RU2802163C1 - Gas control device - Google Patents

Abstract

FIELD: analytical instrumentation.

SUBSTANCE: portable small-sized and autonomous devices for gas analysis, used when carrying out research on gas release in sealed containers and enclosed spaces. The gas control device contains an analog-to-digital converter, a microcontroller, a power supply module, sensors for hydrogen, oxygen, pressure, as well as temperature and humidity, and a PC with the ability to connect to the microcontroller. The device according to the invention contains a non-volatile memory connected to the microcontroller, a real-time clock and a power control unit, which is connected to the power supply module, while the oxygen and hydrogen sensors are connected through conversion elements to an analog-to-digital converter, which is connected to the microcontroller connected to the pressure sensors, temperature and humidity. Holes are made in the body of the device, opposite which the sensors are located.

EFFECT: possibility of simultaneous measurement of temperature, humidity, pressure and composition of the measured multicomponent gaseous medium in hermetic volumes without changing its composition.

1 cl, 2 dwg

Description

The invention relates to analytical instrumentation, in particular, to portable small-sized and stand-alone devices for gas analysis and can be used in studies of gas release in sealed containers and enclosed spaces. It can also find application in gas analytical systems and be used in all industries for the simultaneous measurement of the main parameters of gaseous media and volume fractions of components (for example, hydrogen, oxygen).

Known gas analyzer for analyzing the composition of gas mixtures (RF patent No. 2274855, IPC G01N 27/416, publ. 20.04.2006). The gas analyzer includes a homogenizer, measuring cells with a measuring sensor installed in each of them, and each different measuring cell has a measuring non-selective sensor of a different physical principle of operation, having a linear characteristic or a non-linear characteristic linearized in the area of the intended control of the magnitudes of electrical signals, each of which has eliminated influence on each other in electric and pneumatic circuits. The outputs of the measuring sensors are connected to an electronic unit for processing the measured voltages and determining the informative parameters of the gas mixture.

The electronic unit for processing the measured voltages and determining the informative parameters of the gas mixture is a microprocessor unit, in whose memory the calibration functions obtained on gas mixtures of known composition are stored, which is a well-known and widely used technical solution in the technique of analyzing the composition of multicomponent gas mixtures.

The gas mixtures selected for analysis are passed through the measuring cells, using in each different cell a measuring non-selective sensor of a different physical principle of operation, having a linear or non-linear characteristic, linearized in the area of the intended control of the magnitudes of electrical signals. The number of sensors is at least not less than the number of gas mixture components, and the concentration values of the gas mixture components are determined on the basis of pre-known qualitative compositions of gas mixtures from the measured values of the electrical signals of the measuring sensors and the sensitivities of the measuring sensors determined by the calibration functions relative to each specific component of the gas mixture as a result of solving a system of linear equations relating the values of electrical signals, sensor sensitivities relative to a specific component of the gas mixture and concentrations, and before passing the gas mixtures into the measuring cells, they are homogenized.

This solution allows quite simply using a small number of measuring sensors to analyze gas mixtures, which may include a large number of components. However, this gas analyzer does not have the ability to remotely process the results.

A hydrogen gas analyzer is known (RF patent No. 2371710, IPC G01N 27/14, publ. 27.10.2009), containing a sensor chamber configured to be connected to a controlled volume. The sensor chamber contains a sensor and a porous or diffusion membrane wall selective to hydrogen, the sensor chamber is filled with a hydrogen-sensitive substance with an exothermic response, the sensor is made in the form of at least one thermocouple or thermistor. The membrane wall is made of impact-resistant material. The sensor chamber is equipped with a sealed cartridge with a mounting bracket for attaching it to the controlled volume. This gas analyzer is reliable, simple and quite cheap, while it has a long service life.

However:

- the use of an exothermic method for determining the concentration of hydrogen leads to a change in the temperature of the gaseous medium;

- does not allow measuring the pressure and humidity of the gaseous medium;

- does not allow measuring the oxygen concentration of the gaseous medium;

- does not save the received data to the internal memory of the gas analyzer.

A gas analyzer is known (RF patent No. 84563, IPC G01N 27/416, publ. 07/10/2009), containing a removable sensor module, including a series-connected sensing element, a device for pre-processing an analog signal, an amplifier, an analog-to-digital converter and a microcontroller, a secondary device , which includes a microprocessor that reads information from the output of the sensor module. The sensor module and the secondary device are made with the possibility of interconnection through connectors by inserting into each other. A block of non-volatile memory is introduced into the removable sensor module, connected to the microcontroller of the sensor module and containing data on all passport and calibration parameters of the sensor module, as well as on the threshold concentrations of the measured gas. The sensor module amplifier is made in the form of an amplifier with a variable gain, and the analog-to-digital converter of the module is made in the form of an analog-to-digital converter with a variable bit depth. The amplifier and analog-to-digital converter are connected to the microcontroller of the sensor module via feedback.

