CN116499936A - Device and method for measuring retention efficiency of aerosol in gap - Google Patents

Device and method for measuring retention efficiency of aerosol in gap Download PDF

Info

Publication number
CN116499936A
CN116499936A CN202310286631.3A CN202310286631A CN116499936A CN 116499936 A CN116499936 A CN 116499936A CN 202310286631 A CN202310286631 A CN 202310286631A CN 116499936 A CN116499936 A CN 116499936A
Authority
CN
China
Prior art keywords
downstream
particle size
upstream
gas
pipe
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310286631.3A
Other languages
Chinese (zh)
Inventor
孙晓晖
齐志超
谷海峰
王一博
王辉
石雪垚
孙婧
蔡盟利
李精精
林盛盛
王贺南
常愿
张旭昊
雷宁博
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China Nuclear Power Engineering Co Ltd
Original Assignee
China Nuclear Power Engineering Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China Nuclear Power Engineering Co Ltd filed Critical China Nuclear Power Engineering Co Ltd
Priority to CN202310286631.3A priority Critical patent/CN116499936A/en
Publication of CN116499936A publication Critical patent/CN116499936A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/06—Investigating concentration of particle suspensions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/06—Investigating concentration of particle suspensions
    • G01N15/075—Investigating concentration of particle suspensions by optical means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Landscapes

  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Sampling And Sample Adjustment (AREA)

Abstract

The invention provides a device and a method for measuring the retention efficiency of aerosol in a gap, wherein an upstream pipe and a downstream pipe are connected between a particle size spectrometer and a reaction container, and a gap test structure and a gas equalizing structure are arranged on the downstream pipe; the control module is used for controlling the opening of the isolation valve on the upstream pipe and controlling the opening of the isolation valve so that the gas entering the particle size spectrometer from the upstream pipe meets the sampling flow requirement, controlling the closing of the upstream isolation valve and the opening of the downstream isolation valve, controlling the flow of air fed into the downstream pipe by the gas equalizing structure or the flow of partial gas discharged from the downstream pipe so that the gas entering the particle size spectrometer from the downstream pipe meets the sampling flow requirement, and calculating the retention efficiency of the aerosol in the gap test structure according to the aerosol concentration in the gas entering the upstream pipe and the downstream pipe detected by the particle size spectrometer respectively. The invention can reduce errors caused by uneven spatial distribution of the concentration of the upstream aerosol and avoid measurement errors among probes of different particle size spectrometers.

