On-line monitoring system and method of condensable particulate matters in flue gas of ultra-low emission coal-fired power plant

Abstract

The present application relates to a kind of online monitoring system and method of condensable particulate in flue gas of coal-fired power plant ultra-low emission, belong to the technical field of flue gas particulate monitoring of coal-fired power plant ultra-low emission.The monitoring system includes flue gas pretreatment zone, monitoring condensing zone and tail gas treatment zone;Flue gas pretreatment zone collects the flue gas to be measured and pretreats the flue gas to be measured;Monitoring condensing zone carries out condensing treatment to the flue gas to be measured after pretreatment, makes condensable particulate in the flue gas to be measured condense, and calculates the mass of condensable particulate;Tail gas treatment zone is discharged into atmosphere after purifying the gas discharged in monitoring condensing zone;The system also includes control module and atmospheric temperature and humidity sensor adjustment monitoring condensing zone's temperature and humidity, so that condensable particulate in the flue gas to be measured condenses and settles.The present application can monitor condensable particulate in flue gas in real time online, provides certain data reference for environmental protection monitoring.

Description

Technical Field

[0001] This invention belongs to the field of particulate matter monitoring technology in ultra-low emission flue gas of coal-fired power plants, and relates to an online monitoring system and method for condensable particulate matter in ultra-low emission flue gas of coal-fired power plants. Background Technology

[0002] After ultra-low emission retrofitting, the flue gas from coal-fired power plants is in a high-temperature and high-humidity state, with a temperature of 50-60℃. It mainly contains water, filterable particulate matter, volatile organic compounds (VOCs), and nitrogen sulfides. When it enters the atmosphere, due to changes in temperature and humidity, some nitrogen sulfides, ammonia, hydrogen chloride, and VOCs will condense into nuclei to produce condensable particulate matter. The resulting PM2.5 is a primary pollutant that has a great impact on human health and the environment. Currently, there is no equipment for online monitoring of condensable particulate matter. At present, the detection of condensable particulate matter is mainly carried out using the impact condensation method and the dilution condensation method. This technology has the following disadvantages: (1) The measurement process is cumbersome and involves sampling and detection; (2) The detection time is long and the consumables are numerous. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a monitoring system and method for condensable particulate matter in ultra-low emission flue gas of coal-fired power plants, which can monitor the mass of condensable particulate matter in real time online.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] Option 1: An online monitoring system for condensable particulate matter in ultra-low emission flue gas from a coal-fired power plant, comprising a flue gas pretreatment zone 1, a monitoring condensation zone 2, and a tail gas treatment zone 3 connected in sequence. The flue gas pretreatment zone 1 collects and pre-treats the flue gas to be tested; the monitoring condensation zone 2 condenses the pre-treated flue gas to cause the condensable particulate matter in the flue gas to condense and settle, and calculates the mass of the condensable particulate matter; the tail gas treatment zone 3 purifies the gas discharged from the monitoring condensation zone 2 before releasing it into the atmosphere, and also provides gas flow power.

[0006] The system also includes a control module and an atmospheric temperature and humidity sensor. The control module adjusts the temperature and humidity of the monitoring condensation zone 2 based on the atmospheric temperature and humidity collected by the atmospheric temperature and humidity sensor, so that the condensable particulate matter in the flue gas to be tested condenses and settles.

[0007] Optionally, the flue gas pretreatment zone includes a sampling gun 4, a heater 5, a high-efficiency filter 7, and a high-performance dehumidification membrane 8 connected in sequence; the heater 5 is used to heat the flue gas to be tested to above the dew point temperature; the high-efficiency filter 7 is used to filter filterable particulate matter in the flue gas to be tested; and the high-performance dehumidification membrane 8 is used to absorb moisture in the flue gas to be tested. The sampling gun, heater, high-efficiency filter, and high-performance dehumidification membrane are all wrapped with high-temperature resistant heat tracing pipelines.

