RU2792322C1 - Gas analyser - Google Patents

Abstract

FIELD: measuring technology.

SUBSTANCE: invention relates to devices designed to determine the concentration and transmit information about the content of flammable gases and vapours of flammable liquids, toxic gases and oxygen in the air, as well as giving a warning signal about the corresponding levels. The gas analyser includes a housing with a measuring chamber attached to it, made with the possibility of inlet and outlet of the analysed medium, in which a sensitive element is placed for measuring the parameters of the analysed medium, and on the surface of the housing there is a cable entry for connecting external circuits and a connector for a contact connection unit, and the main electronic unit with a microprocessor, a digital-to-analogue converter unit, an interface unit are located inside the housing. Additionally, the gas analyser contains a radio communication unit installed inside the housing to provide remote access to the gas analyser and an indication unit for displaying operating information outside the housing, wherein the interface unit connects the digital-to-analogue converter unit, the radio communication unit, the sensing element and the display unit with the main electronic unit, and the digital-to-analogue converter unit is configured to form a unified analogue signal, and its output is connected to the contact connection unit.

EFFECT: improving the functional and operational qualities of the gas analyser.

12 cl, 3 dwg

Description

The field of technology to which the invention belongs

The present invention relates to the field of measuring technology, namely, to devices designed to determine the concentration of gases, in particular, methane and other gaseous hydrocarbons (propane, hexane, etc.), and which can be used to transmit information about the content of combustible gases and vapors of combustible liquids (including vapors of petroleum products), toxic gases and oxygen in the air of the working area, technological gaseous media, spaces of industrial facilities, pipelines and air ducts, and warning alarms about the corresponding values.

State of the art

From RU 2413934 a gas analyzer is known, consisting of a sensor and an electronic unit, which are interconnected by a cable, and designed for continuous measurement of molecular oxygen in gas flows of a technological chain.

The disadvantage of this gas analyzer is the low functionality and operational capabilities, due to the fact that the electronic control unit is not able to diagnose the health of the power supply circuits or the quality of the microcontroller program, there is no possibility of calibrating the device remotely via a radio channel.

The closest in terms of functionality is the gas analyzer disclosed in RU 77072 U1, which includes a power supply, a gas sensor, an audible and light alarm unit, an external circuit control unit, an automatic gas shutoff unit and a control circuit for this unit.

The disadvantage of this device is low functionality and operational capabilities, in particular, due to the fact that the sound and light signaling unit is not able to transmit digital values of the measured parameter to the outside, which does not allow receiving remotely or seeing information about the amount of gas content in the analyzed (measured) medium directly. on the device, in addition, there is no possibility of calibrating the device remotely via a radio channel.

The closest in terms of set of features is a gas analyzer disclosed in RU 191610 U1, which offers an infrared gas analyzer consisting of a cylindrical body, on the surface of which there is a connector for connecting external circuits, and inside which an infrared optical sensor is located, including holes for inlet and analyzed gas output, an infrared LED, interference filters and a gas cell located along the infrared radiation of the LED with infrared radiation focusing lenses, infrared radiation photodetectors and an electronic control unit, including a communication board to which a control microcontroller is connected, an interface signal generator.

The disadvantage of this gas analyzer is also low functional and operational qualities, which do not allow to improve the reliability and safety of the device. This disadvantage is due to the fact that the electronic control unit, which includes a communication board to which the control microcontroller is connected, is not capable of diagnosing the health of the power circuits or the quality of the microcontroller program. There is no radio unit in the electrical circuit to provide remote access to the gas analyzer, in particular, the transmission of measurement data and calibration of the device remotely via the radio channel, and this requires the connection of external cables. Also, there is no indication block for displaying operating information outside the case, in particular, for prompt display of measured values on the device itself, and there is no provision for measuring the temperature of the atmosphere inside the case and, accordingly, monitoring the temperature of electronic units inside the case.

Disclosure of the essence of the invention.

The objective of the proposed technical solution is to improve the functional and operational qualities of the gas analyzer.

To solve this problem, a gas analyzer is proposed, which has a housing with a measuring chamber attached to it, made with the possibility of inlet and outlet of the analyzed medium, in which a sensitive element is placed for measuring the parameters of the analyzed medium, and on the surface of the housing there are a cable entry for connecting external circuits and a block connector contact connections, and inside the housing there is a main electronic unit with a microprocessor, a digital-to-analog converter unit and an interface unit. The proposed gas analyzer is characterized in that it additionally contains a radio communication unit installed inside the housing to provide remote access to the gas analyzer and an indication unit for displaying operating information outside the housing, the interface unit connecting the digital-to-analog converter unit, the radio communication unit, the sensing element and the display unit with the main electronic unit , and the digital-to-analog converter unit is configured to form a unified analog signal and its output is connected to the contact connection unit.