Description

Device and method for measuring retention efficiency of aerosol in gap
Technical Field
The invention relates to the technical field of nuclear power safety, in particular to a device and a method for measuring retention efficiency of aerosol in a gap.
Background
The phenomenon of aerosol retention in gaps is a great concern in the fields of safety design of nuclear power plants, transportation of radioactive material containers, and the like. The measurement technology of the in-gap aerosol retention efficiency is always one difficulty in researching the in-gap aerosol retention phenomenon. The main reasons for the difficulty of measurement are: 1) Error between different particle size spectrometers of an aerosol particle size spectrometer; 2) Under the severe accident condition of the nuclear power plant, the environmental conditions of the aerosol in the containment are high temperature, high pressure and high humidity, wherein the high temperature and the high pressure influence the parameters such as the concentration of the aerosol, and the high humidity environment is a challenge for the normal operation of the optical particle size spectrometer; 3) The gas flow in the gap is very small, and the flow requirement during the measurement of the spectrometer cannot be met.
Disclosure of Invention
The invention aims to solve the technical problems in the prior art, and provides a device for measuring the retention efficiency of aerosol in a gap so as to reduce errors caused by uneven spatial distribution of concentration of the aerosol at the upstream and avoid measurement errors among probes of different particle size spectrometers.
The technical scheme adopted for solving the technical problems of the invention is as follows:
The invention provides a device for measuring the retention efficiency of aerosol in a gap, which comprises:
a reaction vessel, a gap test structure, a gas equalizing structure, a particle size spectrometer and a control module,
an upstream pipe and a downstream pipe are connected between the inlet end of the particle size spectrometer and the reaction vessel, an upstream isolation valve is arranged on the upstream pipe, a downstream isolation valve is arranged on the downstream pipe, the reaction vessel is used for simulating the environment in the containment so as to output the gas in the reaction vessel to the upstream pipe or the downstream pipe, the particle size spectrometer is used for detecting the concentration of aerosol in the gas entering the reaction vessel from the upstream pipe or the downstream pipe,
the gap test structure and the gas equalizing structure are arranged on the downstream pipe, the gap test structure is used for simulating the gap environment of the containment vessel so as to retain part of aerosol in the gas flowing through the gap test structure, the gas equalizing structure is used for supplementing air into the downstream pipe or exhausting part of gas in the downstream pipe,
the control module is respectively connected with the upstream isolation valve, the downstream isolation valve, the gas equalizing structure and the particle size spectrometer, and is used for controlling the opening of the upstream isolation valve so as to enable gas entering the particle size spectrometer from an upstream pipe to meet the sampling flow requirement of the gas, acquiring the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer and calculating the aerosol concentration upstream of the gap test structure;
The control module is also used for controlling the closing of the upstream isolation valve and the opening of the downstream isolation valve, controlling the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas in the downstream pipe to be discharged, so that the gas entering the particle size spectrometer by the downstream pipe meets the sampling flow requirement, acquiring the concentration of the aerosol in the gas entering the downstream pipe by the particle size spectrometer, and calculating the concentration of the aerosol at the downstream of the gap test structure;
the control module is also used for calculating the retention efficiency of the aerosol in the gap test structure according to the calculated aerosol concentration at the upstream of the gap test structure and the calculated aerosol concentration at the downstream of the gap test structure.
Optionally, a condensing and drying structure and a flowmeter are also included,
the outlet end of the particle size spectrometer is connected with a post-treatment pipe, the condensation drying structure and the flowmeter are arranged on the post-treatment pipe and are sequentially arranged along the airflow direction, the condensation drying structure is used for condensing and removing steam in the gas entering the condensation drying structure, and the flowmeter is used for measuring the flow of the gas flowing through the condensation drying structure;
the control module is also connected to the flow meter,
the control module comprises an upstream pre-processing unit and an upstream post-processing unit which are electrically connected,
The control module controls the opening of the upstream isolation valve to enable the gas entering the particle size spectrometer from the upstream pipe to meet the sampling flow requirement, obtains the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer and calculates the aerosol concentration at the upstream of the gap test structure, and specifically comprises the following steps:
when the upstream preprocessing unit calculates that the gas flow entering the particle size spectrometer from the upstream pipe is the sampling flow of the particle size spectrometer, the flow q flowing through the flowmeter c ，
The upstream post-processing unit controls the opening of the upstream isolation valve and controls the opening of the upstream isolation valve so as to maintain the flow rate of the flowmeter at q c Acquiring aerosol concentration C in gas entering the upstream pipe detected by a particle size spectrometer readin And according to C readin Calculating an aerosol concentration upstream of the gap test structure;
the control module also comprises a downstream preprocessing unit, a judging unit and a downstream post-processing unit which are electrically connected in sequence,
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve to be opened, and controls the flow of air fed into the downstream pipe or the flow of gas discharged from the interior of the downstream pipe by the gas equalizing structure, so that the gas entering the particle size spectrometer by the downstream pipe meets the sampling flow requirement, and the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer is obtained and calculated, and the method specifically comprises the following steps:
The downstream pretreatment unit controls the downstream isolation valve to be opened and controls the gas equalizing structure to be closed, and obtains the flow q flowing through the flowmeter no And according to q no Calculating the gas flow q of the downstream pipe entering the particle size spectrometer 1 ，
The judging unit judges q 1 And the magnitude relation of the sampling flow of the particle size spectrometer,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer is less than that of the particle size spectrometer, the air flow rate q required to be supplemented for the air homogenizing structure is calculated c1 Controlling the opening of the gas equalizing structure and controlling the feeding flow of the gas equalizing structure to the downstream pipe to be q c1 Acquiring aerosol concentration C in gas entering the downstream pipe detected by a particle size spectrometer readout And according to C readout The aerosol concentration downstream of the gap test structure was calculated,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer is not less than the sampling flow rate, controlling the gas equalizing structure to be opened so as to discharge partial gas in the downstream pipe, and maintaining the flow rate to the flowmeter at q c Acquiring aerosol concentration C in gas entering downstream pipe detected by particle size spectrometer readout And according to C readout Calculating the concentration of aerosol at the downstream of the gap test structure;
the control module further comprises a calculation unit, the calculation unit is respectively and electrically connected with the upstream post-processing unit and the downstream post-processing unit, and the calculation unit calculates the retention efficiency of the aerosol in the gap test structure according to the calculated aerosol concentration at the upstream of the gap test structure and the calculated aerosol concentration at the downstream of the gap test structure.
Optionally, the upstream preprocessing unit calculates the flow q flowing through the flowmeter when the gas flow entering the particle size spectrometer from the upstream pipe is calculated to be the sampling flow of the particle size spectrometer by adopting the method (1) c ：
q c ＝ρ t2，p2 /(q sensor ρ t1，p1 (1-f s1 )) (1)
Wherein ρ is t1，p1 The density of the gas entering the particle size spectrometer from the upstream pipe is mg/L, wherein the pressure of the gas entering the particle size spectrometer from the upstream pipe is p1, and the temperature is t1;
f s1 the volume fraction of water vapor in the gas entering the particle size spectrometer for the upstream pipe;
ρ t2，p2 the air with the pressure of p2 and the temperature of t2 is formed by condensing and drying the air entering the particle size spectrometer from the upstream pipe, and mg/L is obtained.
Optionally, a downstream pre-processing unit obtains the flow q through the flow meter no And according to q no Calculating the gas flow q of the downstream pipe entering the particle size spectrometer 1 The calculation formula of (2) is shown as the formula:
q 1 ρ t3，p3 (1-f s2 )＝q no ρ t4，p4 (2)
wherein ρ is t3，p3 The density of the gas entering the particle size spectrometer from the downstream pipe is mg/L under the condition that the gas homogenizing structure is closed, wherein the pressure of the gas entering the particle size spectrometer from the downstream pipe is p3, and the temperature is t3;
f s2 when the gas equalizing structure is in a closed working condition, the downstream pipe enters the volume fraction of vapor in the gas of the particle size spectrometer;
ρ t4，p4 in order to ensure that the pressure formed by condensing and drying the gas entering the particle size spectrometer from the downstream pipe is p4 under the condition of closing the gas equalizing structure, and the density of the air with the temperature of t4 is mg/L.
Optionally, the upstream post-processing unit detects the aerosol concentration C in the gas into which the upstream tube enters according to a particle size spectrometer readin Calculation of aerosol concentration C upstream of a gap test structure in The formula of (2) is shown as formula (3):
C in ＝C reaain p in /p 1 (3)
wherein p is in The pressure of the gas in the reaction vessel, bar;
p 1 the pressure of the gas entering the particle size spectrometer at the upstream tube, bar.
Alternatively, the downstream post-processing unit determines q at the determination unit 1 When the sampling flow rate of the particle size spectrometer is less than that of the particle size spectrometer, the air flow rate q required to be supplemented for the air homogenizing structure is calculated by adopting the formula (4) c1 ：
q c1 ＝(q sensor -q 1 )ρ t5，p5 /ρ t6，p6 (4)
