, proceed to step 2. The first preset condition is P1 > P2 > P0 > P3 > 10 kPa. If not, generate a first control command, which is used to instruct the opening degree of the flow regulating valve (4) on the air injection pipe (9), the exhaust pipe (10) and the discharge structure (12) in sequence; Step 2: Obtain the gas flow rate Q1 of the gas injection pipe (9), the gas flow rate Q2 of the gas discharge pipe (10), and the mixed gas flow rate Q3 of the fully developed structure (11). Based on Q1, Q2, Q3, P0 and the gas temperature T0 inside the target measurement environment, calculate the gas flow rate Q4 of the primary sampling structure (6). Calculate the gas velocity V2 of the primary sampling structure (6) based on Q4. Determine whether V2 meets the second preset condition. If so, proceed to step 3. The second preset condition is that the difference between V2 and the gas velocity V1 inside the target measurement environment is less than a preset threshold. Otherwise, a second control command is generated, which is used to instruct the opening degree of the flow regulating valve (4) on the regulating discharge structure (12); Step 3: Obtain the gas temperature T1 of the gas injection pipe (9), the gas temperature T2 of the gas discharge pipe (10), and the mixed gas temperature T3 of the fully developed structure (11). Determine whether each temperature data meets the third preset condition. If so, proceed to step 4. The third preset condition is that both T1 and T2 meet the system operation requirements and T3 is within the preset temperature range. If not, a third control command is generated, which is used to indicate the adjustment of the heating power of the heating jacket, and when the heating power exceeds the limit, the opening of the flow regulating valve (4) on the air injection pipe (9) and the exhaust pipe (10) is adjusted in sequence.

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