Aerosol sampling measurement device for a closed space containing steam

Abstract

This invention discloses a vapor-containing enclosed space aerosol sampling and measurement device, comprising: an aerosol sampling tube extending into the enclosed space; a measurement unit connected to the aerosol sampling tube via pipelines; a particle size analyzer connected to the measurement unit; a calibration particle container located at the inlet of the measurement unit; a condensate washing tank, a drying tube, and a flow controller sequentially connected to the measurement unit via pipelines; and an injection and purging pipeline connected to the aerosol sampling tube. Compared to the prior art, in this invention's vapor-containing enclosed space aerosol sampling and measurement device, a three-stage condensate washing tank, a drying tube, and a flow controller are connected downstream of the measuring instrument. This allows for the condensation of vapor in the sampled gas and the filtration of solid dust, ensuring that the air entering the flow controller is low-temperature, dry, and pure. This enables effective control of the sampled gas flow rate, ensuring the accuracy of aerosol concentration and particle size distribution measurements in the vapor-containing mixed sampled gas.

Description

Technical Field

[0001] This invention belongs to the field of aerosol measurement technology, and more specifically, this invention relates to a device for sampling and measuring aerosols in a closed space containing steam. Background Technology

[0002] In the event of a major breach in the primary circuit of a nuclear power plant, a large, closed gaseous space with high temperature, high pressure, and high humidity is formed inside the containment. Accurately measuring the aerosol concentration and particle size distribution at different locations within this large, closed gaseous space with high temperature, high pressure, and high humidity is crucial for analyzing the natural settling process of aerosols inside the containment under accident conditions.

[0003] In related technologies, the main functions of aerosol sampling and measurement devices in enclosed spaces include: (1) measuring aerosol concentration and particle size distribution by means of scattering spectroscopy analysis, charged low-pressure impaction analysis, filter membrane weighing, extinction measurement, etc.; (2) controlling the sampling gas flow rate by setting an orifice plate in the sampling tube and replenishing the sampling tube with gas; (3) realizing high-concentration aerosol measurement by setting a diluent in the sampling tube at the inlet of the measuring equipment; (4) arranging a heat tracing and insulation layer in the sampling tube, and controlling the temperature of the sampling tube wall surface through a temperature control device to prevent steam condensation.

[0004] However, the closed-space aerosol sampling and measurement devices of the relevant technologies have the following problems: (1) Measurement equipment such as particle size analyzers used to measure aerosol concentration needs to control the sampling gas flow rate to a set value. For aerosol sampling gas, which is a mixture of steam, air and solid dust, the direct entry of the steam-containing sampling gas into the flow control module inside the measurement equipment will cause damage to the equipment and affect the measurement results. The damage caused by steam can be avoided by the traditional filter membrane weighing measurement method. However, the filter membrane weighing measurement method can only obtain the aerosol mass concentration and cannot obtain the particle size distribution. Conventional flow meters cannot accurately measure the flow rate of the mixture of air and steam, resulting in the failure of the aerosol concentration and particle size distribution measurement results. The existing method of adding an orifice plate and a gas-liquid separation device to the sampling tube will cause loss of aerosol particles in the sampled gas, resulting in measurement deviation; (2) There are large differences in the thermodynamic parameters and aerosol concentration distribution at different spatial locations in a large gas phase space. When switching sampling tubes to measure the aerosol concentration at different locations, the sampled gases at multiple measuring points interfere with each other, causing measurement deviation; (3) No special sampling calibration pipeline is added upstream of the measuring equipment for instrument calibration before use.

[0005] In view of this, it is indeed necessary to provide a vapor-containing enclosed space aerosol sampling and measurement device that can accurately measure the aerosol concentration and particle size distribution in a vapor-containing sampled gas. Summary of the Invention

[0006] The purpose of this invention is to overcome at least one defect in the prior art and provide a vapor-containing enclosed space aerosol sampling and measuring device that can accurately measure the aerosol concentration and particle size distribution in a vapor-containing sampled gas.