Wherein ρ is t5，p5 The density of the gas entering the particle size spectrometer from the downstream pipe is mg/L under the gas-equalizing structure gas-supplementing working condition, wherein the pressure of the gas entering the particle size spectrometer from the downstream pipe under the gas-equalizing structure gas-supplementing working condition is p3, and the temperature is t3;
ρ t6，p6 under the air-supplementing working condition of the air-homogenizing structure, the pressure formed by condensing and drying the air entering the particle size spectrometer from the downstream pipe is p6, and the density of the air with the temperature of t6 is mg/L.
Alternatively, the downstream post-processing unit determines q at the determination unit 1 When the sampling flow rate of the particle size spectrometer is less than that of the gas entering the downstream pipe according to the detection of the particle size spectrometer, the concentration C of the aerosol in the gas entering the downstream pipe readout The formula for calculating the aerosol concentration downstream of the gap test structure is shown in formula (5):
C out ＝C readout (p in /p 2 )q sensor /q 1 (5)
Wherein p is 2 The pressure of the gas in the particle size spectrometer entering the downstream pipe is regulated by the pressure regulating valve.
Alternatively, the downstream post-processing unit determines q at the determination unit 1 When the sampling flow rate of the particle size spectrometer is not less than the sampling flow rate, calculating a gap according to the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometerThe formula for aerosol concentration downstream of the test structure is shown in formula (6):
C out ＝C readout (p in /p 3 ) (6)
wherein p is 3 The pressure of the gas entering the particle size spectrometer from the downstream pipe is bar under the exhaust working condition of the gas equalizing structure.
Optionally, the calculating unit calculates the retention efficiency P of the aerosol in the slit test structure according to the calculated aerosol concentration upstream of the slit test structure and the calculated aerosol concentration downstream of the slit test structure by using formula (7):
P＝1-C out /C in (7)。
optionally, temperature control mechanisms are arranged on the upstream pipe and the downstream pipe and used for controlling the temperature of the corresponding pipelines to be slightly higher than the temperature of the reaction vessel.
The invention also provides a method for measuring the retention efficiency of the aerosol in the gap by using the device, which comprises the following steps:
the control module controls the opening of the upstream isolation valve so that the gas entering the particle size spectrometer from the upstream pipe meets the sampling flow requirement, acquires the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer and calculates the aerosol concentration upstream of the gap test structure;
The control module controls the upstream isolation valve to be closed and controls the downstream isolation valve to be opened, and controls the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas in the downstream pipe to be discharged, so that the gas entering the particle size spectrometer by the downstream pipe meets the sampling flow requirement, the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer is obtained, and the aerosol concentration downstream of the gap test structure is calculated;
the control module calculates the retention efficiency of the aerosol in the gap test structure according to the calculated aerosol concentration at the upstream of the gap test structure and the calculated aerosol concentration at the downstream of the gap test structure.
Optionally, the outlet end of the particle size spectrometer is connected with a post-treatment pipe, the condensation drying structure and the flowmeter are arranged on the post-treatment pipe and are sequentially arranged along the airflow direction, the condensation drying structure is used for condensing and removing steam in the gas entering the condensation drying structure, and the flowmeter is used for measuring the flow of the gas flowing through the condensation drying structure;
the control module is also connected to the flow meter,
the control module comprises an upstream pre-processing unit and an upstream post-processing unit which are electrically connected,
the control module controls the opening of the upstream isolation valve to enable the gas entering the particle size spectrometer from the upstream pipe to meet the sampling flow requirement, obtains the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer and calculates the aerosol concentration at the upstream of the gap test structure, and specifically comprises the following steps:
When the upstream preprocessing unit calculates that the gas flow entering the particle size spectrometer from the upstream pipe is the sampling flow of the particle size spectrometer, the flow q flowing through the flowmeter c ，
The upstream post-processing unit controls the opening of the upstream isolation valve and controls the opening of the upstream isolation valve so as to maintain the flow rate of the flowmeter at q c Acquiring aerosol concentration C in gas entering the upstream pipe detected by a particle size spectrometer readin And according to C readin Calculating an aerosol concentration upstream of the gap test structure;
the control module also comprises a downstream preprocessing unit, a judging unit and a downstream post-processing unit which are electrically connected in sequence,
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve to be opened, and controls the flow of air fed into the downstream pipe or the flow of gas discharged from the interior of the downstream pipe by the gas equalizing structure, so that the gas entering the particle size spectrometer by the downstream pipe meets the sampling flow requirement, and the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer is obtained and calculated, and the method specifically comprises the following steps:
the downstream pretreatment unit controls the downstream isolation valve to be opened and controls the gas equalizing structure to be closed, and obtains the flow q flowing through the flowmeter no And according to q no Calculating the gas flow q of the downstream pipe entering the particle size spectrometer 1 ，
The judging unit judges q 1 And the magnitude relation of the sampling flow of the particle size spectrometer,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer is less than that of the particle size spectrometer, the air flow rate q required to be supplemented for the air homogenizing structure is calculated c1 Controlling the opening of the gas equalizing structure and controlling the feeding flow of the gas equalizing structure to the downstream pipe to be q c1 Acquiring aerosol concentration C in gas entering the downstream pipe detected by a particle size spectrometer readout And according to C readout The aerosol concentration downstream of the gap test structure was calculated,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer is not less than the sampling flow rate, controlling the gas equalizing structure to be opened so as to discharge partial gas in the downstream pipe, and maintaining the flow rate to the flowmeter at q c Acquiring aerosol concentration C in gas entering downstream pipe detected by particle size spectrometer readout And according to C readout Calculating the concentration of aerosol at the downstream of the gap test structure;
the control module further comprises a calculation unit, the calculation unit is respectively and electrically connected with the upstream post-processing unit and the downstream post-processing unit, and the calculation unit calculates the retention efficiency of the aerosol in the gap test structure according to the calculated aerosol concentration at the upstream of the gap test structure and the calculated aerosol concentration at the downstream of the gap test structure.
According to the invention, the pipeline is led out to the particle size spectrometer at the upstream and downstream of the gap test structure, and the downstream is provided with the gas equalizing structure to supplement air to the downstream pipe or discharge partial gas in the downstream pipe, so that the gas entering the particle size spectrometer from the downstream pipe meets the sampling flow requirement, and the concentration of the aerosol at the upstream and downstream of the gap test structure is directly measured by the particle size spectrometer. On the one hand, compared with the upstream sampling port arranged in the reaction container, the method reduces errors caused by uneven spatial distribution of the concentration of the upstream aerosol; on the other hand, compared with the method for measuring the concentration of the aerosol at the upstream and downstream of the gap test structure by using two particle size spectrometers, the method avoids the measurement error between probes of different particle size spectrometers.
Drawings
Fig. 1 is a schematic structural diagram of an apparatus for measuring the retention efficiency of aerosol in a gap according to embodiment 1 of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made more apparent, and the embodiments described in detail, but not necessarily all, in connection with the accompanying drawings. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.
In the description of the present invention, it should be noted that the orientation or positional relationship indicated by "upper" or the like is based on the orientation or positional relationship shown in the drawings, and is merely for convenience and simplicity of description, and is not meant to indicate or imply that the apparatus or element to be referred to must be provided with a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.
In the description of the present invention, the terms "first," "second," and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "connected," "configured," "mounted," "secured," and the like are to be construed broadly and may be either fixedly connected or detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood by those skilled in the art in specific cases.
The invention provides a device for measuring the retention efficiency of aerosol in a gap, which comprises:
A reaction vessel, a gap test structure, a gas equalizing structure, a particle size spectrometer and a control module,
an upstream pipe and a downstream pipe (the upstream pipe and the downstream pipe are arranged in parallel) are connected between the inlet end of the particle size spectrometer and the reaction vessel, an upstream isolation valve is arranged on the upstream pipe, a downstream isolation valve is arranged on the downstream pipe, the reaction vessel is used for simulating the environment in the containment so as to output the gas in the upstream pipe or the downstream pipe, the particle size spectrometer is used for detecting the concentration of aerosol in the gas entering the upstream pipe or the downstream pipe,
the gap test structure and the gas equalizing structure are arranged on the downstream pipe, the gap test structure is used for simulating the gap environment of the containment vessel so as to retain part of aerosol in the gas flowing through the gap test structure, the gas equalizing structure is used for supplementing air into the downstream pipe or exhausting part of gas in the downstream pipe,
