CN109507276B - Novel ambient air TVOC on-line monitoring system - Google Patents
Novel ambient air TVOC on-line monitoring system Download PDFInfo
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- CN109507276B CN109507276B CN201811562076.8A CN201811562076A CN109507276B CN 109507276 B CN109507276 B CN 109507276B CN 201811562076 A CN201811562076 A CN 201811562076A CN 109507276 B CN109507276 B CN 109507276B
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Abstract
The invention provides a novel on-line monitoring system for ambient air TVOC, which comprises a man-machine interaction module, a control device and an ambient air TVOC monitoring gas circuit, wherein the ambient air TVOC monitoring gas circuit comprises a wide-range monitoring gas circuit, a small-range monitoring gas circuit and a gas circuit switching device; the man-machine interaction module is connected with the control device and is used for inputting functional instructions and functional parameters to the control device; the control device controls the wide-range monitoring gas circuit to work according to the functional instruction and the functional parameter, and controls the gas circuit switching device to switch the wide-range monitoring gas circuit to the small-range monitoring gas circuit according to the environment TVOC value monitored by the wide-range monitoring gas circuit; the man-machine interaction module is also respectively connected with the wide-range monitoring air circuit and the small-range monitoring air circuit and is used for displaying the environment TVOC value monitored by the wide-range monitoring air circuit or the small-range monitoring air circuit.
Description
Technical Field
The invention relates to an ambient air TVOC monitoring system, in particular to a novel ambient air TVOC on-line monitoring system.
Background
With the increasing popularization of industrial pollution and automobiles, the content of TVOC in the ambient air is increased, and the TVOC in the ambient air can directly cause harm to human health and can interact to cause photochemical pollution. Therefore, rapid and accurate monitoring of the TVOC content in ambient air is becoming more and more urgent. Because the TVOC content in the ambient air is in trace level, most of the existing equipment for monitoring the TVOC content in the market is realized by adopting a sensor technology, but the application range in air environment monitoring is greatly limited due to the limitations of the sensitivity and the detection limit of a sensor.
In order to solve the above problems, an ideal technical solution is always sought.
Disclosure of Invention
The invention aims at overcoming the defects of the prior art, thereby providing a novel on-line monitoring system for the ambient air TVOC, which has wide application range and high measurement precision.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the novel on-line monitoring system for the ambient air TVOC comprises a man-machine interaction module, a control device and an ambient air TVOC monitoring gas circuit, wherein the ambient air TVOC monitoring gas circuit comprises a wide-range monitoring gas circuit and a small-range monitoring gas circuit which are respectively used for detecting the ambient air TVOC value, and a gas circuit switching device which is used for switching between the wide-range monitoring gas circuit and the small-range monitoring gas circuit; the man-machine interaction module is connected with the control device and is used for inputting functional instructions and functional parameters to the control device; the control device controls the wide-range monitoring gas circuit to work according to the functional instruction and the functional parameter, and controls the gas circuit switching device to switch the wide-range monitoring gas circuit to the small-range monitoring gas circuit according to the environment TVOC value monitored by the wide-range monitoring gas circuit; the man-machine interaction module is also respectively connected with the wide-range monitoring air circuit and the small-range monitoring air circuit and is used for displaying the environment TVOC value monitored by the wide-range monitoring air circuit or the small-range monitoring air circuit.
Based on the above, the air path switching device is an electromagnetic four-way valve, when the electromagnetic four-way valve is powered off, a first interface of the electromagnetic four-way valve is communicated with a fourth interface of the electromagnetic four-way valve, and a second interface of the electromagnetic four-way valve is communicated with a third interface of the electromagnetic four-way valve; when the electromagnetic four-way valve is electrified, a first interface of the electromagnetic four-way valve is communicated with a third interface of the electromagnetic four-way valve, and a second interface of the electromagnetic four-way valve is communicated with a fourth interface of the electromagnetic four-way valve;
The ambient air TVOC monitoring gas circuit comprises a gas inlet, a sampling pump, a pyrolysis straw, a photoionization sensor and a gas outlet, wherein the gas inlet, the sampling pump, a first interface of an electromagnetic four-way valve, a fourth interface of the electromagnetic four-way valve, the photoionization sensor and the gas outlet are sequentially communicated to form the wide-range monitoring gas circuit; the air inlet, the sampling pump, the first interface of the electromagnetic four-way valve, the second interface of the electromagnetic four-way valve, the pyrolysis straw, the third interface of the electromagnetic four-way valve, the fourth interface of the electromagnetic four-way valve, the photoionization sensor and the air outlet are sequentially communicated to form the small-range monitoring air path;
the control device is in control connection with the electromagnetic four-way valve, and the switching of the wide-range monitoring air circuit and the small-range monitoring air circuit is realized by controlling the on-off of the electromagnetic four-way valve.
Based on the above, the gas path switching device comprises a first electromagnetic three-way valve and a second electromagnetic three-way valve, wherein the first electromagnetic three-way valve and the second electromagnetic three-way valve are the same electromagnetic three-way valve; when the electromagnetic three-way valve is powered off, the first interface of the electromagnetic three-way valve is communicated with the third interface of the electromagnetic three-way valve; when the electromagnetic three-way valve is connected, a first interface of the second electromagnetic three-way valve is communicated with a second interface of the electromagnetic three-way valve;
The ambient air TVOC monitoring gas circuit comprises a gas inlet, a sampling pump, a pyrolysis straw, a photoionization sensor and a gas outlet, wherein the gas inlet, the sampling pump, a first interface of a first electromagnetic three-way valve, a third interface of the first electromagnetic three-way valve, a third interface of a second electromagnetic three-way valve, a first interface of the second electromagnetic three-way valve, the photoionization sensor and the gas outlet are sequentially communicated to form the wide-range monitoring gas circuit;
The air inlet, the sampling pump, the first interface of the first electromagnetic three-way valve, the second interface of the electromagnetic three-way valve, the pyrolysis straw, the second interface of the second electromagnetic three-way valve, the first interface of the electromagnetic three-way valve, the photoionization sensor and the air outlet are sequentially communicated to form the small-range monitoring air path;
The control device is in control connection with the first electromagnetic three-way valve and the second electromagnetic three-way valve, and the switching of the wide-range monitoring gas circuit and the small-range monitoring gas circuit is realized by controlling the on-off of the first electromagnetic three-way valve and the second electromagnetic three-way valve.
Based on the above, the control device comprises an MCU main control module, a temperature control module, a data transmission module and a power module, wherein the temperature control module is used for adjusting the temperatures of the gas path switching device, the pyrolysis straw and the gas path pipeline; the data transmission module is used for realizing data transmission; the MCU main control module is respectively connected with the temperature control module, the data transmission module, the sampling pump and the gas circuit switching device, and the power supply module is respectively connected with the MCU main control module, the temperature control module, the data transmission module, the gas circuit switching device and the sampling pump and is used for providing a working power supply.
Based on the above, the temperature control module includes a temperature detection unit, a processor unit, a heating unit and a refrigerating unit, where the temperature detection unit includes a three-wire PT100 platinum resistor, an amplifier AD620 and a multi-channel digital-to-analog converter, where the three-wire PT100 platinum resistor is used to convert a temperature signal into an analog voltage signal, the amplifier AD620 is used to amplify the analog voltage signal, and the multi-channel digital-to-analog converter is used to convert the analog voltage signal into a digital voltage signal; the processor unit is respectively connected with the multichannel digital-to-analog converter, the heating unit and the refrigerating unit, and controls the heating unit to heat or controls the refrigerating unit to refrigerate according to the digital voltage signal.
Based on the above, the monitoring steps of the wide-range monitoring gas circuit are as follows:
The MCU main control module controls the gas circuit switching device to be disconnected and controls the sampling pump and the photoionization sensor to be electrified;
and the ambient gas is pumped in from the air inlet, is sent into the photoionization sensor through the sampling pump and the gas circuit switching device, and the ambient gas TVOC value is detected through the photoionization sensor.
Based on the above, the monitoring steps of the small-range monitoring gas circuit are as follows:
Enrichment sampling stage
The MCU main control module controls the gas circuit switching device to be communicated and controls the sampling pump and the photoionization sensor to be electrified;
Pumping in ambient gas from the gas inlet, evacuating the ambient gas from the gas outlet through the sampling pump, the gas path switching device, the pyrolysis straw and the photoionization sensor, and enriching and adsorbing TVOC in the ambient gas in the pyrolysis straw;
Heating stage
The MCU main control module controls the gas circuit switching device to be disconnected, and controls the heating unit of the pyrolysis straw to be started, so that the pyrolysis straw is quickly heated and stabilized to a preset high temperature value, and at the moment, the enriched TVOC in the pyrolysis straw is quickly desorbed;
analysis sample injection stage
The MCU main control module controls the gas path switching device to be communicated and controls the photoionization sensor to be electrified, at the moment, the ambient gas enters the photoionization sensor through the gas inlet, the sampling pump, the gas path switching device and the pyrolysis straw, and the TVOC desorbed from the pyrolysis straw also enters the photoionization sensor along with the ambient gas to carry out content detection;
Refrigeration stage
The MCU main control module controls the gas circuit switching device to be disconnected, controls the sampling pump to be powered off with the photoionization sensor, and controls the refrigerating unit of the pyrolysis straw to be started, so that the pyrolysis straw is rapidly cooled and stabilized to a preset low temperature value.
Based on the above, a flow sensor is further arranged between the exhaust port and the photoionization sensor, the MCU main control module is connected with the flow sensor, and the flow rate of the sampling pump is controlled according to the gas flow collected by the flow sensor so as to realize accurate air intake.
Based on the above, a filter is further arranged behind the air inlet, and the filter is used for filtering particles in the ambient air.
Based on the above, the sampling pump may also be disposed before the exhaust port.
Compared with the prior art, the invention has outstanding substantive characteristics and remarkable progress, and particularly, the invention utilizes the detection technology of combining the enrichment thermal desorption sensor and the photoionization sensor to construct small-range monitoring, expands the detection range of the traditional TVOC detection instrument to the trace level, and well solves the problems of the lowest detection line and the sensitivity of the traditional TVOC detection instrument; the switching of the wide-range monitoring gas circuit and the small-range monitoring gas circuit is realized by controlling the gas circuit switching device according to the content control device of the TVOC in the ambient gas, so that the application range of the online monitoring system of the ambient air TVOC is wider; the sampling pump and the flow sensor are controlled by the control device, so that the accurate and flexible collection of the sample gas is realized; the invention has the advantages of high sensitivity, low detection line, convenient maintenance and wide application range.
Drawings
Fig. 1 is a schematic structural view of embodiment 2 of the present invention.
Fig. 2 is a wide-range monitoring gas circuit of embodiment 2 of the present invention.
Fig. 3 is a small-scale monitoring gas circuit of embodiment 2 of the present invention.
Fig. 4 is a schematic diagram of a control device of the present invention.
Fig. 5 is a schematic structural view of embodiment 3 of the present invention.
Fig. 6 is a wide-range monitoring gas circuit of embodiment 3 of the present invention.
Fig. 7 is a small-scale monitoring gas circuit of embodiment 3 of the present invention.
Fig. 8 is a schematic structural view of embodiment 5 of the present invention.
Fig. 9 is another structural schematic diagram of embodiment 5 of the present invention.
Fig. 10 is a schematic structural view of embodiment 6 of the present invention.
Fig. 11 is another structural schematic diagram of embodiment 6 of the present invention.
Fig. 12 is a schematic structural view of embodiment 7 of the present invention.
Fig. 13 is another structural schematic diagram of embodiment 7 of the present invention.
In the figure: 1. an air inlet; 2. a filter; 3. a sampling pump; 4. an electromagnetic four-way valve; 5. pyrolyzing the straw; 6. a photoionization sensor; 7. a flow sensor; 8. an exhaust port; 9. a first electromagnetic three-way valve; 10. and a second electromagnetic three-way valve.
Detailed Description
The technical scheme of the invention is further described in detail through the following specific embodiments.
Example 1
The invention provides a novel on-line monitoring system for ambient air TVOC, which comprises a man-machine interaction module, a control device and an ambient air TVOC monitoring gas circuit, wherein the man-machine interaction module comprises a magnetic rod, a display screen and other units, and the magnetic rod is used for selecting functional instructions and setting functional parameters in a starting-up stage. The display screen is mainly used for displaying the information such as the current time, the current state information, the progress condition of the current flow, the monitored TVOC content value and the like.
After the novel environment air TVOC on-line monitoring system is powered on, equipment is self-checked firstly, after the self-check is passed, the equipment enters a main interface, the main interface is mainly divided into functional instructions such as cycle monitoring, calibration, historical data checking and setting, and the calibration is divided into baseline calibration and characteristic point calibration, and the calibration is carried out by adopting a linear interpolation algorithm; at the moment, the two magnetic bars on the panel can be combined with prompt information of the display screen to select the function instruction and set the function parameters.
The environment air TVOC monitoring air circuit comprises a wide-range monitoring air circuit and a small-range monitoring air circuit which are respectively used for detecting the environment air TVOC value, and an air circuit switching device which is used for switching between the wide-range monitoring air circuit and the small-range monitoring air circuit; the control device controls the wide-range monitoring gas circuit to work according to the functional instruction and the functional parameter, and controls the gas circuit switching device to switch the wide-range monitoring gas circuit to the small-range monitoring gas circuit according to the environment TVOC value monitored by the wide-range monitoring gas circuit; the man-machine interaction module is also respectively connected with the wide-range monitoring air circuit and the small-range monitoring air circuit and is used for displaying the environment TVOC value monitored by the wide-range monitoring air circuit or the small-range monitoring air circuit.
The working principle of the embodiment is as follows:
The control device controls the wide-range monitoring gas circuit to work according to the functional instruction and the functional parameter, and controls the gas circuit switching device to switch the wide-range monitoring gas circuit to the small-range monitoring gas circuit according to the environment TVOC value monitored by the wide-range monitoring gas circuit; specifically, when the environmental TVOC value monitored by the wide-range monitoring gas circuit is a small-range (0-1 ppm), the control device controls the gas circuit switching device to act so as to switch the wide-range monitoring gas circuit to the small-range monitoring gas circuit; when the environment TVOC value monitored by the wide-range monitoring gas circuit is wide-range (1 ppm-40 ppm), the control device controls the gas circuit switching device to be not operated, and the wide-range monitoring gas circuit is continuously executed; and the environmental TVOC value monitored by the wide-range monitoring gas circuit or the small-range monitoring gas circuit is displayed through the man-machine interaction module.
According to the invention, the gas circuit switching device is controlled according to the content control device of the TVOC in the ambient gas, so that the switching of the wide-range monitoring gas circuit and the small-range monitoring gas circuit is realized, and the application range of the online monitoring system of the TVOC of the ambient air is wider.
Example 2
This embodiment differs from embodiment 1 in that: as shown in fig. 1, the ambient air TVOC monitoring air path includes an air inlet 1, a sampling pump 3, a pyrolysis straw 5, a photoionization sensor 6 and an air outlet 8, the air path switching device is a 4 electromagnetic four-way valve, when the electromagnetic four-way valve 4 is powered off, a first interface of the electromagnetic four-way valve 4 is communicated with a fourth interface of the electromagnetic four-way valve 4, and a second interface of the electromagnetic four-way valve 4 is communicated with a third interface of the electromagnetic four-way valve 4; when the electromagnetic four-way valve 4 is electrified, a first interface of the electromagnetic four-way valve 4 is communicated with a third interface of the electromagnetic four-way valve 4, and a second interface of the electromagnetic four-way valve 4 is communicated with a fourth interface of the electromagnetic four-way valve 4;
as shown in fig. 2, the air inlet 1, the sampling pump 3, the first interface of the electromagnetic four-way valve 4, the fourth interface of the electromagnetic four-way valve 4, the photoionization sensor 6 and the air outlet 8 are sequentially communicated to form the wide-range monitoring air path.
As shown in fig. 3, the air inlet 1, the sampling pump 3, the first interface of the electromagnetic four-way valve 4, the second interface of the electromagnetic four-way valve 4, the pyrolysis straw 5, the third interface of the electromagnetic four-way valve 4, the fourth interface of the electromagnetic four-way valve 4, the photoionization sensor 6 and the air outlet 8 are sequentially communicated to form the small-range monitoring air path.
The control device is in control connection with the electromagnetic four-way valve 4, and the switching of the wide-range monitoring air circuit and the small-range monitoring air circuit is realized by controlling the on-off of the electromagnetic four-way valve 4
Specifically, as shown in fig. 4, the control device includes an MCU main control module, a temperature control module, a data transmission module and a power module, where the temperature control module is used to adjust the temperature of the pyrolysis straw; the data transmission module is used for realizing data transmission; the MCU main control module is respectively connected with the temperature control module, the data transmission module, the sampling pump 3 and the gas circuit switching device, and the power supply module is respectively connected with the MCU main control module, the temperature control module, the data transmission module, the electromagnetic four-way valve 4 and the sampling pump 3 and is used for providing a working power supply.
Specifically, the temperature control module comprises a temperature detection unit, a processor unit, a heating unit and a refrigerating unit, wherein the temperature detection unit comprises a three-wire PT100 platinum resistor, an amplifier AD620 and a multichannel digital-to-analog converter, the three-wire PT100 platinum resistor is used for converting a temperature signal into an analog voltage signal, the amplifier AD620 is used for amplifying the analog voltage signal, and the multichannel digital-to-analog converter is used for converting the analog voltage signal into a digital voltage signal; the processor unit is respectively connected with the multichannel digital-to-analog converter, the heating unit and the refrigerating unit, and controls the heating unit to heat or controls the refrigerating unit to refrigerate according to the digital voltage signal; preferably, the multi-channel digital-to-analog converter is a 24-bit multi-channel AD7793 device adopting a sigma-delta modulation technology, and the AD7793 device is integrated with a high-precision constant current source, a filter and the like, has self-calibration and system calibration functions, and can eliminate the influence of zero point, full range error and temperature drift; meanwhile, in order to prevent the three-wire PT100 platinum resistor from influencing the measurement accuracy due to self-heating, the high-accuracy constant current source integrated by the AD7793 device is usually selected to be hundreds of microamps, and is set to be 210 microamps, and the temperature control accuracy is not more than +/-0.1 ℃.
The heating unit comprises a heating resistance wire, a bidirectional thyristor type optocoupler and a bidirectional thyristor, wherein a positive input pin of the zero-crossing bidirectional thyristor type optocoupler is connected with a power supply VCC through a resistor, a negative input pin of the zero-crossing bidirectional thyristor type optocoupler is connected with an I/O interface, two output pins of the zero-crossing bidirectional thyristor type optocoupler are respectively connected with an alternating current power supply, one output pin of the zero-crossing bidirectional thyristor type optocoupler is connected with a control end of the bidirectional thyristor, and two fixed ends of the bidirectional thyristor are respectively connected with the alternating current power supply; preferably, the bidirectional thyristor type optocoupler is a zero-crossing bidirectional thyristor type optocoupler MOC3063 with the trigger current of only 5mA, integrates the functions of photoelectric isolation, zero-crossing detection, zero-crossing trigger and the like, avoids the defect that an input channel and an output channel simultaneously control the bidirectional thyristor to trigger, and simplifies the design of an output channel isolation driving circuit.
The bidirectional thyristor type optocoupler controls the heating resistance wire to heat to a preset high temperature value in a zero-crossing power adjustment mode; the zero-crossing power regulation mode is a control method for regulating power by changing the number of alternating current sine waves applied to a load in a given time; the controllable silicon is triggered to be conducted when the voltage (current) crosses zero, and the waveform of the conducted voltage is a complete sine wave or half wave, so that higher harmonic waves are not generated, the load surge current and the current change rate are very small, the voltage of a power grid is not influenced, and communication equipment is not interfered.
The step of judging whether the heating resistance wire is heated to a preset high temperature value by the temperature control module comprises the following steps of: and acquiring the temperature value of the heating resistance wire in real time through the temperature detection unit, judging whether the temperature value change is a heating trend or a cooling trend, if so, further judging whether the temperature of the current heating resistance wire is within a positive and negative 0.1 range of a preset high temperature value, and if so, judging that the heating resistance wire is heated to the preset high temperature value.
The cooling unit is a pumping type cooling unit, the pumping type cooling unit is arranged outside the pyrolysis straw, cold air is pumped into the pumping type cooling unit, and heat in the pyrolysis straw is taken away through the flowing of the cold air, so that the cooling effect is achieved.
The working principle of the invention is as follows:
The MCU main control module is used for controlling the electromagnetic four-way valve 4 to be disconnected so as to execute the wide-range monitoring:
The MCU main control module controls the sampling pump 3 and the photoionization sensor 6 to be electrified;
the ambient gas is pumped in from the air inlet 1, is sent into the photoionization sensor 6 through the sampling pump 3, the first interface of the electromagnetic four-way valve 4 and the fourth interface of the electromagnetic four-way valve 4, and the ambient gas TVOC value is detected through the photoionization sensor 6;
The MCU main control module judges whether the environment TVOC value monitored by the wide-range monitoring gas circuit is of a wide range (1 ppm-40 ppm) or a small range (0-1 ppm), if the environment TVOC value is of a wide range, the MCU main control module does not act, and the wide-range monitoring flow is continuously executed; if the monitoring device is in a small range, the MCU main control module controls the electromagnetic four-way valve 4 to be connected so as to switch the large-range monitoring gas circuit into a small-range monitoring gas circuit, so as to execute a small-range monitoring flow:
Enrichment sampling stage
The MCU main control module controls the sampling pump 3 and the photoionization sensor 6 to be electrified;
ambient gas is pumped from the air inlet 1, and is exhausted from the air outlet 8 through the sampling pump 3, the first interface of the electromagnetic four-way valve 4, the second interface of the electromagnetic four-way valve 4, the pyrolysis straw 5, the third interface of the electromagnetic four-way valve 4, the fourth interface of the electromagnetic four-way valve 4 and the photoionization sensor 6, wherein TVOC in the ambient gas is enriched and adsorbed in the pyrolysis straw 5;
Heating stage
The MCU main control module controls the electromagnetic four-way valve 4 to be disconnected, and controls the heating unit of the pyrolysis straw 5 to be started, so that the pyrolysis straw 5 is quickly heated and stabilized to a preset high temperature value, and at the moment, the TVOC enriched in the pyrolysis straw 5 is quickly desorbed;
analysis sample injection stage
The MCU main control module controls the electromagnetic four-way valve 4 to be connected and controls the photoionization sensor 6 to be electrified, at the moment, ambient gas enters the photoionization sensor 6 through the air inlet 1, the sampling pump 3, a first interface of the electromagnetic four-way valve 4, a second interface of the electromagnetic four-way valve 4, the pyrolysis straw 5, a third interface of the electromagnetic four-way valve 4 and a fourth interface of the electromagnetic four-way valve 4, and the TVOC desorbed from the pyrolysis straw 5 also enters the photoionization sensor 6 along with the ambient gas to carry out content detection;
Refrigeration stage
The MCU main control module controls the electromagnetic four-way valve 4 to be disconnected, controls the sampling pump 3 and the photoionization sensor 6 to be powered off, and controls the refrigerating unit of the pyrolysis straw 5 to be started, so that the pyrolysis straw 5 is rapidly cooled and stabilized to a preset low temperature value.
Example 3
This embodiment differs from embodiment 2 in that: as shown in fig. 5, the ambient air TVOC monitoring air path includes an air inlet 1, a sampling pump 3, a pyrolysis straw 5, a photoionization sensor 6 and an air outlet 8, the air path switching device includes a first electromagnetic three-way valve 9 and a second electromagnetic three-way valve 10, and the first electromagnetic three-way valve 9 and the second electromagnetic three-way valve 10 are the same electromagnetic three-way valve; when the electromagnetic three-way valve is powered off, the first interface of the electromagnetic three-way valve is communicated with the third interface of the electromagnetic three-way valve; when the electromagnetic three-way valve is connected, a first interface of the electromagnetic three-way valve is communicated with a second interface of the electromagnetic three-way valve.
As shown in fig. 6, the air inlet 1, the sampling pump 3, the first interface of the first electromagnetic three-way valve 9, the third interface of the second electromagnetic three-way valve 10, the first interface of the second electromagnetic three-way valve 10, the photoionization sensor 6 and the air outlet 8 are sequentially communicated to form the wide-range monitoring air path.
As shown in fig. 7, the air inlet 1, the sampling pump 3, the first interface of the first electromagnetic three-way valve 9, the second interface of the electromagnetic three-way valve 9, the pyrolysis straw 5, the second interface of the second electromagnetic three-way valve 10, the first interface of the second electromagnetic three-way valve 10, the photoionization sensor 6 and the air outlet 8 are sequentially communicated to form the small-range monitoring air path;
the control device is in control connection with the first electromagnetic three-way valve 9 and the second electromagnetic three-way valve 10, and the switching of the wide-range monitoring gas circuit and the small-range monitoring gas circuit is realized by controlling the on-off of the first electromagnetic three-way valve 9 and the second electromagnetic three-way valve 10.
Example 4
This embodiment differs from embodiment 2 and embodiment 3 in that: the wide-range monitoring and the small-range monitoring are periodic, the analysis period can be preset, and the current default setting is half an hour of one monitoring process.
Example 5
This embodiment differs from embodiment 2 and embodiment 3 in that: as shown in fig. 8 and 9, a flow sensor 7 is further disposed between the exhaust port 8 and the photoionization sensor 6, and the MCU is connected to the flow sensor 7, so as to control the flow rate and the switch closing time of the sampling pump 3 according to the gas flow collected by the flow sensor 7, so as to achieve accurate air intake.
Example 6
This embodiment differs from embodiment 5 in that: as shown in fig. 10 and 11, a filter 2 is further disposed between the air inlet 1 and the sampling pump 3, preferably, the filter 2 is a precision filter 2, and the air flowing through the filter 2 is pretreated to filter the particulate dust and water vapor in the ambient air and the air to be tested, so as to prevent the small particulate matters or water vapor from entering into the air path to affect the performance of the pyrolysis straw 5, thereby prolonging the service life of related components.
Example 7
This embodiment differs from embodiment 2 and embodiment 3 in that: as shown in fig. 12 and 13, the sampling pump 3 may also be disposed before the exhaust port 8.
Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical scheme of the present invention and are not limiting; while the invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that: modifications may be made to the specific embodiments of the present invention or equivalents may be substituted for part of the technical features thereof; without departing from the spirit of the technical proposal of the invention, all of which are covered by the scope of the technical proposal of the invention.
Claims (10)
1. Novel ambient air TVOC on-line monitoring system, its characterized in that: the system comprises a man-machine interaction module, a control device and an ambient air TVOC monitoring gas circuit, wherein the ambient air TVOC monitoring gas circuit comprises a wide-range monitoring gas circuit and a small-range monitoring gas circuit which are respectively used for detecting the ambient air TVOC value, and a gas circuit switching device which is used for switching between the wide-range monitoring gas circuit and the small-range monitoring gas circuit; the man-machine interaction module is connected with the control device and is used for inputting functional instructions and functional parameters to the control device; the control device controls the wide-range monitoring gas circuit to work according to the functional instruction and the functional parameter, and controls the gas circuit switching device to switch the wide-range monitoring gas circuit to the small-range monitoring gas circuit according to the environment TVOC value monitored by the wide-range monitoring gas circuit; the ambient air TVOC monitoring gas circuit comprises a gas inlet, a sampling pump, a pyrolysis straw, a photoionization sensor and a gas outlet; the wide-range monitoring gas circuit comprises a gas inlet, a sampling pump, a gas circuit switching device, a photoionization sensor and a gas outlet; the small-range monitoring gas circuit comprises a sampling pump, a gas circuit switching device, a pyrolysis straw, a photoionization sensor and a gas outlet; when the environment TVOC value monitored by the wide-range monitoring gas circuit is a small range, the control device controls the gas circuit switching device to act so as to switch the wide-range monitoring gas circuit to the small-range monitoring gas circuit; when the environment TVOC value monitored by the wide-range monitoring gas circuit is a wide range, the control device controls the gas circuit switching device to be not operated, and the wide-range monitoring gas circuit is continuously executed; the man-machine interaction module is also respectively connected with the wide-range monitoring air circuit and the small-range monitoring air circuit and is used for displaying the environment TVOC value monitored by the wide-range monitoring air circuit or the small-range monitoring air circuit; wherein, the small measuring range means that the environmental TVOC value is 0-1ppm; the wide range means that the ambient TVOC value is 1ppm to 40ppm.
2. The novel ambient air TVOC online monitoring system of claim 1, wherein: the air circuit switching device is an electromagnetic four-way valve, when the electromagnetic four-way valve is powered off, a first interface of the electromagnetic four-way valve is communicated with a fourth interface of the electromagnetic four-way valve, and a second interface of the electromagnetic four-way valve is communicated with a third interface of the electromagnetic four-way valve; when the electromagnetic four-way valve is electrified, a first interface of the electromagnetic four-way valve is communicated with a third interface of the electromagnetic four-way valve, and a second interface of the electromagnetic four-way valve is communicated with a fourth interface of the electromagnetic four-way valve;
The air inlet, the sampling pump, the first interface of the electromagnetic four-way valve, the fourth interface of the electromagnetic four-way valve, the photoionization sensor and the air outlet are sequentially communicated to form the wide-range monitoring air circuit; the air inlet, the sampling pump, the first interface of the electromagnetic four-way valve, the second interface of the electromagnetic four-way valve, the pyrolysis straw, the third interface of the electromagnetic four-way valve, the fourth interface of the electromagnetic four-way valve, the photoionization sensor and the air outlet are sequentially communicated to form the small-range monitoring air path;
the control device is in control connection with the electromagnetic four-way valve, and the switching of the wide-range monitoring air circuit and the small-range monitoring air circuit is realized by controlling the on-off of the electromagnetic four-way valve.
3. The novel ambient air TVOC online monitoring system of claim 1, wherein: the gas circuit switching device comprises a first electromagnetic three-way valve and a second electromagnetic three-way valve, and the first electromagnetic three-way valve and the second electromagnetic three-way valve are the same electromagnetic three-way valve; when the electromagnetic three-way valve is powered off, the first interface of the electromagnetic three-way valve is communicated with the third interface of the electromagnetic three-way valve; when the electromagnetic three-way valve is connected, a first interface of the electromagnetic three-way valve is communicated with a second interface of the electromagnetic three-way valve;
The air inlet, the sampling pump, the first interface of the first electromagnetic three-way valve, the third interface of the second electromagnetic three-way valve, the first interface of the second electromagnetic three-way valve, the photoionization sensor and the air outlet are sequentially communicated to form the wide-range monitoring air path;
The air inlet, the sampling pump, the first interface of the first electromagnetic three-way valve, the second interface of the electromagnetic three-way valve, the pyrolysis straw, the second interface of the second electromagnetic three-way valve, the first interface of the electromagnetic three-way valve, the photoionization sensor and the air outlet are sequentially communicated to form the small-range monitoring air path;
The control device is in control connection with the first electromagnetic three-way valve and the second electromagnetic three-way valve, and the switching of the wide-range monitoring gas circuit and the small-range monitoring gas circuit is realized by controlling the on-off of the first electromagnetic three-way valve and the second electromagnetic three-way valve.
4. A novel ambient air TVOC on-line monitoring system according to claim 2 or 3, wherein: the control device comprises an MCU main control module, a temperature control module, a data transmission module and a power supply module, wherein the temperature control module is used for adjusting the temperatures of the gas circuit switching device, the pyrolysis straw and the gas circuit pipeline; the data transmission module is used for realizing data transmission; the MCU main control module is respectively connected with the temperature control module, the data transmission module, the sampling pump and the gas circuit switching device, and the power supply module is respectively connected with the MCU main control module, the temperature control module, the data transmission module, the gas circuit switching device and the sampling pump and is used for providing a working power supply.
5. The novel ambient air TVOC online monitoring system of claim 4, wherein: the temperature control module comprises a temperature detection unit, a processor unit, a heating unit and a refrigerating unit, wherein the temperature detection unit comprises a three-wire PT100 platinum resistor, an amplifier AD620 and a multi-channel digital-to-analog converter, the three-wire PT100 platinum resistor is used for converting a temperature signal into an analog voltage signal, the amplifier AD620 is used for amplifying the analog voltage signal, and the multi-channel digital-to-analog converter is used for converting the analog voltage signal into a digital voltage signal; the processor unit is respectively connected with the multichannel digital-to-analog converter, the heating unit and the refrigerating unit, and controls the heating unit to heat or controls the refrigerating unit to refrigerate according to the digital voltage signal.
6. The novel ambient air TVOC on-line monitoring system of claim 5, wherein said wide range monitoring gas circuit comprises the following steps:
The MCU main control module controls the gas circuit switching device to be disconnected and controls the sampling pump and the photoionization sensor to be electrified;
and the ambient gas is pumped in from the air inlet, is sent into the photoionization sensor through the sampling pump and the gas circuit switching device, and the ambient gas TVOC value is detected through the photoionization sensor.
7. The novel ambient air TVOC on-line monitoring system of claim 5, wherein said small-scale monitoring gas circuit comprises the following steps:
Enrichment sampling stage
The MCU main control module controls the gas circuit switching device to be communicated and controls the sampling pump and the photoionization sensor to be electrified;
Pumping in ambient gas from the gas inlet, evacuating the ambient gas from the gas outlet through the sampling pump, the gas path switching device, the pyrolysis straw and the photoionization sensor, and enriching and adsorbing TVOC in the ambient gas in the pyrolysis straw;
Heating stage
The MCU main control module controls the gas circuit switching device to be disconnected, and controls the heating unit in the pyrolysis straw to be started, so that the pyrolysis straw is quickly heated and stabilized to a preset high temperature value, and at the moment, the enriched TVOC in the pyrolysis straw is quickly desorbed;
analysis sample injection stage
The MCU main control module controls the gas path switching device to be communicated and controls the photoionization sensor to be electrified, at the moment, the ambient gas enters the photoionization sensor through the gas inlet, the sampling pump, the gas path switching device and the pyrolysis straw, and the TVOC desorbed from the pyrolysis straw also enters the photoionization sensor along with the ambient gas to carry out content detection;
Refrigeration stage
The MCU main control module controls the gas circuit switching device to be disconnected, controls the sampling pump to be powered off with the photoionization sensor, and controls the refrigerating unit of the pyrolysis straw to be started, so that the pyrolysis straw is rapidly cooled and stabilized to a preset low temperature value.
8. The novel ambient air TVOC online monitoring system of claim 4, wherein: and a flow sensor is further arranged between the exhaust port and the photoionization sensor, the MCU main control module is connected with the flow sensor, and the flow rate of the sampling pump is controlled according to the gas flow collected by the flow sensor so as to realize accurate air intake.
9. A novel ambient air TVOC on-line monitoring system according to claim 2 or 3, wherein: and a filter is arranged behind the air inlet and is used for filtering particles in the ambient air.
10. A novel ambient air TVOC on-line monitoring system according to claim 2 or 3, wherein: the sampling pump may also be disposed before the exhaust port.
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Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001074716A (en) * | 1999-08-31 | 2001-03-23 | Gl Sciences Inc | Method and apparatus for analysis of trace organic compound |
| US6320388B1 (en) * | 1999-06-11 | 2001-11-20 | Rae Systems, Inc. | Multiple channel photo-ionization detector for simultaneous and selective measurement of volatile organic compound |
| CN2620277Y (en) * | 2003-02-20 | 2004-06-09 | 上海精密科学仪器有限公司 | Gas flow circuit device for heat desorption apparatus |
| KR100654950B1 (en) * | 2005-11-08 | 2006-12-06 | 주식회사 케이엔알 | Multichannel Volatile Organic Compounds |
| CN201047833Y (en) * | 2007-06-22 | 2008-04-16 | 沈阳仪表科学研究院 | High voltage switch power distribution room SF6 environment monitoring device |
| JP2009257839A (en) * | 2008-04-14 | 2009-11-05 | Kajima Corp | Rapid analyzing system of voc and analyzing method of voc |
| CN201477082U (en) * | 2009-07-15 | 2010-05-19 | 武汉市天虹仪表有限责任公司 | Volatile Organic Compound Continuous Monitor |
| CN203672850U (en) * | 2013-12-31 | 2014-06-25 | 聚光科技(杭州)股份有限公司 | Adsorption/thermal desorption sample feeding device |
| CN105158053A (en) * | 2015-08-24 | 2015-12-16 | 成都翱宇环保科技有限公司 | Concentrator and analysis system for volatile organic compounds and usage method of analysis system |
| CN105388208A (en) * | 2015-12-14 | 2016-03-09 | 河南省建筑科学研究院有限公司 | PID-based air VOC monitoring machine and remote monitoring realization method thereof |
| CN106896179A (en) * | 2015-12-21 | 2017-06-27 | 中昊晨光化工研究院有限公司 | The online environment monitoring system and on-line monitoring method of a kind of fluorine chemical industry |
| KR20170092723A (en) * | 2016-02-03 | 2017-08-14 | (주) 에이스엔 | Ambient air monitoring system and method using sensor and gas chromatography |
| CN108195979A (en) * | 2018-02-26 | 2018-06-22 | 汉威科技集团股份有限公司 | Air VOCs on-line preconcentrations sampling device and method |
| CN207816936U (en) * | 2018-02-26 | 2018-09-04 | 郑州跃创电子科技有限公司 | A kind of multifunctional gas detection gas path switching device |
| CN209416973U (en) * | 2018-12-20 | 2019-09-20 | 汉威科技集团股份有限公司 | A kind of novel environmental air TVOC on-line monitoring system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10775354B2 (en) * | 2014-10-02 | 2020-09-15 | Brigham Young University | Autonomous ambient air sampling system for monitoring semi-volatile/non-volatile organic compounds |
-
2018
- 2018-12-20 CN CN201811562076.8A patent/CN109507276B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6320388B1 (en) * | 1999-06-11 | 2001-11-20 | Rae Systems, Inc. | Multiple channel photo-ionization detector for simultaneous and selective measurement of volatile organic compound |
| JP2001074716A (en) * | 1999-08-31 | 2001-03-23 | Gl Sciences Inc | Method and apparatus for analysis of trace organic compound |
| CN2620277Y (en) * | 2003-02-20 | 2004-06-09 | 上海精密科学仪器有限公司 | Gas flow circuit device for heat desorption apparatus |
| KR100654950B1 (en) * | 2005-11-08 | 2006-12-06 | 주식회사 케이엔알 | Multichannel Volatile Organic Compounds |
| CN201047833Y (en) * | 2007-06-22 | 2008-04-16 | 沈阳仪表科学研究院 | High voltage switch power distribution room SF6 environment monitoring device |
| JP2009257839A (en) * | 2008-04-14 | 2009-11-05 | Kajima Corp | Rapid analyzing system of voc and analyzing method of voc |
| CN201477082U (en) * | 2009-07-15 | 2010-05-19 | 武汉市天虹仪表有限责任公司 | Volatile Organic Compound Continuous Monitor |
| CN203672850U (en) * | 2013-12-31 | 2014-06-25 | 聚光科技(杭州)股份有限公司 | Adsorption/thermal desorption sample feeding device |
| CN105158053A (en) * | 2015-08-24 | 2015-12-16 | 成都翱宇环保科技有限公司 | Concentrator and analysis system for volatile organic compounds and usage method of analysis system |
| CN105388208A (en) * | 2015-12-14 | 2016-03-09 | 河南省建筑科学研究院有限公司 | PID-based air VOC monitoring machine and remote monitoring realization method thereof |
| CN106896179A (en) * | 2015-12-21 | 2017-06-27 | 中昊晨光化工研究院有限公司 | The online environment monitoring system and on-line monitoring method of a kind of fluorine chemical industry |
| KR20170092723A (en) * | 2016-02-03 | 2017-08-14 | (주) 에이스엔 | Ambient air monitoring system and method using sensor and gas chromatography |
| CN108195979A (en) * | 2018-02-26 | 2018-06-22 | 汉威科技集团股份有限公司 | Air VOCs on-line preconcentrations sampling device and method |
| CN207816936U (en) * | 2018-02-26 | 2018-09-04 | 郑州跃创电子科技有限公司 | A kind of multifunctional gas detection gas path switching device |
| CN209416973U (en) * | 2018-12-20 | 2019-09-20 | 汉威科技集团股份有限公司 | A kind of novel environmental air TVOC on-line monitoring system |
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| Publication number | Publication date |
|---|---|
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