CN204679877U - Pollution source VOC concentration and total emission volumn real-time monitoring system - Google Patents

Abstract

The utility model relates to a real-time monitoring system for VOC concentration and total emission of pollution sources, which comprises a waste gas sampling unit, a waste gas pretreatment unit, a VOC detection unit, a waste gas parameter measurement unit, a data processing unit, a blowback unit, a calibration unit, a communication unit and Central control unit, etc.; the output of the exhaust gas sampling unit is connected to the VOC detection unit through the exhaust gas pretreatment unit, the output of the exhaust gas parameter measurement unit and the VOC detection unit are connected to the data processing unit, and the output of the data processing unit is connected to the communication unit, the blowback unit and the calibration unit. The communication unit and the central control unit carry out data transmission through wireless or wired means. The utility model adopts a photoionization detector to detect the concentration and total amount of the characteristic pollutants discharged by the sewage discharge enterprises, and then monitors the VOC concentration and the total discharge amount in real time. Detection includes aromatics, ketones, aldehydes, alcohols, ammonia and amines, halogenated hydrocarbons, thiohydrocarbons, unsaturated hydrocarbons and many other compounds.

Description

Real-time monitoring system of VOC concentration and total emission of pollution sources

technical field

The utility model relates to a pollution monitoring system, in particular to a real-time monitoring system for VOC concentration and total discharge of pollution sources.

Background technique

VOC is the English abbreviation of volatile organic compounds (volatile organic compounds). In the general sense, VOC refers to command volatile organic compounds, while in the sense of environmental protection, VOC refers to a kind of active volatile organic compounds, that is, the kind that will cause harm. volatile organic compounds.

VOCs, or Volatile Organic Compounds, have a huge impact on human health. When the VOC in the living room reaches a certain concentration, people will have headache, nausea, vomiting, fatigue and other symptoms in a short time, and even convulsions or coma in severe cases. VOCs can damage the liver, kidneys, brain and nervous system, causing serious consequences such as memory loss.

At the same time, VOC is an important source of PM2.5. It is estimated that my country's VOC emissions are about 20 to 30 million tons. Therefore, in order to improve environmental quality, it is imperative to control VOC emissions. However, the current control of VOC emissions is still a weak link.

A large amount of VOC gas is emitted in the process of industrial production in my country. It is very important and necessary to detect and control the emission concentration and total amount of this type of gas. The commonly used detection method is on-site sampling plus laboratory analysis method. This method requires manual Sampling, laboratory analysis, and monitoring frequency of VOC emission enterprises are low, and it takes a long time to obtain the detection data, so it is impossible to monitor the VOC emission of enterprises in real time.

In addition, an effective VOC detection equipment needs to have the ability to analyze the active components of dozens of compounds to meet the needs of different detection objects. Therefore, its price is often in millions of yuan, and if this high price It is unimaginable and impossible to set up the testing equipment for the pollution detection of each pollutant enterprise. This also leads to the real-time monitoring of the concentration of characteristic pollutants and the total discharge of pollution sources. Unachievable.

Utility model content

The purpose of this utility model is to provide a real-time monitoring system for VOC concentration and total discharge of pollution sources, so as to solve the problem that the conventional detection method cannot achieve real-time monitoring of VOC emissions of enterprises.

The utility model is achieved in this way: a real-time monitoring system for VOC concentration and total discharge of pollution sources, including:

The exhaust gas sampling unit is respectively connected with the exhaust gas pretreatment unit and the blowback unit, and is used to sample, filter and heat the exhaust gas discharged from the measured point;

The exhaust gas pretreatment unit is respectively connected with the exhaust gas sampling unit, the VOC detection unit and the calibration unit, and is used to perform condensation and dehumidification treatment on the collected exhaust gas samples;

The VOC detection unit is respectively connected to the exhaust gas pretreatment unit and the data processing unit, and is used to detect the VOC concentration in the treated exhaust gas sample, and output the detection data to the data processing unit;

The exhaust gas parameter measurement unit is connected with the data processing unit and the blowback unit respectively, and is used to detect the temperature, pressure, flow and humidity of the exhaust gas discharged from the measured point, and output the detection data to the data processing unit;