the control module is respectively connected with the upstream isolation valve, the downstream isolation valve, the gas equalizing structure and the particle size spectrometer, and is used for controlling the opening of the upstream isolation valve so as to enable gas entering the particle size spectrometer from an upstream pipe to meet the sampling flow requirement of the gas, acquiring the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer and calculating the aerosol concentration upstream of the gap test structure;
The control module is also used for controlling the closing of the upstream isolation valve and the opening of the downstream isolation valve, controlling the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas in the downstream pipe to be discharged, so that the gas entering the particle size spectrometer by the downstream pipe meets the sampling flow requirement, acquiring the concentration of the aerosol in the gas entering the downstream pipe by the particle size spectrometer, and calculating the concentration of the aerosol at the downstream of the gap test structure;
the control module is also used for calculating the retention efficiency of the aerosol in the gap test structure according to the calculated aerosol concentration at the upstream of the gap test structure and the calculated aerosol concentration at the downstream of the gap test structure.
The invention also provides a method for measuring the retention efficiency of the aerosol in the gap by using the device, which comprises the following steps:
the control module controls the opening of the upstream isolation valve so that the gas entering the particle size spectrometer from the upstream pipe meets the sampling flow requirement, acquires the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer and calculates the aerosol concentration upstream of the gap test structure;
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve to be opened, and controls the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas in the downstream pipe to be discharged, so that the gas entering the particle size spectrometer by the downstream pipe meets the sampling flow requirement, the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer is obtained, and the aerosol concentration downstream of the gap test structure is calculated;
The control module calculates the retention efficiency of the aerosol in the gap test structure according to the calculated aerosol concentration at the upstream of the gap test structure and the calculated aerosol concentration at the downstream of the gap test structure.
Example 1:
the embodiment provides a device for measuring retention efficiency of aerosol in a gap, comprising:
a reaction vessel 1, a gap test structure 4, a gas equalizing structure, a particle diameter spectrometer 10 and a control module,
an upstream pipe and a downstream pipe are connected between the inlet end of the particle size spectrometer 10 and the reaction vessel 1, an upstream isolation valve is arranged on the upstream pipe, a downstream isolation valve 8 is arranged on the downstream pipe, the reaction vessel 1 is used for simulating the environment in the containment so as to output the gas in the upstream pipe or the downstream pipe, the particle size spectrometer 10 is used for detecting the concentration of aerosol in the gas entering the upstream pipe or the downstream pipe,
the gap test structure 4 and the gas equalizing structure are arranged on the downstream pipe, the gap test structure 4 is used for simulating the gap environment of the containment vessel so as to retain part of aerosol in the gas flowing through the gap test structure, the gas equalizing structure is used for supplementing air into the downstream pipe or exhausting part of gas in the downstream pipe,
the control module is respectively connected with the upstream isolation valve, the downstream isolation valve 8, the gas equalizing structure and the particle size spectrometer 10, and is used for controlling the opening of the upstream isolation valve so as to enable the gas entering the particle size spectrometer 10 from the upstream pipe to meet the sampling flow requirement, acquiring the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer 10 and calculating the aerosol concentration at the upstream of the gap test structure 4;
The control module is also used for controlling the closing of the upstream isolation valve and the opening of the downstream isolation valve 8, controlling the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas discharged from the interior of the downstream pipe so that the gas entering the particle size spectrometer 10 from the downstream pipe meets the sampling flow requirement, acquiring the concentration of the aerosol in the gas entering the downstream pipe detected by the particle size spectrometer 10 and calculating the concentration of the aerosol at the downstream of the gap test structure 4;
the control module is further configured to calculate a retention efficiency of the aerosol in the slit test structure 4 based on the calculated aerosol concentration upstream of the slit test structure 4 and the calculated aerosol concentration downstream of the slit test structure 4.
The pipeline is led out to the particle size spectrometer at the upstream and downstream of the gap test structure 4 respectively, and the downstream is provided with the gas equalizing structure to supplement air into the downstream pipe or discharge gas in the downstream pipe, so that the gas entering the particle size spectrometer from the downstream pipe meets the sampling flow requirement, and the concentration of the aerosol at the upstream and downstream of the gap test structure is directly measured by the particle size spectrometer. On the one hand, compared with the upstream sampling port arranged in the reaction container, the method reduces errors caused by uneven spatial distribution of the concentration of the upstream aerosol; on the other hand, compared with the method for measuring the concentration of the aerosol at the upstream and downstream of the gap test structure by using two particle size spectrometers, the method avoids the measurement error between different particle size spectrometers.
In this embodiment, the condensing and drying structure and the flowmeter 13 are also included,
the outlet end of the particle size spectrometer 10 is connected with a post-treatment pipe, the condensation drying structure and the flowmeter 13 are arranged on the post-treatment pipe and are sequentially arranged along the air flow direction, the condensation drying structure is used for condensing and removing steam in the air entering the condensation drying structure, and the flowmeter 13 is used for measuring the flow of the air flowing through the condensation drying structure;
the control module is also connected to the flow meter 13,
the control module comprises an upstream pre-processing unit and an upstream post-processing unit which are electrically connected,
the control module controls the opening of the upstream isolation valve to enable the gas entering the particle size spectrometer 10 from the upstream pipe to meet the sampling flow requirement, obtains the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer 10 and calculates the aerosol concentration at the upstream of the gap test structure 4, and specifically comprises the following steps:
when the upstream preprocessing unit calculates that the gas flow entering the particle size spectrometer 10 from the upstream pipe is the sampling flow of the particle size spectrometer 10, the flow q flowing through the flowmeter 13 c ，
The upstream post-processing unit controls the opening of the upstream isolation valve and controls the opening thereof so as to maintain the flow rate of the flowmeter 13 at q c Acquiring the aerosol concentration C in the gas into which the upstream tube enters detected by the particle size spectrometer 10 readin And according to C readin Calculating the aerosol concentration upstream of the gap test structure 4;
the control module also comprises a downstream preprocessing unit, a judging unit and a downstream post-processing unit which are electrically connected in sequence,
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve 8 to be opened, and controls the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas discharged from the interior of the downstream pipe, so that the gas entering the particle size spectrometer 10 from the downstream pipe meets the sampling flow requirement, and the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer 10 is obtained and calculated, and the method specifically comprises the following steps:
the downstream pretreatment unit controls the downstream isolation valve 8 to be opened and controls the gas equalizing structure to be closed, and obtains the flow q flowing through the flowmeter 13 no And according to q no Calculating the gas flow q of the downstream tube into the particle spectrometer 10 1 ，
The judging unit judges q 1 And the magnitude of the sampling flow rate of the particle size spectrometer 10,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer 10 is smaller, the air flow rate q required to be supplemented for the air homogenizing structure is calculated c1 Controlling the opening of the gas equalizing structure and controlling the feeding flow of the gas equalizing structure to the downstream pipe to be q c1 Acquiring the aerosol concentration in the gas entering the downstream tube detected by the particle size spectrometer 10C readout And according to C readout The aerosol concentration downstream of the gap test structure 4 was calculated,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer 10 is not less than the sampling flow rate, the gas equalizing structure is controlled to be opened so as to discharge partial gas in the downstream pipe, and the flow rate to the flowmeter 13 is maintained at q c Acquiring the aerosol concentration C in the gas entering the downstream tube detected by the particle size spectrometer 10 readout And according to C readout Calculating the aerosol concentration downstream of the gap test structure 4;
the control module further comprises a calculation unit, the calculation unit is respectively and electrically connected with the upstream post-processing unit and the downstream post-processing unit, and the calculation unit calculates the retention efficiency of the aerosol in the gap test structure 4 according to the calculated aerosol concentration at the upstream of the gap test structure 4 and the calculated aerosol concentration at the downstream of the gap test structure 4.
Under the severe accident condition of the nuclear power plant, the environmental conditions of the aerosol in the containment are high temperature, high pressure and high humidity, wherein the high temperature and the high pressure influence the parameters such as the concentration of the aerosol, and the high humidity environment is a challenge for the normal operation of the optical particle size spectrometer. When the gas condition is a mixture of air and steam, even if the heat preservation is good enough, the steam is not condensed, and because the aerosol optical particle size spectrometer defaults to the gas medium being air, the optical particle size spectrometer cannot accurately control the gas flow through the probe to be the sampling flow.