These blocks are preferably made on the respective printed circuit boards and are interconnected by a wire loop connecting the blocks through plug connectors installed on the printed circuit boards of these blocks.

The body of the gas analyzer is preferably made of metal, while the measuring chamber is made of plastic and is rigidly attached to the body by a suitable fastener (eg threaded or pinned) through a hole in the surface of the body.

The display unit is preferably provided on the surface of the housing with a display device for displaying measured values, which may be a display for displaying numerical values of measured parameters.

Preferably, a temperature sensor is installed in the interface unit to measure the temperature of the atmosphere inside the housing and to control the temperature of the electronic units placed therein. Moreover, the interface unit is a printed circuit board module, including: a circuit for matching and distributing signals to the main electronic unit from peripheral devices; protection scheme of the main electronic unit; a power off delay circuit and a temperature sensor installed on the printed circuit board of the interface unit.

In one embodiment, the sensing element is made in the form of an optical sensor, containing: an optical lens; infrared beam emitter; infrared receiver; digital signal conditioner.

The radio communication unit is preferably a transceiver installed inside the housing and connected by a plug connector to the interface unit. The radio communication unit can be additionally designed for wireless calibration of the sensitive element, remote transmission of measurement data.

The technical result of the claimed invention is to improve the reliability and safety of the gas analyzer.

The specified technical result is achieved by means of the above set of features with distinctive features that directly affect the specified technical result.

Namely, unlike analogues and the prototype, in the claimed gas analyzer, a radio communication unit is installed, which makes it possible to connect the main electronic unit with other external devices via a radio communication channel to configure and calibrate the sensing element and change the measurement parameters.

This solution allows you to transfer measurement data, configure and calibrate the device in hazardous areas without using wired connections, thereby not violating the tightness of the gas analyzer, which in turn increases the reliability and safety of the device.

The display unit installed in the gas analyzer housing can display the digital value of the concentration of combustible gases and the digital value of the unified analog signal transmitted from the analog-to-digital converter unit to external control circuits.

This solution additionally increases the functionality and performance, and also allows you to quickly transfer operating information, including measurement data, and check the performance of the gas analyzer without connecting external measuring instruments. This does not violate the tightness and integrity of external circuits, which also affects the reliability and safety of the device.

In addition, unlike analogs and prototype, in the proposed gas analyzer there is an interface unit that combines the data of the sensitive element, the radio communication unit, the digital-to-analog converter unit, an additional temperature sensor and the display unit into a common serial interface and transmits data to the main electronic unit with the ability to provide control power supply and temperature circuits inside the gas analyzer case.

Such a solution improves performance in terms of improving the reliability and safety of the gas analyzer, since it helps prevent failure of the gas analyzer components, in particular, the sensitive element, the radio communication unit, the digital-to-analog converter unit and the display unit, in particular, due to exceeding the operating temperature or program freezes.

Accordingly, the design of the proposed gas analyzer (gas concentration meter), among other things, is advantageous and effective in that it is capable of performing self-diagnosis, as a result of which, at least in part, preventing malfunction of the internal units of the device and receiving or transmitting information via a radio communication channel or displaying information on the display unit about the analyzed medium and the quality of the gas analyzer, thereby excluding depressurization, violation of the integrity of electrical circuits, which can occur when connecting wired measuring instruments.

As a result, the proposed technical solution improves the reliability and safety of the gas analyzer.

Brief description of the figures

The figures show:

fig. 1 - front view of the gas analyzer;

fig. 2 - side view of the gas analyzer;

fig. 3 - functional diagram of the gas analyzer.

Implementation of the invention.

Shown in FIG. 1 and 2, the gas analyzer has a sealed housing 1, preferably made of metal such as aluminum or stainless steel. The body 1 has a main cylindrical part, on the front side of which there is a front cover 2 provided with a thread.

From below, a plastic measuring (damper) chamber 3 is hermetically attached to the main part of the body 1, containing holes for the penetration of the analyzed environment into it (under the influence of the pressure of the environment itself) and designed to protect the sensitive element from dust, precipitation and mechanical damage. Namely, the medium enters the measuring chamber 3 through the inlet in its lower section and exits through the outlets 4 to exit the analyzed medium.

