A multifunctional composite measurement system and its application for measuring the filtration efficiency of different equipment

Abstract

The present invention provides a multifunctional composite measurement system and application for measuring the filtration efficiency of different equipment, and the measurement system includes subsystems such as an air branch, a steam branch, a test section, a sample distribution section, and a sampling section. The present invention provides a multi-branch sample distribution section and a multi-branch sampling section, so that the measurement system has multiple functions, and can test the filtration efficiency of the equipment to be tested on different types of samples to be tested, which is simpler and more convenient. According to the different types of samples to be tested, a specific sampling section is selected, and each sampling section is used to measure the concentration of aerosols, iodine, methyl iodide and other samples to be tested, respectively, without affecting each other. The multifunctional composite measurement system adopts a more targeted measurement method according to the characteristics of different types of samples to be tested. Without the need to modify the test device, by adjusting the position of the corresponding valve, the filtration efficiency of different filtering equipment on different types of samples to be tested, such as aerosols, iodine, methyl iodide, etc., can be measured.

Description

Technical Field

[0001] The invention relates to the technical field of aerosols, and in particular to a multifunctional composite measuring system for measuring the filtering efficiency of different equipment and its application. Background Art

[0002] In the prior art, if a hypothetical serious accident occurs in a nuclear power plant, the core loses cooling and melts. During the melting process, some radioactive fission products will enter the containment atmosphere along with water vapor and non-condensable gases, forming organic iodine and aerosols. The containment is the last containment barrier to prevent the release of radioactive substances into the environment in a nuclear power plant. If it fails due to an accident, the radioactive aerosols and organic iodine in the atmosphere of the containment will become the main carriers of radioactive atmospheric release. The removal characteristics of aerosols and organic iodine in nuclear accidents are directly related to the magnitude of the radioactive consequences after the accident. Under certain hypothetical accidents, as the last containment barrier to prevent the release of radioactive substances into the environment, the containment may continue to be overpressured and thus damaged. To prevent the containment from being damaged, one treatment mode is to release the gas in the containment when the containment pressure approaches the design threshold. In addition to air and steam, the released gas also includes various radioactive substances, among which representative radioactive substances include organic iodine and aerosols. In order to prevent the spillage of such radioactive materials, a containment filtration and exhaust system is usually provided in the design of the containment, which is mainly used to filter the radioactive materials in the gas released into the atmosphere from the containment.

[0003] In recent years, various institutions have optimized the design of the filtration and emission systems, and continuously improved their filtration efficiency for aerosols, organic iodine, etc. However, the existing commonly used filtration and emission equipment measurement systems are often used to measure the filtration efficiency of a certain type of specific fission products, and cannot effectively measure the filtration efficiency of different fission products separately. For different filtration and emission systems, a dedicated measurement system is required to measure the filtration capacity and efficiency of the filtration and emission system. When the substance to be measured is changed, the measurement system needs to be significantly modified, which brings great inconvenience.

[0004] Therefore, the prior art needs to be improved. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a multifunctional composite measurement system and application for measuring the filtration efficiency of different equipment. By setting up multiple parallel distribution and measurement branches and adopting different measurement methods, the filtration efficiency of various filtration equipment for different fission products is measured respectively, aiming to solve the technical problems of the existing commonly used filtration efficiency test methods and single test purposes of filtration emission equipment.

[0006] The technical solution of the present invention is as follows:

[0007] In the first aspect, the present invention provides a multifunctional composite measurement system for measuring the filtration efficiency of different equipment, which includes a steam branch, an air branch, a test section, a sample distribution section and a sampling section; the steam branch includes a steam generator, a steam superheater, a check valve and a flow meter; the air branch includes an air compressor, an air storage tank, a control valve and a compressed air heater; the sample distribution section includes an iodine / aerosol injection port and an air / steam / aerosol mixing box; the sampling section includes an inlet sampling device, an outlet sampling device, a mesh filter, an aerosol filter, a sampling washing bottle, a plate cooler, a condenser, a drying filter and a volume flow meter; the test section is used to install the equipment to be tested.

[0008] The multifunctional composite measurement system for measuring the filtration efficiency of different equipment, wherein the steam superheater is arranged downstream of the steam generator, the air storage tank is arranged downstream of the air compressor, and the air / steam / aerosol mixing box is arranged downstream of the iodine / aerosol injection port.