[0007] To achieve the above-mentioned objectives, the present invention provides a vapor-containing enclosed space aerosol sampling and measurement device, comprising: an aerosol sampling tube extending into the enclosed space; a measurement unit connected to the aerosol sampling tube via a pipeline; a particle size analyzer connected to the measurement unit; a calibration particle container disposed at the inlet of the measurement unit; a condensate washing tank, a drying tube, and a flow controller sequentially connected to the measurement unit via pipelines; and an injection and purging pipeline connected to the aerosol sampling tube.

[0008] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, the measurement unit is connected to the particle size spectrometer via transmitting and receiving optical fibers.

[0009] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, the inlet of the measurement unit is connected to the calibration particle container through a calibration pipeline and a shut-off valve.

[0010] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measuring device of the present invention, the pipeline between the aerosol sampling tube and the measuring unit is provided with a heat tracing and insulation layer.

[0011] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, a temperature sensor is provided on the outer wall of the pipeline between the aerosol sampling tube and the measurement unit, and the temperature sensor is connected to a temperature control device.

[0012] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, the condensate washing tank is a three-stage condensate washing tank, the inlet pipe of the three-stage condensate washing tank extends to the bottom of the tank body, the outlet pipe is located at the top of the tank body, and the coolant in the tank body is demineralized water.

[0013] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, the bottom of the condensate washing tank is connected to a water injection pipe and a drainage pipe, and the water injection pipe is connected to a water replenishment tank through a water supply pump.

[0014] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measuring device of the present invention, the drying tube is provided with hygroscopic color-changing silica gel, and the color change of the hygroscopic silica gel particles is used to determine whether the moisture in the sampled gas has been completely removed.

[0015] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, the flow controller is provided with a control device for setting the controlled flow rate.

[0016] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, a plurality of aerosol sampling tubes are provided at intervals in the enclosed space. The plurality of aerosol sampling tubes are respectively connected to a sampling tube multi-way valve through pipelines, and are connected to the measurement unit through the sampling tube multi-way valve. The measurement unit is sequentially connected to the condensate washing tank, the drying tube and the flow controller through pipelines.

[0017] According to one embodiment of the vapor-containing enclosed space aerosol sampling and measuring device of the present invention, the pipeline between the aerosol sampling tube and the measuring unit is respectively connected to the gas injection and purging tube through a multi-way valve, and the gas injection and purging tube is connected to a dryer, a pressure reducing valve, a gas storage tank and an air compressor.

[0018] Compared to existing technologies, the aerosol sampling and measurement device for a steam-containing enclosed space of the present invention has a condensate washing tank, a drying tube, and a flow controller connected downstream of the measurement unit. The condensate washing tank and the drying tube can condense the steam in the sampled gas and filter the solid dust, ensuring that the air entering the flow controller is low-temperature, dry, and pure. The flow controller can effectively control the flow rate of the sampled gas, ensuring the accuracy of the measurement of aerosol concentration and particle size distribution in the steam-containing mixed sampled gas. Attached Figure Description

[0019] The following, in conjunction with the accompanying drawings and specific embodiments, provides a detailed description of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention and its technical effects, wherein:

[0020] Figure 1 This is a schematic diagram of the structure of the vapor-containing enclosed space aerosol sampling and measurement device of the present invention.

[0021] 1--Sealed space; 2--Aerosol sampling tube; 3--Sampling tube shut-off valve; 4--Injection pipeline shut-off valve; 5--Temperature sensor; 6--Sampling tube multi-way valve; 7--Thermostat; 8--Temperature sensor compensation wire; 9--Calibration particle container; 10--Calibration pipeline; 11--Measuring unit; 12--Condensate washing tank; 13--Drying tube; 14--Digital display controller; 15--Flow controller; 16--Drainage pipeline; 17--Water supply pump; 18--Make-up water tank; 19--Transmitting and receiving optical fibers; 20--Particle size spectrometer; 21--Pressure gauge; 22--Air compressor; 23--Air storage tank; 24--Pressure reducing valve; 25--Dryer; 26--Injection and purging tube. Detailed Implementation

[0022] To make the objectives, technical solutions, and effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are merely for explaining the invention and are not intended to limit the invention.