On the front side of the housing 1 there is a viewing window/glass 5 fixed on the front cover 2 and designed to review the indication displayed on the display installed in the main part of the housing. In particular, inside the aluminum case, on the front side, the board of electronic components and the display are mounted, and the electronic components are closed with an aluminum cover, in the middle of which a viewing glass is installed. The display can display information such as combustible gas concentration percentage, measurement unit, radio signal strength, and service data for maintenance.

On the surface of the housing 1 there is a mounting hole 6 and a sealed cable gland 7 for connecting external circuits, in particular, made in the form of a sealing ring with a through hole, inserted into the hole of the aluminum housing and pressed by means of a threaded connection with a fastener, for example, a bolt with a through hole , through which the electrical circuits of the device power supply and the analog signal circuit containing data on the concentration of combustible gases in the analyzed medium pass, which are connected to the block of contact connections installed in the hole on the back side of the case 1 and closed by the back cover 9. On the right side (on Fig. 1) of the aluminum case 1 has a threaded hole 8 for connecting the ground terminal.

The rear cover 9 is installed on the back side of the housing 1 to protect the terminal connections and is also threaded. The cable with current-carrying circuits can be passed through the cable entry and fixed with a bolt, and the back cover provides, if necessary, the installer's access to the terminals of the contact connection block in order to connect electrical circuits to them.

The plastic measuring chamber 3 is fastened from the bottom of the main part of the housing 1 by means of bolted connections, for example, through a hole 10 in the surface of the housing (one is shown, but there may be several, spaced around the circumference).

In FIG. 3 is a functional diagram of the proposed gas analyzer, showing its main blocks located inside the housing 1, and their functional relationship with each other. Thin lines indicate power circuits, wide arrows indicate signals.

In particular, inside the housing 1 are placed: a block of contact connections 11; power supply 12; main electronic unit 13; interface block 14; block digital-to-analogue converter 15; sensing element 16; radio communication unit 17; indication block 18. These blocks are preferably carried out on the corresponding printed circuit boards and are interconnected by a wire loop connecting the blocks through plug-in connectors installed on the printed circuit boards of these blocks.

As a block of contact connections 11 for connecting electrical circuits and a power supply 12, means common to such devices and well known to specialists can be used.

The main electronic unit 13 may also physically be a conventional microcontroller equipped with a microprocessor.

The interface unit 14 is a printed circuit board module, in particular including:

a) a scheme for matching and distributing signals to the main electronic unit from peripheral devices;

b) protection scheme of the main electronic unit;

c) power off delay circuit.

An additional temperature sensor is also installed in the interface unit 14, which is part of the diagnostics complex and performs the task of controlling the air temperature inside the gas analyzer housing. The location of the temperature sensor in the interface block is most preferable, since the printed circuit board of the interface block is in contact with the air space of the housing cavity and is located in the central part of the housing. Thus, the installation of a temperature sensor in the interface unit provides the best conditions for measuring the temperature of the atmosphere inside the case and ensuring temperature control of the electronic units located in it, which further increases the reliability and safety of the device.

Signals coming from other blocks connected to the interface block 14 by means of plug connectors and connectors pass through the signal matching and distribution circuit (a), which matches the physical voltage levels of these blocks with the physical level of the main electronic block and distributes these signals to the outputs of the main electronic block. Each signal passes through the protection circuit of the main electronic unit (b), which is a protection for excess voltage and current, consisting of circuits of zener diode assemblies and current-limiting resistances. The mentioned temperature sensor is installed on the printed circuit board to monitor the air temperature inside the aluminum case. In the event of a deviation of the supply voltage generated by the power supply unit 12 (surge or short circuit), or a deviation of the temperature inside the case from the nominal values, the protection circuit of the main electronic unit (b) will operate, the power supply unit 12 will turn off, and the power off delay circuit (c), consisting of capacitors installed on the printed circuit board of the interface unit 14, will provide short-term power supply to the main electronic unit so that the controller has time to generate and save a fault report and, if necessary, send it via radio to the client station. The client station can be a laptop or portable communicator connected to this radio channel. The task of the client station is to request information (metrological data, health status, archive, etc.) for monitoring the device and its adjustment.

Thus, the interface unit 14 does not allow direct communications between the units and the main electronic unit (controller) and is preferably equipped with over-power and short circuit protection, in particular, due to the installation of a power-off delay circuit in the interface unit, which stores the stored electricity in capacitors and in the event of a failure or interruption of the supply circuits, allows the controller to analyze the failure and generate a report. In general, the task is additionally solved so that the device is not only able to self-diagnose, but has time to collect and save data after a failure and turning off the device. That is, a means of registering recent events (black box) is provided.