The data processing unit is respectively connected with the VOC detection unit, the exhaust gas parameter measurement unit, the blowback unit and the communication unit, and is used to start the blowback unit on a regular basis, and perform data processing on the input detection data, and then convert the data The information is sent to the central control unit;

The blowback unit is respectively connected to the data processing unit, the exhaust gas sampling unit and the exhaust gas parameter measurement unit, and is divided into two circuits to perform the sampling gas circuit in the exhaust gas sampling unit and the exhaust gas parameter measurement unit. The measuring instruments are cleaned regularly by backflushing;

A communication unit, connected to the data processing unit, and connected to the central control unit by wire or wirelessly, for remotely sending the data information output by the data processing unit to the central control unit; and

The central control unit is connected with the communication unit by wire or wireless, and is used to receive the data information output by the data processing unit, so as to realize the real-time monitoring of the concentration and total emission of VOC in the exhaust gas discharged from the measured point .

The utility model also includes:

The calibration unit is connected to the exhaust gas pretreatment unit, and is used to periodically calibrate the measuring instruments in the VOC detection unit through the exhaust gas pretreatment unit.

The waste gas sampling unit is provided with a heating device, a filtering device and a cooling and dehumidifying device, the heating device heats the collected waste gas samples, and the cooling and dehumidifying device cools and dehumidifies the heated waste gas samples.

The VOC detection unit uses a photoionization detector to monitor the VOC in the collected exhaust gas, and the detection includes aromatics, ketones, aldehydes, ammonia and amines, halogenated hydrocarbons, thiohydrocarbons, unsaturated Hydrocarbons and alcohols, etc.; among them, aromatics are a series of compounds containing benzene rings, such as benzene, toluene, naphthalene, etc.; ketones and aldehydes are compounds containing C=O bonds, such as acetone; ammonia and amines are N-containing hydrocarbons, such as dimethylamine, etc.; unsaturated hydrocarbons such as olefins, etc.

The central control unit summarizes, analyzes and alarms the received data information, and converts the concentration and total discharge of VOCs into the concentration and concentration of characteristic pollutants discharged by the measured point (that is, the pollutant discharge enterprise). The total is recorded and displayed.

Although what the VOC detection unit among the present invention detects is the total amount of organic matter, because the organic matter discharged by a certain pollution source of each sewage enterprise is specific, therefore, the concentration and the VOC detected by the VOC detection unit detect The total discharge amount is actually the concentration and the total discharge amount of the characteristic pollutants discharged by the specific pollution source. In this way, the present invention does not need to configure large-scale equipment for distinguishing various polluting organic substances in the VOC detection unit, and only retains the concentration of VOC The measurement function of the detection and total discharge, combined with the analysis of the specific components of the measured gas at each measured point in advance, can clearly conclude that the concentration and total discharge of the characteristic pollutants at the measured point are actually what the VOC detection unit detects. VOC concentration detection and total emission. Like this, the present invention just can utilize the photoionization detector of price of only several thousand yuan to be able to finish the monitoring work of the concentration of characteristic pollutant and discharge amount, make to the concentration of the characteristic pollutant of pollution source and discharge amount real-time monitoring is possible. The key of the present invention just lies in this.

The utility model is characterized in that:

1. The exhaust gas sampling unit can heat the collected exhaust gas in the whole process, so as to effectively remove the interference of particles and moisture in the gas on the subsequent measurement, which is beneficial to improve the detection accuracy and reduce the measurement error;

2. The exhaust gas parameter measurement unit can simultaneously detect the temperature, pressure, humidity, flow rate and other parameters of the exhaust gas, and then monitor the total amount of VOC emissions in real time;

3. Set up the calibration unit, which can perform online real-time calibration of the measuring instruments in the exhaust gas parameter measurement unit to ensure the accuracy of the detection data;

4. The VOC detection unit uses a photoionization detector to detect organic gases, with many types of detection and high detection sensitivity;

5. According to user needs, the FID detector can be replaced.

The utility model adopts the condensation method to measure the flue gas/exhaust gas humidity, which has high measurement accuracy, easy maintenance for users, low operation cost of the whole set of equipment, real-time display of the minute average value of the monitoring data, and the monitoring data can be exported to an Excel file; the oxygen measurement uses oxidation Zirconium sensor with stable data, high accuracy and long life; the VOC monitoring method of PID\UV-DOAS\FTIR can be selected by the user, according to the user’s monitoring purpose and functional requirements; the embedded single-board computer can dynamically display the gas absorption curve .

Description of drawings

Fig. 1 is a system structure diagram of the utility model.

Fig. 2 is a system structure diagram of an embodiment of the utility model.

Fig. 3 is a partial structural schematic diagram of the site layout of the present invention.

Detailed ways

As shown in Figure 1, the utility model includes: an exhaust gas sampling unit, an exhaust gas pretreatment unit, a VOC detection unit, an exhaust gas parameter measurement unit, a data processing unit, a blowback unit, a calibration unit, a communication unit, and a central control unit; , the output terminal of the exhaust gas sampling unit is connected to the exhaust gas pretreatment unit, and the output terminal of the exhaust gas pretreatment unit is connected to the VOC detection sheet; the output terminals of the exhaust gas parameter measurement unit and the VOC detection unit are connected to the data input terminal of the data processing unit, and the data processing unit The data output terminal of the data processing unit is connected to the communication unit; the two control signal output terminals of the data processing unit, one is connected to the back blowing unit, and the other is connected to the calibration unit; the back blowing unit has two outputs, one of which is connected to the exhaust gas sampling unit, and the other is connected to the exhaust gas The parameter measurement unit; the output of the calibration unit is connected to the exhaust gas pretreatment unit; the communication unit performs data transmission with the central control unit through wireless or wired means.

The exhaust gas sampling unit includes a heating device, a filtering device, a cooling and dehumidifying device and a composite sampling pipeline (also known as "heat tracing pipeline"). The heating device heats the exhaust gas sample collected from the measured point, and the filtering device filters the exhaust gas sample. , the cooling and dehumidification device performs cooling and dehumidification treatment on the exhaust gas sample. The heating device and the filtering device can also be combined with the sampling head in the exhaust gas sampling unit to form a heating and filtering sampling head to simplify the structure.

A flue gas condensation and filtration device is provided in the exhaust gas pretreatment unit to perform condensation and dehumidification treatment on the collected and heated exhaust gas samples.

The VOC detection unit includes a photoionization detector (PID for short). The photoionization detector uses an ultraviolet lamp to ionize the sample gas to detect its concentration. When the sample molecules absorb high ultraviolet energy, the molecules are ionized into positive and negatively charged ions, which are sensed by the charge sensor and form a current signal. Only a small part of VOC molecules are ionized by ultraviolet light, so they can be combined into complete molecules after ionization for further analysis of samples. The VOC detection unit in the present invention can detect various compounds such as aromatics, ketones, aldehydes, ammonia and amines, halogenated hydrocarbons, thiohydrocarbons, unsaturated hydrocarbons and alcohols.

The exhaust gas parameter measurement unit includes an exhaust gas temperature measuring instrument, an exhaust gas pressure measuring instrument, an exhaust gas flow measuring instrument and an exhaust gas humidity measuring instrument, etc., which can detect the temperature, pressure, flow and humidity of the exhaust gas discharged from the measured point, and send the detection data to to the data processing unit.

The data processing unit is used to process the detection data input from the exhaust gas parameter measurement unit and the VOC detection unit respectively, and send the processed data information to the central control unit remotely through the communication unit.

The communication unit is a remote wireless communication module, which can establish wired or wireless communication with the central control unit, so as to remotely send the data information output by the data processing unit to the central control unit.

The backflush unit includes two independent backflush systems, which are used for regular backflush cleaning of the sampling gas path in the exhaust gas sampling unit and the measuring instruments in the exhaust gas parameter measurement unit.

The calibration unit is a calibration system for gas detection instruments, which is used for regular calibration of PID. The utility model connects the calibration unit to the VOC detection unit through the exhaust gas pretreatment unit, so that the PID can be calibrated after superimposing the error factors of the exhaust gas pretreatment unit, so that the calibration is more objective and the PID Calibration is more accurate.

The central control unit receives the data information output by the data processing unit through the communication unit, summarizes, analyzes and alarms the received data information, and converts the detected VOC concentration and total emission into the emission of the measured point The concentration and total amount of the characteristic pollutants in order to realize the real-time monitoring of the concentration and total amount of the characteristic pollutants in the exhaust gas discharged by the sewage enterprises.