This gas analyzer provides a simple change from one type of sensing element to another type of sensing element by automatically adjusting the parameters of the elements of the sensor module.

However, this gas analyzer:

- does not allow measuring the pressure, humidity of the gaseous medium;

- not suitable for use in hermetic volumes with a small free volume;

- does not allow measurement of two gases at the same time.

The closest analogue of the claimed invention, selected as a prototype, is a device for analyzing a multicomponent gaseous environment of sealed containers with electronic devices, known from RF No. 2528273, IPC G01N 27/416, publ. 09/10/2014. The device contains an analytical unit (analog-to-digital converter), a control unit (microcontroller), a battery power supply unit (power supply module), selective and non-selective sensors for gas components, a pressure sensor, as well as a temperature and humidity sensor and a PC that is connected to the control unit (microcontroller ).

The device also contains a sampling device, a gas analyzer with a measuring cell equipped with sensors that record the parameters of the analyzed multicomponent gaseous medium of sealed containers. Additionally, a replaceable transition element is installed in the sealed container, one part of which has a constant cross section and is fitted to the inlet fitting of the sampling device, and the opposite part, made with a counterpart corresponding to the cross section of the check valve fitting of any of the analyzed sealed containers, is fitted to the fitting of the container check valve , a replaceable transition element, a portable gas analyzer, a gas analyzer measuring cell with measuring sensors constitute a single pneumatic circuit with a sampling device. The measuring cell is equipped with selective and non-selective sensors for measuring the content of the components of the analyzed gaseous medium and, additionally, with selective sensors for measuring the temperature, humidity and pressure of the said medium. The gas analyzer is connected by means of an electrical connection by its output port to the input port of a portable computer with installed software that implements an algorithm for graphical and mathematical processing of the current values of the measured parameters, compiling a database of current and a database of critical parameter values and comparing them, all elements of a single pneumatic line together with a computer make up a measuring -analytical automated complex.

This device provides the possibility of simultaneous measurement of temperature, humidity, pressure and composition of the measured multicomponent gaseous medium of sealed containers with electronic devices, as well as the possibility of comparing the current parameters of this medium with their critical values acceptable for structures of this type.

However, it has the following disadvantages:

- does not save the received data to the internal memory of the gas analyzer;

- does not have the possibility of remote and autonomous modes of operation;

- operation requires direct access to the controls and indications;

- the gas analyzer is turned on and off in manual mode;

- changes the parameters of the analyzed gaseous medium (when used in confined spaces), since for analysis, it is required to sample the gaseous medium from the hermetic volume.

The technical result obtained by using the proposed invention is the possibility of simultaneous measurement of temperature, humidity, pressure and composition of the measured multicomponent gaseous medium in hermetic volumes without changing its composition.

The specified technical result is achieved by the fact that the gas control device containing an analog-to-digital converter, a microcontroller, a power supply module, sensors for hydrogen, oxygen, pressure, as well as temperature and humidity and a PC with the ability to connect to the microcontroller, according to the invention, is equipped with a non-volatile memory connected to the microcontroller , a real-time clock and a power supply control unit, which is connected to the power supply module, oxygen and hydrogen sensors are connected through conversion elements to an analog-to-digital converter, which is connected to a microcontroller connected to pressure, temperature and humidity sensors, holes are made in the device case, on the contrary which the sensors are located.

The entire set of essential features provides the claimed technical result. This was achieved due to the following: the presence of non-volatile memory made it possible to save the calibration characteristics of sensors, parameters and measurement results with current real-time values, and also made it possible to use a PC periodically, rather than constantly connected; making holes in the housing, opposite which the sensors are located, made it possible to measure the parameters of the gaseous medium without changing its composition directly at the installation site of the device; at the same time, the joint use of sensors for measuring the parameters of the gaseous medium (absolute pressure, temperature and relative humidity) and its composition (oxygen and hydrogen concentration), as well as the use of a microcontroller and the presence of a power supply module, makes it possible to simultaneously control the parameters and composition of the multicomponent gaseous medium in the test hermetic volume. As a result, the possibility of simultaneous measurement of temperature, humidity, pressure and composition of the measured multicomponent gaseous medium in hermetic volumes without changing its composition has been achieved.

When analyzing the prior art, no analogues were found that are characterized by features that are identical to all the essential features of this invention. And also, the fact of the popularity of the influence of the features included in the formula on the technical result of the proposed technical solution has not been revealed. Therefore, the claimed invention meets the conditions of "novelty" and "inventive step".

In FIG. 1 shows a diagram of the proposed gas control device.

In FIG. 2 shows the proposed device inside the controlled object.