All this allows to significantly increase the reliability and safety of the gas analyzer, especially in critical operating conditions. For example, gas analyzer installation sites may be near furnaces, burners, or heaters. Such conditions become critical during the operation of sensors and can lead to overheating and failure of electronic components. In practice, it is almost impossible to trace such a malfunction, since the radio components may not visually show signs of damage. Monitoring the internal environment of the gas analyzer will help to avoid overheating, as the protection will work, and the report will indicate that the temperature is exceeded. Also, a report generated by the controller at the time of a sensor failure will help the service center speed up and improve the quality of repairs based on data downloaded from the black box.

The sensing element 16 is an optical sensor containing:

- an optical lens (mirror);

- an infrared beam emitter;

- receiver of infrared radiation (IR);

- digital signal generator.

The sensitive element is connected to the plug connector in the hole at the bottom of the body 1. Outside, along the axis of this hole, the casing of the measuring (damper) chamber is put on the body 1, which is fixed with bolted connections located perpendicular to the axis of this hole.

When power is applied, the IR Emitter (Infrared Signal Emitter) generates a beam into a mirror that is set at a fixed angle so that the beam hits an IR Receiver (Infrared Signal Receiver) which is parallel to the IR Emitter. The IR receiver converts the IR radiation energy into electrical energy. When a combustible gas enters between the emitter and the mirror, the intensity of the IR radiation is absorbed by this gas, thereby reducing the level of electric charge on the IR receiver. The electric charge signal is converted into a digital signal by a digital signal conditioner.

The radio communication unit 17 is a transceiver installed inside the housing and connected by a plug connector to the interface unit. This allows the customer (operator, service or maintenance personnel) to remotely access the gas analyzer and change its configuration, as well as receive measurement information and operation status. Namely, the introduction of this module additionally allows:

- duplicate the communication channel in case of a cable break;

- calibrate the sensor and make changes to the work remotely;

- perform manipulations with several gas analyzers at once (speeds up the service time);

- adjust the operation of the gas analyzer without opening the shell and without violating the integrity of the explosion-proof shell in explosive zones (increase in reliability in operation).

The display unit 18 for displaying digital values of the measured concentration of combustible gases contains a display, for example, a liquid crystal display (LCD) or an organic light emitting diode (OLED) display. During operation of the device, a digital signal with data is continuously supplied from the main electronic unit, which, in turn, is converted into information objects in the working field of the display unit matrix in the form of text, bar graphs and numbers (the indicated types of displays are most suitable for outputting this kind of data, using which the user will be able to receive this data without connecting external circuits / devices). In particular, the following information may be displayed:

concentration of the measured medium;

unit of measurement;

molecular formula of the gas;

radio antenna signal strength;

device operation status;

symbols of reaching the threshold concentration;

diagnostic error codes;

device number or tag.

The start of operation of the device begins with the supply of voltage to the block of contact connections 11 and the start of the power supply 12, which are connected by a wire loop connecting the blocks through plug connectors installed on the printed circuit boards of the blocks. Power supply 12 generates the appropriate level of supply voltage for each individual unit. When the supply voltage in the sensitive element 16 reaches the norm, the digital signal generator installed in the sensitive element 16 will continuously transmit to the interface unit 14 a signal with data on the concentration of combustible gases in the analyzed medium and the quality of the sensitive element 16. The radio communication unit 17 receives commands via radio channel from the client (for example, a laptop or portable communicator connected to this radio channel) and transmits to the interface unit 14, then receives a signal with data from the interface unit 14 and transmits back over the radio channel. The digital-to-analog converter unit 15 receives from the interface unit 14 a digital signal containing data on the concentration of combustible gases in the analyzed medium, converts and transmits a unified analog signal containing data on the concentration of combustible gases in the analyzed medium, to the block of contact connections 11 (the unified signal is a proportional the value of a physical quantity the value of a certain type (current, voltage) of the output signal of the converter, in a certain range of its possible changes (for example: current in the range of 4-20mA, voltage in the range of ±5V or 0-10V)).