[0008] Optionally, the monitoring condensation zone 2 includes a gas mass flow meter I9, a condensation chamber 10, a glass fiber filter membrane and a high-performance dehumidification membrane 11, a flow regulating valve 12, and a gas mass flow meter II 13 connected in sequence. The gas mass flow meter I9 is ​​used to detect the mass flow rate and velocity of the flue gas to be tested; the condensation chamber 10 is used to cause condensable particulate matter in the flue gas to condense and settle; the glass fiber filter membrane and the high-performance dehumidification membrane 11 are used to trap condensed but unsettled particulate matter; the gas mass flow meter II 13 is used to detect the mass flow rate and velocity of the flue gas after condensation treatment; and the flow regulating valve 12 is used to regulate the velocity of the flue gas at the gas mass flow meter.

[0009] Gas mass flow meter I9, flow regulating valve 12, and gas mass flow meter II13 are all connected to the control module.

[0010] Optionally, the condensation chamber includes a semiconductor cooling chip 16, an ultrasonic oscillating atomizer 17, and an organic adsorption layer 18. The semiconductor cooling chip and the ultrasonic oscillating atomizer are respectively connected to a control module, and under the control of the control module, the flue gas to be tested in the condensation chamber is condensed. The organic adsorption layer is used to absorb condensable particulate matter that settles during condensation.

[0011] Optionally, the exhaust gas treatment zone 3 includes a gas purifier 14 and a vacuum pump 15. The gas purifier purifies the flue gas discharged from the monitoring and condensation zone, and the vacuum pump provides power for the gas flow.

[0012] Option 2: An online monitoring method for condensable particulate matter based on the online monitoring system described in Option 1. This method uses a high-efficiency filter 7 and a high-performance dehumidification membrane 8 to remove filterable particulate matter and moisture from the flue gas to be tested. Then, the mass flow rate Q1 and velocity V1 of the flue gas to be tested before condensation are recorded by a gas mass flow meter I9. The flue gas to be tested condenses and settles in the condensation chamber 10. After the condensable particulate matter is absorbed and condensed by the organic adsorption layer 18, the glass fiber filter membrane, and the high-performance dehumidification membrane 11, the remaining flue gas flows through a gas mass flow meter II13. The gas mass flow meter II13 records the mass flow rate Q2 and velocity V2 of the flue gas after condensation.

[0013] This method simultaneously controls the flow rate of flue gas through the flow regulating valve 12, so that the flue gas flow rates at gas mass flow meter I9 and gas mass flow meter II13 are equal, and then calculates the mass of condensable particulate matter in the flue gas to be tested based on the law of conservation of mass.

[0014] The beneficial effects of this invention are as follows: This invention achieves the condensation and sedimentation of condensable particulate matter through a semiconductor cooling chip and an ultrasonic oscillating sprayer, and then records the flow rate and velocity of the flue gas before and after condensation through two gas mass flow meters. Based on the law of conservation of mass, the mass of condensable particulate matter in the flue gas to be tested can be calculated. It has the characteristics of real-time online monitoring and can quickly obtain information on the condensable particulate matter in the flue gas to be tested, providing certain data references for environmental monitoring.

[0015] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0017] Figure 1 This is a schematic diagram of the structure of the online monitoring system for condensable particulate matter of the present invention;

[0018] Figure 2 Here is a structural diagram of the condenser chamber;

[0019] Figure 3 This is a circuit diagram of the control module;

[0020] Figure 4 This is a logic block diagram for monitoring the quality of condensable particulate matter.