[0023] Please refer to Figure 1 As shown, the present invention provides an aerosol sampling and measurement device for a closed space containing steam, comprising: an aerosol sampling tube 2 extending into a closed space 1; a measurement unit 11 connected to the aerosol sampling tube 2 via a pipeline; a particle size analyzer 20 connected to the measurement unit 11; a calibration particle container 9 disposed at the inlet of the measurement unit 11; a condensate washing tank 12, a drying tube 13 and a flow controller 15 sequentially connected to the measurement unit 11 via pipelines; and an injection and purging tube 26 connected to the aerosol sampling tube 2.

[0024] The aerosol sampling tube 2 extends into the sealed space 1 to deliver the sampled gas into the measurement unit 11. The aerosol sampling tube 2 can be made of stainless steel, with an inner diameter preferably between 4mm and 8mm. A sampling tube shut-off valve 3 is installed on the aerosol sampling tube 2 outside the sealed space 1, located close to the outer wall of the sealed space 1. The sampling tube shut-off valve 3 is made of stainless steel and is used to control the opening and closing of the aerosol sampling tube 2. The sealed space 1 is a high-temperature, high-pressure, vapor-containing gas phase space. After the sampling tube shut-off valve 3 is opened, the sampled gas enters the measurement unit 11 through the aerosol sampling tube 2, and is discharged into the atmosphere after passing through the condensate washing tank 12, the drying tube 13, and the flow controller 15.

[0025] The particle size spectrometer 20 is an aerosol concentration measurement device, connected to the measurement unit 11 via transmitting and receiving optical fibers 19. It measures aerosol concentration and particle size distribution using scattering spectroscopy analysis. The measurement unit 11 is a heat-resistant steel structure, containing a light source (preferably a white light source) for transmitting and receiving. Vapor-containing aerosol sampling gas does not enter the main unit of the particle size spectrometer 20, thus preventing damage to the measurement equipment.

[0026] The inlet of the measuring unit 11 is connected to a calibration particle container 9 via a calibration pipeline 10 and a bypass pipeline shut-off valve (not labeled). The calibration particle container 9 is used to calibrate the sampled gas, and the bypass pipeline shut-off valve is used to control the opening and closing of the bypass pipeline. The material and requirements of the bypass pipeline are the same as those of the aerosol sampling tube 2.

[0027] According to one embodiment of the aerosol sampling and measurement device for a closed space containing steam of the present invention, the pipeline between the aerosol sampling tube 2 and the measurement unit 11 is provided with a heat tracing and insulation layer. A temperature sensor 5 is provided on the outer wall of the pipeline between the aerosol sampling tube 2 and the measurement unit 11. The temperature sensor 5 is connected to a temperature control device to monitor and control the temperature of the sampling pipeline wall. The temperature sensor 5 is preferably a K-type or T-type thermocouple. The range and accuracy of the temperature sensor 5 can be selected according to the actual operating conditions to avoid the influence of temperature changes in the sampled gas on the measurement results.

[0028] exist Figure 1 In the illustrated embodiment, the condensate wash tank 12 is a three-stage condensate wash tank or other suitable multi-stage condensate wash tank, preferably a three-stage condensate wash tank. The three-stage condensate wash tank 12 is connected to the outlet pipe of the measuring unit 11. After the sampled gas is measured, it removes vapor from the sampled gas through direct contact condensation and filters out aerosol particles from the sampled gas through water washing. A drying tube 13 is connected to the outlet of the three-stage condensate wash tank 12. The drying tube 13 contains hygroscopic color-changing silica gel to remove entrained droplets from the sampled gas at the outlet of the condensate wash tank 12. The color change of the silica gel particles indicates whether the moisture in the sampled gas has been completely removed. The flow controller 15 is connected to the outlet of the drying tube 13. The sampled gas after water washing and filtration is low-temperature, clean, and dry pure air, ensuring accurate and effective measurement by the flow controller 15.