Example

As shown in Figure 2, a kind of concrete realization mode of the present utility model is as follows:

As an exhaust gas sampling unit, the gaseous pollutant sampling unit is installed at the exhaust outlet of the sewage discharge enterprise to sample the flue gas. The flue gas pretreatment unit is used as an exhaust gas pretreatment unit to filter, condense and dehumidify the flue gas samples collected by the gaseous pollutant sampling unit. The flue gas flow controller is set at the output end of the flue gas pretreatment unit to control the flow of the collected flue gas samples, and then transport the flue gas samples to the input end of the VOC detector as the VOC detection unit. The output end of the VOC detector is connected to the data input end of the data acquisition and control system as a data processing unit.

The exhaust gas parameter measurement unit in this embodiment includes four working branches: the first is the working branch composed of the exhaust gas temperature transmitter and the exhaust gas temperature measuring instrument, and the second is the exhaust gas pressure transmitter and the exhaust gas pressure measuring instrument The working branch composed of the third road is the working branch composed of the exhaust gas flow transmitter and the exhaust gas flow measuring instrument, and the fourth road is the working branch composed of the exhaust gas humidity transmitter and the exhaust gas humidity measuring instrument; the four working branches The detection data output ends of the road are all connected to the data information input ends of the data acquisition and control system. The data information output end of the data acquisition and control system is connected to the communication unit, and the two control signal output ends of the data acquisition and control system are branched to the two control ends of the blowback unit. The output of the two high-pressure gas circuits of the backflush unit, one is connected to the gaseous pollutant sampling unit, and the sampling gas circuit in the gaseous pollutant sampling unit is regularly backflushed and cleaned; the other is connected to the exhaust gas pressure transmitter. The transmitter performs regular backflush cleaning of the exhaust gas pressure measuring instrument.

The data signal output end of the data acquisition and control system is connected to the remote communication system as the communication unit, and the remote communication system uploads the processed data information wirelessly (or wired) to the pollution source monitoring system as the central control unit. The pollution source monitoring system summarizes and analyzes the detection data information that is detected and transmitted back at the smoke exhaust outlet of the sewage discharge enterprise, and takes the detected VOC concentration and total emission as the concentration and total amount of characteristic pollutants discharged, and analyzes the pollutant discharge enterprises. The concentration and total emission of characteristic pollutants in the exhaust gas are monitored in real time, and the monitored data information can be displayed and printed, and an audible alarm can be issued when the monitored data exceeds the limit. The environmental authorities can connect the remote communication system through the data acquisition instrument to collect, analyze and summarize the monitoring data information.

The local structure of the site layout of this embodiment is shown in Figure 3. The sampling probe 2 is installed on the chimney 1 of the polluting enterprise (the point to be measured), and one end of the heating pipeline 3 is connected to the sampling probe 2, and the other end is connected to the VOC detection unit 9. At the input end, the first on-off valve 5 is connected to the heat mixing pipeline 3; the communication pipe of the second back blowing unit is connected to the heat mixing pipeline 3, and the second on-off valve 4 is connected to the communication pipe of the second back blowing unit , the second on-off valve 4 is a normally closed solenoid valve, its control end is connected to the data acquisition and control system, and the opening of the second on-off valve 4 is controlled by the data acquisition and control system, and the high-pressure gas in the high-pressure gas source can pass through the communication pipe to the The hot mixing line 3 is subjected to high-pressure backflushing to regularly clean the hot mixing line 3 . A third on-off valve 6 is connected to the connecting pipeline at the output end of the VOC detection unit 9, the third on-off valve 6 is a normally open solenoid valve, and the connecting pipeline is connected to the flue gas sampling pump for the subsequent exhaust gas pretreatment unit and exhaust gas parameters. A measuring unit (not shown) provides the collected flue gas. The collected flue gas is condensed and filtered by the exhaust gas pretreatment unit, and then sent to the exhaust gas parameter measurement unit for temperature, pressure, flow and humidity detection, and the detection data is output to the data acquisition and control system. Finally, the collected flue gas is exhausted to the outside through the exhaust pipe.

The VOC detection unit 9 is also connected with a standard gas inlet pipe and a standard gas outlet pipe for connecting the calibration unit, a fourth on-off valve 8 is connected on the calibration gas inlet pipe, and a fifth on-off valve 7 is connected on the calibration gas outlet pipe. , the fourth on-off valve 8 and the fifth on-off valve 7 are normally closed solenoid valves, the calibration unit provides standard gas, and the VOC detection unit 9 performs regular calibration accordingly to reduce detection errors.