In this embodiment, by providing a post-treatment tube at the rear end of the particle size spectrometer 10, on which a condensation drying structure and a flow meter 13 are provided, the high-temperature and high-pressure mixed gas (air+steam) flowing out of the reaction vessel 1 flows through the probe of the particle size spectrometer 10 via an upstream tube or a downstream tube, and then enters the condensation drying structure to condense and remove the water vapor. Then the flow meter 13 is connected, and the flow of the flow meter 13 is controlled by the law of mass conservation, and the actual flow which is reversely pushed to the probe of the particle size spectrometer 10 is just the sampling requirement of the particle size spectrometer 10. Thus solving the problem of aerosol concentration measurement of the aerosol optical particle size spectrometer under the condition of non-pure air and under the condition of high temperature and high pressure measurement.
In addition, the upstream isolation valve includes a first valve 3 and a second valve 14, in this embodiment, the post-treatment pipe belongs to an extension pipe of the upstream pipe, the first valve 3 is disposed on the upstream pipe, the second valve 14 is disposed on the post-treatment pipe, and the control module controls the upstream isolation valve to open and control the opening thereof, specifically: the first valve 3 is controlled to be fully opened, and the opening of the second valve 14 is controlled so that the gas entering the particle size spectrometer 10 from the upstream pipe meets the sampling flow requirement.
As shown in fig. 1, the air equalizing structure comprises an air collecting cavity 7 arranged on the downstream pipe, and an air collecting pipe connected with the air collecting cavity, wherein the air collecting pipe is provided with an air collecting valve 5 and an air collecting flowmeter 5, when the downstream pipe needs air supplementing, the air collecting pipe is connected with an air source (not shown in the figure), the air source supplements air to the downstream pipe through the air equalizing structure, and when the downstream pipe needs air exhausting, the air collecting valve 5 is opened and the opening degree of the air collecting valve is controlled so as to exhaust part of air flowing through the downstream pipe.
In addition, the front ends of the upstream pipe and the downstream pipe along the airflow direction are connected with a front main pipe section, a main valve 2 is arranged on the front main pipe section, and the main valve 2 is used for isolating the test section and the reaction vessel 1.
The rear ends of the upstream pipe and the downstream pipe along the airflow direction are connected with a rear main pipe section, a pressure sensor 9 is arranged on the rear main pipe section, and the pressure sensor 9 is used for detecting the pressure of the gas entering the particle size spectrometer 10.
In this embodiment, temperature control mechanisms are respectively disposed on the upstream pipe and the downstream pipe, and each temperature control mechanism comprises an electric tracing band, heat insulation cotton and a PID temperature controller, and is used for controlling the temperature of the corresponding pipeline to be slightly higher than the temperature of the reaction vessel (generally not more than 5 degrees) so as to prevent steam in the pipeline from condensing.
In this embodiment, when the upstream preprocessing unit calculates that the flow rate of the gas entering the particle size spectrometer 10 from the upstream pipe is the sampling flow rate of the particle size spectrometer 10 by using the formula (1), the flow rate q flowing through the flowmeter 13 c ：
q c ＝ρ t2, / sensor ρ t1, (1f s1 ))(1)
Wherein ρ is t1, Is the density, mg/L, of the gas entering the particle size spectrometer 10 from the upstream tube, which enters the particle size spectrometer10 is p1, and the temperature is t1;
f s1 the volume fraction of water vapor in the gas entering the particle size spectrometer 10 for the upstream tube;
ρ t2，p2 the air with pressure p2 and temperature t2 is formed by condensing and drying the air entering the particle size spectrometer 10 from the upstream pipe, and mg/L is obtained.
In this embodiment, the downstream preprocessing unit acquires the flow q flowing through the flowmeter 13 no And according to q no Calculating the gas flow q of the downstream tube into the particle spectrometer 10 1 The calculation formula of (2) is shown as the formula:
q 1 ρ t3，p3 (1-f s2 )＝q no ρ t4，p4 (2)
wherein ρ is t3，p3 The density of the gas entering the particle size spectrometer 10 from the downstream pipe is mg/L under the condition that the gas homogenizing structure is closed, wherein the pressure of the gas entering the particle size spectrometer 10 from the downstream pipe is p3 and the temperature is t3;
f s2 the volume fraction of water vapor in the gas entering the particle size spectrometer 10 from the downstream pipe under the condition of closing the gas equalizing structure;
ρ t4，p4 in order to realize the closing working condition of the gas homogenizing structure, the pressure formed by condensing and drying the gas entering the particle size spectrometer 10 from the downstream pipe is p4, and the density of the air with the temperature of t4 is mg/L.
In this embodiment, the upstream post-processing unit detects the aerosol concentration C in the gas entering the upstream tube from the particle size spectrometer 10 readin Calculation of aerosol concentration C upstream of gap test structure 4 in The formula of (2) is shown as formula (3):
C in ＝C readlin p in /p 1 (3)
wherein p is in The pressure of the gas in the reaction vessel 1, bar;
p 1 the pressure of the gas entering the particle size spectrometer 10 at the upstream tube, bar.
In the present embodiment, the downstream post-processing unit determines q at the determination unit 1 < sampling of particle size spectrometer 10 When the flow is, the formula (4) is adopted to calculate the air flow q which needs to be supplemented for the air homogenizing structure c1 ：
q c1 ＝(q sensor -q 1 )ρ t5，p5 /ρ t6，p6 (4)
Wherein ρ is t5，p5 The density of the gas entering the particle size spectrometer 10 from the downstream pipe is mg/L under the gas filling working condition of the gas filling structure, wherein the pressure of the gas entering the particle size spectrometer 10 from the downstream pipe under the gas filling of the gas filling structure is p3, and the temperature is t3;
ρ t6，p6 under the condition of air supplementing of the air homogenizing structure, the pressure formed by condensing and drying the air entering the particle size spectrometer 10 from the downstream pipe is p6, and the density of the air with the temperature of t6 is mg/L.
In the present embodiment, the downstream post-processing unit determines q at the determination unit 1 When the sampling flow rate of the particle diameter spectrometer 10 is smaller, the aerosol concentration C in the gas entering the downstream pipe from the particle diameter spectrometer 10 is detected readout The formula for calculating the aerosol concentration downstream of the gap test structure 4 is shown in formula (5):
C out ＝C readout (p in /p 2 )q sensor /q 1 (5)
wherein p is 2 The pressure of the gas entering the particle size spectrometer 10 from the downstream pipe under the condition of supplementing the gas with the gas homogenizing structure, b ar 。
In the present embodiment, the downstream post-processing unit determines q at the determination unit 1 When the sampling flow rate of the particle size spectrometer 10 is not less than the sampling flow rate, the formula for calculating the aerosol concentration at the downstream of the gap test structure 4 according to the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer 10 is shown as formula (6):
C out ＝C readout (p in /p 3 ) (6)
Wherein p is 3 The pressure of the gas in the particle size spectrometer 10 is the pressure of the gas entering the downstream pipe under the exhaust working condition of the gas equalizing structure.
In this embodiment, the calculation unit calculates the retention efficiency P of the aerosol in the slit test structure 4 using the formula (7) based on the calculated aerosol concentration upstream of the slit test structure 4 and the calculated aerosol concentration downstream of the slit test structure 4:
P＝1-C out /C in (7)。
example 2:
this embodiment provides a method for measuring the retention efficiency of an aerosol in a gap using the apparatus of embodiment 1, comprising the steps of:
the control module controls the opening of the upstream isolation valve so that the gas entering the particle size spectrometer 10 from the upstream pipe meets the sampling flow requirement, acquires the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer 10 and calculates the aerosol concentration upstream of the gap test structure 4;
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve 8 to be opened, and controls the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas in the downstream pipe to be discharged, so that the gas entering the particle size spectrometer 10 by the downstream pipe meets the sampling flow requirement, the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer 10 is obtained, and the aerosol concentration downstream of the gap test structure 4 is calculated;
The control module calculates the retention efficiency of the aerosol in the gap test structure 4 according to the calculated aerosol concentration upstream of the gap test structure 4 and the calculated aerosol concentration downstream of the gap test structure 4.
In this embodiment, the outlet end of the particle size spectrometer 10 is connected to a post-treatment tube, the condensation drying structure and the flow meter 13 are disposed on the post-treatment tube and are sequentially disposed along the air flow direction, the condensation drying structure is used for condensing and removing steam in the air entering the condensation drying structure, and the flow meter 13 is used for measuring the flow rate of the air flowing through the condensation drying structure;
the control module is also connected to the flow meter 13,
the control module comprises an upstream pre-processing unit and an upstream post-processing unit which are electrically connected,
the control module controls the opening of the upstream isolation valve to enable the gas entering the particle size spectrometer 10 from the upstream pipe to meet the sampling flow requirement, obtains the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer 10 and calculates the aerosol concentration at the upstream of the gap test structure 4, and specifically comprises the following steps:
when the upstream preprocessing unit calculates that the gas flow entering the particle size spectrometer 10 from the upstream pipe is the sampling flow of the particle size spectrometer 10, the flow q flowing through the flowmeter 13 c ，
The upstream post-processing unit controls the opening of the upstream isolation valve and controls the opening thereof so as to maintain the flow rate of the flowmeter 13 at q c Acquiring the aerosol concentration C in the gas into which the upstream tube enters detected by the particle size spectrometer 10 readin And according to C readin Calculating the aerosol concentration upstream of the gap test structure 4;
the control module also comprises a downstream preprocessing unit, a judging unit and a downstream post-processing unit which are electrically connected in sequence,