[0009] The multifunctional composite measurement system for measuring the filtration efficiency of different equipment, wherein the sampling section is divided into three branches, namely an aerosol measurement branch, an iodine vapor concentration measurement branch and a methyl iodide concentration measurement branch.

[0010] The multifunctional composite measurement system for measuring the filtration efficiency of different equipment, wherein the iodine / aerosol injection port is divided into three paths, respectively used to inject aerosol, iodine element and methyl iodide into the aerosol measurement branch, iodine vapor concentration measurement branch and methyl iodide concentration measurement branch; the inlet sampling device is divided into three paths, respectively connected to the aerosol measurement branch before filtration, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch; the outlet sampling device is divided into three paths, respectively connected to the aerosol measurement branch, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch after filtration.

[0011] The multifunctional composite measuring system for measuring the filtering efficiency of different equipment, wherein the equipment to be tested includes a Venturi scrubber, a bubbler, and an adsorption filter.

[0012] In a second aspect, the present invention also provides an application of a multifunctional composite measurement system for measuring the filtration efficiency of different devices, wherein the multifunctional composite measurement system as described above is applied to measure the filtration efficiency of different filtration devices for aerosols, elemental iodine, and methyl iodide.

[0013] The application of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment, wherein, when the multifunctional composite measurement system is used to measure the filtration efficiency of the equipment to be tested, the air branch is used to provide compressed air to the test section, and the steam branch is used to provide steam to the test section; after the air branch and the steam branch are combined, they flow through the air / steam / aerosol mixing box to mix the medium to be tested evenly, and then enter the equipment to be tested for filtration; wherein, an inlet sampling device is provided after the air / steam / aerosol mixing box to monitor the content of the medium to be tested before filtration, and an outlet sampling device is provided after the equipment to be tested to measure the content of the medium to be tested after filtration, and the filtration efficiency of the equipment to be tested is calculated by comparing the content before and after filtration.

[0014] The application of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment, wherein the aerosol measurement branch adopts a weighing method to measure the aerosol concentration, and the specific steps include: when sampling, the mixed gas first passes through the aerosol filter, and the aerosol is intercepted by the filter membrane; then the remaining gas flows into the plate heat exchanger and the condensate tank, and the gas flow is measured by the mass flow meter after drying; finally, by measuring the mass before and after the filter membrane of the aerosol filter, the total mass of the aerosol is obtained, and then the concentration of the aerosol is calculated according to the gas flow.

[0015] The application of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment, wherein the iodine vapor measurement branch adopts a spectrophotometer to measure the iodine vapor concentration, and the specific steps include: when sampling, the gas passes through a gas washing bottle filled with potassium iodide solution, and the iodine element is retained and contacts with iodide ions to generate I3 - The remaining gas continues to pass through the plate heat exchanger and condensate tank for drying, and then enters the mass flow meter to measure the flow rate before being discharged; finally, by comparing the standard I3 - The total mass of iodine vapor is obtained from the solution curve, and the concentration of iodine vapor is calculated based on the gas flow rate.

[0016] The application of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment, wherein the methyl iodide concentration measurement branch adopts gas chromatography technology to measure the methyl iodide concentration, and the specific steps include: when sampling, the gas is cooled by a plate heat exchanger, the flow value is measured by a mass flow meter, and then enters the gas chromatograph for analysis, and the methyl iodide concentration is calculated according to the analysis results and the gas flow rate.

[0017] Beneficial effects: The present invention provides a multifunctional composite measurement system and application for measuring the filtration efficiency of different equipment, and the multifunctional composite measurement system includes subsystems such as an air branch, a steam branch, a test section, a sample distribution section, and a sampling section. The present invention provides a multifunctional composite measurement system by setting a multi-branch sample distribution section and a multi-branch sampling section in the multifunctional composite measurement system, so that the measurement system has multiple functions, and can test the filtration efficiency of the equipment to be tested for different types of samples to be tested, which is simpler and more convenient. According to the different types of samples to be tested, a specific sampling section is selected, and each sampling section is used to measure the concentration of aerosols, iodine, methyl iodide and other samples to be tested, respectively. The operation is simple, and the test branches do not affect each other. The multifunctional composite measurement system provided by the present invention is suitable for various aerosol filtering equipment. According to the different characteristics of different types of samples to be tested, a more targeted measurement method is adopted. Without the need to modify the test device, by adjusting the position of the corresponding valve, the filtration efficiency of different filtering equipment for different types of samples to be tested, such as aerosols, iodine, methyl iodide, etc., can be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a multifunctional composite measurement system for measuring the filtration efficiency of different devices in an embodiment of the present invention.