The working principle of the utility model is that after the exhaust gas is collected and filtered by the exhaust gas sampling unit, it enters the exhaust gas pretreatment unit through the heat preservation and heating transmission of the mixing heat pipeline, and enters the VOC detection unit after condensation and water removal in the exhaust gas pretreatment unit. The VOC detection unit sends the detected VOC data to the data acquisition and control system. After the data is processed by the data acquisition and control system, it is then transmitted to the pollution source monitoring system through the wireless communication network or the Internet for display; at the same time, the exhaust gas parameter measurement unit real-time Measure parameters such as temperature, pressure, humidity and flow velocity of the exhaust gas. After the detection data is processed by the data acquisition and control system, it is sent to the pollution source monitoring system remotely to calculate the exhaust gas emission of the measured point. The two backflushing units automatically clean the sampling pipeline regularly, and the calibration unit regularly calibrates the measuring instruments to ensure the accuracy of the measurement data.

The main technical indicators of the real-time monitoring system of the present invention are as follows:

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Claims (5)

1. pollution source VOC concentration and a total emission volumn real-time monitoring system, is characterized in that, include:

Waste gas sampling unit, connects with waste gas pretreatment unit and blowback unit respectively, samples for the waste gas discharged measured point, filter and heats;

Waste gas pretreatment unit, connects with described waste gas sampling unit, VOC detecting unit and alignment unit respectively, for carrying out dehumidification by condensation process to the waste gas sample gathered;

VOC detecting unit, connects with described waste gas pretreatment unit and data processing unit respectively, for detecting the VOC concentration in waste gas sample after treatment, and detection data is outputted to data processing unit;

Exhaust gas parameters measuring unit, connects with data processing unit and blowback unit respectively, and the waste gas for discharging measured point carries out the detection of temperature, pressure, flow and humidity, and detection data are outputted to data processing unit;

Data processing unit, connect with described VOC detecting unit, described exhaust gas parameters measuring unit, blowback unit and communication unit respectively, for regularly starting the action of blowback unit, and data processing being carried out to the detection data of input, then data message being sent to centralized control unit;

Blowback unit, connect with described data processing unit, described waste gas sampling unit and described exhaust gas parameters measuring unit respectively, point two-way carries out regular blowback cleaning respectively to the surveying instrument in the sampling gas circuit in described waste gas sampling unit and described exhaust gas parameters measuring unit;

Communication unit, connects with described data processing unit, and is connected with centralized control unit by wired or wireless mode, and the data message for being exported by described data processing unit is long-range is sent to centralized control unit; And

Centralized control unit, is connected with described communication unit by wired or wireless mode, for receiving the data message exported by data processing unit, to realize the concentration of VOC in measured point institute discharging waste gas and the real-time monitoring of total emission volumn.

2. pollution source VOC concentration according to claim 1 and total emission volumn real-time monitoring system, is characterized in that, also include:

Alignment unit, connects with described waste gas pretreatment unit, for carrying out regular calibration by described waste gas pretreatment unit to the surveying instrument in described VOC detecting unit.

3. pollution source VOC concentration according to claim 1 and 2 and total emission volumn real-time monitoring system, it is characterized in that, heating arrangement, filtration unit and cooling and dehumidifying device is provided with in described waste gas sampling unit, described heating arrangement heats the waste gas sample gathered, and described cooling and dehumidifying device carries out cooling and dehumidifying process to the waste gas sample after heating.

4. pollution source VOC concentration according to claim 1 and 2 and total emission volumn real-time monitoring system, it is characterized in that, described VOC detecting unit uses photoionization detector to monitor the VOC in gathered waste gas, detects and comprise aromatics, ketone, aldehydes, ammonia and amine, halogenated hydrocarbon, sulfo-hydro carbons, unsaturated hydro carbons and alcohols.

5. pollution source VOC concentration according to claim 1 and 2 and total emission volumn real-time monitoring system, it is characterized in that, described centralized control unit gathers received data message, analyze and overload alarm, and the concentration of VOC wherein and total emission volumn can be converted into the concentration of the characteristic contamination of measured point discharge and total amount is recorded and shows.