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve 8 to be opened, and controls the flow of air fed into the downstream pipe by the air equalizing structure or the flow of gas discharged from the interior of the downstream pipe, so that the gas entering the particle size spectrometer 10 from the downstream pipe meets the sampling flow requirement, and the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer 10 is obtained and calculated, and the method specifically comprises the following steps:
the downstream pretreatment unit controls the downstream isolation valve 8 to be opened and controls the gas equalizing structure to be closed, and obtains the flow q flowing through the flowmeter 13 no And according to q no Calculating the gas flow q of the downstream tube into the particle spectrometer 10 1 ，
The judging unit judges q 1 And the magnitude of the sampling flow rate of the particle size spectrometer 10,
The downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer 10 is smaller, the air flow rate q required to be supplemented for the air homogenizing structure is calculated c1 Controlling the opening of the gas equalizing structure and controlling the feeding flow of the gas equalizing structure to the downstream pipe to be q c1 Acquiring the aerosol concentration C in the gas entering the downstream tube detected by the particle size spectrometer 10 readout And according to C readout Calculation of the gap testThe aerosol concentration downstream of the test structure 4,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer 10 is not less than the sampling flow rate, the gas equalizing structure is controlled to be opened so as to discharge partial gas in the downstream pipe, and the flow rate to the flowmeter 13 is maintained at q c Acquiring the aerosol concentration C in the gas entering the downstream tube detected by the particle size spectrometer 10 readout And according to C readout Calculating the aerosol concentration downstream of the gap test structure 4;
the control module further comprises a calculation unit which is respectively and electrically connected with the upstream post-processing unit and the downstream post-processing unit, and the calculation unit calculates the retention efficiency of the aerosol in the gap test structure 4 according to the calculated aerosol concentration at the upstream of the gap test structure 4 and the calculated aerosol concentration at the downstream of the gap test structure 4.
The following describes in detail, by way of a specific example, the specific procedure of the method for measuring the retention efficiency of aerosol in a slit according to the present embodiment:
Step one: and constructing a measuring loop for measuring the retention efficiency of the aerosol in the gap.
As shown in fig. 1, the device mainly comprises a reaction vessel 1, a main valve 2, an upstream isolation valve, a gap test structure 4, a gas collecting flow meter 5, a gas collecting valve 6, a gas collecting cavity 7, a downstream isolation 8, a pressure sensor 9, an aerosol particle size spectrometer 10, a cold dryer 11, a drying pipe 12, a flow meter 13 and a valve 14. Wherein the reaction vessel 1 is used for generating aerosol under specific pressure, temperature and humidity conditions; the main valve 2 is used for isolating the test section and the reaction vessel; the upstream isolation valve and the downstream isolation valve 8 are used for switching the upstream and the downstream of the gap test structure, and measuring the concentration of the aerosol at the upstream and the downstream respectively through the aerosol particle size spectrometer 10, wherein the measurement of the concentration at the upstream and the downstream of the gap test structure is completed through only 1 probe, so that the error between different probes is avoided; the gap test structure 4 is used for retaining aerosol; the air collecting valve 6 and the air collecting flowmeter 5 are used for controlling the air supplementing flow of the air collecting cavity 7; the gas collection cavity 7 is used for supplementing the flow of the gap test structure so as to meet the flow requirement (5L/min in the embodiment) of the probe of the aerosol optical particle size spectrometer 10; the pressure sensor 9 is used for measuring the gas pressure passing through the probe; the particle size spectrometer 10 is used for measuring the concentration of aerosol at the upstream and downstream of the gap test structure; the cold dryer 11 is used for condensing steam in the mixed gas; the drying pipe 12 is used for removing moisture from the mixture; the flow meter 13 and the valve 14 are used for flow control.
It should be noted that the temperature of the upstream pipe and the downstream pipe are controlled to be slightly higher than the temperature of the reaction vessel (generally not more than 5 degrees) by an electric tracing band, heat insulation cotton and a PID temperature controller to prevent the steam in the pipe from condensing.
Step two: the aerosol concentration upstream of the gap test structure was measured.
When the gas condition is a mixture of air and steam, even if the incubation is good enough, the steam does not condense, and since the aerosol optical particle size spectrometer defaults to air, the particle size spectrometer 10 cannot accurately control the gas flow through the probe to 5L/min. Here, the flow control function of the particle diameter spectrometer 10 needs to be omitted, and only the counting function is used. After flowing through the spectrometer probe, the fluid enters a cold dryer 11 and a drying pipe 12, and water vapor is condensed and removed. Then the flow meter 13 is connected, and the flow of the flow meter is controlled to be pushed back to the position of the probe to be just 5L/min. The principle adopted by the flow control is mass conservation, and the mass conservation is shown in the following formula.
q sensor ρ t1，p1 (1-f s1 )＝q c ρ t2，p2
It is possible to obtain a solution,
q c ＝ρ t2，p2 /(q sensor ρ t1，p1 (1-f s1 )) (1)
wherein q is c L/min is the flow of the flowmeter 13;
q sensor the sampling flow requirement of the probe is 5L/min;
ρ t1，p1 the density of the gas entering the particle size spectrometer 10 from the upstream pipe is mg/L, wherein the pressure of the gas entering the particle size spectrometer 10 from the upstream pipe is p1, and the temperature is t1;
f s1 The volume fraction of water vapor in the gas entering the particle size spectrometer 10 for the upstream tube;
ρ t2，p2 the air with pressure p2 and temperature t2 is formed by condensing and drying the air entering the particle size spectrometer 10 from the upstream pipe, and mg/L is obtained.
Actual aerosol concentration C upstream of the gap test structure 4 in Can be transformed by the following formula.
C in ＝C readin p in /p 1 (3)
Wherein C is readin The aerosol concentration in the gas into which the resulting upstream tube enters is detected for particle size spectrometer 10 (i.e., particle size spectrometer 10 shows the concentration);
p in the pressure of the gas in the reaction vessel 1, bar;
p 1 the pressure of the gas entering the particle size spectrometer 10 at the upstream tube, bar.
Step three: aerosol concentration downstream of the gap test structure was measured.
The measurement of the concentration of aerosol at the downstream of the capillary tube also needs to control the flow rate at the flow rate of the probe to be 5L/min, and under the condition of no air supplement, the air flow rate at the probe is reversely pushed by the air flow rates of the cold dryer 11 and the drying pipe 12, and if the air flow rate is smaller than 5L/min, the air supplement is needed to be carried out through an air supplement loop, and the air supplement flow rate is controlled through a flowmeter; if the flow rate is more than 5L/min, the air supplementing loop acts as a bypass, and the flow rate passing through the probe is controlled to be 5L/min through a valve of the bypass loop. The flow control is calculated as follows.
The downstream flow meter 13 reads q without make-up no According to q no Calculating the gas flow q of the downstream tube into the particle spectrometer 10 1 The calculation formula of (2) is shown as the formula:
q 1 ρ t3，p3 (1-f s2 )＝q no ρ t4，p4 (2)
wherein ρ is t3，p3 The density of the gas entering the particle size spectrometer 10 from the downstream pipe is mg/L under the condition that the gas homogenizing structure is closed, wherein the pressure of the gas entering the particle size spectrometer 10 from the downstream pipe is p3 and the temperature is t3;
f s2 downstream under the condition of closing the gas equalizing structureThe volume fraction of water vapor in the gas that the tube enters the particle size spectrometer 10;
ρ t4，p4 in order to realize the closing working condition of the gas homogenizing structure, the pressure formed by condensing and drying the gas entering the particle size spectrometer 10 from the downstream pipe is p4, and the density of the air with the temperature of t4 is mg/L.
Obtaining the gas flow q of the downstream pipe into the particle diameter spectrometer 10 according to the law of mass conservation 1 Then, judge q 1 Relationship with 5L/min.
1)q 1 ＜5L/min
Air flow q of air homogenizing structure to be supplemented c1 Can be obtained by the following formula.
q c1 ＝(q sensor -q 1 )ρ t5，p5 /ρ t6，p6 (4)
Wherein ρ is t5，p5 The density of the gas entering the particle size spectrometer 10 from the downstream pipe is mg/L under the gas filling working condition of the gas filling structure, wherein the pressure of the gas entering the particle size spectrometer 10 from the downstream pipe under the gas filling of the gas filling structure is p3, and the temperature is t3;
ρ t6，p6 under the condition of air supplementing of the air homogenizing structure, the pressure formed by condensing and drying the air entering the particle size spectrometer 10 from the downstream pipe is p6, and the density of the air with the temperature of t6 is mg/L.
At this time, the aerosol concentration C in the gas entering the downstream pipe from the particle diameter spectrometer 10 can be detected by the formula (5) readout Calculate aerosol concentration downstream of the gap test structure 4:
C out ＝C readout (p in /p 2 )q sensor /q 1 (5)
wherein p is 2 The pressure of the gas in the particle size spectrometer 10 is regulated by the downstream pipe under the condition of supplementing the gas with the gas homogenizing structure.
1)q 1 ≥5L/min
At this time, the air supplementing loop acts as a bypass loop, and the bypass flow is controlled through the air collecting flow meter 5 and the air collecting valve 6, so that the flow passing through the probe is 5L/min;
at this time, the aerosol concentration downstream of the slit test structure 4 may be calculated from the aerosol concentration in the gas into which the downstream tube enters detected by the particle diameter spectrometer 10 using the formula (6):
C out ＝C readout (p in /p 3 ) (6)
wherein p is 3 The pressure of the gas in the particle size spectrometer 10 is the pressure of the gas entering the downstream pipe under the exhaust working condition of the gas equalizing structure.
The aerosol retention efficiency P in the slit test piece can be obtained by the following formula.
P＝1-C out /C in (7)。
It is to be understood that the above embodiments are merely illustrative of the application of the principles of the present invention, but not in limitation thereof. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the invention, and are also considered to be within the scope of the invention.