[0029] The three-stage condensate wash tank 12 is made of stainless steel. The inlet pipe of the three-stage condensate wash tank 12 extends to the bottom of the tank, and the outlet pipe is located at the top of the tank. The coolant inside the tank is preferably demineralized water, and the liquid level must reach 4 / 5 of the tank's volume. The height of a single condensate wash tank is not less than 0.36m, and the volume is not less than 0.004m³. 3 Each tank has a water injection pipe (not labeled) and a drain pipe 16 connected to its bottom. The water injection pipe is connected to a water replenishment tank 18 via a water supply pump 17. The volume of the water replenishment tank 17 is not less than the sum of the volumes of the three-stage condensate wash tanks 12. After prolonged measurement, if the coolant temperature in the three-stage condensate wash tank 12 rises and the condensation effect decreases, the tank can be filled or drained through the water supply and drainage pipes 16 and the valves installed on them.

[0030] According to one embodiment of the aerosol sampling and measurement device for a confined space containing steam of the present invention, the flow controller 15 is provided with a control device (digital display controller 14) for setting the controlled flow rate. The flow controller 15 is an air mass flow controller, which adjusts the sampling gas flow rate through a built-in valve. The range and accuracy of the flow controller 15 are determined according to the actual measurement environment. The flow controller 15 is equipped with a control device for setting the controlled flow rate, and the set value can be adjusted in real time according to the ambient temperature, pressure, and composition of the measured environment.

[0031] It should be noted that the sampling location and the number of sampling tubes can be designed according to the required spatial location and quantity. According to one embodiment of the aerosol sampling and measurement device for a closed space containing steam according to the present invention, a plurality of aerosol sampling tubes 2 are spaced apart in the closed space 1. Figure 1 The diagram shows three aerosol sampling tubes 2 spaced apart. The number of aerosol sampling tubes 2 can be adjusted according to actual needs to achieve rapid switching measurement of aerosol concentration at multiple points in a confined space. Multiple aerosol sampling tubes 2 are connected to a sampling tube multi-way valve 6 via pipelines, and then connected to a measurement unit 11 via the sampling tube multi-way valve 6. The measurement unit 11 is sequentially connected to a condensate washing tank 12, a drying tube 13, and a flow controller 15 via pipelines.

[0032] The pipeline between the aerosol sampling tube 2 and the measuring unit 11 is connected to the gas injection purge pipe 26 via a multi-way valve. The gas injection purge pipe 26 is connected to a dryer 25, a pressure reducing valve 24, a gas storage tank 23, and an air compressor 22. The outlet pipe of the air compressor 22 is connected to the gas storage tank 23. A pressure gauge 21 is installed on the top of the gas storage tank 23. The outlet pipe of the gas storage tank 23 is connected to the pressure reducing valve 24. The outlet pipe of the pressure reducing valve 24 is connected to the dryer 25. The outlet pipe of the dryer 25 is connected to the gas injection purge pipe 26. The gas injection purge pipe 26 is connected to all the gas sampling tubes 2 via multiple gas injection pipe shut-off valves 4.

[0033] After measurement at a single location point is completed, the gas injection purge tube 26 purges the sampling channel to prevent interference between the sampling gas and dust particles in different sampling tubes on the measurement results. Before purging, the sampling tube shut-off valve 3 is closed to prevent the sampling purge gas from entering the sealed space 1 and interfering with the area near the measurement point. Depending on actual needs, during the gas injection process of the sampling tube, the outlet pressure of the pressure reducing valve 24 should not be lower than 0.3 MPa g, and the injection time should not be less than 5 seconds. The material, dimensions, and usage conditions of the gas injection purge tube 26 are the same as those of the aerosol sampling tube 2. The material and specifications of the shut-off valve are the same as those of the sampling tube shut-off valve 3, and the gas injection pipeline shut-off valve 4 is positioned close to the aerosol sampling tube 2.

