A method and apparatus for verification and calibration of gas concentrations

Abstract

The present application relates to a kind of verification and calibration method of gas concentration, comprising the following steps: trace gas is mixed with diluent gas according to predetermined proportion, and the mixed gas is sampled;The concentration of trace gas in the sampled mixed gas is measured by gas chromatograph calibrated by standard curve;The predetermined proportion of the mixture is modified, and the concentration of trace gas in the modified mixed gas is repeatedly measured;The measured concentration of trace gas before and after modification is linearly fitted with the corresponding mixing ratio, to calculate the concentration of trace gas when the diluent gas in the mixed gas is zero;The calculated concentration of trace gas is compared with the concentration of trace gas given by the manufacturer, to calculate correction factor, and the present application also relates to a kind of verification and calibration device of gas concentration, using a kind of verification and calibration method and device of gas concentration can verify and calibrate the concentration of trace gas given by the manufacturer.

Description

Technical Field

[0001] This invention belongs to the field of air purification and radiation safety technology, specifically relating to a method and apparatus for verifying and calibrating gas concentration. Background Technology

[0002] Currently, both internationally and domestically, leakage measurement tests in the main control room of nuclear power plants require the use of tracer gases with "known concentrations." These "known concentrations" are provided by the tracer gas manufacturers, but their reliability cannot be verified. Since this "known concentration" is a crucial parameter in the final measurement result calculation, its reliability needs to be effectively guaranteed.

[0003] However, there is still no effective method, both internationally and domestically, for verifying the reliability of the "known concentration" of tracer gas from the manufacturer when conducting leak tests in the main control room of nuclear power plants. Summary of the Invention

[0004] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a method and system for verifying and calibrating gas concentration, which is used to measure the "known concentration" of tracer gas from the manufacturer, thereby ensuring the reliability of the measurement results of the unfiltered air leakage in the main control room of a nuclear power plant.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for verifying and calibrating gas concentration, comprising the steps of: mixing tracer gas and dilution gas in a predetermined ratio and sampling the mixed gas; measuring the concentration of tracer gas in the sampled mixed gas using a gas chromatograph calibrated with a standard curve; modifying the predetermined mixing ratio and repeatedly measuring the tracer gas concentration in the modified mixed gas; linearly fitting the tracer gas concentrations measured before and after modification with their corresponding mixing ratios to calculate the tracer gas concentration in the mixed gas when the dilution gas concentration is zero; comparing the calculated tracer gas concentration with the tracer gas concentration provided by the manufacturer and calculating a correction factor.

[0006] Furthermore, the diluting gas includes compressed air or nitrogen.

[0007] Furthermore, the predetermined ratio of the modified mixture is at least 5 times.

[0008] The present invention also provides a gas concentration verification and calibration device, comprising: a mixing sampling module for mixing tracer gas and dilution gas in a predetermined ratio and sampling the mixed gas; a measurement module for measuring the concentration of tracer gas in the sampled mixed gas using a gas chromatograph calibrated with a standard curve; a ratio modification module for modifying the predetermined mixing ratio and repeatedly measuring the tracer gas concentration in the modified mixed gas; a calculation module for linearly fitting the measured tracer gas concentrations before and after modification with their corresponding mixing ratios to calculate the tracer gas concentration in the mixed gas when the dilution gas concentration is zero; and a comparison module for comparing the calculated tracer gas concentration with the tracer gas concentration provided by the manufacturer and calculating a correction factor.

[0009] Furthermore, the mixing module includes a tracer gas bottle, a dilution gas bottle, and a gas mixer. The tracer gas bottle and the dilution gas bottle are respectively connected to the gas mixer. The tracer gas bottle contains tracer gas provided by the manufacturer, and the dilution gas bottle contains dilution gas.

[0010] Furthermore, a mass flow controller is provided at the connection point between the dilution gas bottle and the tracer gas bottle and the gas mixer to control the mixing ratio of the dilution gas and the tracer gas.

[0011] Furthermore, the hybrid sampling module also includes a sampling chamber, which is connected to a gas mixer so that after the tracer gas and dilution gas in the gas mixer are mixed, the mixed gas is delivered to the sampling chamber for sampling and measurement.

[0012] The advantages of this invention are as follows: by comparing the tracer gas concentration calculated by adjusting the mixing ratio with the tracer gas concentration given by the manufacturer, the missing gas concentration given by the manufacturer can be verified. When the verification result is inconsistent with the measurement result, a correction factor is calculated using the measurement result and the tracer gas concentration given by the manufacturer, thereby calibrating the tracer gas concentration given by the manufacturer. Thus, when conducting leak tests in the main control room of a nuclear power plant, the corrected tracer gas concentration can be used to calculate the leak test results in the main control room of the nuclear power plant. Attached Figure Description

[0013] Figure 1 This is a flowchart of the steps of a gas concentration verification and calibration method in this invention;

[0014] Figure 2 This is a schematic diagram of the structure of a gas concentration verification and calibration device according to the present invention. Detailed Implementation

[0015] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0016] like Figure 1-2 As shown, this invention proposes a method for verifying and calibrating gas concentration, comprising the following steps:

[0017] S1, the tracer gas and dilution gas are mixed in a predetermined ratio, and the mixed gas is sampled;

[0018] Specifically, tracer gas and dilution gas obtained from the manufacturer are introduced into the mixing container in a predetermined ratio to ensure thorough mixing within the container.

[0019] Furthermore, the diluent gas includes compressed air, nitrogen, or other gases.

[0020] S2, the concentration of tracer gas in the sampled mixed gas is measured by a gas chromatograph calibrated with a standard curve;

[0021] Specifically, after sampling the mixed gas, the concentration of the tracer gas in it is measured by a gas chromatograph calibrated with a standard curve (traceable to the standard concentration of the tracer gas), thus obtaining the concentration of the tracer gas in the mixed gas.

[0022] S3, Modify the predetermined mixing ratio, and repeatedly measure the concentration of tracer gas in the modified mixed gas;

[0023] Specifically, when mixing the tracer gas with the dilution gas, the predetermined mixing ratio is modified, and then the above steps S1 to S2 are repeated to obtain other ratios of mixed gas, and the concentration of tracer gas in other ratios of mixed gas is measured.

[0024] Furthermore, the predetermined mixing ratio is modified at least 5 times, that is, the predetermined ratio is modified at least 5 times, and then steps S1 to S2 are repeated to obtain at least 5 mixed gas ratios and corresponding tracer gas concentrations.

[0025] S4. Linearly fit the measured tracer gas concentrations before and after modification with their corresponding mixing ratios to calculate the tracer gas concentration in the mixed gas when the dilution gas is zero.

[0026] Specifically, after modifying the predetermined ratio in the mixed gas, the concentrations of the mixed gas before and after modification and their corresponding tracer gas concentrations are linearly fitted. This allows us to calculate the concentration of the tracer gas when the dilution gas in the mixed gas is zero, which can then be considered as the tracer gas concentration obtained through measurement.

[0027] S5. Compare the calculated tracer gas concentration with the tracer gas concentration given by the manufacturer, and calculate the correction factor.

[0028] Specifically, the tracer gas concentration provided by the manufacturer is a known parameter. By comparing the tracer gas concentration provided by the manufacturer with the tracer gas concentration calculated in step S4 (when the dilution gas is zero), the correction factor of the tracer gas concentration provided by the manufacturer can be calculated. Thus, when conducting leak tests in the main control room of a nuclear power plant, the correction factor can be used to correct the tracer gas concentration provided by the manufacturer.

[0029] Meanwhile, during the linear fitting process in step S4, the uncertainty of the measurement results can be determined based on the relevant factors of the linear fitting.

[0030] The present invention also provides a gas concentration verification and calibration device, comprising:

[0031] The mixed sampling module is used to mix the tracer gas and the dilution gas in a predetermined ratio and to sample the mixed gas.

[0032] The measurement module is used to measure the concentration of tracer gas in a sampled mixed gas using a gas chromatograph calibrated with a standard curve.

[0033] The ratio modification module is used to modify the predetermined ratio of the mixture and repeatedly measure the concentration of tracer gas in the modified mixed gas.

[0034] The estimation module is used to linearly fit the measured tracer gas concentrations before and after modification with their corresponding mixing ratios to estimate the tracer gas concentration in the mixed gas when the dilution gas is zero.

[0035] The comparison module is used to compare the calculated tracer gas concentration with the tracer gas concentration provided by the manufacturer and calculate the correction factor.

[0036] Furthermore, the mixing module includes a tracer gas bottle, a dilution gas bottle, and a gas mixer. The tracer gas bottle and the dilution gas bottle are respectively connected to the gas mixer. The tracer gas bottle contains tracer gas provided by the manufacturer, and the dilution gas bottle contains dilution gas. The tracer gas in the tracer gas bottle and the dilution gas in the dilution gas bottle are transported to the gas mixer for thorough mixing.