Claims (12)

1. An apparatus for measuring aerosol retention efficiency in a gap, comprising:
a reaction vessel (1), a gap test structure (4), a gas equalizing structure, a particle size spectrometer (10) and a control module,
an upstream pipe and a downstream pipe are connected between the inlet end of the particle size spectrometer (10) and the reaction vessel (1), an upstream isolation valve is arranged on the upstream pipe, a downstream isolation valve (8) is arranged on the downstream pipe, the reaction vessel (1) is used for simulating the environment in the containment so as to output the gas in the upstream pipe or the downstream pipe, the particle size spectrometer (10) is used for detecting the concentration of aerosol in the gas entering the upstream pipe or the downstream pipe,
the gap test structure (4) and the gas-equalizing structure are arranged on the downstream pipe, the gap test structure (4) is used for simulating the gap environment of the containment vessel so as to retain part of aerosol in the gas flowing through the gap test structure, the gas-equalizing structure is used for supplementing air into the downstream pipe or exhausting part of gas in the downstream pipe,
the control module is respectively connected with the upstream isolation valve, the downstream isolation valve (8), the gas equalizing structure and the particle size spectrometer (10), and is used for controlling the opening of the upstream isolation valve so as to enable gas entering the particle size spectrometer (10) from an upstream pipe to meet the sampling flow requirement, acquiring the concentration of aerosol in the gas entering the upstream pipe detected by the particle size spectrometer (10) and calculating the concentration of aerosol at the upstream of the gap test structure (4);
The control module is also used for controlling the closing of the upstream isolation valve and the opening of the downstream isolation valve (8), controlling the flow of air fed into the downstream pipe by the air equalizing structure or the flow of partial gas discharged from the downstream pipe so that the gas entering the particle size spectrometer (10) from the downstream pipe meets the sampling flow requirement, acquiring the concentration of the aerosol in the gas entering the downstream pipe detected by the particle size spectrometer (10) and calculating the concentration of the aerosol at the downstream of the gap test structure (4);
the control module is also used for calculating the retention efficiency of the aerosol in the gap test structure (4) according to the calculated aerosol concentration at the upstream of the gap test structure (4) and the calculated aerosol concentration at the downstream of the gap test structure (4).
2. The device for measuring the efficiency of aerosol retention in a gap according to claim 1, further comprising a condensation drying structure and a flow meter (13),
the outlet end of the particle size spectrometer (10) is connected with a post-treatment pipe, the condensation drying structure and the flowmeter (13) are arranged on the post-treatment pipe and are sequentially arranged along the air flow direction, the condensation drying structure is used for condensing and removing steam in the air entering the condensation drying structure, and the flowmeter (13) is used for measuring the flow of the air flowing through the condensation drying structure;
The control module is also connected with the flowmeter (13),
the control module comprises an upstream pre-processing unit and an upstream post-processing unit which are electrically connected,
the control module controls the opening of the upstream isolation valve to enable gas entering the particle size spectrometer (10) from the upstream pipe to meet the sampling flow requirement, obtains the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer (10) and calculates the aerosol concentration at the upstream of the gap test structure (4), and specifically comprises the following steps:
when the upstream preprocessing unit calculates that the gas flow entering the particle size spectrometer (10) from the upstream pipe is the sampling flow of the particle size spectrometer (10), the flow q flowing through the flowmeter (13) c ，
The upstream aftertreatment unit controls the opening of the upstream isolation valve and controls the opening thereof so as to maintain the flow rate of the flowmeter (13) at q c Acquiring the aerosol concentration C in the gas entering the upstream pipe detected by a particle size spectrometer (10) readin And according to C readin Calculating an aerosol concentration upstream of the gap test structure (4);
the control module also comprises a downstream preprocessing unit, a judging unit and a downstream post-processing unit which are electrically connected in sequence,
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve (8) to be opened, and controls the flow of air fed into the downstream pipe by the air equalizing structure or the flow of partial gas discharged from the downstream pipe, so that the gas entering the particle size spectrometer (10) by the downstream pipe meets the sampling flow requirement, the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer (10) is obtained, and the aerosol concentration downstream of the gap test structure (4) is calculated, and the control module specifically comprises:
The downstream pretreatment unit controls the downstream isolation valve (8) to be opened and controls the gas equalizing structure to be closed, and obtains the flow q flowing through the flowmeter (13) no And according to q no Calculating the gas flow q of the downstream pipe entering the particle size spectrometer (10) 1 ，
The judging unit judges q 1 And the magnitude relation of the sampling flow rate of the particle size spectrometer (10),
the downstream post-processing unit judges q at the judging unit 1 <When the sampling flow of the particle size spectrometer (10) is used, the air flow q of the air-homogenizing structure to be supplemented is calculated c1 Controlling the opening of the gas equalizing structure and controlling the feeding flow of the gas equalizing structure to the downstream pipe to be q c1 Acquiring the aerosol concentration C in the gas entering the downstream pipe detected by a particle size spectrometer (10) readout And according to C readout Calculating the aerosol concentration downstream of the gap test structure (4),
downstream aftertreatment unit inThe judging unit judges q 1 When the sampling flow rate of the particle size spectrometer (10) is not less than the sampling flow rate, the gas equalizing structure is controlled to be opened so as to discharge gas in the downstream pipe, and the flow rate to the flowmeter (13) is maintained at q c Acquiring the aerosol concentration C in the gas entering the downstream pipe detected by a particle size spectrometer (10) readout And according to C readout Calculating an aerosol concentration downstream of the gap test structure (4);
the control module further comprises a calculation unit which is respectively and electrically connected with the upstream post-processing unit and the downstream post-processing unit, and the calculation unit calculates the retention efficiency of the aerosol in the gap test structure (4) according to the calculated aerosol concentration at the upstream of the gap test structure (4) and the calculated aerosol concentration at the downstream of the gap test structure (4).
3. The apparatus for measuring the retention efficiency of an aerosol in a slit according to claim 2, wherein,
when the upstream preprocessing unit calculates that the gas flow entering the particle size spectrometer (10) from the upstream pipe is the sampling flow of the particle size spectrometer (10) by adopting the formula (1), the flow q flowing through the flowmeter (13) c ：
q c ＝ρ t2，p2 /(q sensor ρ t1，p1 (1-f s1 )) (1)
Wherein ρ is t1，p1 The density of the gas entering the particle size spectrometer (10) from the upstream pipe is mg/L, wherein the pressure of the gas entering the particle size spectrometer (10) from the upstream pipe is p1, and the temperature is t1;
f s1 the volume fraction of water vapor in the gas entering the particle size spectrometer (10) for the upstream tube;
ρ t2，p2 the air with the pressure p2 and the temperature t2 is formed by condensing and drying the air entering the particle size spectrometer (10) from the upstream pipe, and the density is mg/L.
4. An apparatus for measuring the efficiency of aerosol retention in a gap according to claim 2, characterized in that a downstream pre-processing unit obtains the flow q through the flow meter (13) no And according to q no Calculating downstream pipe feedGas flow rate q into particle size spectrometer (10) 1 The calculation formula of (2) is shown as the formula:
q 1 ρ t3，p3 (1-f s2 )＝q no ρ t4，p4 (2)
wherein ρ is t3，p3 The density of the gas entering the particle size spectrometer (10) from the downstream pipe is mg/L under the condition that the gas homogenizing structure is closed, wherein the pressure of the gas entering the particle size spectrometer (10) from the downstream pipe is p3 and the temperature is t3;
f s2 The volume fraction of water vapor in the gas entering the particle size spectrometer (10) from the downstream pipe under the condition of closing the gas homogenizing structure;
ρ t4，p4 in order to realize the closing working condition of the gas homogenizing structure, the pressure formed by condensing and drying the gas entering the particle size spectrometer (10) from the downstream pipe is p4, and the density of the air with the temperature of t4 is mg/L.
5. The apparatus for measuring the retention efficiency of an aerosol in a slit according to claim 2, wherein,
the upstream post-processing unit detects the aerosol concentration C in the gas entering the upstream pipe according to the particle size spectrometer (10) readin Calculation of aerosol concentration C upstream of the gap test Structure (4) i The formula of n is shown in formula (3):
C in ＝C readin p in /p 1 (3)
wherein p is in The pressure of the gas in the reaction vessel (1), bar;
p 1 the pressure of the gas entering the particle size spectrometer (10) at the upstream tube, bar.
6. The apparatus for measuring the retention efficiency of an aerosol in a slit according to claim 2, wherein,
the downstream post-processing unit judges q at the judging unit 1 <When the particle size spectrometer (10) samples the flow, the formula (4) is adopted to calculate the air flow q which needs to be supplemented for the air-homogenizing structure c1 ：
q c1 ＝(q sensor -q 1 )ρ t5，p5 /ρ t6，p6 (4)
Wherein ρ is t5，p5 The density of the gas entering the particle size spectrometer (10) from the downstream pipe is mg/L under the gas supplementing working condition of the gas homogenizing structure, wherein the pressure of the gas entering the particle size spectrometer (10) from the downstream pipe is p3 and the temperature is t3;
ρ t6，p6 Under the air-supplementing working condition of the air-homogenizing structure, the pressure formed by condensing and drying the air entering the particle size spectrometer (10) from the downstream pipe is p6, and the density of the air with the temperature of t6 is mg/L.
7. The apparatus for measuring in-slit aerosol retention efficiency as set forth in claim 2, wherein the downstream post-processing unit determines q at the determination unit 1 <When the particle size spectrometer (10) samples the flow, the aerosol concentration C in the gas entering the downstream pipe according to the particle size spectrometer (10) detection readout The formula for calculating the aerosol concentration downstream of the gap test structure (4) is shown in formula (5):
C out ＝C readout (p in /p 2 )q sensor /q 1 (5)
wherein p is 2 And (3) the pressure of the gas in the particle size spectrometer (10) is fed into the downstream pipe under the gas-filling working condition of the gas-equalizing structure, and the pressure is bar.
8. The apparatus for measuring the retention efficiency of an aerosol in a slit according to claim 2, wherein,
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer (10) is not less than, the formula for calculating the aerosol concentration at the downstream of the gap test structure (4) according to the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer (10) is shown as formula (6):
C out ＝C readout (p in /p 3 ) (6)
wherein p is 3 The pressure of the gas in the particle size spectrometer (10) is introduced into the downstream pipe under the exhaust working condition of the gas equalizing structure, and the pressure is bar.
9. The apparatus for measuring in-slit aerosol retention efficiency according to claim 2, wherein the calculation unit calculates the retention efficiency P of the aerosol in the slit test structure (4) using formula (7) based on the calculated aerosol concentration upstream of the slit test structure (4) and the calculated aerosol concentration downstream of the slit test structure (4):
P＝1-C out /C in (7)。
10. device for measuring the efficiency of aerosol retention in a gap according to any of claims 1 to 9, characterized in that temperature control means are provided on both the upstream and downstream pipes for controlling the temperature of the respective pipe slightly above the temperature of the reaction vessel (1).
11. A method of measuring the efficiency of aerosol retention in a gap using a device according to any one of claims 1 to 10, comprising the steps of:
the control module controls the opening of the upstream isolation valve so that the gas entering the particle size spectrometer (10) from the upstream pipe meets the sampling flow requirement, acquires the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer (10) and calculates the aerosol concentration upstream of the gap test structure (4);
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve (8) to be opened, and controls the flow of air fed into the downstream pipe or the flow of gas discharged from the interior of the downstream pipe by the gas equalizing structure, so that the gas entering the particle size spectrometer (10) from the downstream pipe meets the sampling flow requirement, the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer (10) is obtained, and the aerosol concentration downstream of the gap test structure (4) is calculated;
The control module calculates the retention efficiency of the aerosol in the gap test structure (4) according to the calculated aerosol concentration at the upstream of the gap test structure (4) and the calculated aerosol concentration at the downstream of the gap test structure (4).
12. The method for measuring aerosol retention efficiency in a gap of claim 11,
the outlet end of the particle size spectrometer (10) is connected with a post-treatment pipe, the condensation drying structure and the flowmeter (13) are arranged on the post-treatment pipe and are sequentially arranged along the air flow direction, the condensation drying structure is used for condensing and removing steam in the air entering the condensation drying structure, and the flowmeter (13) is used for measuring the flow of the air flowing through the condensation drying structure;
the control module is also connected with the flowmeter (13),
the control module comprises an upstream pre-processing unit and an upstream post-processing unit which are electrically connected,
the control module controls the opening of the upstream isolation valve to enable gas entering the particle size spectrometer (10) from the upstream pipe to meet the sampling flow requirement, obtains the aerosol concentration in the gas entering the upstream pipe detected by the particle size spectrometer (10) and calculates the aerosol concentration at the upstream of the gap test structure (4), and specifically comprises the following steps:
when the upstream preprocessing unit calculates that the gas flow entering the particle size spectrometer (10) from the upstream pipe is the sampling flow of the particle size spectrometer (10), the flow q flowing through the flowmeter (13) c ，
The upstream aftertreatment unit controls the opening of the upstream isolation valve and controls the opening thereof so as to maintain the flow rate of the flowmeter (13) at q c Acquiring the aerosol concentration C in the gas entering the upstream pipe detected by a particle size spectrometer (10) readin And according to C readin Calculating an aerosol concentration upstream of the gap test structure (4);
the control module also comprises a downstream preprocessing unit, a judging unit and a downstream post-processing unit which are electrically connected in sequence,
the control module controls the upstream isolation valve to be closed and controls the downstream isolation valve (8) to be opened, and controls the flow of air fed into the downstream pipe by the air equalizing structure or the flow of partial gas discharged from the downstream pipe, so that the gas entering the particle size spectrometer (10) by the downstream pipe meets the sampling flow requirement, the aerosol concentration in the gas entering the downstream pipe detected by the particle size spectrometer (10) is obtained, and the aerosol concentration downstream of the gap test structure (4) is calculated, and the control module specifically comprises:
the downstream pretreatment unit controls the downstream isolation valve (8) to be opened and controls the gas equalizing structure to be closed, and obtains the flow q flowing through the flowmeter (13) no And according to q no Calculating the gas flow q of the downstream pipe entering the particle size spectrometer (10) 1 ，
The judging unit judges q 1 And the magnitude relation of the sampling flow rate of the particle size spectrometer (10),
The downstream post-processing unit judges q at the judging unit 1 <When the sampling flow of the particle size spectrometer (10) is used, the air flow q of the air-homogenizing structure to be supplemented is calculated c1 Controlling the opening of the gas equalizing structure and controlling the feeding flow of the gas equalizing structure to the downstream pipe to be q c1 Acquiring the aerosol concentration C in the gas entering the downstream pipe detected by a particle size spectrometer (10) readout And according to C readout Calculating the aerosol concentration downstream of the gap test structure (4),
the downstream post-processing unit judges q at the judging unit 1 When the sampling flow rate of the particle size spectrometer (10) is not less than the sampling flow rate, the gas equalizing structure is controlled to be opened so as to discharge gas in the downstream pipe, and the flow rate to the flowmeter (13) is maintained at q c Acquiring the aerosol concentration C in the gas entering the downstream pipe detected by a particle size spectrometer (10) readout And according to C readout Calculating an aerosol concentration downstream of the gap test structure (4);
the control module further comprises a calculation unit which is respectively and electrically connected with the upstream post-processing unit and the downstream post-processing unit, and the calculation unit calculates the retention efficiency of the aerosol in the gap test structure (4) according to the calculated aerosol concentration at the upstream of the gap test structure (4) and the calculated aerosol concentration at the downstream of the gap test structure (4).
CN202310286631.3A 2023-03-22 2023-03-22 Device and method for measuring retention efficiency of aerosol in gap Pending CN116499936A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310286631.3A CN116499936A (en) 2023-03-22 2023-03-22 Device and method for measuring retention efficiency of aerosol in gap