[0019] Among them, 1-steam generator, 2-steam superheater, 3-check valve, 4-flow meter, 5-air compressor, 6-air storage tank, 7-control valve, 8-pressure measuring instrument, 9-temperature measuring instrument, 10-compressed air heater, 11-iodine / aerosol injection port, 12-air / steam / aerosol mixing box, 13-inlet sampling device, 14-equipment to be tested, 15-outlet sampling device, 16-grid filter, 17-stop valve, 18-aerosol filter, 19-gas washing bottle for sampling, 20-plate cooler, 21-condenser, 22-drying filter, 23-volume flow meter. DETAILED DESCRIPTION

[0020] The present invention provides a multifunctional composite measurement system and application for measuring the filtration efficiency of different devices. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] The embodiment of the present invention provides a multifunctional composite measurement system for measuring the filtration efficiency of different equipment, including a steam branch, an air branch, a test section, a sample delivery section and a sampling section, such as Figure 1As shown, it specifically includes: a steam branch consisting of a steam generator 1, a steam superheater 2 arranged downstream of the steam generator 1, a check valve 3, and a flow meter 4; an air branch consisting of an air compressor 5, an air storage tank 6 arranged downstream of the air compressor 5, a control valve 7, and a compressed air heater 10; a sample distribution section consisting of an iodine / aerosol injection port 11 and an air / steam / aerosol mixing box 12 arranged downstream of the iodine / aerosol injection port 11; a sampling section consisting of an inlet sampling device 13, an outlet sampling device 15, a mesh filter 16, an aerosol filter 18, a sampling washing bottle 19, a plate cooler 20, a condenser 21, a drying filter 22, and a volume flow meter 23; and a test section for installing the device to be tested 14. Among them, Figure 1 The inlet sampling device 13 is divided into three paths, which are respectively connected to the aerosol measurement branch before filtration, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch; the outlet sampling device 15 is also divided into three paths, which are respectively connected to the aerosol measurement branch after filtration, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch.

[0022] In some embodiments, the device to be tested includes an aerosol removal filter device, such as a venturi scrubber, a bubbler, an adsorption filter, etc., but is not limited thereto.

[0023] In some embodiments, the air branch is used to provide compressed air to the test section. After the compressed air flows out of the air compressor, it first passes through three-stage filtration to remove impurities in the air; then passes through a pressure reducing valve to reduce the pressure to the required working conditions for the test; then passes through a vortex flowmeter to measure the mass flow of the air; there is a regulating valve after the flowmeter to adjust the required compressed air flow; then the air is heated to the required test temperature by an air heater; a check valve is also provided at the end of the air branch to prevent backflow.

[0024] In some embodiments, the steam branch is used to provide steam to the test section, and together with the air branch, simulates the atmospheric environment under accident conditions in the containment. The steam is first heated by electric heating, and then connected to a pressure reducing valve to produce steam at the required pressure; then the required steam flow is set through a regulating valve; then the steam heater is connected to heat the steam to a slightly superheated state, and then the test section is connected through a check valve.

[0025] In some embodiments, the sample delivery section and the sampling section are used to provide the sample to be tested to the test section. The sampling section is divided into three paths, namely, an aerosol measurement branch, an iodine vapor concentration measurement branch, and a methyl iodide concentration measurement branch.

[0026] In some embodiments, the iodine / aerosol injection port is divided into three paths, which are respectively used to inject aerosol, elemental iodine and methyl iodide into the aerosol measurement branch, iodine vapor concentration measurement branch and methyl iodide concentration measurement branch; the inlet sampling device is divided into three paths, which are respectively connected to the aerosol measurement branch before filtration, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch; the outlet sampling device is divided into three paths, which are respectively connected to the aerosol measurement branch, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch after filtration.