In addition, the digital-to-analog converter unit 15 transmits to the interface unit 14 a digital signal with data on the temperature of the digital-to-analog converter unit 15. The display unit 18 receives a digital signal with data on the concentration of combustible gases in the analyzed medium from the interface unit 14 and presents the corresponding digital values on the display device 5, for example, on said LCD or OLED display. The interface unit 14 with a temperature sensor installed inside receives digital signals from the radio communication unit 17, the digital-to-analog converter unit 15, the sensitive element 16 and the temperature sensor built into the interface unit 14, coordinates the physical levels of the signals and sends them to the main electronic unit 13. The main electronic unit 13 receives digital signals with data on the temperature inside the device, the concentration of combustible gases in the analyzed medium, the supply voltages of all units of the device from the interface unit 14.

The increase in functionality and performance, ensuring the reliability and safety of work, is achieved, in particular, due to the fact that the main electronic unit 13, which continuously monitors the temperature inside the device using a temperature sensor installed inside the interface unit 14, and the voltage in the power supply circuits 12, turns off the device in case of excess temperature inside the device, excess voltage in the electrical circuits of the power supply 12, generates a digital signal with data on the temperature increase inside the device, excess voltage in the electrical circuits of the power supply 12, saves a fault report and, if necessary, sends it to radio channel to the address of the client station through the radio communication unit 17. This solution helps to prevent the failure of the gas analyzer due to excess temperature inside the device or excess voltage in the circuits of the power supply unit 12, i.e. to increase the reliability/operability of the gas analyzer and the safety of its operation. The presence in the proposed gas analyzer radio communication unit 17 provides the ability to connect the main electronic unit 13 with other external devices via a radio channel to configure, test and calibrate the device. Thus, operational maintenance personnel can service the gas analyzer remotely without opening the device, which in turn increases the safety of the device and the efficiency of maintenance without violating the tightness and integrity of external circuits. This is additionally facilitated by the display unit, in particular, displaying digital data, as it allows, if necessary, to obtain measurement data and check the performance of the gas analyzer without connecting external measuring instruments, thereby not violating the tightness and integrity of external circuits.

Claims (12)

1. A gas analyzer comprising a housing with a measuring chamber attached to it, made with the possibility of inlet and outlet of the analyzed medium, in which a sensitive element is placed for measuring the parameters of the analyzed medium, and on the surface of the housing there is a cable entry for connecting external circuits and a connector of the contact connection block, and inside the housing there is a main electronic unit with a microprocessor, a digital-to-analogue converter unit, an interface unit, characterized in that it additionally contains a radio communication unit installed inside the housing to provide remote access to the gas analyzer and an indication unit for displaying operating information outside the housing, the interface unit connecting the unit digital-to-analog converter, a radio communication unit, a sensitive element and an indication unit with the main electronic unit, and the digital-to-analog converter unit is configured to generate a unified analog signal, and its output is connected with contact block. 2. The gas analyzer according to claim 1, characterized in that these blocks are made on the corresponding printed circuit boards and are interconnected by a wire loop connecting the blocks through plug connectors installed on the printed circuit boards of these blocks. 3. The gas analyzer according to claim. 1 or 2, characterized in that the display unit is equipped with a display device located on the surface of the housing for displaying the measured values. 4. The gas analyzer according to claim 3, characterized in that the display device is a display for displaying the numerical values of the measured parameters. 5. A gas analyzer according to any of the preceding paragraphs, characterized in that a temperature sensor is installed in the interface unit to measure the temperature of the atmosphere inside the housing and to control the temperature of the electronic units located in it. 6. The gas analyzer according to any of the previous paragraphs, characterized in that the interface unit is a printed circuit board module, including: a circuit for matching and distributing signals to the main electronic unit from peripheral devices; protection scheme of the main electronic unit; power off delay circuit. 7. Gas analyzer according to claim 6, characterized in that the temperature sensor is installed on the printed circuit board of the interface unit. 8. The gas analyzer according to any of the previous paragraphs, characterized in that the sensing element is an optical sensor, containing: an optical lens; infrared beam emitter; infrared receiver; digital signal conditioner. 9. The gas analyzer according to any of the previous paragraphs, characterized in that the radio communication unit is a transceiver installed inside the housing and connected by a plug connector to the interface unit. 10. Gas analyzer according to any one of the preceding claims, characterized in that the radio communication unit is additionally designed for wireless calibration of the sensing element. 11. The gas analyzer according to any of the preceding paragraphs, characterized in that the radio communication unit is additionally designed for remote transmission of measurement data. 12. The gas analyzer according to any of the preceding paragraphs, characterized in that the body is made of metal, and the measuring chamber is made of plastic and is attached to the body by means of a fastener through a hole in the surface of the body.

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