[0021] Figure reference numerals: 1-Flue gas pretreatment zone; 2-Monitoring condensation zone; 3-Tail gas treatment zone; 4-Sampling gun; 5-Heater; 6-High-temperature heat tracing pipeline; 7-High-efficiency filter; 8-High-performance dehumidification membrane; 9-Gas mass flow meter I; 10-Condensation chamber; 11-Glass fiber filter membrane and high-performance dehumidification membrane; 12-Flow regulating valve; 13-Gas mass flow meter II; 14-Gas purifier; 15-Vacuum pump; 16-Semiconductor cooling chip; 17-Ultrasonic oscillating sprayer; 18-Organic adsorption layer; 19-Outer shell. Detailed Implementation

[0022] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0023] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] like Figure 1 The image shows an online monitoring system for condensable particulate matter in ultra-low emission flue gas from a coal-fired power plant. The system includes a flue gas pretreatment zone 1, a monitoring and condensation zone 2, an exhaust gas treatment zone 3, an ambient temperature and humidity sensor, and a control module.

[0026] The flue gas pretreatment zone 1 includes a sampling gun 4, a heater 5, a high-efficiency filter 7, and a high-performance dehumidification membrane 8 connected in sequence. The sampling gun 4 is equipped with a high-temperature resistant sampling probe to prevent water vapor condensation on the probe surface and corrosion by corrosive substances. The heater 5 has stable temperature control performance, ensuring the flue gas heating temperature is higher than the dew point temperature of condensable particulate matter. The high-efficiency filter 7 filters filterable particulate matter and has high-temperature resistance. The high-performance dehumidification membrane 8 absorbs moisture from the flue gas without reacting with other gas components and requires periodic replacement. All components in the flue gas pretreatment zone 1 are encased in high-temperature resistant heat tracing pipelines 6 to prevent heat loss that could cause the temperature to drop below the dew point temperature of condensable particulate matter, thus preventing pipeline blockage.

[0027] The monitoring condensation zone 2 includes a gas mass flow meter I9, a condensation chamber 10, a glass fiber filter membrane and a high-performance dehumidification membrane 11, a flow regulating valve 12, and a gas mass flow meter II 13 connected in sequence. The condensation chamber 10 includes a semiconductor cooling chip 16, an ultrasonic oscillating sprayer 17, an organic adsorption layer 18, and a housing 19, such as... Figure 2 As shown. Gas mass flow meter I9 displays the current gas mass flow rate and velocity within the pipe and transmits the data signal to the control module via circuitry. A thermoelectric cooler 16 and an ultrasonic oscillating sprayer 17 are located at the top of the condensing chamber 10. The thermoelectric cooler 16 is connected to the control module via an electrical signal. Based on data feedback from the ambient temperature and humidity sensor, the control module, in conjunction with the ultrasonic oscillating sprayer, maintains the condensing chamber 10 at the same temperature and humidity as the atmosphere. An organic adsorption layer 18 is located at the bottom of the condensing chamber 10 and has the function of timely adsorbing moisture and VOCs condensates. The thermoelectric cooler, ultrasonic oscillating sprayer, and organic adsorption layer are encased in a shell 19 made of a material with good thermal conductivity. The flow regulating valve 12 is controlled by the control module, and its adjustment is based on the flow rate of gas mass flow meter I, ensuring that the flow rates of the two gas mass flow meters are equal.

[0028] The flue gas inlet and outlet ends of the condenser chamber 10 have the same diameter but a height difference. At the flue gas outlet end, there is a glass fiber filter membrane and a high-performance dehumidification membrane, which prevent suspended matter from escaping the condenser chamber. The high-performance dehumidification membrane absorbs moisture, does not react with other gas components, and requires periodic replacement.

[0029] The control module uses an MCU control unit. Gas mass flow meter I, a thermoelectric cooler, an ultrasonic oscillating sprayer, gas mass flow meter II, an ambient temperature and humidity sensor, and a flow control valve are all connected to the MCU control unit. The MCU control unit receives and processes data from these components, such as... Figure 3 As shown.