[0027] In some embodiments, the test section is used to test the aerosol removal device. After the air branch and the steam branch are combined, they flow through the air / steam / aerosol mixing box to mix the medium to be tested evenly; then they enter the device to be tested to perform the aerosol removal device test; the remaining tail gas enters the exhaust port.

[0028] A sample distribution interface is provided in front of the air / steam / aerosol mixing box. During the test, aerosols, iodine vapor or methyl iodide, etc., enter the sample distribution section through different branches of the iodine / aerosol injection port. An inlet sampling device is provided after the air / steam / aerosol mixing box to monitor the medium content before filtration. An outlet sampling device is provided after the aerosol filtering equipment (such as a venturi scrubber, etc.) to measure the medium content after filtration. By comparing the content before and after filtration, the filtering effect of the equipment to be tested is analyzed.

[0029] In some embodiments, the aerosol measurement branch uses a weighing method to measure the aerosol concentration; the iodine vapor measurement branch uses a spectrophotometer to measure the iodine vapor concentration; and the methyl iodide gas measurement branch uses a gas chromatography technique to measure the methyl iodide concentration.

[0030] In some embodiments, the specific steps of measuring the aerosol concentration by weighing method in the aerosol measurement branch include: when sampling, the mixed gas first passes through the aerosol filter, and the aerosol is retained by the filter membrane; then the remaining gas flows into the plate heat exchanger and the condensate tank, and the gas flow rate is measured by the mass flow meter after drying; finally, the total mass of the aerosol is obtained by measuring the mass before and after the aerosol filter membrane, and then the concentration of the aerosol is calculated based on the gas flow rate.

[0031] In some embodiments, the specific steps of measuring the iodine vapor concentration by spectrophotometry in the iodine vapor measurement branch include: when sampling, the gas passes through a gas washing bottle filled with potassium iodide solution, and the iodine element is retained and contacts with iodide ions to generate I3 - The remaining gas continues to pass through the plate heat exchanger and condensate tank for drying, and then enters the mass flow meter to measure the flow rate before being discharged; finally, by comparing the standard I3 - The total mass of iodine vapor is obtained from the solution curve, and the concentration of iodine vapor is calculated based on the gas flow rate.

[0032] In some embodiments, the specific steps of measuring the methyl iodide concentration using gas chromatography technology in the methyl iodide concentration measurement branch include: when sampling, the gas is cooled by a plate heat exchanger, the flow value is measured by a mass flow meter, and then enters the gas chromatograph for analysis, and the methyl iodide concentration is calculated based on the analysis results and the gas flow rate.

[0033] An embodiment of the present invention also provides an application of a multifunctional composite measurement system for measuring the filtration efficiency of different devices. The multifunctional composite measurement system as described above is applied to measure the filtration efficiency of different filtration devices for aerosols, elemental iodine, and methyl iodide, but is not limited thereto.

[0034] In some embodiments, the multifunctional composite measurement system is applied to measure the filtration efficiency of different types of filtration equipment in the containment filtration and exhaust system of a pressurized water reactor nuclear power plant for aerosols, elemental iodine, and methyl iodide.

[0035] In some implementations, the multifunctional composite measurement system may be appropriately modified according to actual conditions to adapt to the measurement of the filtration efficiency of other radioactive substances.

[0036] In summary, the present invention provides a multifunctional composite measurement system and application for measuring the filtration efficiency of different equipment, and the multifunctional composite measurement system includes subsystems such as an air branch, a steam branch, a test section, a sample distribution section, and a sampling section. The present invention provides a multifunctional composite measurement system by setting a multi-branch sample distribution section and a multi-branch sampling section in the multifunctional composite measurement system, so that the measurement system has multiple functions, and can test the filtration efficiency of the equipment to be tested for different types of samples to be tested, which is simpler and more convenient. According to the different types of samples to be tested, a specific sampling section is selected, and each sampling section is used to measure the concentration of aerosols, iodine, methyl iodide and other samples to be tested, respectively. The operation is simple, and the test branches do not affect each other. The multifunctional composite measurement system provided by the present invention is suitable for various aerosol filtering equipment. According to the different characteristics of different types of samples to be tested, a more targeted measurement method is adopted. Without the need to modify the test device, by adjusting the position of the corresponding valve, the filtration efficiency of different filtering equipment for different types of samples to be tested, such as aerosols, iodine, methyl iodide, etc., can be measured.