[0037] Furthermore, a mass flow controller is installed at the connection point between the dilution gas cylinder and the tracer gas cylinder and the gas mixer to control the mixing ratio of the dilution gas and the tracer gas.

[0038] Furthermore, the hybrid sampling module also includes a sampling chamber connected to a gas mixer, so that after the tracer gas and dilution gas in the gas mixer are mixed, the mixed gas is delivered to the sampling chamber for sampling and measurement.

[0039] As can be seen from the above embodiments, the present invention compares the tracer gas concentration calculated by adjusting the mixing ratio with the tracer gas concentration given by the manufacturer to verify the missing gas concentration given by the manufacturer. When the verification result is inconsistent with the measurement result, a correction factor is calculated using the measurement result and the tracer gas concentration given by the manufacturer, thereby calibrating the tracer gas concentration given by the manufacturer. Thus, when conducting leak tests in the main control room of a nuclear power plant, the corrected tracer gas concentration can be used to calculate the leak test results in the main control room of the nuclear power plant.

[0040] The present invention is not limited to the embodiments described in the specific implementation. Other implementation methods derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of the technical innovation of the present invention.

Claims

1. A method for verifying and calibrating gas concentration, characterized in that, include: The tracer gas and dilution gas are mixed in a predetermined ratio, and the mixed gas is sampled. The concentration of tracer gas in the sampled mixed gas was measured by a gas chromatograph calibrated with a standard curve. By modifying the predetermined mixing ratio, the concentration of tracer gas in the modified gas mixture is repeatedly measured to obtain the concentration of tracer gas in gas mixtures with other ratios. By linearly fitting the tracer gas concentrations measured before and after the modification with their corresponding mixing ratios, the concentration of the tracer gas in the mixed gas when the dilution gas is zero can be calculated. The calculated tracer gas concentration was compared with the tracer gas concentration provided by the manufacturer. When the verification results are inconsistent with the measurement results, a correction factor is calculated using the measurement results and the tracer gas concentration provided by the manufacturer, and then the tracer gas concentration provided by the manufacturer is calibrated.

2. The gas concentration verification and calibration method as described in claim 1, characterized in that: The diluent gas includes compressed air or nitrogen.

3. The gas concentration verification and calibration method as described in claim 1, characterized in that: The predetermined ratio of the modified mixture is at least 5 times.

4. A gas concentration verification and calibration device, characterized in that, include: The mixed sampling module is used to mix the tracer gas and the dilution gas in a predetermined ratio and to sample the mixed gas. The measurement module is used to measure the concentration of tracer gas in a sampled mixed gas using a gas chromatograph calibrated with a standard curve. The ratio modification module is used to modify the predetermined ratio of the mixture, repeatedly measure the tracer gas concentration in the modified gas mixture, and obtain the tracer gas concentration in other ratio gas mixtures. The estimation module is used to linearly fit the measured tracer gas concentrations before and after modification with their corresponding mixing ratios to estimate the tracer gas concentration in the mixed gas when the dilution gas is zero. The comparison module is used to compare the calculated tracer gas concentration with the tracer gas concentration given by the manufacturer. When the verification result is inconsistent with the measurement result, the module calculates a correction factor using the measurement result and the tracer gas concentration given by the manufacturer, and then calibrates the tracer gas concentration given by the manufacturer.

5. The gas concentration verification and calibration device as described in claim 4, characterized in that: The mixed sampling module includes a tracer gas bottle, a dilution gas bottle, and a gas mixer. The tracer gas bottle and the dilution gas bottle are respectively connected to the gas mixer. The tracer gas bottle contains tracer gas provided by the manufacturer, and the dilution gas bottle contains dilution gas.

6. The gas concentration verification and calibration device as described in claim 5, characterized in that: A mass flow controller is installed at the connection point between the dilution gas bottle and the tracer gas bottle and the gas mixer to control the mixing ratio of the dilution gas and the tracer gas.

7. The gas concentration verification and calibration device as described in claim 6, characterized in that: The mixed sampling module also includes a sampling chamber, which is connected to a gas mixer. After the tracer gas and dilution gas in the gas mixer are mixed, the mixed gas is delivered to the sampling chamber for sampling and measurement.

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