[0030] The working principle of the online monitoring system of this invention is as follows:

[0031] The flue gas to be tested is drawn into the sampling flue by the negative pressure of the sampling gun 4. When the flue gas flows to the heater 5, the temperature of the flue gas to be tested is heated to above the dew point temperature. Because the mass concentration of sulfuric acid mist in the ultra-low emission flue gas is low, the heating temperature is set to 200℃, at which point the flue gas is in a "dry" state. The flue gas to be tested, in a "dry" state, passes through the high-efficiency filter 7, which can filter out filterable particulate matter, keeping the flue gas to be tested in a pure gaseous state. When the flue gas to be tested flows through the high-performance dehumidification membrane 8, the moisture in the flue gas is completely absorbed by the dehumidification membrane, and the high-performance dehumidification membrane 8 does not react with other gases. The flue gas to be tested enters the monitoring condensation zone 2, and the flue gas passes through the gas mass flow meter I9. The instrument records the gas mass flow rate Q1 and velocity V1 at this time. The flue gas to be tested enters through the lower inlet of the condenser chamber 10. At this time, the control module obtains the atmospheric temperature and humidity through the ambient temperature and humidity sensor, and adjusts the temperature of the condenser chamber 10 to the ambient temperature through the feedback circuit of the semiconductor cooling chip 16. The ultrasonic oscillating sprayer 17 sprays moisture according to the atmospheric humidity fed back by the control module. At this time, the flue gas to be tested will begin to condense due to the sudden drop in temperature. The ultrasonic oscillating sprayer 17 will release ultrasonic waves at a specific frequency to promote the settling of condensed particles. The flue gas is now in a humid state and flows out through the flue gas outlet at the top of the condenser chamber 10. The flue gas passes through the glass fiber filter membrane and the high-performance dehumidification membrane 11 to intercept the unsettled condensed particles and absorb the moisture in the flue gas. The flue gas to be tested returns to a pure gaseous state and flows through the gas mass flow meter II 13. The instrument records the gas mass flow rate Q2 at this time (at this time, the gas only contains uncondensed gas). Since the gas temperature and humidity are basically the same as the ambient temperature and humidity, it can be regarded as a gaseous pollutant. The time required for the flue gas to flow through the gas mass flow meter I9 and the gas mass flow meter II 13 is denoted as Δt. The flue gas is purified by the gas purifier 14, and the pressure pump 15 provides the extraction power.

[0032] like Figure 4 As shown, the ambient temperature and humidity sensor transmits the temperature and humidity data to the MCU control unit. The MCU control unit controls the semiconductor cooling chip and the ultrasonic oscillating sprayer to maintain the temperature and humidity consistent with the atmosphere. Gas mass flow meter I9 records the mass flow rate Q1 and velocity V1 before condensation, and gas mass flow meter II13 records the mass flow rate Q2 and velocity V2 after condensation. The MCU controls the flow regulating valve 12 to make V1 = V2 (±3% error). Since the velocity and cross-sectional area of ​​the flue gas are the same when flowing through gas mass flow meter I9 and gas mass flow meter II13, the mass of condensable particulate matter can be obtained based on the law of conservation of mass: M 凝 =Δm =Δt(Q1-Q2).