[0037] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A multifunctional composite measurement system for measuring the filtration efficiency of different equipment, characterized in that: It includes a steam branch, an air branch, a test section, a sample distribution section and a sampling section; the steam branch includes a steam generator, a steam superheater, a check valve and a flow meter; the air branch includes an air compressor, an air storage tank, a control valve and a compressed air heater; the sample distribution section includes an iodine / aerosol injection port and an air / steam / aerosol mixing box; the sampling section includes an inlet sampling device, an outlet sampling device, a mesh filter, an aerosol filter, a sampling washing bottle, a plate cooler, a condenser, a drying filter and a volume flow meter; the test section is used to install the equipment to be tested; The steam superheater is arranged downstream of the steam generator, the air storage tank is arranged downstream of the air compressor, and the air / steam / aerosol mixing box is arranged downstream of the iodine / aerosol injection port; The sampling section is divided into three branches, namely, an aerosol measurement branch, an iodine vapor concentration measurement branch and a methyl iodide concentration measurement branch; The iodine / aerosol injection port is divided into three paths, which are respectively used to inject aerosol, iodine element and methyl iodide into the aerosol measurement branch, iodine vapor concentration measurement branch and methyl iodide concentration measurement branch; the inlet sampling device is divided into three paths, which are respectively connected to the aerosol measurement branch before filtration, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch; the outlet sampling device is divided into three paths, which are respectively connected to the aerosol measurement branch, the iodine vapor concentration measurement branch and the methyl iodide concentration measurement branch after filtration.

2. The multifunctional composite measurement system for measuring the filtration efficiency of different equipment according to claim 1, characterized in that: The equipment to be tested includes a venturi scrubber, a bubbler, and an adsorption filter.

3. An application of a multifunctional composite measurement system for measuring the filtration efficiency of different devices, characterized in that: The multifunctional composite measuring system as claimed in claim 1 or 2 is applied to measure the filtering efficiency of different filtering devices for aerosol, elemental iodine and methyl iodide.

4. The use of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment according to claim 3 is characterized in that: When the multifunctional composite measuring system is used to measure the filtration efficiency of the equipment to be tested, the air branch is used to provide compressed air to the test section, and the steam branch is used to provide steam to the test section; After the air branch and the steam branch are combined, they flow through the air / steam / aerosol mixing box to mix the medium to be tested evenly, and then enter the equipment to be tested for filtration; wherein, an inlet sampling device is provided behind the air / steam / aerosol mixing box to monitor the content of the medium to be tested before filtration, and an outlet sampling device is provided behind the equipment to be tested to measure the content of the medium to be tested after filtration, and the filtration efficiency of the equipment to be tested is calculated by comparing the content before and after filtration.

5. The use of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment according to claim 3, characterized in that: The aerosol measurement branch uses the weighing method to measure the aerosol concentration. The specific steps include: when sampling, the mixed gas first passes through the aerosol filter, and the aerosol is retained by the filter membrane; then the remaining gas flows into the plate heat exchanger and the condensate tank, and the gas flow is measured by the mass flow meter after drying; finally, the total mass of the aerosol is obtained by measuring the mass before and after the aerosol filter membrane, and then the aerosol concentration is calculated based on the gas flow rate.

6. The use of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment according to claim 3, characterized in that: The iodine vapor measurement branch uses a spectrophotometer to measure the iodine vapor concentration. The specific steps include: when sampling, the gas passes through a gas washing bottle filled with potassium iodide solution, the iodine element is retained, and comes into contact with iodine ions to generate I3- and display yellow; the remaining gas continues to pass through the plate heat exchanger and condensate tank for drying, and then enters the mass flowmeter to measure the flow rate and then is discharged; finally, by comparing with the standard I3- solution curve, the total mass of iodine vapor is obtained, and then the iodine vapor concentration is calculated based on the gas flow rate.

7. The use of the multifunctional composite measurement system for measuring the filtration efficiency of different equipment according to claim 3, characterized in that: The methyl iodide concentration measurement branch uses gas chromatography technology to measure the methyl iodide concentration. The specific steps include: when sampling, the gas is cooled through a plate heat exchanger, the flow value is measured by a mass flow meter, and then enters a gas chromatograph for analysis. The concentration of methyl iodide is calculated based on the analysis results and the gas flow rate.

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