[0034] As can be seen from the above detailed description of the embodiments of the present invention, compared with the prior art, in the vapor-containing enclosed space aerosol sampling and measurement device of the present invention, the downstream of the measurement unit 11 is connected to a condensate washing tank 12, a drying tube 13 and a flow controller 15. The condensate washing tank 12 and the drying tube 13 can condense the vapor in the sampling gas and filter the solid dust, ensuring that the air entering the flow controller 15 is low temperature, dry and pure. The flow controller 15 can effectively control the flow rate of the sampling gas, ensuring the accuracy of the measurement of aerosol concentration and particle size distribution in the vapor-containing mixed sampling gas.

[0035] Based on the above principles, the present invention can also make appropriate changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A device for sampling and measuring aerosols in a confined space, characterized in that, The enclosed space aerosol sampling and measurement device includes: an aerosol sampling tube extending into the enclosed space, a measurement unit connected to the aerosol sampling tube via a pipeline, a particle size spectrometer connected to the measurement unit, and a condensate washing tank, a drying tube, and a flow controller connected to the measurement unit via pipelines. The measurement unit is connected to the particle size spectrometer via transmitting and receiving optical fibers.

2. The aerosol sampling and measuring device for a confined space according to claim 1, characterized in that, The inlet of the measurement unit is connected to a calibration particle container via pipelines and a shut-off valve.

3. The aerosol sampling and measuring device for a confined space according to claim 1, characterized in that, The pipeline between the aerosol sampling tube and the measuring unit is equipped with a heat tracing and insulation layer.

4. The aerosol sampling and measuring device for a confined space according to claim 3, characterized in that, A temperature sensor is provided on the outer wall of the pipeline between the aerosol sampling tube and the measuring unit, and the temperature sensor is connected to a temperature control device.

5. The aerosol sampling and measuring device for a confined space according to claim 1, characterized in that, The condensate washing tank is a three-stage condensate washing tank. The inlet pipe of the three-stage condensate washing tank extends to the bottom of the tank body, and the outlet pipe is located at the top of the tank body. The coolant in the tank body is demineralized water.

6. The aerosol sampling and measuring device for a confined space according to claim 5, characterized in that, The bottom of the condensate washing tank is connected to a water injection pipe, a drainage pipe, and a valve. The water injection pipe is connected to a water replenishment tank via a water pump.

7. The aerosol sampling and measuring device for a confined space according to claim 1, characterized in that, The drying tube contains hygroscopic color-changing silica gel, and the color change of the hygroscopic color-changing silica gel particles is used to determine whether the moisture in the sampled gas has been completely removed.

8. The aerosol sampling and measuring device for a confined space according to claim 1, characterized in that, The flow controller is equipped with a control device for setting the flow rate to be controlled.

9. The aerosol sampling and measuring device for a confined space according to any one of claims 1 to 8, characterized in that, Multiple aerosol sampling tubes are spaced apart in the enclosed space. The multiple aerosol sampling tubes are connected to a sampling tube multi-way valve through pipelines, and are connected to the measurement unit through the sampling tube multi-way valve.

10. The aerosol sampling and measuring device for a confined space according to claim 9, characterized in that, The pipeline between the aerosol sampling tube and the measuring unit is connected to the gas injection pipe multi-way valve, which is connected to a dryer, a pressure reducing valve, a gas storage tank, and an air compressor.

11. The aerosol sampling and measuring device for a confined space according to claim 10, characterized in that, The aerosol sampling tube is equipped with a sampling tube stop valve, which is located near the outer wall of the sealed space. Before purging, the sampling tube stop valve is closed. During the gas injection process of the sampling tube, the outlet pressure of the pressure reducing valve is not lower than 0.3 MPa, and the gas injection time is not less than 5 seconds.

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