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310286631.3A CN116499936A (en) 2023-03-22 2023-03-22 Device and method for measuring retention efficiency of aerosol in gap

Publications (1)

Publication Number Publication Date
CN116499936A true CN116499936A (en) 2023-07-28

Family

ID=87320887

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310286631.3A Pending CN116499936A (en) 2023-03-22 2023-03-22 Device and method for measuring retention efficiency of aerosol in gap

Country Status (1)

Country Link
CN (1) CN116499936A (en)

Similar Documents

Publication Publication Date Title
JP6411464B2 (en) Emission monitoring system for vent system of nuclear power plant
JP5492001B2 (en) Exhaust gas analysis system
US7647811B2 (en) Solid particle counting system with valve to allow reduction of pressure pulse at particle counter when vacuum pump is started
CN108507918B (en) Device and method for on-line monitoring concentration of ultralow-emission flue gas particles
CN108827821B (en) Device and method for rapidly analyzing hydrogen concentration in nuclear power station containment
CN109855924B (en) On-line detection system for severe environment aerosol
CN209878413U (en) Atmospheric aerosol on-line trapping and chemical component detection device
CN110308216A (en) The integrated analysis system and its application method of micro permanent foreign gas and water in a kind of gas
US6615678B2 (en) Exhaust gas sampling device
CN109946123A (en) A kind of atmospheric aerosol traps online and the method and apparatus of chemical component detection
CN104364630A (en) Exhaust gas dilution device
US7665375B2 (en) Flow splitter for a solid particle counting system
CN105004801A (en) Loop heat pipe ammonia working medium purity analysis device
EP3085914B1 (en) Exhaust gas measurement system
CN108414299A (en) A kind of stationary source exhaust gas sampling apparatus and the method for sampling
CN104122374B (en) The verification method of a kind of sulphur trioxide sampling test macro and device
CN116499936A (en) Device and method for measuring retention efficiency of aerosol in gap
JP4452801B2 (en) Gas sampling method and apparatus
CN113959792A (en) Device and method for measuring mercury in flue gas based on low-temperature plasma pyrolysis
CN203658337U (en) Multifunctional gas analyzer for livestock and poultry
CN207301017U (en) The continuous on-line detection device of sulfur trioxide in a kind of flue gas
CZ282516B6 (en) Apparatus for monitoring atmosphere inside a nuclear plant safety tank
CN114184709B (en) Chlorosilane on-line detection device and method
CN114608898A (en) Flue gas multi-component measurement system and use method
CN207528518U (en) A kind of lasting collector of chemical method the escaping of ammonia in-line analyzer

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination