System and method for online monitoring of domestic waste odor

Abstract

The present invention provides a system and method for online monitoring of domestic waste odor, including: a malodorous gas pretreatment module, a sensor module, a gas path transmission module, a communication module and an industrial control module; the sensor module includes an air chamber, a sensor array, and a conditioning circuit; the gas path transmission module includes a solenoid valve, a flow meter, and an air pump; the communication module includes a downlink 485 communication terminal, an Ethernet port, a switch, and a USB interface; the industrial control module includes an uplink 485 communication terminal, a 24V power supply, a zero gas control, an antenna, a 4G module, and a display screen. Based on the existing environmental monitoring technology, the present invention solves the problems of heat concentration in the sensor air chamber and uneven airflow distribution, and realizes real-time monitoring of domestic waste odor.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection technology, and in particular to an online monitoring system and method for domestic waste odor. Background Art

[0002] Benzene, vinyl chloride and 1,3-butadiene present in malodorous gases are carcinogens, while chloroform, carbon tetrachloride and styrene are also potential carcinogens. In addition, many volatile organic compounds can cause allergies and asthma and are negatively correlated with lung function; on the other hand, malodorous gas emissions are inseparable from environmental risks. Related studies have shown that emissions of chlorofluorocarbons and halogenated hydrocarbons can lead to ozone depletion and global warming, and some alkanes and aromatic hydrocarbons combine with nitrogen oxides in the atmosphere to form secondary air pollutants.

[0003] Odor monitoring equipment is a complex odor identification device. Its odor identification process not only involves gas sensor technology, but is also closely related to many fields such as multi-information data fusion and optimization, applied mathematics, information processing technology, computer software, etc.

[0004] Patent document CN107180144A (application number: CN201710465436.1) discloses a comprehensive online risk monitoring and early warning system for a domestic waste landfill, including a risk monitoring system, a multi-field coupled simulation system and an early warning system. The risk monitoring system is connected to the multi-field coupled simulation system, and the multi-field coupled simulation system is connected to the early warning system. The multi-field coupled simulation system establishes a comprehensive risk model of the landfill based on the monitoring results of the risk monitoring system by processing data. When the risk characteristic parameters exceed the threshold, the early warning system is immediately activated.

[0005] The sensor arrays of several types of electronic nose systems that are currently commercialized mostly include highly sensitive metal oxide sensors (MOS), highly selective electrochemical sensors (EC), and photoion sensors (PID) that are more sensitive to VOCs between n-hexane and n-hexadecane. In terms of their detection principles: (1) MOS sensors are made of metal oxides and are easily interacted with target gases to produce surface adsorption reactions, causing changes in conductivity, volt-ampere characteristics, or surface potential characterized by carrier movement. (2) Most flammable or toxic and harmful gases have certain electrochemical activity and can be reduced or oxidized by EC sensors. Depending on the reaction conditions, the gas composition and gas concentration can be distinguished. (3) PID sensors use ion recognition materials fixed on the sensitive membrane to selectively bind to the ions being sensed, thereby causing changes in membrane potential or membrane current to achieve the purpose of gas detection. Summary of the invention

[0006] In view of the defects in the prior art, the object of the present invention is to provide a system and method for online monitoring of domestic waste odor.

[0007] The domestic waste odor online monitoring system provided by the present invention comprises: an odor gas pretreatment module, a sensor module, a gas path transmission module, a communication module and an industrial control module;

[0008] The malodorous gas pre-processing module includes a scene trigger and a malodorous gas front-end processing instrument;

[0009] The scene trigger has a built-in concentration database of domestic waste odor scenes, and a scene trigger button is installed on its shell for selecting a specified detection scene. An odor level display panel is provided below the trigger button, and the concentration distribution of ammonia, hydrogen sulfide, methyl mercaptan, and benzene series in the database and the corresponding odor OU value range in the current scene are displayed above the button;

[0010] One end of the malodorous gas front-end processing instrument is connected to a scene trigger, and the other end is connected to a sampling port, and it selects to enter a gas dilution or enrichment state according to the scene trigger;

[0011] One end of the communication module is connected to the sensor module, and the other end is connected to the industrial control module;

[0012] The industrial control module is the master control module of the entire system, which is respectively connected to the odor gas pretreatment module, the sensor module, the gas path transmission module and the communication module, and controls the sensor module and the gas path transmission module through the communication module to perform odor detection and gas transportation processing.

[0013] Preferably, the sensor module comprises: an air chamber, a sensor array and a conditioning circuit;

[0014] The air chamber is sealed and constant temperature, and the inner wall is coated with a Teflon protective layer. The sensor array inside is connected to the conditioning circuit board, one end has three gas inlets, and the other end is connected to the flow meter through the exhaust port at the center. When the sensor array is in working state, it only heats up and does not cool down.

[0015] Preferably, the sensor array includes 3 electrochemical sensors, 2 metal oxide sensors and 1 photoion sensor, the electrochemical sensors are used to detect ammonia, hydrogen sulfide and methyl mercaptan, respectively, the metal oxide sensors are used to detect TVOC and benzene series, and the photoion sensor is used to convert the odor OU value.

[0016] Preferably, the conditioning circuit includes a signal separation circuit, a signal amplification circuit and an AD conversion circuit.

[0017] Preferably, the gas transport module is composed of a zero gas passage and a waste gas passage in parallel, the zero gas passage is composed of an air inlet, a solenoid valve, a flow meter, an air pump, and a zero gas port in series, and the waste gas passage is composed of an inlet, a sensor module, an air pump, a flow meter in series, and an exhaust port in series.

[0018] Preferably, the air inlet is an air hole arranged on the circular wall of the air chamber with a diameter of 6 mm. Three Teflon tubes with an outer diameter of 6 mm and an inner diameter of 4 mm are connected to a four-way joint. The other end of the four-way joint is connected to a Teflon tube for external air intake or connected to a gas distribution tank for gas calibration.

[0019] Preferably, the exhaust port is connected to the flow meter by a Teflon tube, and the exhaust port is located at the top of the conical wall of the air chamber;

[0020] The gas to be tested passes through the four-way joint and flows into the air chamber through the air inlet at the same time, contacts the six sensors, and is discharged from the exhaust port.

[0021] Preferably, the communication module includes a downlink 485 communication terminal, an Ethernet port and a USB interface;

[0022] The downstream 485 communication terminal is connected to the conditioning circuit, the Ethernet port is connected to the industrial control module, and the USB interface is connected to the communication module;

[0023] View historical logs on the PC through the Ethernet port and save data to a USB flash drive through the USB interface.

[0024] Preferably, the industrial control module includes an uplink 485 communication terminal, an antenna, a 4G module and a display screen;

[0025] The antenna, 4G module and display screen are connected to the Ethernet port, and the uplink 485 communication terminal is connected to the industrial control module;

[0026] Initialize and configure the industrial control system through the 4G module, antenna and display screen.

[0027] According to the method for online monitoring of domestic waste odor provided by the present invention, the following steps are performed:

[0028] Step 1: Turn on the power to preheat the sensor, and then use the computer to record the sensor's response state as the initial value;

[0029] Step 2: Select the scene switcher state according to the detection environment;

[0030] Step 3: The odorous gas reaches the injection port through the dilution module or enrichment module of the odorous gas front-end processor and enters the sensor gas chamber. The analog signal generated by the sensor array is converted into a multi-dimensional digital signal through the conditioning circuit. The signal value is read by the downstream 485 terminal, and the real-time concentration value of the sensor is obtained by the upstream 485 terminal and transmitted to the client in real time;

[0031] Step 4: Clean air enters the sensor air chamber from the zero air path to clean the sensor. After the sensor becomes stable again, perform the next test.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention proposes a sensor air chamber with three inlets and one outlet, wherein the three inlets are arranged in an isosceles triangle, and the outlet is located on the midline of the isosceles triangle, which can ensure simultaneous air intake; six gas sensors are evenly arranged in a ring shape in the sensor air chamber, and an inlet is arranged at the center of every two sensors, which effectively solves the problems of uneven sensor gas contact area, uneven contact time, and uneven airflow diffusion, and the sensor array arranged in a ring solves the problems of excessive power consumption and unstable detection accuracy caused by excessive heat concentration in the sensor module;

[0034] (2) The malodorous gas front-end treatment device proposed in the present invention is composed of a malodorous gas enrichment module and a dilution module connected in parallel after a scene trigger. It has the performance advantages of both modules and can automatically compare the database content according to the scene trigger instruction and match the corresponding malodorous gas pretreatment mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0036] Figure 1 It is a structural diagram of the online monitoring system for domestic waste odor;

[0037] Figure 2 This is a structural diagram of a system for pre-treatment of variable malodorous gases in a typical scenario;

[0038] Figure 3a is the internal cross-sectional view of the air chamber. Figure 3b is a side view of the air chamber;

[0039] Figure 4a This is the air chamber cleaning stage. Figure 4b It is the injection stage;

[0040] Figure 5 This is a flow chart of domestic waste odor detection based on odor gas front-end treatment instrument;

[0041] Figure 6 It is a signal transmission flow chart based on the industrial control board;

[0042] In the figure, 1-display screen; 2-downlink 485 communication terminal; 3-air chamber; 4-conditioning circuit; 5-solenoid valve; 6-first flow meter; 7-zero gas control; 8-antenna; 9-first air pump; 10-second flow meter; 11-second air pump; 12-4G module; 13-Ethernet port; 14-USB port; 15-24V power supply; 16-uplink 485 communication terminal; 17-switch; I-sensor module; II-communication module; III-gas transport module; IV-industrial control module; A-1, A-4, A-7 are air inlets; A-2, A-3, A-5, A-6, A-8, A-9 are sensors; B-10 is exhaust port; III-1 is zero gas path; III-2 is exhaust gas path; 2a is scene trigger, 2b is odorous gas front-end pre-processor. DETAILED DESCRIPTION

[0043] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0044] Example:

[0045] like Figure 1 As shown, the online monitoring system for domestic waste odor proposed by the present invention includes: a sensor module I, a communication module II, a gas path transmission module III and an industrial control module IV;

[0046] The sensor module I is interconnected with the communication module II, the communication module II is interconnected with the industrial control module IV, and the gas path transmission module III is connected to the sensor module I through a DuPont line;

[0047] The gas path transmission module III and the industrial control module IV realize the gas path control;

[0048] The sensor module I and the communication module II enable the computer to edit and configure local files;

[0049] The sensor module I and the industrial control module IV realize the acquisition of sensor concentration.

[0050] The sensor module 1 includes an air chamber 3, a sensor array, and a conditioning circuit 4; the sensor array is arranged on the conditioning circuit 4 and sealed in the air chamber 3;

[0051] The gas path delivery module III is composed of a zero gas path III-1 and an exhaust gas path III-2, and includes a solenoid valve 5, a first flow meter 6 and a second flow meter 10, a first air pump 9 and a second air pump 11.

[0052] The solenoid valve 5, the first flow meter 6, and the first air pump 9 are connected to the zero gas path III-1 through an air pipe;

[0053] The second flow meter 10 and the second air pump 11 are connected to the exhaust gas path III-2 through an air pipe;

[0054] The zero gas path III-1 is connected to the air inlet of the air chamber, and the exhaust gas path III-2 is connected to the exhaust port;

[0055] The solenoid valve 5, the first flow meter 6, the second flow meter 10, the first air pump 9 and the second air pump 11 are connected to the conditioning circuit 4 through DuPont lines.

[0056] The communication module II includes a downstream 485 communication terminal 2, an Ethernet port 13, a switch 17, and a USB interface 14; the downstream 485 communication terminal 2 is connected to the conditioning circuit 4, and the Ethernet port 13 is connected to the industrial control module IV; the historical log is viewed on the PC side through the Ethernet port 13, and the data is stored in a USB flash drive through the USB interface 14;

[0057] The industrial control module IV includes an uplink 485 communication terminal 16, a 24V power supply 15, a zero gas control (232 rpm relay output) 7, an antenna 8, a 4G module 12 and a display screen 1; the 4G module 12 is connected to the Ethernet port 13, and the uplink 485 communication terminal 16 is connected to the industrial control module IV, and the initialization configuration of the industrial control system is realized through the 4G module 12, the antenna 8 and the display screen 1.

[0058] like Figure 3a , the air inlets A-1, A-4, and A-7 are air holes arranged on the circular wall of the air chamber, with a diameter of 6 mm. They can be connected to a four-way joint by connecting three Teflon tubes with an outer diameter of 6 mm and an inner diameter of 4 mm. The other end of the four-way joint is connected to a Teflon tube for external air intake or connected to a gas distribution tank for gas calibration; A-2, A-3, A-5, A-6, A-8, and A-9 are six sensors placed on the conditioning circuit board inside the air chamber, arranged in a circular shape;

[0059] like Figure 3b , B-10 is the exhaust port, which is connected to the second flowmeter 10 with a Teflon tube. The exhaust port is located at the top of the conical wall of the air chamber; the gas to be measured flows from the air inlet through the four-way joint, and flows into A-1, A-4, and A-7 at the same time into the air chamber, contacts the six sensors, and is discharged from B-10.

[0060] When the air path delivery module III is in the flow direction shown in state b, it is the sampling stage, and when it is in the flow direction shown in state a, it is the sensor air chamber cleaning stage; in state a, the second air pump 11 inhales the mixed gas, and the first air pump 9 pumps the filtered clean air to the air chamber to dilute the gas to be detected. In state b, the high flow rate zero gas reverses the air flow to clean the air chamber.

[0061] like Figure 4a , is state a, the air chamber cleaning stage;

[0062] The second air pump 11 sucks the mixed air through the air chamber;

[0063] The first air pump 9: adds clean air into the air chamber to dilute the gas to be tested;

[0064] The flow rate of the first air pump 9 is higher (higher than state a), and the air flow at the air chamber inlet is reversed to start emptying and cleaning the sensor air chamber.

[0065] like Figure 4b , is state b, injection stage;

[0066] The flow rate of the first air pump 9 is greater than the flow rate of the second air pump 11, and the difference between the flow rates of the zero gas path and the waste gas path per unit time is the injection flow rate of the air chamber per unit time.

[0067] like Figure 5 , a complete domestic waste odor detection process of the present invention is as follows:

[0068] (1) Turn on the power supply, and preheat the sensor (sensor array, MOS sensor, the measured value is more reliable after preheating (BTEX, TVOC sensor) for 1 hour. The computer records the response state of the sensor at this time as the initial value;

[0069] (2) Selecting the scene switcher state according to the detection environment;

[0070] (3) The malodorous gas reaches the sampling port from the gas dilution and enrichment instrument and enters the sensor gas chamber 3. The analog signal generated by the sensor array is converted into a multi-dimensional digital signal by the conditioning circuit 4. The signal value is read by the downstream 485 terminal 2. The real-time concentration value of the sensor can be obtained by the upstream 485 terminal and transmitted to the client in real time;

[0071] (4) Clean air enters the sensor air chamber from the zero air path for 1 minute. After the sensor becomes stable again, the next test can be carried out.

[0072] (5) During automatic monitoring, repeat the above steps.

[0073] like Figure 6, which is a signal flow chart based on the industrial control board, including: the sensor array transmits the gas signal and the analog signal to the sensor conditioning circuit, obtains the voltage / current signal and the analog signal, performs A / D conversion, obtains the digital signal, and then transmits it to the PC.

[0074] Those skilled in the art know that, in addition to implementing the system, device and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be considered as structures within the hardware component; the modules for implementing various functions can also be considered as both software programs for implementing the method and structures within the hardware component.

[0075] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. An online monitoring system for domestic waste odor, characterized in that: include: Malodorous gas pretreatment module, sensor module, gas transmission module, communication module and industrial control module; The malodorous gas pre-processing module includes a scene trigger and a malodorous gas front-end processing instrument; The scene trigger has a built-in concentration database of domestic waste odor scenes, and a scene trigger button is installed on its shell for selecting a specified detection scene. An odor level display panel is provided below the trigger button, and the concentration distribution of ammonia, hydrogen sulfide, methyl mercaptan, and benzene series in the database and the corresponding odor OU value range in the current scene are displayed above the button; One end of the malodorous gas front-end processing instrument is connected to a scene trigger, and the other end is connected to a sampling port, and it selects to enter a gas dilution or enrichment state according to the scene trigger; One end of the communication module is connected to the sensor module, and the other end is connected to the industrial control module; The industrial control module is the master control module of the entire system, which is connected to the odor gas pretreatment module, the sensor module, the gas path transmission module and the communication module respectively, and controls the sensor module and the gas path transmission module to perform odor detection and gas transportation processing through the communication module; The gas transport module is formed by connecting a zero gas passage in parallel with an exhaust gas passage, wherein the zero gas passage is formed by connecting an air inlet, a solenoid valve, a flow meter, an air pump, and a zero gas port in series, and the exhaust gas passage is formed by connecting an inlet, a sensor module, an air pump, a flow meter in series, and an exhaust port in series; The air inlet is an air hole arranged on the circular wall of the air chamber, with a diameter of 6 mm, and is connected to a four-way joint by connecting three Teflon tubes with an outer diameter of 6 mm and an inner diameter of 4 mm. The other end of the four-way joint is connected to a Teflon tube for external air intake or connected to a gas distribution tank for gas calibration; The exhaust port is connected to the flow meter by a Teflon tube, and the exhaust port is located at the top of the conical wall of the air chamber; The gas to be tested passes through the four-way joint and flows into the air chamber through the air inlet at the same time, contacts the six sensors, and is discharged from the exhaust port.

2. The online monitoring system for domestic waste odor according to claim 1 is characterized in that: The sensor module includes: an air chamber, a sensor array and a conditioning circuit; The air chamber is sealed and constant temperature, and the inner wall is coated with a Teflon protective layer. The sensor array inside is connected to the conditioning circuit board, one end has three gas inlets, and the other end is connected to the flow meter through the exhaust port at the center. When the sensor array is in working state, it only heats up and does not cool down.

3. The online monitoring system for domestic waste odor according to claim 2 is characterized in that: The sensor array includes 3 electrochemical sensors, 2 metal oxide sensors and 1 photoion sensor. The electrochemical sensors are used to detect ammonia, hydrogen sulfide and methyl mercaptan respectively, the metal oxide sensors are used to detect TVOC and benzene series, and the photoion sensor is used to convert the odor OU value.

4. The online monitoring system for domestic waste odor according to claim 2 is characterized in that: The conditioning circuit includes a signal separation circuit, a signal amplification circuit and an AD conversion circuit.

5. The online monitoring system for domestic waste odor according to claim 2 is characterized in that: The communication module includes a downlink 485 communication terminal, an Ethernet port and a USB interface; The downstream 485 communication terminal is connected to the conditioning circuit, the Ethernet port is connected to the industrial control module, and the USB interface is connected to the communication module; View historical logs on the PC through the Ethernet port and save data to a USB flash drive through the USB interface.

6. The online monitoring system for domestic waste odor according to claim 5 is characterized in that: The industrial control module includes an uplink 485 communication terminal, an antenna, a 4G module and a display screen; The antenna, 4G module and display screen are connected to the Ethernet port, and the uplink 485 communication terminal is connected to the industrial control module; Initialize and configure the industrial control system through the 4G module, antenna and display screen.

7. A method for online monitoring of domestic waste odor, characterized in that: Using the online monitoring system for domestic waste odor according to any one of claims 1 to 6, the following steps are performed: Step 1: Turn on the power to preheat the sensor, and then use the computer to record the sensor's response state as the initial value; Step 2: Select the scene switcher state according to the detection environment; Step 3: The odorous gas reaches the sampling port through the gas dilution and enrichment instrument, and enters the sensor gas chamber. The analog signal generated by the sensor array is converted into a multi-dimensional digital signal through the conditioning circuit. The signal value is read by the downstream 485 terminal, and the real-time concentration value of the sensor is obtained by the upstream 485 terminal and transmitted to the client in real time; Step 4: Clean air enters the sensor air chamber from the zero air path to clean the sensor. After the sensor becomes stable again, perform the next test.

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