The gas control device (Fig. 1, 2) contains located in the housing 1 analog-to-digital converter 2 (ADC), conversion elements 3, 4 (EP), microcontroller 5 (MC), power supply module 6 (ME), non-volatile memory 7 ( ENP), real time clock 8 (RTC), power control unit 9 (BUP) and sensors for hydrogen 10 (DV), oxygen 11 (DK), pressure 12 (DD), and humidity and temperature 13 (DVT). DD, DVT, ADC, ENP, BUP and RTC are connected to MK 5. DK 11, DV 10 are connected to ADC 2 through conversion elements 3, 4, ME 6 is connected to BUP 9. The device is also equipped with PC 14 with the ability to connect to MK 5 In the body 1 of the device, holes 15 are made, opposite which all the above sensors are located inside the body.

The gas control device operates as follows. The device is placed in a controlled gas environment 16 (Fig. 2). Through the holes located on the side surfaces of the device body, the analyzed gaseous medium diffuses to the sensors that perform the measurement. The measurement results are transmitted to the microcontroller 5.

The measurement of the volumetric content of oxygen and hydrogen is carried out using oxygen sensors 11 and hydrogen 10 (for example, electrochemical), which produce an output signal in the form of a constant electrical voltage proportional to the partial pressure of oxygen and hydrogen in the gaseous medium. Further, the signals are amplified to the required level, using conversion elements 3 and 4, and fed to the input of ADC 2 and then transferred to MK 5.

All received data, with reference to the current time received from the RTC 8, MK 5 writes to the ENP 7.

The conversion of the recorded values stored in the ENP 7 of the device into the values of the corresponding physical quantities is carried out by the corresponding program in the process of obtaining data when the device is connected to PC 14. The conversion is carried out by the program using the calibration coefficients determined during the manufacture of the device and recorded in its ENP 7.

The power supply of the gas control device is carried out from the ME 6 (for example, electrochemical) using the power control unit 9.

The measured parameters determine the volume fractions of hydrogen, oxygen, absolute pressure, temperature, relative humidity.

Calculation of the value of the absolute pressure of the gas mixture is carried out in accordance with the formula:

where P is the current value of absolute pressure, kPa;

K, V, a ₀ , a ₁ , a ₂ , b ₀ , b ₁ , b ₂ - coefficients determined during the calibration of the absolute pressure sensor;

N - ADC code value;

Т - current temperature value, °С.

The calculation of the value of the partial pressure of hydrogen is carried out in accordance with the formula:

Where - current value of hydrogen partial pressure, kPa;

K, V, a ₀ , a ₁ , a ₂ , b ₀ , b ₁ , b ₂ - coefficients determined during the calibration of the hydrogen sensor;

N - ADC code value;

T - current temperature value, °C.

The conversion of the value of the partial pressure of hydrogen into the value of the volume fraction of hydrogen is carried out in accordance with the formula:

Where - value of the volume fraction of hydrogen, %;

- value of hydrogen partial pressure, kPa;

P is the current value of the absolute pressure of the measured gaseous medium, kPa.

The calculation of the value of the partial pressure of oxygen is carried out in accordance with the formula:

Where - current value of oxygen partial pressure, kPa;

K, V, a ₀ , a ₁ , a ₂ , b ₀ , b ₁ , b ₂ - coefficients determined when calibrating the oxygen sensor;

N - ADC code value;

Т - current temperature value, °С.

The conversion of the value of the partial pressure of oxygen into the value of the volume fraction of oxygen is carried out in accordance with the formula:

Where - the value of the volume fraction of oxygen,%;

- value of oxygen partial pressure, kPa;

P is the current value of the absolute pressure of the measured gaseous medium, kPa.

Relative humidity and temperature values are calculated according to the formula:

where ƒ is the calculated value;

K, V - coefficients determined during the calibration of a temperature sensor or a relative humidity sensor;

N - ADC code value.

The measurement results are processed automatically in accordance with the formulas using the software.

Thus, the use of a gas medium control device will allow simultaneous, automatic, autonomous determination of the volume fraction of hydrogen, oxygen, absolute pressure, relative humidity, temperature of a multicomponent gas medium in hermetic volumes without changing its composition.

For the claimed invention in the form as it is described in the claims, the operability of the gas medium control device and the ability to achieve the specified technical result are experimentally confirmed. The tool that embodies the claimed device in its implementation is intended for use in gas analytical systems, for monitoring the gas atmosphere in the premises of industrial enterprises with hazardous production conditions, in particular for ensuring hydrogen explosion safety, in scientific research, including for studying gas evolution in confined spaces and determination of the corrosive state of the tested structures, which provides the collection of data on the concentration of toxic and explosive substances.

Therefore, the claimed invention meets the condition of "industrial applicability".

Claims (1)

A gas control device containing an analog-to-digital converter, a microcontroller, a power supply module, sensors for hydrogen, oxygen, pressure, as well as temperature and humidity, and a PC with the ability to connect to a microcontroller, characterized in that it is equipped with a non-volatile memory connected to the microcontroller, a real-time clock and power supply control unit, which is connected to the power supply module, oxygen and hydrogen sensors are connected through conversion elements to an analog-to-digital converter, which is connected to a microcontroller connected to pressure, temperature and humidity sensors, holes are made in the device case, opposite which the sensors are located.