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An on-line monitoring system for condensable particulate matter in flue gas of an ultra-low emission coal-fired power plant, characterized in that: The system includes a flue gas pretreatment zone (1), a monitoring and condensation zone (2), and a tail gas treatment zone (3) connected in sequence. The flue gas pretreatment zone (1) collects the flue gas to be tested and pre-treats it. The monitoring and condensation zone (2) condenses the pre-treated flue gas to condense the condensable particulate matter in the flue gas and calculates the mass of the condensable particulate matter. The tail gas treatment zone (3) purifies the gas discharged from the monitoring and condensation zone (2) and then discharges it into the atmosphere. The system also includes a control module and an atmospheric temperature and humidity sensor. The control module adjusts the temperature and humidity of the monitoring condensation zone (2) according to the atmospheric temperature and humidity collected by the atmospheric temperature and humidity sensor, so that the condensable particulate matter in the flue gas to be tested condenses and settles. The flue gas pretreatment zone (1) includes a sampling gun (4), a heater (5), a high-efficiency filter (7), and a high-performance dehumidification membrane (8) connected in sequence; the heater (5) is used to heat the flue gas to be tested to above the dew point temperature; the high-efficiency filter (7) is used to filter filterable particulate matter in the flue gas to be tested; the high-performance dehumidification membrane (8) is used to absorb moisture in the flue gas to be tested. The monitoring condensation zone (2) includes a gas mass flow meter I (9), a condensation chamber (10), a glass fiber filter membrane and a high-performance dehumidification membrane (11), a flow regulating valve (12), and a gas mass flow meter II (13) connected in sequence. The gas mass flow meter I (9) is used to detect the mass flow rate and velocity of the flue gas to be tested. The condensation chamber (10) is used to condense and settle condensable particles in the flue gas to be tested. The glass fiber filter membrane and the high-performance dehumidification membrane (11) are used to trap condensed but unsettled particles and absorb moisture in the flue gas. The gas mass flow meter II (13) is used to detect the mass flow rate and velocity of the flue gas after condensation treatment. The flow regulating valve (12) is used to regulate the velocity of the flue gas at the gas mass flow meter. The gas mass flow meter I (9), the flow regulating valve (12), and the gas mass flow meter II (13) are all connected to the control module. The control module controls the flow rate of flue gas through the flow regulating valve (12) to make the flue gas flow rates at gas mass flow meter I (9) and gas mass flow meter II (13) equal. Based on the flue gas mass flow rates detected by gas mass flow meter I (9) and gas mass flow meter II (13), the mass of condensable particulate matter in the flue gas to be tested is calculated using the law of conservation of mass. , The mass of condensable particulate matter in the flue gas to be tested. This refers to the time required for the flue gas to flow through gas mass flow meter I9 and gas mass flow meter II13. The flue gas mass flow rate recorded by gas mass flow meter I9. This is the flue gas mass flow rate recorded by gas mass flow meter II13.

2. The online monitoring system according to claim 1, characterized in that: The sampling gun (4), heater (5), high-efficiency filter (7) and high-performance dehumidification membrane (8) are all wrapped with high-temperature heat tracing pipelines.

3. The online monitoring system according to claim 1, characterized in that: The condensation chamber (10) includes a semiconductor cooling chip (16), an ultrasonic oscillating sprayer (17), and an organic adsorption layer (18); the semiconductor cooling chip (16) and the ultrasonic oscillating sprayer (17) are respectively connected to the control module, and the test flue gas in the condensation chamber (10) is condensed under the control of the control module; the organic adsorption layer (18) is used to absorb condensable particulate matter that settles during condensation.

4. The online monitoring system according to claim 1, characterized in that: The exhaust gas treatment zone (3) includes a gas purifier (14) and a vacuum pump (15); the gas purifier (14) purifies the flue gas discharged from the monitoring condensation zone (2); the vacuum pump (15) provides power for the gas flow.

5. A method for online monitoring of condensable particulate matter in the online monitoring system according to any one of claims 1 to 4, characterized in that: This method uses a high-efficiency filter (7) and a high-performance dehumidification membrane (8) to remove filterable particulate matter and moisture from the flue gas to be tested, and then records the mass flow rate of the flue gas to be tested before condensation using a gas mass flow meter I (9). and flow rate The flue gas to be tested condenses and settles in the condensation chamber (10). After the condensable particulate matter is absorbed and condensed by the organic adsorption layer (18) and the glass fiber filter membrane and high-performance dehumidification membrane (11), the remaining flue gas flows through the gas mass flow meter II (13). The gas mass flow meter II (13) records the mass flow rate of the condensed flue gas. and flow rate ; This method simultaneously controls the flow rate of flue gas through the flow regulating valve (12) so that the flue gas flow rate at gas mass flow meter I (9) and gas mass flow meter II (13) is equal, and calculates the mass of condensable particulate matter in the flue gas to be tested based on the flue gas mass flow rate detected by gas mass flow meter I (9) and gas mass flow meter II (13) using the law of conservation of mass.

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